Biodegradable sizing agents from soy protein via controlled hydrolysis and dis-entanglement for remediation of textile effluents.

PubMed

Yang, Maiping; Xu, Helan; Hou, Xiuliang; Zhang, Jie; Yang, Yiqi

2017-03-01

Fully biodegradable textile sizes with satisfactory performance properties were developed from soy protein with controlled hydrolysis and dis-entanglement to tackle the intractable environmental issues associated with the non-biodegradable polyvinyl alcohol (PVA) in textile effluents. PVA derived from petroleum is the primary sizing agent due to its excellent sizing performance on polyester-containing yarns, especially in increasingly prevailing high-speed weaving. However, due to the poor biodegradability, PVA causes serious environmental pollution, and thus, should be substituted with more environmentally friendly polymers. Soy protein treated with high amount of triethanolamine was found with acceptable sizing properties. However, triethanolamine is also non-biodegradable and originated from petroleum, therefore, is not an ideal additive. In this research, soy sizes were developed from soy protein treated with glycerol, the biodegradable triol that could also be obtained from soy. The soy sizes had good film properties, adhesion to polyester and abrasion resistance close to PVA, rendering them qualified for sizing applications. Regarding desizing, consumption of water and energy for removal of soy size could be remarkably decreased, comparing to removal of PVA. Moreover, with satisfactory degradability, the wastewater containing soy sizes was readily dischargeable after treated in activated sludge for two days. In summary, the fully biodegradable soy sizes had potential to substitute PVA for sustainable textile processing. Copyright © 2016 Elsevier Ltd. All rights reserved.

From laboratory to environmental conditions: a new approach for chemical's biodegradability assessment.

PubMed

François, Brillet; Armand, Maul; Marie-José, Durand; Thouand, Gérald

2016-09-01

With thousands of organic chemicals released every day into our environment, Europe and other continents are confronted with increased risk of health and environmental problems. Even if a strict regulation such as REgistration, Authorization and restriction of CHemicals (REACH) is imposed and followed by industry to ensure that they prove the harmlessness of their substances, not all testing procedures are designed to cope with the complexity of the environment. This is especially true for the evaluation of persistence through biodegradability assessment guidelines. Our new approach has been to adapt "in the lab" biodegradability assessment to the environmental conditions and model the probability for a biodegradation test to be positive in the form of a logistic function of both the temperature and the viable cell density. Here, a proof of this new concept is proposed with the establishment of tri-dimensional biodegradability profiles of six chemicals (sodium benzoate, 4-nitrophenol, diethylene glycol, 2,4,5-trichlorophenol, atrazine, and glyphosate) between 4 to 30 °C and 10(4) to 10(8) cells ml(-1) as can be found in environmental compartments in time and space. The results show a significant increase of the predictive power of existing screening lab-scale tests designed for soluble substances. This strategy can be complementary to those current testing strategies with the creation of new indicators to quantify environmental persistence using lab-scale tests.

The University of Minnesota Biocatalysis/Biodegradation Database: specialized metabolism for functional genomics.

PubMed Central

Ellis, L B; Hershberger, C D; Wackett, L P

1999-01-01

The University of Minnesota Biocatalysis/Biodegradation Database (UM-BBD, http://www.labmed.umn.edu/umbbd/i nde x.html) first became available on the web in 1995 to provide information on microbial biocatalytic reactions of, and biodegradation pathways for, organic chemical compounds, especially those produced by man. Its goal is to become a representative database of biodegradation, spanning the diversity of known microbial metabolic routes, organic functional groups, and environmental conditions under which biodegradation occurs. The database can be used to enhance understanding of basic biochemistry, biocatalysis leading to speciality chemical manufacture, and biodegradation of environmental pollutants. It is also a resource for functional genomics, since it contains information on enzymes and genes involved in specialized metabolism not found in intermediary metabolism databases, and thus can assist in assigning functions to genes homologous to such less common genes. With information on >400 reactions and compounds, it is poised to become a resource for prediction of microbial biodegradation pathways for compounds it does not contain, a process complementary to predicting the functions of new classes of microbial genes. PMID:9847233

Biodegradation of plastics: current scenario and future prospects for environmental safety.

PubMed

Ahmed, Temoor; Shahid, Muhammad; Azeem, Farrukh; Rasul, Ijaz; Shah, Asad Ali; Noman, Muhammad; Hameed, Amir; Manzoor, Natasha; Manzoor, Irfan; Muhammad, Sher

2018-03-01

Plastic is a general term used for a wide range of high molecular weight organic polymers obtained mostly from the various hydrocarbon and petroleum derivatives. There is an ever-increasing trend towards the production and consumption of plastics due to their extensive industrial and domestic applications. However, a wide spectrum of these polymers is non-biodegradable with few exceptions. The extensive use of plastics, lack of waste management, and casual community behavior towards their proper disposal pose a significant threat to the environment. This has raised growing concerns among various stakeholders to devise policies and innovative strategies for plastic waste management, use of biodegradable polymers especially in packaging, and educating people for their proper disposal. Current polymer degradation strategies rely on chemical, thermal, photo, and biological procedures. In the presence of proper waste management strategies coupled with industrially controlled biodegradation facilities, the use of biodegradable plastics for some applications such as packaging or health industry is a promising and attractive option for economic, environmental, and health benefits. This review highlights the classification of plastics with special emphasis on biodegradable plastics and their rational use, the identified mechanisms of plastic biodegradation, the microorganisms involved in biodegradation, and the current insights into the research on biodegradable plastics. The review has also identified the research gaps in plastic biodegradation followed by future research directions.

A Degradome-Based Polymerase Chain Reaction to Resolve the Potential of Environmental Samples for 2,4-Dichlorophenol Biodegradation.

PubMed

Ibrahim, Eslam S; Kashef, Mona T; Essam, Tamer M; Ramadan, Mohammed A

2017-12-01

A clean way to overcome environmental pollution is biodegradation. In this perspective, at the intersection of biodegradation and metagenomics, the degradome is defined as the totality of genes related to the biodegradation of a certain compound. It includes the genetic elements from both culturable and uncultured microorganisms. The possibility of assessing the biodegradation potential of an environmental samples, using a degradome-based polymerase chain reaction, was explored. 2,4-Dichlorophenol (2,4-DCP) was chosen as a model and the use of tfdB gene as a biodegradation marker was confirmed by bioinformatics study of TfdB protein. Five primer pairs were designed for the detection of different tfdB gene families. A total of 16 environmental samples were collected from Egyptian agricultural soils and wastewaters and tested for the presence of 2,4-DCP. The biodegradation capacity of 2,4-DCP was determined, for all isolated consortia, to reach up to 350 mg/l. Metagenomic DNA was extracted directly from the soil samples while successive 2,4-DCP-degrading microbial communities were enriched, with increasing concentrations of 2,4-DCP, then their DNA was extracted. The extracted DNA was tested for the distribution of the tfdB gene using a degradome-based polymerase chain reaction. tfdB-1 and tfdB-2 were detected in 5 and 9 samples, respectively. However, the co-existence of both genes was detected only in five samples. All tfdB positive samples were capable of 2,4-DCP degradation. The developed approach of assessing the potential of different environments for degrading 2,4-DCP was successfully measured in terms of accuracy (81.25%) and specificity (100%).

ENVIRONMENTAL BIODEGRADABILITY OF [14C] SINGLE-WALLED CARBON NANOTUBESBY TRAMETES VERSICOLOR AND NATURAL MICROBIAL CULTURES FOUND IN NEWBEDFORD HARBOR SEDIMENT AND AERATED WASTEWATER TREATMENT PLANT SLUDGE

EPA Science Inventory

Little is known about environmental biodegradability or biotransformations of single-walled carbon nanotubes (SWNT). Because of their strong association with aquatic organic matter, detailed knowledge of the ultimate fate and persistence of SWNT requires investigation of possible...

Phyllosphere yeasts rapidly break down biodegradable plastics

PubMed Central

2011-01-01

The use of biodegradable plastics can reduce the accumulation of environmentally persistent plastic wastes. The rate of degradation of biodegradable plastics depends on environmental conditions and is highly variable. Techniques for achieving more consistent degradation are needed. However, only a few microorganisms involved in the degradation process have been isolated so far from the environment. Here, we show that Pseudozyma spp. yeasts, which are common in the phyllosphere and are easily isolated from plant surfaces, displayed strong degradation activity on films made from poly-butylene succinate or poly-butylene succinate-co-adipate. Strains of P. antarctica isolated from leaves and husks of paddy rice displayed strong degradation activity on these films at 30°C. The type strain, P. antarctica JCM 10317, and Pseudozyma spp. strains from phyllosphere secreted a biodegradable plastic-degrading enzyme with a molecular mass of about 22 kDa. Reliable source of biodegradable plastic-degrading microorganisms are now in our hands. PMID:22126328

Phyllosphere yeasts rapidly break down biodegradable plastics.

PubMed

Kitamoto, Hiroko K; Shinozaki, Yukiko; Cao, Xiao-Hong; Morita, Tomotake; Konishi, Masaaki; Tago, Kanako; Kajiwara, Hideyuki; Koitabashi, Motoo; Yoshida, Shigenobu; Watanabe, Takashi; Sameshima-Yamashita, Yuka; Nakajima-Kambe, Toshiaki; Tsushima, Seiya

2011-11-29

The use of biodegradable plastics can reduce the accumulation of environmentally persistent plastic wastes. The rate of degradation of biodegradable plastics depends on environmental conditions and is highly variable. Techniques for achieving more consistent degradation are needed. However, only a few microorganisms involved in the degradation process have been isolated so far from the environment. Here, we show that Pseudozyma spp. yeasts, which are common in the phyllosphere and are easily isolated from plant surfaces, displayed strong degradation activity on films made from poly-butylene succinate or poly-butylene succinate-co-adipate. Strains of P. antarctica isolated from leaves and husks of paddy rice displayed strong degradation activity on these films at 30°C. The type strain, P. antarctica JCM 10317, and Pseudozyma spp. strains from phyllosphere secreted a biodegradable plastic-degrading enzyme with a molecular mass of about 22 kDa. Reliable source of biodegradable plastic-degrading microorganisms are now in our hands.

7 CFR 3201.8 - Determining life cycle costs, environmental and health benefits, and performance.

Code of Federal Regulations, 2013 CFR

2013-01-01

... Test Method for Determining Aerobic Biodegradation of Plastic Materials Under Controlled Composting Conditions”; (2) D5864“Standard Test Method for Determining the Aerobic Aquatic Biodegradation of Lubricants...“Standard Test Method for Determining the Aerobic Aquatic Biodegradation of Lubricants or Their Components...

7 CFR 2902.8 - Determining life cycle costs, environmental and health benefits, and performance.

Code of Federal Regulations, 2011 CFR

2011-01-01

... for Determining Aerobic Biodegradation of Plastic Materials Under Controlled Composting Conditions”; (2) D5864“Standard Test Method for Determining the Aerobic Aquatic Biodegradation of Lubricants or...“Standard Test Method for Determining the Aerobic Aquatic Biodegradation of Lubricants or Their Components...

7 CFR 3201.8 - Determining life cycle costs, environmental and health benefits, and performance.

Code of Federal Regulations, 2012 CFR

2012-01-01

... Test Method for Determining Aerobic Biodegradation of Plastic Materials Under Controlled Composting Conditions”; (2) D5864“Standard Test Method for Determining the Aerobic Aquatic Biodegradation of Lubricants...“Standard Test Method for Determining the Aerobic Aquatic Biodegradation of Lubricants or Their Components...

7 CFR 3201.8 - Determining life cycle costs, environmental and health benefits, and performance.

Code of Federal Regulations, 2014 CFR

2014-01-01

... Test Method for Determining Aerobic Biodegradation of Plastic Materials Under Controlled Composting Conditions”; (2) D5864“Standard Test Method for Determining the Aerobic Aquatic Biodegradation of Lubricants...“Standard Test Method for Determining the Aerobic Aquatic Biodegradation of Lubricants or Their Components...

Ionic liquid biodegradability depends on specific wastewater microbial consortia.

PubMed

Docherty, Kathryn M; Aiello, Steven W; Buehler, Barbara K; Jones, Stuart E; Szymczyna, Blair R; Walker, Katherine A

2015-10-01

Complete biodegradation of a newly-synthesized chemical in a wastewater treatment plant (WWTP) eliminates the potential for novel environmental pollutants. However, differences within- and between-WWTP microbial communities may alter expectations for biodegradation. WWTP communities can also serve as a source of unique consortia that, when enriched, can metabolize chemicals that tend to resist degradation, but are otherwise promising green alternatives. We tested the biodegradability of three ionic liquids (ILs): 1-octyl-3-methylpyridinium bromide (OMP), 1-butyl-3-methylpyridinium bromide (BMP) and 1-butyl-3-methylimidazolium chloride (BMIM). We performed tests using communities from two WWTPs at three time points. Site-specific and temporal variation both influenced community composition, which impacted the success of OMP biodegradability. Neither BMP nor BMIM degraded in any test, suggesting that these ILs are unlikely to be removed by traditional treatment. Following standard biodegradation assays, we enriched for three consortia that were capable of quickly degrading OMP, BMP and BMIM. Our results indicate WWTPs are not functionally redundant with regard to biodegradation of specific ionic liquids. However, consortia can be enriched to degrade chemicals that fail biodegradability assays. This information can be used to prepare pre-treatment procedures and prevent environmental release of novel pollutants. Copyright © 2015 Elsevier Ltd. All rights reserved.

The second green revolution? Production of plant-based biodegradable plastics.

PubMed

Mooney, Brian P

2009-03-01

Biodegradable plastics are those that can be completely degraded in landfills, composters or sewage treatment plants by the action of naturally occurring micro-organisms. Truly biodegradable plastics leave no toxic, visible or distinguishable residues following degradation. Their biodegradability contrasts sharply with most petroleum-based plastics, which are essentially indestructible in a biological context. Because of the ubiquitous use of petroleum-based plastics, their persistence in the environment and their fossil-fuel derivation, alternatives to these traditional plastics are being explored. Issues surrounding waste management of traditional and biodegradable polymers are discussed in the context of reducing environmental pressures and carbon footprints. The main thrust of the present review addresses the development of plant-based biodegradable polymers. Plants naturally produce numerous polymers, including rubber, starch, cellulose and storage proteins, all of which have been exploited for biodegradable plastic production. Bacterial bioreactors fed with renewable resources from plants--so-called 'white biotechnology'--have also been successful in producing biodegradable polymers. In addition to these methods of exploiting plant materials for biodegradable polymer production, the present review also addresses the advances in synthesizing novel polymers within transgenic plants, especially those in the polyhydroxyalkanoate class. Although there is a stigma associated with transgenic plants, especially food crops, plant-based biodegradable polymers, produced as value-added co-products, or, from marginal land (non-food), crops such as switchgrass (Panicum virgatum L.), have the potential to become viable alternatives to petroleum-based plastics and an environmentally benign and carbon-neutral source of polymers.

Environmental performance of bio-based and biodegradable plastics: the road ahead.

PubMed

Lambert, Scott; Wagner, Martin

2017-11-13

Future plastic materials will be very different from those that are used today. The increasing importance of sustainability promotes the development of bio-based and biodegradable polymers, sometimes misleadingly referred to as 'bioplastics'. Because both terms imply "green" sources and "clean" removal, this paper aims at critically discussing the sometimes-conflicting terminology as well as renewable sources with a special focus on the degradation of these polymers in natural environments. With regard to the former we review innovations in feedstock development (e.g. microalgae and food wastes). In terms of the latter, we highlight the effects that polymer structure, additives, and environmental variables have on plastic biodegradability. We argue that the 'biodegradable' end-product does not necessarily degrade once emitted to the environment because chemical additives used to make them fit for purpose will increase the longevity. In the future, this trend may continue as the plastics industry also is expected to be a major user of nanocomposites. Overall, there is a need to assess the performance of polymer innovations in terms of their biodegradability especially under realistic waste management and environmental conditions, to avoid the unwanted release of plastic degradation products in receiving environments.

Biodegradation of aged diesel in diverse soil matrixes: impact of environmental conditions and bioavailability on microbial remediation capacity.

PubMed

Sutton, Nora B; van Gaans, Pauline; Langenhoff, Alette A M; Maphosa, Farai; Smidt, Hauke; Grotenhuis, Tim; Rijnaarts, Huub H M

2013-07-01

While bioremediation of total petroleum hydrocarbons (TPH) is in general a robust technique, heterogeneity in terms of contaminant and environmental characteristics can impact the extent of biodegradation. The current study investigates the implications of different soil matrix types (anthropogenic fill layer, peat, clay, and sand) and bioavailability on bioremediation of an aged diesel contamination from a heterogeneous site. In addition to an uncontaminated sample for each soil type, samples representing two levels of contamination (high and low) were also used; initial TPH concentrations varied between 1.6 and 26.6 g TPH/kg and bioavailability between 36 and 100 %. While significant biodegradation occurred during 100 days of incubation under biostimulating conditions (64.4-100 % remediation efficiency), low bioavailability restricted full biodegradation, yielding a residual TPH concentration. Respiration levels, as well as the abundance of alkB, encoding mono-oxygenases pivotal for hydrocarbon metabolism, were positively correlated with TPH degradation, demonstrating their usefulness as a proxy for hydrocarbon biodegradation. However, absolute respiration and alkB presence were dependent on soil matrix type, indicating the sensitivity of results to initial environmental conditions. Through investigating biodegradation potential across a heterogeneous site, this research illuminates the interplay between soil matrix type, bioavailability, and bioremediation and the implications of these parameters for the effectiveness of an in situ treatment.

Evaluating the primary and ready biodegradability of dianilinodithiophosphoric acid.

PubMed

Lin, Weixiong; Sun, Shuiyu; Xu, Pingting; Dai, Yongkang; Ren, Jie

2016-04-01

Dianilinodithiophosphoric acid (DDA) is widely used as sulfide mineral flotation collector in China. It is necessary to investigate the biodegradability of DDA to provide the fundamental knowledge to assess the environmental fate in the risk assessment of DDA and to design and operate the DDA flotation wastewater biological treatment plant. In the present study, the primary and ready aerobic biodegradations of DDA were studied and the primary biodegradation kinetic model of DDA was developed. The results show that DDA displays a good primary biodegradability and its biodegradation ratio reaches 99.8 % in 7 days. In contrast, DDA is not easily ready biodegradable; hence, it is a partially biodegradable organic compound. The primary aerobic biodegradation kinetics can be described using the first-order reaction kinetics equation: C = 19.72191e(-0.01513t).

Phthalates biodegradation in the environment.

PubMed

Liang, Da-Wei; Zhang, Tong; Fang, Herbert H P; He, Jianzhong

2008-08-01

Phthalates are synthesized in massive amounts to produce various plastics and have become widespread in environments following their release as a result of extensive usage and production. This has been of an environmental concern because phthalates are hepatotoxic, teratogenic, and carcinogenic by nature. Numerous studies indicated that phthalates can be degraded by bacteria and fungi under aerobic, anoxic, and anaerobic conditions. This paper gives a review on the biodegradation of phthalates and includes the following aspects: (1) the relationship between the chemical structure of phthalates and their biodegradability, (2) the biodegradation of phthalates by pure/mixed cultures, (3) the biodegradation of phthalates under various environments, and (4) the biodegradation pathways of phthalates.

Colorado Scientists Win National Award

Science.gov Websites

environmentally friendly products, such as biodegradable pesticides and gasoline additives. Dr. Joseph Bozell and manufacture biodegradable herbicides and pesticides and an oxygenate for cleaner burning gasoline. Biomass

Biodegradability of carbon nanotube/polymer nanocomposites under aerobic mixed culture conditions.

PubMed

Phan, Duc C; Goodwin, David G; Frank, Benjamin P; Bouwer, Edward J; Fairbrother, D Howard

2018-10-15

The properties and commercial viability of biodegradable polymers can be significantly enhanced by the incorporation of carbon nanotubes (CNTs). The environmental impact and persistence of these carbon nanotube/polymer nanocomposites (CNT/PNCs) after disposal will be strongly influenced by their microbial interactions, including their biodegradation rates. At the end of consumer use, CNT/PNCs will encounter diverse communities of microorganisms in landfills, surface waters, and wastewater treatment plants. To explore CNT/PNC biodegradation under realistic environmental conditions, the effect of multi-wall CNT (MWCNT) incorporation on the biodegradation of polyhydroxyalkanoates (PHA) was investigated using a mixed culture of microorganisms from wastewater. Relative to unfilled PHA (0% w/w), the MWCNT loading (0.5-10% w/w) had no statistically significant effect on the rate of PHA matrix biodegradation. Independent of the MWCNT loading, the extent of CNT/PNC mass remaining closely corresponded to the initial mass of CNTs in the matrix suggesting a lack of CNT release. CNT/PNC biodegradation was complete in approximately 20 days and resulted in the formation of a compressed CNT mat that retained the shape of the initial CNT/PNC. This study suggests that although CNTs have been shown to be cytotoxic towards a range of different microorganisms, this does not necessarily impact the biodegradation of the surrounding polymer matrix in mixed culture, particularly in situations where the polymer type and/or microbial population favor rapid polymer biodegradation. Copyright © 2018 Elsevier B.V. All rights reserved.

A comparative study of biodegradability of a carcinogenic aromatic amine (4,4'-diaminodiphenylmethane) with OECD 301 test methods.

PubMed

Mei, Cheng-Fang; Liu, Yan-Zhen; Long, Wei-Nian; Sun, Guo-Ping; Zeng, Guo-Qu; Xu, Mei-Ying; Luan, Tian-Gang

2015-01-01

4,4'-Diaminodiphenylmethane (MDA) is a widely used compound in industries. Studies on the biodegradability of MDA are necessary for environmental hazard identification and risk assessment. Previous studies have suggested that MDA was not readily biodegradable. In the present study, three batches of biodegradation tests (OECD 301A, B, D and F tests) were performed on MDA in June, August and December of 2012. MDA was found to be readily biodegradable and produced colored intermediates in the 301A, B and F test systems. MDA biodegradation measurements were consistent among the three batches of tests. Differences in the extent of biodegradation determined in different methods originated from different test conditions and assessment endpoints. The 301D test has stringent test conditions and is usually performed on chemicals that are toxic to microorganisms, so the test results obtained from 301D tests are less meaningful for evaluating the biodegradability of MDA. The low MDA biodegradation measurements in the 301B tests compared to the 301A and F tests were due to the assessment method, which did not account for MDA incorporation into biomass in its calculation of CO2 formation rate. The differences in the biodegradation rates, as measured by the different OECD 301 test systems, could also be related to the structure and properties of the chemical. For test substances that can be assessed by all OECD 301 test methods, the highest biodegradation values may be obtained from the 301A and F test methods. This study provides new information to assess the environmental fate in the risk assessment of MDA. Copyright © 2014 Elsevier Inc. All rights reserved.

Biodegradation of BTEX mixture by Pseudomonas putida YNS1 isolated from oil-contaminated soil.

PubMed

You, Youngnam; Shim, Jaehong; Cho, Choa-Hyoung; Ryu, Moon-Hee; Shea, Patrick J; Kamala-Kannan, Seralathan; Chae, Jong-Chan; Oh, Byung-Taek

2013-05-01

The presence of mixed contaminants, such as BTEX (benzene, toluene, ethylbenzene and xylene isomers) can affect the biodegradation, fate and environmental impacts of each compound. To understand the influence of interactions among BTEX compounds on their biodegradation, four bacteria were isolated from oil-contaminated soil and assayed for BTEX biodegradation in vitro. The isolate exhibiting maximum biodegradation was identified as Pseudomonas putida based on the 16S rDNA sequence. The biodegradation of the BTEX compounds was greatly influenced by pH, temperature, and salinity. Substrate mixture studies (binary, tertiary and quaternary) revealed that the presence of toluene increased the biodegradation rate of benzene, ethylbenzene, and xylene. © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Biodegradation of plastics.

PubMed

Shimao, M

2001-06-01

Widespread studies on the biodegradation of plastics have been carried out in order to overcome the environmental problems associated with synthetic plastic waste. Recent work has included studies of the distribution of synthetic polymer-degrading microorganisms in the environment, the isolation of new microorganisms for biodegradation, the discovery of new degradation enzymes, and the cloning of genes for synthetic polymer-degrading enzymes.

Biological degradation of plastics: a comprehensive review.

PubMed

Shah, Aamer Ali; Hasan, Fariha; Hameed, Abdul; Ahmed, Safia

2008-01-01

Lack of degradability and the closing of landfill sites as well as growing water and land pollution problems have led to concern about plastics. With the excessive use of plastics and increasing pressure being placed on capacities available for plastic waste disposal, the need for biodegradable plastics and biodegradation of plastic wastes has assumed increasing importance in the last few years. Awareness of the waste problem and its impact on the environment has awakened new interest in the area of degradable polymers. The interest in environmental issues is growing and there are increasing demands to develop material which do not burden the environment significantly. Biodegradation is necessary for water-soluble or water-immiscible polymers because they eventually enter streams which can neither be recycled nor incinerated. It is important to consider the microbial degradation of natural and synthetic polymers in order to understand what is necessary for biodegradation and the mechanisms involved. This requires understanding of the interactions between materials and microorganisms and the biochemical changes involved. Widespread studies on the biodegradation of plastics have been carried out in order to overcome the environmental problems associated with synthetic plastic waste. This paper reviews the current research on the biodegradation of biodegradable and also the conventional synthetic plastics and also use of various techniques for the analysis of degradation in vitro.

Environmental fate of naproxen, carbamazepine and triclosan in wastewater, surface water and wastewater irrigated soil - Results of laboratory scale experiments.

PubMed

Durán-Álvarez, J C; Prado, B; González, D; Sánchez, Y; Jiménez-Cisneros, B

2015-12-15

Lab-scale photolysis, biodegradation and transport experiments were carried out for naproxen, carbamazepine and triclosan in soil, wastewater and surface water from a region where untreated wastewater is used for agricultural irrigation. Results showed that both photolysis and biodegradation occurred for the three emerging pollutants in the tested matrices as follows: triclosan>naproxen>carbamazepine. The highest photolysis rate for the three pollutants was obtained in experiments using surface water, while biodegradation rates were higher in wastewater and soil than in surface water. Carbamazepine showed to be recalcitrant to biodegradation both in soil and water; although photolysis occurred at a higher level than biodegradation, this compound was poorly degraded by natural processes. Transport experiments showed that naproxen was the most mobile compound through the first 30cm of the soil profile; conversely, the mobility of carbamazepine and triclosan through the soil was delayed. Biodegradation of target pollutants occurred within soil columns during transport experiments. Triclosan was not detected either in leachates or the soil in columns, suggesting its complete biodegradation. Data of these experiments can be used to develop more reliable fate-on-the-field and environmental risk assessment studies. Copyright © 2015 Elsevier B.V. All rights reserved.

Anaerobic Biodegradation of Detergent Surfactants

PubMed Central

Merrettig-Bruns, Ute; Jelen, Erich

2009-01-01

Detergent surfactants can be found in wastewater in relevant concentrations. Most of them are known as ready degradable under aerobic conditions, as required by European legislation. Far fewer surfactants have been tested so far for biodegradability under anaerobic conditions. The natural environment is predominantly aerobic, but there are some environmental compartments such as river sediments, sub-surface soil layer and anaerobic sludge digesters of wastewater treatment plants which have strictly anaerobic conditions. This review gives an overview on anaerobic biodegradation processes, the methods for testing anaerobic biodegradability, and the anaerobic biodegradability of different detergent surfactant types (anionic, nonionic, cationic, amphoteric surfactants).

Microbial degradation on glacier surface is the missing piece of environmental fate of pesticides in cold areas

NASA Astrophysics Data System (ADS)

Ambrosini, Roberto; Ferrario, Claudia; Pittino, Francesca; Tagliaferri, Ilario; Gandolfi, Isabella; Bestetti, Giuseppina; Azzoni, Roberto S.; Diolaiuti, Guglielmina A.; Smiraglia, Claudio; Franzetti, Andrea; Villa, Sara

2017-04-01

Organic contaminants deposited on glacier surfaces undergo different partition and degradation processes which determine their environmental fate and accumulation into the trophic chains. Among these processes, biodegradation by supraglacial bacteria has been neglected so far. To assess the relevance of biodegradative processes, in situ microcosm experiments were conducted simulating cryoconite hole systems on an Alpine glacier exposed to the organophosphorus insecticide chlorpyrifos (CPF) as model of xenobiotic molecule which accumulate on glaciers after medium range transports. Results showed that biodegradation is the most efficient process contributing to the removal of CPF on the glacier surface. The high concentrations of CPF in cryoconite and its half-life in the range of 35 - 69 days indicated that biodegradation process can significantly contrast the release of CPF transported on glaciers. Moreover, the metabolic versatility of cryoconite bacteria suggest that these habitats might contribute to the degradation of a wide class of pollutants with different physical-chemical properties. Metagenomics data indicated that photoheterotrophic bacteria might be involved in the biodegradation of CPF by using light to supplement their metabolic demands, thus contributing to the biological removal of CPF without the constrain of using this pesticide as sole energy source. In conclusion. cryoconite might act as a "biofilter" for organic pollutants on glaciers by accumulating them and promoting their biodegradation. Owing to its relevance, the contribution of cryoconite to the removal of organic pollutants should be included in the models predicting the environmental fate of these compounds in cold areas.

Ecotoxicity by the biodegradation of alkylphenol polyethoxylates depends on the effect of trace elements.

PubMed

Hotta, Yudai; Hosoda, Akifumi; Sano, Fumihiko; Wakayama, Manabu; Niwa, Katsuki; Yoshikawa, Hiromichi; Tamura, Hiroto

2010-01-27

The bacteria Sphingomonas sp. strain BSN22, isolated from bean fields, degraded octylphenol polyethoxylates (OPEO(n)) to octylphenol (OP) under aerobic conditions. This biodegradation mechanism proceeded by the following two-step degradation process: (1) degradation of OPEO(n) to octylphenol triethoxylate (OPEO(3)), (2) degradation from OPEO(3) to OP via octylphenoxy acetic acid (OPEC(1)). The chemical structure of OPEC(1) was confirmed by analysis using (18)O-labeled water. Quantitative studies revealed that magnesium (Mg(2+)) and calcium (Ca(2+)) ions were essential for the biodegradation of OPEO(n). Furthermore, the rate of biodegradation was especially accelerated by ferric ions (Fe(3+)), and the accumulated amounts of endocrine active chemicals, such as OP, OPEO(1), and OPEC(1), significantly increased to the concentration of 22.8, 221.7, and 961.1 microM in the presence of 37.0 microM Fe(3+), respectively. This suggests that environmental elements significantly influence the resultant ecotoxicity as well as the rate of their biodegradation in the environment. This study on the mechanism of OPEO(n) biodegradation may play an important role in understanding and managing environmental safety, including drinking water safety.

Enantioselective biodegradation of the pyrethroid (±)-lambda-cyhalothrin by marine-derived fungi.

PubMed

Birolli, Willian G; Vacondio, Bruna; Alvarenga, Natália; Seleghim, Mirna H R; Porto, André L M

2018-04-01

The contamination of agricultural lands by pesticides is a serious environmental issue. Consequently, the development of bioremediation methods for different active ingredients, such as pyrethroids, is essential. In this study, the enantioselective biodegradation of (±)-lambda-cyhalothrin ((±)-LC) by marine-derived fungi was studied. Experiments were performed with different fungi strains (Aspergillus sp. CBMAI 1829, Acremonium sp. CBMAI 1676, Microsphaeropsis sp. CBMAI 1675 and Westerdykella sp. CBMAI 1679) in 3% malt liquid medium with 100 mg L -1 of (±)-LC. All strains biodegraded this insecticide and the residual concentrations of (±)-LC (79.2-55.2 mg L -1 , i.e., 20.8-44.8% biodegradation), their enantiomeric excesses (2-42% ee) and the 3-phenoxybenzoic acid (PBAc) concentrations (0.0-4.1 mg L -1 ) were determined. In experiments for 28 days of biodegradation in the absence and presence of artificial seawater (ASW) with the most efficient strain Aspergillus sp. CBMAI 1829, increasing concentrations of PBAc with (0.0-4.8 mg L -1 ) and without ASW (0.0-15.3 mg L -1 ) were observed. In addition, a partial biodegradation pathway was proposed. All the evaluated strains biodegraded preferentially the (1R,3R,αS)-gamma-cyhalothrin enantiomer. Therefore, marine-derived fungi enantioselectively biodegraded (±)-LC and can be applied in future studies for bioremediation of contaminated areas. This enantioselective biodegradation indicates that the employment of the most active enantiomer GC as insecticide not only enable the use of a lower amount of pesticide, but also a more easily biodegradable product, reducing the possibility of environmental contamination. Copyright © 2018 Elsevier Ltd. All rights reserved.

Activated sludge is a potential source for production of biodegradable plastics from wastewater.

PubMed

Khardenavis, A; Guha, P K; Kumar, M S; Mudliar, S N; Chakrabarti, T

2005-05-01

Increased utilization of synthetic plastics caused severe environmental pollution due to their non-biodegradable nature. In the search for environmentally friendly materials to substitute for conventional plastics, different biodegradable plastics have been developed by microbial fermentations. However, limitations of these materials still exist due to high cost. This study aims at minimization of cost for the production of biodegradable plastics P(3HB) and minimization of environmental pollution. The waste biological sludge generated at wastewater treatment plants is used for the production of P(3HB) and wastewater is used as carbon source. Activated sludge was induced by controlling the carbon: nitrogen ratio to accumulate storage polymer. Initially polymer accumulation was studied by using different carbon and nitrogen sources. Maximum accumulation of polymer was observed with carbon source acetic acid and diammonium hydrogen phosphate (DAHP) as nitrogen source. Further studies were carried out to optimize the carbon: nitrogen ratios using acetic acid and DAHP. A maximum of 65.84% (w/w) P(3HB) production was obtained at C/N ratio of 50 within 96 hours of incubation.

Biodegradation of acetanilide herbicides acetochlor and butachlor in soil.

PubMed

Ye, Chang-ming; Wang, Xing-jun; Zheng, He-hui

2002-10-01

The biodegradation of two acetanilide herbicides, acetochlor and butachlor in soil after other environmental organic matter addition were measured during 35 days laboratory incubations. The herbicides were applied to soil alone, soil-SDBS (sodium dodecylbenzene sulfonate) mixtures and soil-HA (humic acid) mixtures. Herbicide biodegradation kinetics were compared in the different treatment. Biodegradation products of herbicides in soil alone samples were identified by GC/MS at the end of incubation. Addition of SDBS and HA to soil decreased acetochlor biodegradation, but increased butachlor biodegradation. The biodegradation half-life of acetochlor and butachlor in soil alone, soil-SDBS mixtures and soil-HA mixtures were 4.6 d, 6.1 d and 5.4 d and 5.3 d, 4.9 d and 5.3 d respectively. The biodegradation products were hydroxyacetochlor and 2-methyl-6-ethylaniline for acetochlor, and hydroxybutachlor and 2,6-diethylaniline for butachlor.

Acquisition of an X-Ray Diffractometer with WAXS and SAXS for Materials Research

DTIC Science & Technology

2015-03-31

2. This ligand is known as a sensitizer for applications in dye -sensitized solar cells, and the presence of the amino groups could potentially...achieve different surface properties, thus making them excellent candidates for use as fillers in bio-based biodegradable composite materials...These CNCs are environmentally safe sustainable, biodegradable , carbon neutral, and have low environmental, health and safety risks. Figure 9 below

MOLECULAR BASIS OF BIODEGRADATION OF CHLOROAROMATIC COMPOUNDS

EPA Science Inventory

Chlorinated aromatic hydrocarbons are widely used in industry and agriculture, and comprise the bulk of environmental pollutants. Although simple aromatic compounds are biodegradable by a variety of degradative pathways, their halogenated counterparts are more resistant to bacter...

Development of an Environmental Fate Simulator for New and Proposed Military Unique Munition Compounds

DTIC Science & Technology

2015-05-07

i.e., methylenedintramine) is susceptible to further biodegradation resulting in the formation of N20 and CO2. Developing the capability to predict...ensuring complete biodegradation of the munition compound into harmless products. Methylenedinitramine from RDX degradation can form from either...anaerobic biodegradation . Furthermore, only those transformation processes that are currently supported by reaction libraries will be functional

Biodegradable and edible gelatine actuators for use as artificial muscles

NASA Astrophysics Data System (ADS)

Chambers, L. D.; Winfield, J.; Ieropoulos, I.; Rossiter, J.

2014-03-01

The expense and use of non-recyclable materials often requires the retrieval and recovery of exploratory robots. Therefore, conventional materials such as plastics and metals in robotics can be limiting. For applications such as environmental monitoring, a fully biodegradable or edible robot may provide the optimum solution. Materials that provide power and actuation as well as biodegradability provide a compelling dimension to future robotic systems. To highlight the potential of novel biodegradable and edible materials as artificial muscles, the actuation of a biodegradable hydrogel was investigated. The fabricated gelatine based polymer gel was inexpensive, easy to handle, biodegradable and edible. The electro-mechanical performance was assessed using two contactless, parallel stainless steel electrodes immersed in 0.1M NaOH solution and fixed 40 mm apart with the strip actuator pinned directly between the electrodes. The actuation displacement in response to a bias voltage was measured over hydration/de-hydration cycles. Long term (11 days) and short term (1 hour) investigations demonstrated the bending behaviour of the swollen material in response to an electric field. Actuation voltage was low (<10 V) resulting in a slow actuation response with large displacement angles (<55 degrees). The stability of the immersed material decreased within the first hour due to swelling, however, was recovered on de-hydrating between actuations. The controlled degradation of biodegradable and edible artificial muscles could help to drive the development of environmentally friendly robotics.

Biodegradable Pectin/clay Aerogels

USDA-ARS?s Scientific Manuscript database

Biodegradable, foamlike materials based on renewable pectin and sodium montmorillonite clay were fabricated through a simple, environmentally friendly freeze-drying process. Addition of multivalent cations (Ca2+ and Al3+) resulted in apparent crosslinking of the polymer, and enhancement of aerogel p...

Prospects for microbiological solutions to environmental pollution with plastics.

PubMed

Krueger, Martin C; Harms, Hauke; Schlosser, Dietmar

2015-11-01

Synthetic polymers, commonly named plastics, are among the most widespread anthropogenic pollutants of marine, limnic and terrestrial ecosystems. Disruptive effects of plastics are known to threaten wildlife and exert effects on natural food webs, but signs for and knowledge on plastic biodegradation are limited. Microorganisms are the most promising candidates for an eventual bioremediation of environmental plastics. Laboratory studies have reported various effects of microorganisms on many types of polymers, usually by enzymatic hydrolysis or oxidation. However, most common plastics have proved to be highly recalcitrant even under conditions known to favour microbial degradation. Knowledge on environmental degradation is yet scarcer. With this review, we provide a comprehensive overview of the current knowledge on microbiological degradation of several of the most common plastic types. Furthermore, we illustrate the analytical challenges concerning the evaluation of plastic biodegradation as well as constraints likely standing against the evolution of effective biodegradation pathways.

BIOB: a mathematical model for the biodegradation of low solubility hydrocarbons.

PubMed

Geng, Xiaolong; Boufadel, Michel C; Personna, Yves R; Lee, Ken; Tsao, David; Demicco, Erik D

2014-06-15

Modeling oil biodegradation is an important step in predicting the long term fate of oil on beaches. Unfortunately, existing models do not account mechanistically for environmental factors, such as pore water nutrient concentration, affecting oil biodegradation, rather in an empirical way. We present herein a numerical model, BIOB, to simulate the biodegradation of insoluble attached hydrocarbon. The model was used to simulate an experimental oil spill on a sand beach. The biodegradation kinetic parameters were estimated by fitting the model to the experimental data of alkanes and aromatics. It was found that parameter values are comparable to their counterparts for the biodegradation of dissolved organic matter. The biodegradation of aromatics was highly affected by the decay of aromatic biomass, probably due to its low growth rate. Numerical simulations revealed that the biodegradation rate increases by 3-4 folds when the nutrient concentration is increased from 0.2 to 2.0 mg N/L. Published by Elsevier Ltd.

Integrated Inquiry.

ERIC Educational Resources Information Center

Trautmann, Nancy M.; Carlsen, William S.; Krasny, Marianne E.; Cunningham, Christine M.

2000-01-01

Introduces the Environmental Inquiry (EI) program which focuses on five topics: watershed dynamics, environmental toxicology, ecology of invasive species, biodegradations, and urban ecosystem modeling. (YDS)

Biodegradability study of high-erucic-acid-rapeseed-oil-based lubricant additives

DOE Office of Scientific and Technical Information (OSTI.GOV)

Zhou, E.; Crawford, R.L.; Shanahan, A.

1995-12-31

A variety of high-erucic-acid-rapeseed (HEAR)-oil-based lubricants, lubricant additives, and greases were examined for biodegradability at the University of Idaho Center for Hazardous Waste Remediation Research. Two standard biodegradability tests were employed, a currently accepted US Environmental Protection Agency (EPA) protocol and the Sturm Test. As is normal for tests that employ variable inocula such as sewage as a source of microorganisms, these procedures yielded variable results from one repetition to another. However, a general trend of rapid and complete biodegradability of the HEAR-oil-based materials was observed.

Biodegradability of pentachlorophenol in the environment: A literature review

DOE Office of Scientific and Technical Information (OSTI.GOV)

Nakles, D.

1993-04-01

Pentachlorophenol has been widely used as a wood preserving agent for over 50 years to treat millions of electrical utility poles and crossarms. Treatment of poles with pentachlorophenol has in some cases resulted in contamination of soils, groundwater, and surface water. Environmental releases are a concern because of the potential toxicity of pentachlorophenol and its stringent regulation. Microbiological degradation of pentachlorophenol in environmental media has been demonstrated in numerous cases. The potential for pentachlorophenol to be biologically degraded is of interest to the electrical utility industry for two reasons. First, it is a factor in understanding the probable fate ofmore » pentachlorophenol where it has been released into the environment, and second, its biodegradability can potentially result in effective and economical treatment strategies for soils, water, and subsurface environments. The objective of this literature review is to collect a baseline of information on the biodegradability of pentachlorophenol in soils, surface water, and groundwater for the electric utility industry. The focus of the electric utility industry's interest in the environmental management and control of pentachlorophenol is primarily in the management of environmental media, particularly soils, that may have become incidentally contaminated with pentachlorophenol in association with the treatment, storage, or use of utility poles and crossarms. The review of the literature has found that [open quotes]unassisted[close quotes] biodegradation of pentachlorophenol in aquatic, soil, and subsurface environments may occur, presumably if there is an acclimated microbial population of sufficient density. Aerobic conditions appear to be most conducive to biodegradation in these cases. Several studies have shown that with an acclimated, mixed culture and conventional wastewater treatment approaches, pentachlorophenol can be effectively treated in water.« less

Biodegradability of pentachlorophenol in the environment: A literature review. Final report

DOE Office of Scientific and Technical Information (OSTI.GOV)

Nakles, D.

1993-04-01

Pentachlorophenol has been widely used as a wood preserving agent for over 50 years to treat millions of electrical utility poles and crossarms. Treatment of poles with pentachlorophenol has in some cases resulted in contamination of soils, groundwater, and surface water. Environmental releases are a concern because of the potential toxicity of pentachlorophenol and its stringent regulation. Microbiological degradation of pentachlorophenol in environmental media has been demonstrated in numerous cases. The potential for pentachlorophenol to be biologically degraded is of interest to the electrical utility industry for two reasons. First, it is a factor in understanding the probable fate ofmore » pentachlorophenol where it has been released into the environment, and second, its biodegradability can potentially result in effective and economical treatment strategies for soils, water, and subsurface environments. The objective of this literature review is to collect a baseline of information on the biodegradability of pentachlorophenol in soils, surface water, and groundwater for the electric utility industry. The focus of the electric utility industry`s interest in the environmental management and control of pentachlorophenol is primarily in the management of environmental media, particularly soils, that may have become incidentally contaminated with pentachlorophenol in association with the treatment, storage, or use of utility poles and crossarms. The review of the literature has found that {open_quotes}unassisted{close_quotes} biodegradation of pentachlorophenol in aquatic, soil, and subsurface environments may occur, presumably if there is an acclimated microbial population of sufficient density. Aerobic conditions appear to be most conducive to biodegradation in these cases. Several studies have shown that with an acclimated, mixed culture and conventional wastewater treatment approaches, pentachlorophenol can be effectively treated in water.« less

External validation of EPIWIN biodegradation models.

PubMed

Posthumus, R; Traas, T P; Peijnenburg, W J G M; Hulzebos, E M

2005-01-01

The BIOWIN biodegradation models were evaluated for their suitability for regulatory purposes. BIOWIN includes the linear and non-linear BIODEG and MITI models for estimating the probability of rapid aerobic biodegradation and an expert survey model for primary and ultimate biodegradation estimation. Experimental biodegradation data for 110 newly notified substances were compared with the estimations of the different models. The models were applied separately and in combinations to determine which model(s) showed the best performance. The results of this study were compared with the results of other validation studies and other biodegradation models. The BIOWIN models predict not-readily biodegradable substances with high accuracy in contrast to ready biodegradability. In view of the high environmental concern of persistent chemicals and in view of the large number of not-readily biodegradable chemicals compared to the readily ones, a model is preferred that gives a minimum of false positives without a corresponding high percentage false negatives. A combination of the BIOWIN models (BIOWIN2 or BIOWIN6) showed the highest predictive value for not-readily biodegradability. However, the highest score for overall predictivity with lowest percentage false predictions was achieved by applying BIOWIN3 (pass level 2.75) and BIOWIN6.

Pyrene biodegradation with layer-by-layer assembly bio-microcapsules.

PubMed

Deng, Fucai; Zhang, Zhengfang; Yang, Chen; Guo, Chuling; Lu, Guining; Dang, Zhi

2017-04-01

Biotechnology is considered as a promising technology for the removal of polycyclic aromatic hydrocarbons from the environment. Free bacteria are often sensitive to some biotic and abiotic factors in the environment to the extent that their ability to effect biodegradation of organic pollutants, such as polycyclic aromatic hydrocarbons, is hampered. Consequently, it is imperative to carry out investigations into biological systems that will obviate or aid tolerance of bacteria to harsh environmental conditions. Chitosan/alginate bio-microcapsules produced using layer-by-layer (LBL) assembly method were tested for pyrene (PYR) biodegradation under harsh environmental conditions. Morphology observation indicated that the flake bio-microcapsules could be successfully prepared through LBL assembly method. Surface analysis showed that the bio-microcapsules had large fractions of mesopores. The results of the biodegradation experiments revealed that the 95% of 10mgL -1 PYR could be removed by the bacteria encapsulated chitosan/alginate bio-microcapsules in 3 days, which was higher than that of the free bacteria (59%). Compared to the free cells, the bacteria encapsulated chitosan/alginate bio-microcapsules produced 1-6 times higher PYR biodegradation rates at a high initial PYR concentration (50mgL -1 ) and extremely low pH values (pH =3) or temperatures (10°C or 40°C), as well as high salt stress. The results indicated that bacteria in microcapsules treatment gained a much higher tolerance to environmental stress and LBL bio-microcapsule could be promising candidate for remediating the organic pollutants. Copyright © 2016 Elsevier Inc. All rights reserved.

A new in silico classification model for ready biodegradability, based on molecular fragments.

PubMed

Lombardo, Anna; Pizzo, Fabiola; Benfenati, Emilio; Manganaro, Alberto; Ferrari, Thomas; Gini, Giuseppina

2014-08-01

Regulations such as the European REACH (Registration, Evaluation, Authorization and restriction of Chemicals) often require chemicals to be evaluated for ready biodegradability, to assess the potential risk for environmental and human health. Because not all chemicals can be tested, there is an increasing demand for tools for quick and inexpensive biodegradability screening, such as computer-based (in silico) theoretical models. We developed an in silico model starting from a dataset of 728 chemicals with ready biodegradability data (MITI-test Ministry of International Trade and Industry). We used the novel software SARpy to automatically extract, through a structural fragmentation process, a set of substructures statistically related to ready biodegradability. Then, we analysed these substructures in order to build some general rules. The model consists of a rule-set made up of the combination of the statistically relevant fragments and of the expert-based rules. The model gives good statistical performance with 92%, 82% and 76% accuracy on the training, test and external set respectively. These results are comparable with other in silico models like BIOWIN developed by the United States Environmental Protection Agency (EPA); moreover this new model includes an easily understandable explanation. Copyright © 2014 Elsevier Ltd. All rights reserved.

Effects of chronic pollution and water flow intermittency on stream biofilms biodegradation capacity.

PubMed

Rožman, Marko; Acuña, Vicenç; Petrović, Mira

2018-02-01

A mesocosm case study was conducted to gain understanding and practical knowledge on biofilm emerging contaminants biodegradation capacity under stressor and multiple stressor conditions. Two real life scenarios: I) biodegradation in a pristine intermittent stream experiencing acute pollution and II) biodegradation in a chronically polluted intermittent stream, were examined via a multifactorial experiment using an artificial stream facility. Stream biofilms were exposed to different water flow conditions i.e. permanent and intermittent water flow. Venlafaxine, a readily biodegradable pharmaceutical was used as a measure of biodegradation capacity while pollution was simulated by a mixture of four emerging contaminants (erythromycin, sulfisoxazole, diclofenac and imidacloprid in addition to venlafaxine) in environmentally relevant concentrations. Biodegradation kinetics monitored via LC-MS/MS was established, statistically evaluated, and used to link biodegradation with stress events. The results suggest that the effects of intermittent flow do not hinder and may even stimulate pristine biofilm biodegradation capacity. Chronic pollution completely reduced biodegradation in permanent water flow experimental treatments while no change in intermittent streams was observed. A combined effect of water flow conditions and emerging contaminants exposure on biodegradation was found. The decrease in biodegradation due to exposure to emerging contaminants is significantly greater in streams with permanent water flow suggesting that the short and medium term biodegradation capacity in intermittent systems may be preserved or even greater than in perennial streams. Copyright © 2017 Elsevier Ltd. All rights reserved.

Biodegradation of hydrocarbon mixtures in surface waters at environmentally relevant levels - Effect of inoculum origin on kinetics and sequence of degradation.

PubMed

Birch, Heidi; Hammershøj, Rikke; Comber, Mike; Mayer, Philipp

2017-10-01

Biodegradation is a dominant removal process for many organic pollutants, and biodegradation tests serve as tools for assessing their environmental fate within regulatory risk assessment. In simulation tests, the inoculum is not standardized, varying in microbial quantity and quality, thereby potentially impacting the observed biodegradation kinetics. In this study we investigated the effect of inoculum origin on the biodegradation kinetics of hydrocarbons for five inocula from surface waters varying in urbanization and thus expected pre-exposure to petroleum hydrocarbons. A new biodegradation method for testing mixtures of hydrophobic chemicals at trace concentrations was demonstrated: Aqueous solutions containing 9 hydrocarbons were generated by passive dosing and diluted with surface water resulting in test systems containing native microorganisms exposed to test substances at ng-μg/L levels. Automated Headspace Solid Phase Microextraction coupled to GC-MS was applied directly to these test systems to determine substrate depletion relative to abiotic controls. Lag phases were generally less than 8 days. First order rate constants were within one order of magnitude for each hydrocarbon in four of the five waters but lower in water from a rural lake. The sequence of degradation between the 9 hydrocarbons showed similar patterns in the five waters indicating the potential for using selected hydrocarbons for benchmarking between biodegradation tests. Degradation half-times were shorter than or within one order of magnitude of BioHCwin predictions for 8 of 9 hydrocarbons. These results showed that location choice is important for biodegradation kinetics and can provide a relevant input to aquatic exposure and fate models. Copyright © 2017 Elsevier Ltd. All rights reserved.

Bioremediation of Petroleum Hydrocarbon Contaminated Sites

DOE Office of Scientific and Technical Information (OSTI.GOV)

Fallgren, Paul

Bioremediation has been widely applied in the restoration of petroleum hydrocarbon-contaminated. Parameters that may affect the rate and efficiency of biodegradation include temperature, moisture, salinity, nutrient availability, microbial species, and type and concentration of contaminants. Other factors can also affect the success of the bioremediation treatment of contaminants, such as climatic conditions, soil type, soil permeability, contaminant distribution and concentration, and drainage. Western Research Institute in conjunction with TechLink Environmental, Inc. and the U.S. Department of Energy conducted laboratory studies to evaluate major parameters that contribute to the bioremediation of petroleum-contaminated drill cuttings using land farming and to develop amore » biotreatment cell to expedite biodegradation of hydrocarbons. Physical characteristics such as soil texture, hydraulic conductivity, and water retention were determined for the petroleum hydrocarbon contaminated soil. Soil texture was determined to be loamy sand to sand, and high hydraulic conductivity and low water retention was observed. Temperature appeared to have the greatest influence on biodegradation rates where high temperatures (>50 C) favored biodegradation. High nitrogen content in the form of ammonium enhanced biodegradation as well did the presence of water near field water holding capacity. Urea was not a good source of nitrogen and has detrimental effects for bioremediation for this site soil. Artificial sea water had little effect on biodegradation rates, but biodegradation rates decreased after increasing the concentrations of salts. Biotreatment cell (biocell) tests demonstrated hydrocarbon biodegradation can be enhanced substantially when utilizing a leachate recirculation design where a 72% reduction of hydrocarbon concentration was observed with a 72-h period at a treatment temperature of 50 C. Overall, this study demonstrates the investigation of the effects of environmental parameters on bioremediation is important in designing a bioremediation system to reduce petroleum hydrocarbon concentrations in impacted soils.« less

Biochemical interpretation of quantitative structure-activity relationships (QSAR) for biodegradation of N-heterocycles: a complementary approach to predict biodegradability.

PubMed

Philipp, Bodo; Hoff, Malte; Germa, Florence; Schink, Bernhard; Beimborn, Dieter; Mersch-Sundermann, Volker

2007-02-15

Prediction of the biodegradability of organic compounds is an ecologically desirable and economically feasible tool for estimating the environmental fate of chemicals. We combined quantitative structure-activity relationships (QSAR) with the systematic collection of biochemical knowledge to establish rules for the prediction of aerobic biodegradation of N-heterocycles. Validated biodegradation data of 194 N-heterocyclic compounds were analyzed using the MULTICASE-method which delivered two QSAR models based on 17 activating (OSAR 1) and on 16 inactivating molecular fragments (GSAR 2), which were statistically significantly linked to efficient or poor biodegradability, respectively. The percentages of correct classifications were over 99% for both models, and cross-validation resulted in 67.9% (GSAR 1) and 70.4% (OSAR 2) correct predictions. Biochemical interpretation of the activating and inactivating characteristics of the molecular fragments delivered plausible mechanistic interpretations and enabled us to establish the following biodegradation rules: (1) Target sites for amidohydrolases and for cytochrome P450 monooxygenases enhance biodegradation of nonaromatic N-heterocycles. (2) Target sites for molybdenum hydroxylases enhance biodegradation of aromatic N-heterocycles. (3) Target sites for hydratation by an urocanase-like mechanism enhance biodegradation of imidazoles. Our complementary approach represents a feasible strategy for generating concrete rules for the prediction of biodegradability of organic compounds.

Coupling UV-H2O2 to accelerate dimethyl phthalate (DMP) biodegradation and oxidation.

PubMed

Chen, Bin; Song, Jiaxiu; Yang, Lihui; Bai, Qi; Li, Rongjie; Zhang, Yongming; Rittmann, Bruce E

2015-11-01

Dimethyl phthalate (DMP), an important industrial raw material, is an endocrine disruptor of concern for human and environmental health. DMP exhibits slow biodegradation, and its coupled treatment by means of advanced oxidation may enhance its biotransformation and mineralization. We evaluated two ways of coupling UV-H2O2 advanced oxidation to biodegradation: sequential coupling and intimate coupling in an internal circulation baffled biofilm reactor (ICBBR). During sequential coupling, UV-H2O2 pretreatment generated carboxylic acids that depressed the pH, and subsequent biodegradation generated phthalic acid; both factors inhibited DMP biodegradation. During intimately coupled UV-H2O2 with biodegradation, carboxylic acids and phthalic acid (PA) did not accumulate, and the biodegradation rate was 13 % faster than with biodegradation alone and 78 % faster than with biodegradation after UV-H2O2 pretreatment. Similarly, DMP oxidation with intimate coupling increased by 5 and 39 %, respectively, compared with biodegradation alone and sequential coupling. The enhancement effects during intimate coupling can be attributed to the rapid catabolism of carboxylic acids, which generated intracellular electron carriers that directly accelerated di-oxygenation of PA and relieved the inhibition effect of PA and low pH. Thus, intimate coupling optimized the impacts of energy input from UV irradiation used together with biodegradation.

Biodegradation of Para Amino Acetanilide by Halomonas sp. TBZ3.

PubMed

Hajizadeh, Nader; Sefidi Heris, Youssof; Zununi Vahed, Sepideh; Vallipour, Javad; Hejazi, Mohammad Amin; Golabi, Sayyed Mahdi; Asadpour-Zeynali, Karim; Hejazi, Mohammad Saeid

2015-09-01

Aromatic compounds are known as a group of highly persistent environmental pollutants. Halomonas sp. TBZ3 was isolated from the highly salty Urmia Lake of Iran. In this study, characterization of a new Halomonas isolate called Halomonas sp. TBZ3 and its employment for biodegradation of para-amino acetanilide (PAA), as an aromatic environmental pollutant, is described. This study aimed to characterize the TBZ3 isolate and to elucidate its ability as a biodegradative agent that decomposes PAA. Primarily, DNA-DNA hybridization between TBZ3, Halomonas denitrificans DSM18045T and Halomonas saccharevitans LMG 23976T was carried out. Para-amino acetanilide biodegradation was assessed using spectrophotometry and confirmed by gas chromatography-mass spectroscopy (GC-MS). Parameters effective on biodegradation of PAA were optimized by the Response Surface Methodology (RSM). The DNA-DNA hybridization experiments between isolate TBZ3, H. denitrificans and H. saccharevitans revealed relatedness levels of 57% and 65%, respectively. According to GC-MS results, TBZ3 degrades PAA to benzene, hexyl butanoate, 3-methyl-1-heptanol and hexyl hexanoate. Temperature 32.92°C, pH 6.76, and salinity 14% are the optimum conditions for biodegradation with a confidence level of 95% (at level α = 0.05). According to our results, Halomonas sp. TBZ3 could be considered as a biological agent for bioremediation of PAA and possibly other similar aromatic compounds.

Biodegradation of Para Amino Acetanilide by Halomonas sp. TBZ3

PubMed Central

Hajizadeh, Nader; Sefidi Heris, Youssof; Zununi Vahed, Sepideh; Vallipour, Javad; Hejazi, Mohammad Amin; Golabi, Sayyed Mahdi; Asadpour-Zeynali, Karim; Hejazi, Mohammad Saeid

2015-01-01

Background: Aromatic compounds are known as a group of highly persistent environmental pollutants. Halomonas sp. TBZ3 was isolated from the highly salty Urmia Lake of Iran. In this study, characterization of a new Halomonas isolate called Halomonas sp. TBZ3 and its employment for biodegradation of para-amino acetanilide (PAA), as an aromatic environmental pollutant, is described. Objectives: This study aimed to characterize the TBZ3 isolate and to elucidate its ability as a biodegradative agent that decomposes PAA. Materials and Methods: Primarily, DNA-DNA hybridization between TBZ3, Halomonas denitrificans DSM18045T and Halomonas saccharevitans LMG 23976T was carried out. Para-amino acetanilide biodegradation was assessed using spectrophotometry and confirmed by gas chromatography-mass spectroscopy (GC-MS). Parameters effective on biodegradation of PAA were optimized by the Response Surface Methodology (RSM). Results: The DNA-DNA hybridization experiments between isolate TBZ3, H. denitrificans and H. saccharevitans revealed relatedness levels of 57% and 65%, respectively. According to GC-MS results, TBZ3 degrades PAA to benzene, hexyl butanoate, 3-methyl-1-heptanol and hexyl hexanoate. Temperature 32.92°C, pH 6.76, and salinity 14% are the optimum conditions for biodegradation with a confidence level of 95% (at level α = 0.05). Conclusions: According to our results, Halomonas sp. TBZ3 could be considered as a biological agent for bioremediation of PAA and possibly other similar aromatic compounds. PMID:26495103

Worldwide Emerging Environmental Issues Affecting the U.S. Military. December 2007 Report

DTIC Science & Technology

2007-12-01

was developed by researchers of Cornell University. The plastic is a modified form of polyhydroxybutyrate ( PHB ), a promising biodegradable plastic...produced from bacteria. The use of PHB has been limited because of its brittleness and unpredictable biodegradation rates. The new material, which is

Cylindrospermopsin Biodegradation Abilities of Aeromonas sp. Isolated from Rusałka Lake

PubMed Central

Dziga, Dariusz; Kokocinski, Mikolaj; Maksylewicz, Anna; Czaja-Prokop, Urszula; Barylski, Jakub

2016-01-01

The occurrence of the cyanobacterial toxin cylindrospermopsin (CYN) in freshwater reservoirs is a common phenomenon. However, the biodegradation of this toxin in environmental samples has been observed only occasionally. In this work the biodegradation ability of cylindrospermopsin was investigated based on isolates from lakes with previous cyanotoxin history. Bacterial strains were identified based on the 16S rDNA and rpoD gene comparison. CYN biodegradation was monitored using the HPLC method. The R6 strain identified as Aeromonas sp. was documented as being capable of CYN removal. This biodegradation was dependent on the pH and temperature. Additionally, the stimulation of the growth of the R6 strain in the presence of CYN was indicated. Our discovery supports the hypothesis that (in analogy to the well-known phenomenon of microcystin biodegradation) in lakes dominated by potential CYN-producing cyanobacteria, the processes of microbial utilization of this toxin may occur. PMID:26927173

Cylindrospermopsin Biodegradation Abilities of Aeromonas sp. Isolated from Rusałka Lake.

PubMed

Dziga, Dariusz; Kokocinski, Mikolaj; Maksylewicz, Anna; Czaja-Prokop, Urszula; Barylski, Jakub

2016-02-25

The occurrence of the cyanobacterial toxin cylindrospermopsin (CYN) in freshwater reservoirs is a common phenomenon. However, the biodegradation of this toxin in environmental samples has been observed only occasionally. In this work the biodegradation ability of cylindrospermopsin was investigated based on isolates from lakes with previous cyanotoxin history. Bacterial strains were identified based on the 16S rDNA and rpoD gene comparison. CYN biodegradation was monitored using the HPLC method. The R6 strain identified as Aeromonas sp. was documented as being capable of CYN removal. This biodegradation was dependent on the pH and temperature. Additionally, the stimulation of the growth of the R6 strain in the presence of CYN was indicated. Our discovery supports the hypothesis that (in analogy to the well-known phenomenon of microcystin biodegradation) in lakes dominated by potential CYN-producing cyanobacteria, the processes of microbial utilization of this toxin may occur.

Does bioavailability limit biodegradation? A comparison of hydrocarbon biodegradation and desorption rates in aged soils.

PubMed

Huesemann, Michael H; Hausmann, Tom S; Fortman, Tim J

2004-08-01

In order to determine whether bioavailability limits the biodegradability of petroleum hydrocarbons in aged soils, both the biodegradation and abiotic desorption rates of PAHs and n-alkanes were measured at various time points in six different aged soils undergoing slurry bioremediation treatment. Alkane biodegradation rates were always much greater than the respective desorption rates, indicating that these saturated hydrocarbons apparently do not need to be dissolved into the aqueous phase prior to metabolism by soil microorganisms. The biodegradation of PAHs was generally not mass-transfer rate limited during the initial phase, while it often became so at the end of the treatment period when biodegradation rates equaled abiotic desorption rates. However, in all cases where PAH biodegradation was not observed or PAH removal temporarily stalled, bioavailability limitations were not deemed responsible for this recalcitrance since these PAHs desorbed rapidly from the soil into the aqueous phase. Consequently, aged PAHs that are often thought to be recalcitrant due to bioavailability limitations may not be so and therefore may pose a greater risk to environmental receptors than previously thought.

Does Bioavailability Limit Biodegradability? A Comparison of Hydrocarbon Biodegradation and Desorption Rates in Aged Soils

DOE Office of Scientific and Technical Information (OSTI.GOV)

Huesemann, Michael H.; Hausmann, Tom S.; Fortman, Timothy J.

In order to determine whether bioavailability limits the biodegradability of petroleum hydrocarbons in aged soils, both the biodegradation and abiotic desorption rates of PAHs and n-alkanes were measured at various time points in six different aged soils undergoing slurry bioremediation treatment. Alkane biodegradation rates were always much greater than the respective desorption rates, indicating that these saturated hydrocarbons do not need to be transferred into the aqueous phase prior to metabolism by soil microorganisms. The biodegradation of PAHs was generally not mass-transfer rate limited during the initial phase, while it often became so at the end of the treatment periodmore » when biodegradation rates equaled abiotic desorption rates. However, in all cases where PAH biodegradation was not observed or PAH removal temporarily stalled, bioavailability limitations were not deemed responsible for this recalcitrance since these PAHs desorbed rapidly from the soil into the aqueous phase. Consequently, aged PAHs that are often thought to be recalcitrant due to bioavailability limitations may not be so and therefore may pose a greater risk to environmental receptors than previously thought.« less

EFFECT OF AMOUNT OF CRUDE OIL ON EXTENT OF ITS BIODEGRADATION IN OPEN WATER- AND SANDY BEACH-LABORATORY SIMULATIONS

EPA Science Inventory

Bioremediation of marine oil spills, a technology using hydrocarbon-degrading and emulsifying capabilities of microorganisms, has many unexplored limitations, and among them is degree of environmental oil contamination. We examined the biodegradation of varying amounts of artifi...

Advances in Biodegradation of Multiple Volatile Organic Compounds

NASA Astrophysics Data System (ADS)

Zhang, M.; Yoshikawa, M.

2017-12-01

Bioremediation of soil and groundwater containing multiple contaminants remains a challenge in environmental science and engineering because complete biodegradation of all components is necessary but very difficult to accomplish in practice. This presentation provides a brief overview on advances in biodegradation of multiple volatile organic compounds (VOCs) including chlorinated ethylenes, benzene, toluene and dichloromethane (DCM). Case studies on aerobic biodegradation of benzene, toluene and DCM, and integrated anaerobic-aerobic biodegradation of 7 contaminants, specifically, tetrachloroethylene (PCE), trichloroethylene (TCE), cis-dichloroethylene (cis-DCE), vinyl chloride (VC), DCM, benzene and toluene will be provided. Recent findings based on systematic laboratory experiments indicated that aerobic toluene degradation can be enhanced by co-existence of benzene. Propioniferax, not a known benzene, toluene and DCM degrader can be a key microorganism that involves in biodegradation when the three contaminants co-exist. Integrated anaerobic-aerobic biodegradation is capable of completely degrading the seven VOCs with initial concentrations less than 30 mg/L. Dehalococcoides sp., generally considered sensitive to oxygen, can survive aerobic conditions for at least 28 days, and can be activated during the subsequent anaerobic biodegradation. This presentation may provide a systematic information about biodegradation of multiple VOCs, and a scientific basis for the complete bioremediation of multiple contaminants in situ.

Rhamnolipid-enhanced aerobic biodegradation of triclosan (TCS) by indigenous microorganisms in water-sediment systems.

PubMed

Guo, Qian; Yan, Jia; Wen, Junjie; Hu, Yongyou; Chen, Yuanbo; Wu, Wenjin

2016-11-15

Bioremediation of triclosan (TCS) is a challenge because of its low bioavailability, persistence in the environment and recalcitrance to remediation efforts. Rhamnolipid (RL) was used to enhance TCS biodegradation by indigenous microbes in an aerobic water-sediment system. However, knowledge of the effects of TCS on the bacterial community and environmental factors in an RL-enhanced, TCS-degrading system are lacking. Therefore, in this study, the influence of environmental factors on RL-enhanced biodegradation of TCS was investigated by single factor experiments, and shifts in aerobic TCS-degrading bacterial populations, with and without RL, were analyzed by high-throughput sequencing technology. The results showed that aerobic biodegradation of TCS was significantly promoted by the addition of RL. Environmental conditions, which included RL addition (0.125-0.5g/L), medium concentrations of TCS (<90μg/g), water disturbance, elevated temperature, ionic strength (0.001-0.1mol/L NaCl) and weak alkaline environments (pH8-9), were monitored. High concentrations of TCS had a remarkable influence on the bacterial community structure, and this influence on the distribution proportion of the main microorganisms was strengthened by RL addition. Alpha-proteobacteria (e.g., Sphingomonadaceae and Caulobacteraceae) might be resistant to TCS or even capable of TCS biodegradation, while Sphingobacteria, Beta- and Delta-proteobacteria were sensitive to TCS toxicity. This research provides ecological information on the degradation efficiency and bacterial community stability in RL-enhanced bioremediation of TCS-polluted aquatic environments. Copyright © 2016 Elsevier B.V. All rights reserved.

Environmental fate and behavior of acesulfame in laboratory experiments.

PubMed

Storck, Florian R; Skark, Christian; Remmler, Frank; Brauch, Heinz-Jürgen

2016-12-01

Acesulfame is a widely used artificial sweetener. It can be discharged into surface water by domestic wastewater due to its incomplete retention during wastewater treatment. Concentrations may reach up to 10 μg/L for smaller rivers. State-of-the-art analysis allows the determination of acesulfame traces (0.01 μg/L) and thus a potential tracking of the presence of wastewater in riverbank filtrate. To evaluate the behavior of acesulfame in the aquatic environment, biodegradation and sorption of acesulfame were tested. Batch experiments yielded low sorption for several soils (estimated solid-water distribution coefficient of acesulfame <0.1 L/kg). Biodegradation in a fixed-bed reactor was not observed at environmental concentrations of 9 μg/L in aqueous compost and soil extract (observation period 56 days). Only in diluted effluent of a wastewater treatment plant did biodegradation start, after 17 days of operation, and acesulfame completely fade, within 28 days. Flow-through column experiments indicated conservative behavior of acesulfame (recovery >83%) and long-term observations at different concentration levels yielded no biodegradation. Overall, laboratory experiments demonstrated a conservative behavior of acesulfame under conditions typical for riverbank filtration. However, there are hints for certain settings which favor an adaptation of the microbial community and facilitate a rapid biodegradation of acesulfame.

Effects of secondary carbon supplement on biofilm-mediated biodegradation of naphthalene by mutated naphthalene 1, 2-dioxygenase encoded by Pseudomonas putida strain KD9.

PubMed

Dutta, Kunal; Shityakov, Sergey; Khalifa, Ibrahim; Mal, Arpan; Moulik, Satya Priya; Panda, Amiya Kumar; Ghosh, Chandradipa

2018-05-18

Polycyclic aromatic hydrocarbons (PAHs) belong to a diverse group of environmental pollutants distributed ubiquitously in the environment. The carcinogenic properties of PAHs are the main causes of harm to human health. The green technology, biodegradation have become convenient options to address the environmental pollution. In this study, we analyzed the biodegradation potential of naphthalene with secondary carbon supplements (SCSs) in carbon deficient media (CSM) by Pseudomonas putida strain KD9 isolated from oil refinerary waste. The rigid-flexible molecular docking method revealed that the mutated naphthalene 1,2-dioxygenase had lower affinity for naphthalene than that found in wild type strain. Moreover, analytical methods (HPLC, qRT-PCR) and soft agar chemotaxis suggest sucrose (0.5 wt%) to be the best chemo-attractant and it unequivocally caused enhanced biodegradation of naphthalene (500 mg L -1 ) in both biofilm-mediated and shake-flask biodegradation methods. In addition, the morphological analysis detected from microscopy clearly showed KD9 to change its size and shape (rod to pointed) during biodegradation of naphthalene in CSM as sole source of carbon and energy. The forward versus side light scatter plot of the singlet cells obtained from flow cytometry suggests smaller cell size in CSM and lower florescence intensity of the total DNA content of cells. This study concludes that sucrose may be used as potential bio-stimulation agent. Copyright © 2018 Elsevier B.V. All rights reserved.

Biodegradable materials for multilayer transient printed circuit boards.

PubMed

Huang, Xian; Liu, Yuhao; Hwang, Suk-Won; Kang, Seung-Kyun; Patnaik, Dwipayan; Cortes, Jonathan Fajardo; Rogers, John A

2014-11-19

Biodegradable printed circuit boards based on water-soluble materials are demonstrated. These systems can dissolve in water within 10 mins to yield end-products that are environmentally safe. These and related approaches have the potential to reduce hazardous waste streams associated with electronics disposal. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Regeneration of Three-Way Automobile Catalysts using Biodegradable Metal Chelating Agent – S, S-Ethylenediamine Disuccinic Acid (S, S-EDDS)

EPA Science Inventory

Regeneration of the activity of three-way catalytic converters (TWCs) was tested for the first time using a biodegradable metal chelating agent (S, S. Ethylenediamine disuccinic acid (S, S-EDDS). The efficiency of this novel environmentally friendly solvent in removing various c...

High-performance green flexible electronics based on biodegradable cellulose nanofibril paper

Treesearch

Yei Hwan Jung; Tzu-Hsuan Chang; Huilong Zhang; Chunhua Yao; Qifeng Zheng; Vina W. Yang; Hongyi Mi; Munho Kim; Sang June Cho; Dong-Wook Park; Hao Jiang; Juhwan Lee; Yijie Qiu; Weidong Zhou; Zhiyong Cai; Shaoqin Gong; Zhenqiang Ma

2015-01-01

Today’s consumer electronics, such as cell phones, tablets and other portable electronic devices, are typically made of non-renewable, non-biodegradable, and sometimes potentially toxic (for example, gallium arsenide) materials. These consumer electronics are frequently upgraded or discarded, leading to serious environmental contamination. Thus, electronic systems...

ADDING GLYCERINE TO ECO-FRIENDLY GOLF TEES TO ACCELERATE BIODEGRADABILITY AND IMPROVE FABRICATION

EPA Science Inventory

It is expected that a suitable combination of DDGS and glycerine with PLA as well as a corresponding blend with corn-starch will be found. These blends will be applicable to a commercial, biodegradable golf tee with superior environmental properties, compared to what is on the...

Biodegradation of dispersed oil in Arctic seawater at -1°C.

PubMed

McFarlin, Kelly M; Prince, Roger C; Perkins, Robert; Leigh, Mary Beth

2014-01-01

As offshore oil and gas exploration expands in the Arctic, it is important to expand the scientific understanding of arctic ecology and environmental impact to mitigate operational risks. Understanding the fate of oil in arctic seawater is a key factor for consideration. Here we report the chemical loss due to the biodegradation of Alaska North Slope (ANS) crude oil that would occur in the water column following the successful dispersion of a surface oil slick. Primary biodegradation and mineralization were measured in mesocosms containing Arctic seawater collected from the Chukchi Sea, Alaska, incubated at -1°C. Indigenous microorganisms degraded both fresh and weathered oil, in both the presence and absence of Corexit 9500, with oil losses ranging from 46-61% and up to 11% mineralization over 60 days. When tested alone, 14% of 50 ppm Corexit 9500 was mineralized within 60 days. Our study reveals that microorganisms indigenous to Arctic seawater are capable of performing extensive biodegradation of chemically and physically dispersed oil at an environmentally relevant temperature (-1°C) without any additional nutrients.

The influence of surfactants on cell surface properties of Aeromonas hydrophila during diesel oil biodegradation.

PubMed

Kaczorek, E; Urbanowicz, M; Olszanowski, A

2010-11-01

In this study the capacity of the newly isolated environmental strain Aeromonas hydrophila was evaluated. The influence of three surfactants: rhamnolipides, saponins and Triton X-100 on cell surface properties of the A. hydrophila environmental strain and the biodegradation process of diesel oil was studied. The surface activities in water, a mineral salts medium and in the biological system of all considered surfactants were estimated by means of equilibrium surface tension experiments. The obtained results indicated that critical micellar concentration in the biological system is twice higher for saponins and Triton X-100, and three times higher for rhamnolipides. Our results indicated also, that cell surface hydrophobicity (CSH) of bacteria is correlated with carbon sources in broth medium. The mechanism of surfactant action seems to be dependent on the type and concentration of surfactant used in the studies. The best effect of saponins on diesel oil biodegradation was observed using the A. hydrophila strain, diesel oil biodegradation after 21 days was 78%. Copyright (c) 2010 Elsevier B.V. All rights reserved.

Effects of different culture media on biodegradation of triclosan by Rhodotorula mucilaginosa and Penicillium sp.

PubMed

Ertit Taştan, Burcu; Özdemir, Caner; Tekinay, Turgay

Triclosan is an antimicrobial agent and a persistent pollutant. The biodegradation of triclosan is dependent on many variables including the biodegradation organism and the environmental conditions. Here, we evaluated the triclosan degradation potential of two fungi strains, Rhodotorula mucilaginosa and Penicillium sp., and the rate of its turnover to 2,4-dichlorophenol (2,4-DCP). Both of these strains showed less susceptibility to triclosan when grown in minimal salt medium. In order to further evaluate the effects of environmental conditions on triclosan degradation, three different culture conditions including original thermal power plant wastewater, T6 nutrimedia and ammonium mineral salts medium were used. The maximum triclosan degradation yield was 48% for R. mucilaginosa and 82% for Penicillium sp. at 2.7 mg/L triclosan concentration. Biodegradation experiments revealed that Penicillium sp. was more tolerant to triclosan. Scanning electron microscopy micrographs also showed the morphological changes of fungus when cells were treated with triclosan. Overall, these fungi strains could be used as effective microorganisms in active uptake (degradation) and passive uptake (sorption) of triclosan and their efficiency can be increased by optimizing the culture conditions.

Biodegradation of Dispersed Oil in Arctic Seawater at -1°C

PubMed Central

McFarlin, Kelly M.; Prince, Roger C.; Perkins, Robert; Leigh, Mary Beth

2014-01-01

As offshore oil and gas exploration expands in the Arctic, it is important to expand the scientific understanding of arctic ecology and environmental impact to mitigate operational risks. Understanding the fate of oil in arctic seawater is a key factor for consideration. Here we report the chemical loss due to the biodegradation of Alaska North Slope (ANS) crude oil that would occur in the water column following the successful dispersion of a surface oil slick. Primary biodegradation and mineralization were measured in mesocosms containing Arctic seawater collected from the Chukchi Sea, Alaska, incubated at −1°C. Indigenous microorganisms degraded both fresh and weathered oil, in both the presence and absence of Corexit 9500, with oil losses ranging from 46−61% and up to 11% mineralization over 60 days. When tested alone, 14% of 50 ppm Corexit 9500 was mineralized within 60 days. Our study reveals that microorganisms indigenous to Arctic seawater are capable of performing extensive biodegradation of chemically and physically dispersed oil at an environmentally relevant temperature (−1°C) without any additional nutrients. PMID:24416211

A model framework to describe growth-linked biodegradation of trace-level pollutants in the presence of coincidental carbon substrates and microbes.

PubMed

Liu, Li; Helbling, Damian E; Kohler, Hans-Peter E; Smets, Barth F

2014-11-18

Pollutants such as pesticides and their degradation products occur ubiquitously in natural aquatic environments at trace concentrations (μg L(-1) and lower). Microbial biodegradation processes have long been known to contribute to the attenuation of pesticides in contaminated environments. However, challenges remain in developing engineered remediation strategies for pesticide-contaminated environments because the fundamental processes that regulate growth-linked biodegradation of pesticides in natural environments remain poorly understood. In this research, we developed a model framework to describe growth-linked biodegradation of pesticides at trace concentrations. We used experimental data reported in the literature or novel simulations to explore three fundamental kinetic processes in isolation. We then combine these kinetic processes into a unified model framework. The three kinetic processes described were: the growth-linked biodegradation of micropollutant at environmentally relevant concentrations; the effect of coincidental assimilable organic carbon substrates; and the effect of coincidental microbes that compete for assimilable organic carbon substrates. We used Monod kinetic models to describe substrate utilization and microbial growth rates for specific pesticide and degrader pairs. We then extended the model to include terms for utilization of assimilable organic carbon substrates by the specific degrader and coincidental microbes, growth on assimilable organic carbon substrates by the specific degrader and coincidental microbes, and endogenous metabolism. The proposed model framework enables interpretation and description of a range of experimental observations on micropollutant biodegradation. The model provides a useful tool to identify environmental conditions with respect to the occurrence of assimilable organic carbon and coincidental microbes that may result in enhanced or reduced micropollutant biodegradation.

Comparative study on the biodegradability of morpholinium herbicidal ionic liquids.

PubMed

Ławniczak, Łukasz; Materna, Katarzyna; Framski, Grzegorz; Szulc, Alicja; Syguda, Anna

2015-07-01

This study focused on evaluating the toxicity as well as primary and ultimate biodegradability of morpholinium herbicidal ionic liquids (HILs), which incorporated MCPA, MCPP, 2,4-D or Dicamba anions. The studied HILs were also subjected to determination of surface active properties in order to assess their influence on toxicity and biodegradability. The study was carried out with microbiota isolated from different environmental niches: sediments from river channel, garden soil, drainage trench collecting agricultural runoff stream, agricultural soil and municipal waste repository. The obtained results revealed that resistance to toxicity and biodegradation efficiency of the microbiota increased in the following order: microbiota from the waste repository > microbiota from agricultural soil ≈ microbiota from an agricultural runoff stream > microbiota from garden soil > microbiota from the river sludge. It was observed that the toxicity of HILs increased with the hydrophobicity of the cation, however the influence of the anion was more notable. The highest toxicity was observed when MCPA was used as the anion (EC50 values ranging from 60 to 190 mg L(-1)). The results of ultimate biodegradation tests indicated that only HILs with 2,4-D as the anion were mineralized to some extent, with slightly higher values for HILs with the 4-decyl-4-ethylmorpholinium cation (10-31 %) compared to HILs with the 4,4-didecylmorpholinium cation (9-20 %). Overall, the cations were more susceptible (41-94 %) to primary biodegradation compared to anions (0-61 %). The obtained results suggested that the surface active properties of the studied HILs may influence their toxicity and biodegradability by bacteria in different environmental niches.

Antimicrobial activity of biodegradable polysaccharide and protein-based films containing active agents.

PubMed

Kuorwel, Kuorwel K; Cran, Marlene J; Sonneveld, Kees; Miltz, Joseph; Bigger, Stephen W

2011-04-01

Significant interest has emerged in the introduction of food packaging materials manufactured from biodegradable polymers that have the potential to reduce the environmental impacts associated with conventional packaging materials. Current technologies in active packaging enable effective antimicrobial (AM) packaging films to be prepared from biodegradable materials that have been modified and/or blended with different compatible materials and/or plasticisers. A wide range of AM films prepared from modified biodegradable materials have the potential to be used for packaging of various food products. This review examines biodegradable polymers derived from polysaccharides and protein-based materials for their potential use in packaging systems designed for the protection of food products from microbial contamination. A comprehensive table that systematically analyses and categorizes much of the current literature in this area is included in the review.

Environmental impacts the of production and use of biodiesel.

PubMed

Živković, Snežana; Veljković, Milan

2018-01-01

Biodiesel as renewable, environmental friendly, less toxic, and biodegradable is an attractive alternative to fossil fuels and is produced mainly from vegetable oils and animal fats. It is expected, globally, that the use of renewable biofuels, in general, will increase rapidly in the near future. The growing biodiesel production and usage have encouraged assessment of its impact on the environment. The present paper reviews various aspects of biodiesel production using commercial processing technology and biodiesel use through evaluation and analysis of the studies concerning environmental impacts of biodiesel. As a general conclusion, it can be said that biodiesel has the potential to offer a series of perceived benefits such as political, economical, and agricultural, as well as environmental (due to its biodegradability, less toxicity, renewability) and health (greenhouse gas-saving, less harmful exhaust emissions).

Biodegradation tests of mercaptocarboxylic acids, their esters, related divalent sulfur compounds and mercaptans.

PubMed

Rücker, Christoph; Mahmoud, Waleed M M; Schwartz, Dirk; Kümmerer, Klaus

2018-04-17

Mercaptocarboxylic acids and their esters, a class of difunctional compounds bearing both a mercapto and a carboxylic acid or ester functional group, are industrial chemicals of potential environmental concern. Biodegradation of such compounds was systematically investigated here, both by literature search and by experiments (Closed Bottle Test OECD 301D and Manometric Respirometry Test OECD 301F). These compounds were found either readily biodegradable or at least biodegradable to a significant extent. Some related compounds of divalent sulfur were tested for comparison (mercaptans, sulfides, disulfides). For the two relevant monofunctional compound classes, carboxylic acids/esters and mercaptans, literature data were compiled, and by comparison with structurally similar compounds without these functional groups, the influence of COOH/COOR' and SH groups on biodegradability was evaluated. Thereby, an existing rule of thumb for biodegradation of carboxylic acids/esters was supported by experimental data, and a rule of thumb could be formulated for mercaptans. Concurrent to biodegradation, abiotic processes were observed in the experiments, rapid oxidative formation of disulfides (dimerisation of monomercaptans and cyclisation of dimercaptans) and hydrolysis of esters. Some problems that compromise the reproducibility of biodegradation test results were discussed.

Comparison of PAH Biodegradation and Desorption Kinetics During Bioremediation of Aged Petroleum Hydrocarbon Contaminated Soils

DOE Office of Scientific and Technical Information (OSTI.GOV)

Huesemann, Michael H.; Hausmann, Tom S.; Fortman, Timothy J.

It is commonly assumed that mass-transfer limitations are the cause for slow and incomplete biodegradation of PAHs in aged soils. In order to test this hypothesis, the biodegradation rate and the abiotic release rate were measured and compared for selected PAHs in three different soils. It was found that PAH biodegradation was not mass-transfer limited during slurry bioremediation of an aged loamy soil. By contrast, PAH biodegradation rates were much larger than abiotic release rates in kaolinite clay indicating that sorbed-phase PAHs can apparently be biodegraded directly from mineral surfaces without prior desorption or dissolution into the aqueous phase. Amore » comparison of PAH biodegradation rates and abiotic release rates at termination of the slurry bioremediation treatment revealed that abiotic release rates are much larger than the respective biodegradation rates. In addition, it was found that the number of hydrocarbon degraders decreased by four orders of magnitude during the bioremediation treatment. It can therefore be concluded that the slow and incomplete biodegradation of PAHs is not caused by mass-transfer limitations but rather by microbial factors. Consequently, the residual PAHs that remain after extensive bioremediation treatment are still bioavailable and for that reason could pose a greater risk to environmental receptors than previously thought.« less

Assessing Bacillus subtilis biosurfactant effects on the biodegradation of petroleum products.

PubMed

Montagnolli, Renato Nallin; Lopes, Paulo Renato Matos; Bidoia, Ederio Dino

2015-01-01

Microbial pollutant removal capabilities can be determined and exploited to accomplish bioremediation of hydrocarbon-polluted environments. Thus, increasing knowledge on environmental behavior of different petroleum products can lead to better bioremediation strategies. Biodegradation can be enhanced by adding biosurfactants to hydrocarbon-degrading microorganism consortia. This work aimed to improve petroleum products biodegradation by using a biosurfactant produced by Bacillus subtilis. The produced biosurfactant was added to biodegradation assays containing crude oil, diesel, and kerosene. Biodegradation was monitored by a respirometric technique capable of evaluating CO₂ production in an aerobic simulated wastewater environment. The biosurfactant yielded optimal surface tension reduction (30.9 mN m(-1)) and emulsification results (46.90% with kerosene). Biodegradation successfully occurred and different profiles were observed for each substance. Precise mathematical modeling of biosurfactant effects on petroleum degradation profile was designed, hence allowing long-term kinetics prediction. Assays containing biosurfactant yielded a higher overall CO₂ output. Higher emulsification and an enhanced CO2 production dataset on assays containing biosurfactants was observed, especially in crude oil and kerosene.

Biodegradable Polymeric Materials in Degradable Electronic Devices

PubMed Central

2018-01-01

Biodegradable electronics have great potential to reduce the environmental footprint of devices and enable advanced health monitoring and therapeutic technologies. Complex biodegradable electronics require biodegradable substrates, insulators, conductors, and semiconductors, all of which comprise the fundamental building blocks of devices. This review will survey recent trends in the strategies used to fabricate biodegradable forms of each of these components. Polymers that can disintegrate without full chemical breakdown (type I), as well as those that can be recycled into monomeric and oligomeric building blocks (type II), will be discussed. Type I degradation is typically achieved with engineering and material science based strategies, whereas type II degradation often requires deliberate synthetic approaches. Notably, unconventional degradable linkages capable of maintaining long-range conjugation have been relatively unexplored, yet may enable fully biodegradable conductors and semiconductors with uncompromised electrical properties. While substantial progress has been made in developing degradable device components, the electrical and mechanical properties of these materials must be improved before fully degradable complex electronics can be realized. PMID:29632879

Retardation of biodegradation of linear alkyl benzene sulphonate by a sublethal concentration of mercuric chloride

DOE Office of Scientific and Technical Information (OSTI.GOV)

Misra, V.; Pandey, S.D.; Viswanathan, P.N.

1991-10-01

Environmental xenobiotics are usually classified into persistent and biodegradable ones. However, this may not be universally true, since biochemical capacity of ecosystems species may vary with species diversity and versatility. This may differ in different locations decided by geoclimatic factors. Prolonged exposure of organisms causing primary degradation to the toxic xenobiotics may lead to metabolic adaptation to survive the chemical stress. Also under multiple toxicant stress, the normal biodegrading capacity may be impaired by the effect of one toxicant on the organisms per se or on the enzymes causing degradation. If such inhibition of biodegradation occurs in ecosystems, even normallymore » biodegradable chemicals may tend to accumulate. To test this view, model experiments were conducted with LAS (Linear alkyl benzene sulphonate) a biodegradable surfactant and mercuric chloride. Since the purpose of the study was to test the degradation under natural conditions, no attempt was made to identify the micro-organisms involved.« less

Adsorption and biodegradation of antidiabetic pharmaceuticals in soils.

PubMed

Mrozik, Wojciech; Stefańska, Justyna

2014-01-01

Pharmaceuticals are emerging contaminants in the natural environment. Most studies of the environmental fate of these chemicals focus on their behavior in wastewater treatment processes and in sewage sludge. Little is known about their behavior in soils. In this study adsorption and biodegradation of four antidiabetic pharmaceuticals - glimepiride, glibenclamide, gliclazide and metformin - were examined in three natural soils. The sorption of sulfonylurea derivatives was high (higher than sulfonylurea herbicides for example), whereas metformin showed high mobility. Desorption rates were highest for metformin. Sorption isotherms in two of three soils fitted best to the Freundlich model. Despite their high affinity to for soil surfaces, biodegradation studies revealed that transformation of the drugs occurred. Biodegradation results were described by pseudo-first order kinetics with half-life values from 5 to over 120 d (under aerobic conditions) and indicate that none of the tested drugs can be classified as quickly biodegradable. Biodegradation under anoxic conditions was much slower; often degrading by less than 50% during time of the experiment. Copyright © 2013 Elsevier Ltd. All rights reserved.

A direct comparison of U.S. Environmental Protection Agency's method 304B and batch tests for determining activated-sludge biodegradation rate constants for volatile organic compounds

DOE Office of Scientific and Technical Information (OSTI.GOV)

Cano, M.L.; Wilcox, M.E.; Compernolle, R. van

Biodegradation rate constants for volatile organic compounds (VOCs) in activated-sludge systems are needed to quantify emissions. One current US environmental Protection Agency method for determining a biodegradation rate constant is Method 304B. In this approach, a specific activated-sludge unit is simulated by a continuous biological treatment system with a sealed headspace. Batch experiments, however, can be alternatives to Method 304B. Two of these batch methods are the batch test that uses oxygen addition (BOX) and the serum bottle test (SBT). In this study, Method 304B was directly compared to BOX and SBT experiments. A pilot-scale laboratory reactor was constructed tomore » serve as the Method 304B unit. Biomass from the unit was also used to conduct BOX and modified SBT experiments (modification involved use of a sealed draft-tube reactor with a headspace recirculation pump instead of a serum bottle) for 1,2-dichloroethane, diisopropyl ether, methyl tertiary butyl ether, and toluene. Three experimental runs--each consisting of one Method 304B experiment, one BOX experiment, and one modified SBT experiment--were completed. The BOX and SBT data for each run were analyzed using a Monod model, and best-fit biodegradation kinetic parameters were determined for each experiment, including a first-order biodegradation rate constant (K{sub 1}). Experimental results suggest that for readily biodegradable VOCs the two batch techniques can provide improved means of determining biodegradation rate constants compared with Method 304B. In particular, these batch techniques avoid the Method 304B problem associated with steady-state effluent concentrations below analytical detection limits. However, experimental results also suggest that the two batch techniques should not be used to determine biodegradation rate constants for slowly degraded VOCs (i.e., K{sub 1} {lt} 0.1 L/g VSS-h).« less

An environmentally benign antimicrobial nanoparticle based ...

EPA Pesticide Factsheets

Silver nanoparticles have antibacterial properties but their use has been a cause for concern because they persist in the environment. Here we show that lignin nanoparticles infused with silver ions and coated with a cationic polyelectrolyte layer form a biodegradable and green alternative to silver nanoparticles. The polyelectrolyte layer promotes the adhesion of the particles to bacterial cell membranes and together with silver ions can kill a broad spectrum of bacteria, including Escherichia coli, Pseudomonas aeruginosa and quaternary-amine-resistant Ralstonia sp. Ion depletion studies showed that the bioactivity of these nanoparticles is time-limited because of the desorption of silver ions. High-throughput bioactivity screening did not reveal increased toxicity of the particles when compared to an equivalent mass of metallic silver nanoparticles or silver nitrate solution. Our results demonstrate that the application of green chemistry principles may allow the synthesis of nanoparticles with biodegradable cores that have higher antimicrobial activity and smaller environmental impact than metallic silver nanoparticles. Our results demonstrate that the application of green chemistry principles may allow the synthesis of nanoparticles with biodegradable cores that have higher antimicrobial activity and smaller environmental impact than metallic silver nanoparticles

Coatings and Biodegradable and Bioasorbable Films

DTIC Science & Technology

2006-12-28

linseed oil and soy oil VOMMs were designed and synthesized including linseed acrylate monomer (LiAM), soy acrylate monomer (SAM), soy amide acrylate...the plasticizing effects of vegetable oil macromonomers as incorporated into emulsion polymers for efficient almost zero VOC film formation and the...Environmentally friendly coatings, Topside Navy Haze Gray, Vegetable Oil Macromonomer, Low VOC, Biodegradable Food Packaging, Polyester-Polyurethanes

Enantioselective degradation of ofloxacin and levofloxacin by the bacterial strains Labrys portucalensis F11 and Rhodococcus sp. FP1.

PubMed

Maia, Alexandra S; Tiritan, Maria Elizabeth; Castro, Paula M L

2018-07-15

Fluoroquinolones are a class of antibiotics widely prescribed in both human and veterinary medicine of high environmental concern and characterized as environmental micropollutants due to their ecotoxicity and persistence and antibacterial resistance potential. Ofloxacin and levofloxacin are chiral fluoroquinolones commercialized as racemate and in enantiomerically pure form, respectively. Since the pharmacological properties and toxicity of the enantiomers may be very different, understanding the stereochemistry of these compounds should be a priority in environmental monitoring. This work presents the biodegradation of racemic ofloxacin and its (S)-enantiomer levofloxacin by the bacterial strains Labrys portucalensis F11 and Rhodococcus sp. FP1 at a laboratory-scale microcosm following the removal and the behavior of the enantiomers. Strain F11 could degrade both antibiotics almost completely when acetate was supplied regularly to the cultures. Enrichment of the (R)-enantiomer was observed in FP1 and F11 cultures supplied with ofloxacin. Racemization was observed in the biodegradation of the pure (S)-ofloxacin (levofloxacin) by strain F11, which was confirmed by liquid chromatography - exact mass spectrometry. Biodegradation of ofloxacin at 450 µg L -1 by both bacterial strains expressed good linear fits (R 2 > 0.98) according to the Rayleigh equation. The enantiomeric enrichment factors were comprised between - 22.5% to - 9.1%, and - 18.7% to - 9.0% in the biodegradation of ofloxacin by strains F11 and FP1, respectively, with no significant differences for the two bacteria under the same conditions. This is the first time that enantioselective biodegradation of ofloxacin and levofloxacin by single bacteria is reported. Copyright © 2018 Elsevier Inc. All rights reserved.

Revealing potential functions of VBNC bacteria in polycyclic aromatic hydrocarbons biodegradation.

PubMed

Su, X M; Bamba, A M; Zhang, S; Zhang, Y G; Hashmi, M Z; Lin, H J; Ding, L X

2018-04-01

The bioremediation of polycyclic aromatic hydrocarbon (PAH)-contaminated sites is not running smoothly, because of the lower activity of PAH-degrading bacteria in actual bioremediation applications. The phenomenon of "viable but nonculturable" (VBNC) state may be a main limiting factor for their poor biodegradation capabilities of PAHs. Due to their abilities of entering into the VBNC state, most of bacterial populations with PAH-degradation potential remain unculturable. Resuscitation of VBNC bacteria will enhance the degradation capability of indigenous bacteria which will eventually obtain their better capabilities in environmental bioremediation. Although evidences have been presented indicating that resuscitation of VBNC bacteria in polychlorinated biphenyl (PCB)-contaminated environments not only significantly enhanced PCB degradation, but also obtained novel highly efficient PCB-degrading bacteria, scanty information is available on the VBNC bacteria in PAH-contaminated sites. VBNC bacteria, as a vast majority of potential microbial resource could be the repository of novel highly efficient PAH-biodegraders. Therefore, studies need to be done on resuscitation of VBNC bacteria to overcome key bottlenecks in bioremediation of PAH-contaminated sites. This mini-review provides a new insight into the potential functions of VBNC bacteria in PAHs biodegradation. As the vast majority microbial resource, viable but nonculturable (VBNC) bacteria, which showed their potential functions in polycyclic aromatic hydrocarbons (PAHs) biodegradation, can be of great significance in environmental bioremediation. It is therefore important to resuscitate VBNC bacteria for their better capabilities. Meanwhile, preventing the indigenous functional community from entering into the VBNC state will also maintain the high activity of PAH-degrading bacteria in actual bioremediation applications. Undoubtedly, much more work needs to be done to reveal indigenous micro-organisms in the VBNC state from the perspective of environmental functions. © 2018 The Society for Applied Microbiology.

Bioremediation of oil spills by whale microbes. Final report, 1994-1995

DOE Office of Scientific and Technical Information (OSTI.GOV)

Craig, A.M.; Wachenheim, D.

1995-06-01

Baleen whale forestomach anaerobic microbes were studied for their ability to detoxify recalcitrant environmental pollutants; these include components of crude oil and some chlorinated aromatic compounds which are constituents of oil spills not biodegraded by aerobic microbes. In this study, forestomach rumen samples were collected on two occasions on the North Slope. When incubated with anthracene and naphthalene (PAH), these pollutants were degraded in the majority of sample sets. All simple aromatic hydrocarbons (benzine, toluene, xylenes, ethylbenzene) were degraded. PCBs were biodegraded by microbes from only two of the whales. Variable results were found with picric acid, trinitrotoluene (TNT), andmore » atrazine, and were likely due to analytical difficulties. Whale forestomach bacteria have adapted to an ecological niche where flow rates, mixing, and catabolism occur at rapid rates. These rates and the ability to metabolize complex molecules far exceed those of aerobic sediment and soil bacteria in biodegradation of environmental pollutants.« less

High-performance green flexible electronics based on biodegradable cellulose nanofibril paper

PubMed Central

Jung, Yei Hwan; Chang, Tzu-Hsuan; Zhang, Huilong; Yao, Chunhua; Zheng, Qifeng; Yang, Vina W.; Mi, Hongyi; Kim, Munho; Cho, Sang June; Park, Dong-Wook; Jiang, Hao; Lee, Juhwan; Qiu, Yijie; Zhou, Weidong; Cai, Zhiyong; Gong, Shaoqin; Ma, Zhenqiang

2015-01-01

Today's consumer electronics, such as cell phones, tablets and other portable electronic devices, are typically made of non-renewable, non-biodegradable, and sometimes potentially toxic (for example, gallium arsenide) materials. These consumer electronics are frequently upgraded or discarded, leading to serious environmental contamination. Thus, electronic systems consisting of renewable and biodegradable materials and minimal amount of potentially toxic materials are desirable. Here we report high-performance flexible microwave and digital electronics that consume the smallest amount of potentially toxic materials on biobased, biodegradable and flexible cellulose nanofibril papers. Furthermore, we demonstrate gallium arsenide microwave devices, the consumer wireless workhorse, in a transferrable thin-film form. Successful fabrication of key electrical components on the flexible cellulose nanofibril paper with comparable performance to their rigid counterparts and clear demonstration of fungal biodegradation of the cellulose-nanofibril-based electronics suggest that it is feasible to fabricate high-performance flexible electronics using ecofriendly materials. PMID:26006731

Organic pollutant loading and biodegradability of firefighting foam

NASA Astrophysics Data System (ADS)

Zhang, Xian-Zhong; Bao, Zhi-ming; Hu, Cheng; Li-Shuai, Jing; Chen, Yang

2017-11-01

Firefighting foam has been widely used as the high-performance extinguishing agent in extinguishing the liquid poor fire. It was concerned for its environmental impacts due to its massive usage. In this study, the organic loading level and the biodegradability of 18 firefighting foams commonly used in China were evaluated and compared. The COD and TOC of firefighting foam concentrates are extremely high. Furthermore, those of foam solutions are also much higher than regular wastewater. The COD/TOC ratio of synthetic foams are higher than protein foams. The 28-day biodegradation rates of 18 firefighting foams are all over 60%, indicating that they are all ready biodegradable. Protein foams (P, FP and FFFP) have the higher organic loading and lower 28-day biodegradation rates compared to the synthetic foams (Class A foam, AFFF and S). The short and long-term impact of protein foams on the environment are larger than synthetic foams.

High-performance green flexible electronics based on biodegradable cellulose nanofibril paper.

PubMed

Jung, Yei Hwan; Chang, Tzu-Hsuan; Zhang, Huilong; Yao, Chunhua; Zheng, Qifeng; Yang, Vina W; Mi, Hongyi; Kim, Munho; Cho, Sang June; Park, Dong-Wook; Jiang, Hao; Lee, Juhwan; Qiu, Yijie; Zhou, Weidong; Cai, Zhiyong; Gong, Shaoqin; Ma, Zhenqiang

2015-05-26

Today's consumer electronics, such as cell phones, tablets and other portable electronic devices, are typically made of non-renewable, non-biodegradable, and sometimes potentially toxic (for example, gallium arsenide) materials. These consumer electronics are frequently upgraded or discarded, leading to serious environmental contamination. Thus, electronic systems consisting of renewable and biodegradable materials and minimal amount of potentially toxic materials are desirable. Here we report high-performance flexible microwave and digital electronics that consume the smallest amount of potentially toxic materials on biobased, biodegradable and flexible cellulose nanofibril papers. Furthermore, we demonstrate gallium arsenide microwave devices, the consumer wireless workhorse, in a transferrable thin-film form. Successful fabrication of key electrical components on the flexible cellulose nanofibril paper with comparable performance to their rigid counterparts and clear demonstration of fungal biodegradation of the cellulose-nanofibril-based electronics suggest that it is feasible to fabricate high-performance flexible electronics using ecofriendly materials.

High-performance green flexible electronics based on biodegradable cellulose nanofibril paper

NASA Astrophysics Data System (ADS)

Jung, Yei Hwan; Chang, Tzu-Hsuan; Zhang, Huilong; Yao, Chunhua; Zheng, Qifeng; Yang, Vina W.; Mi, Hongyi; Kim, Munho; Cho, Sang June; Park, Dong-Wook; Jiang, Hao; Lee, Juhwan; Qiu, Yijie; Zhou, Weidong; Cai, Zhiyong; Gong, Shaoqin; Ma, Zhenqiang

2015-05-01

Today's consumer electronics, such as cell phones, tablets and other portable electronic devices, are typically made of non-renewable, non-biodegradable, and sometimes potentially toxic (for example, gallium arsenide) materials. These consumer electronics are frequently upgraded or discarded, leading to serious environmental contamination. Thus, electronic systems consisting of renewable and biodegradable materials and minimal amount of potentially toxic materials are desirable. Here we report high-performance flexible microwave and digital electronics that consume the smallest amount of potentially toxic materials on biobased, biodegradable and flexible cellulose nanofibril papers. Furthermore, we demonstrate gallium arsenide microwave devices, the consumer wireless workhorse, in a transferrable thin-film form. Successful fabrication of key electrical components on the flexible cellulose nanofibril paper with comparable performance to their rigid counterparts and clear demonstration of fungal biodegradation of the cellulose-nanofibril-based electronics suggest that it is feasible to fabricate high-performance flexible electronics using ecofriendly materials.

Monitoring of the aerobe biodegradation of chlorinated organic solvents by stable isotope analysis

NASA Astrophysics Data System (ADS)

Horváth, Anikó; Futó, István; Palcsu, László

2014-05-01

Our chemical-biological basic research aims to eliminate chlorinated environmental contaminants from aquifers around industrial areas in the frame of research program supported by the European Social Fund (TÁMOP-4.2.2.A-11/1/KONV-2012-0043). The most careful and simplest way includes the in situ biodegradation with the help of cultured and compound specific strains. Numerous members of Pseudomonas bacteria are famous about function of bioremediation. They can metabolism the environmental hazardous chemicals like gas oils, dyes, and organic solvents. Our research based on the Pseudomonas putida F1 strain, because its ability to degrade halogenated hydrocarbons such as trichloroethylene. Several methods were investigated to estimate the rate of biodegradation, such as the measurement of the concentration of the pollutant along the contamination pathway, the microcosm's studies or the compound specific stable isotope analysis. In this area in the Transcarpathian basin we are pioneers in the stable isotope monitoring of biodegradation. The main goal is to find stable isotope fractionation factors by stable isotope analysis, which can help us to estimate the rate and effectiveness of the biodegradation. The subsequent research period includes the investigation of the method, testing its feasibility and adaptation in the environment. Last but not least, the research gives an opportunity to identify the producer of the contaminant based on the stable isotope composition of the contaminant.

New insights into polyurethane biodegradation and realistic prospects for the development of a sustainable waste recycling process.

PubMed

Cregut, Mickael; Bedas, M; Durand, M-J; Thouand, G

2013-12-01

Polyurethanes are polymeric plastics that were first used as substitutes for traditional polymers suspected to release volatile organic hazardous substances. The limitless conformations and formulations of polyurethanes enabled their use in a wide variety of applications. Because approximately 10 Mt of polyurethanes is produced each year, environmental concern over their considerable contribution to landfill waste accumulation appeared in the 1990s. To date, no recycling processes allow for the efficient reuse of polyurethane waste due to their high resistance to (a)biotic disturbances. To find alternatives to systematic accumulation or incineration of polyurethanes, a bibliographic analysis was performed on major scientific advances in the polyurethane (bio)degradation field to identify opportunities for the development of new technologies to recondition this material. Until polymers exhibiting oxo- or hydro-biodegradative traits are generated, conventional polyurethanes that are known to be only slightly biodegradable are of great concern. The research focused on polyurethane biodegradation highlights recent attempts to reprocess conventional industrial polyurethanes via microbial or enzymatic degradation. This review describes several wonderful opportunities for the establishment of new processes for polyurethane recycling. Meeting these new challenges could lead to the development of sustainable management processes involving polymer recycling or reuse as environmentally safe options for industries. The ability to upgrade polyurethane wastes to chemical compounds with a higher added value would be especially attractive. © 2013.

Atomic elucidation of the cyclodextrin effects on DDT solubility and biodegradation.

PubMed

Ren, Baiping; Zhang, Mingzhen; Gao, Huipeng; Zheng, Jie; Jia, Lingyun

2016-07-14

DDT (1,1,1-trichloro-2.2-bis(p-chlorophenyl)ethane), one of the most abused insecticides, is a highly hazardous component for both human health and environmental applications. The biodegradation of DDT into non-toxic, environmentally benign components is strongly limited by the poor bioavailability of DDT. In this work, we combined experiments and molecular simulations to examine the effect of three cyclodextrins (α-, β-, and γ-CD) on their structure-specific interactions with DDT, specifically in relation to DDT solubility and biodegradability. It was found that all three CDs were able to bind to DDT with their inner hydrophobic cavity and different binding affinities and orientations, demonstrating their ability to improve DDT solubility. Different from the strong binding between DDT and β-/γ-CDs via a fully DDT bury mode, α-CD had a relatively weak binding with DDT via a partial DDT bury mode, which allowed DDT to be readily disassociated from α-CD at the lipid membrane interface, followed by DDT permeation into and across the cell membrane. The different binding modes between DDT and CDs explain why only α-CD can promote the bioavailability and biodegradation of DDT by simultaneously increasing its aqueous solubility and membrane interaction. This work provides structural-based binding information for the further modification and optimization of these three CDs to enhance their solubility and biodegradability of DDT.

The environmental impact of 4(5)-methylbenzotriazole from aircraft deicing operations

NASA Astrophysics Data System (ADS)

Cornell, Jeffrey Scott

2002-01-01

Hundreds of millions of gallons of aircraft deicer fluid (ADF) are applied to aircraft and runway surfaces annually. Recently public and regulatory attention has forced the air transport industry and military aviation community to examine the environmental impacts of aircraft deicing operations (ADOs), and to seek a balance between flight safety and environmental impact. Little data exists which is useful to evaluate the impact of ADF additives. 4(5)-methylbenzotriazole (MeBT) is used in a variety of industrial and commercial fluids to inhibit metal corrosion; it is a standard additive to most common ADF (approx. 0.5%). This MeBT component is actually a mixture of two isomers: 4-methylbenzotriazole (4-MeBT) and 5-methylbenzotriazole (5-MeBT). A significant amount of MeBT enters the natural environment through aircraft deicing operations. Research was conducted to address important data gaps impacting the ability to assess the environmental impact of MeBT and ADOs. Matrixed toxicity studies were conducted to determine the effect of different additives on ADF ecotoxicity. Aerobic liquid batch-fed microcosms were employed to investigate how MeBT affects the toxicity of wastewater containing ADF, describe how MeBT affects the aerobic biodegradation of propylene glycol (PG), and determine the biodegradability of MeBT. Field samples from contaminated areas were collected and analyzed for comparison. Cell energy production and electron transport assays were conducted to determine if MeBT was capable of disrupting oxidative phosphorylation via uncoupling, as its chemical structure would suggest. MicrotoxRTM studies indicated MeBT was toxic to test bacteria below 10 mg/L. C. dubia and P. promelas , however, were less sensitive to MeBT than bacteria but more sensitive to other ADF additives. The effect of MeBT on PG biodegradation was complex and concentration-dependent. Cell yield and PG biodegradation rates generally decreased with increasing reactor MeBT concentration. ATP:INT assay data in bioreactors containing 10 mg McBT/L suggested ATP production uncoupled from electron transport. Oxygen consumption and aerobic PG biodegradation was completely inhibited between above 2,000 mg MeBT/L. MeBT was not degraded when PG was present above 0.5 mg/L in well-mixed aerobic conditions. 5-MeBT was biodegradable under a variety of aerobic laboratory conditions (when PG was not present) while 4-MeBT was recalcitrant.

EMERGING TECHNOLOGY BULLETIN: TWO-ZONE PCE BIOREMEDIATION SYSTEM - ABB ENVIRONMENTAL SERVICES, INC. - U.S. ENVIRONMENTAL PROTECTION AGENCY

EPA Science Inventory

ABB Environmental Services, Inc.'s (ABB-ES), research has demonstrated that sequential anaerobic/aerobic biodegradation of tetrachloroethylene (PCE) is feasible if the proper conditions can be established. The anaerobic process can potentially completely dechlorinate PCE. Howeve...

Identification of new metabolic pathways in the enantioselective fungicide tebuconazole biodegradation by Bacillus sp. 3B6.

PubMed

Youness, Mohamed; Sancelme, Martine; Combourieu, Bruno; Besse-Hoggan, Pascale

2018-06-05

The use of triazole fungicides in various fields ranging from agriculture to therapy, can cause long-term undesirable effects on different organisms from various environmental compartments and lead to resistance phenomena (even in humans) due to their extensive use and persistence. Their occurrence in various water bodies has increased and tebuconazole, in particular, is often detected, sometimes in high concentration. Only a few bacterial and fungal strains have been isolated and found to biotransform this fungicide, described as not easily biodegradable. Nevertheless, the knowledge of efficient degrading-strains and metabolites potentially formed could improve bioremediation process and global overview of risk assessment. Therefore, a broad screening of microorganisms, isolated from various environmental compartments or from commercially-available strain collections, allowed us to find six bacterial strains able to biotransform tebuconazole. The most efficient one was studied further: this environmental strain Bacillus sp. 3B6 biotransforms the fungicide enantioselectively (ee = 18%) into two hydroxylated metabolites, one of them being transformed in its turn to alkene by a biotic dehydration reaction. This original enantioselective pathway shows that racemic pesticides should be treated by the environmental risk assessment authorities as a mixture of two compounds because persistence, biodegradation, bioaccumulation and toxicity often show chiral dependence. Copyright © 2018 Elsevier B.V. All rights reserved.

Physicochemical properties and biodegradability of organically functionalized colloidal silica particles in aqueous environment.

PubMed

Schneider, Mandy; Meder, Fabian; Haiß, Annette; Treccani, Laura; Rezwan, Kurosch; Kümmerer, Klaus

2014-03-01

Engineered sub-micron particles are being used in many technical applications, leading to an increasing introduction into the aquatic environment. Only a few studies have dealt with the biodegradability of non-functionalized organic particles. In fact the knowledge of organically surface functionalized colloids is nearly non-existent. We have investigated the biodegradability of organically surface functionalized silica (SiO2) particles bearing technically relevant groups such as amino-, carboxyl-, benzyl-, sulfonate-, chloro-, and phosphatoethyl-derivatized alkyls. Essential physicochemical properties including zeta potential, isoelectric point, morphology, surface area, porosity, surface density, and elemental composition of the particles were investigated, followed by biodegradability testing using the Closed Bottle Test (OECD 301D). None of the particles met the biodegradability threshold value of 60%. Only a slight biodegradation was revealed for SiO2-Benzyl (13.7±6.7%) and for SiO2-3-Chlorpropane (10.8±1.5%). For the other particles biodegradability was below the normal background fluctuation of 5%. The results were different of those obtained from structurally similar chemicals not being functionalized on the particle surface and from general rules of structure-biodegradation prediction of organic molecules. Therefore, our results suggest that the attachment of the organic groups heavily reduces their biodegradability, increases their residence time and possibility for adverse effects to environmental species. Copyright © 2013 Elsevier Ltd. All rights reserved.

Degradation of Oxo-Biodegradable Plastic by Pleurotus ostreatus

PubMed Central

da Luz, José Maria Rodrigues; Paes, Sirlaine Albino; Nunes, Mateus Dias; da Silva, Marliane de Cássia Soares; Kasuya, Maria Catarina Megumi

2013-01-01

Growing concerns regarding the impact of the accumulation of plastic waste over several decades on the environmental have led to the development of biodegradable plastic. These plastics can be degraded by microorganisms and absorbed by the environment and are therefore gaining public support as a possible alternative to petroleum-derived plastics. Among the developed biodegradable plastics, oxo-biodegradable polymers have been used to produce plastic bags. Exposure of this waste plastic to ultraviolet light (UV) or heat can lead to breakage of the polymer chains in the plastic, and the resulting compounds are easily degraded by microorganisms. However, few studies have characterized the microbial degradation of oxo-biodegradable plastics. In this study, we tested the capability of Pleurotus ostreatus to degrade oxo-biodegradable (D2W) plastic without prior physical treatment, such as exposure to UV or thermal heating. After 45 d of incubation in substrate-containing plastic bags, the oxo-biodegradable plastic, which is commonly used in supermarkets, developed cracks and small holes in the plastic surface as a result of the formation of hydroxyl groups and carbon-oxygen bonds. These alterations may be due to laccase activity. Furthermore, we observed the degradation of the dye found in these bags as well as mushroom formation. Thus, P. ostreatus degrades oxo-biodegradable plastics and produces mushrooms using this plastic as substrate. PMID:23967057

Degradation of oxo-biodegradable plastic by Pleurotus ostreatus.

PubMed

da Luz, José Maria Rodrigues; Paes, Sirlaine Albino; Nunes, Mateus Dias; da Silva, Marliane de Cássia Soares; Kasuya, Maria Catarina Megumi

2013-01-01

Growing concerns regarding the impact of the accumulation of plastic waste over several decades on the environmental have led to the development of biodegradable plastic. These plastics can be degraded by microorganisms and absorbed by the environment and are therefore gaining public support as a possible alternative to petroleum-derived plastics. Among the developed biodegradable plastics, oxo-biodegradable polymers have been used to produce plastic bags. Exposure of this waste plastic to ultraviolet light (UV) or heat can lead to breakage of the polymer chains in the plastic, and the resulting compounds are easily degraded by microorganisms. However, few studies have characterized the microbial degradation of oxo-biodegradable plastics. In this study, we tested the capability of Pleurotus ostreatus to degrade oxo-biodegradable (D2W) plastic without prior physical treatment, such as exposure to UV or thermal heating. After 45 d of incubation in substrate-containing plastic bags, the oxo-biodegradable plastic, which is commonly used in supermarkets, developed cracks and small holes in the plastic surface as a result of the formation of hydroxyl groups and carbon-oxygen bonds. These alterations may be due to laccase activity. Furthermore, we observed the degradation of the dye found in these bags as well as mushroom formation. Thus, P. ostreatus degrades oxo-biodegradable plastics and produces mushrooms using this plastic as substrate.

Effects of carbon nanotubes on atrazine biodegradation by Arthrobacter sp.

PubMed

Zhang, Chengdong; Li, Mingzhu; Xu, Xu; Liu, Na

2015-04-28

The environmental risks of engineered nanoparticles have attracted attention. However, little is known regarding the effects of carbon nanotubes (CNTs) on the biodegradation and persistence of organic contaminants in water. We investigated the impacts of pristine and oxidized multiwalled CNTs on the atrazine biodegradation rate and efficiency using Arthrobacter sp. At a concentration of 25mg/L, the CNTs enhanced the biodegradation rate by up to 20%; however, at a concentration of 100mg/L, the CNTs decreased the biodegradation rate by up to 50%. The stimulation effects resulted from enhanced bacterial growth and the overexpression of degradation genes. The inhibitory effects resulted from the toxicity of the CNTs at high concentrations. The differences between the two CNTs at tested concentrations were not significant. The biodegradation efficiency was not impacted by adsorption, and the pre-adsorbed atrazine on the CNTs was fully biodegraded when the CNT concentration was ≤25mg/L. This finding was consistent with the lack of observable desorption hysteresis for atrazine on the tested CNTs. Our results indicate that CNTs can enhance or inhibit biodegradation through a balance of two effects: the toxic effects on microbial activity and the effects of the changing bioavailability that result from adsorption and desorption. Copyright © 2015 Elsevier B.V. All rights reserved.

Biodegradation of polystyrene-graft-starch copolymers in three different types of soil.

PubMed

Nikolic, Vladimir; Velickovic, Sava; Popovic, Aleksandar

2014-01-01

Materials based on polystyrene and starch copolymers are used in food packaging, water pollution treatment, and textile industry, and their biodegradability is a desired characteristic. In order to examine the degradation patterns of modified, biodegradable derivates of polystyrene, which may keep its excellent technical features but be more environmentally friendly at the same time, polystyrene-graft-starch biomaterials obtained by emulsion polymerization in the presence of new type of initiator/activator pair (potassium persulfate/different amines) were subjected to 6-month biodegradation by burial method in three different types of commercially available soils: soil rich in humus and soil for cactus and orchid growing. Biodegradation was monitored by mass decrease, and the highest degradation rate was achieved in soil for cactus growing (81.30%). Statistical analysis proved that microorganisms in different soil samples have different ability of biodegradation, and there is a significant negative correlation between the share of polystyrene in copolymer and degree of biodegradation. Grafting of polystyrene on starch on one hand prevents complete degradation of starch that is present (with maximal percentage of degraded starch ranging from 55 to 93%), while on the other hand there is an upper limit of share of polystyrene in the copolymer (ranging from 37 to 77%) that is preventing biodegradation of degradable part of copolymers.

The Effects of Molecular Properties on Ready Biodegradation of Aromatic Compounds in the OECD 301B CO2 Evolution Test.

PubMed

He, Mei; Mei, Cheng-Fang; Sun, Guo-Ping; Li, Hai-Bei; Liu, Lei; Xu, Mei-Ying

2016-07-01

Ready biodegradation is the primary biodegradability of a compound, which is used for discriminating whether a compound could be rapidly and readily biodegraded in the natural ecosystems in a short period and has been applied extensively in the environmental risk assessment of many chemicals. In this study, the effects of 24 molecular properties (including 2 physicochemical parameters, 10 geometrical parameters, 6 topological parameters, and 6 electronic parameters) on the ready biodegradation of 24 kinds of synthetic aromatic compounds were investigated using the OECD 301B CO2 Evolution test. The relationship between molecular properties and ready biodegradation of these aromatic compounds varied with molecular properties. A significant inverse correlation was found for the topological parameter TD, five geometrical parameters (Rad, CAA, CMA, CSEV, and N c), and the physicochemical parameter K ow, and a positive correlation for two topological parameters TC and TVC, whereas no significant correlation was observed for any of the electronic parameters. Based on the correlations between molecular properties and ready biodegradation of these aromatic compounds, the importance of molecular properties was demonstrated as follows: geometrical properties > topological properties > physicochemical properties > electronic properties. Our study first demonstrated the effects of molecular properties on ready biodegradation by a number of experiment data under the same experimental conditions, which should be taken into account to better guide the ready biodegradation tests and understand the mechanisms of the ready biodegradation of aromatic compounds.

Biodegradation of the cyclic nitramine explosives RDX, HMX, and CL-20.

PubMed

Crocker, Fiona H; Indest, Karl J; Fredrickson, Herbert L

2006-11-01

Cyclic nitramine explosives are synthesized globally mainly as military munitions, and their use has resulted in environmental contamination. Several biodegradation pathways have been proposed, and these are based mainly on end-product characterization because many of the metabolic intermediates are hypothetical and unstable in water. Biodegradation mechanisms for cyclic nitramines include (a) formation of a nitramine free radical and loss of nitro functional groups, (b) reduction of nitro functional groups, (c) direct enzymatic cleavage, (d) alpha-hydroxylation, or (e) hydride ion transfer. Pathway intermediates spontaneously decompose in water producing nitrite, nitrous oxide, formaldehyde, or formic acid as common end-products. In vitro enzyme and functional gene expression studies have implicated a limited number of enzymes/genes involved in cyclic nitramine catabolism. Advances in molecular biology methods such as high-throughput DNA sequencing, microarray analysis, and nucleic acid sample preparation are providing access to biochemical and genetic information on cultivable and uncultivable microorganisms. This information can provide the knowledge base for rational engineering of bioremediation strategies, biosensor development, environmental monitoring, and green biosynthesis of explosives. This paper reviews recent developments on the biodegradation of cyclic nitramines and the potential of genomics to identify novel functional genes of explosive metabolism.

Perils of categorical thinking: "Oxic/anoxic" conceptual model in environmental remediation

USGS Publications Warehouse

Bradley, Paul M.

2012-01-01

Given ambient atmospheric oxygen concentrations of about 21 percent (by volume), the lower limit for reliable quantitation of dissolved oxygen concentrations in groundwater samples is in the range of 0.1–0.5 mg/L. Frameworks for assessing in situ redox condition are often applied using a simple two-category (oxic/anoxic) model of oxygen condition. The "oxic" category defines the environmental range in which dissolved oxygen concentrations are clearly expected to impact contaminant biodegradation, either by supporting aerobic biodegradation of electron-donor contaminants like petroleum hydrocarbons or by inhibiting anaerobic biodegradation of electron-acceptor contaminants like chloroethenes. The tendency to label the second category "anoxic" leads to an invalid assumption that oxygen is insignificant when, in fact, the dissolved oxygen concentration is less than detection but otherwise unknown. Expressing dissolved oxygen concentrations as numbers of molecules per volume, dissolved oxygen concentrations that fall below the 0.1 mg/L field detection limit range from 1 to 1017 molecules/L. In light of recent demonstrations of substantial oxygen-linked biodegradation of chloroethene contaminants at dissolved oxygen concentrations well below the 0.1–0.5 mg/L field detection limit, characterizing "less than detection" oxygen concentrations as "insignificant" is invalid.

Slow-Releasing Oxygen Source

EPA Science Inventory

Subsurface pollution is an environmental issue of great concern in the United States and around the world. Bioremediation has proven to be an effective and environmentally preferable treatment for biodegradable pollutants, such as methyl tertiary butyl ether, toluene, ethylbenze...

Biodegradable containers from green waste materials

NASA Astrophysics Data System (ADS)

Sartore, Luciana; Schettini, Evelia; Pandini, Stefano; Bignotti, Fabio; Vox, Giuliano; D'Amore, Alberto

2016-05-01

Novel biodegradable polymeric materials based on protein hydrolysate (PH), derived from waste products of the leather industry, and poly(ethylene glycol) diglycidyl ether (PEG) or epoxidized soybean oil (ESO) were obtained and their physico-chemical properties and mechanical behaviour were evaluated. Different processing conditions and the introduction of fillers of natural origin, as saw dust and wood flour, were used to tailor the mechanical properties and the environmental durability of the product. The biodegradable products, which are almost completely manufactured from renewable-based raw materials, look promising for several applications, particularly in agriculture for the additional fertilizing action of PH or in packaging.

Combining SBR systems for chemical and biological treatment: the destruction of the nerve agent VX.

PubMed

Irvine, R L; Haraburda, S S; Galbis-Reig, C

2004-01-01

The US Army is pilot testing the neutralization of VX nerve agent stockpiled at Newport, Indiana using caustic hydrolysis in a Sequencing Batch Reactor (SBR). The resulting hydrolysate was tested at the bench-scale for treatment with activated sludge biodegradation in two distinct studies, one in the SBR and another, in the PACT process. The feed to both biological systems was pretreated to enhance the biodegradability of the hydrolysis products. Both biodegradation studies demonstrated that the hydrolysate could easily meet the Chemical Weapons Convention treaty and US environmental regulations following pretreatment.

Re-Designing of Existing Pharmaceuticals for Environmental Biodegradability: A Tiered Approach with β-Blocker Propranolol as an Example.

PubMed

Rastogi, Tushar; Leder, Christoph; Kümmerer, Klaus

2015-10-06

Worldwide, contamination of aquatic systems with micropollutants, including pharmaceuticals, is one of the challenges for sustainable management of water resources. Although micropollutants are present at low concentrations, many of them raise considerable toxicological concerns, particularly when present as components of complex mixtures. Recent research has shown that this problem cannot be sustainably solved with advanced effluent treatment. Therefore, an alternative that might overcome these environmental problems is the design of new pharmaceutical molecules or the redesign of existing pharmaceutical molecules that present the functionality needed for their application and have improved environmental biodegradability. Such redesigning can be performed by small molecular changes in the drug molecule with intact drug moiety which could incorporate the additional attribute such as biodegradability while retaining its pharmacological potency. This proof of concept study provides an approach for the rational redesign of a given pharmaceutical (Propranolol as an example). New derivatives with small molecular changes as compared to propranolol molecule were generated by a nontargeted photolysis process. Generated derivatives with intact drug moieties (an aromatic ring and a β-ethanolamine moiety) were further screened for aerobic biodegradability and pharmacological potency. The feasibility of the approach of redesigning an existing pharmaceutical through nontargeted generation of new derivatives with intact drug moiety and through subsequent screening was demonstrated in this study. Application of such approaches in turn might contribute to the protection of water resources in a truly sustainable manner.

Evaluation of the hazardous impact of landfill leachates by toxicity and biodegradability tests.

PubMed

Kalcíková, G; Vávrová, M; Zagorc-Koncan, J; Gotvajn, A Zgajnar

2011-01-01

The aim of our research was to assess the ecotoxicity and biodegradability of leachates originating from two parts of a municipal landfill before and after biological treatment in the existing treatment plant. Biotests represent important tools for adequate environmental characterization of landfill leachates and could be helpful in reliable assessment and monitoring of the treatment plant efficiency. For ecotoxicity testing of landfill leachate before and after biological treatment, different organisms were chosen: the bacteria Vibrio fischeri, a mixed culture of activated sludge, duckweed Lemna minor, white mustard Sinapis alba, brine shrimp Artemia salina, and water flea Daphnia magna. For assessment of biodegradability, the method for determination of oxygen demand in a closed respirometer was used. The investigated leachates were heavily polluted, and in some cases, effluent limits were exceeded even after treatment. Results indicated that toxicity tests and physico-chemical parameters determined before and after treatment equivalently assess the efficiency of the existing treatment plant. However, the investigated leachates showed higher toxicity to Daphnia magna and especially to Lemna minor in contrast to Vibrio fischeri and Artemia salina (neither was sensitive to any of the leachates). No leachates were readily biodegradable. Experiments confirmed that the battery of toxicity tests should be applied for more comprehensive assessment of landfill leachate treatment and for reliable assessment of the treated leachate's subsequent environmental impact. It was confirmed that treated leachate, in spite of its better physico-chemical characteristics, still represents a potential environmental risk and thus should not be released into the environment.

Mechanistic investigation of industrial wastewater naphthenic acids removal using granular activated carbon (GAC) biofilm based processes.

PubMed

Islam, Md Shahinoor; Zhang, Yanyan; McPhedran, Kerry N; Liu, Yang; Gamal El-Din, Mohamed

2016-01-15

Naphthenic acids (NAs) found in oil sands process-affected waters (OSPW) have known environmental toxicity and are resistant to conventional wastewater treatments. The granular activated carbon (GAC) biofilm treatment process has been shown to effectively treat OSPW NAs via combined adsorption/biodegradation processes despite the lack of research investigating their individual contributions. Presently, the NAs removals due to the individual processes of adsorption and biodegradation in OSPW bioreactors were determined using sodium azide to inhibit biodegradation. For raw OSPW, after 28 days biodegradation and adsorption contributed 14% and 63% of NA removal, respectively. For ozonated OSPW, biodegradation removed 18% of NAs while adsorption reduced NAs by 73%. Microbial community 454-pyrosequencing of bioreactor matrices indicated the importance of biodegradation given the diverse carbon degrading families including Acidobacteriaceae, Ectothiorhodospiraceae, and Comamonadaceae. Overall, results highlight the ability to determine specific processes of NAs removals in the combined treatment process in the presence of diverse bacteria metabolic groups found in GAC bioreactors. Copyright © 2015 Elsevier B.V. All rights reserved.

Environmentally friendly and biobased lubricants

USDA-ARS?s Scientific Manuscript database

Biobased and environmentally friendly lubricants are finding applications in many areas ranging from hydraulic fluids to grease. They offer excellent biodegradability and very low ecotoxicity; high viscosity index; improved tribological properties; lower volatility and flash points relative to petro...

CHIRAL CHLORDANE SIGNATURES IN USGS NATIONAL WATER-QUALITY ASSESSMENT PROGRAM SEDIMENT SAMPLES

EPA Science Inventory

More than 260 important environmental contaminants are chiral (having structures that are nonsuperimposible mirror images). Although enantiomer pairs have identical physical-chemical properties, their toxicity, biodegradation, and environmental fate often are different. Cyclodex...

Synthesis and Characterization of Environmentally Benign Nanoparticles

EPA Science Inventory

There has been a growing interest in replacing current non-biodegradable and toxic nanosystems with environmentally benign biopolymer based ones to minimize post-utilization hazards due to uncontrolled accumulation of nanoparticles in the environment. Lignin based nanoparticles (...

Improvement of Life Expectancy of Jute Based Needlepunched Geotextiles Through Bitumen Treatment

NASA Astrophysics Data System (ADS)

Ghosh, S. K.; Ray Gupta, K.; Bhattacharyya, R.; Sahu, R. B.; Mandol, S.

2014-12-01

Geotextiles have witnessed unrivalled growth worldwide in recent years in the field of different civil engineering constructions. The world of Geotextiles includes mainly non-biodegradable synthetic materials which are not environmentally compatible. With the increasing human awareness on environmental pollution aspects, biodegradable Jute Geotextile is increasingly gaining ground over its synthetic non-biodegradable counterpart. Though Jute is advantageous for its complete biodegradability in one hand but on the other hand it is disadvantageous for its poor microbial resistance and quicker biodegradation particularly under moist soil conditions, when applied as Geotextiles under soil. Therefore, it is a great challenge to the present researchers to make jute more microbial resistant (rot resistant) keeping its biodegradability intact during its performance period. Thorough investigation and study regarding the improvement of the durability of natural Jute Geotextile reveals the fact that though several attempts including chemical treatments have been made to enhance the life expectancy of jute fabrics yet these methods were neither found to be suitable nor techno-economically viable. Therefore, in order to accomplish the objective and based on the researchers' report of satisfactory thermal compatibility between hot bitumen and jute nonwoven fabrics, in the present study Bitumen emulsion with essential additives has been applied following a special technique, apart from the conventional method, on the Grey Jute Nonwoven Fabrics in different add on percentages to make a comparative assessment of the performance of both Grey Jute Fabrics and Bituminized Jute Nonwoven Fabrics by Soil Burial Test as per the BIS standard test method. The test results revealed that the durability and performance of the Bituminized Nonwoven Jute Fabrics are much better than that of Grey Jute Nonwoven Fabrics.

High-performance green semiconductor devices: materials, designs, and fabrication

NASA Astrophysics Data System (ADS)

Jung, Yei Hwan; Zhang, Huilong; Gong, Shaoqin; Ma, Zhenqiang

2017-06-01

From large industrial computers to non-portable home appliances and finally to light-weight portable gadgets, the rapid evolution of electronics has facilitated our daily pursuits and increased our life comforts. However, these rapid advances have led to a significant decrease in the lifetime of consumer electronics. The serious environmental threat that comes from electronic waste not only involves materials like plastics and heavy metals, but also includes toxic materials like mercury, cadmium, arsenic, and lead, which can leak into the ground and contaminate the water we drink, the food we eat, and the animals that live around us. Furthermore, most electronics are comprised of non-renewable, non-biodegradable, and potentially toxic materials. Difficulties in recycling the increasing amount of electronic waste could eventually lead to permanent environmental pollution. As such, discarded electronics that can naturally degrade over time would reduce recycling challenges and minimize their threat to the environment. This review provides a snapshot of the current developments and challenges of green electronics at the semiconductor device level. It looks at the developments that have been made in an effort to help reduce the accumulation of electronic waste by utilizing unconventional, biodegradable materials as components. While many semiconductors are classified as non-biodegradable, a few biodegradable semiconducting materials exist and are used as electrical components. This review begins with a discussion of biodegradable materials for electronics, followed by designs and processes for the manufacturing of green electronics using different techniques and designs. In the later sections of the review, various examples of biodegradable electrical components, such as sensors, circuits, and batteries, that together can form a functional electronic device, are discussed and new applications using green electronics are reviewed.

Use of Respirometry To Determine the Effect of Nutrient Enhancement on JP-8 Biodegradability.

DTIC Science & Technology

1995-11-27

present, environmental conditions, and certainly indigenous microbial communities present ( Atlas and Bartha , 1993). In general, biodegradation can be...Richard Bartha . Microbial Ecology : Fundementals and Applications. Redwood City, CA: The Benjamin Cummings Publishing Company, Inc, 1993. Autry...products caused by microorganisms or their enzymes ( Atlas and Bartha , 1993). It is greatly influenced by the nature and amount of the target compound

Minuteman III Motor-Generator Bearing Grease Replacement

DTIC Science & Technology

2013-07-01

Biodegradation is a natural process caused by the action of microorganisms in the presence of oxygen, nitrogen, phosphorous, and trace minerals. Organic... biodegradable are considered less toxic and more environmentally friendly. Currently, this technology has been mandated in order to reduce the ...AFB2 grease and Capella WF-68 oil currently used in the MINUTEMAN III Motor-generator (M-G) Bearing Systems. Due to the unavailability

Annual Report to Congress, Fiscal Year 1997. A Report by The Council of the Strategic Environmental Research and Development Program

DTIC Science & Technology

1998-03-01

Discovery of Novel Enzymatic Reactions and Determination of Biodegradation Mechanisms and Pathways. b. Phytoremediation of Explosives Contaminated...Groundwater using Wetlands and Aquatic Plants. c. Phytoremediation of Munitions Contaminated Soils. d. Enhanced TNT Biodegradation Through Genetic Manipulation...Microbial Communities Active in the Enhanced Aerobic Treatment of Chlorinated Ethenes. c. Phytoremediation of Shallow Chlorinated Solvent Plumes

Environmental drivers of differences in microbial community structure in crude oil reservoirs across a methanogenic gradient

USGS Publications Warehouse

Shelton, Jenna L.; Akob, Denise M.; McIntosh, Jennifer C.; Fierer, Noah; Spear, John R.; Warwick, Peter D.; McCray, John E.

2016-01-01

Stimulating in situ microbial communities in oil reservoirs to produce natural gas is a potentially viable strategy for recovering additional fossil fuel resources following traditional recovery operations. Little is known about what geochemical parameters drive microbial population dynamics in biodegraded, methanogenic oil reservoirs. We investigated if microbial community structure was significantly impacted by the extent of crude oil biodegradation, extent of biogenic methane production, and formation water chemistry. Twenty-two oil production wells from north central Louisiana, USA, were sampled for analysis of microbial community structure and fluid geochemistry. Archaea were the dominant microbial community in the majority of the wells sampled. Methanogens, including hydrogenotrophic and methylotrophic organisms, were numerically dominant in every well, accounting for, on average, over 98% of the total Archaea present. The dominant Bacteria groups were Pseudomonas, Acinetobacter, Enterobacteriaceae, and Clostridiales, which have also been identified in other microbially-altered oil reservoirs. Comparing microbial community structure to fluid (gas, water, and oil) geochemistry revealed that the relative extent of biodegradation, salinity, and spatial location were the major drivers of microbial diversity. Archaeal relative abundance was independent of the extent of methanogenesis, but closely correlated to the extent of crude oil biodegradation; therefore, microbial community structure is likely not a good sole predictor of methanogenic activity, but may predict the extent of crude oil biodegradation. However, when the shallow, highly biodegraded, low salinity wells were excluded from the statistical analysis, no environmental parameters could explain the differences in microbial community structure. This suggests that the microbial community structure of the 5 shallow, up-dip wells was different than the 17 deeper, down-dip wells. Also, the 17 down-dip wells had statistically similar microbial communities despite significant changes in environmental parameters between oil fields. Together, this implies that no single microbial population is a reliable indicator of a reservoir's ability to degrade crude oil to methane, and that geochemistry may be a more important indicator for selecting a reservoir suitable for microbial enhancement of natural gas generation.

Biodegradation of marine oil spills in the Arctic with a Greenland perspective.

PubMed

Vergeynst, Leendert; Wegeberg, Susse; Aamand, Jens; Lassen, Pia; Gosewinkel, Ulrich; Fritt-Rasmussen, Janne; Gustavson, Kim; Mosbech, Anders

2018-06-01

New economic developments in the Arctic, such as shipping and oil exploitation, bring along unprecedented risks of marine oil spills. Microorganisms have played a central role in degrading and reducing the impact of the spilled oil during past oil disasters. However, in the Arctic, and in particular in its pristine areas, the self-cleaning capacity and biodegradation potential of the natural microbial communities have yet to be uncovered. This review compiles and investigates the current knowledge with respect to environmental parameters and biochemical constraints that control oil biodegradation in the Arctic. Hereby, seawaters off Greenland are considered as a case study. Key factors for biodegradation include the bioavailability of hydrocarbons, the presence of hydrocarbon-degrading bacteria and the availability of nutrients. We show how these key factors may be influenced by the physical oceanographic conditions in seawaters off Greenland and other environmental parameters including low temperature, sea ice, sunlight regime, suspended sediment plumes and phytoplankton blooms that characterize the Arctic. Based on the acquired insights, a first qualitative assessment of the biodegradation potential in seawaters off Greenland is presented. In addition to the most apparent Arctic characteristics, such as low temperature and sea ice, the impact of typical Arctic features such as the oligotrophic environment, poor microbial adaptation to hydrocarbon degradation, mixing of stratified water masses, and massive phytoplankton blooms and suspended sediment plumes merit to be topics of future investigation. Copyright © 2018 Elsevier B.V. All rights reserved.

Environmental biodegradation of haloarchaea-produced poly(3-hydroxybutyrate-co-3-hydroxyvalerate) in activated sludge.

PubMed

Liu, Xiao-Bin; Wu, Lin-Ping; Hou, Jing; Chen, Jun-Yu; Han, Jing; Xiang, Hua

2016-08-01

Novel poly(3-hydroxybutyrate-co-3-hydroxyvalerate) (PHBHV) copolymers produced by haloarchaea are excellent candidate biomaterials. However, there is no report hitherto focusing on the biodegradation of PHBHV synthesized by haloarchaea. In this study, an environmental biodegradation of haloarchaea-produced PHBHV films, with 10~60 mol% 3-hydroxyvalerate (3HV) composition and different microchemical structures, was studied in nutrition-depleted activated sludge. The changes in mass, molar mass, chemical composition, thermal properties, and surface morphology were monitored. The mass and molar mass of each film decreased significantly, while the PHA monomer composition remained unchanged with time. Interestingly, the sample of random copolymer PHBHV-2 (R-PHBHV-2) (3HV, 30 mol%) had the lowest crystallinity and was degraded faster than R-PHBHV-3 containing the highest 3HV content or the higher-order copolymer PHBHV-1 (O-PHBHV-1) possessing the highest surface roughness. The order of biodegradation rate was in the opposite trend to the degree of crystallizability of the films. Meanwhile, thermal degradation temperature of most films decreased after biodegradation. Additionally, the surface erosion of films was confirmed by scanning electron microscopy. The dominant bacteria probably responsible for the degradation process were identified in the activated sludge. It was inferred that the degradation rate of haloarchaea-produced PHBHV films mainly depended on sample crystallinity, which was determined by monomer composition and microchemical structure and in turn strongly influenced surface morphology.

Effect of test concentration in the ready biodegradability test for chemical substances: Improvement of OECD test guideline 301C.

PubMed

Nabeoka, Ryosuke; Taruki, Masanori; Kayashima, Takakazu; Yoshida, Tomohiko; Kameya, Takashi

2016-01-01

In Japan, understanding the environmental persistence of chemicals is very important for risk assessment, and ready biodegradability tests are mainly conducted according to the Organisation for Economic Co-operation and Development test guideline 301C. However, the highest test concentration specified in test guideline 301C, 100 mg/L, may cause microbial toxicity and incomplete biodegradation. The authors performed test guideline 301C tests at test concentrations of 30 mg/L for 13 substances that were readily biodegradable in ready biodegradability tests but not in test guideline 301C tests. Of the 5 substances with potential to cause microbial toxicity at 100 mg/L, the percentage of biodegradation of sodium dimethyldithiocarbamate, 4-chloro-3-cresol (CC), thymol (THY), and p-tert-butyl-α-methylbenzenepropionaldehyde measured by biochemical oxygen demand (BOD) increased in the test guideline 301C test at 30 mg/L, suggesting a reduction in toxicity effects. Furthermore, CC and THY met the criteria for ready biodegradability, which are more than 60% of biodegradation by BOD and a 10-d window. Of the 8 substances with a low potential for causing microbial toxicity at 100 mg/L, the percentage of biodegradation of only 2-(diethylamino)ethanol increased in the test guideline 301C test at 30 mg/L. Employing a lower test concentration in the standard test guideline 301C test will contribute to improvement of consistency between results of a test guideline 301C test and other ready biodegradability tests. © 2015 SETAC.

Biodegradability of fluorinated fire-fighting foams in water.

PubMed

Bourgeois, A; Bergendahl, J; Rangwala, A

2015-07-01

Fluorinated fire-fighting foams may be released into the environment during fire-fighting activities, raising concerns due to the potential environmental and health impacts for some fluorinated organics. The current study investigated (1) the biodegradability of three fluorinated fire-fighting foams, and (2) the applicability of current standard measures used to assess biodegradability of fluorinated fire-fighting foams. The biodegradability of three fluorinated fire-fighting foams was evaluated using a 28-day dissolved organic carbon (DOC) Die-Away Test. It was found that all three materials, diluted in water, achieved 77-96% biodegradability, meeting the criteria for "ready biodegradability". Defluorination of the fluorinated organics in the foam during biodegradation was measured using ion chromatography. It was found that the fluorine liberated was 1-2 orders of magnitude less than the estimated initial amount, indicating incomplete degradation of fluorinated organics, and incomplete CF bond breakage. Published biodegradability data may utilize biochemical oxygen demand (BOD), chemical oxygen demand (COD), and total organic carbon (TOC) metrics to quantify organics. COD and TOC of four fluorinated compounds were measured and compared to the calculated carbon content or theoretical oxygen demand. It was found that the standard dichromate-based COD test did not provide an accurate measure of fluorinated organic content. Thus published biodegradability data using COD for fluorinated organics quantification must be critically evaluated for validity. The TOC measurements correlated to an average of 91% of carbon content for the four fluorinated test substances, and TOC is recommended for use as an analytical parameter in fluorinated organics biodegradability tests. Copyright © 2015 Elsevier Ltd. All rights reserved.

Ultimate biodegradability and ecotoxicity of orally administered antidiabetic drugs.

PubMed

Markiewicz, Marta; Jungnickel, Christian; Stolte, Stefan; Białk-Bielińska, Anna; Kumirska, Jolanta; Mrozik, Wojciech

2017-07-05

Hypoglycaemic pharmaceuticals are recently more and more frequently detected in the environment. In our previous study, we have shown that even though many of them undergo significant primary degradation some are transformed to stable products or undergo such transformation that a large part of the structure is still preserved. One of the main routes of elimination from wastewaters or surface waters is biodegradation and a lack thereof leads to accumulation in the environment. Within this work we tested the ultimate biodegradability of six oral antidiabetics: metformin and its main metabolite guanylurea, acarbose, glibenclamide, gliclazide, glimepiride and repaglinide. We also compared the experimental results obtained in this and accompanying work with models designed to predict biodegradability and showed that these models are only moderately successful. Additionally, we examined these compounds in acute Daphnia magna test to check if they might pose an ecotoxicological threat. Combining the results of biodegradability and toxicity tests allows a preliminary assessment of their potential environmental impact. Copyright © 2017 Elsevier B.V. All rights reserved.

Prediction of chemical biodegradability using support vector classifier optimized with differential evolution.

PubMed

Cao, Qi; Leung, K M

2014-09-22

Reliable computer models for the prediction of chemical biodegradability from molecular descriptors and fingerprints are very important for making health and environmental decisions. Coupling of the differential evolution (DE) algorithm with the support vector classifier (SVC) in order to optimize the main parameters of the classifier resulted in an improved classifier called the DE-SVC, which is introduced in this paper for use in chemical biodegradability studies. The DE-SVC was applied to predict the biodegradation of chemicals on the basis of extensive sample data sets and known structural features of molecules. Our optimization experiments showed that DE can efficiently find the proper parameters of the SVC. The resulting classifier possesses strong robustness and reliability compared with grid search, genetic algorithm, and particle swarm optimization methods. The classification experiments conducted here showed that the DE-SVC exhibits better classification performance than models previously used for such studies. It is a more effective and efficient prediction model for chemical biodegradability.

Evaluation of biomass production in unleaded gasoline and BTEX-fed batch reactors.

PubMed

Acuna-Askar, K; Englande, A J; Ramirez-Medrano, A; Coronado-Guardiola, J E; Chavez-Gomez, B

2003-01-01

BTEX removal under aerobic conditions by unleaded gasoline acclimated biomass and BTEX acclimated biomass, and the effect of surfactant on BTEX biodegradation were evaluated. The effect of BTEX concentration as the sole source of carbon for biomass acclimation and the effect of yeast extract on cell growth in unleaded gasoline-fed reactors were also evaluated. For the unleaded gasoline acclimated biomass, benzene was shown the most recalcitrant among all BTEX, followed by o-xylene and toluene with 16-23%, 35-41% and 57-69% biodegradation, respectively. Ethylbenzene was consistently the fastest BTEX chemical removed with 99% biodegradation for the four bioreactor acclimated biomasses tested. For the 1,200 ppm BTEX acclimated biomass, benzene showed the highest removal efficiency (99%) among the four biomass environmental conditions tested, along with 99% toluene and 99% ethylbenzene biodegradation. O-xylene showed 92-94% removal. In all bioassays tested Tergitol NP-10 was fully removed, and did not have a substantial effect on BTEX biodegradation at the end of a 10-day evaluation.

Systemic approaches to biodegradation.

PubMed

Trigo, Almudena; Valencia, Alfonso; Cases, Ildefonso

2009-01-01

Biodegradation, the ability of microorganisms to remove complex chemicals from the environment, is a multifaceted process in which many biotic and abiotic factors are implicated. The recent accumulation of knowledge about the biochemistry and genetics of the biodegradation process, and its categorization and formalization in structured databases, has recently opened the door to systems biology approaches, where the interactions of the involved parts are the main subject of study, and the system is analysed as a whole. The global analysis of the biodegradation metabolic network is beginning to produce knowledge about its structure, behaviour and evolution, such as its free-scale structure or its intrinsic robustness. Moreover, these approaches are also developing into useful tools such as predictors for compounds' degradability or the assisted design of artificial pathways. However, it is the environmental application of high-throughput technologies from the genomics, metagenomics, proteomics and metabolomics that harbours the most promising opportunities to understand the biodegradation process, and at the same time poses tremendous challenges from the data management and data mining point of view.

The enhanced stability and biodegradation of dispersed crude oil droplets by Xanthan Gum as an additive of chemical dispersant.

PubMed

Wang, Aiqin; Li, Yiming; Yang, Xiaolong; Bao, Mutai; Cheng, Hua

2017-05-15

It is necessary for chemical dispersant to disperse oil effectively and maintain the stability of oil droplets. In this work, Xanthan Gum (XG) was used as an environmentally friendly additive in oil dispersant formulation to enhance the stability and biodegradation of dispersed crude oil droplets. When XG was used together with chemical dispersant 9500A, the dispersion effectiveness of crude oil in artificial sea water (ASW) and the oil droplet stability were both greatly enhanced. In the presence of XG, lower concentration of 9500A was needed to achieve the effective dispersion and stabilization. In addition to the enhancement of dispersion and stabilization, it was found that the biodegradation rate of crude oil by bacteria was dramatically enhanced when a mixture of 9500A and XG was used as a dispersant. Because of the low environmental impact of XG, this would be a potential way to formulate the dispersant with lower toxicity. Copyright © 2017 Elsevier Ltd. All rights reserved.

Environmental fate and effect of biodegradable electro-spun scaffolds (biomaterial)-a case study.

PubMed

Irizar, A; Amorim, M J B; Fuller, K P; Zeugolis, D I; Scott-Fordsmand, J J

2018-04-30

Poly-ε-caprolactone (PCL) based medical devices are increasingly produced and thus, their presence in the environment is likely to increase. The present study analysed the biodegradation of PCL electro-spun scaffolds (alone) and PCL electro-spun scaffolds coated with human recombinant (hR) collagen and Bovine Achilles tendon (BAT) collagen in sewage sludge and in soil. Additionally, an eco-toxicological test with the model organism Enchytraeus crypticus was performed to assess environmental hazard of the produced materials in soils. The electro-spun scaffolds were exposed to activated sludge and three different soils for various time periods (0-7-14-21-28-56-180 days); subsequently the degradation was determined by weight loss and microscopical analysis. Although no toxicity occurred in terms of Enchytraeus crypticus reproduction, our data indicate that biodegradation was dependent on the coating of the material and exposure condition. Further, only partial PCL decomposition was possible in sewage treatment plants. Collectively, these data indicate that electro-spun PCL scaffolds are transferred to amended soils.

Blending of Low-Density Polyethylene and Poly-Lactic Acid with Maleic Anhydride as A Compatibilizer for Better Environmentally Food-Packaging Material

NASA Astrophysics Data System (ADS)

Setiawan, A. H.; Aulia, F.

2017-05-01

The common conventional food packaging materialsare using a thin layer plastic or film, which is made of a synthetic polymer, such as Low-Density Poly Ethylene (LDPE). However, the use of these polymers hasan adverse impact on the environment, because the synthetic polymersare difficult to degrade naturally. Poly-Lactic Acid (PLA) is a biodegradable polymer that can be substituted to synthetic polymers. Since LDPE and PLA have a difference in polarity, therefore the first step of research is to graft them with maleic anhydride (MAH) for increasing the properties of its miscibility. The interaction between them is confirmed by FTIR; whereas the environment issueis characterized by the water adsorption and biodegradability. The FTIR spectra indicated that there had been an interaction between LDPE and MAH and LDPE/LDPE-g-MAH/PLA blend. Increasing PLA content in the blend affected to the increasing in their water absorption and biodegradable. Poly-blend with 20% PLA content was the optimum composition for environmentally food packaging.

Recent state-of-the-art of biodegradable scale inhibitors for cooling-water treatment applications (Review)

NASA Astrophysics Data System (ADS)

Popov, K. I.; Kovaleva, N. E.; Rudakova, G. Ya.; Kombarova, S. P.; Larchenko, V. E.

2016-02-01

Scale formation is a challenge worldwide. Recently, scale inhibitors represent the best solution of this problem. The polyaminocarboxylic acids have been the first to be successfully applied in the field, although their efficacy was rather low. The next generation was developed on the grounds of polyphosphonic acids. The main disadvantage of these is associated with low biodegradation level. Polyacrylate-based phosphorous free inhibitors proposed as an alternative to phosphonates all also had low biodegradability. Thus, the main trend of recent R&D is the development of a new generation: environmentally friendly biodegradable scale inhibitors. The recent state of the word and domestic scale inhibitors markets is considered, the main industrial inhibitors manufacturers and marketed substances, as well as the general trends of R&D in the field, are characterized. It is demonstrated that most research is focused on biodegradable polymers and on phosponates with low phosphorus content, as well as on implementation of biodegradable fragments into polyacrylate matrixes for biodegradability enhancement. The problem of research results comparability is indicated along with domestic-made inhibitors quality and the gaps in scale inhibition mechanism. The actuality of fluorescent indicator fragment implementation into the scale inhibitor molecule for the better reagent monitoring in a cooling water system is specially emphasized.

Application of micronucleus test and comet assay to evaluate BTEX biodegradation.

PubMed

Mazzeo, Dânia Elisa Christofoletti; Matsumoto, Silvia Tamie; Levy, Carlos Emílio; de Angelis, Dejanira de Franceschi; Marin-Morales, Maria Aparecida

2013-01-01

The BTEX (benzene, toluene, ethylbenzene and xylene) mixture is an environmental pollutant that has a high potential to contaminate water resources, especially groundwater. The bioremediation process by microorganisms has often been used as a tool for removing BTEX from contaminated sites. The application of biological assays is useful in evaluating the efficiency of bioremediation processes, besides identifying the toxicity of the original contaminants. It also allows identifying the effects of possible metabolites formed during the biodegradation process on test organisms. In this study, we evaluated the genotoxic and mutagenic potential of five different BTEX concentrations in rat hepatoma tissue culture (HTC) cells, using comet and micronucleus assays, before and after biodegradation. A mutagenic effect was observed for the highest concentration tested and for its respective non-biodegraded concentration. Genotoxicity was significant for all non-biodegraded concentrations and not significant for the biodegraded ones. According to our results, we can state that BTEX is mutagenic at concentrations close to its water solubility, and genotoxic even at lower concentrations, differing from some described results reported for the mixture components, when tested individually. Our results suggest a synergistic effect for the mixture and that the biodegradation process is a safe and efficient methodology to be applied at BTEX-contaminated sites. Copyright © 2012 Elsevier Ltd. All rights reserved.

Structure/activity relationships for biodegradability and their role in environmental assessment

DOE Office of Scientific and Technical Information (OSTI.GOV)

Boethling, R.S.

1994-12-31

Assessment of biodegradability is an important part of the review process for both new and existing chemicals under the Toxic Substances Control Act. It is often necessary to estimate biodegradability because experimental data are unavailable. Structure/biodegradability relationships (SBR) are a means to this end. Quantitative SBR have been developed, but this approach has not been very useful because they apply only to a few narrowly defined classes of chemicals. In response to the need for more widely applicable methods, multivariate analysis has been used to develop biodegradability classification models. For example, recent efforts have produced four new models. Two calculatemore » the probability of rapid biodegradation and can be used for classification; the other two models allow semi-quantitative estimation of primary and ultimate biodegradation rates. All are based on multiple regressions against 36 preselected substructures plus molecular weight. Such efforts have been fairly successful by statistical criteria, but in general are hampered by a lack of large and consistent datasets. Knowledge-based expert systems may represent the next step in the evolution of SBR. In principle such systems need not be as severely limited by imperfect datasets. However, the codification of expert knowledge and reasoning is a critical prerequisite. Results of knowledge acquisition exercises and modeling based on them will also be described.« less

Biodegradation of clotrimazole and modification of cell properties after metabolic stress and upon addition of saponins.

PubMed

Pacholak, A; Simlat, J; Zgoła-Grześkowiak, A; Kaczorek, E

2018-06-20

Azole fungicides constitute an extensive group of potential emerging pollutants which can be found in natural environment. This study focuses on the biodegradation of clotrimazole and the characterization of cell surface properties of microorganisms capable of degradation of this compound. The influence of long-term contact of bacteria with clotrimazole and the impact of the addition of Saponaria officinalis extract on cell surface modification was also checked. The biodegradation of clotrimazole did not exceed 70%. The presence of plant extract increased biodegradation of fungicide. The cells metabolic activity after one-month exposure to clotrimazole was the highest for each tested strain. Moreover, metabolic stress led to a strong modification of cell surface properties. The results are promising for determining the impact of clotrimazole on environmental microorganisms. Copyright © 2018 Elsevier Inc. All rights reserved.

Biodegradable and bio-based polymers: future prospects of eco-friendly plastics.

PubMed

Iwata, Tadahisa

2015-03-09

Currently used plastics are mostly produced from petrochemical products, but there is a growing demand for eco-friendly plastics. The use of bio-based plastics, which are produced from renewable resources, and biodegradable plastics, which are degraded in the environment, will lead to a more sustainable society and help us solve global environmental and waste management problems. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

BioSurfDB: knowledge and algorithms to support biosurfactants and biodegradation studies

PubMed Central

Oliveira, Jorge S.; Araújo, Wydemberg; Lopes Sales, Ana Isabela; de Brito Guerra, Alaine; da Silva Araújo, Sinara Carla; de Vasconcelos, Ana Tereza Ribeiro; Agnez-Lima, Lucymara F.; Freitas, Ana Teresa

2015-01-01

Crude oil extraction, transportation and use provoke the contamination of countless ecosystems. Therefore, bioremediation through surfactants mobilization or biodegradation is an important subject, both economically and environmentally. Bioremediation research had a great boost with the recent advances in Metagenomics, as it enabled the sequencing of uncultured microorganisms providing new insights on surfactant-producing and/or oil-degrading bacteria. Many research studies are making available genomic data from unknown organisms obtained from metagenomics analysis of oil-contaminated environmental samples. These new datasets are presently demanding the development of new tools and data repositories tailored for the biological analysis in a context of bioremediation data analysis. This work presents BioSurfDB, www.biosurfdb.org, a curated relational information system integrating data from: (i) metagenomes; (ii) organisms; (iii) biodegradation relevant genes; proteins and their metabolic pathways; (iv) bioremediation experiments results, with specific pollutants treatment efficiencies by surfactant producing organisms; and (v) a biosurfactant-curated list, grouped by producing organism, surfactant name, class and reference. The main goal of this repository is to gather information on the characterization of biological compounds and mechanisms involved in biosurfactant production and/or biodegradation and make it available in a curated way and associated with a number of computational tools to support studies of genomic and metagenomic data. Database URL: www.biosurfdb.org PMID:25833955

POLLUTION PREVENTION AND ENHANCEMENT OF BIODEGRADABILITY VIA ISOMER ELIMINATION IN CONSUMER PRODUCTS

EPA Science Inventory

The purpose of this project is to develop novel methodologies for the analysis and detection of chiral environmental contaminants. Conventional analytical techniques do not discriminate between enantiomers. By using newly developed enantioselective methods, the environmental pers...

Deterioration pattern of six biodegradable, potentially low-environmental impact mulches in field conditions.

PubMed

Moreno, Marta M; González-Mora, Sara; Villena, Jaime; Campos, Juan A; Moreno, Carmen

2017-09-15

Polyethylene plastic mulches are widely used in agriculture due to the countless advantages they have. However, the environmental problems associated with their use have led us to look for alternative mulch materials which degrade naturally and quickly, impact the environment less and function satisfactorily. To this end, biodegradable plastics and paper mulches are being used, but aspects related to their degradation should be studied more in-depth. This work provides the deterioration pattern of six biodegradable mulch materials (i.e. vegetable starch, polylactic acid plastic films or paper mulches) in horticultural crop in the edaphoclimatic conditions of Central Spain in two situations: over the lifetime of the mulches and after being incorporated into the soil. In the first situation, the deterioration levels were evaluated by recording the puncture resistance, weight and area covered in the above-soil and the in-soil part, and after soil incorporation by the number of fragments, their surfaces and weight. In the above-soil part, biodegradable plastics experienced further deterioration, particularly with no crop, while the paper mulch remained practically intact. However, the in-soil paper experienced complete and rapid degradation. At 200 days after soil incorporation, mulch residues were scarce, with the environmental effects it entails. These findings offer practical implications regarding the type of crop. The measurement of the surface covered, rather than the weight, was shown to be a more reliable indicator of the degradation of mulches. Furthermore, visual estimation was found to underestimate the functionality of mulches in comparison to that of the measurement of the surface covered. Copyright © 2017 Elsevier Ltd. All rights reserved.

Effect of interlayer cations of montmorillonite on the biodegradation and adsorption of crude oil polycyclic aromatic compounds.

PubMed

Ugochukwu, Uzochukwu C; Manning, David A C; Fialips, Claire I

2014-09-01

Cation exchange capacity, surface acidity and specific surface area are surface properties of clay minerals that make them act as catalysts or supports in most biogeochemical processes hence making them play important roles in environmental control. However, the role of homoionic clay minerals during the biodegradation of polycyclic aromatic compounds is not well reported. In this study, the effect of interlayer cations of montmorillonites in the removal of some crude oil polycyclic aromatic compounds during biodegradation was investigated in aqueous clay/oil microcosm experiments with a hydrocarbon degrading microorganism community. The homoionic montmorillonites were prepared via cation exchange reactions by treating the unmodified montmorillonite with the relevant metallic chloride. The study indicated that potassium-montmorillonite and zinc-montmorillonite did not enhance the biodegradation of the polycyclic aromatic hydrocarbons whereas calcium-montmorillonite, and ferric-montmorillonite enhanced their biodegradation significantly. Adsorption of polycyclic aromatic hydrocarbons was significant during biodegradation with potassium- and zinc-montmorillonite where there was about 45% removal of the polycyclic aromatic compounds by adsorption in the experimental microcosm containing 5:1 ratio (w/w) of clay to oil. Copyright © 2014 Elsevier Ltd. All rights reserved.

Fringe-controlled biodegradation under dynamic conditions: Quasi 2-D flow-through experiments and reactive-transport modeling

NASA Astrophysics Data System (ADS)

Eckert, Dominik; Kürzinger, Petra; Bauer, Robert; Griebler, Christian; Cirpka, Olaf A.

2015-01-01

Biodegradation in contaminated aquifers has been shown to be most pronounced at the fringe of contaminant plumes, where mixing of contaminated water and ambient groundwater, containing dissolved electron acceptors, stimulates microbial activity. While physical mixing of contaminant and electron acceptor by transverse dispersion has been shown to be the major bottleneck for biodegradation in steady-state plumes, so far little is known on the effect of flow and transport dynamics (caused, e.g., by a seasonally fluctuating groundwater table) on biodegradation in these systems. Towards this end we performed experiments in quasi-two-dimensional flow-through microcosms on aerobic toluene degradation by Pseudomonas putida F1. Plume dynamics were simulated by vertical alteration of the toluene plume position and experimental results were analyzed by reactive-transport modeling. We found that, even after disappearance of the toluene plume for two weeks, the majority of microorganisms stayed attached to the sediment and regained their full biodegradation potential within two days after reappearance of the toluene plume. Our results underline that besides microbial growth, also maintenance and dormancy are important processes that affect biodegradation performance under transient environmental conditions and therefore deserve increased consideration in future reactive-transport modeling.

Anaerobic biodegradability of alkylphenols and fuel oxygenates in the presence of alternative electron acceptors.

PubMed

Puig-Grajales, L; Tan, N G; van der Zee, F; Razo-Flores, E; Field, J A

2000-11-01

Alkylphenols and fuel oxygenates are important environmental pollutants produced by the petrochemical industry. A batch biodegradability test was conducted with selected ortho-substituted alkylphenols (2-cresol, 2,6-dimethylphenol and 2-ethylphenol), fuel oxygenates (methyl tert-butyl ether, ethyl tert-butyl ether and tert-amylmethyl ether) and tert-butyl alcohol (TBA) as model compounds. The ortho-substituted alkylphenols were not biodegraded after 100 days of incubation under methanogenic, sulfate-, or nitrate-reducing conditions. However, biodegradation of 2-cresol and 2-ethylphenol (150 mg l(-1)) was observed in the presence of Mn (IV) as electron acceptor. The biodegradation of these two compounds took place in less than 15 days and more than 90% removal was observed for both compounds. Mineralization was indicated since no UV-absorbing metabolites accumulated after 23 days of incubation. These alkylphenols were also slowly chemically oxidized by Mn (IV). No biodegradation of fuel oxygenates or TBA (1 g l(-1)) was observed after 80 or more days of incubation under methanogenic, Fe (III)-, or Mn (IV)-reducing conditions, suggesting that these compounds are recalcitrant under anaerobic conditions. The fuel oxygenates caused no toxicity towards acetoclastic methanogens activity in anaerobic granular sludge.

Aquatic toxicity and biodegradability of advanced cationic surfactant APA-22 compatible with the aquatic environment.

PubMed

Yamane, Masayuki; Toyo, Takamasa; Inoue, Katsuhisa; Sakai, Takaya; Kaneko, Youhei; Nishiyama, Naohiro

2008-01-01

Cationic surfactant is a chemical substance used in hair conditioner, fabric softener and other household products. By investigating the relationship between the aquatic toxicity and the chemical structures of two types of mono alkyl cationic surfactants, alkyl trimethylammonium salts and alkyl dimethylamine salts, we have found that the C22 alkyl chain length is effective to reduce the toxicity. Besides, we have recognized that the amidopropyl functional group contributes to the enhanced biodegradability by investigating the biodegradation trend of (alkylamidopropyl)dimethylamine salt (alkyl chain length: C18). Based on these findings, we have developed mono alkyl cationic surfactant called APA-22, N-[3-(dimethylamino)propyl]docosanamide salt. APA-22 is formed by the C22 alkyl chain, amidopropyl functional group and di-methyltertiary amine group. We evaluated the aerobic and anaerobic biodegradability of APA-22 by two standard methods (OECD Test Guideline 301B and ECETOC technical document No.28) and found that this substance was degraded rapidly in both conditions. The toxicity to algae, invertebrate and fish of this substance are evaluated by using OECD Test Guideline 201, 202 and 203, respectively. All acute toxicity values are >1 mg/L, which indicates that environmental toxicity of this substance is relatively less toxic to aquatic organism. In addition, we estimated the biodegradation pathway of APA-22 and observed the complete disappearance of APA-22 and its intermediates during the test periods. Based on the environmental data provided above, we concluded that APA22 is more compatible with the aquatic environment compared to other cationic surfactants with mono long alkyl chain.

Biodegradation Kinetics of 1,4-Dioxane in Chlorinated Solvent Mixtures.

PubMed

Zhang, Shu; Gedalanga, Phillip B; Mahendra, Shaily

2016-09-06

This study investigated the impacts of individual chlorinated solvents and their mixtures on aerobic 1,4-dioxane biodegradation by Pseudonocardia dioxanivorans CB1190. The established association of these co-occurring compounds suggests important considerations for their respective biodegradation processes. Our kinetics and mechanistic studies demonstrated that individual solvents inhibited biodegradation of 1,4-dioxane in the following order: 1,1-dichloroethene (1,1-DCE) > cis-1,2-diochloroethene (cDCE) > trichloroethene (TCE) > 1,1,1-trichloroethane (TCA). The presence of 5 mg L(-1) 1,1-DCE completely inhibited 1,4-dioxane biodegradation. Subsequently, we determined that 1,1-DCE was the strongest inhibitor of 1,4-dioxane biodegradation by bacterial pure cultures exposed to chlorinated solvent mixtures as well as in environmental samples collected from a site contaminated with chlorinated solvents and 1,4-dioxane. Inhibition of 1,4-dioxane biodegradation rates by chlorinated solvents was attributed to delayed ATP production and down-regulation of both 1,4-dioxane monooxygenase (dxmB) and aldehyde dehydrogenase (aldH) genes. Moreover, increasing concentrations of 1,1-DCE and cis-1,2-DCE to 50 mg L(-1) respectively increased 5.0-fold and 3.5-fold the expression of the uspA gene encoding a universal stress protein. In situ natural attenuation or enhanced biodegradation of 1,4-dioxane is being considered for contaminated groundwater and industrial wastewater, so these results will have implications for selecting 1,4-dioxane bioremediation strategies at sites where chlorinated solvents are present as co-contaminants.

Microbial Enzymatic Degradation of Biodegradable Plastics.

PubMed

Roohi; Bano, Kulsoom; Kuddus, Mohammed; Zaheer, Mohammed R; Zia, Qamar; Khan, Mohammed F; Ashraf, Ghulam Md; Gupta, Anamika; Aliev, Gjumrakch

2017-01-01

The renewable feedstock derived biodegradable plastics are important in various industries such as packaging, agricultural, paper coating, garbage bags and biomedical implants. The increasing water and waste pollution due to the available decomposition methods of plastic degradation have led to the emergence of biodegradable plastics and biological degradation with microbial (bacteria and fungi) extracellular enzymes. The microbes utilize biodegradable polymers as the substrate under starvation and in unavailability of microbial nutrients. Microbial enzymatic degradation is suitable from bioremediation point of view as no waste accumulation occurs. It is important to understand the microbial interaction and mechanism involved in the enzymatic degradation of biodegradable plastics under the influence of several environmental factors such as applied pH, thermo-stability, substrate molecular weight and/or complexity. To study the surface erosion of polymer film is another approach for hydrolytic degradation characteristion. The degradation of biopolymer is associated with the production of low molecular weight monomer and generation of carbon dioxide, methane and water molecule. This review reported the degradation study of various existing biodegradable plastics along with the potent degrading microbes (bacteria and fungi). Patents available on plastic biodegradation with biotechnological significance is also summarized in this paper. This paper assesses that new disposal technique should be adopted for the degradation of polymers and further research is required for the economical production of biodegradable plastics along with their enzymatic degradation. Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.org.

Interaction between Carbon Nanotubes and Aromatic Hydrocarbon-degrading Microbes and its Effect on Carbon Nanotubes Transformation

NASA Astrophysics Data System (ADS)

You, Y.; Wang, L.; Poulson, S.; Wang, X.; Xing, B.; Yang, Y.

2015-12-01

Due to their unique electrical, optical and mechanical properties, carbon nanotubes (CNTs) have been substantially produced and widely applied during the past decades, leading to their increased probability of entering the environment. Some estimation suggests that CNTs are accumulated in agricultural systems with their soil concentration increasing by 0.4-157 ng/kg/year. This has raised concerns about environmental impacts of these emerging contaminants including their ecotoxicity. Meanwhile, transformation of CNTs in the environment can significantly affect their transport, bioavailability and thereby ecotoxicity. So far, environmental biodegradation of CNTs remains obscure. Given the high diversity of soil microorganisms and their metabolic potentials, it is important to investigate microbial biodegradation of CNTs under various environmental conditions. This study focuses on an aromatic hydrocarbon-degrading bacterium, Mycobacterium vanbaalenii PYR-1, as a model microorganism capable of ring cleavage. We hypothesize that bacterial activities could transform CNTs to more hydrophilic forms, increasing their aqueous stability and environmental reactivity. We incubated M. vanbaalenii PYR-1 with 13C-labeded multiwall carbon nanotubes (MWCNTs) for 30 days, monitored δ13C in the system, characterized MWCNTs before and after the reaction, and compared the results with culture-negative controls. To investigate effects of various environmental conditions, including the presence of extracellular oxidative enzymes from white-rot fungi, additional experiments will be conducted and results compared will be compared among different setups. Moreover, we will measure adverse impacts of CNTs on the metabolic activities of M. vanbaalenii PYR-1, particularly its biodegradation of polycyclic aromatic hydrocarbons.

A new biodegradation prediction model specific to petroleum hydrocarbons.

PubMed

Howard, Philip; Meylan, William; Aronson, Dallas; Stiteler, William; Tunkel, Jay; Comber, Michael; Parkerton, Thomas F

2005-08-01

A new predictive model for determining quantitative primary biodegradation half-lives of individual petroleum hydrocarbons has been developed. This model uses a fragment-based approach similar to that of several other biodegradation models, such as those within the Biodegradation Probability Program (BIOWIN) estimation program. In the present study, a half-life in days is estimated using multiple linear regression against counts of 31 distinct molecular fragments. The model was developed using a data set consisting of 175 compounds with environmentally relevant experimental data that was divided into training and validation sets. The original fragments from the Ministry of International Trade and Industry BIOWIN model were used initially as structural descriptors and additional fragments were then added to better describe the ring systems found in petroleum hydrocarbons and to adjust for nonlinearity within the experimental data. The training and validation sets had r2 values of 0.91 and 0.81, respectively.

Modeling cutinase enzyme regulation in polyethylene terepthalate plastic biodegradation

NASA Astrophysics Data System (ADS)

Apri, M.; Silmi, M.; Heryanto, T. E.; Moeis, M. R.

2016-04-01

PET (Polyethylene terephthalate) is a plastic material that is commonly used in our daily life. The high production of PET and others plastics that can be up to three hundred million tons per year, is not matched by its degradation rate and hence leads to environmental pollution. To overcome this problem, we develop a biodegradation system. This system utilizes LC Cutinase enzyme produced by engineered escherichia coli bacteria to degrade PET. To make the system works efficaciously, it is important to understand the mechanism underlying its enzyme regulation. Therefore, we construct a mathematical model to describe the regulation of LC Cutinase production. The stability of the model is analyzed. We show that the designated biodegradation system can give an oscillatory behavior that is very important to control the amount of inclusion body (the miss-folded proteins that reduce the efficiency of the biodegradation system).

Modeling cutinase enzyme regulation in polyethylene terepthalate plastic biodegradation

DOE Office of Scientific and Technical Information (OSTI.GOV)

Apri, M., E-mail: m.apri@math.itb.ac.id; Silmi, M.; Heryanto, T. E.

PET (Polyethylene terephthalate) is a plastic material that is commonly used in our daily life. The high production of PET and others plastics that can be up to three hundred million tons per year, is not matched by its degradation rate and hence leads to environmental pollution. To overcome this problem, we develop a biodegradation system. This system utilizes LC Cutinase enzyme produced by engineered escherichia coli bacteria to degrade PET. To make the system works efficaciously, it is important to understand the mechanism underlying its enzyme regulation. Therefore, we construct a mathematical model to describe the regulation of LCmore » Cutinase production. The stability of the model is analyzed. We show that the designated biodegradation system can give an oscillatory behavior that is very important to control the amount of inclusion body (the miss-folded proteins that reduce the efficiency of the biodegradation system).« less

Optical and mechanical properties of UV-weathered biodegradable PHBV/PBAT nanocomposite films containing halloysite nanotubes

NASA Astrophysics Data System (ADS)

Scarfato, P.; Avallone, E.; Acierno, D.; Russo, P.

2014-05-01

Recently, the increasing use of plastics, stringent environmental issues and the awareness of the progressive reduction of available petrochemical resources have ever more guided the research interest towards the investigation and development of innovative materials intrinsically biodegradable or derived from renewable sources, and generally known as bio-based polymers. Amongst the biobased and biodegradable polymers, many investigations were reported in literature about a family of polyesters known as poly(hydroxyalkanoate)s (PHAs), one of whose most prevalent is poly(3-hydroxybutyrate-co-3-hydroxyvalerate) (PHBV). In this context, here we report the results of a photo-degradation study performed on biodegradable blown film samples based on a commercial grade PHBV/PBAT formulation. The films, subjected to photo-oxidative weathering in a climatic chamber under UV exposure, were systematically analysed in order to check the chemico-physical changes induced by the aging protocol, taking the as-produced films as the reference materials.

Biological removal of phenol from wastewaters: a mini review

NASA Astrophysics Data System (ADS)

Pradeep, N. V.; Anupama, S.; Navya, K.; Shalini, H. N.; Idris, M.; Hampannavar, U. S.

2015-06-01

Phenol and its derivatives are common water pollutants and include wide variety of organic chemicals. Phenol poisoning can occur by skin absorption, inhalation, ingestion and various other methods which can result in health effects. High exposures to phenol may be fatal to human beings. Accumulation of phenol creates toxicity both for flora and fauna. Therefore, removal of phenol is crucial to perpetuate the environment and individual. Among various treatment methods available for removal of phenols, biodegradation is environmental friendly. Biological methods are gaining importance as they convert the wastes into harmless end products. The present work focuses on assessment of biological removal (biodegradation) of phenol. Various factors influence the efficiency of biodegradation of phenol such as ability of the microorganism, enzymes involved, the mechanism of degradation and influencing factors. This study describes about the sources of phenol, adverse effects on the environment, microorganisms involved in the biodegradation (aerobic and anaerobic) and enzymes that polymerize phenol.

Modelling for environmental assessment of municipal solid waste landfills (part II: biodegradation).

PubMed

Garcia de Cortázar, Amaya Lobo; Lantarón, Javier Herrero; Fernández, Oscar Montero; Monzón, Iñaki Tejero; Lamia, Maria Fantelli

2002-12-01

The biodegradation module of a simulation program for municipal solid waste landfills (MODUELO) was developed. The biodegradation module carries out the balance of organic material starting with the results of the hydrologic simulation and the waste composition. It simulates the biologic reactions of hydrolysis of solids and the gasification of the dissolved biodegradable material. The results of this module are: organic matter (COD, BOD and elemental components such as carbon, hydrogen, nitrogen, oxygen, sulfur and ash), ammonium nitrogen generated with the gas and transported by the leachates and the potential rates of methane and carbon dioxide generation. The model was calibrated by using the general tendency curves of the pollutants recorded in municipal solid waste landfills, fitting the first part of them to available landfill data. Although the results show some agreement, further work is being done to make MODUELO a useful tool for real landfill simulation.

ENANTIOMER FRACTIONS OF CHLORDANE COMPOUNDS IN SEDIMENT SAMPLES FROM U.S. GEOLOGICAL SURVEY SITES IN LAKES, RIVERS, AND RESERVOIRS

EPA Science Inventory

More than 500 important environmental contaminants are chiral (having structures that are nonsuperimposible mirror images). Although enantiomer pairs have identical physical-chemical properties, their toxicity, biodegradation, and environmental fate often are different. Cyclo...

Environmental risk assessment of selected pharmaceuticals in Turkey.

PubMed

Oğuz, Merve; Mihçiokur, Hamdi

2014-07-01

In this study, environmental risks of selected pharmaceuticals were investigated to assess potential hazards. Ciprofloxacin, Clarithromycin, Cefuroxime axetil, antibiotics, Benzalkoniuman antiseptic, Paracetamol, an analgesic, and Naproxen, an anti-inflammatory, were selected due to their high rate of usage in Turkey. Ciprofloxacin was found to have the highest risk due to its high PEC/PNEC ratio (28.636). Benzalkonium, Paracetamol and Clarithromycin have a potential to cause environmental hazards. The biodegradation and biological concentration factors (BCF) of the drugs were also determined using EPA/STWIN and EPA/BCFWIN programs. The results illustrated that these pharmaceuticals are nonbiodegradable in wastewater treatment plants. The BCFs of Benzalkonium and Clarithromycin were found to be very high, 70.790 L/kg and 56.490 L/kg, respectively. It was suggested that alternative treatment methods other than biological ones should be investigated for these pharmaceuticals because of their low biodegradability. Also, unnecessary use of antibiotics is supposed to be discouraged to reduce environmental hazards. Copyright © 2014 Elsevier B.V. All rights reserved.

Anaerobic digestion of starch-polyvinyl alcohol biopolymer packaging: biodegradability and environmental impact assessment.

PubMed

Guo, M; Trzcinski, A P; Stuckey, D C; Murphy, R J

2011-12-01

The digestibility of a starch-polyvinyl alcohol (PVOH) biopolymer insulated cardboard coolbox was investigated under a defined anaerobic digestion (AD) system with key parameters characterized. Laboratory results were combined with industrial operational data to develop a site-specific life cycle assessment (LCA) model. Inoculated with active bacterial trophic groups, the anaerobic biodegradability of three starch-PVOH biopolymers achieved 58-62%. The LCA modeling showed that the environmental burdens of the starch-PVOH biopolymer packaging under AD conditions on acidification, eutrophication, global warming and photochemical oxidation potential were dominated by atmospheric emissions released from substrate degradation and fuel combustion, whereas energy consumption and infrastructure requirements were the causes of abiotic depletion, ozone depletion and toxic impacts. Nevertheless, for this bio-packaging, AD of the starch-PVOH biopolymer combined with recycling of the cardboard emerged as the environmentally superior option and optimization of the energy utilization system could bring further environmental benefits to the AD process. Copyright © 2011 Elsevier Ltd. All rights reserved.

Degradation of triclosan by environmental microbial consortia and by axenic cultures of microorganisms with concerns to wastewater treatment.

PubMed

Chen, Xijuan; Zhuang, Jie; Bester, Kai

2018-05-07

Triclosan is an antimicrobial agent, which is widely used in personal care products including toothpaste, soaps, deodorants, plastics, and cosmetics. Widespread use of triclosan has resulted in its release into wastewater, surface water, and soils and has received considerable attention in the recent years. It has been reported that triclosan is detected in various environmental compartments. Toxicity studies have suggested its potential environmental impacts, especially to aquatic ecosystems. To date, removal of triclosan has attracted rising attention and biodegradation of triclosan in different systems, such as axenic cultures of microorganisms, full-scale WWTPs, activated sludge, sludge treatment systems, sludge-amended soils, and sediments has been described. In this study, an extensive literature survey was undertaken, to present the current knowledge of the biodegradation behavior of triclosan and highlights the removal and transformation processes to help understand and predict the environmental fate of triclosan. Experiments at from lab-scale to full-scale field studies are shown and discussed.

Environmental fate and biodegradability of benzene derivatives as studied in a model aquatic ecosystem.

PubMed Central

Lu, P Y; Metcalf, R L

1975-01-01

A model aquatic ecosystem is devised for studying relatively volatile organic compounds and simulating direct discharge of chemical wastes into aquatic ecosystems. Six simple benzene derivatives (aniline, anisole, benzoic acid, chlorobenzene, nitrobenzene, and phthalic anhydride) and other important specialty chemicals: hexachlorobenzene, pentachlorophenol, 2,6-diethylaniline, and 3,5,6-trichloro-2-pyridinol were also chosen for study of environmental behavior and fate in the model aquatic ecosystem. Quantitative relationships of the intrinsic molecular properties of the environmental micropollutants with biological responses are established, e.g., water solubility, partition coefficient, pi constant, sigma constant, ecological magnification, biodegradability index, and comparative detoxication mechanisms, respectively. Water solubility, pi constant, and sigma constant are the most significant factors and control the biological responses of the food chain members. Water solubility and pi constant control the degree of bioaccumulation, and sigma constant limits the metabolism of the xenobiotics via microsomal detoxication enzymes. These highly significant correlations should be useful for predicting environmental fate of organic chemicals. PMID:1157796

Effect of alkyl side chain location and cyclicity on the aerobic biotransformation of naphthenic acids.

PubMed

Misiti, Teresa M; Tezel, Ulas; Pavlostathis, Spyros G

2014-07-15

Aerobic biodegradation of naphthenic acids is of importance to the oil industry for the long-term management and environmental impact of process water and wastewater. The effect of structure, particularly the location of the alkyl side chain as well as cyclicity, on the aerobic biotransformation of 10 model naphthenic acids (NAs) was investigated. Using an aerobic, mixed culture, enriched with a commercial NA mixture (NA sodium salt; TCI Chemicals), batch biotransformation assays were conducted with individual model NAs, including eight 8-carbon isomers. It was shown that NAs with a quaternary carbon at the α- or β-position or a tertiary carbon at the β- and/or β'-position are recalcitrant or have limited biodegradability. In addition, branched NAs exhibited lag periods and lower degradation rates than nonbranched or simple cyclic NAs. Two NA isomers used in a closed bottle, aerobic biodegradation assay were mineralized, while 21 and 35% of the parent compound carbon was incorporated into the biomass. The NA biodegradation probability estimated by two widely used models (BIOWIN 2 and 6) and a recently developed model (OCHEM) was compared to the biodegradability of the 10 model NAs tested in this study as well as other related NAs. The biodegradation probability estimated by the OCHEM model agreed best with the experimental data and was best correlated with the measured NA biodegradation rate.

Biodegradation of clofibric acid and identification of its metabolites.

PubMed

Salgado, R; Oehmen, A; Carvalho, G; Noronha, J P; Reis, M A M

2012-11-30

Clofibric acid (CLF) is the pharmaceutically active metabolite of lipid regulators clofibrate, etofibrate and etofyllinclofibrate, and it is considered both environmentally persistent and refractory. This work studied the biotransformation of CLF in aerobic sequencing batch reactors (SBRs) with mixed microbial cultures, monitoring the efficiency of biotransformation of CLF and the production of metabolites. The maximum removal achieved was 51% biodegradation (initial CLF concentration=2 mg L(-1)), where adsorption and abiotic removal mechanisms were shown to be negligible, showing that CLF is indeed biodegradable. Tests showed that the observed CLF biodegradation was mainly carried out by heterotrophic bacteria. Three main metabolites were identified, including α-hydroxyisobutyric acid, lactic acid and 4-chlorophenol. The latter is known to exhibit higher toxicity than the parent compound, but it did not accumulate in the SBRs. α-Hydroxyisobutyric acid and lactic acid accumulated for a period, where nitrite accumulation may have been responsible for inhibiting their degradation. A metabolic pathway for the biodegradation of CLF is proposed in this study. Copyright © 2012 Elsevier B.V. All rights reserved.

Challenges and opportunities of biodegradable plastics: A mini review.

PubMed

Rujnić-Sokele, Maja; Pilipović, Ana

2017-02-01

The concept of materials coming from nature with environmental advantages of being biodegradable and/or biobased (often referred to as bioplastics) is very attractive to the industry and to the consumers. Bioplastics already play an important role in the fields of packaging, agriculture, gastronomy, consumer electronics and automotive, but still they have a very low share in the total production of plastics (currently about 1% of the about 300 million tonnes of plastic produced annually). Biodegradable plastics are often perceived as the possible solution for the waste problem, but biodegradability is just an additional feature of the material to be exploited at the end of its life in specific terms, in the specific disposal environment and in a specific time, which is often forgotten. They should be used as a favoured choice for the applications that demand a cheap way to dispose of the item after it has fulfilled its job (e.g. for food packaging, agriculture or medical products). The mini-review presents the opportunities and future challenges of biodegradable plastics, regarding processing, properties and waste management options.

Biodegradation of o-Benzyl-p-Chlorophenol

PubMed Central

Swisher, R. D.; Gledhill, W. E.

1973-01-01

The extent of biodegradation of o-benzyl-p-chlorophenol, marketed as a germicide under the name Santophen® 1 (Monsanto Co.), in river water, sewage, and activated sludge was determined. Biodegradation was assessed by use of a colorimetric procedure for phenolic materials, carbon analysis, and CO2 evolution. In unacclimated river water, 0.1 mg of Santophen 1 per liter was degraded within 6 days. In sewage, 0.5 and 1.0 mg/liter levels of Santophen 1 were degraded in 1 day. Acclimated activated sludge achieved 80% biodegradation of 1.0 mg/liter Santophen 1 in 8 h and 100% in 24 h. When effluent from a semicontinuous activated sludge unit, acclimated to 20 mg of Santophen 1 per liter was used as the inoculum for the CO2 evolution procedure, 60% of the total theoretical CO2 was evolved from Santophen 1. Based on the results of these studies, indicating Santophen 1 to be readily biodegraded in at least four biological systems, the continued use of present levels of Santophen 1 should present no significant environmental problems. PMID:4356462

Biodegradation potential of MTBE in a fractured chalk aquifer under aerobic conditions in long-term uncontaminated and contaminated aquifer microcosms.

PubMed

Shah, Nadeem W; Thornton, Steven F; Bottrell, Simon H; Spence, Michael J

2009-01-26

The potential for aerobic biodegradation of MTBE in a fractured chalk aquifer is assessed in microcosm experiments over 450 days, under in situ conditions for a groundwater temperature of 10 degrees C, MTBE concentration between 0.1 and 1.0 mg/L and dissolved O2 concentration between 2 and 10 mg/L. Following a lag period of up to 120 days, MTBE was biodegraded in uncontaminated aquifer microcosms at concentrations up to 1.2 mg/L, demonstrating that the aquifer has an intrinsic potential to biodegrade MTBE aerobically. The MTBE biodegradation rate increased three-fold from a mean of 6.6+/-1.6 microg/L/day in uncontaminated aquifer microcosms for subsequent additions of MTBE, suggesting an increasing biodegradation capability, due to microbial cell growth and increased biomass after repeated exposure to MTBE. In contaminated aquifer microcosms which also contained TAME, MTBE biodegradation occurred after a shorter lag of 15 or 33 days and MTBE biodegradation rates were higher (max. 27.5 microg/L/day), probably resulting from an acclimated microbial population due to previous exposure to MTBE in situ. The initial MTBE concentration did not affect the lag period but the biodegradation rate increased with the initial MTBE concentration, indicating that there was no inhibition of MTBE biodegradation related to MTBE concentration up to 1.2 mg/L. No minimum substrate concentration for MTBE biodegradation was observed, indicating that in the presence of dissolved O2 (and absence of inhibitory factors) MTBE biodegradation would occur in the aquifer at MTBE concentrations (ca. 0.1 mg/L) found at the front of the ether oxygenate plume. MTBE biodegradation occurred with concomitant O2 consumption but no other electron acceptor utilisation, indicating biodegradation by aerobic processes only. However, O2 consumption was less than the stoichiometric requirement for complete MTBE mineralization, suggesting that only partial biodegradation of MTBE to intermediate organic metabolites occurred. The availability of dissolved O2 did not affect MTBE biodegradation significantly, with similar MTBE biodegradation behaviour and rates down to ca. 0.7 mg/L dissolved O2 concentration. The results indicate that aerobic MTBE biodegradation could be significant in the plume fringe, during mixing of the contaminant plume and uncontaminated groundwater and that, relative to the plume migration, aerobic biodegradation is important for MTBE attenuation. Moreover, should the groundwater dissolved O2 concentration fall to zero such that MTBE biodegradation was inhibited, an engineered approach to enhance in situ bioremediation could supply O2 at relatively low levels (e.g. 2-3 mg/L) to effectively stimulate MTBE biodegradation, which has significant practical advantages. The study shows that aerobic MTBE biodegradation can occur at environmentally significant rates in this aquifer, and that long-term microcosm experiments (100s days) may be necessary to correctly interpret contaminant biodegradation potential in aquifers to support site management decisions.

An examination of the physical properties, fate, ecotoxicity and potential environmental risks for a series of propylene glycol ethers.

PubMed

Staples, Charles A; Davis, John W

2002-10-01

Propylene glycol ethers (PGEs) are comprised of mono-, di- and tri-PGEs and several of their acetate esters. The nature of the range of applications that use PGEs suggests that there is a potential for both intentional and unintentional entry of the materials into the environment. Selected physical/chemical properties, fate characteristics, aquatic toxicity data and calculated environmental concentrations were used to assess potential risks from the manufacture, handling, use, and disposal of PGEs. In general, the PGEs are low to moderately volatile, have high aqueous solubilities, low octanol-water partition coefficients (Kow), and bioconcentration factor values of <10, which indicate they are unlikely to accumulate in aquatic food chains. Both abiotic and biological degradation processes reduce environmental concentrations of PGEs. In air, vapor-phase PGEs react with photo-chemically produced hydroxyl radicals and have half-lives ranging from 5.5 to 34.4 h. A variety of ready and inherent biodegradation test methods, as well as tests that simulate biodegradation in wastewater treatment plants, surface water and soil have been conducted on PGEs. Significant aerobic biodegradation was generally observed, with a range of biodegradation half-lives on the order of 5-25 d. Acute aquatic toxicity studies with PGEs resulted in LC50 values ranging from approximately >100 to >20,000 mg/l for freshwater fish, the pelagic invertebrate Daphnia magna, green algae Selenastrum capricornutum (now called Pseudokirchneriella capricornutum) and bacteria. Level 3 multi-media modeling (EQC model of Mackay) was used to simulate regional-scale concentrations of PGEs in air, soil, water, and sediment. Toxicity thresholds were then compared with regional-scale water, soil and sediment concentrations to determine hazard quotients. Based upon this analysis, concentrations of PGEs are unlikely to pose adverse risks to the environment.

Environmental Assessment, Repair of the Dam at Non-Potable Reservoir #1, United States Air Force Academy, Colorado

DTIC Science & Technology

2015-08-01

crimping alone is insufficient. Hydro-mulch shall be applied using a color dye and the manufacturer’s recommended rate of an organic tackifier. D...drainage areas where erosion is probable. All erosion control blanket shall be 100% biodegradable , net- free, wood fiber (excelsior) or coconut...Manufactured biodegradable stakes (6-inch minimum) or wooden stakes (8-inch minimum) shall be used to anchor any erosion materials; metal staples

Insights on the criteria of selection of vegetable and mineral dielectric fluids used in power transformers on the basis of their biodegradability and toxicity assessments.

PubMed

Módenes, Aparecido Nivaldo; Sanderson, Karina; Trigueros, Daniela Estelita Goes; Schuelter, Adilson Ricken; Espinoza-Quiñones, Fernando Rodolfo; Neves, Camila Vargas; Zanão Junior, Luiz Antônio; Kroumov, Alexander Dimitrov

2018-05-01

Leakage of transformer dielectric fluids is a concern because it may pose a risk of environmental contamination. In this study, the deleterious effects of vegetable and mineral dielectric fluids in water bodies were investigated using biodegradability and acute toxicity tests with Danio rerio and Artemia salina. Regarding biodegradability, all four tested vegetable oils (soy, canola, sunflower and crambe) were considered as easily biodegradable, presenting degradation rates significantly higher than the Lubrax-type mineral fluid. Acute toxicity tests were performed in two separate experiments without solution renewal. In the first experiment, the organisms were exposed in direct contact to different concentrations of vegetable (soy) and mineral (Lubrax) oils. Total soy-type vegetable oil has a higher toxic effect than Lubrax-type mineral oil. In the second experiment, the organisms were exposed to increasing percentages of the water-soluble fraction (WSF) of both types of tested oils. The LC 50 values for the water-soluble fraction of the Lubrax-type mineral oil were about 5 and 8% for the Danio rerio and Artemia salina bioindicators, respectively, whereas the vegetable oil did not present toxic effect, regardless of its WSF. These results have shown that a strict selection of dielectric fluids and monitoring the leakage from power transformers is a serious duty of environmental protection agencies. Copyright © 2018 Elsevier Ltd. All rights reserved.

Transformation of acesulfame in water under natural sunlight: joint effect of photolysis and biodegradation.

PubMed

Gan, Zhiwei; Sun, Hongwen; Wang, Ruonan; Hu, Hongwei; Zhang, Pengfei; Ren, Xinhao

2014-11-01

The transformation of acesulfame in water under environmentally relevant conditions, including direct and indirect photolysis, biodegradation, and hydrolysis, was systematically evaluated. Under natural sunlight, both direct and indirect photolysis of acesulfame were negligible in sterilized systems at neutral or alkaline pH, whereas direct photolysis occurred at pH of 4 with a rate constant of 0.0355 d(-1) in deionized water. No significant reduction in acesulfame contents was found in the dark controls or in the incubation experiments, indicating acesulfame was resistant to hydrolysis and biodegradation. In unsterilized systems, photolysis was substantially enhanced, implying that there was a joint effect of photolysis and biodegradation or that the sterilization process had the secondary effect of inactivating some photosensitizers. The near-surface summer half-life of acesulfame in the water from the Haihe River was 9 d. Specific experiments revealed the involvement of (1)O2/(3)DOM* in acesulfame photolysis, whereas OH exhibited only a slight contribution in the presence of DOM or bicarbonate. As indicated by the total organic carbon data, no significant mineralization occurred in both sterilized and unsterilized systems after acesulfame was irradiated under simulated sunlight for 7 d, suggesting the generation of persistent intermediates. Finally, major degradation intermediates were analyzed, and the degradation pathways of acesulfame under environmentally relevant conditions were proposed for the first time. Copyright © 2014 Elsevier Ltd. All rights reserved.

Biodegradability, toxicity and mutagenicity of detergents: Integrated experimental evaluations.

PubMed

Pedrazzani, Roberta; Ceretti, Elisabetta; Zerbini, Ilaria; Casale, Rosario; Gozio, Eleonora; Bertanza, Giorgio; Gelatti, Umberto; Donato, Francesco; Feretti, Donatella

2012-10-01

The widespread use of detergents has raised concern with regard to the environmental pollution caused by their active ingredients, which are biorefractory, toxic and persistent. Since detergents are complex mixtures of different substances, in which synergistic effects may occur, we aimed to assess the mutagenicity of different detergent formulations, taking into account aquatic toxicity and ready biodegradability. We performed a ready biodegradability test (OECD 301 F), Daphnia magna and Vibrio fischeri toxicity tests, and mutagenicity tests (Salmonella/microsome test, Allium cepa test and comet assay). Six detergent formulations were examined, 3 pre-manufacture and 3 commercially available. All detergents presented ready biodegradability. EC50 values varied for all products, according to the marker organism used, but were always higher than the more stringent value considered for aquatic toxicity assessment (V. fischeri 10-60 mg/L; D. magna 25-300 mg/L; A. cepa 250-2000 mg/L). None of the detergents caused mutations in bacteria. However, one commercial ecolabelled product induced an increase in micronucleus frequency in A. cepa root cells. All pre-manufacture detergents and one commercial one, which gave negative results in the Ames and A. cepa tests, induced DNA damage in human leukocytes. A more accurate evaluation of the environmental impact of complex mixtures such as detergents requires a battery of tests to describe degradation, as well as toxicological and mutagenic features. Copyright © 2012 Elsevier Inc. All rights reserved.

Characterizing the intrinsic bioremediation potential of 1,4-dioxane and trichloroethene using innovative environmental diagnostic tools.

PubMed

Chiang, Sheau-Yun Dora; Mora, Rebecca; Diguiseppi, William H; Davis, Greg; Sublette, Kerry; Gedalanga, Phillip; Mahendra, Shaily

2012-09-01

An intrinsic biodegradation study involving the design and implementation of innovative environmental diagnostic tools was conducted to evaluate whether monitored natural attenuation (MNA) could be considered as part of the remedial strategy to treat an aerobic aquifer contaminated with 1,4-dioxane and trichloroethene (TCE). In this study, advanced molecular biological and stable isotopic tools were applied to confirm in situ intrinsic biodegradation of 1,4-dioxane and TCE. Analyses of Bio-Trap® samplers and groundwater samples collected from monitoring wells verified the abundance of bacteria and enzymes capable of aerobically degrading TCE and 1,4-dioxane. Furthermore, phospholipid fatty acid analysis with stable isotope probes (PLFA-SIP) of the microbial community validated the ability for microbial degradation of TCE and 1,4-dioxane. Compound specific isotope analysis (CSIA) of groundwater samples for TCE resulted in δ(13)C values that indicated likely biodegradation of TCE in three of the four monitoring wells sampled. Results of the MNA evaluation showed that enzymes capable of aerobically degrading TCE and 1,4-dioxane were present, abundant, and active in the aquifer. Taken together, these results provide direct evidence of the occurrence of TCE and 1,4-dioxane biodegradation at the study site, supporting the selection of MNA as part of the final remedy at some point in the future.

Bacteria contribute to pesticide degradation in cryoconite holes in an Alpine glacier.

PubMed

Ferrario, Claudia; Pittino, Francesca; Tagliaferri, Ilario; Gandolfi, Isabella; Bestetti, Giuseppina; Azzoni, Roberto Sergio; Diolaiuti, Guglielmina; Franzetti, Andrea; Ambrosini, Roberto; Villa, Sara

2017-11-01

Organic contaminants deposited on glacier snow and ice are subject to partitioning and degradation processes that determine their environmental fate and, consequently, their accumulation in ice bodies. Among these processes, organic compound degradation by supraglacial bacteria has been investigated to a lesser extent than photo- and chemical degradation. We investigated biodegradation of the organophosphorus insecticide chlorpyrifos (CPF), a xenobiotic tracer that accumulates on glaciers after atmospheric medium- and long-range transport, by installing in situ microcosms on an Alpine glacier to simulate cryoconite hole systems. We found that biodegradation contributed to the removal of CPF from the glacier surface more than photo- and chemical degradation. The high concentration of CPF (2-3 μg g -1 w.w.) detected in cryoconite holes and the estimated half-life of this compound (35-69 days in glacier environment) indicated that biodegradation can significantly reduce CPF concentrations on glaciers and its runoff to downstream ecosystems. The metabolic versatility of cryoconite bacteria suggests that these habitats might contribute to the degradation of a wide class of pollutants. We therefore propose that cryoconite acts as a "biofilter" by accumulating both pollutants and biodegradative microbial communities. The contribution of cryoconite to the removal of organic pollutants should be included in models predicting the environmental fate of these compounds in cold areas. Copyright © 2017 Elsevier Ltd. All rights reserved.

Settlement behavior of municipal solid waste due to internal and external environmental factors in a lysimeter.

PubMed

Melo, Márcio C; Caribé, Rômulo M; Ribeiro, Libânia S; Sousa, Raul B A; Monteiro, Veruschka E D; de Paiva, William

2016-12-05

Long-term settlement magnitude is influenced by changes in external and internal factors that control the microbiological activity in the landfill waste body. To improve the understanding of settlement phenomena, it is instructive to study lysimeters filled with MSW. This paper aims to understand the settlement behavior of MSW by correlating internal and external factors that influence waste biodegradation in a lysimeter. Thus, a lysimeter was built, instrumented and filled with MSW from the city of Campina Grande, the state of Paraíba, Brazil. Physicochemical analysis of the waste (from three levels of depth of the lysimeter) was carried out along with MSW settlement measurements. Statistical tools such as descriptive analysis and principal component analysis (PCA) were also performed. The settlement/compression, coefficient of variation and PCA results indicated the most intense rate of biodegradation in the top layer. The PCA results of intermediate and bottom levels presented fewer physicochemical and meteorological variables correlated with compression data in contrast with the top layer. It is possible to conclude that environmental conditions may influence internal indicators of MSW biodegradation, such as the settlement.

Cultivation and Characterization of Oil-Degrading Microbes and the Environmental Controls on Hydrocarbon Biodegradation Patterns

NASA Astrophysics Data System (ADS)

Redmond, M. C.

2016-02-01

The Deepwater Horizon oil spill highlighted the ability of microbes to degrade hydrocarbons in both cold, deep water and at the warm sea surface. However, the temperature and differing hydrocarbons in the deep ocean and sea surface led to different microbial communities and biodegradation patterns. In order to develop a better understanding of the factors that control microbial community composition and biodegradation patterns, we conducted laboratory microcosm studies with seawater samples from coastal South Carolina and hydrocarbon seeps in the Gulf of Mexico, incubated with different hydrocarbons, at different temperatures, and in static or shaking incubation conditions. We analyzed microbial community composition after three weeks and used successive transfers on liquid and then solid media to isolate cultures. More rapid growth was observed at 28 degrees than 4 degrees, with hexadecane compared to benzene, cyclohexane, or crude oil, and in shaking incubations compared to static. However, we were able to successfully culture microbes under all conditions. Physiological and genetic characterization of isolated strains is ongoing, and will be combined with assessment of hydrocarbon substrate preferences and kinetics under different environmental conditions.

Investigation of the combustion kinetics and polycyclic aromatic hydrocarbon emissions from polycaprolactone combustion.

PubMed

Chien, Y C; Yang, S H

2013-01-01

Polycaprolactone (PCL) is one of the most attractive biodegradable plastics that has been widely used in medicine and agriculture fields. Because of the large increase in biodegradable plastics usage, the production of waste biodegradable plastics will be increasing dramatically, producing a growing environmental problem. Generally, waste PCL is collected along with municipal solid wastes and then incinerated. This study investigates the combustion kinetics and emission factors of 16 US Environmental Protection Agency (EPA) priority polycyclic aromatic hydrocarbons (PAHs) in the PCL combustion. Experimentally, two reactions are involved in the PCL combustion process, possibly resulting in the emission of carbon dioxide, propanal, protonated caprolactone and very small amounts of PAH produced by incomplete combustion. The intermediate products may continuously be oxidized to form CO2. The emission factors for 16 US EPA priority PAHs are n.d. -2.95 microg/g, which are much lower than those of poly lactic acid and other plastics combustion. The conversion of PCL is 100%. Results from this work suggest that combustion is a good choice for the waste PCL disposal.

Fringe-controlled biodegradation under dynamic conditions: quasi 2-D flow-through experiments and reactive-transport modeling.

PubMed

Eckert, Dominik; Kürzinger, Petra; Bauer, Robert; Griebler, Christian; Cirpka, Olaf A

2015-01-01

Biodegradation in contaminated aquifers has been shown to be most pronounced at the fringe of contaminant plumes, where mixing of contaminated water and ambient groundwater, containing dissolved electron acceptors, stimulates microbial activity. While physical mixing of contaminant and electron acceptor by transverse dispersion has been shown to be the major bottleneck for biodegradation in steady-state plumes, so far little is known on the effect of flow and transport dynamics (caused, e.g., by a seasonally fluctuating groundwater table) on biodegradation in these systems. Towards this end we performed experiments in quasi-two-dimensional flow-through microcosms on aerobic toluene degradation by Pseudomonas putida F1. Plume dynamics were simulated by vertical alteration of the toluene plume position and experimental results were analyzed by reactive-transport modeling. We found that, even after disappearance of the toluene plume for two weeks, the majority of microorganisms stayed attached to the sediment and regained their full biodegradation potential within two days after reappearance of the toluene plume. Our results underline that besides microbial growth, also maintenance and dormancy are important processes that affect biodegradation performance under transient environmental conditions and therefore deserve increased consideration in future reactive-transport modeling. Copyright © 2014 Elsevier B.V. All rights reserved.

Resolving biodegradation patterns of persistent saturated hydrocarbons in weathered oil samples from the Deepwater Horizon disaster.

PubMed

Gros, Jonas; Reddy, Christopher M; Aeppli, Christoph; Nelson, Robert K; Carmichael, Catherine A; Arey, J Samuel

2014-01-01

Biodegradation plays a major role in the natural attenuation of oil spills. However, limited information is available about biodegradation of different saturated hydrocarbon classes in surface environments, despite that oils are composed mostly of saturates, due to the limited ability of conventional gas chromatography (GC) to resolve this compound group. We studied eight weathered oil samples collected from four Gulf of Mexico beaches 12-19 months after the Deepwater Horizon disaster. Using comprehensive two-dimensional gas chromatography (GC × GC), we successfully separated, identified, and quantified several distinct saturates classes in these samples. We find that saturated hydrocarbons eluting after n-C22 dominate the GC-amenable fraction of these weathered samples. This compound group represented 8-10%, or 38-68 thousand metric tons, of the oil originally released from Macondo well. Saturates in the n-C22 to n-C29 elution range were found to be partly biodegraded, but to different relative extents, with ease of biodegradation decreasing in the following order: n-alkanes > methylalkanes and alkylcyclopentanes+alkylcyclohexanes > cyclic and acyclic isoprenoids. We developed a new quantitative index designed to characterize biodegradation of >n-C22 saturates. These results shed new light onto the environmental fate of these persistent, hydrophobic, and mostly overlooked compounds in the unresolved complex mixtures (UCM) of weathered oils.

The Potential of Lignolytic Trichoderma Isolates in LDPE (Low Density Polyethylene) Plastic Biodegradation

NASA Astrophysics Data System (ADS)

Hikmah, M.; Setyaningsih, R.; Pangastuti, A.

2018-03-01

Plastic is experiencing buildup in the environment. Biodegradation process can be used as an alternative for LDPE plastic degradation because the process is environmentally friendly. Some fungi of the genus Trichoderma are known to have a role in plastic biodegradation. This study aims to find out how the potential of that lignolytic Trichoderma spp. isolates in LDPE biodegradation. Five isolates were screened by growing on MSMB (mineral salt medium broth) emulsified LDPE powder, with 35 days incubation at 30°C and shaking at 80 rpm. TL1, TL4, and TL5 are the three most potential isolates, indicated by the growth marked by increasing colony size on screening media. They were then tested for biodegradability by growing the isolates in MSMA (mineral salt medium agar) which then inoculated by 4 sheets of sterile LDPE 1x3 cm2 above the colony surface, incubated for 5, 15, 25 and 35 days. The degredability assessment is done by measuring the weight loss of LDPE sheets after biodegradation treatment. The obtained degradability percentage of TL1, TL4, and TL5 are 4.87%, 7.12%, and 7,51% respectively. The visual micrograph of LDPE film by SEM showed the appearance of damage and unevenness on the surface of the post-degradation film.

ENVIRONMENTAL TRANSPORT, BIODEGRADATION, AND BIOACCUMULATION OF QUANTUM DOTS AND OXIDE NANOPARTICLES

EPA Science Inventory

The proposed work will provide, for the first time, data on the environmental stability and mobility of QD and MO as a function of their formulation. The unique application of capillary electrophoresis in measuring binding constants of nanoparticles with NOM could provide a pr...

Presidential Green Chemistry Challenge: 2005 Small Business Award

EPA Pesticide Factsheets

Presidential Green Chemistry Challenge 2005 award winner, Metabolix, used biotechnology to develop microorganisms that produce polyhydroxyalkanoates: natural, biodegradable plastics with a range of environmental benefits.

Management of soybean oil refinery wastes through recycling them for producing biosurfactant using Pseudomonas aeruginosa MR01.

PubMed

Partovi, Maryam; Lotfabad, Tayebe Bagheri; Roostaazad, Reza; Bahmaei, Manochehr; Tayyebi, Shokoufe

2013-06-01

Biosurfactant production through a fermentation process involving the biodegradation of soybean oil refining wastes was studied. Pseudomonas aeruginosa MR01 was able to produce extracellular biosurfactant when it was cultured in three soybean oil refinement wastes; acid oil, deodorizer distillate and soapstock, at different carbon to nitrogen ratios. Subsequent fermentation kinetics in the three types of waste culture were also investigated and compared with kinetic behavior in soybean oil medium. Biodegradation of wastes, biosurfactant production, biomass growth, nitrate consumption and the number of colony forming units were detected in four proposed media, at specified time intervals. Unexpectedly, wastes could stimulate the biodegradation activity of MR01 bacterial cells and thus biosurfactant synthesis beyond that of the refined soybean oil. This is evident from higher yields of biodegradation and production, as revealed in the waste cultures (Ydeg|(Soybean oil) = 53.9 % < Ydeg|(wastes) and YP/S|(wastes) > YP/S|(Soybean oil) = 0.31 g g(-1), respectively). Although production yields were approximately the same in the three waste cultures (YP/S|(wastes) =/~ 0.5 g g(-1)), microbial activity resulted in higher yields of biodegradation (96.5 ± 1.13 %), maximum specific growth rate (μ max = 0.26 ± 0.02 h(-1)), and biosurfactant purity (89.6 %) with a productivity of 14.55 ± 1.10 g l(-1), during the bioconversion of soapstock into biosurfactant. Consequently, applying soybean oil soapstock as a substrate for the production of biosurfactant with commercial value has the potential to provide a combination of economical production with environmental protection through the biosynthesis of an environmentally friendly (green) compound and reduction of waste load entering the environment. Moreover, this work inferred spectrophotometry as an easy method to detect rhamnolipids in the biosurfactant products.

Evaluation of biodegradable plastics for rubber seedling applications

NASA Astrophysics Data System (ADS)

Mansor, Mohd Khairulniza; Dayang Habibah A. I., H.; Kamal, Mazlina Mustafa

2015-08-01

The main negative consequence of conventional plastics in agriculture is related to handling the wastes plasticand the associated environmental impact. Hence, a study of different types of potentially biodegradable plastics used for nursery applications have been evaluated on its mechanical,water absorption propertiesand Fourier transform infra-red (FTIR) spectroscopy. Supplied samples from different companies were designated as SF, CF and CO. Most of the polybags exhibited mechanical properties quite similar to the conventional plastics (polybag LDPE). CO polybag which is based on PVA however had extensively higher tensile strength and water absorption properties. FTIR study revealed a characteristics absorbance of conventional plastic, SF, CF and CO biodegradable polybag are associated with polyethylene, poly(butylene adipate-co-terephthalate) (PBAT), polyethylene and polyvinyl alcohol (PVA) structures respectively.

Characteristics and environmental fate of the anionic surfactant sodium lauryl ether sulphate (SLES) used as the main component in foaming agents for mechanized tunnelling.

PubMed

Barra Caracciolo, Anna; Cardoni, Martina; Pescatore, Tanita; Patrolecco, Luisa

2017-07-01

The anionic surfactant sodium lauryl ether sulphate (SLES) is the main component of most commercial products used for soil conditioning in the excavation industry, in particular as lubricants for mechanized tunnelling. Its use during the excavation processes can result in either the subsequent possible re-use of the huge amount of soil debris as by-products (e.g. land covering) or its discharge as waste. Currently, there are neither SLES soil threshold limits in European legislation, nor comprehensive studies on the environmental risk for soil ecosystems in these exposure scenarios. In this context, the present paper reviews the available data on the intrinsic characteristics of persistence and the ecotoxicological effects of the anionic surfactant SLES. Although SLES is generally reported to be biodegradable in standard tests, with degradation rates between 7 h and 30 days, depending on the initial conditions, data on its biodegradation in environmental studies are quite scarce. Consequently, assessing SLES biodegradation rates in field conditions is crucial for evaluating if in residual concentrations (typically in the range 40-500 mg/kg in excavated soils) it can or not be a potential hazard for terrestrial and water organisms. Laboratory ecotoxicological tests pointed out detrimental effects of SLES for aquatic organisms, while data on the terrestrial species are rather poor so far and further studies at the expected environmental concentrations are necessary. Finally, the review reports the main analytical methods available for detecting anionic surfactants in solid matrices and the future research needed to improve knowledge on the possible environmental risks posed by the use of SLES in foaming agents for mechanized tunnelling. Copyright © 2017 Elsevier Ltd. All rights reserved.

Microbial Factors Rather Than Bioavailability Limit the Rate and Extent of PAH Biodegradation in Aged Crude Oil Contaminated Model Soils

DOE Office of Scientific and Technical Information (OSTI.GOV)

Huesemann, Michael H.; Hausmann, Tom S.; Fortman, Timothy J.

The rate and extent of PAH biodegradation in a set of aged, crude oil contaminated model soils were measured in 90-week slurry bioremediation experiments. Soil properties such as organic matter content, mineral type, particle diameter, surface area, and porosity did not significantly influence the PAH biodegradation kinetics among the ten different model soils. A comparison of aged and freshly spiked soils indicates that aging affects the biodegradation rates and extents only for higher molecular weight PAHs while the effects of aging are insignificant for 3-ring PAHs and total PAHs. In all model soils with the exception of kaolinite clay, themore » rate of abiotic desorption was faster than the rate of biodegradation during the initial phase of bioremediation treatment indicating that PAH biodegradation was limited by microbial factors. Similarly, any of the higher molecular weight PAHs that were still present after 90 weeks of treatment were released rapidly during abiotic desorption tests which demonstrates that bioavailability limitations were not responsible for the recalcitrance of these hydrocarbons. Indeed, an analysis of microbial counts indicates that a severe reduction in hydrocarbon degrader populations may be responsible for the observed incomplete PAH biodegradation. It can therefore be concluded that the recalcitrance of PAHs during bioremediation is not necessarily due to bioavailability limitations and that these residual contaminants might, therefore, pose a greater risk to environmental receptors than previously thought.« less

Naphthalene biodegradation in temperate and arctic marine microcosms.

PubMed

Bagi, Andrea; Pampanin, Daniela M; Lanzén, Anders; Bilstad, Torleiv; Kommedal, Roald

2014-02-01

Naphthalene, the smallest polycyclic aromatic hydrocarbon (PAH), is found in abundance in crude oil, its major source in marine environments. PAH removal occurs via biodegradation, a key process determining their fate in the sea. Adequate estimation of PAH biodegradation rates is essential for environmental risk assessment and response planning using numerical models such as the oil spill contingency and response (OSCAR) model. Using naphthalene as a model compound, biodegradation rate, temperature response and bacterial community composition of seawaters from two climatically different areas (North Sea and Arctic Ocean) were studied and compared. Naphthalene degradation was followed by measuring oxygen consumption in closed bottles using the OxiTop(®) system. Microbial communities of untreated and naphthalene exposed samples were analysed by polymerase chain reaction denaturing gradient gel electrophoresis (PCR-DGGE) and pyrosequencing. Three times higher naphthalene degradation rate coefficients were observed in arctic seawater samples compared to temperate, at all incubation temperatures. Rate coefficients at in situ temperatures were however, similar (0.048 day(-1) for temperate and 0.068 day(-1) for arctic). Naphthalene biodegradation rates decreased with similar Q10 ratios (3.3 and 3.5) in both seawaters. Using the temperature compensation method implemented in the OSCAR model, Q10 = 2, biodegradation in arctic seawater was underestimated when calculated from the measured temperate k1 value, showing that temperature difference alone could not predict biodegradation rates adequately. Temperate and arctic untreated seawater communities were different as revealed by pyrosequencing. Geographic origin of seawater affected the community composition of exposed samples.

Improving rice production sustainability by reducing water demand and greenhouse gas emissions with biodegradable films

NASA Astrophysics Data System (ADS)

Yao, Zhisheng; Zheng, Xunhua; Liu, Chunyan; Lin, Shan; Zuo, Qiang; Butterbach-Bahl, Klaus

2017-01-01

In China, rice production is facing unprecedented challenges, including the increasing demand, looming water crisis and on-going climate change. Thus, producing more rice at lower environmental cost is required for future development, i.e., the use of less water and the production of fewer greenhouse gas (GHG) per unit of rice. Ground cover rice production systems (GCRPSs) could potentially address these concerns, although no studies have systematically and simultaneously evaluated the benefits of GCRPS regarding yields and considering water use and GHG emissions. This study reports the results of a 2-year study comparing conventional paddy and various GCRPS practices. Relative to conventional paddy, GCRPSs had greater rice yields and nitrogen use efficiencies (8.5% and 70%, respectively), required less irrigation (-64%) and resulted in less total CH4 and N2O emissions (-54%). On average, annual emission factors of N2O were 1.67% and 2.00% for conventional paddy and GCRPS, respectively. A cost-benefit analysis considering yields, GHG emissions, water demand and labor and mulching costs indicated GCRPSs are an environmentally and economically profitable technology. Furthermore, substituting the polyethylene film with a biodegradable film resulted in comparable benefits of yield and climate. Overall, GCRPSs, particularly with biodegradable films, provide a promising solution for farmers to secure or even increase yields while reducing the environmental footprint.

Nitroaromatic Compounds, from Synthesis to Biodegradation

PubMed Central

Ju, Kou-San; Parales, Rebecca E.

2010-01-01

Summary: Nitroaromatic compounds are relatively rare in nature and have been introduced into the environment mainly by human activities. This important class of industrial chemicals is widely used in the synthesis of many diverse products, including dyes, polymers, pesticides, and explosives. Unfortunately, their extensive use has led to environmental contamination of soil and groundwater. The nitro group, which provides chemical and functional diversity in these molecules, also contributes to the recalcitrance of these compounds to biodegradation. The electron-withdrawing nature of the nitro group, in concert with the stability of the benzene ring, makes nitroaromatic compounds resistant to oxidative degradation. Recalcitrance is further compounded by their acute toxicity, mutagenicity, and easy reduction into carcinogenic aromatic amines. Nitroaromatic compounds are hazardous to human health and are registered on the U.S. Environmental Protection Agency's list of priority pollutants for environmental remediation. Although the majority of these compounds are synthetic in nature, microorganisms in contaminated environments have rapidly adapted to their presence by evolving new biodegradation pathways that take advantage of them as sources of carbon, nitrogen, and energy. This review provides an overview of the synthesis of both man-made and biogenic nitroaromatic compounds, the bacteria that have been identified to grow on and completely mineralize nitroaromatic compounds, and the pathways that are present in these strains. The possible evolutionary origins of the newly evolved pathways are also discussed. PMID:20508249

Numerical study on injection parameters optimization of thin wall and biodegradable polymers parts

NASA Astrophysics Data System (ADS)

Santos, C.; Mendes, A.; Carreira, P.; Mateus, A.; Malça, C.

2017-07-01

Nowadays, the molds industry searches new markets, with diversified and added value products. The concept associated to the production of thin walled and biodegradable parts mostly manufactured by injection process has assumed a relevant importance due to environmental and economic factors. The growth of a global consciousness about the harmful effects of the conventional polymers in our life quality associated with the legislation imposed, become key factors for the choice of a particular product by the consumer. The target of this work is to provide an integrated solution for the injection of parts with thin walls and manufactured using biodegradable materials. This integrated solution includes the design and manufacture processes of the mold as well as to find the optimum values for the injection parameters in order to become the process effective and competitive. For this, the Moldflow software was used. It was demonstrated that this computational tool provides an effective responsiveness and it can constitute an important tool in supporting the injection molding of thin-walled and biodegradable parts.

The nonylphenol biodegradation study by estuary sediment-derived fungus Penicillium simplicissimum.

PubMed

Zhang, Yan; Liu, Ying; Dong, Han; Li, Xianguo; Zhang, Dahai

2016-08-01

Nonylphenols (NPs) are persistent organic pollutants (POPs) with estrogenic properties that can perform endocrine-disrupting activities. By using high-concentration NP as environmental selection pressure, one NP biodegradation strain named NPF-4 was isolated and purified from estuary sediment of the Moshui River. It was identified as Penicillium simplicissimum (PS1) by appearance and 18S rDNA analysis. In different culture situations, the strain mass growth and biodegradation ability were evaluated. Within 4-n-nonylphenol (4-n-NP) initial concentration of 20 mg L(-1), it could be degraded 53.76, 90.08, and 100.00 % at 3, 7, and 14 days, respectively. In feeding experiments, it showed that NPF-4 could use 4-n-NP as a sole carbon source. Based on seven products/intermediates detected with GC and LC-MS, a novel biopathway for 4-n-NP biodegradation was proposed, in which sequential hydroxylation, oxidation, and decarboxylation at terminal β-C atom may occur for 4-n-NP detoxification, even complete mineralization in the end.

Aquatic toxicity and biodegradability of a surfactant produced by Bacillus subtilis ICA56.

PubMed

De Oliveira, Darlane W F; Cara, Alejandro B; Lechuga-Villena, Manuela; García-Román, Miguel; Melo, Vania M M; Gonçalves, Luciana R B; Vaz, Deisi A

2017-01-28

In this work, the environmental compatibility of a biosurfactant produced by a Bacillus subtilis strain isolated from the soil of a Brazilian mangrove was investigated. The biosurfactant, identified as surfactin, is able to reduce surface tension (ST) to 31.5 ± 0.1 mN m -1 and exhibits a lowcritical micelle concentration (CMC) value (0.015 ± 0.003 g L -1 ). The highest crude biosurfactant concentration (224.3 ± 1.9 mg L -1 ) was reached at 72 h of fermentation. Acute toxicity tests, carried out with Daphnia magna, Vibrio fischeri and Selenastrum capricornutum indicated that the toxicity of the biosurfactant is lower than that of its chemically derived counterparts. The results of the biodegradability tests demonstrated that the crude surfactin extract was degraded by both Pseudomonas putida and a mixed population from a sewage-treatment plant, in both cases the biodegradation efficiency being dependent on the initial concentration of the biosurfactant. Finally, as the biodegradation percentages obtained fall within the acceptance limits established by the Organization for Economic Co-operation and Development (Guidelines for Testing of Chemicals, OECD 301E), crude surfactin can be classified as a "readily" biodegradable compound.

The biochemistry and molecular biology of xenobiotic polymer degradation by microorganisms.

PubMed

Kawai, Fusako

2010-01-01

Research on microbial degradation of xenobiotic polymers has been underway for more than 40 years. It has exploited a new field not only in applied microbiology but also in environmental microbiology, and has greatly contributed to polymer science by initiating the design of biodegradable polymers. Owing to the development of analytical tools and technology, molecular biological and biochemical advances have made it possible to prospect for degrading microorganisms in the environment and to determine the mechanisms involved in biodegradation when xenobiotic polymers are introduced into the environment and are exposed to microbial attack. In this review, the molecular biological and biochemical aspects of the microbial degradation of xenobiotic polymers are summarized, and possible applications of potent microorganisms, enzymes, and genes in environmental biotechnology are suggested.

THz+X Seedling Report

DTIC Science & Technology

2005-11-23

lamblia Entamoeba histolytica Toxoplasma Microsporidia Additional viral encephalitides West Nile Virus LaCrosse California encephalitis VEE...Is Catalyzed by Salicylate 1- Monooxygenase from Pseudomonas sp . Strain ATCC 29352; Applied and Environmental Microbiology, July 2004, p. 4040-4047...the Mechanism of RDX Biodegradation by Rhodococcus - 31 - sp . Strain DN22; Applied and Environmental Microbiology, March 2003, p. 1347-1351

Biodegradation of PVP-CMC hydrogel film: a useful food packaging material.

PubMed

Roy, Niladri; Saha, Nabanita; Kitano, Takeshi; Saha, Petr

2012-06-20

Hydrogels can offer new opportunities for the design of efficient packaging materials with desirable properties (i.e. durability, biodegradability and mechanical strength). It is a promising and emerging concept, as most of the biopolymer based hydrogels are supposed to be biodegradable, they can be considered as alternative eco-friendly packaging materials. This article reports about synthetic (polyvinylpyrrolidone (PVP)) and biopolymer (carboxymethyl cellulose (CMC)) based a novel hydrogel film and its nature of biodegradability under controlled environmental condition. The dry hydrogel films were prepared by solution casting method and designated as 'PVP-CMC hydrogel films'. The hydrogel film containing PVP and CMC in a ratio of 20:80 shows best mechanical properties among all the test samples (i.e. 10:90, 20:80, 50:50, 80:20 and 90:10). Thus, PVP-CMC hydrogel film of 20:80 was considered as a useful food packaging material and further experiments were carried out with this particular hydrogel film. Biodegradation of the PVP-CMC hydrogel films were studied in liquid state (Czapec-Dox liquid medium+soil extracts) until 8 weeks. Variation in mechanical, viscoelastic properties and weight loss of the hydrogel films with time provide the direct evidence of biodegradation of the hydrogels. About 38% weight loss was observed within 8 weeks. FTIR spectra of the hydrogel films (before and after biodegradation) show shifts of the peaks and also change in the peak intensities, which refer to the physico-chemical change in the hydrogel structure and SEM views of the hydrogels show how internal structure of the PVP-CMC film changes in the course of biodegradation. Copyright © 2012 Elsevier Ltd. All rights reserved.

Controlling the biodegradability of poly(butylene succinate-co-butylene adipate) (PBSA) by solvents used in the dried-gel process

NASA Astrophysics Data System (ADS)

Yamazaki, Hana; Kamitabira, Saya; Maeda, Tomoki; Hotta, Atsushi

Considering an environmentally friendly material, poly(butylene succinate-co-butylene adipate)(PBSA) is one of the attractive biodegradable plastics that can be eventually degraded into H2O and CO2 by neighboring water molecules and microorganisms after the disposal. In order to expand the application of PBSA, the precise control of the biodegradability of PBSA is necessary. In this study, the dried-gel process was introduced to control the biodegradability of PBSA. The dried PBSA gels were prepared by using three different solvents (toluene, cyclohexanone, and o-dichlorobenzene). The scanning electron microscopy (SEM) micrographs revealed that the PBSA prepared by toluene had smaller spherocrystals than the other PBSA dried-gels prepared by cyclohexanone or o-dichlorobenzene. The biodegradability testing by immersing the three types of PBSA in NaOH aq. showed that the percentage of the weight loss of the PBSA produced by toluene was the highest. The results indicated that the microstructures of PBSA could be controlled by changing solvents during the gel preparations, and that the biodegradability of PBSA could therefore be efficiently modified by changing solvents. This work was supported by a Grant-in-Aid for Scientific Research (A) (No. 15H02298 to A.H.) and a Grant-in-Aid for Research Activity Start-up (No.15H06586 to T.M.) from JSPS: KAKENHI\\x9D.

Localized Enzymatic Degradation of Polymers: Physics and Scaling Laws

NASA Astrophysics Data System (ADS)

Lalitha Sridhar, Shankar; Vernerey, Franck

2018-03-01

Biodegradable polymers are naturally abundant in living matter and have led to great advances in controlling environmental pollution due to synthetic polymer products, harnessing renewable energy from biofuels, and in the field of biomedicine. One of the most prevalent mechanisms of biodegradation involves enzyme-catalyzed depolymerization by biological agents. Despite numerous studies dedicated to understanding polymer biodegradation in different environments, a simple model that predicts the macroscopic behavior (mass and structural loss) in terms of microphysical processes (enzyme transport and reaction) is lacking. An interesting phenomenon occurs when an enzyme source (released by a biological agent) attacks a tight polymer mesh that restricts free diffusion. A fuzzy interface separating the intact and fully degraded polymer propagates away from the source and into the polymer as the enzymes diffuse and react in time. Understanding the characteristics of this interface will provide crucial insight into the biodegradation process and potential ways to precisely control it. In this work, we present a centrosymmetric model of biodegradation by characterizing the moving fuzzy interface in terms of its speed and width. The model predicts that the characteristics of this interface are governed by two time scales, namely the polymer degradation and enzyme transport times, which in turn depend on four main polymer and enzyme properties. A key finding of this work is simple scaling laws that can be used to guide biodegradation of polymers in different applications.

Biodegradation testing of chemicals with high Henry's constants - Separating mass and effective concentration reveals higher rate constants.

PubMed

Birch, Heidi; Andersen, Henrik R; Comber, Mike; Mayer, Philipp

2017-05-01

During simulation-type biodegradation tests, volatile chemicals will continuously partition between water phase and headspace. This study addressed how (1) this partitioning affects test results and (2) can be accounted for by combining equilibrium partition and dynamic biodegradation models. An aqueous mixture of 9 (semi)volatile chemicals was first generated using passive dosing and then diluted with environmental surface water producing concentrations in the ng/L to μg/L range. After incubation for 2 h to 4 weeks, automated Headspace Solid Phase Microextraction (HS-SPME) was applied directly on the test systems to measure substrate depletion by biodegradation relatively to abiotic controls. HS-SPME was also applied to determine air to water partitioning ratios. Biodegradation rate constants relating to the chemical in the water phase, k water , were generally a factor 1 to 11 times higher than biodegradation rate constants relating to the total mass of chemical in the test system, k system , with one exceptional factor of 72 times for a long chain alkane. True water phase degradation rate constants were found (i) more appropriate for risk assessment than test system rate constants, (ii) to facilitate extrapolation to other air-water systems and (iii) to be better defined input parameters for aquatic exposure and fate models. Copyright © 2017 Elsevier Ltd. All rights reserved.

Progresses in Polystyrene Biodegradation and Prospects for Solutions to Plastic Waste Pollution

NASA Astrophysics Data System (ADS)

Yang, S. S.; Brandon, A. M.; Xing, D. F.; Yang, J.; Pang, J. W.; Criddle, C. S.; Ren, N. Q.; Wu, W. M.

2018-05-01

Petroleum-based plastic pollution has been a global environmental concern for decades. The obvious contrast between the remarkable durability of the plastics and their short service time leads to the increasing accumulation of plastic wastes in the environment. A cost-effective, sustainable strategy to solve the problem should focus on source control and clean up. Polystyrene (PS) wastes, a recalcitrant plastic polymer, are among the wide spread man-made plastic pollutants. Destruction of PS wastes can be achieved using various abiotic methods such as incineration but such methods release potential air pollution and generation of hazardous by-products. Biodegradation and bioremediation has been proposed for years. Since the 1970’s, the microbial biodegradation of plastics, including PS, has been evaluated with mixed and isolated cultures from different sources such as activated sludge, trash, soil, and manure. To date, PS biodegradation by these microbial cultures is still quite slow. Recently, the larvae of yellow mealworms (Tenebrio molitor Linnaeus) have demonstrated promising PS biodegradation performance. Mealworms have demonstrated the ability to chew and ingest PS foam as food and are capable of degrading and mineralizing PS into CO2 via microbe-dependent activities within the gut in less than the 12-15 hrs gut retention time. These research results have revealed a potential for microbial biodegradation and bioremediation of plastic pollutants.

Evaluation of ethyl tert-butyl ether biodegradation in a contaminated aquifer by compound-specific isotope analysis and in situ microcosms.

PubMed

Bombach, Petra; Nägele, Norbert; Rosell, Mònica; Richnow, Hans H; Fischer, Anko

2015-04-09

Ethyl tert-butyl ether (ETBE) is an upcoming groundwater pollutant in Europe whose environmental fate has been less investigated, thus far. In the present study, we investigated the in situ biodegradation of ETBE in a fuel-contaminated aquifer using compound-specific stable isotope analysis (CSIA), and in situ microcosms in combination with total lipid fatty acid (TLFA)-stable isotope probing (SIP). In a first field investigation, CSIA revealed insignificant carbon isotope fractionation, but low hydrogen isotope fractionation of up to +14‰ along the prevailing anoxic ETBE plume suggesting biodegradation of ETBE. Ten months later, oxygen injection was conducted to enhance the biodegradation of petroleum hydrocarbons (PH) at the field site. Within the framework of this remediation measure, in situ microcosms loaded with [(13)C6]-ETBE (BACTRAP(®)s) were exposed for 119 days in selected groundwater wells to assess the biodegradation of ETBE by TLFA-SIP under the following conditions: (i) ETBE as main contaminant; (ii) ETBE as main contaminant subjected to oxygen injection; (iii) ETBE plus other PH; (iv) ETBE plus other PH subjected to oxygen injection. Under all conditions investigated, significant (13)C-incorporation into microbial total lipid fatty acids extracted from the in situ microcosms was found, providing clear evidence of ETBE biodegradation. Copyright © 2014 Elsevier B.V. All rights reserved.

Biodegradation of Perchlorate in Laboratory Reactors Under Different Environmental Conditions

DTIC Science & Technology

2010-07-01

California Office of Environmental Health Hazard Assessment (OEHHA) 2004). Massachusetts has proposed a regulatory standard of 2 µg/L (Massachusetts...perchlorate has been detected in some animal feed crops, dairy, and meat. Alfalfa, a beef cattle and dairy cow feed, tested at 109–555 µg/kg for samples...transported to the Engineer Research and Development Center (ERDC), Environmental Laboratory, Hazardous Waste Research Center, Vicksburg, MS. The

Physical performance of biodegradable films intended for antimicrobial food packaging.

PubMed

Marcos, Begonya; Aymerich, Teresa; Monfort, Josep M; Garriga, Margarita

2010-10-01

Antimicrobial films were prepared by including enterocins to alginate, polyvinyl alcohol (PVOH), and zein films. The physical performance of the films was assessed by measuring color, microstructure (SEM), water vapor permeability (WVP), and tensile properties. All studied biopolymers showed poor WVP and limited tensile properties. PVOH showed the best performance exhibiting the lowest WVP values, higher tensile properties, and flexibility among studied biopolymers. SEM of antimicrobial films showed increased presence of voids and pores as a consequence of enterocin addition. However, changes in microstructure did not disturb WVP of films. Moreover, enterocin-containing films showed slight improvement compared to control films. Addition of enterocins to PVOH films had a plasticizing effect, by reducing its tensile strength and increasing the strain at break. The presence of enterocins had an important effect on tensile properties of zein films by significantly reducing its brittleness. Addition of enterocins, thus, proved not to disturb the physical performance of studied biopolymers. Development of new antimicrobial biodegradable packaging materials may contribute to improving food safety while reducing environmental impact derived from packaging waste. Practical Application: Development of new antimicrobial biodegradable packaging materials may contribute to improving food safety while reducing environmental impact derived from packaging waste.

Spills of Hydraulic Fracturing Chemicals on Agricultural Topsoil: Biodegradation, Sorption, and Co-contaminant Interactions.

PubMed

McLaughlin, Molly C; Borch, Thomas; Blotevogel, Jens

2016-06-07

Hydraulic fracturing frequently occurs on agricultural land. Yet the extent of sorption, transformation, and interactions among the numerous organic frac fluid and oil and gas wastewater constituents upon environmental release is hardly known. Thus, this study aims to advance our current understanding of processes that control the environmental fate and toxicity of commonly used hydraulic fracturing chemicals. Poly(ethylene glycol) surfactants were completely biodegraded in agricultural topsoil within 42-71 days, but their transformation was impeded in the presence of the biocide glutaraldehyde and was completely inhibited by salt at concentrations typical for oil and gas wastewater. At the same time, aqueous glutaraldehyde concentrations decreased due to sorption to soil and were completely biodegraded within 33-57 days. While no aqueous removal of polyacrylamide friction reducer was observed over a period of 6 months, it cross-linked with glutaraldehyde, further lowering the biocide's aqueous concentration. These findings highlight the necessity to consider co-contaminant effects when we evaluate the risk of frac fluid additives and oil and gas wastewater constituents in agricultural soils in order to fully understand their human health impacts, likelihood for crop uptake, and potential for groundwater contamination.

Model ecosystem evaluation of the environmental impacts of the veterinary drugs phenothiazine, sulfamethazine, clopidol, and diethylstilbestrol.

PubMed Central

Coats, J R; Metcalf, R L; Lu, P Y; Brown, D D; Williams, J F; Hansen, L G

1976-01-01

Four veterinary drugs of dissimilar chemical structures were evaluated for environmental stability and penchant for bioaccumulation. The techniques used were (1) a model aquatic ecosystem (3 days) and (2) a model feedlot ecosystem (33 days) in which the drugs were introduced via the excreta of chicks or mice. The model feedlot ecosystem was supported by metabolism cage studies to determine the amount and the form of the drug excreted by the chicks or mice. Considerable quantities of all the drugs were excreted intact or as environmentally short-lived conjugates. Diethylstilbestrol (DES) and Clopidol were the most persistent molecules, but only DES bioaccumulated to any appreciable degree. Phenothiazine was very biodegradable; sulfamethazine was relatively biodegradable and only accumulated in the organisms to very low levels. Data from the aquatic model ecosystem demonstrated a good correlation between the partition coefficients of the drugs and their accumulation in the fish. Images FIGURE 1. PMID:1037611

Biodegradation of fluorinated alkyl substances.

PubMed

Frömel, Tobias; Knepper, Thomas P

2010-01-01

The incorporation of fluorine into organic molecules entails both positive and adverse effects. Although fluorine imparts positive and unique properties such as water-and oil-repellency and chemical stability, adverse effects often pervade members of this compound class. A striking property of long perfluoroalkyl chains is their very pronounced environmental persistence. The present review is the first one designed to summarize recent accomplishments in the field of biodegradation of fluorine-containing surfactants, their metabolites, and structural analogs. The pronounced scientific and public interest in these chemicals has given impetus to undertake numerous degradation studies to assess the sources and origins of different fluorinated analog chemical known to exist in the environment. It was shown that biodegradation plays an important role in understanding how fluorinated substances reach the environment and, once they do, what their fate is. Today, PFOS and PFOA are ubiquitously detected as environmental contaminants. Their prominence as contaminants is mainly due to their extreme persistence, which is linked to their perfluoroalkyl chain length. It appears that desulfonation of a highly fluorinated surfactants can be achieved if an α-situated H atom, in relation to the sulfonate group, is present, at least under sulfur-limiting conditions. Molecules that are less heavily fluorinated can show very complex metabolic behavior, as is the case for fluorotelomer alcohols. These compounds are degraded via different but simultaneous pathways, which produce different stable metabolites, one of which is the respective perfluoroalkanoate (8:2-FTOH is transformed to PFOA). Preliminary screening tests indicate that fluorinated functional groups, such as the trifluoromethoxy group and the p-(trifluoromethyl)phenoxy group, may be useful implementations in novel, environmentally benign fluorosurfactants. More specifically, trifluoromethoxy groups constitute a substitute for those that have been used in the past; this functionality is degradable when it appears in structures that are normally subject to biodegradation. Other compounds tested did not meet this criterion. Interdisciplinary investigations on fluorinated surfactants are still very much needed and will certainly continue during the next many years. For instance, the role of fluorinated polymers in contributing small fluorinated molecules to the environmental burden still has not been fully understood.

The effect of biodegradation on gammacerane in crude oils.

PubMed

Huang, Haiping

2017-08-01

Gammacerane is one of the major biomarkers widely used in depositional environment diagnosis, oil family classification, and oil-source correlation. It is generally accepted that gammacerane is more resistant to biodegradation than regular hopanes. However, whether it is biodegradable as well has not been reported in literatures. In order to investigate the effect of biodegradation on gammacerane in crude oils, 69 core samples from two biodegraded petroleum accumulations were geochemically characterized by quantitative GC-MS analysis. All samples are originated from lacustrine source rocks in China and have experienced at least level 8 degree of biodegradation on the scale of Peters and Moldowan (The biomarker guide: interpreting molecular fossils in petroleum and ancient sediments, Prentice Hall, Englewood Cliffs, 1993). Both case histories showed the concentration of gammacerane decrease with increasing severity of biodegradation, indicating the destruction of gammacerane by biodegradation. A whole series of 25-norhopanes paralleling the 17α,21β-hopanes (up to C 34 ), together with C 28 18-α-25,30-bisnorneohopane, C 29 25-nordiahopane and C 29 25-norgammacerane, is found in the Liaohe sample suite but C 33 , C 34 25-norhopane and 25-norgammacerane are almost undetectable in the Junggar case. The gammacerane in the Liaohe case study appear to be altered simultaneously with hopanes, although the rate of gammacerane alteration is slower. Its susceptibility to biodegradation is similar to 18α(H)-22,29,30-trisnorneohopane (Ts) and 17α(H)-22,29,30-trisnorhopane (Tm) but more vulnerable than 18α-30-norneohopane (C 29 Ts), 15α-methyl-17α(H)-27-norhopane (C 30 diahopane) and pregnanes. The gammacerane in the Junggar oils appear to be less biodegradable than the Liaohe case history. It was altered simultaneously with pregnanes and C 29 Ts but faster than C 30 diahopane. The present data suggest that biodegradation sequence is not universal since the relative rates of biodegradation of different compound classes depend upon specific environmental conditions. Like the case of hopane demethylation, the mechanism of gammacerane biodegradation is not straightforward. While the conversion of gammacerane to 25-norgammacerane is not quantitatively balanced in the Liaohe case history, no 25-norgammacerane has been formed from the degradation of gammacerane in the Junggar case history. The ratio of gammacerane to regular hopanes increases with biodegradation degree especially at extreme levels of degradation, gammacerane index is no longer valid for depositional environment assessment or oil-source correlation.

Identification of Biomarker Genes To Predict Biodegradation of 1,4-Dioxane

PubMed Central

Gedalanga, Phillip B.; Pornwongthong, Peerapong; Mora, Rebecca; Chiang, Sheau-Yun Dora; Baldwin, Brett; Ogles, Dora

2014-01-01

Bacterial multicomponent monooxygenase gene targets in Pseudonocardia dioxanivorans CB1190 were evaluated for their use as biomarkers to identify the potential for 1,4-dioxane biodegradation in pure cultures and environmental samples. Our studies using laboratory pure cultures and industrial activated sludge samples suggest that the presence of genes associated with dioxane monooxygenase, propane monooxygenase, alcohol dehydrogenase, and aldehyde dehydrogenase are promising indicators of 1,4-dioxane biotransformation; however, gene abundance was insufficient to predict actual biodegradation. A time course gene expression analysis of dioxane and propane monooxygenases in Pseudonocardia dioxanivorans CB1190 and mixed communities in wastewater samples revealed important associations with the rates of 1,4-dioxane removal. In addition, transcripts of alcohol dehydrogenase and aldehyde dehydrogenase genes were upregulated during biodegradation, although only the aldehyde dehydrogenase was significantly correlated with 1,4-dioxane concentrations. Expression of the propane monooxygenase demonstrated a time-dependent relationship with 1,4-dioxane biodegradation in P. dioxanivorans CB1190, with increased expression occurring after over 50% of the 1,4-dioxane had been removed. While the fraction of P. dioxanivorans CB1190-like bacteria among the total bacterial population significantly increased with decrease in 1,4-dioxane concentrations in wastewater treatment samples undergoing active biodegradation, the abundance and expression of monooxygenase-based biomarkers were better predictors of 1,4-dioxane degradation than taxonomic 16S rRNA genes. This study illustrates that specific bacterial monooxygenase and dehydrogenase gene targets together can serve as effective biomarkers for 1,4-dioxane biodegradation in the environment. PMID:24632253

Treatability Study in Support of Intrinsic Remediation for the Jet Fuel Transfer Line Southwest of Building 412 and the POL Yard. Volume 1: Text. Wisconsin Air National Guard at Truax Field, Madison, Wisconsin

DTIC Science & Technology

1997-01-01

Jamison et al., 1975; Atlas , 1981, 1984, 1988; Gibson an( ’)ramanian, 1984; Reinhard et al., 1984; Young, 1984; Bartha , 1986; Wilson , 1986, 1987...Academic Press, New York, 381 p. Atlas , R.M., 1981, Microbial degradation of petroleum hydrocarbons - an environmental 0 perspective: Microbiological Reviews...biodegradation: Microbial Ecology , vol. 12, p. 155-172. Bauman, B, 1991, Biodegradation Research of the American Petroleum Institute. Presented at: In

Biodegradation of DIMP, Dieldrin, Isodrin, DBCP, and PCPMSO in Rocky Mountain Arsenal Soils. Installation Restoration Program, Environmental Technology Development

DTIC Science & Technology

1989-01-01

Number DAAK- 1 1 -85-D-007 Report Number CETHA-TE-CR-89006 January 1989 Prepared for: COMMANDER, U.S. ARMY TOXIC AND HAZARDOUS MATERIALS AGENCY Aberdeen...UNIT Aberdeen Proving Ground, MD 21010-5401 ELEMENT NO. NO. NO. ACCESSION NO. 1 . TITLE (Include Security Classification) - Biodegradation of DIMP...TYPE OF REPORT 113b. TIME COVERED 114. DATE OF REPORT (Year, Month, Day) 15. PAGE COUNT Final I FROM 1 /87 TO_1/89 1989 January 30 6. SUPPLEMENTARY

SITE TECHNOLOGY CAPSULE: ZENOGEM™ WASTEWATER TREATMENT PROCESS

EPA Science Inventory

Zenon Environmental System's ZenoGem™ Wastewater Treatment Process treats aqueous media contaminated with volatile/semi-volatile organic compounds. This technology combines aerobic biological treatment to remove biodegradable organic compounds with ultrafiltration to separate res...

Tiles of Horror: Cleaning the Bathroom.

ERIC Educational Resources Information Center

Dickey, Philip

1993-01-01

Discusses health risks and environmental repercussions associated with household disinfectants and cleaners. Provides alternatives that meet the "Green Cross" certification for biodegradability and safety. A chart lists hazardous ingredients in common household cleaning products. (MCO)

Anaerobic biodegradation of (emerging) organic contaminants in the aquatic environment.

PubMed

Ghattas, Ann-Kathrin; Fischer, Ferdinand; Wick, Arne; Ternes, Thomas A

2017-06-01

Although strictly anaerobic conditions prevail in several environmental compartments, up to now, biodegradation studies with emerging organic contaminants (EOCs), such as pharmaceuticals and personal care products, have mainly focused on aerobic conditions. One of the reasons probably is the assumption that the aerobic degradation is more energetically favorable than degradation under strictly anaerobic conditions. Certain aerobically recalcitrant contaminants, however, are biodegraded under strictly anaerobic conditions and little is known about the organisms and enzymatic processes involved in their degradation. This review provides a comprehensive survey of characteristic anaerobic biotransformation reactions for a variety of well-studied, structurally rather simple contaminants (SMOCs) bearing one or a few different functional groups/structural moieties. Furthermore it summarizes anaerobic degradation studies of more complex contaminants with several functional groups (CMCs), in soil, sediment and wastewater treatment. While strictly anaerobic conditions are able to promote the transformation of several aerobically persistent contaminants, the variety of observed reactions is limited, with reductive dehalogenations and the cleavage of ether bonds being the most prevalent. Thus, it becomes clear that the transferability of degradation mechanisms deduced from culture studies of SMOCs to predict the degradation of CMCs, such as EOCs, in environmental matrices is hampered due the more complex chemical structure bearing different functional groups, different environmental conditions (e.g. matrix, redox, pH), the microbial community (e.g. adaptation, competition) and the low concentrations typical for EOCs. Copyright © 2017 The Authors. Published by Elsevier Ltd.. All rights reserved.

Pathways for degradation of plastic polymers floating in the marine environment.

PubMed

Gewert, Berit; Plassmann, Merle M; MacLeod, Matthew

2015-09-01

Each year vast amounts of plastic are produced worldwide. When released to the environment, plastics accumulate, and plastic debris in the world's oceans is of particular environmental concern. More than 60% of all floating debris in the oceans is plastic and amounts are increasing each year. Plastic polymers in the marine environment are exposed to sunlight, oxidants and physical stress, and over time they weather and degrade. The degradation processes and products must be understood to detect and evaluate potential environmental hazards. Some attention has been drawn to additives and persistent organic pollutants that sorb to the plastic surface, but so far the chemicals generated by degradation of the plastic polymers themselves have not been well studied from an environmental perspective. In this paper we review available information about the degradation pathways and chemicals that are formed by degradation of the six plastic types that are most widely used in Europe. We extrapolate that information to likely pathways and possible degradation products under environmental conditions found on the oceans' surface. The potential degradation pathways and products depend on the polymer type. UV-radiation and oxygen are the most important factors that initiate degradation of polymers with a carbon-carbon backbone, leading to chain scission. Smaller polymer fragments formed by chain scission are more susceptible to biodegradation and therefore abiotic degradation is expected to precede biodegradation. When heteroatoms are present in the main chain of a polymer, degradation proceeds by photo-oxidation, hydrolysis, and biodegradation. Degradation of plastic polymers can lead to low molecular weight polymer fragments, like monomers and oligomers, and formation of new end groups, especially carboxylic acids.

Application of stable isotope ratio analysis for biodegradation monitoring in groundwater

USGS Publications Warehouse

Hatzinger, Paul B.; Böhlke, John Karl; Sturchio, Neil C.

2013-01-01

Stable isotope ratio analysis is increasingly being applied as a tool to detect, understand, and quantify biodegradation of organic and inorganic contaminants in groundwater. An important feature of this approach is that it allows degradative losses of contaminants to be distinguished from those caused by non-destructive processes such as dilution, dispersion, and sorption. Recent advances in analytical techniques, and new approaches for interpreting stable isotope data, have expanded the utility of this method while also exposing complications and ambiguities that must be considered in data interpretations. Isotopic analyses of multiple elements in a compound, and multiple compounds in the environment, are being used to distinguish biodegradative pathways by their characteristic isotope effects. Numerical models of contaminant transport, degradation pathways, and isotopic composition are improving quantitative estimates of in situ contaminant degradation rates under realistic environmental conditions.

Multi-element isotope fractionation concepts to characterize the biodegradation of hydrocarbons - from enzymes to the environment.

PubMed

Vogt, Carsten; Dorer, Conrad; Musat, Florin; Richnow, Hans-Hermann

2016-10-01

Multi-element compound-specific isotope fractionation (ME-CSIA) has become a state-of-the-art approach for identifying biotransformation reactions. In the last decade, several studies focused on the combined analysis of carbon and hydrogen stable isotopes upon biodegradation of hydrocarbons due to its widespread environmental occurrence as contaminants, often in high concentrations. Most known initial transformation reactions of hydrocarbons have been isotopically characterized in laboratory experiments using model cultures. The data suggest that several of these reactions - especially those occurring under anoxic conditions - can be identified by ME-CSIA, although a number of constraints have been realized which may lead to wrong ME-CSIA data interpretations in field studies. Generally, the applicability of ME-CSIA regarding hydrocarbon biodegradation needs to be corroborated in future field studies. Copyright © 2016 Elsevier Ltd. All rights reserved.

Biodegradation screening of chemicals in an artificial matrix simulating the water-sediment interface.

PubMed

Baginska, Ewelina; Haiß, Annette; Kümmerer, Klaus

2015-01-01

Biodegradation is the most important attenuation process for most of organic chemicals in the environment. This process decides whether the organic substance itself or its degradation products rests in the environment and should be considered for a further risk assessment. This work presents the development of a water sediment screening test, based on OECD guideline 308, with a high significance to environmental conditions and with a good reproducibility and consistency of results. The increased reproducibility was achieved by creating an artificial and standardized medium, based on the existing OECD guidelines OECD 302C, 301D and 218. Each test consisted of five different series: blank, quality control, test, toxicity control and abiotic control. Biodegradation was assessed by measurement of pressure difference in closed vessels using the OxiTop(®) system. Aniline, diethylene glycol and sodium acetate were used to optimize and validate test conditions. Additionally, two pharmaceuticals: Acetaminophen and ciprofloxacin (CIP) were tested as an example of possible test application. Acetaminophen was mainly removed from the system by biodegradation whereas CIP was removed from water phase by sorption onto sediment. Water sediment test proved to be a promising tool for the biodegradation investigation of chemicals in the water-sediment interface. Copyright © 2014 Elsevier Ltd. All rights reserved.

Biodegradation of 17β-estradiol, estrone and testosterone in stream sediments

USGS Publications Warehouse

Bradley, Paul M.; Barber, Larry B.; Chapelle, Francis H.; Gray, James L.; Kolpin, Dana W.; McMahon, Peter B.

2009-01-01

Biodegradation of 17β-estradiol (E2), estrone (E1), and testosterone (T) was investigated in three wastewater treatment plant (WWTP) affected streams in the United States. Relative differences in the mineralization of [4-14C] substrates were assessed in oxic microcosms containing saturated sediment or water-only from locations upstream and downstream of the WWTP outfall in each system. Upstream sediment demonstrated significant mineralization of the “A” ring of E2, E1, and T, with biodegradation of T consistently greater than that of E2 and no systematic difference in E2 and E1 biodegradation. “A” ring mineralization also was observed in downstream sediment, with E1 and T mineralization being substantially depressed relative to upstream samples. In marked contrast, E2 mineralization in sediment immediately downstream from the WWTP outfalls was more than double that in upstream sediment. E2 mineralization was observed in water, albeit at insufficient rate to prevent substantial downstream transport. The results indicate that, in combination with sediment sorption processes which effectively scavenge hydrophobic contaminants from the water column and immobilize them in the vicinity of the WWTP outfall, aerobic biodegradation of reproductive hormones can be an environmentally important mechanism for nonconservative (destructive) attenuation of hormonal endocrine disruptors in effluent-affected streams.

Biodegradable hydrogel derived from cellulose acetate and EDTA as a reduction substrate of leaching NPK compound fertilizer and water retention in soil.

PubMed

Senna, André M; Botaro, Vagner R

2017-08-28

To study the behavior of a biodegradable hydrogel derived from cellulose acetate and ethylenediaminetetraacetic dianhydride (EDTAD), as a reduction substrate of NPK fertilizer in soil. The biodegradable hydrogel (HEDTA) was prepared from cellulose acetate (CA) with a degree substitution (DS) 2.5 by esterification crosslinking with EDTAD catalyzed by triethylamine. We systematically investigated the performance of the HEDTA in the reducing NPK (Ammonium, phosphate and potassium) fertilizer leaching. We also compare the percentage of leaching between the HEDTA and commercial fertilizers. To characterize the esterification and crosslinking between CA and EDTAD, FTIR spectroscopy and thermogravimetric analysis (DTG) were employed. The biodegradation experiments were carried out in simulated soil (23% of sand, 23% of cattle manure, 23% of soil and 31% of water) and the HEDTA was tested in the eucalyptus planting during the dry season in the São Paulo state, Brazil. The HEDTA was able to reduce the leaching of fertilizers and improve the performance of eucalyptus seedlings and reduced the mortality of the seedlings. The HEDTA showed to be an excellent substrate for slow release and water-retention in soil, reducer of the fertilizers leaching, in addition being nontoxic, biodegradable in the soil and environmentally-friendly. Copyright © 2017 Elsevier B.V. All rights reserved.

Anoxic biodegradation of triclosan and the removal of its antimicrobial effect in microbial fuel cells.

PubMed

Wang, Lu; Liu, Yulei; Wang, Chao; Zhao, Xiaodan; Mahadeva, Gurumurthy Dummi; Wu, Yicheng; Ma, Jun; Zhao, Feng

2018-02-15

Triclosan (TCS) is an emerging organic contaminant in the environment. Here, the anoxic bio-degradation of TCS in microbial fuel cells (MFCs) was explored. It was found that anoxic biodegradation of TCS could be achieved in MFC, and the removal rate of TCS was accelerated after reactor acclimation. After 7 months of operation, 10mg/L TCS could be removed within 8days in MFCs. Fluorescence microscopy results revealed that the microbe cells in the reactors were intact, and the microbes were in active state. Flow cytometry test showed that the proliferation of inoculated microbe was higher in MFC effluent than that in TCS solution. These data indicate that the biotoxicity of TCS has been largely eliminated after the treatment. The microbial community shift during the TCS degradation process was investigated as well. Species such as Geothrix, Corynebacterium, Sulfobacillus, GOUTA19, Geobacter, Acidithiobacillus and Acinetobacter, which were capable for the degradation of benzene-related and dechlorination of chlorine-containing chemicals, were flourished in the electrode biofilm. They may participate in the biodegradation of TCS. This work provides a new perspective for the anoxic biodegradation of recalcitrant organics, and can be useful for the in-situ bioremediation of environmental pollutants with the removal of their biotoxicity. Copyright © 2017. Published by Elsevier B.V.

Biodegradation mechanism of 1H-1,2,4-triazole by a newly isolated strain Shinella sp. NJUST26

PubMed Central

Wu, Haobo; Shen, Jinyou; Wu, Ruiqin; Sun, Xiuyun; Li, Jiansheng; Han, Weiqing; Wang, Lianjun

2016-01-01

The highly recalcitrant 1H-1,2,4-triazole (TZ) is widely used in the synthesis of agricultural pesticide and considered to be an environmental pollutant. In this study, a novel strain NJUST26 capable of utilizing TZ as the sole carbon and nitrogen source, was isolated from TZ-contaminated soil, and identified as Shinella sp. The biodegradation assays suggested that optimal temperature and pH for TZ degradation by NJUST26 were 30 °C and 6–7, respectively. With the increase of initial TZ concentration from 100 to 320 mg L−1, the maximum volumetric degradation rate increased from 29.06 to 82.96 mg L−1 d−1, indicating high tolerance of NJUST26 towards TZ. TZ biodegradation could be accelerated through the addition of glucose, sucrose and yeast extract at relatively low dosage. The main metabolites, including 1,2-dihydro-3H-1,2,4-triazol-3-one (DHTO), semicarbazide and urea were identified. Based on these results, biodegradation pathway of TZ by NJUST26 was proposed, i.e., TZ was firstly oxidized to DHTO, and then the cleavage of DHTO ring occurred to generate N-hydrazonomethyl-formamide, which could be further degraded to biodegradable semicarbazide and urea. PMID:27436634

The Effects of Biodegradation and Photodegradation on DOM Optical Properties: Controlled Laboratory Study Using Plant, Soil and Algal Leachates

NASA Astrophysics Data System (ADS)

Hansen, A. M.; Kraus, T. E. C.; Pellerin, B. A.; Fleck, J.

2014-12-01

Many studies use optical properties to infer dissolved organic matter (DOM) composition and origin; however, there are few controlled studies which examine the effects of environmental processing on different DOM sources. Our goal was to better understand the roles DOM plays in wetland environments of the Sacramento-San Joaquin Delta. Therefore, five endmember sources of DOM from this region were selected for use in this study: peat soil (euic, thermic Typic Medisaprists); three aquatic macrophytes (white rice (Oryza sativa); tule (Schoenoplectus acutus); cattail (Typha spp.)); and one diatom (Thalassiosira weissflogii). We measured DOM concentrations (mg C/L) and optical properties (absorbance and fluorescence) of these sources following biological and photochemical degradation over a three month period. DOM concentration decreased by over 90% in plant and algal leachates following 3 months of biodegradation, while photoexposure had negligible effects. The fluorescence index (FI), humic index (HI), specific UV absorbance at 254 nm (SUVA), and carbon-normalized fluorescence of Peaks C and A increased with biodegradation, whereas Peak T decreased. Photoexposure resulted in a decrease of the FI, HI and SUVA values. Our results emphasize the need to better understand how environmental processing affects DOM properties in aquatic environments; the frequently opposing effects of biodegradation and photodegradation, which occur simultaneously in nature, make it challenging to decipher the original DOM source without considering multiple parameters. This dataset can help us better identify which optical properties, either individual or in combination, can provide insight into how biogeochemical processes affect DOM in aquatic environments.

Natural biopolimers in organic food packaging

NASA Astrophysics Data System (ADS)

Wieczynska, Justyna; Cavoski, Ivana; Chami, Ziad Al; Mondelli, Donato; Di Donato, Paola; Di Terlizzi, Biagio

2014-05-01

Concerns on environmental and waste problems caused by use of non-biodegradable and non-renewable based plastic packaging have caused an increase interest in developing biodegradable packaging using renewable natural biopolymers. Recently, different types of biopolymers like starch, cellulose, chitosan, casein, whey protein, collagen, egg white, soybean protein, corn zein, gelatin and wheat gluten have attracted considerable attention as potential food packaging materials. Recyclable or biodegradable packaging material in organic processing standards is preferable where possible but specific principles of packaging are not precisely defined and standards have to be assessed. There is evidence that consumers of organic products have specific expectations not only with respect to quality characteristics of processed food but also in social and environmental aspects of food production. Growing consumer sophistication is leading to a proliferation in food eco-label like carbon footprint. Biopolymers based packaging for organic products can help to create a green industry. Moreover, biopolymers can be appropriate materials for the development of an active surfaces designed to deliver incorporated natural antimicrobials into environment surrounding packaged food. Active packaging is an innovative mode of packaging in which the product and the environment interact to prolong shelf life or enhance safety or sensory properties, while maintaining the quality of the product. The work will discuss the various techniques that have been used for development of an active antimicrobial biodegradable packaging materials focusing on a recent findings in research studies. With the current focus on exploring a new generation of biopolymer-based food packaging materials with possible applications in organic food packaging. Keywords: organic food, active packaging, biopolymers , green technology

Biodegradation of different petroleum hydrocarbons by free and immobilized microbial consortia.

PubMed

Shen, Tiantian; Pi, Yongrui; Bao, Mutai; Xu, Nana; Li, Yiming; Lu, Jinren

2015-12-01

The efficiencies of free and immobilized microbial consortia in the degradation of different types of petroleum hydrocarbons were investigated. In this study, the biodegradation rates of naphthalene, phenanthrene, pyrene and crude oil reached about 80%, 30%, 56% and 48% under the optimum environmental conditions of free microbial consortia after 7 d. We evaluated five unique co-metabolic substances with petroleum hydrocarbons, α-lactose was the best co-metabolic substance among glucose, α-lactose, soluble starch, yeast powder and urea. The orthogonal biodegradation analysis results showed that semi-coke was the best immobilized carrier followed by walnut shell and activated carbon. Meanwhile, the significance of various factors that contribute to the biodegradation of semi-coke immobilized microbial consortia followed the order of: α-lactose > semi-coke > sodium alginate > CaCl2. Moreover, the degradation rate of the immobilized microbial consortium (47%) was higher than that of a free microbial consortium (26%) under environmental conditions such as the crude oil concentration of 3 g L(-1), NaCl concentration of 20 g L(-1), pH at 7.2-7.4 and temperature of 25 °C after 5 d. SEM and FTIR analyses revealed that the structure of semi-coke became more porous and easily adhered to the microbial consortium; the functional groups (e.g., hydroxy and phosphate) were identified in the microbial consortium and were changed by immobilization. This study demonstrated that the ability of microbial adaptation to the environment can be improved by immobilization which expands the application fields of microbial remediation.

Assessing the biodegradability of microparticles disposed down the drain.

PubMed

McDonough, Kathleen; Itrich, Nina; Casteel, Kenneth; Menzies, Jennifer; Williams, Tom; Krivos, Kady; Price, Jason

2017-05-01

Microparticles made from naturally occurring materials or biodegradable plastics such as poly(3-hydroxy butyrate)-co-(3-hydroxy valerate), PHBV, are being evaluated as alternatives to microplastics in personal care product applications but limited data is available on their ultimate biodegradability (mineralization) in down the drain environmental compartments. An OECD 301B Ready Biodegradation Test was used to quantify ultimate biodegradability of microparticles made of PHBV foam, jojoba wax, beeswax, rice bran wax, stearyl stearate, blueberry seeds and walnut shells. PHBV polymer was ready biodegradable reaching 65.4 ± 4.1% evolved CO 2 in 5 d and 90.5 ± 3.1% evolved CO 2 in 80 d. PHBV foam microparticles (125-500 μm) were mineralized extensively with >66% CO 2 evolution in 28 d and >82% CO 2 evolution in 80 d. PHBV foam microparticles were mineralized at a similar rate and extent as microparticles made of jojoba wax, beeswax, rice bran wax, and stearyl stearate which reached 84.8  ± 4.8, 84.9  ± 2.2, 82.7  ± 4.7, and 86.4 ± 3.2% CO 2 evolution respectively in 80 d. Blueberry seeds and walnut shells mineralized more slowly only reaching 39.3  ± 6.9 and 5.1 ± 2.8% CO 2 evolution in 80 d respectively. Copyright © 2017 Elsevier Ltd. All rights reserved.

Influence of ozonation and biodegradation on toxicity of industrial textile wastewater.

PubMed

Paździor, Katarzyna; Wrębiak, Julita; Klepacz-Smółka, Anna; Gmurek, Marta; Bilińska, Lucyna; Kos, Lech; Sójka-Ledakowicz, Jadwiga; Ledakowicz, Stanisław

2017-06-15

The textile industry demands huge volumes of high quality water which converts into wastewater contaminated by wide spectrum of chemicals. Estimation of textile wastewater influence on the aquatic systems is a very important issue. Therefore, closing of the water cycle within the factories is a promising method of decreasing its environmental impact as well as operational costs. Taking both reasons into account, the aim of this work was to establish the acute toxicity of the textile wastewater before and after separate chemical, biological as well as combined chemical-biological treatment. For the first time the effects of three different combinations of chemical and biological methods were investigated. The acute toxicity analysis were evaluated using the Microtox ® toxicity test. Ozonation in two reactors of working volume 1 dm 3 (stirred cell) and 20 dm 3 (bubble column) were tested as chemical process, while biodegradation was conducted in two, different systems - Sequence Batch Reactors (SBR; working volume 1.5 dm 3 ) and Horizontal Continuous Flow Bioreactor (HCFB; working volume 12 dm 3 ). The untreated wastewater had the highest toxicity (EC50 value in range: 3-6%). Ozonation caused lower reduction of the toxicity than biodegradation. In the system with SBR the best results were obtained for the biodegradation followed by the ozonation and additional biodegradation - 96% of the toxicity removal. In the second system (with HCFB) two-stage treatment (biodegradation followed by the ozonation) led to the highest toxicity reduction (98%). Copyright © 2016 Elsevier Ltd. All rights reserved.

Paracetamol in the environment and its degradation by microorganisms.

PubMed

Wu, Shijin; Zhang, Lili; Chen, Jianmeng

2012-11-01

Paracetamol (4'-hydroxyacetanilide, N-acetyl-p-aminophenol, acetaminophen, and paracetamol) is a widely used over-the-counter analgesic and antipyretic drug. Paracetamol and structural analogs are ubiquitous in the natural environment and easily accumulate in aquatic environment, which have been detected in surface waters, wastewater, and drinking water throughout the world. Paracetamol wastewater is mainly treated by chemical oxidation processes. Although these chemical methods may be available for treating these pollutants, the harsh reaction conditions, the generation of secondary pollutants, and the high operational cost associated with these methods have often made them not a desirable choice. Biodegradation of paracetamol is being considered as an environmentally friendly and low-cost option. The goal of this review is to provide an outline of the current knowledge of biodegradation of paracetamol in the occurrence, degrading bacteria, and proposed metabolic/biodegrading pathways, enzymes and possible intermediates. The comprehensive understanding of the metabolic pathways and enzyme systems involved in the utilization of paracetamol means will be helpful for optimizing and allowing rational design of biodegradation systems for paracetamol-contaminated wastewater.

Conventional and improved cytotoxicity test methods of newly developed biodegradable magnesium alloys

NASA Astrophysics Data System (ADS)

Han, Hyung-Seop; Kim, Hee-Kyoung; Kim, Yu-Chan; Seok, Hyun-Kwang; Kim, Young-Yul

2015-11-01

Unique biodegradable property of magnesium has spawned countless studies to develop ideal biodegradable orthopedic implant materials in the last decade. However, due to the rapid pH change and extensive amount of hydrogen gas generated during biocorrosion, it is extremely difficult to determine the accurate cytotoxicity of newly developed magnesium alloys using the existing methods. Herein, we report a new method to accurately determine the cytotoxicity of magnesium alloys with varying corrosion rate while taking in-vivo condition into the consideration. For conventional method, extract quantities of each metal ion were determined using ICP-MS and the result showed that the cytotoxicity due to pH change caused by corrosion affected the cell viability rather than the intrinsic cytotoxicity of magnesium alloy. In physiological environment, pH is regulated and adjusted within normal pH (˜7.4) range by homeostasis. Two new methods using pH buffered extracts were proposed and performed to show that environmental buffering effect of pH, dilution of the extract, and the regulation of eluate surface area must be taken into consideration for accurate cytotoxicity measurement of biodegradable magnesium alloys.

Aerobic biotransformation of 3-methylindole to ring cleavage products by Cupriavidus sp. strain KK10.

PubMed

Fukuoka, Kimiko; Ozeki, Yasuhiro; Kanaly, Robert A

2015-09-01

3-Methylindole, also referred to as skatole, is a pollutant of environmental concern due to its persistence, mobility and potential health impacts. Petroleum refining, intensive livestock production and application of biosolids to agricultural lands result in releases of 3-methylindole to the environment. Even so, little is known about the aerobic biodegradation of 3-methylindole and comprehensive biotransformation pathways have not been established. Using glycerol as feedstock, the soil bacterium Cupriavidus sp. strain KK10 biodegraded 100 mg/L of 3-methylindole in 24 h. Cometabolic 3-methylindole biodegradation was confirmed by the identification of biotransformation products through liquid chromatography electrospray ionization tandem mass spectrometry analyses. In all, 14 3-methylindole biotransformation products were identified which revealed that biotransformation occurred through different pathways that included carbocyclic aromatic ring-fission of 3-methylindole to single-ring pyrrole carboxylic acids. This work provides first comprehensive evidence for the aerobic biotransformation mechanisms of 3-methylindole by a soil bacterium and expands our understanding of the biodegradative capabilities of members of the genus Cupriavidus towards heteroaromatic pollutants.

Occurrence and Biodegradation of Nonylphenol in the Environment

PubMed Central

Mao, Zhen; Zheng, Xiao-Fei; Zhang, Yan-Qiu; Tao, Xiu-Xiang; Li, Yan; Wang, Wei

2012-01-01

Nonylphenol (NP) is an ultimate degradation product of nonylphenol polyethoxylates (NPE) that is primarily used in cleaning and industrial processes. Its widespread use has led to the wide existence of NP in various environmental matrices, such as water, sediment, air and soil. NP can be decreased by biodegradation through the action of microorganisms under aerobic or anaerobic conditions. Half-lives of biodegradation ranged from a few days to almost one hundred days. The degradation rate for NP was influenced by temperature, pH and additions of yeast extracts, surfactants, aluminum sulfate, acetate, pyruvate, lactate, manganese dioxide, ferric chloride, sodium chloride, hydrogen peroxide, heavy metals, and phthalic acid esters. Although NP is present at low concentrations in the environment, as an endocrine disruptor the risks of long-term exposure to low concentrations remain largely unknown. This paper reviews the occurrence of NP in the environment and its aerobic and anaerobic biodegradation in natural environments and sewage treatment plants, which is essential for assessing the potential risk associated with low level exposure to NP and other endocrine disruptors. PMID:22312266

Analysis, toxicity, occurrence and biodegradation of nonylphenol isomers: a review.

PubMed

Lu, Zhijiang; Gan, Jay

2014-12-01

Over the last two decades, nonylphenols (NPs) have become to be known as a priority hazardous substance due primarily to its estrogenicity and ubiquitous occurrence in the environment. Nonylphenols are commonly treated as a single compound in the evaluation of their environmental occurrence, fate and transport, treatment or toxicity. However, technical nonylphenols (tNPs) are in fact a mixture of more than 100 isomers and congeners. Recent studies showed that some of these isomers behaved significantly differently in occurrence, estrogenicity and biodegradability. The most estrogenic isomer was about 2 to 4 times more active than tNP. Moreover, the half lives of the most recalcitrant isomers were about 3 to 4 times as long as those of readily-biodegradable isomers. Negligence of NP's isomer specificity may result in inaccurate assessment of its ecological and health effects. In this review, we summarized the recent publications on the analysis, occurrence, toxicity and biodegradation of NP at the isomer level and highlighted future research needs to improve our understanding of isomer-specificity of NP. Copyright © 2014. Published by Elsevier Ltd.

Study of microbes having potentiality for biodegradation of plastics.

PubMed

Ghosh, Swapan Kumar; Pal, Sujoy; Ray, Sumanta

2013-07-01

Plastic is a broad name given to the different types of organic polymers having high molecular weight and is commonly derived from different petrochemicals. Plastics are generally not biodegradable or few are degradable but in a very slow rate. Day by day, the global demand of these polymers is sharply increasing; however, considering their abundance and potentiality in causing different environmental hazards, there is a great concern in the possible methods of degradation of plastics. Recently, there have been some debates at the world stage about the potential degradation procedures of these synthetic polymers and microbial degradation has emerged as one of the potential alternative ways of degradation of plastics. Alternatively, some scientists have also reported many adverse effects of these polymers in human health, and thus, there is an immediate need of a potential screening of some potential microbes to degrade these synthetic polymers. In this review, we have taken an attempt to accumulate all information regarding the chemical nature along with some potential microbes and their enzymatic nature of biodegradation of plastics along with some key factors that affect their biodegradability.

Flexible organic light emitting diodes fabricated on biocompatible silk fibroin substrate

NASA Astrophysics Data System (ADS)

Liu, Yuqiang; Xie, Yuemin; Liu, Yuan; Song, Tao; Zhang, Ke-Qin; Liao, Liangsheng; Sun, Baoquan

2015-10-01

Flexible and biodegradable electronics are currently under extensive investigation for biocompatible and environmentally-friendly applications. Synthetic plastic foils are widely used as substrates for flexible electronics. But typical plastic substrates such as polyethylene naphthalate (PEN) could not be degraded in a natural bio-environment. A great demand still exists for a next-generation biocompatible and biodegradable substrate for future application. For example, electronic devices can be potentially integrated into the human body. In this work, we demonstrate that the biocompatible and biodegradable natural silk fibroin (SF) films embedded with silver nanowires (AgNWs) mesh could be employed as conductive transparent substrates to fabricate flexible organic light emitting diodes (OLEDs). Compared with commercial PEN substrates coated with indium tin oxide, the AgNWs/SF composite substrates exhibit a similar sheet resistance of 12 Ω sq-1, a lower surface roughness, as well as a broader light transmission range. Flexible OLEDs based on AgNWs/SF substrates achieve a current efficiency of 19 cd A-1, demonstrating the potential of the flexible AgNWs/SF films as conductive and transparent substrates for next-generation biodegradable devices.

Biodegradation of sulfamethoxazole photo-transformation products in a water/sediment test.

PubMed

Su, Tong; Deng, Huiping; Benskin, Jonathan P; Radke, Michael

2016-04-01

Occurrence of the antibiotic sulfamethoxazole (SMX) in the aquatic environment is of concern due to its potential to induce antibiotic resistance in pathogenic bacteria. While degradation of SMX can occur by numerous processes, the environmental fate of its transformation products (TPs) remains poorly understood. In the present work, biodegradation of SMX photo-TPs was investigated in a water/sediment system. Photo-TPs were produced by exposing SMX to artificial sunlight for 48 h. The resulting mixture of 8 photo-TPs was characterized using a combination of ultra-high performance liquid chromatography coupled to high-resolution mass spectrometry and tandem mass spectrometry, and then used in biodegradation experiments. Significant differences in transformation among SMX photo-TPs were observed in the water/sediment system, with four photo-TPs displaying evidence of biodegradation (dissipation half-lives [DT50] of 39.7 d for 3-amino-5-methylisoxazole, 12.7 d for 4-nitro-sulfamethxoazole, 7.6 d for an SMX isomer and 2.4 d for [C10H13N3O4S]), two displaying primarily abiotic degradation (DT50 of 31 d for sulfanilic acid and 74.9 d for 5-methylisoxazol-3-yl-sulfamate), and two photo-TPs behaving largely recalcitrantly. Remarkably, TPs previously reported to be photo-stable also were persistent in biodegradation experiments. The most surprising observation was an increase in SMX concentrations when the irradiated solution was incubated, which we attribute to back-transformation of certain photo-TPs by sediment bacteria (85% from 4-nitro-sulfamethoxazole). This process could contribute to exposure to SMX in the aquatic environment that is higher than one would expect based on the fate of SMX alone. The results highlight the importance of considering TPs along with their parent compounds when characterizing environmental risks of emerging contaminants. Copyright © 2016 Elsevier Ltd. All rights reserved.

Oxygen and chlorine isotopic fractionation during perchlorate biodegradation: Laboratory results and implications for forensics and natural attenuation studies

USGS Publications Warehouse

Sturchio, N.C.; Böhlke, J.K.; Beloso, Abelardo D.; Streger, S.H.; Heraty, L.J.; Hatzinger, P.B.

2007-01-01

Perchlorate is a widespread environmental contaminant having both anthropogenic and natural sources. Stable isotope ratios of O and Cl in a given sample of perchlorate may be used to distinguish its source(s). Isotopic ratios may also be useful for identifying the extent of biodegradation of perchlorate, which is critical for assessing natural attenuation of this contaminant in groundwater. For this approach to be useful, however, the kinetic isotopic fractionations of O and Cl during perchlorate biodegradation must first be determined as a function of environmental variables such as temperature and bacterial species. A laboratory study was performed in which the O and Cl isotope ratios of perchlorate were monitored as a function of degradation by two separate bacterial strains (Azospira suillum JPLRND and Dechlorospirillum sp. FBR2) at both 10??C and 22??C with acetate as the electron donor. Perchlorate was completely reduced by both strains within 280 h at 22??C and 615 h at 10??C. Measured values of isotopic fractionation factors were ??18O = -36.6 to -29.0??? and ??37Cl = -14.5 to -11.5???, and these showed no apparent systematic variation with either temperature or bacterial strain. An experiment using 18O-enriched water (??18O = +198???) gave results indistinguishable from those observed in the isotopically normal water (??18O = -8.1???) used in the other experiments, indicating negligible isotope exchange between perchlorate and water during biodegradation. The fractionation factor ratio ??18O/??37Cl was nearly invariant in all experiments at 2.50 ?? 0.04. These data indicate that isotope ratio analysis will be useful for documenting perchlorate biodegradation in soils and groundwater. The establishment of a microbial fractionation factor ratio (??18O/??37Cl) also has significant implications for forensic studies. ?? 2007 American Chemical Society.

Bioproducts fro biorefineries

USDA-ARS?s Scientific Manuscript database

Biorefineries of the future may convert biomass to fuels, chemicals, and materials that are provided today by petroleum refineries. Bioproducts are attractive because they could offer benefits of renewability, environmental and personal safety, and biodegradability or recyclability. However, a gre...

From "farm to fork" strawberry system: current realities and potential innovative scenarios from life cycle assessment of non-renewable energy use and green house gas emissions.

PubMed

Girgenti, Vincenzo; Peano, Cristiana; Baudino, Claudio; Tecco, Nadia

2014-03-01

In this study, we analysed the environmental profile of the strawberry industry in Northern Italy. The analysis was conducted using two scenarios as reference systems: strawberry crops grown in unheated plastic tunnels using currently existing cultivation techniques, post-harvest management practices and consumption patterns (scenario 1) and the same strawberry cultivation chain in which some of the materials used were replaced with bio-based materials (scenario 2). In numerous studies, biodegradable polymers have been shown to be environmentally friendly, thus potentially reducing environmental impacts. These materials can be recycled into carbon dioxide and water through composting. Many materials, such as Mater-BI® and PLA®, are also derived from renewable resources. The methodology chosen for the environmental analysis was a life cycle assessment (LCA) based on a consequential approach developed to assess a product's overall environmental impact from the production system to its usage and disposal. In the field stage, a traditional mulching film (non-biodegradable) could be replaced with a biodegradable product. This change would result in waste production of 0 kg/ha for the bio-based product compared to 260 kg/ha of waste for polyethylene (PE). In the post-harvest stage, the issue addressed was the use and disposal of packaging materials. The innovative scenario evaluated herein pertains to the use of new packaging materials that increase the shelf life of strawberries, thereby decreasing product losses while increasing waste management efficiency at the level of a distribution platform and/or sales outlet. In the event of product deterioration or non-sale of the product, the packaging and its contents could be collected together as organic waste without any additional processes because the packaging is compostable according to EN13432. Scenario 2 would achieve reductions of 20% in the global warming potential and non-renewable energy impact categories. Copyright © 2013 Elsevier B.V. All rights reserved.

Quantification of in Situ Biodegradation Rate Constants Using a Novel Combined Isotope Approach

NASA Astrophysics Data System (ADS)

Blum, P.; Sültenfuß, J.; Martus, P.

2014-12-01

Numerous studies have shown the enormous potential of the compound-specific isotope analysis (CSIA) for studying the biodegradation of organic compounds such as monoaromatic hydrocarbons (BTEX), polyaromatic hydrocarbons (PAH), chlorinated solvents and other organic contaminants and environmental transformation mechanisms in groundwater. In addition, two-dimensional isotope analysis such as carbon and hydrogen have been successfully studied indicating the potential to also investigate site-specific reaction mechanisms. The main objective of the current study however is to quantify real effective in situ biodegradation rate constants in a coal-tar contaminated aquifer by combining compound-specific isotope analysis (CSIA) and tracer-based (3H-3He) ground-water dating (TGD). Hence, groundwater samples are used to determine groundwater residence times, and carbon and hydrogen stable isotopes are analyzed for selected BTEX and PAH. The results of the hydrogen stable isotopes surprisingly indicate no isotope fractionation and therefore no biodegradation. In contrast, for stable carbon isotopes of selected BTEX such as o-xylene and toluene, isotope shifts are detected indicating active biodegradation under sulfate-reducing conditions. These and previous results of stable carbon isotopes show that only for o-xylene a clear evidence for biodegradation is possible for the studied site. Nevertheless, in combining these results with the groundwater residence times, which range between 1 year for the shallow wells (20 m below surface) and 41 years for the deeper wells (40 m below surface), it is feasible to effectively determine in situ biodegradation rate constants for o-xylene. Conversely, the outcome also evidently demonstrate the major limitations of the novel combined isotope approach for a successful implementation of monitored natural attenuation (MNA) at such field sites.

Microbial enhanced heavy crude oil recovery through biodegradation using bacterial isolates from an Omani oil field.

PubMed

Al-Sayegh, Abdullah; Al-Wahaibi, Yahya; Al-Bahry, Saif; Elshafie, Abdulkadir; Al-Bemani, Ali; Joshi, Sanket

2015-09-16

Biodegradation is a cheap and environmentally friendly process that could breakdown and utilizes heavy crude oil (HCO) resources. Numerous bacteria are able to grow using hydrocarbons as a carbon source; however, bacteria that are able to grow using HCO hydrocarbons are limited. In this study, HCO degrading bacteria were isolated from an Omani heavy crude oil field. They were then identified and assessed for their biodegradation and biotransformation abilities under aerobic and anaerobic conditions. Bacteria were grown in five different minimum salts media. The isolates were identified by MALDI biotyper and 16S rRNA sequencing. The nucleotide sequences were submitted to GenBank (NCBI) database. The bacteria were identified as Bacillus subtilis and B. licheniformis. To assess microbial growth and biodegradation of HCO by well-assay on agar plates, samples were collected at different intervals. The HCO biodegradation and biotransformation were determined using GC-FID, which showed direct correlation of microbial growth with an increased biotransformation of light hydrocarbons (C12 and C14). Among the isolates, B. licheniformis AS5 was the most efficient isolate in biodegradation and biotransformation of the HCO. Therefore, isolate AS5 was used for heavy crude oil recovery experiments, in core flooding experiments using Berea core plugs, where an additional 16 % of oil initially in place was recovered. This is the first report from Oman for bacteria isolated from an oil field that were able to degrade and transform HCO to lighter components, illustrating the potential use in HCO recovery. The data suggested that biodegradation and biotransformation processes may lead to additional oil recovery from heavy oil fields, if bacteria are grown in suitable medium under optimum growth conditions.

Cloning and expression of vgb gene in Bacillus cereus, improve phenol and p-nitrophenol biodegradation

NASA Astrophysics Data System (ADS)

Vélez-Lee, Angel Eduardo; Cordova-Lozano, Felipe; Bandala, Erick R.; Sanchez-Salas, Jose Luis

2016-02-01

In this work, the vgb gene from Vitrocilla stercoraria was used to genetically modify a Bacillus cereus strain isolated from pulp and paper wastewater effluent. The gene was cloned in a multicopy plasmid (pUB110) or uni-copy gene using a chromosome integrative vector (pTrpBG1). B. cereus and its recombinant strains were used for phenol and p-nitrophenol biodegradation using aerobic or micro-aerobic conditions and two different temperatures (i.e. 37 and 25 °C). Complete (100%) phenol degradation was obtained for the strain where the multicopy of vgb gene was present, 98% for the strain where uni-copy gene was present and 45% for wild type strain for the same experimental conditions (i.e. 37 °C and aerobic condition). For p-nitrophenol degradation at the same conditions, the strain with the multi-copy vgb gene was capable to achieve 50% of biodegradation, ˜100% biodegradation was obtained using the uni-copy strain and ˜24% for wild type strain. When the micro-aerobic condition was tested, the biodegradation yield showed a significant decreased. The biodegradation trend observed for aerobic was similar for micro-aerobic assessments: the modified strains showed higher degradation rates when compared with wild type strain. For all experimental conditions, the highest p-nitrophenol degradation was observed using the strain with uni-copy of vgb gene. Besides the increase of biodegradative capability of the strain, insertion of the vgb gene was observed able to modify other morphological characteristics such as avoiding the typical flake formation in the B. cereus culture. In both cases, the modification seems to be related with the enhancement of oxygen supply to the cells generated by the vgb gene insertion. The application of the genetically modified microorganism (GMM) to the biodegradation of pollutants in contaminated water possesses high potential as an environmentally friendly technology to facing this emergent problem.

Potential of vegetable oils for lubricants

USDA-ARS?s Scientific Manuscript database

Vegetable oils offer significant advantages in terms of resource renewability, biodegradability, and comparable performance properties to petroleum-based products. The petroleum-based lubricants render unfavorable impact on the environment. With the growing environmental concerns, seed oils are find...

Biodegradation of Mycotoxins: Tales from Known and Unexplored Worlds

PubMed Central

Vanhoutte, Ilse; Audenaert, Kris; De Gelder, Leen

2016-01-01

Exposure to mycotoxins, secondary metabolites produced by fungi, may infer serious risks for animal and human health and lead to economic losses. Several approaches to reduce these mycotoxins have been investigated such as chemical removal, physical binding, or microbial degradation. This review focuses on the microbial degradation or transformation of mycotoxins, with specific attention to the actual detoxification mechanisms of the mother compound. Furthermore, based on the similarities in chemical structure between groups of mycotoxins and environmentally recalcitrant compounds, known biodegradation pathways and degrading organisms which hold promise for the degradation of mycotoxins are presented. PMID:27199907

"Green" electronics: biodegradable and biocompatible materials and devices for sustainable future.

PubMed

Irimia-Vladu, Mihai

2014-01-21

"Green" electronics represents not only a novel scientific term but also an emerging area of research aimed at identifying compounds of natural origin and establishing economically efficient routes for the production of synthetic materials that have applicability in environmentally safe (biodegradable) and/or biocompatible devices. The ultimate goal of this research is to create paths for the production of human- and environmentally friendly electronics in general and the integration of such electronic circuits with living tissue in particular. Researching into the emerging class of "green" electronics may help fulfill not only the original promise of organic electronics that is to deliver low-cost and energy efficient materials and devices but also achieve unimaginable functionalities for electronics, for example benign integration into life and environment. This Review will highlight recent research advancements in this emerging group of materials and their integration in unconventional organic electronic devices.

Metagenomic Analyses Reveal That Energy Transfer Gene Abundances Can Predict the Syntrophic Potential of Environmental Microbial Communities.

PubMed

Oberding, Lisa; Gieg, Lisa M

2016-01-05

Hydrocarbon compounds can be biodegraded by anaerobic microorganisms to form methane through an energetically interdependent metabolic process known as syntrophy. The microorganisms that perform this process as well as the energy transfer mechanisms involved are difficult to study and thus are still poorly understood, especially on an environmental scale. Here, metagenomic data was analyzed for specific clusters of orthologous groups (COGs) related to key energy transfer genes thus far identified in syntrophic bacteria, and principal component analysis was used in order to determine whether potentially syntrophic environments could be distinguished using these syntroph related COGs as opposed to universally present COGs. We found that COGs related to hydrogenase and formate dehydrogenase genes were able to distinguish known syntrophic consortia and environments with the potential for syntrophy from non-syntrophic environments, indicating that these COGs could be used as a tool to identify syntrophic hydrocarbon biodegrading environments using metagenomic data.

Fractionation of stable isotopes in perchlorate and nitrate during in situ biodegradation in a sandy aquifer

USGS Publications Warehouse

Hatzinger, P.B.; Böhlke, J.K.; Sturchio, N.C.; Gu, B.; Heraty, L.J.; Borden, R.C.

2009-01-01

Environmental context. Perchlorate (ClO4-) and nitrate (NO3-) are common co-contaminants in groundwater, with both natural and anthropogenic sources. Each of these compounds is biodegradable, so in situ enhanced bioremediation is one alternative for treating them in groundwater. Because bacteria typically fractionate isotopes during biodegradation, stable isotope analysis is increasingly used to distinguish this process from transport or mixing-related decreases in contaminant concentrations. However, for this technique to be useful in the field to monitor bioremediation progress, isotope fractionation must be quantified under relevant environmental conditions. In the present study, we quantify the apparent in situ fractionation effects for stable isotopes in ClO4- (Cl and O) and NO3- (N and O) resulting from biodegradation in an aquifer. Abstract. An in situ experiment was performed in a shallow alluvial aquifer in Maryland to quantify the fractionation of stable isotopes in perchlorate (Cl and O) and nitrate (N and O) during biodegradation. An emulsified soybean oil substrate that was previously injected into this aquifer provided the electron donor necessary for biological perchlorate reduction and denitrification. During the field experiment, groundwater extracted from an upgradient well was pumped into an injection well located within the in situ oil barrier, and then groundwater samples were withdrawn for the next 30 h. After correction for dilution (using Br- as a conservative tracer of the injectate), perchlorate concentrations decreased by 78% and nitrate concentrations decreased by 82% during the initial 8.6 h after the injection. The observed ratio of fractionation effects of O and Cl isotopes in perchlorate (18O/37Cl) was 2.6, which is similar to that observed in the laboratory using pure cultures (2.5). Denitrification by indigenous bacteria fractionated O and N isotopes in nitrate at a ratio of ???0.8 (18O/15N), which is within the range of values reported previously for denitrification. However, the magnitudes of the individual apparent in situ isotope fractionation effects for perchlorate and nitrate were appreciably smaller than those reported in homogeneous closed systems (0.2 to 0.6 times), even after adjustment for dilution. These results indicate that (1) isotope fractionation factor ratios (18O/37Cl, 18O/15N) derived from homogeneous laboratory systems (e.g. pure culture studies) can be used qualitatively to confirm the occurrence of in situ biodegradation of both perchlorate and nitrate, but (2) the magnitudes of the individual apparent values cannot be used quantitatively to estimate the in situ extent of biodegradation of either anion. ?? CSIRO 2009.

Study on the biodegradation of crude oil by free and immobilized bacterial consortium in marine environment.

PubMed

Chen, Qingguo; Li, Jingjing; Liu, Mei; Sun, Huiling; Bao, Mutai

2017-01-01

Five strains of bacteria, namely, Exiguobacterium sp. ASW-1, Pseudomonas aeruginosa strain ASW-2, Alcaligenes sp. ASW-3, Alcaligenes sp. ASS-1, and Bacillus sp. ASS-2, were isolated from the Zhejiang coast in China. The mixed flora of the five strains performed well with degrading 75.1% crude oil (1%, w/v) in 7 days. The calcium alginate-activated carbon embedding carrier was used to immobilize bacterial consortium. Immobilized cells performed better than free ones in variations of environmental factors containing incubated temperature, initial pH, salinity of the medium and crude oil concentration. The degradation process of crude oil by immobilized bacteria was accelerated compared with that of the free ones. Bacterial consortium showed better performance on biodegradation of normal alkanes than that of PAHs. Improvement of immobilization on the biodegradation efficiency of normal alkanes (31.9%) was apparently high than that of PAHs (1.9%).

Potential of the green alga Chlorella vulgaris for biodegradation of crude oil hydrocarbons.

PubMed

Xaaldi Kalhor, Aadel; Movafeghi, Ali; Mohammadi-Nassab, Adel Dabbagh; Abedi, Ehsan; Bahrami, Ahmad

2017-10-15

Oil production and/or transportation can cause severe environmental pollution and disrupt the populations of living organisms. In the present study, biodegradation of petroleum hydrocarbons is investigated using Chlorella vulgaris as a green algal species. The microalga was treated by 10 and 20g/l crude oil/water concentrations at two experimental durations (7 and 14days). Based on the results obtained, C. vulgaris owned not only considerable resistance against the pollutants but also high ability in remediation of crude oil hydrocarbons (~94% of the light and ~88% of heavy compounds in 14days). Intriguingly, dry weight of C. vulgaris increased by the rising crude oil concentration indicating the positive effect of crude oil on the growth of the algal species. This biodegradation process is remarkably a continuous progression over a period of time. Copyright © 2017 Elsevier Ltd. All rights reserved.

Green Composites Made of Bamboo Fabric and Poly (Lactic) Acid for Packaging Applications—A Review

PubMed Central

Nurul Fazita, M.R.; Jayaraman, Krishnan; Bhattacharyya, Debes; Mohamad Haafiz, M.K.; Saurabh, Chaturbhuj K.; Hussin, M. Hazwan; H.P.S., Abdul Khalil

2016-01-01

Petroleum based thermoplastics are widely used in a range of applications, particularly in packaging. However, their usage has resulted in soaring pollutant emissions. Thus, researchers have been driven to seek environmentally friendly alternative packaging materials which are recyclable as well as biodegradable. Due to the excellent mechanical properties of natural fibres, they have been extensively used to reinforce biopolymers to produce biodegradable composites. A detailed understanding of the properties of such composite materials is vital for assessing their applicability to various products. The present review discusses several functional properties related to packaging applications in order to explore the potential of bamboo fibre fabric-poly (lactic) acid composites for packaging applications. Physical properties, heat deflection temperature, impact resistance, recyclability and biodegradability are important functional properties of packaging materials. In this review, we will also comprehensively discuss the chronological events and applications of natural fibre biopolymer composites. PMID:28773558

37Cl/35Cl isotope ratio analysis in perchlorate by ion chromatography/multi collector -ICPMS: Analytical performance and implication for biodegradation studies.

PubMed

Zakon, Yevgeni; Ronen, Zeev; Halicz, Ludwik; Gelman, Faina

2017-10-01

In the present study we propose a new analytical method for 37 Cl/ 35 Cl analysis in perchlorate by Ion Chromatography(IC) coupled to Multicollector Inductively Coupled Plasma Mass Spectrometry (MC-ICPMS). The accuracy of the analytical method was validated by analysis of international perchlorate standard materials USGS-37 and USGS -38; analytical precision better than ±0.4‰ was achieved. 37 Cl/ 35 Cl isotope ratio analysis in perchlorate during laboratory biodegradation experiment with microbial cultures enriched from the contaminated soil in Israel resulted in isotope enrichment factor ε 37 Cl = -13.3 ± 1‰, which falls in the range reported previously for perchlorate biodegradation by pure microbial cultures. The proposed analytical method may significantly simplify the procedure for isotope analysis of perchlorate which is currently applied in environmental studies. Copyright © 2017. Published by Elsevier Ltd.

Study on the biodegradation of crude oil by free and immobilized bacterial consortium in marine environment

PubMed Central

Li, Jingjing; Liu, Mei; Sun, Huiling; Bao, Mutai

2017-01-01

Five strains of bacteria, namely, Exiguobacterium sp. ASW-1, Pseudomonas aeruginosa strain ASW-2, Alcaligenes sp. ASW-3, Alcaligenes sp. ASS-1, and Bacillus sp. ASS-2, were isolated from the Zhejiang coast in China. The mixed flora of the five strains performed well with degrading 75.1% crude oil (1%, w/v) in 7 days. The calcium alginate—activated carbon embedding carrier was used to immobilize bacterial consortium. Immobilized cells performed better than free ones in variations of environmental factors containing incubated temperature, initial pH, salinity of the medium and crude oil concentration. The degradation process of crude oil by immobilized bacteria was accelerated compared with that of the free ones. Bacterial consortium showed better performance on biodegradation of normal alkanes than that of PAHs. Improvement of immobilization on the biodegradation efficiency of normal alkanes (31.9%) was apparently high than that of PAHs (1.9%). PMID:28346510

Polyethylene bio-degradation by caterpillars of the wax moth Galleria mellonella.

PubMed

Bombelli, Paolo; Howe, Christopher J; Bertocchini, Federica

2017-04-24

Plastics are synthetic polymers derived from fossil oil and largely resistant to biodegradation. Polyethylene (PE) and polypropylene (PP) represent ∼92% of total plastic production. PE is largely utilized in packaging, representing ∼40% of total demand for plastic products (www.plasticseurope.org) with over a trillion plastic bags used every year [1]. Plastic production has increased exponentially in the past 50 years (Figure S1A in Supplemental Information, published with this article online). In the 27 EU countries plus Norway and Switzerland up to 38% of plastic is discarded in landfills, with the rest utilized for recycling (26%) and energy recovery (36%) via combustion (www.plasticseurope.org), carrying a heavy environmental impact. Therefore, new solutions for plastic degradation are urgently needed. We report the fast bio-degradation of PE by larvae of the wax moth Galleria mellonella, producing ethylene glycol. Copyright © 2017 Elsevier Ltd. All rights reserved.

Biodegradation studies of N4-acetylsulfapyridine and N4-acetylsulfamethazine in environmental water by applying mass spectrometry techniques.

PubMed

García-Galán, María Jesús; Frömel, Tobias; Müller, Jutta; Peschka, Manuela; Knepper, Thomas; Díaz-Cruz, Silvia; Barceló, Damiá

2012-03-01

This work evaluates the biodegradation of N(4)-acetylsulfapyridine (AcSPY) and N(4)-acetylsulfamethazine (AcSMZ), metabolites of two of the most commonly used sulfonamides (SAs) in human and veterinary medicine, respectively. Aerobic transformation in effluent wastewater was simulated using aerated fixed-bed bioreactors. No visible changes in concentration were observed in the AcSMZ reactor after 90 days, whereas AcSPY was fully degraded after 32 days of experiment. It was also demonstrated that AcSPY transformed back to its parent compound sulfapyridine (SPY). The environmental presence of these two metabolites in wastewater effluent had been previously investigated and confirmed, together with three more SA acetylated metabolites and their corresponding parent compounds, in 18 different wastewater treatment plants in Hesse (Germany). Sulfamethoxazole (SMX) and SPY were the two SAs detected most frequently (90% and 89% of the samples, respectively) and in the highest concentrations (682 ng L(-1) for SMX and 532 ng L(-1) for SPY). To conclude, hazard quotients were calculated whenever toxicity data were available. None of the SAs studied posed an environmental risk.

New Concepts in the Evaluation of Biodegradation/Persistence of Chemical Substances Using a Microbial Inoculum

PubMed Central

Thouand, Gérald; Durand, Marie-José; Maul, Armand; Gancet, Christian; Blok, Han

2011-01-01

The European REACH Regulation (Registration, Evaluation, Authorization of CHemical substances) implies, among other things, the evaluation of the biodegradability of chemical substances produced by industry. A large set of test methods is available including detailed information on the appropriate conditions for testing. However, the inoculum used for these tests constitutes a “black box.” If biodegradation is achievable from the growth of a small group of specific microbial species with the substance as the only carbon source, the result of the test depends largely on the cell density of this group at “time zero.” If these species are relatively rare in an inoculum that is normally used, the likelihood of inoculating a test with sufficient specific cells becomes a matter of probability. Normally this probability increases with total cell density and with the diversity of species in the inoculum. Furthermore the history of the inoculum, e.g., a possible pre-exposure to the test substance or similar substances will have a significant influence on the probability. A high probability can be expected for substances that are widely used and regularly released into the environment, whereas a low probability can be expected for new xenobiotic substances that have not yet been released into the environment. Be that as it may, once the inoculum sample contains sufficient specific degraders, the performance of the biodegradation will follow a typical S shaped growth curve which depends on the specific growth rate under laboratory conditions, the so called F/M ratio (ratio between food and biomass) and the more or less toxic recalcitrant, but possible, metabolites. Normally regulators require the evaluation of the growth curve using a simple approach such as half-time. Unfortunately probability and biodegradation half-time are very often confused. As the half-time values reflect laboratory conditions which are quite different from environmental conditions (after a substance is released), these values should not be used to quantify and predict environmental behavior. The probability value could be of much greater benefit for predictions under realistic conditions. The main issue in the evaluation of probability is that the result is not based on a single inoculum from an environmental sample, but on a variety of samples. These samples can be representative of regional or local areas, climate regions, water types, and history, e.g., pristine or polluted. The above concept has provided us with a new approach, namely “Probabio.” With this approach, persistence is not only regarded as a simple intrinsic property of a substance, but also as the capability of various environmental samples to degrade a substance under realistic exposure conditions and F/M ratio. PMID:21863143

Occurrence of 4-tert-butylphenol (4-t-BP) biodegradation in an aquatic sample caused by the presence of Spirodela polyrrhiza and isolation of a 4-t-BP-utilizing bacterium.

PubMed

Ogata, Yuka; Toyama, Tadashi; Yu, Ning; Wang, Xuan; Sei, Kazunari; Ike, Michihiko

2013-04-01

Although 4-tert-butylphenol (4-t-BP) is a serious aquatic pollutant, its biodegradation in aquatic environments has not been well documented. In this study, 4-t-BP was obviously and repeatedly removed from water from four different environments in the presence of Spirodela polyrrhiza, giant duckweed, but 4-t-BP persisted in the environmental waters in the absence of S. polyrrhiza. Also, 4-t-BP was not removed from autoclaved pond water with sterilized S. polyrrhiza. These results suggest that the 4-t-BP removal from the environmental waters was caused by biodegradation stimulated by the presence of S. polyrrhiza rather than by uptake by the plant. Moreover, Sphingobium fuliginis OMI capable of utilizing 4-t-BP as a sole carbon and energy source was isolated from the S. polyrrhiza rhizosphere. Strain OMI degraded 4-t-BP via a meta-cleavage pathway, and also degraded a broad range of alkylphenols with linear or branched alkyl side chains containing two to nine carbon atoms. Root exudates of S. polyrrhiza stimulated 4-t-BP degradation and cell growth of strain OMI. Thus, the stimulating effects of S. polyrrhiza root exudates on 4-t-BP-degrading bacteria might have contributed to 4-t-BP removal in the environmental waters with S. polyrrhiza. These results demonstrate that the S. polyrrhiza-bacteria association may be applicable to the removal of highly persistent 4-t-BP from wastewaters or polluted aquatic environments.

Biodegradability and ecotoxicitiy of tramadol, ranitidine, and their photoderivatives in the aquatic environment.

PubMed

Bergheim, Marlies; Gieré, Reto; Kümmerer, Klaus

2012-01-01

This study was designed to assess the fate and the overall potential impacts of the widely prescribed drugs ranitidine and tramadol after their introduction into the aquatic environment. The probability to detect these two drugs in the aquatic environment was studied by analyzing their abiotic and biotic degradation properties. For this purpose, samples were irradiated with different light sources, and three widely used biodegradability tests from the OECD series, the closed bottle test (OECD 301 D), the manometric respirometry test (OECD 301 F) and the Zahn-Wellens test (OECD 302 B), were conducted. The ecotoxicity of the photolytically formed transformation products was assessed by performing the bacterial growth inhibition test (EN ISO 10712). Furthermore, quantitative structure-activity relationship analysis and a risk analysis based on the calculation of the predicted environmental concentrations have also been conducted to assess the environmental risk potential of the transformation products. The possible formation of stable products by microbial or photolytical transformation has been investigated with DOC and LC-MS analytics. In the present study, neither ranitidine, nor tramadol, nor their photoderivatives were found to be readily or inherently biodegradable according to test guidelines. The photolytic transformation was faster under a UV lamp compared to the reaction under an Xe lamp with a spectrum that mimics sunlight. No chronic toxicity against bacteria was found for ranitidine or its photolytic decomposition products, but a low toxicity was detected for the resulting mixture of the photolytic transformation products of tramadol. The study demonstrates that transformation products may have a higher environmental risk potential than the respective parent compounds.

Soil Column Evaluation of Factors Controlling Biodegradation of DNT in the Vadose Zone

DTIC Science & Technology

2003-01-01

Environ. Sci. Technol. 2003, 37, 3382-3391 3382 9 ENVIRONMENTAL SCIENCE & TECHNOLOGY / VOL. 37, NO. 15, 2003 10.1021/es021066s CCC: $25.00  2003 American...American Society of Agronomy: Madison, WI, 1986; pp 363-375. c EPA 600/2-78-054. VOL. 37, NO. 15, 2003 / ENVIRONMENTAL SCIENCE & TECHNOLOGY 9 3383...initial concentration of 2,4-DNT was 5 mM 3384 9 ENVIRONMENTAL SCIENCE & TECHNOLOGY / VOL. 37, NO. 15, 2003 To ensure accurate quantification of

Biobased, environmentally friendly lubricants for processing plants

USDA-ARS?s Scientific Manuscript database

Vegetable oil based lubricants have excellent lubricity, biodegradability, good viscosity temperature characteristics and low evaporation loss, but poor thermos-oxidative stability and cold flow properties. This paper presents a systematic approach to improve the oxidative and cold flow behavior of...

Protein-based composites and biomaterials

USDA-ARS?s Scientific Manuscript database

World industrialization has generated substantial quantities of petroleum-based plastics over many years, which are not biodegradable or compostable, and are permanently residing on land, in landfills, or in the oceans, as environmental pollution. Recently, total or partially degradable materials ha...

Stereochemistry Considerations Can Improve Pesticide Safety and Sustainability

EPA Science Inventory

About 30% of pesticides are chiral molecules and therefore exist as two or more stereoisomers, which can differ significantly in their toxicity, biodegradation, and persistence. Such differences determine their relative safety to humans and environmental species. Enantiomers, mir...

Evaluation of the BioVapor Model

EPA Science Inventory

The BioVapor model addresses transport and biodegradation of petroleum vapors in the subsurface. This presentation describes basic background on the nature and scientific basis of environmental transport models. It then describes a series of parameter uncertainty runs of the Bi...

How Stereochemistry Considerations can Improve Pesticide Safety

EPA Science Inventory

About 30% of pesticides are chiral molecules and therefore exist as two or more stereoisomers, which can differ significantly in their toxicity, biodegradation, and persistence. Such differences can impact their relative safety to humans and environmental species. Enantiomers, mi...

Biobased Lubricant Development - Problems and Opportunities

USDA-ARS?s Scientific Manuscript database

Biobased lubricants are those comprising ingredients derived from natural sources such as those harvested from farms, forests, etc. Biolubricants provide a number of economic, environmental and health benefits over petroleum-based products. Among these are: biodegradability, renewability and non-t...

GUIDE FOR CONDUCTING TREATABILITY STUDIES UNDER CERCLA: AEROBIC BIODEGRADATION REMEDY SCREENING

EPA Science Inventory

Systematically conducted, well-documented treatability studies are an important component of the remedial investigation/feasibility study (KU FS) process and the remedial design/remedial action (RD/RA) process under the Comprehensive Environmental Response, Compensation, and L...

Life cycle of petroleum biodegradation metabolite plumes, and implications for risk management at fuel release sites.

PubMed

Zemo, Dawn A; O'Reilly, Kirk T; Mohler, Rachel E; Magaw, Renae I; Espino Devine, Catalina; Ahn, Sungwoo; Tiwary, Asheesh K

2017-07-01

This paper summarizes the results of a 5-y research study of the nature and toxicity of petroleum biodegradation metabolites in groundwater at fuel release sites that are quantified as diesel-range "Total Petroleum Hydrocarbons" (TPH; also known as TPHd, diesel-range organics (DRO), etc.), unless a silica gel cleanup (SGC) step is used on the sample extract prior to the TPH analysis. This issue is important for site risk management in regulatory jurisdictions that use TPH as a metric; the presence of these metabolites may preclude site closure even if all other factors can be considered "low-risk." Previous work has shown that up to 100% of the extractable organics in groundwater at petroleum release sites can be biodegradation metabolites. The metabolites can be separated from the hydrocarbons by incorporating an SGC step; however, regulatory agency acceptance of SGC has been inconsistent because of questions about the nature and toxicity of the metabolites. The present study was conducted to answer these specific questions. Groundwater samples collected from source and downgradient wells at fuel release sites were extracted and subjected to targeted gas chromatography-mass spectrometry (GC-MS) and nontargeted two-dimensional gas chromatography with time-of-flight mass spectrometry (GC×GC-MS) analyses, and the metabolites identified in each sample were classified according to molecular structural classes and assigned an oral reference dose (RfD)-based toxicity ranking. Our work demonstrates that the metabolites identified in groundwater at biodegrading fuel release sites are in classes ranked as low toxicity to humans and are not expected to pose significant risk to human health. The identified metabolites naturally attenuate in a predictable manner, with an overall trend to an increasingly higher proportion of organic acids and esters, and a lower human toxicity profile, and a life cycle that is consistent with the low-risk natural attenuation paradigm adopted by many regulatory agencies for petroleum release sites. Integr Environ Assess Manag 2017;13:714-727. © 2016 The Authors. Integrated Environmental Assessment and Management Published by Wiley Periodicals, Inc. on behalf of Society of Environmental Toxicology & Chemistry (SETAC). © 2016 The Authors. Integrated Environmental Assessment and Management Published by Wiley Periodicals, Inc. on behalf of Society of Environmental Toxicology & Chemistry (SETAC).

Predicting ready biodegradability of premanufacture notice chemicals.

PubMed

Boethling, Robert S; Lynch, David G; Thom, Gary C

2003-04-01

Chemical substances other than pesticides, drugs, and food additives are regulated by the U.S. Environmental Protection Agency (U.S. EPA) under the Toxic Substances Control Act (TSCA), but the United States does not require that new substances be tested automatically for such critical properties as biodegradability. The resulting lack of submitted data has fostered the development of estimation methods, and the BioWIN models for predicting biodegradability from chemical structure have played a prominent role in premanufacture notice (PMN) review. Until now, validation efforts have used only the Japanese Ministry of International Trade and Industry (MITI) test data and have not included all models. To assess BioWIN performance with PMN substances, we assembled a database of PMNs for which ready biodegradation data had been submitted over the period 1995 through 2001. The 305 PMN structures are highly varied and pose major challenges to chemical property estimation. Despite the variability of ready biodegradation tests, the use of at least six different test methods, and widely varying quality of submitted data, accuracy of four of six BioWIN models (MITI linear, MITI nonlinear, survey ultimate, survey primary) was in the 80+% range for predicting ready biodegradability. Greater accuracy (>90%) can be achieved by using model estimates only when the four models agree (true for 3/4 of the PMNs). The BioWIN linear and nonlinear probability models did not perform as well even when classification criteria were optimized. The results suggest that the MITI and survey BioWIN models are suitable for use in screening-level applications.

Extracellular degradation of tetrabromobisphenol A via biogenic reactive oxygen species by a marine Pseudoalteromonas sp.

PubMed

Gu, Chen; Wang, Jing; Guo, Mengfan; Sui, Meng; Lu, Hong; Liu, Guangfei

2018-06-07

Tetrabromobisphenol A (TBBPA) has attracted considerable attention due to its ubiquitous presence in different environmental compartments worldwide. However, information on its aerobic biodegradability in coastal environments remains unknown. Here, the aerobic biodegradation of TBBPA using a Pseudoalteromonas species commonly found in the marine environment was investigated. We found that extracellular biogenic siderophore, superoxide anion radical (O 2 •- ), hydrogen peroxide (H 2 O 2 ), and hydroxyl radical ( • OH) were involved in TBBPA degradation. Upregulation of genes (nqrA and lodA) encoding Na + -translocating NADH-quinone oxidoreductase and l-lysine-ε-oxidase supported the extracellular O 2 •- and H 2 O 2 production. The underlying mechanism of TBBPA biodegradation presumably involves both O 2 •- reduction and • OH-based advanced oxidation process (AOP). Furthermore, TBBPA intermediates of tribromobisphenol A, 4-isopropylene-2,6-dibromophenol, 4-(2-hydroxyisopropyl)-2,6-dibromophenol, 2,4,6-tribromophenol (TBP), 4-hydroxybenzoic acid, and 2-bromobenzoic acid were detected in the culture medium. Debromination and β-scission pathways of TBBPA biodegradation were proposed. Additionally, membrane integrity assays revealed that the increase of intracellular catalase (CAT) activity and the extracellular polymeric substances (EPS) might account for the alleviation of oxidative damage. These findings could deepen understanding of the biodegradation mechanism of TBBPA and other related organic pollutants in coastal and artificial bioremediation systems. Copyright © 2018 Elsevier Ltd. All rights reserved.

Acute aquatic toxicity and biodegradation potential of biodiesel fuels

DOE Office of Scientific and Technical Information (OSTI.GOV)

Haws, R.A.; Zhang, X.; Marshall, E.A.

1995-12-31

Recent studies on the biodegradation potential and aquatic toxicity of biodiesel fuels are reviewed. Biodegradation data were obtained using the shaker flask method observing the appearance of CO{sub 2} and by observing the disappearance of test substance with gas chromatography. Additional BOD{sub 5} and COD data were obtained. The results indicate the ready biodegradability of biodiesel fuels as well as the enhanced co-metabolic biodegradation of biodiesel and petroleum diesel fuel mixtures. The study examined reference diesel, neat soy oil, neat rape oil, and the methyl and ethyl esters of these vegetable oils as well as various fuel blends. Acute toxicitymore » tests on biodiesel fuels and blends were performed using Oncorhynchus mykiss (Rainbow Trout) in a static non-renewal system and in a proportional dilution flow replacement system. The study is intended to develop data on the acute aquatic toxicity of biodiesel fuels and blends under US EPA Good Laboratory Practice Standards. The test procedure is designed from the guidelines outlined in Methods for Measuring the Acute Toxicity of Effluents and Receiving Waters to Freshwater and Marine Organisms and the Fish Acute Aquatic Toxicity Test guideline used to develop aquatic toxicity data for substances subject to environmental effects test regulations under TSCA. The acute aquatic toxicity is estimated by an LC50, a lethal concentration effecting mortality in 50% of the test population.« less

The Environmental Behavior of Methylene-4,4'-dianiline.

PubMed

Schupp, Thomas; Allmendinger, Hans; Boegi, Christian; Bossuyt, Bart T A; Hidding, Bjoern; Shen, Summer; Tury, Bernard; West, Robert J

2018-06-24

Methylene-4,4'-dianiline (MDA, CAS-No. 101-77-9) is a high production volume intermediate that is mainly processed to diisocyanates and finally polyurethanes. This review summarizes available data concerning the environmental behavior. When released into the environment, MDA distributes into water and subsequently sediment and soil compartments; the air is of little relevance, owed to the low vapor pressure and short atmospheric half-life, which renders MDA non-critical for long-range transport. Biodegradation data present a diverged picture; in some tests, MDA is not readily biodegradable or even not inherent biodegradable; in other tests, MDA turned out to be readily biodegradable (but failing the 10-d window). The history and composition of the inoculum used for testing seem to play an important role, which is underlined by good test results with adapted inoculum. In soil, initially a rapid mineralization is observed, which slows down within the first days due to competitive chemical absorption. The latter results in degradation rates comparable to that of natural organic matter. Under anaerobic conditions, mineralization is poor. Irreversible chemisorption occurs unless soils/sediments are highly reduced. Half-lives due to primary decay do not indicate MDA to be persistent according to the regulatory guidance used in then EU, Canada, or the USA; in Japan, however, due to test results in MITI degradation tests, MDA would be regarded as persistent. The identification of microbial MDA metabolites deserves further research. MDA is not bioaccumulative, but it is toxic to aquatic organisms and mammals. MDA in pore water of soils is rapidly adsorbed on the surface of plant roots. Test runs were too short to draw a final conclusion with regards to transport to stem, leaves, and fruits. Data from structurally similar compounds indicate that such transport would account for less than 1% of the root-adsorbed material.

Comprehensive GC²/MS for the monitoring of aromatic tar oil constituents during biodegradation in a historically contaminated soil.

PubMed

Vasilieva, Viktoriya; Scherr, Kerstin E; Edelmann, Eva; Hasinger, Marion; Loibner, Andreas P

2012-02-20

The constituents of tar oil comprise a wide range of physico-chemically heterogeneous pollutants of environmental concern. Besides the sixteen polycyclic aromatic hydrocarbons defined as priority pollutants by the US-EPA (EPA-PAHs), a wide range of substituted (NSO-PAC) and alkylated (alkyl-PAC) aromatic tar oil compounds are gaining increased attention for their toxic, carcinogenic, mutagenic and/or teratogenic properties. Investigations on tar oil biodegradation in soil are in part hampered by the absence of an efficient analytical tool for the simultaneous analysis of this wide range of compounds with dissimilar analytical properties. Therefore, the present study sets out to explore the applicability of comprehensive two-dimensional gas chromatography (GC²/MS) for the simultaneous measurement of compounds with differing polarity or that are co-eluting in one-dimensional systems. Aerobic tar oil biodegradation in a historically contaminated soil was analyzed over 56 days in lab-scale bioslurry tests. Forty-three aromatic compounds were identified with GC²/MS in one single analysis. The number of alkyl chains on a molecule was found to prime over alkyl chain length in hampering compound biodegradation. In most cases, substitution of carbon with nitrogen and oxygen was related to increased compound degradation in comparison to unalkylated and sulphur- or unsubstituted PAH with a similar ring number.The obtained results indicate that GC²/MS can be employed for the rapid assessment of a large variety of structurally heterogeneous environmental contaminants. Its application can contribute to facilitate site assessment, development and control of microbial cleanup technologies for tar oil contaminated sites. Copyright © 2011 Elsevier B.V. All rights reserved.

Screening of Bacillus strains isolated from mangrove ecosystems in Peninsular Malaysia for microplastic degradation.

PubMed

Auta, H S; Emenike, C U; Fauziah, S H

2017-12-01

The continuous accumulation of microplastics in the environment poses ecological threats and has been an increasing problem worldwide. In this study, eight bacterial strains were isolated from mangrove sediment in Peninsular Malaysia to mitigate the environmental impact of microplastics and develop a clean-up option. The bacterial isolates were screened for their potential to degrade UV-treated microplastics from polyethylene (PE), polyethylene terephthalate (PET), polypropylene (PP), and polystyrene (PS). Only two isolates, namely, Bacillus cereus and Bacillus gottheilii, grew on a synthetic medium containing different microplastic polymers as the sole carbon source. A shake flask experiment was carried out to further evaluate the biodegradability potential of the isolates. Degradation was monitored by recording the weight loss of microplastics and the growth pattern of the isolates in the mineral medium. The biodegradation extent was validated by assessment of the morphological and structural changes through scanning electron microscopy and Fourier transform infrared spectroscopy analyses. The calculated weight loss percentages of the microplastic particles by B. cereus after 40 days were 1.6%, 6.6%, and 7.4% for PE, PET, and PS, respectively. B. gottheilii recorded weight loss percentages of 6.2%, 3.0%, 3.6%, and 5.8% for PE, PET, PP, and PS, respectively. The designated isolates degraded the microplastic material and exhibited potential for remediation of microplastic-contaminated environment. Biodegradation tests must be conducted to characterize the varied responses of microbes toward pollutants, such as microplastics. Hence, a novel approach for biodegradation of microplastics must be developed to help mitigate the environmental impact of plastics and microplastic polymers. Copyright © 2017 Elsevier Ltd. All rights reserved.

Soil bacterial consortia and previous exposure enhance the biodegradation of sulfonamides from pig manure.

PubMed

Islas-Espinoza, Marina; Reid, Brian J; Wexler, Margaret; Bond, Philip L

2012-07-01

Persistence or degradation of synthetic antibiotics in soil is crucial in assessing their environmental risks. Microbial catabolic activity in a sandy loamy soil with pig manure using 12C- and 14C-labelled sulfamethazine (SMZ) respirometry showed that SMZ was not readily degradable. But after 100 days, degradation in sulfadiazine-exposed manure was 9.2%, far greater than soil and organic manure (0.5% and 0.11%, respectively, p < 0.05). Abiotic degradation was not detected suggesting microbial catabolism as main degradation mechanism. Terminal restriction fragment length polymorphism showed biodiversity increases within 1 day of SMZ spiking and especially after 200 days, although some species plummeted. A clone library from the treatment with highest degradation showed that most bacteria belonged to α, β and γ classes of Proteobacteria, Firmicutes, Bacteroidetes and Acidobacteria. Proteobacteria (α, β and γ), Firmicutes and Bacteroidetes which were the most abundant classes on day 1 also decreased most following prolonged exposure. From the matrix showing the highest degradation rate, 17 SMZ-resistant isolates biodegraded low levels of 14C-labelled SMZ when each species was incubated separately (0.2-1.5%) but biodegradation was enhanced when the four isolates with the highest biodegradation were incubated in a consortium (Bacillus licheniformis, Pseudomonas putida, Alcaligenes sp. and Aquamicrobium defluvium as per 16S rRNA gene sequencing), removing up to 7.8% of SMZ after 20 days. One of these species (B. licheniformis) was a known livestock and occasional human pathogen. Despite an environmental role of these species in sulfonamide bioremediation, the possibility of horizontal transfer of pathogenicity and resistance genes should caution against an indiscriminate use of these species as sulfonamide degraders.

Whose butt is it? tobacco industry research about smokers and cigarette butt waste.

PubMed

Smith, Elizabeth A; Novotny, Thomas E

2011-05-01

Cigarette filters are made of non-biodegradable cellulose acetate. As much as 766,571 metric tons of butts wind up as litter worldwide per year. Numerous proposals have been made to prevent or mitigate cigarette butt pollution, but none has been effective; cigarette butts are consistently found to be the single most collected item in beach clean-ups and litter surveys. We searched the Legacy Tobacco Documents Library (http://legacy.library.ucsf.edu) and http://tobaccodocuments.org using a snowball strategy beginning with keywords (eg, 'filter', 'biodegradable', 'butts'). Data from approximately 680 documents, dated 1959-2006, were analysed using an interpretive approach. The tobacco industry has feared being held responsible for cigarette litter for more than 20 years. Their efforts to avoid this responsibility included developing biodegradable filters, creating anti-litter campaigns, and distributing portable and permanent ashtrays. They concluded that biodegradable filters would probably encourage littering and would not be marketable, and that smokers were defensive about discarding their tobacco butts and not amenable to anti-litter efforts. Tobacco control and environmental advocates should develop partnerships to compel the industry to take financial and practical responsibility for cigarette butt waste.

Aerobic biodegradation potential of endocrine disrupting chemicals in surface-water sediment at Rocky Mountains National Park, USA

USGS Publications Warehouse

Bradley, Paul M.; Battaglin, William A.; Iwanowicz, Luke R.; Clark, Jimmy M.; Journey, Celeste A.

2016-01-01

Endocrine disrupting chemicals (EDC) in surface water and bed sediment threaten the structure and function of aquatic ecosystems. In natural, remote, and protected surface-water environments where contaminant releases are sporadic, contaminant biodegradation is a fundamental driver of exposure concentration, timing, duration, and, thus, EDC ecological risk. Anthropogenic contaminants, including known and suspected EDC, were detected in surface water and sediment collected from 2 streams and 2 lakes in Rocky Mountains National Park (ROMO). The potential for aerobic EDC biodegradation was assessed in collected sediments using 6 14C-radiolabeled model compounds. Aerobic microbial mineralization of natural (estrone and 17β-estradiol) and synthetic (17α-ethinylestradiol) estrogen was significant at all sites. ROMO bed sediment microbial communities also effectively degraded the xenoestrogens, bisphenol-A and 4-nonylphenol. The same sediment samples exhibited little potential for aerobic biodegradation of triclocarban, however, illustrating the need to assess a wider range of contaminant compounds. The current results support recent concerns over the widespread environmental occurrence of carbanalide antibacterials, like triclocarban and triclosan, and suggest that backcountry use of products containing these compounds should be discouraged.

Blends of low molecular weight of poly lactic acid (PLA) with gondorukem (gum rosin)

NASA Astrophysics Data System (ADS)

Kaavessina, Mujtahid; Distantina, Sperisa; Chafidz, Achmad; Utama, Aditya; Anggraeni, Venisa Mega Puteri

2018-02-01

The utilization of plastic was increasing as well as the increasing its demand in wide range application. Consequently, the number of plastic litter will increase and make more serious environmental problems. This research concerns to minimize waste problems by designing biodegradable plastic. In this research, biodegradable plastic was made of poly lactic acid (PLA) and gondorukem (Gum rosin, Resina colophonium) as the plasticizer. The effect of gondorukem towards PLA properties such as rheology and degradability was investigated. The research divided into two steps: (i) the polycondensation of lactic acid (LA) and (ii) modification of obtained poly lactic acid. In the first step, polycondensation was done in N2 atmosphere (138°C) for 30 hours and added 0.1 %w of SnCl2 as catalyst. Bulk modification was conducted by blending of gondurukem in varied weight (0.5, 1, and 2 g in 10 g of PLA). Furthermore, the modified PLA was analyzed its molecular structure, biodegradability and rheological property. The presence of gondorukem enhanced the biodegradability of poly lactic acid. Gondorukem could act as the plasticizer. It is confirmed that the complex viscosity of PLA melt decreased upon the addition of gondorukem

Evaluation of Toxicity and Biodegradability of Cholinium Amino Acids Ionic Liquids

PubMed Central

Hou, Xue-Dan; Liu, Qiu-Ping; Smith, Thomas J.; Li, Ning; Zong, Min-Hua

2013-01-01

Cholinium amino acid ionic liquids ([Ch][AA] ILs), which are wholly composed of renewable biomaterials, have recently been demonstrated to have very promising properties for applications in organic synthesis and biomass pretreatment. In this work, the toxicity of these ILs toward enzymes and bacteria was assessed, and the effect of the anion on these properties is discussed. The inhibitory potentials of this type of ILs to acetylcholinesterase were weaker approximately an order of magnitude than the traditional IL 1-butyl-3-methylimidazolium tetrafluoroborate. Additionally, the [Ch][AA] ILs displayed low toxicity toward the bacteria tested. Furthermore, the biodegradability of the [Ch][AA] ILs was evaluated via the closed bottle and CO2 headspace tests using wastewater microorganisms. All the ILs were classified as ‘readily biodegradable’ based on their high levels of mineralization (62-87%). The presence of extra carboxyl or amide groups on the amino acid side chain rendered the ILs significantly more susceptible to microbial breakdown. In addition, for most of the [Ch][AA] ILs, low toxicity correlated with good biodegradability. The low toxicity and high biodegradability of these novel [Ch][AA] make them promising candidates for use as environmentally friendly solvents in large-scale applications. PMID:23554985

PHOTOCROSSLINKED IMMOBILIZATION OF POLYELECTROLYTES FOR TEMPLATE ASSISTED ENZYMATIC POLYMERIZATION OF CONJUGATED POLYMERS

EPA Science Inventory

Growing demand in consumer electronics raises need for efficient, affordable, environmentally benign and biodegradable substitutes for current technologies. Printed circuit boards contain heavy metals such as antimony, silver, chromium, zinc, lead, tin and copper. According t...

Skatole biodegradation via isolates from swine manure

USDA-ARS?s Scientific Manuscript database

Animal waste disposal and odor control have become a major issue for animal production facilities. As an attempt to improve efficiency and profit margins, many livestock operations have become large concentrated rearing facilities. As a result, many concerns over potentially adverse environmental ...

BioVapor Model Evaluation (St. Louis, MO)

EPA Science Inventory

The BioVapor model addresses transport and biodegradation of petroleum vapors in the subsurface. This presentation describes basic background on the nature and scientific basis of environmental transport models. It then describes a series of parameter uncertainty runs of the Bi...

KINETIC MODEL OF BIOSURFACTANT ENHANCED HEXADECANE BIODEGRADATION BY PSEUDOMONAS AERUGINOSA. (R827132)

EPA Science Inventory

Many sites of environmental concern contain groundwater contaminated with nonaqueous phase liquids (NAPL). In such sites interfacial processes may affect both the equilibrium and kinetic behavior of the system. In particular, insoluble hydrocarbon partitioning and microbial biode...

Ecodesign of cosmetic formulae: methodology and application.

PubMed

L'Haridon, J; Martz, P; Chenéble, J-C; Campion, J-F; Colombe, L

2018-04-01

This article describes an easy-to-use ecodesign methodology developed and applied since 2014 by the L'Oréal Group to improve the sustainable performance of its new products without any compromise on their cosmetic efficacy. Cosmetic products, after being used, are often discharged into the sewers and the aquatic compartment. This discharge is considered as dispersive and continuous. A consistent progress in reducing the environmental impact of cosmetic products can be achieved through focusing upon three strategic indicators: biodegradability, grey water footprint adapted for ecodesign (GWFE) and a global indicator, complementary to these two endpoints. Biodegradability represents the key process in the removal of organic ingredients from the environment. GWFE is defined herein as the theoretical volume of natural freshwater required to dilute a cosmetic formula after being used by the consumer, down to a concentration without any foreseeable toxic effects upon aquatic species. Finally, the complementary indicator highlights a possible alert on formula ingredients due to an unfavourable environmental profile based on hazard properties: for example Global Harmonization System/Classification, Labelling and Packaging (GHS/CLP) H410 classification or potential very persistent and very bioaccumulative (vPvB) classification. The ecodesign of a new cosmetic product can be a challenge as the cosmetic properties and quality of this new product should at least match the benchmark reference. As shown in the case studies described herein, new methodologies have been developed to maximize the biodegradability of cosmetic formulae, to minimize their GWFE and to limit the use of ingredients that present an unfavourable environmental profile, while reaching the highest standards in terms of cosmetic efficacy. By applying these methodologies, highly biodegradable products (≥ 95% based on ingredient composition) have been developed and marketed, with a low GWFE. This new ecodesign approach shows that embedding sustainability in developing new cosmetic products can also open up new innovative opportunities. © 2018 The Authors. International Journal of Cosmetic Science published by John Wiley & Sons Ltd on behalf of Society of Cosmetic Scientists and the Société Française de Cosmétologie.

DESIGN AND TESTING OF SECOND GENERATION BIOREMEDIATION TECHNOLOGIES FOR CHLORINATED SOLVENT CONTAMINATED SITES

EPA Science Inventory

The contamination of ground water at industrial and military facilities by chlorinated solvents remains a significant environmental challenge. In the 1990's several successful demonstrations of in situ biodegradation processes, targeted for chloroethenes, occurred. While these tr...

CHALLENGES IN BIODEGRADATION OF TRACE ORGANIC CONTAMINANTS-GASOLINE OXYGENATES AND SEX HORMONES

EPA Science Inventory

Advances in analytical methods have led to the identification of several classes of organic chemicals that are associated with adverse environmental impacts. Two such classes of organic chemicals, gasoline oxygenates and sex hormones, are used to illustrate challenges associated ...

DESIGN OF BIODEGRADATION EXPERIMENTS FOR FLUOROTELOMER-BASED POLYMERS

EPA Science Inventory

Fluorotelomer-based polymers (FBPs) are used in a wide variety of consumer products and are widely distributed throughout society. Accordingly, there is great interest in whether and how fast these materials might degrade in various environmental settings. A useful quality of FB...

UV-photodegradation of desipramine: Impact of concentration, pH and temperature on formation of products including their biodegradability and toxicity.

PubMed

Khaleel, Nareman D H; Mahmoud, Waleed M M; Olsson, Oliver; Kümmerer, Klaus

2016-10-01

Desipramine (DMI) is a widely used tricyclic antidepressant, and it is the major metabolite of imipramine (IMI) and lofepramine (LMI); IMI and LMI are two of the most commonly used tricyclic antidepressants. If DMI enters the aquatic environment, it can be transformed by the environmental bacteria or UV radiation. Therefore, photolysis of DMI in water was performed using a simulated sunlight Xenon-lamp and a UV-lamp. Subsequently, the biodegradability of DMI and its photo-transformation products (PTPs) formed during its UV photolysis was studied. The influence of variable conditions, such as initial DMI concentration, solution pH, and temperature, on DMI UV photolysis behavior was also studied. The degree of mineralization of DMI and its PTPs was monitored. A Shimadzu HPLC-UV apparatus was used to follow the kinetic profile of DMI during UV-irradiation; after that, ion-trap and high-resolution mass spectrometry coupled with chromatography were used to monitor and identify the possible PTPs. The environmentally relevant properties and selected toxicity properties of DMI and the non-biodegradable PTPs were predicted using different QSAR models. DMI underwent UV photolysis with first-order kinetics. Quantum yields were very low. DOC values indicated that DMI formed new PTPs and was not completely mineralized. Analysis by means of high-resolution mass spectrometry revealed that the photolysis of DMI followed three main photolysis pathways: isomerization, hydroxylation, and ring opening. The photolysis rate was inversely proportional to initial DMI concentration. The pH showed a significant impact on the photolysis rate of DMI, and on the PTPs in terms of both formation kinetics and mechanisms. Although temperature was expected to increase the photolysis rate, it showed a non-significant impact in this study. Results from biodegradation tests and QSAR analysis revealed that DMI and its PTPs are not readily biodegradable and that some PTPs may be human and/or eco-toxic, so they may pose a risk to the environment. Copyright © 2016 Elsevier B.V. All rights reserved.

A new model for the biodegradation kinetics of oil droplets: application to the Deepwater Horizon oil spill in the Gulf of Mexico

PubMed Central

2013-01-01

Oil biodegradation by native bacteria is one of the most important natural processes that can attenuate the environmental impacts of marine oil spills. Existing models for oil biodegradation kinetics are mostly for dissolved oil. This work developed a new mathematical model for the biodegradation of oil droplets and applied the model to estimate the time scale for oil biodegradation under conditions relevant to the Deepwater Horizon oil spill in the Gulf of Mexico. In the model, oil is composed of droplets of various sizes following the gamma function distribution. Each oil droplet shrinks during the microbe-mediated degradation at the oil-water interface. Using our developed model, we find that the degradation of oil droplets typically goes through two stages. The first stage is characterized by microbial activity unlimited by oil-water interface with higher biodegradation rates than that of the dissolved oil. The second stage is governed by the availability of the oil-water interface, which results in much slower rates than that of soluble oil. As a result, compared to that of the dissolved oil, the degradation of oil droplets typically starts faster and then quickly slows down, ultimately reaching a smaller percentage of degraded oil in longer time. The availability of the water-oil interface plays a key role in determining the rates and extent of degradation. We find that several parameters control biodegradation rates, including size distribution of oil droplets, initial microbial concentrations, initial oil concentration and composition. Under conditions relevant to the Deepwater Horizon spill, we find that the size distribution of oil droplets (mean and coefficient of variance) is the most important parameter because it determines the availability of the oil-water interface. Smaller oil droplets with larger variance leads to faster and larger extent of degradation. The developed model will be useful for evaluating transport and fate of spilled oil, different remediation strategies, and risk assessment. PMID:24138161

Fate and Tranport of MTBE in Clay-Rich Materials

NASA Astrophysics Data System (ADS)

lenczewski, m e

2001-12-01

A recent report by the U.S. Geological Survey identified methyl tert-butyl ether (MTBE), a constituent of reformulated gasoline, as the most common contaminant of urban aquifers in the United States. MTBE has been released into groundwater supplies by leaking underground fuel tanks. In Illinois, it has been found in 26 of the 1,800 public water supplies and although detection was intermittent, levels were high enough to be offensive to users in some Illinois communities. MTBE is also being used in Mexico to solve the problem of air quality; however, it has the potential to harm the drinking water quality in the process. Early research on MTBE considered it resistant to biodegradation and unable to adsorb to soils and sediments. However, recent evidence indicates that biodegradation does occur under certain conditions and that sorption can occur to organic materials. This research project will investigate the biodegradation of MTBE and its sorption to the clay-rich glacial till found in northern Illinois and lacustrine clays found in the Chalco Basin, Mexico City, Mexico whose interaction with MTBE has not previously been studied. The principal hypothesis of this research is that the microorganisms and environmental factors in clay-rich materials will increase the biodegradation and sorption of MTBE as compared to sandy materials. The experiments will simulate a spill of MTBE or downgradient from a gasoline spill. Microcosms and batch isotherm experiments will be used to demonstrate the potential for biodegradation and sorption in these materials; however, laboratory results are not considered reliable estimates of actual field sorption and biodegradation rates. Therefore long-term column experiments will also be conducted in which large sample volumes of material that simulate the heterogeneities naturally observed in the environment. This research will increase understanding of the biodegradation and sorption of MTBE and lay the necessary groundwork to implement the optimal remediation method for sites contaminated by MTBE, helping to ensure a sustainable groundwater resource.

Reflectometric interference spectroscopy-based sensing for evaluating biodegradability of polymeric thin films.

PubMed

Ooya, Tooru; Sakata, Yasuhiko; Choi, Hyung Woo; Takeuchi, Toshifumi

2016-07-01

Enzymatic degradation of poly(ε-caprolactone) (PCL) thin films was analyzed by reflectometric interference spectroscopy (RIfS)-based sensing system, and validated by attenuated total reflection infrared spectroscopy (ATR-IR) imaging. The degradation of the PCL thin film spin-coated on the silicon substrate on which 65-nm silicon nitride layer was deposited as an interference layer was easily monitored by shifting the peak bottom of reflectance spectra (Δλ) that is known to be proportional to the thickness of thin films. The Δλ values decreased with increasing the concentration of lipase from Pseudomonas cepacia, and the obtained sensorgrams were applied for kinetic analysis using a curve fitting software. ATR-IR spectra and imaging analysis on the surface of the PCL film revealed that carbonyl groups on the surface decreased with time, resulting from proceeding with the enzymatic hydrolysis, and importantly, extinction of the carbonyl group was declined with proportional to the decrease in the film thickness measured by the RIfS system. Consequently, the present RIfS-based label-free monitoring system can provide a simple and reliable way for evaluating biodegradability on synthetic materials. A RIfS-based sensing system in combination with ATR-IR measurements can be an analytical method for evaluation of biodegradability of polymeric thin films. This study demonstrates the utility of the RIfS-based sensing approach for analyzing the lipase-catalyzed degradation of PCL. Despite the RIfS is known as an inexpensive label-free detection method for biological interaction, the RIfS applications as monitoring methods for enzymatic degradation of biodegradable polymers had not been systematically explored. This study additionally demonstrated the capability of combined analysis of the biodegradation with ATR-IR spectra/imaging and RIfS measurements, which could be broadly applied towards evaluating biodegradability of various biodegradable polymers in environmental protection research. Copyright © 2016 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.

Biodegradation of 17β-Estradiol, Estrone and Testosterone in Stream Sediments

NASA Astrophysics Data System (ADS)

Bradley, P. M.; Chapelle, F. H.; Barber, L. B.; McMahon, P. B.; Gray, J. L.; Kolpin, D. W.

2009-12-01

The potentials for in situ biodegradation of 17β-estradiol (E2), estrone (E1), and testosterone (T) were investigated in three, hydrologically-distinct, WWTP-impacted streams in the United States. Relative differences in the mineralization of [4-14C] substrates were assessed in oxic microcosms containing sediment or water-only from locations upstream and downstream of the WWTP outfall in each system. Upstream samples provided insight into the biodegradative potential of sediment microbial communities that were not under the immediate impact of WWTP effluent. Upstream sediment from all three systems demonstrated significant mineralization of the “A” ring of E2, E1 and T, with the potential of T biodegradation consistently greater than of E2 and no systematic difference in the potentials of E2 and E1. Downstream samples provided insight into the impacts of effluent on reproductive hormone biodegradation. Significant “A” ring mineralization was also observed in downstream sediment, with the potentials for E1 and T mineralization being substantially depressed relative to upstream samples. In marked contrast, the potentials for E2 mineralization immediately downstream of the WWTP outfalls were more than double that of upstream samples. E2 mineralization was also observed in water, albeit at insufficient rate to prevent substantial downstream transport in the water column. The results of this study indicate that, in combination with sediment sorption processes which effectively scavenge hydrophobic contaminants from the water column and immobilize them in the vicinity of the WWTP outfall, aerobic biodegradation of reproductive hormones can be an environmentally important mechanism for non-conservative (destructive) attenuation of hormonal endocrine disruptors in effluent-impacted streams.

High barrier multilayer packaging by the coextrusion method: The effect of nanocomposites and biodegradable polymers on flexible film properties

NASA Astrophysics Data System (ADS)

Thellen, Christopher T.

The objective of this research was to investigate the use of nanocomposite and multilayer co-extrusion technologies for the development of high gas barrier packaging that is more environmentally friendly than many current packaging system. Co-extruded bio-based and biodegradable polymers that could be composted in a municipal landfill were one direction that this research was aimed. Down-gauging of high performance barrier films using nanocomposite technology and co-extrusion was also investigated in order to reduce the amount of solid waste being generated by the packaging. Although the research is focused on military ration packaging, the technologies could easily be introduced into the commercial flexible packaging market. Multilayer packaging consisting of poly(m-xylylene adipamide) nanocomposite layers along with adhesive and tie layers was co-extruded using both laboratory and pilot-scale film extrusion equipment. Co-extrusion of biodegradable polyhydroxyalkanoates (PHA) along with polyvinyl alcohol (PVOH) and tie layers was also accomplished using similar co-extrusion technology. All multilayer films were characterized for gas barrier, mechanical, and thermal properties. The biodegradability of the PVOH and PHA materials in a marine environment was also investigated. The research has shown that co-extrusion of these materials is possible at a research and pilot level. The use of nanocomposite poly(m-xylylene adipamide) was effective in down-gauging the un-filled barrier film to thinner structures. Bio-based PHA/PVOH films required the use of a malefic anhydride grafted PHA tie layer to improve layer to layer adhesion in the structure to avoid delamination. The PHA polymer demonstrated a high rate of biodegradability/mineralization in the marine environment while the rate of biodegradation of the PVOH polymer was slower.

Degradability enhancement of poly(lactic acid) by stearate-Zn(3)Al LDH nanolayers.

PubMed

Eili, Mahboobeh; Shameli, Kamyar; Ibrahim, Nor Azowa; Yunus, Wan Md Zin Wan

2012-01-01

Recent environmental problems and societal concerns associated with the disposal of petroleum based plastics throughout the world have triggered renewed efforts to develop new biodegradable products compatible with our environment. This article describes the preparation, characterization and biodegradation study of poly(lactic acid)/layered double hydroxide (PLA/LDH) nanocomposites from PLA and stearate-Zn(3)Al LDH. A solution casting method was used to prepare PLA/stearate-Zn(3)Al LDH nanocomposites. The anionic clay Zn(3)Al LDH was firstly prepared by co-precipitation method from a nitrate salt solution at pH 7.0 and then modified by stearate anions through an ion exchange reaction. This modification increased the basal spacing of the synthetic clay from 8.83 Å to 40.10 Å. The morphology and properties of the prepared PLA/stearate-Zn(3)Al LDH nanocomposites were studied by X-ray diffraction (XRD), transmission electron microscope (TEM), scanning electron microscope (SEM), thermogravimetric analysis (TGA), tensile tests as well as biodegradation studies. From the XRD analysis and TEM observation, the stearate-Zn(3)Al LDH lost its ordered stacking-structure and was greatly exfoliated in the PLA matrix. Tensile test results of PLA/stearate-Zn(3)Al LDH nanocomposites showed that the presence of around 1.0-3.0 wt % of the stearate-Zn(3)Al LDH in the PLA drastically improved its elongation at break. The biodegradation studies demonstrated a significant biodegradation rate improvement of PLA in the presence of stearate-Zn(3)Al LDH nanolayers. This effect can be caused by the catalytic role of the stearate groups in the biodegradation mechanism leading to much faster disintegration of nanocomposites than pure PLA.

Behaviour of five pharmaceuticals with high baseline toxicity in wastewater treatment

NASA Astrophysics Data System (ADS)

van Driezum, Inge; McArdell, Christa; Fenner, Kathrin; Helbling, Damian; van Breukelen, Boris

2013-04-01

Many pharmaceuticals enter the aquatic environment through sewer systems and are partially removed in wastewater treatment plants (WWTP) by sorption to sludge biomass or biodegradation. Biodegradation often does not lead to complete mineralization but to the formation of stable transformation products (TPs), which might still be harmful to the environment. Recently, a study was undertaken to assess the risk of the top 100 pharmaceuticals from wastewater of a hospital in Switzerland. The predicted toxicity was linked to the predicted environmental concentration in order to assess overall risk potential. In this study, biodegradation and sorption studies were carried out on the top five selected pharmaceuticals (amiodarone, atorvastatin, clotrimazole, meclozine and ritonavir). Potential TPs that are formed during activated sludge treatment were identified and concentrations of both the parent compounds and TPs were measured in the WWTP. With this data, the fate of these compounds was modeled in a WWTP system using a multi-reactor steady-state WWTP model. This study showed that sorption was the most important loss process for amiodarone and meclozine. They had an elimination of more than 99%. Sorption was also the main loss process for clotrimazole, but it was combined with some biodegradation. For ritonavir, both biodegradation and sorption played a role in the loss of this compound. The most important removal process for atorvastatin was biodegradation. Four TPs, formed through β-oxidation and monohydroxilation, were identified in both the activated sludge batch reactors and the WWTP effluent. In the WWTP effluent, only atorvastatin, clotrimazole and ritonavir were found. All identified TPs of atorvastatin were detected in the effluent. Risk quotients (RQ) of all five pharmaceuticals were estimated based on effluent concentration and baseline toxicity and ranged from zero to 2.14. Only ritonavir potentially poses an ecotoxicological risk for the aquatic environment.

Kinetics and yields of pesticide biodegradation at low substrate concentrations and under conditions restricting assimilable organic carbon.

PubMed

Helbling, Damian E; Hammes, Frederik; Egli, Thomas; Kohler, Hans-Peter E

2014-02-01

The fundamentals of growth-linked biodegradation occurring at low substrate concentrations are poorly understood. Substrate utilization kinetics and microbial growth yields are two critically important process parameters that can be influenced by low substrate concentrations. Standard biodegradation tests aimed at measuring these parameters generally ignore the ubiquitous occurrence of assimilable organic carbon (AOC) in experimental systems which can be present at concentrations exceeding the concentration of the target substrate. The occurrence of AOC effectively makes biodegradation assays conducted at low substrate concentrations mixed-substrate assays, which can have profound effects on observed substrate utilization kinetics and microbial growth yields. In this work, we introduce a novel methodology for investigating biodegradation at low concentrations by restricting AOC in our experiments. We modified an existing method designed to measure trace concentrations of AOC in water samples and applied it to systems in which pure bacterial strains were growing on pesticide substrates between 0.01 and 50 mg liter(-1). We simultaneously measured substrate concentrations by means of high-performance liquid chromatography with UV detection (HPLC-UV) or mass spectrometry (MS) and cell densities by means of flow cytometry. Our data demonstrate that substrate utilization kinetic parameters estimated from high-concentration experiments can be used to predict substrate utilization at low concentrations under AOC-restricted conditions. Further, restricting AOC in our experiments enabled accurate and direct measurement of microbial growth yields at environmentally relevant concentrations for the first time. These are critical measurements for evaluating the degradation potential of natural or engineered remediation systems. Our work provides novel insights into the kinetics of biodegradation processes and growth yields at low substrate concentrations.

Degradability Enhancement of Poly(Lactic Acid) by Stearate-Zn3Al LDH Nanolayers

PubMed Central

Eili, Mahboobeh; Shameli, Kamyar; Ibrahim, Nor Azowa; Yunus, Wan Md Zin Wan

2012-01-01

Recent environmental problems and societal concerns associated with the disposal of petroleum based plastics throughout the world have triggered renewed efforts to develop new biodegradable products compatible with our environment. This article describes the preparation, characterization and biodegradation study of poly(lactic acid)/layered double hydroxide (PLA/LDH) nanocomposites from PLA and stearate-Zn3Al LDH. A solution casting method was used to prepare PLA/stearate-Zn3Al LDH nanocomposites. The anionic clay Zn3Al LDH was firstly prepared by co-precipitation method from a nitrate salt solution at pH 7.0 and then modified by stearate anions through an ion exchange reaction. This modification increased the basal spacing of the synthetic clay from 8.83 Å to 40.10 Å. The morphology and properties of the prepared PLA/stearate-Zn3Al LDH nanocomposites were studied by X-ray diffraction (XRD), transmission electron microscope (TEM), scanning electron microscope (SEM), thermogravimetric analysis (TGA), tensile tests as well as biodegradation studies. From the XRD analysis and TEM observation, the stearate-Zn3Al LDH lost its ordered stacking-structure and was greatly exfoliated in the PLA matrix. Tensile test results of PLA/stearate-Zn3Al LDH nanocomposites showed that the presence of around 1.0–3.0 wt % of the stearate-Zn3Al LDH in the PLA drastically improved its elongation at break. The biodegradation studies demonstrated a significant biodegradation rate improvement of PLA in the presence of stearate-Zn3Al LDH nanolayers. This effect can be caused by the catalytic role of the stearate groups in the biodegradation mechanism leading to much faster disintegration of nanocomposites than pure PLA. PMID:22942682

Potential of Endophytic Bacterium Paenibacillus sp. PHE-3 Isolated from Plantago asiatica L. for Reduction of PAH Contamination in Plant Tissues

PubMed Central

Zhu, Xuezhu; Jin, Li; Sun, Kai; Li, Shuang; Ling, Wanting; Li, Xuelin

2016-01-01

Endophytes are ubiquitous in plants, and they may have a natural capacity to biodegrade polycyclic aromatic hydrocarbons (PAHs). In our study, a phenanthrene-degrading endophytic Paenibacillus sp. PHE-3 was isolated from P. asiatica L. grown in a PAH-contaminated site. The effects of environmental variables on phenanthrene biodegradation by strain PHE-3 were studied, and the ability of strain PHE-3 to use high molecular weight PAH (HMW-PAH) as a sole carbon source was also evaluated. Our results indicated that pH value of 4.0–8.0, temperature of 30 °C–42 °C, initial phenanthrene concentration less than 100 mg·L−1, and some additional nutrients are favorable for the biodegradation of phenanthrene by strain PHE-3. The maximum biodegradation efficiency of phenanthrene was achieved at 99.9% after 84 h cultivation with additional glutamate. Moreover, the phenanthrene biodegradation by strain PHE-3 was positively correlated with the catechol 2,3-dioxygenase activity (ρ = 0.981, p < 0.05), suggesting that strain PHE-3 had the capability of degrading HMW-PAHs. In the presence of other 2-, 3-ringed PAHs, strain PHE-3 effectively degraded HMW-PAHs through co-metabolism. The results of this study are beneficial in that the re-colonization potential and PAH degradation performance of endophytic Paenibacillus sp. PHE-3 may be applied towards reducing PAH contamination in plants. PMID:27347988

Bacterial diversity characterization in petroleum samples from Brazilian reservoirs

PubMed Central

de Oliveira, Valéria Maia; Sette, Lara Durães; Simioni, Karen Christina Marques; dos Santos Neto, Eugênio Vaz

2008-01-01

This study aimed at evaluating potential differences among the bacterial communities from formation water and oil samples originated from biodegraded and non-biodegraded Brazilian petroleum reservoirs by using a PCR-DGGE based approach. Environmental DNA was isolated and used in PCR reactions with bacterial primers, followed by separation of 16S rDNA fragments in the DGGE. PCR products were also cloned and sequenced, aiming at the taxonomic affiliation of the community members. The fingerprints obtained allowed the direct comparison among the bacterial communities from oil samples presenting distinct degrees of biodegradation, as well as between the communities of formation water and oil sample from the non-biodegraded reservoir. Very similar DGGE band profiles were observed for all samples, and the diversity of the predominant bacterial phylotypes was shown to be low. Cloning and sequencing results revealed major differences between formation water and oil samples from the non-biodegraded reservoir. Bacillus sp. and Halanaerobium sp. were shown to be the predominant components of the bacterial community from the formation water sample, whereas the oil sample also included Alicyclobacillus acidoterrestris, Rhodococcus sp., Streptomyces sp. and Acidithiobacillus ferrooxidans. The PCR-DGGE technique, combined with cloning and sequencing of PCR products, revealed the presence of taxonomic groups not found previously in these samples when using cultivation-based methods and 16S rRNA gene library assembly, confirming the need of a polyphasic study in order to improve the knowledge of the extent of microbial diversity in such extreme environments. PMID:24031244

Biodegradation of potential diesel oxygenate additives: dibutyl maleate (DBM), and tripropylene glycol methyl ether (TGME).

PubMed

Marchetti, Alfredo A; Knize, Mark G; Chiarappa-Zucca, Marina L; Pletcher, Ronald J; Layton, David W

2003-08-01

The addition of oxygen-bearing compounds to diesel fuel considerably reduces particulate emissions. TGME and DBM have been identified as possible diesel additives based on their physicochemical characteristics and performance in engine tests. Although these compounds will reduce particulate emissions, their potential environmental impacts are unknown. As a means of characterizing their persistence in environmental media such as soil and groundwater, we conducted a series of biodegradation tests of DBM and TGME. Benzene and methyl tertiary butyl ether (MTBE) were also tested as reference compounds. Primary degradation of DBM fully occurred within 3 days, while TGME presented a lag phase of approximately 8 days and was not completely degraded by day 28. Benzene primary degradation occurred completely by day 3 and MTBE did not degrade at all. The total mineralized fractions of DBM and TGME achieved constant values as a function of time of approximately 65% and approximately 40%, respectively. Transport predictions show that, released to the environment, DBM and TGME would concentrate mostly in soils and waters with minimal impact to air. From an environmental standpoint, these results combined with the transport predictions indicate that DBM is a better choice than TGME as a diesel additive.

Green synthesis of metal nanoparticles: biodegradable polymers and enzymes in stabilization and surface functionalization

EPA Science Inventory

Current breakthroughs in green nanotechnology are capable to transform many of the existing processes and products that enhance environmental quality, reduce pollution, and conserve natural and non-renewable resources. Noteworthy, successful use of metal nanoparticles and 10 nano...

QSAR ANALYSIS OF SORPTION-CORRECTED RATE CONSTANTS FOR REDUCTIVE BIOTRANSFORMATION OF HALOGENATED AROMATICS

EPA Science Inventory

The inherent coupling among geochemical and microbial reactions may have significant effects on the environmental fate of a containinant. For example, sorption processes may decrease the concentration of an organic compound in solution, thereby reducing the biodegradation rate of...

Zeolite-catalyzed additions of aromatic compounds to oleic acid

USDA-ARS?s Scientific Manuscript database

There is significant research interest in developing new materials from vegetable oils and animal fats. Biobased materials can be more environmentally friendly because they tend to have good biodegradability and are derived from renewable resources. In this talk, efficient approaches for the addit...

Green Flame Retardant Cotton Highlofts for Mattresses and Upholstered Furniture

USDA-ARS?s Scientific Manuscript database

Green flame retardant (FR) barrier fabric is environmentally-friendly because it is from a natural renewable resource, biodegradable, economical, employing greige cotton that is soft to touch. Greige unbleached cotton is cheaper and softer than bleached cotton, thus, increasing its marketability par...

USE OF ALTERED MICROORGANISMS FOR FIELD BIODEGRADATION OF HAZARDOUS MATERIALS

EPA Science Inventory

The large amount of hazardous waste generated and disposed of has given rise to environmental conditions requiring remedial treatment. he use of landfills has traditionally been a cost-effective means to dispose of waste. owever, increased costs of transportation and decreasing n...

Applications and advances in phytochemical compositional analysis

USDA-ARS?s Scientific Manuscript database

The search for new functional foods, environmentally friendly pest control, bio-fuels, and biodegradable consumer products and packaging is the ongoing challenge to 21st century agriculture research, which is being met by the scientists and staff of the USDA Agricultural Research Service. Interest i...

MANAGEMENT OF PAH-IMPACTED SITES VIA IN SITU CHEMICAL CONTAINMENT AND MONITORING

EPA Science Inventory

On a world-wide basis the magnitude of environmental contamination problems involving polycyclic aromatic hydrocarbon (PAHs) is unmatched by any other group of organic chemicals. Despite the recognized limitations to PAH biodegradation (e.g., intrinsic chemical stability of the h...

Marine biodegradation of crude oil in temperate and Arctic water samples.

PubMed

Kristensen, Mette; Johnsen, Anders R; Christensen, Jan H

2015-12-30

Despite increased interest in marine oil exploration in the Arctic, little is known about the fate of Arctic offshore oil pollution. Therefore, in the present study, we examine the oil degradation potential for an Arctic site (Disko Bay, Greenland) and discuss this in relation to a temperate site (North Sea, Denmark). Biodegradation was assessed following exposure to Oseberg Blend crude oil (100 mg L(-1)) in microcosms. Changes in oil hydrocarbon fingerprints of polycyclic aromatic hydrocarbons (PAHs), alkyl-substituted PAHs, dibenzothiophenes, n-alkanes and alkyltoluenes were measured by gas chromatography-mass spectrometry (GC-MS). In the Disko Bay sample, the degradation order was n-alkanes>alkyltoluenes (para->meta->ortho-isomers)>PAHs and dibenzothiophenes, whereas, the degradation order in the North Sea samples was PAHs and dibenzothiophenes>alkyltoluenes>n-alkanes. These differences in degradation patterns significantly affect the environmental risk of oil spills and emphasise the need to consider the specific environmental conditions when conducting risk assessments of Arctic oil pollution. Copyright © 2015 Elsevier B.V. All rights reserved.

Metagenomic Analyses Reveal That Energy Transfer Gene Abundances Can Predict the Syntrophic Potential of Environmental Microbial Communities

PubMed Central

Oberding, Lisa; Gieg, Lisa M.

2016-01-01

Hydrocarbon compounds can be biodegraded by anaerobic microorganisms to form methane through an energetically interdependent metabolic process known as syntrophy. The microorganisms that perform this process as well as the energy transfer mechanisms involved are difficult to study and thus are still poorly understood, especially on an environmental scale. Here, metagenomic data was analyzed for specific clusters of orthologous groups (COGs) related to key energy transfer genes thus far identified in syntrophic bacteria, and principal component analysis was used in order to determine whether potentially syntrophic environments could be distinguished using these syntroph related COGs as opposed to universally present COGs. We found that COGs related to hydrogenase and formate dehydrogenase genes were able to distinguish known syntrophic consortia and environments with the potential for syntrophy from non-syntrophic environments, indicating that these COGs could be used as a tool to identify syntrophic hydrocarbon biodegrading environments using metagenomic data. PMID:27681901

Application of molecular docking for the degradation of organic pollutants in the environmental remediation: A review.

PubMed

Liu, Zhifeng; Liu, Yujie; Zeng, Guangming; Shao, Binbin; Chen, Ming; Li, Zhigang; Jiang, Yilin; Liu, Yang; Zhang, Yu; Zhong, Hua

2018-07-01

The molecular docking has been employed successfully to study the mechanism of biodegradation in the environmental remediation in the past few years, although medical science and biology are the main application areas for it. Molecular docking is a very convenient and low cost method to understand the reaction mechanism of proteins or enzymes with ligands with a high accuracy. This paper mainly provides a review for the application of molecular docking between organic pollutants and enzymes. It summarizes the fundamental knowledge of molecular docking, such as its theory, available softwares and main databases. Moreover, five types of pollutants, including phenols, BTEX (benzene, toluene, ethylbenzene, and xylenes), nitrile, polycyclic aromatic hydrocarbons (PAHs), and high polymer (e.g., lignin and cellulose), are discussed from molecular level. Different removal mechanisms are also explained in detail via docking technology. Even though this method shows promising application in the research of biodegradation, further studies are still needed to relate with actual condition. Copyright © 2018 Elsevier Ltd. All rights reserved.

An environmentally benign antimicrobial nanoparticle based on a silver-infused lignin core.

PubMed

Richter, Alexander P; Brown, Joseph S; Bharti, Bhuvnesh; Wang, Amy; Gangwal, Sumit; Houck, Keith; Cohen Hubal, Elaine A; Paunov, Vesselin N; Stoyanov, Simeon D; Velev, Orlin D

2015-09-01

Silver nanoparticles have antibacterial properties, but their use has been a cause for concern because they persist in the environment. Here, we show that lignin nanoparticles infused with silver ions and coated with a cationic polyelectrolyte layer form a biodegradable and green alternative to silver nanoparticles. The polyelectrolyte layer promotes the adhesion of the particles to bacterial cell membranes and, together with silver ions, can kill a broad spectrum of bacteria, including Escherichia coli, Pseudomonas aeruginosa and quaternary-amine-resistant Ralstonia sp. Ion depletion studies have shown that the bioactivity of these nanoparticles is time-limited because of the desorption of silver ions. High-throughput bioactivity screening did not reveal increased toxicity of the particles when compared to an equivalent mass of metallic silver nanoparticles or silver nitrate solution. Our results demonstrate that the application of green chemistry principles may allow the synthesis of nanoparticles with biodegradable cores that have higher antimicrobial activity and smaller environmental impact than metallic silver nanoparticles.

Injection Molding and Mechanical Properties of Bio-Based Polymer Nanocomposites.

PubMed

Mistretta, Maria Chiara; Botta, Luigi; Morreale, Marco; Rifici, Sebastiano; Ceraulo, Manuela; La Mantia, Francesco Paolo

2018-04-17

The use of biodegradable/bio-based polymers is of great importance in addressing several issues related to environmental protection, public health, and new, stricter legislation. Yet some applications require improved properties (such as barrier or mechanical properties), suggesting the use of nanosized fillers in order to obtain bio-based polymer nanocomposites. In this work, bionanocomposites based on two different biodegradable polymers (coming from the Bioflex and MaterBi families) and two different nanosized fillers (organo-modified clay and hydrophobic-coated precipitated calcium carbonate) were prepared and compared with traditional nanocomposites with high-density polyethylene (HDPE) as matrix. In particular, the injection molding processability, as well as the mechanical and rheological properties of the so-obtained bionanocomposites were investigated. It was found that the processability of the two biodegradable polymers and the related nanocomposites can be compared to that of the HDPE-based systems and that, in general, the bio-based systems can be taken into account as suitable alternatives.

Effect of filler loading and silane modification on the biodegradability of SBR composites reinforced with peanut shell powder

NASA Astrophysics Data System (ADS)

Shaniba, V.; Balan, Aparna K.; Sreejith, M. P.; Jinitha, T. V.; Subair, N.; Purushothaman, E.

2017-06-01

The development of biocomposites and their applications are important in material science due to environmental and sustainability issues. The extent of degradation depends on the nature of reinforcing filler, particle size and their modification. In this article, we tried to focus on the biodegradation of composites of Styrene Butadiene Rubber (SBR) reinforced with Peanut Shell Powder (PSP) by soil burial test. The composites of SBR with untreated PSP (UPSP) and silane modified PSP (SPSP) of 10 parts per hundred rubber (phr) and 20 phr filler loading in two particle size were buried in the garden soil for six months. The microbial degradation were assessed through the measurement of weight loss, tensile strength and hardness at definite period. The study shows that degradation increases with increase in filler loading and particle size. The chemical treatment of filler has been found to resist the degradation. The analysis of morphological properties by the SEM also confirmed biodegradation process by the microorganism in the soil.

Biodegradation of toluene by a lab-scale biofilter inoculated with Pseudomonas putida DK-1.

PubMed

Park, D W; Kim, S S; Haam, S; Ahn, I S; Kim, E B; Kim, W S

2002-03-01

The biodegradation of toluene by biofiltration inoculated with Pseudomonas putida DK-1 was investigated with variation of the several environmental parameters, such as temperature, bed length, gas flow rate and optimal humidity zone. The optimal temperature range to treat toluene gas was found to be 32-35 degrees C. Increasing the gas flow rate showed an inverse effect on the elimination capacity and the removal efficiency. The optimal gas flow rate was obtained at 65 ml min(-1) from the relation between the removal efficiency and the elimination capacity. The biodegradation rate of the toluene with respect to the bed lengths (3, 6, 9, 12 and 15 cm) increased up to 80 h but was then independent of the bed lengths after 80 h except for the 3 cm bed length. The elimination capacity was improved by about 70% compared with that reported in other literature and was also in agreement with theoretical models.

Injection Molding and Mechanical Properties of Bio-Based Polymer Nanocomposites

PubMed Central

Mistretta, Maria Chiara; Rifici, Sebastiano; Ceraulo, Manuela

2018-01-01

The use of biodegradable/bio-based polymers is of great importance in addressing several issues related to environmental protection, public health, and new, stricter legislation. Yet some applications require improved properties (such as barrier or mechanical properties), suggesting the use of nanosized fillers in order to obtain bio-based polymer nanocomposites. In this work, bionanocomposites based on two different biodegradable polymers (coming from the Bioflex and MaterBi families) and two different nanosized fillers (organo-modified clay and hydrophobic-coated precipitated calcium carbonate) were prepared and compared with traditional nanocomposites with high-density polyethylene (HDPE) as matrix. In particular, the injection molding processability, as well as the mechanical and rheological properties of the so-obtained bionanocomposites were investigated. It was found that the processability of the two biodegradable polymers and the related nanocomposites can be compared to that of the HDPE-based systems and that, in general, the bio-based systems can be taken into account as suitable alternatives. PMID:29673143

Toxicity assessment of pesticide triclosan by aquatic organisms and degradation studies.

PubMed

Taştan, Burcu Ertit; Tekinay, Turgay; Çelik, Hatice Sena; Özdemir, Caner; Cakir, Dilara Nur

2017-12-01

Triclosan is considered as an important contaminant and is widely used in personal care products as an antimicrobial agent. This study demonstrates the biodegradation of triclosan by two freshwater microalgae and the acute toxicity of triclosan and 2,4-dichlorophenol. The effects of culture media and light on biodegradation of triclosan and the changing morphology of microalgae were systematically studied. Geitlerinema sp. and Chlorella sp. degraded 82.10% and 92.83% of 3.99 mg/L of triclosan at 10 days, respectively. The microalgal growth inhibition assay confirmed absence of toxic effects of triclosan on Chlorella sp., even at higher concentration (50 mg/L) after 72 h exposure. HPLC analysis showed that 2,4-dichlorophenol was produced as degradation product of triclosan by Geitlerinema sp. and Chlorella sp. This study proved to be beneficial to understand biodegradation and acute toxicity of triclosan by microalgae in order to provide aquatic environmental protection. Copyright © 2017 Elsevier Inc. All rights reserved.

A review of the occurrence, analyses, toxicity, and biodegradation of naphthenic acids.

PubMed

Clemente, Joyce S; Fedorak, Phillip M

2005-07-01

Naphthenic acids occur naturally in crude oils and in oil sands bitumens. They are toxic components in refinery wastewaters and in oil sands extraction waters. In addition, there are many industrial uses for naphthenic acids, so there is a potential for their release to the environment from a variety of activities. Studies have shown that naphthenic acids are susceptible to biodegradation, which decreases their concentration and reduces toxicity. This is a complex group of carboxylic acids with the general formula CnH(2n+Z)O2, where n indicates the carbon number and Z specifies the hydrogen deficiency resulting from ring formation. Measuring the concentrations of naphthenic acids in environmental samples and determining the chemical composition of a naphthenic acids mixture are huge analytical challenges. However, new analytical methods are being applied to these problems and progress is being made to better understand this mixture of chemically similar compounds. This paper reviews a variety of analytical methods and their application to assessing biodegradation of naphthenic acids.

Recent advances in biopolymers and biopolymer-based nanocomposites for food packaging materials.

PubMed

Tang, X Z; Kumar, P; Alavi, S; Sandeep, K P

2012-01-01

Plastic packaging for food and non-food applications is non-biodegradable, and also uses up valuable and scarce non-renewable resources like petroleum. With the current focus on exploring alternatives to petroleum and emphasis on reduced environmental impact, research is increasingly being directed at development of biodegradable food packaging from biopolymer-based materials. The proposed paper will present a review of recent developments in biopolymer-based food packaging materials including natural biopolymers (such as starches and proteins), synthetic biopolymers (such as poly lactic acid), biopolymer blends, and nanocomposites based on natural and synthetic biopolymers. The paper will discuss the various techniques that have been used for developing cost-effective biodegradable packaging materials with optimum mechanical strength and oxygen and moisture barrier properties. This is a timely review as there has been a recent renewed interest in research studies, both in the industry and academia, towards development of a new generation of biopolymer-based food packaging materials with possible applications in other areas.

Chemical and ecotoxicological properties of three bio-oils from pyrolysis of biomasses.

PubMed

Campisi, Tiziana; Samorì, Chiara; Torri, Cristian; Barbera, Giuseppe; Foschini, Anna; Kiwan, Alisar; Galletti, Paola; Tagliavini, Emilio; Pasteris, Andrea

2016-10-01

In view of the potential use of pyrolysis-based technologies, it is crucial to understand the environmental hazards of pyrolysis-derived products, in particular bio-oils. Here, three bio-oils were produced from fast pyrolysis of pine wood and intermediate pyrolysis of corn stalk and poultry litter. They were fully characterized by chemical analysis and tested for their biodegradability and their ecotoxicity on the crustacean Daphnia magna and the green alga Raphidocelis subcapitata. These tests were chosen as required by the European REACH regulation. These three bio-oils were biodegradable, with 40-60% of biodegradation after 28 days, and had EC50 values above 100mgL(-1) for the crustacean and above 10mgL(-1) for the alga, showing low toxicity to the aquatic life. The toxic unit approach was applied to verify whether the observed toxicity could be predicted from the data available for the substances detected in the bio-oils. The predicted values largely underestimated the experimental values. Copyright © 2016 Elsevier Inc. All rights reserved.

Food loss and waste management in Turkey.

PubMed

Salihoglu, Guray; Salihoglu, Nezih Kamil; Ucaroglu, Selnur; Banar, Mufide

2018-01-01

Food waste can be an environmental and economic problem if not managed properly but it can meet various demands of a country if it is considered as a resource. The purpose of this report is to review the existing state of the field in Turkey and identify the potential of food waste as a resource. Food loss and waste (FLW) was examined throughout the food supply chain (FSC) and quantified using the FAO model. Edible FLW was estimated to be approximately 26milliontons/year. The amount of biodegradable waste was estimated based on waste statistics and research conducted on household food waste in Turkey. The total amount of biodegradable waste was found to be approximately 20milliontons/year, where more than 8.6milliontons/year of this waste is FLW from distribution and consumption in the FSC. Options for the end-of-life management of biodegradable wastes are also discussed in this review article. Copyright © 2017 Elsevier Ltd. All rights reserved.

Biotreatment of textile effluent in static bioreactor by Curvularia lunata URM 6179 and Phanerochaete chrysosporium URM 6181.

PubMed

Miranda, Rita de Cássia M de; Gomes, Edelvio de Barros; Pereira, Nei; Marin-Morales, Maria Aparecida; Machado, Katia Maria Gomes; Gusmão, Norma Buarque de

2013-08-01

Investigations on biodegradation of textile effluent by filamentous fungi strains Curvularia lunata URM 6179 and Phanerochaete chrysosporium URM 6181 were performed in static bioreactors under aerated and non-aerated conditions. Spectrophotometric, HPLC/UV and LC-MS/MS analysis were performed as for to confirm, respectively, decolourisation, biodegradation and identity of compounds in the effluent. Enzymatic assays revealed higher production of enzymes laccase (Lac), lignin peroxidase (LiP) and manganese-dependent peroxidase (MnP) by P. chrysosporium URM 6181 in aerated bioreactor (2020; 39 and 392 U/l, respectively). Both strains decolourised completely the effluent after ten days and biodegradation of the most predominant indigo dye was superior in aerated bioreactor (96%). Effluent treated by P. chrysosporium URM 6181 accumulated a mutagenic metabolite derived from indigo. The C. lunata URM 6179 strain, showed to be more successful for assure the environmental quality of treated effluent. These systems were found very effective for efficient fungal treatment of textile effluent. Copyright © 2013 Elsevier Ltd. All rights reserved.

Contribution of microorganisms to non-extractable residue formation during biodegradation of ibuprofen in soil.

PubMed

Nowak, Karolina M; Girardi, Cristobal; Miltner, Anja; Gehre, Matthias; Schäffer, Andreas; Kästner, Matthias

2013-02-15

Non-extractable residues (NER) formed during biodegradation of organic contaminants in soil are considered to be mainly composed of parent compounds or their primary metabolites with hazardous potential. However, in the case of biodegradable organic compounds, the soil NER may also contain microbial biomass components, for example fatty acids (FA) and amino acids (AA). After cell death, these biomolecules are subsequently incorporated into non-living soil organic matter (SOM) and are stabilised ultimately forming hardly extractable residues of biogenic origin. We investigated biodegradation of (13)C(6)-ibuprofen, in particular the metabolic incorporation of the (13)C-label into FA and AA and their fate in soil over 90 days. (13)C-FA and (13)C-AA amounts in the living microbial biomass fraction initially increased, then decreased over time and were continuously incorporated into the non-living SOM pool. The (13)C-FA in the non-living SOM remained stable from day 59 whereas the contents of (13)C-AA slightly increased until the end. After 90 days, nearly all NER were biogenic as they were made up almost completely by natural biomass compounds. The presented data demonstrated that the potential environmental risks related to the ibuprofen-derived NER are overestimated. Copyright © 2012 Elsevier B.V. All rights reserved.

Bacterial production of the biodegradable plastics polyhydroxyalkanoates.

PubMed

Urtuvia, Viviana; Villegas, Pamela; González, Myriam; Seeger, Michael

2014-09-01

Petroleum-based plastics constitute a major environmental problem due to their low biodegradability and accumulation in various environments. Therefore, searching for novel biodegradable plastics is of increasing interest. Microbial polyesters known as polyhydroxyalkanoates (PHAs) are biodegradable plastics. Life cycle assessment indicates that PHB is more beneficial than petroleum-based plastics. In this report, bacterial production of PHAs and their industrial applications are reviewed and the synthesis of PHAs in Burkholderia xenovorans LB400 is described. PHAs are synthesized by a large number of microorganisms during unbalanced nutritional conditions. These polymers are accumulated as carbon and energy reserve in discrete granules in the bacterial cytoplasm. 3-hydroxybutyrate and 3-hydroxyvalerate are two main PHA units among 150 monomers that have been reported. B. xenovorans LB400 is a model bacterium for the degradation of polychlorobiphenyls and a wide range of aromatic compounds. A bioinformatic analysis of LB400 genome indicated the presence of pha genes encoding enzymes of pathways for PHA synthesis. This study showed that B. xenovorans LB400 synthesize PHAs under nutrient limitation. Staining with Sudan Black B indicated the production of PHAs by B. xenovorans LB400 colonies. The PHAs produced were characterized by GC-MS. Diverse substrates for the production of PHAs in strain LB400 were analyzed. Copyright © 2014 Elsevier B.V. All rights reserved.

Identification of metabolites involved in the biodegradation of the ionic liquid 1-butyl-3-methylpyridinium bromide by activated sludge microorganisms.

PubMed

Pham, Thi Phuong Thuy; Cho, Chul-Woong; Jeon, Che-Ok; Chung, Yun-Jo; Lee, Min-Woo; Yun, Yeoung-Sang

2009-01-15

Ionic liquids (ILs) are low melting organic salts that potentially comprise wide application due to their fascinating properties and have emerged as promising "green" replacements for volatile organic solvents. Despite their nonmeasurable vapor pressure, some quantities of ILs will soon be present in effluent discharges since they do have significant solubility in water. Recently, the toxic effects of ILs toward aquatic communities have been intensively investigated, but little information is available concerning the biodegradable properties of these compounds. The objective of this study was to identify the metabolites generated during the biotransformation of 1-butyl-3-methylpyridinium by microorganisms in aerobic activated sludge. The obtained results revealed that the alkylpyridinium salt was metabolized through the sequential oxidization in different positions of the alkyl side chains. High-performance liquid chromatography and mass-spectrometry analyses demonstrated that this biodegradation led to the formation of 1-hydroxybutyl-3-methylpyridinium, 1-(2-hydroxybutal)-3-methylpyridinium, 1-(2-hydroxyethyl)-3-methylpyridinium, and methylpyridine. On the basis of these intermediate products, biodegradation pathways were also suggested. These findings provide the basic information that might be useful for assessing the factors related to the environmental fate and behavior of this commonly used pyridinium IL.

Fabrication, characterization, and modeling of a biodegradable battery for transient electronics

NASA Astrophysics Data System (ADS)

Edupuganti, Vineet; Solanki, Raj

2016-12-01

Traditionally, emphasis has been placed on durable, long-lasting electronics. However, electronics that are meant to intentionally degrade over time can actually have significant practical applications. Biodegradable, or transient, electronics would open up opportunities in the field of medical implants, where the need for surgical removal of devices could be eliminated. Environmental sensors and, eventually, consumer electronics would also greatly benefit from this technology. An essential component of transient electronics is the battery, which serves as a biodegradable power source. This work involves the fabrication, characterization, and modeling of a magnesium-based biodegradable battery. Galvanostatic discharge tests show that an anode material of magnesium alloy AZ31 extends battery lifetime by over six times, as compared to pure magnesium. With AZ31, the maximum power and capacity of the fabricated device are 67 μW and 5.2 mAh, respectively, though the anode area is just 0.8 cm2. The development of an equivalent circuit model provided insight into the battery's behavior by extracting fitting parameters from experimental data. The model can accurately simulate device behavior, taking into account its intentional degradation. The size of the device and the power it produces are in accordance with typical levels for low-power transient systems.

Accelerated biodegradation of BPA in water-sediment microcosms with Bacillus sp. GZB and the associated bacterial community structure.

PubMed

Xiong, Jukun; An, Taicheng; Li, Guiying; Peng, Ping'an

2017-10-01

Bisphenol A (BPA) is a synthetic chemical primarily used to produce polycarbonate plastics and epoxy resins. Significant industrial and consumer's consumption of BPA-containing products has contributed to extensive contamination in different environmental matrices. In this study, microcosms bioaugmented with Bacillus sp. GZB were constructed to investigate BPA biodegradation, identify the main bacterial community, and evaluate bacterial community responses in the microcosms. Under aerobic conditions, BPA was quickly depleted as a result of bioaugmentation with Bacillus sp. GZB in water-sediment contaminated with pollutants. The pollutants used were generally associated with the electronic wastes (mobile phones, computers, televisions) dismantling process. Adding BPA affected the bacterial community composition in the water-sediment. Furthermore, BPA biodegradation was enhanced by adding electron donors/co-substrates: humic acid, NaCl, glucose, and yeast extract. Metagenomic analysis of the total 16S rRNA genes from the BPA-degrading microcosms with bioaugmentation illustrated that the genera Bacillus, Thiobacillus, Phenylobacterium, and Cloacibacterium were dominant after a 7-week incubation period. A consortium of microorganisms from different bacterial genera may be involved in BPA biodegradation in electronic waste contaminated water-sediment. This study provides new insights about BPA bioaugmentation and bacterial ecology in the BPA-degrading environment. Copyright © 2017 Elsevier Ltd. All rights reserved.

Comparative study of biodegradability prediction of chemicals using decision trees, functional trees, and logistic regression.

PubMed

Chen, Guangchao; Li, Xuehua; Chen, Jingwen; Zhang, Ya-Nan; Peijnenburg, Willie J G M

2014-12-01

Biodegradation is the principal environmental dissipation process of chemicals. As such, it is a dominant factor determining the persistence and fate of organic chemicals in the environment, and is therefore of critical importance to chemical management and regulation. In the present study, the authors developed in silico methods assessing biodegradability based on a large heterogeneous set of 825 organic compounds, using the techniques of the C4.5 decision tree, the functional inner regression tree, and logistic regression. External validation was subsequently carried out by 2 independent test sets of 777 and 27 chemicals. As a result, the functional inner regression tree exhibited the best predictability with predictive accuracies of 81.5% and 81.0%, respectively, on the training set (825 chemicals) and test set I (777 chemicals). Performance of the developed models on the 2 test sets was subsequently compared with that of the Estimation Program Interface (EPI) Suite Biowin 5 and Biowin 6 models, which also showed a better predictability of the functional inner regression tree model. The model built in the present study exhibits a reasonable predictability compared with existing models while possessing a transparent algorithm. Interpretation of the mechanisms of biodegradation was also carried out based on the models developed. © 2014 SETAC.

Biodegradation test of SPS-LS blends as polymer electrolyte membrane fuel cells

NASA Astrophysics Data System (ADS)

Putri, Zufira; Arcana, I. Made

2014-03-01

Sulfonated polystyrene (SPS) can be applied as a proton exchange membrane fuel cell due to its fairly good chemical stability. In order to be applied as polymer electrolyte membrane fuel cells (PEMFCs), membrane polymer should have a good ionic conductivity, high proton conductivity, and high mechanical strength. Lignosulfonate (LS) is a complex biopolymer which has crosslinks and sulfonate groups. SPS-LS blends with addition of SiO2 are used to increase the proton conductivity and to improve the mechanical properties and thermal stability. However, the biodegradation test of SPS-LS blends is required to determine whether the application of these membranes to be applied as an environmentally friendly membrane. In this study, had been done the synthesis of SPS, biodegradability test of SPS-LS blends with variations of LS and SiO2 compositions. The biodegradation test was carried out in solid medium of Luria Bertani (LB) with an activated sludge used as a source of microorganism at incubation temperature of 37°C. Based on the results obtained indicated that SPS-LS-SiO2 blends are more decomposed by microorganism than SPS-LS blends. This result is supported by analysis of weight reduction percentage, functional groups with Fourier Transform Infrared (FTIR) Spectroscopy, and morphological surface with Scanning Electron Microscopy (SEM).

ELECTROSPUN MESOFIBERS, A NOVEL BIODEGRADABLE PHEROMONE DISPENSER TECHNOLOGY, ARE COMBINED WITH MECHANICAL DEPLOYMENT FOR EFFICIENT IPM OF LOBESIA BOTRANA IN VINEYARDS.

PubMed

Hummel, Hans E; Langner, S S; Breuer, M

2015-01-01

Behaviour modifying pheromones are well known agents for disrupting mating communication of pest insects. For optimal activity, they must be dispensed in time and space at a quantitatively measurable, predetermined release rate covering the flight period of the target species. Pheromones appeal to environmentally conscientious entomologists for their biodegradability, non-toxicity and ecological compatibility. In attempts of combining the virtues of pheromones, suitable slow release dispensers, and their mechanical deployment, an ecologically sensible, reasonably priced and patented procedure was developed and tested with the vineyard pest Lobesia botrana (Lep.: Tortricidae). It is characterized by (1) Electrospun mesofibers with diameters ranging from 0.6 to 3.5 micrometres, containing disruptants and dispensing it by slow release diffusion into the crop, (2) simultaneous application of the fully biodegradable combination of pheromone with Ecoflex polyester mesofiber, (3) combination of mechanical deployment by multi-purpose cultivators of the prefabricated pheromone dispensers with other simultaneous cultivation measures, and thus further reducing labour time and treatment costs. The dispensers are biodegradable within half a year without leaving any objectionable residues. In the standard eco-toxicology tests pheromone dispensers are harmless to non-target organisms. The disruptive effect of one treatment lasts for seven weeks which covers well one of several flight periods of L. botrana.

(Eco)toxicity and biodegradability of selected protic and aprotic ionic liquids.

PubMed

Peric, Brezana; Sierra, Jordi; Martí, Esther; Cruañas, Robert; Garau, Maria Antonia; Arning, Jürgen; Bottin-Weber, Ulrike; Stolte, Stefan

2013-10-15

Ionic liquids (ILs) are a promising group of compounds with a large variety of possible structures and uses. They are considered as a potential "green" replacement for traditional volatile organic solvents, but their impact on the environment is often neglected or not studied enough. In the present study, selected representatives of two ILs groups were analyzed: a new family of protic ILs (derived from aliphatic amines and organic acids) and some frequently used aprotic ILs (substituted imidazolium and piridinium chlorides). The aquatic toxicity (test organisms Vibrio fischeri, Pseudokirchneriella subcapitata and Lemna minor) and biodegradability tests were carried out. The additional tests with enzyme (acetylcholinesterase) and leukemia rat cells (IPC-81) provided more in-depth evaluation of toxicity. In our comparative hazard assessment protic ILs have EC50 values >100 mg L(-1) in all of the tests performed, except in the case of three representatives toward Lemna minor. They also show good biodegradability rates. The EC50 values for aprotic ILs are various orders of magnitude lower than the ones for protic ILs in most of the tests and they show a lower biodegradability potential. These findings indicate that protic ILs can be considered as environmentally safer alternatives for more toxic ILs and organic solvents. Copyright © 2013 Elsevier B.V. All rights reserved.

Field and laboratory evidence for intrinsic biodegradation of vinyl chloride contamination in a Fe(III)-reducing aquifer

USGS Publications Warehouse

Bradley, P.M.; Chapelle, F.H.; Wilson, J.T.

1998-01-01

Intrinsic bioremediation of chlorinated ethenes in anaerobic aquifers previously has not been considered feasible, due, in large part, to 1) the production of vinyl chloride during microbial reductive dechlorination of higher chlorinated contaminants and 2) the apparent poor biodegradability of vinyl chloride under anaerobic conditions. In this study, a combination of field geochemical analyses and laboratory radiotracer ([1,2-14C] vinyl chloride) experiments was utilized to assess the potential for intrinsic biodegradation of vinyl chloride contamination in an Fe(III)-reducing, anaerobic aquifer. Microcosm experiments conducted under Fe(III)-reducing conditions with material from the Fe(III)-reducing, chlorinated-ethene contaminated aquifer demonstrated significant oxidation of [1,2-14C] vinyl chloride to 14CO2 with no detectable production of ethene or other reductive dehalogenation products. Rates of degradation derived from the microcosm experiments (0.9-1.3% d-1) were consistent with field-estimated rates (0.03-0.2% d-1) of apparent vinyl chloride degradation. Field estimates of apparent vinyl chloride biodegradation were calculated using two distinct approaches; 1) a solute dispersion model and 2) a mass balance assessment. These findings demonstrate that degradation under Fe(III) reducing conditions can be an environmentally significant mechanism for intrinsic bioremediation of vinyl chloride in anaerobic ground-water systems.

An environmentally benign antimicrobial nanoparticle based on a silver-infused lignin core

EPA Science Inventory

Silver nanoparticles have antibacterial properties but their use has been a cause for concern because they persist in the environment. Here we show that lignin nanoparticles infused with silver ions and coated with a cationic polyelectrolyte layer form a biodegradable and green a...

Strategic Environmental Research and Development Program, Fiscal Year 2007

DTIC Science & Technology

2008-02-01

NDMA ), a product of rocket fuel, in groundwater...National Association of Ordnance Contractors iv Acronyms and Abbreviations (continued) NBVC Naval Base Ventura County NDMA N...Berkeley • Abiotic and Biotic Mechanisms Controlling In Situ Remediation of NDMA (ER-1421), Pacific Northwest National Laboratory • Biodegradation

Biodegradation of Guanidinium By Aquatic Microorganisms.

DTIC Science & Technology

1985-12-01

16 * Metabolism of Guanidinium at Environmental Concentrations ............... 20 - DISCUSSION...17 * 4. Short-Term Metabolism of Guanidinium and Urea by Monocacy River Microorganisms...classical study has indicated that it can serve as a nitrogen source for growth of several bacterial and fungal species in pure cultures.9 Soil micro

Preparation and characterization of a novel micro- and nanocomposite hydrogels containing cellulosic fibrils

USDA-ARS?s Scientific Manuscript database

In recent years, the preparation of cellulosic composites and nanocomposites has become an important approach because of the wide abundance of cellulose, its biodegradability, renewability, and the ability to effectively reinforce a polymer matrix in an environmentally benign nature. The main object...

Biodegradation of brominated and organophosphorus flame retardants.

PubMed

Waaijers, Susanne L; Parsons, John R

2016-04-01

Brominated flame retardants account for about 21% of the total production of flame retardants and many of these have been identified as persistent, bioaccumulative and toxic. Nevertheless, debromination of these chemicals under anaerobic conditions is well established, although this can increase their toxicity. Consequently, the production and use of these chemicals has been restricted and alternative products have been developed. Many of these are brominated compounds and share some of the disadvantages of the chemicals they are meant to replace. Therefore, other, nonbrominated, flame retardants such as organophosphorus compounds are also being used in increasing quantities, despite the fact that knowledge of their biodegradation and environmental fate is often lacking. Copyright © 2015 Elsevier Ltd. All rights reserved.

Biodegradable Cellulose-based Hydrogels: Design and Applications

PubMed Central

Sannino, Alessandro; Demitri, Christian; Madaghiele, Marta

2009-01-01

Hydrogels are macromolecular networks able to absorb and release water solutions in a reversible manner, in response to specific environmental stimuli. Such stimuli-sensitive behaviour makes hydrogels appealing for the design of ‘smart’ devices, applicable in a variety of technological fields. In particular, in cases where either ecological or biocompatibility issues are concerned, the biodegradability of the hydrogel network, together with the control of the degradation rate, may provide additional value to the developed device. This review surveys the design and the applications of cellulose-based hydrogels, which are extensively investigated due to the large availability of cellulose in nature, the intrinsic degradability of cellulose and the smart behaviour displayed by some cellulose derivatives.

Study of environmental biodegradation of LDPE films in soil using optical and scanning electron microscopy.

PubMed

Mumtaz, Tabassum; Khan, M R; Hassan, Mohd Ali

2010-07-01

An outdoor soil burial test was carried out to evaluate the degradation of commercially available LDPE carrier bags in natural soil for up to 2 years. Biodegradability of low density polyethylene films in soil was monitored using both optical and scanning electron microscopy (SEM). After 7-9 months of soil exposure, microbial colonization was evident on the film surface. Exposed LDPE samples exhibit progressive changes towards degradation after 17-22 months. SEM images reveal signs of degradation such as exfoliation and formation of cracks on film leading to disintegration. The possible degradation mode and consequences on the use and disposal of LDPE films is discussed. Copyright 2010 Elsevier Ltd. All rights reserved.

Phytoremediation and bioremediation of polychlorinated biphenyls (PCBs): state of knowledge and research perspectives.

PubMed

Passatore, Laura; Rossetti, Simona; Juwarkar, Asha A; Massacci, Angelo

2014-08-15

This review summarizes the bioremediation and phytoremediation technologies proposed so far to detoxify PCB-contaminated sites. A critical analysis about the potential and limits of the PCB pollution treatment strategies by means of plants, fungi and bacteria are elucidated, including the new insights emerged from recent studies on the rhizosphere potential and on the implementation of simultaneous aerobic and anaerobic biodegradation processes. The review describes the biodegradation and phytoremediation processes and elaborates on the environmental variables affecting contaminant degradation rates, summarizing the amendments recommended to enhance PCB degradation. Additionally, issues connected with PCB toxicology, actual field remediation strategies and economical evaluation are discussed. Copyright © 2014 Elsevier B.V. All rights reserved.

Mathematical modelling of oil spill fate and transport in the marine environment incorporating biodegradation kinetics of oil droplets

NASA Astrophysics Data System (ADS)

Spanoudaki, Katerina

2016-04-01

Oil biodegradation by native bacteria is one of the most important natural processes that can attenuate the environmental impacts of marine oil spills. However, very few numerical models of oil spill fate and transport include biodegradation kinetics of spilled oil. Furthermore, in models where biodegradation is included amongst the oil transformation processes simulated, it is mostly represented as a first order decay process neglecting the effect of several important parameters that can limit biodegradation rate, such as oil composition and oil droplets-water interface. To this end, the open source numerical model MEDSKIL-II, which simulates oil spill fate and transport in the marine environment, has been modified to include biodegradation kinetics of oil droplets dispersed in the water column. MEDSLIK-II predicts the transport and weathering of oil spills following a Lagrangian approach for the solution of the advection-diffusion equation. Transport is governed by the 3D sea currents and wave field provided by ocean circulation models. In addition to advective and diffusive displacements, the model simulates several physical and chemical processes that transform the oil (evaporation, emulsification, dispersion in the water column, adhesion to coast). The fate algorithms employed in MEDSLIK-II consider the oil as a uniform substance whose properties change as the slick weathers, an approach that can lead to reduced accuracy, especially in the estimation of oil evaporation and biodegradation. Therefore MEDSLIK-II has been modified by adopting the "pseudo-component" approach for simulating weathering processes. Spilled oil is modelled as a relatively small number of discrete, non-interacting components (pseudo-components). Chemicals in the oil mixture are grouped by physical-chemical properties and the resulting pseudo-component behaves as if it were a single substance with characteristics typical of the chemical group. The fate (evaporation, dispersion, biodegradation) of each component is tracked separately. Biodegradation of oil droplets is modelled by Monod kinetics. The kinetics of oil particles size reduction due to the microbe-mediated degradation at water-oil particle interface is represented by the shrinking core model. In order to test the performance of the modified MEDSLIK-II model, it has been applied to a test case built-in the original code. The total fate of the oil spill is simulated both without biodegradation kinetics and when biodegradation is taken into account, for reasons of comparison. Several parameters that control biodegradation rate, including initial oil concentration and composition, size distribution of oil droplets and initial microbial concentration have been investigated. This upgraded version of MEDSLIK-II can be useful not only for predicting the transport and fate of spilled oil in the short term but also for evaluating different bioremediation strategies and risk assessment for the mid- and long term. Acknowledgements: The financial support by the EU project DECATASTROPHIZE: Use of SDSS and MCDA to Prepare for Disasters or Plan for Multiple Hazards, GA no. ECHO/SUB/2015/713788/PREP02, is greatly acknowledged.

Bilastine: an environmental risk assessment.

PubMed

Lucero, María Luisa; Peither, Armin; Ledo, Francisco

2015-10-01

Bilastine is a new oral selective, non-sedating histamine H1 antagonist for the symptomatic treatment of allergic rhinoconjunctivitis and urticaria. The European Medicines Agency requires an Environmental Risk Assessment (ERA) for all novel medicines for human use. To calculate the bilastine predicted environmental concentration in surface water (PECsw; phase I ERA), and to determine the effects of bilastine on aquatic systems (phase II [tier A]). Bilastine PECsw was calculated using the maximum daily dosage (20 mg), assuming that all administered bilastine was released into the aquatic environment. A persistence, bioaccumulation and toxicity assessment was conducted using the log Kow from the molecular structure. In phase II (tier A), a ready biodegradability test was performed, and bilastine's potential toxicity to various aquatic and sediment-dwelling micro-organisms was evaluated. Bilastine PECSW was calculated as 0.1 μg L(-1), and the compound was not readily biodegradable. Bilastine had no significant effects on Chironomus riparius midges, or on the respiration rate of activated sludge. For green algae, the bilastine no observed effect concentration (NOEC) was 22 mg L(-1); bilastine had no effect on zebra fish development, or on the reproduction rate of daphnids. Bilastine NOEC values against zebra fish, algae, daphnids, and aerobic organisms in activated sludge were at least 130 000-fold greater than the calculated PECSW value. No environmental concerns exist from bilastine use in patients with allergic rhinoconjunctivitis or urticaria.

Fabrication of environmentally biodegradable lignin nanoparticles.

PubMed

Frangville, Camille; Rutkevičius, Marius; Richter, Alexander P; Velev, Orlin D; Stoyanov, Simeon D; Paunov, Vesselin N

2012-12-21

We developed a method for the fabrication of novel biodegradable nanoparticles (NPs) from lignin which are apparently non-toxic for microalgae and yeast. We compare two alternative methods for the synthesis of lignin NPs which result in particles of very different stability upon change of pH. The first method is based on precipitation of low-sulfonated lignin from an ethylene glycol solution by using diluted acidic aqueous solutions, which yields lignin NPs that are stable over a wide range of pH. The second approach is based on the acidic precipitation of lignin from a high-pH aqueous solution which produces NPs stable only at low pH. Our study reveals that lignin NPs from the ethylene glycol-based precipitation contain densely packed lignin domains which explain the stability of the NPs even at high pH. We characterised the properties of the produced lignin NPs and determined their loading capacities with hydrophilic actives. The results suggest that these NPs are highly porous and consist of smaller lignin domains. Tests with microalgae like Chlamydomonas reinhardtii and yeast incubated in lignin NP dispersions indicated that these NPs lack measurable effect on the viability of these microorganisms. Such biodegradable and environmentally compatible NPs can find applications as drug delivery vehicles, stabilisers of cosmetic and pharmaceutical formulations, or in other areas where they may replace more expensive and potentially toxic nanomaterials. Copyright © 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Production of low-cost polyesters by microwaving heating of carboxylic acids and polyol blends

USDA-ARS?s Scientific Manuscript database

Numerous issues such as price uncertainty, manufacturing costs, environmental disposal, and geo-political issues affect the petroleum-based polymer industry. As an alternative, increasing interest in the development of biodegradable non-petroleum-based polymers has risen steadily since the 1980s. Ho...

48 CFR 552.238-72 - Identification of Products That Have Environmental Attributes.

Code of Federal Regulations, 2010 CFR

2010-10-01

.... Several examples of these characteristics are biodegradable, recyclable, reduced pollutants, ozone safe, and low volatile organic compounds (VOCs). Post-consumer material means a material or finished product... life as a consumer item. Post-consumer material is part of the broader category of “recovered material...

Toxicity threshold of chitosan for the subterranean termite, Reticulitermes flavipes

Treesearch

Olanrewaju Raji; Telmah Telmadarrehei; Juliet D. Tang; Dragica Jeremic

2015-01-01

Chitosan is a hydrophilic and biodegradable polysaccharide with antimicrobial properties. It has low toxicity to non-target organisms and is considered an environmentally friendly preservative. In this study, the efficacy of chitosan polymer (> 50 kDa) as a wood preservative was evaluated against the subterranean termites Reticulitermes flavipes...

Ammonium and skatole biodegradation by swine waste microflora in a flow-through bioreactor

USDA-ARS?s Scientific Manuscript database

Animal waste disposal and odor control have become a major issue for animal production facilities. As an attempt to improve efficiency and profit margins, many livestock operations have become large concentrated rearing facilities. As a result, many concerns over potentially adverse environmental im...

Environmental Research Brief. ANAEROBIC BIODEGREDATION OF BTEX IN AQUIFER MATERIAL (EPA/600/S-97/003)

EPA Science Inventory

This study focuses on the anaerobic biodegradation of benzene, toluene, ethylbenzene and xylene isomers (BTEX) in aquifer material from two petroleum-contaminated aquifers; Sleeping Bear Dunes National Lakeshore (SB) in Michigan and a site near Rocky Point, North Carolina (RP). T...

Bioplastic made from corn starch as an effective biological delivery vehicle for control of agricultural pests

USDA-ARS?s Scientific Manuscript database

In recent years, increasing consumer sensitivity to environmental sustainability and favorable legislation has resulted in a rising demand for renewable and bio-based products, including biodegradable plastic. A recent market research report has projected a 15% annual increase in the demand of biode...

APPLICATION OF STABLE CARBON AND HYDROGEN ISOTOPIC TECHNIQUES FOR MONITORING BIODEGRADATION OF MTBE IN THE FIELD

EPA Science Inventory

A significant challenge in environmental studies is to determine the onset and extent of MTBE bioremediation at an affected site, which may involve indirect approaches such as microcosm verification of microbial activities at a given site. Stable isotopic fractionation is cha...

Generation of Valuable Nanomaterials Using Biodegradable Waste: Rags to Riches Story of Red Grape Pomace

EPA Science Inventory

In our sustainable research endeavors pertaining to environmental remediation, we envisioned utilizing winery waste, red grape pomace, as a primary source for the dual role of reduction of inorganic salts and capping of the ensuing nanomaterials This study shows that red grape po...

Vault Nanoparticles Packaged with Enzymes as an Efficient Pollutant Biodegradation Technology.

PubMed

Wang, Meng; Abad, Danny; Kickhoefer, Valerie A; Rome, Leonard H; Mahendra, Shaily

2015-11-24

Vault nanoparticles packaged with enzymes were synthesized as agents for efficiently degrading environmental contaminants. Enzymatic biodegradation is an attractive technology for in situ cleanup of contaminated environments because enzyme-catalyzed reactions are not constrained by nutrient requirements for microbial growth and often have higher biodegradation rates. However, the limited stability of extracellular enzymes remains a major challenge for practical applications. Encapsulation is a recognized method to enhance enzymatic stability, but it can increase substrate diffusion resistance, lower catalytic rates, and increase the apparent half-saturation constants. Here, we report an effective approach for boosting enzymatic stability by single-step packaging into vault nanoparticles. With hollow core structures, assembled vault nanoparticles can simultaneously contain multiple enzymes. Manganese peroxidase (MnP), which is widely used in biodegradation of organic contaminants, was chosen as a model enzyme in the present study. MnP was incorporated into vaults via fusion to a packaging domain called INT, which strongly interacts with vaults' interior surface. MnP fused to INT and vaults packaged with the MnP-INT fusion protein maintained peroxidase activity. Furthermore, MnP-INT packaged in vaults displayed stability significantly higher than that of free MnP-INT, with slightly increased Km value. Additionally, vault-packaged MnP-INT exhibited 3 times higher phenol biodegradation in 24 h than did unpackaged MnP-INT. These results indicate that the packaging of MnP enzymes in vault nanoparticles extends their stability without compromising catalytic activity. This research will serve as the foundation for the development of efficient and sustainable vault-based bioremediation approaches for removing multiple contaminants from drinking water and groundwater.

Isolation and characterization of Arctic microorganisms decomposing bioplastics.

PubMed

Urbanek, Aneta K; Rymowicz, Waldemar; Strzelecki, Mateusz C; Kociuba, Waldemar; Franczak, Łukasz; Mirończuk, Aleksandra M

2017-12-01

The increasing amount of plastic waste causes significant environmental pollution. In this study, screening of Arctic microorganisms which are able to degrade bioplastics was performed. In total, 313 microorganisms were isolated from 52 soil samples from the Arctic region (Spitsbergen). Among the isolated microorganisms, 121 (38.66%) showed biodegradation activity. The ability of clear zone formation on emulsified poly(butylene succinate-co-adipate) (PBSA) was observed for 116 microorganisms (95.87%), on poly(butylene succinate) (PBS) for 73 microorganisms (60.33%), and on poly(ɛ-caprolactone) (PCL) for 102 microorganisms (84.3%). Moreover, the growth of microorganisms on poly(lactic acid) (PLA) agar plates was observed for 56 microorganisms (46.28%). Based on the 16S rRNA sequence, 10 bacterial strains which showed the highest ability for biodegradation were identified as species belonging to Pseudomonas sp. and Rhodococcus sp. The isolated fungal strains were tested for polycaprolactone films and commercial corn and potato starch bags degradation under laboratory conditions. Strains 16G (based on the analysis of a partial 18S rRNA sequence, identified as Clonostachys rosea) and 16H (identified as Trichoderma sp.) showed the highest capability for biodegradation. A particularly high capability for biodegradation was observed for the strain Clonostachys rosea, which showed 100% degradation of starch films and 52.91% degradation of PCL films in a 30-day shake flask experiment. The main advantage of the microorganisms isolated from Arctic environment is the ability to grow at low temperature and efficient biodegradation under this condition. The data suggest that C. rosea can be used in natural and laboratory conditions for degradations of bioplastics.

In situ lubricant degradation in Antarctic marine sediments. 1. Short-term changes.

PubMed

Thompson, Belinda A W; Davies, Noel W; Goldsworthy, Paul M; Riddle, Martin J; Snape, Ian; Stark, Jonathan S

2006-02-01

A large-scale, in situ experiment was set up near the Bailey Peninsula area (Casey Station, East Antarctica) to monitor the natural attenuation of synthetic lubricants in marine sediments over five years. Here, we report the short-term changes after 5 and 56 weeks. The lubricants tested were an unused and used Mobil lubricant (0W/40; Exxon Mobil, Irving, TX, USA) and a biodegradable alternative (0W/20; Fuchs Lubricants, Harvey, IL, USA). Clean sediment was collected, contaminated with the lubricants, and deployed by divers onto the seabed in a randomized block design. The sampled sediments were analyzed by gas chromatography-flame-ionization detector and gas chromatography-mass spectrometry with selective ion monitoring. The base fluid of all lubricant treatments did not decrease significantly after 56 weeks in situ. Alkanoate esters of 1,1,1-tris(hydroxymethyl)propane in the biodegradable and unused lubricants were degraded extensively in situ; however, these esters constituted only a minor proportion of the lubricant volume. The additives, alkylated naphthalenes and substituted diphenylamines, were fairly resistant to degradation, which is of environmental concern because of their toxicity. The biodegradable lubricant did not break down to recognized biodegradable thresholds and, as such, should not be classified as biodegradable under Antarctic marine conditions. A separate experiment was conducted to determine the influence of sediment preparation and deployment on compound ratios within the lubricants, and we found that preparation and deployment of the contaminated sediments had only a minor effect on compound recovery. Further monitoring of this in situ experiment will provide much needed information about the long-term natural attenuation of lubricants.

Preparation and characterization of jackfruit seed starch/poly (vinyl alcohol) (PVA) blend film

NASA Astrophysics Data System (ADS)

Sarifuddin, N.; Shahrim, N. A.; Rani, N. N. S. A.; Zaki, H. H. M.; Azhar, A. Z. A.

2018-01-01

From the environmental point of view, biodegradable materials have been rapidly developed in the past years. PVA is one of the biodegradable synthetic polymers commonly used, but its degradation rate is slow. As an alternative to reduce plastic waste and accelerate the degradation process, PVA frequently blended with other natural polymers to improve its biodegradability. The natural polymer such as starch has high potential in enhancing PVA biodegradability by blending both components. The usage of starch extracted from agriculture wastes such as jackfruit seed is quite promising. In this study, jackfruit seed starch (JFSS)/poly (vinyl alcohol) (PVA) blend films were prepared using the solution casting method. The effect of starch content on the mechanical (tensile strength and elongation to break %) and physical properties of the tested films were investigated. The optimum tensile strength was obtained at 10.45 MPa when 4 wt. % of starch added to the blend. But, decreasing trend of tensile strength was found upon increasing the amount of starch beyond 4 wt. % in starch/PVA blend films. Nevertheless, elongation at break decreases with the increase in starch content. The mechanical properties of the blend films are supported by the Field Emission Scanning Electron Microscopy (FESEM), in which the native JFSS granules are wetted by PVA continuous phase with good dispersion and less agglomeration. The incorporation of JFSS in PVA has also resulted in the appearance of hydrogen bond peak, which evidenced by Fourier Transform Infrared (FTIR). Additionally, the biodegradation rate of JFSS/PVA was evaluated through soil burial test.

The Deep-Sea Microbial Community from the Amazonian Basin Associated with Oil Degradation.

PubMed

Campeão, Mariana E; Reis, Luciana; Leomil, Luciana; de Oliveira, Louisi; Otsuki, Koko; Gardinali, Piero; Pelz, Oliver; Valle, Rogerio; Thompson, Fabiano L; Thompson, Cristiane C

2017-01-01

One consequence of oil production is the possibility of unplanned accidental oil spills; therefore, it is important to evaluate the potential of indigenous microorganisms (both prokaryotes and eukaryotes) from different oceanic basins to degrade oil. The aim of this study was to characterize the microbial response during the biodegradation process of Brazilian crude oil, both with and without the addition of the dispersant Corexit 9500, using deep-sea water samples from the Amazon equatorial margin basins, Foz do Amazonas and Barreirinhas, in the dark and at low temperatures (4°C). We collected deep-sea samples in the field (about 2570 m below the sea surface), transported the samples back to the laboratory under controlled environmental conditions (5°C in the dark) and subsequently performed two laboratory biodegradation experiments that used metagenomics supported by classical microbiological methods and chemical analysis to elucidate both taxonomic and functional microbial diversity. We also analyzed several physical-chemical and biological parameters related to oil biodegradation. The concomitant depletion of dissolved oxygen levels, oil droplet density characteristic to oil biodegradation, and BTEX concentration with an increase in microbial counts revealed that oil can be degraded by the autochthonous deep-sea microbial communities. Indigenous bacteria (e.g., Alteromonadaceae, Colwelliaceae , and Alcanivoracaceae ), archaea (e.g., Halobacteriaceae, Desulfurococcaceae , and Methanobacteriaceae ), and eukaryotic microbes (e.g., Microsporidia, Ascomycota, and Basidiomycota) from the Amazonian margin deep-sea water were involved in biodegradation of Brazilian crude oil within less than 48-days in both treatments, with and without dispersant, possibly transforming oil into microbial biomass that may fuel the marine food web.

The Deep-Sea Microbial Community from the Amazonian Basin Associated with Oil Degradation

PubMed Central

Campeão, Mariana E.; Reis, Luciana; Leomil, Luciana; de Oliveira, Louisi; Otsuki, Koko; Gardinali, Piero; Pelz, Oliver; Valle, Rogerio; Thompson, Fabiano L.; Thompson, Cristiane C.

2017-01-01

One consequence of oil production is the possibility of unplanned accidental oil spills; therefore, it is important to evaluate the potential of indigenous microorganisms (both prokaryotes and eukaryotes) from different oceanic basins to degrade oil. The aim of this study was to characterize the microbial response during the biodegradation process of Brazilian crude oil, both with and without the addition of the dispersant Corexit 9500, using deep-sea water samples from the Amazon equatorial margin basins, Foz do Amazonas and Barreirinhas, in the dark and at low temperatures (4°C). We collected deep-sea samples in the field (about 2570 m below the sea surface), transported the samples back to the laboratory under controlled environmental conditions (5°C in the dark) and subsequently performed two laboratory biodegradation experiments that used metagenomics supported by classical microbiological methods and chemical analysis to elucidate both taxonomic and functional microbial diversity. We also analyzed several physical–chemical and biological parameters related to oil biodegradation. The concomitant depletion of dissolved oxygen levels, oil droplet density characteristic to oil biodegradation, and BTEX concentration with an increase in microbial counts revealed that oil can be degraded by the autochthonous deep-sea microbial communities. Indigenous bacteria (e.g., Alteromonadaceae, Colwelliaceae, and Alcanivoracaceae), archaea (e.g., Halobacteriaceae, Desulfurococcaceae, and Methanobacteriaceae), and eukaryotic microbes (e.g., Microsporidia, Ascomycota, and Basidiomycota) from the Amazonian margin deep-sea water were involved in biodegradation of Brazilian crude oil within less than 48-days in both treatments, with and without dispersant, possibly transforming oil into microbial biomass that may fuel the marine food web. PMID:28659874

Use of dynamic simulation to assess the behaviour of linear alkyl benzene sulfonates and their biodegradation intermediates (sulfophenylcarboxylic acids) in estuaries

NASA Astrophysics Data System (ADS)

García-Luque, E.; González-Mazo, E.; Forja, J. M.; Gómez-Parra, A.

2009-02-01

Dynamic laboratory simulation of processes affecting chemical species in their transit through estuaries is a very useful tool to characterize these littoral systems. To date, laboratory studies concerning biodegradation and sorption (onto suspended particulate matter) of LAS in an estuary are scarce. For this reason, a dynamic automated estuarine simulator has been employed to carry out different experiments in order to assess the biodegradability of linear alkyl benzene sulfonates (LAS) and their biodegradation intermediates (sulfophenylcarboxylic acids, SPCs) using environmentally representative LAS concentrations in estuaries by a continuous injection of LAS into the system. During the experiments, a great affinity of LAS for the solid phase has been found, as well as an increased adsorption in line with increased chain length. On the other hand, the presence of SPCs with chain length between 6 and 13 carbon atoms was detected. Accumulation and persistence of medium chain length SPCs (C 6-C 8) along the experiments show that their degradation constitutes the limiting step for the process of LAS mineralization. In the final zone of the simulated estuarine system, the levels of SPCs were below the limits of detection. Thus, the disappearance of SPCs indicated that LAS biodegradation had been completed along the estuary. Similar results have been described for different Iberian littoral ecosystems. Therefore, the simulator employed in this research appears to be a useful tool to anticipate the behaviour of a xenobiotic chemical in its transit through littoral systems with different salinity gradients.

Biodegradation kinetics for pesticide exposure assessment.

PubMed

Wolt, J D; Nelson, H P; Cleveland, C B; van Wesenbeeck, I J

2001-01-01

Understanding pesticide risks requires characterizing pesticide exposure within the environment in a manner that can be broadly generalized across widely varied conditions of use. The coupled processes of sorption and soil degradation are especially important for understanding the potential environmental exposure of pesticides. The data obtained from degradation studies are inherently variable and, when limited in extent, lend uncertainty to exposure characterization and risk assessment. Pesticide decline in soils reflects dynamically coupled processes of sorption and degradation that add complexity to the treatment of soil biodegradation data from a kinetic perspective. Additional complexity arises from study design limitations that may not fully account for the decline in microbial activity of test systems, or that may be inadequate for considerations of all potential dissipation routes for a given pesticide. Accordingly, kinetic treatment of data must accommodate a variety of differing approaches starting with very simple assumptions as to reaction dynamics and extending to more involved treatments if warranted by the available experimental data. Selection of the appropriate kinetic model to describe pesticide degradation should rely on statistical evaluation of the data fit to ensure that the models used are not overparameterized. Recognizing the effects of experimental conditions and methods for kinetic treatment of degradation data is critical for making appropriate comparisons among pesticide biodegradation data sets. Assessment of variability in soil half-life among soils is uncertain because for many pesticides the data on soil degradation rate are limited to one or two soils. Reasonable upper-bound estimates of soil half-life are necessary in risk assessment so that estimated environmental concentrations can be developed from exposure models. Thus, an understanding of the variable and uncertain distribution of soil half-lives in the environment is necessary to estimate bounding values. Statistical evaluation of measures of central tendency for multisoil kinetic studies shows that geometric means better represent the distribution in soil half-lives than do the arithmetic or harmonic means. Estimates of upper-bound soil half-life values based on the upper 90% confidence bound on the geometric mean tend to accurately represent the upper bound when pesticide degradation rate is biologically driven but appear to overestimate the upper bound when there is extensive coupling of biodegradation with sorptive processes. The limited data available comparing distribution in pesticide soil half-lives between multisoil laboratory studies and multilocation field studies suggest that the probability density functions are similar. Thus, upper-bound estimates of pesticide half-life determined from laboratory studies conservatively represent pesticide biodegradation in the field environment for the purposes of exposure and risk assessment. International guidelines and approaches used for interpretations of soil biodegradation reflect many common elements, but differ in how the source and nature of variability in soil kinetic data are considered. Harmonization of approaches for the use of soil biodegradation data will improve the interpretative power of these data for the purposes of exposure and risk assessment.

Assessing the role of Pseudomonas aeruginosa surface-active gene expression in hexadecane biodegradation in sand.

PubMed

Holden, P A; LaMontagne, M G; Bruce, A K; Miller, W G; Lindow, S E

2002-05-01

Low pollutant substrate bioavailability limits hydrocarbon biodegradation in soils. Bacterially produced surface-active compounds, such as rhamnolipid biosurfactant and the PA bioemulsifying protein produced by Pseudomonas aeruginosa, can improve bioavailability and biodegradation in liquid culture, but their production and roles in soils are unknown. In this study, we asked if the genes for surface-active compounds are expressed in unsaturated porous media contaminated with hexadecane. Furthermore, if expression does occur, is biodegradation enhanced? To detect expression of genes for surface-active compounds, we fused the gfp reporter gene either to the promoter region of pra, which encodes for the emulsifying PA protein, or to the promoter of the transcriptional activator rhlR. We assessed green fluorescent protein (GFP) production conferred by these gene fusions in P. aeruginosa PG201. GFP was produced in sand culture, indicating that the rhlR and pra genes are both transcribed in unsaturated porous media. Confocal laser scanning microscopy of liquid drops revealed that gfp expression was localized at the hexadecane-water interface. Wild-type PG201 and its mutants that are deficient in either PA protein, rhamnolipid synthesis, or both were studied to determine if the genetic potential to make surface-active compounds confers an advantage to P. aeruginosa biodegrading hexadecane in sand. Hexadecane depletion rates and carbon utilization efficiency in sand culture were the same for wild-type and mutant strains, i.e., whether PG201 was proficient or deficient in surfactant or emulsifier production. Environmental scanning electron microscopy revealed that colonization of sand grains was sparse, with cells in small monolayer clusters instead of multilayered biofilms. Our findings suggest that P. aeruginosa likely produces surface-active compounds in sand culture. However, the ability to produce surface-active compounds did not enhance biodegradation in sand culture because well-distributed cells and well-distributed hexadecane favored direct contact to hexadecane for most cells. In contrast, surface-active compounds enable bacteria in liquid culture to adhere to the hexadecane-water interface when they otherwise would not, and thus production of surface-active compounds is an advantage for hexadecane biodegradation in well-dispersed liquid systems.

Bioplastics science from a policy vantage point.

PubMed

Philp, Jim C; Bartsev, Alexandre; Ritchie, Rachael J; Baucher, Marie-Ange; Guy, K

2013-09-25

Society is fundamentally ambivalent to the use of plastics. On the one hand, plastics are uniquely flexible materials that have seen them occupy a huge range of functions, from simple packing materials to complex engineering components. On the other hand, their durability has raised concerns about their end-of-life disposal. When that disposal route is landfill, their invulnerability to microbial decomposition, combined with relatively low density and high bulk, means that plastics will occupy increasing amounts of landfill space in a world where available suitable landfill sites is shrinking. The search for biodegradable plastics and their introduction to the marketplace would appear to be a suitable amelioration strategy for such a problem. And yet the uptake of biodegradable plastics has been slow. The term biodegradable itself has entered public controversy, with accidental and intended misuse of the term; the intended misuse has led to accusations and instances of 'greenwashing'. For this and other reasons standards for biodegradability and compostability testing of plastics have been sought. An environmental dilemma with more far-reaching implications is climate change. The need for rapid and deep greenhouse gas (GHG) emissions cuts is one of the drivers for the resurgence of industrial biotechnology generally, and the search for bio-based plastics more specifically. Bio-based has come to mean plastics based on renewable resources, but this need not necessarily imply biodegradability. If the primary purpose is GHG emissions savings, then once again plastics durability can be a virtue, if the end-of-life solution can be energy recovery during incineration or recycling. The pattern of production is shifting from the true biodegradable plastics to the bio-based plastics, and that trend is likely to persist into the future. This paper looks at aspects of the science of biodegradable and bio-based plastics from the perspective of policy advisers and makers. It is often said that the bioplastics suffer from a lack of a favourable policy regime when compared to the wide-ranging set of policy instruments that are available on both the supply and demand side of biofuels production. Some possible policy measures are discussed. Copyright © 2012 Elsevier B.V. All rights reserved.

Mechanical-biological treatment: performance and potentials. An LCA of 8 MBT plants including waste characterization.

PubMed

Montejo, Cristina; Tonini, Davide; Márquez, María del Carmen; Astrup, Thomas Fruergaard

2013-10-15

In the endeavour of avoiding presence of biodegradable waste in landfills and increasing recycling, mechanical-biological treatment (MBT) plants have seen a significant increase in number and capacity in the last two decades. The aim of these plants is separating and stabilizing the quickly biodegradable fraction of the waste as well as recovering recyclables from mixed waste streams. In this study the environmental performance of eight MBT-based waste management scenarios in Spain was assessed by means of life cycle assessment. The focus was on the technical and environmental performance of the MBT plants. These widely differed in type of biological treatment and recovery efficiencies. The results indicated that the performance is strongly connected with energy and materials recovery efficiency. The recommendation for upgrading and/or commissioning of future plants is to optimize materials recovery through increased automation of the selection and to prioritize biogas-electricity production from the organic fraction over direct composting. The optimal strategy for refuse derived fuel (RDF) management depends upon the environmental compartment to be prioritized and the type of marginal electricity source in the system. It was estimated that, overall, up to ca. 180-190 kt CO2-eq. y(-1) may be saved by optimizing the MBT plants under assessment. Copyright © 2013 Elsevier Ltd. All rights reserved.

Biological Remediation of Petroleum Contaminants

NASA Astrophysics Data System (ADS)

Kuhad, Ramesh Chander; Gupta, Rishi

Large volumes of hazardous wastes are generated in the form of oily sludges and contaminated soils during crude oil transportation and processing. Although many physical, chemical and biological treatment technologies are available for petroleum contaminants petroleum contaminants in soil, biological methods have been considered the most cost-effective. Practical biological remediation methods typically involve direct use of the microbes naturally occurring in the contaminated environment and/or cultured indigenous or modified microorganisms. Environmental and nutritional factors, including the properties of the soil, the chemical structure of the hydrocarbon(s), oxygen, water, nutrient availability, pH, temperature, and contaminant bioavailability, can significantly affect the rate and the extent of hydrocarbon biodegradation hydrocarbon biodegradation by microorganisms in contaminated soils. This chapter concisely discusses the major aspects of bioremediation of petroleum contaminants.

Polysaccharide-Based Membranes in Food Packaging Applications.

PubMed

Ferreira, Ana R V; Alves, Vítor D; Coelhoso, Isabel M

2016-04-13

Plastic packaging is essential nowadays. However, the huge environmental problem caused by landfill disposal of non-biodegradable polymers in the end of life has to be minimized and preferentially eliminated. The solution may rely on the use of biopolymers, in particular polysaccharides. These macromolecules with film-forming properties are able to produce attracting biodegradable materials, possibly applicable in food packaging. Despite all advantages of using polysaccharides obtained from different sources, some drawbacks, mostly related to their low resistance to water, mechanical performance and price, have hindered their wider use and commercialization. Nevertheless, with increasing attention and research on this field, it has been possible to trace some strategies to overcome the problems and recognize solutions. This review summarizes some of the most used polysaccharides in food packaging applications.

Environmentally safe fluids for hydraulics used in civil engineering

DOE Office of Scientific and Technical Information (OSTI.GOV)

Wirzberger, E.; Rexroth, M.

1995-12-31

The majority of hydraulic units used in civil engineering are operated with pressure fluids based on mineral oil. Most civil engineering projects are installed near or immediately next to bodies of water, therefore, any leakage signifies danger for the environment. We try to avert this danger with increasingly safe hydraulic drives. However, growing environmental awareness and stricter laws are demanding more and more environmentally safe hydraulic fluids. Today, the manufacturers of fluids and hydraulic drives have to accept this challenge. What exactly is an environmentally safe hydraulic fluid? The major objectives are: (1) they have to be biodegradable, (2) nomore » fish toxicity, (3) no water pollution, and (4) food compatibility.« less

Enhanced biodegradation of mixed PAHs by mutated naphthalene 1,2-dioxygenase encoded by Pseudomonas putida strain KD6 isolated from petroleum refinery waste.

PubMed

Dutta, Kunal; Shityakov, Sergey; Das, Prangya P; Ghosh, Chandradipa

2017-12-01

Polycyclic aromatic hydrocarbons (PAHs) are a group of environmental pollutant that are given top priority to maintain water and soil quality to the most amenable standard. Biodegradation of PAHs by bacteria is the convenient option for decontamination on site or off site. The aim of the present study was to isolate and identify naturally occurring bacteria having mixed PAHs biodegradation ability. The newly isolated Pseudomonas putida strain KD6 was found to efficiently degrade 97.729% of 1500 mg L -1 mixed PAHs within 12 days in carbon-deficient minimal medium (CSM). The half-life ( t 1/2 ) and degradation rate constant ( k ) were estimated to be 3.2 and 0.2165 days, respectively. The first-order kinetic parameters in soil by strain KD6 had shown efficient biodegradation potency with the higher concentration of total PAHs (1500 mg kg -1 soil), t 1/2  = 10.44 days -1 . However, the biodegradation by un-inoculated control soil was found slower ( t 1/2  = 140 days -1 ) than the soil inoculated with P. putida strain KD6. The enzyme kinetic constants are also in agreement with chemical data obtained from the HPLC analysis. In addition, the sequence analysis and molecular docking studies showed that the strain KD6 encodes a mutant version of naphthalene 1,2-dioxygenase which have better Benzpyrene binding energy (-9.90 kcal mol -1 ) than wild type (-8.18 kcal mol -1 ) enzyme (chain A, 1NDO), respectively, with 0.00 and 0.08 RMSD values. The mutated naphthalene 1,2-dioxygenase nah Ac has six altered amino acid residues near to the ligand binding site. The strain KD6 could be a good bioresource for in situ or ex situ biodegradation of polycyclic aromatic hydrocarbon.

Characterization of Polyhydroxyalkanoate Produced by Bacillus megaterium VB89 Isolated from Nisargruna Biogas Plant.

PubMed

Baikar, Vishakha; Rane, Ashwini; Deopurkar, Rajendra

2017-09-01

Polyhydroxyalkanoates (PHAs) are naturally occurring biodegradable polymers that can curb the extensive use of polypropylene based plastics. In contrast to chemically synthesized polypropylene plastics, PHAs are biodegradable and thus environmentally safe. PHAs have attracted much attention as biocompatible and biodegradable thermoplastics. The present study involves isolation of bacteria from different environments capable of synthesizing PHAs. The bacterium producing highest yield of PHA (0.672 ± 0.041 g/L) was identified as Bacillus megaterium VB89 by biochemical and molecular techniques such as 16S rDNA sequence analysis. Strain VB89 produced polyhydroxybutyrate (PHB) as revealed by FTIR and NMR. This PHB had an average molecular weight of 2.89 × 10 5  Da and a polydispersity index of 2.37. Thermal properties of the PHB included a glass transition temperature of 13.97 °C, a melting temperature of 181.74 °C, and a decomposition temperature of 234 °C. All these properties indicated that VB89 produced PHB of high purity and good thermal stability.

A new class of bio-heat resisted polymer blend.

NASA Astrophysics Data System (ADS)

Pack, Seongchan; Kashiwagi, Takashi; Koga, Tadanori; Rafailovich, Miriam

2009-03-01

Increasing in oil prices and environmental concerns is a driving force to seek out alternative materials. A completely biodegradable starch is a candidate for the alternative materials. Since the starch is brittle, it must be mixed with other polymers. In order to make a thermoplastic starch (TPS), we need a bio-compatiblizer to increase a degree of compatibilization. The biocompatibilzer can be a small molecules or nanoparticles with the small molecules, which leads to improved material properties. In order to demonstrate a possible biocompatibilzer, we first developed a corn-based starch impregnated with non-halogenated flame retardant formulations. The starch was blended with Ecoflex, a biodegradable polymer. Using SAXS and USAXS we characterized structures of the compounds with different amount of Ecoflex by weight. Furthermore, the addition of 5% nanoparticles in the compounds increased the Young's Modulus and impact toughness significantly. The compounds also did flame test. It is indicated that the compound with the addition of the nanopaticles would pass with a UL-94V0 rating. Therefore, the procedure for producing these TPS compounds can be applied to any biodegradable polymers, manufacturing a new bio-heat resisted compound.

Effect of redox conditions on MTBE biodegradation in surface water Sediments

USGS Publications Warehouse

Bradley, P.M.; Chapelle, F.H.; Landmeyer, J.E.

2001-01-01

Microbial degradation of methyl tert-butyl ether (MTBE) was observed in surface water-sediment microcosms under anaerobic conditions. The efficiency and products of anaerobic MTBE biodegradation were dependent on the predominant terminal electron-accepting conditions. In the presence of substantial methanogenic activity, MTBE biodegradation was nominal and involved reduction of MTBE to the toxic product, tert-butyl alcohol (TBA). In the absence of significant methanogenic activity, accumulation of [14C]TBA generally decreased, and mineralization of [U-14C]MTBE to 14CO2 generally increased as the oxidative potential of the predominant terminal electron acceptor increased in the order of SO4, Fe(III), Mn(IV) < NO3 < O2. Microbial mineralization of MTBE to CO2 under Mn(IV)or SO4-reducing conditions has not been reported previously. The results of this study indicate that microorganisms inhabiting the sediments of streams and lakes can degrade MTBE effectively under a range of anaerobic terminal electron-accepting conditions. Thus, anaerobic bed sediment microbial processes may provide a significant environmental sink for MTBE in surface water systems throughout the United States.

Biofiltration kinetics for volatile organic compounds (VOCs) and development of a structure-biodegradability relationship

DOE Office of Scientific and Technical Information (OSTI.GOV)

Govind, R.; Wang, Z.; Bishop, D.F.

1997-12-31

In recent years, regulation of hazardous air pollutants under the Clean Air Act and its amendments, has emerged as a major environmental issue. Major sources of volatile organic compounds (VOCs) in air are chemical production plants, manufacturing sites using common solvents, combustion sources, and waste treatment operations, such as waste water treatment plants, vacuum extraction of contaminated soils, and ground water stripping operations. Biofiltration is an emerging technology for treatment of biodegradable volatile organic compounds (VOCs) present in air. In biofiltration, the contaminants are contacted with active microorganisms present either in naturally bioactive materials, such as soil, peat, compost, etc.,more » or immobilized on an inactive support media. Design of biofilters requires information on biodegradation kinetics which controls biofilter size. In this paper, an experimental microbiofilter system is presented which can be used to measure biofiltration kinetics for any volatile organic compound. A mathematical model is used to derive the Monod biokinetic parameters from the experimental data. Finally, a structure-bioactivity relationship is derived for estimating the biofiltration biokinetic parameters for a variety of VOCs.« less

The effect of operational parameters on the biodegradation of bisphenols by Trametes versicolor laccase immobilized on Hippospongia communis spongin scaffolds.

PubMed

Zdarta, Jakub; Antecka, Katarzyna; Frankowski, Robert; Zgoła-Grześkowiak, Agnieszka; Ehrlich, Hermann; Jesionowski, Teofil

2018-02-15

Due to the rapid growth in quantities of phenolic compounds in wastewater, the development of efficient and environmentally friendly methods for their removal becomes a necessity. Thus, in a presented work, for the first time, a novel material, Hippospongia communis spongin-based scaffold, was used as a biopolymeric support for the immobilization of laccase from Trametes versicolor. The resulting biocatalytic systems were used for the biodegradation of three bisphenols: bisphenol A (BPA), bisphenol F (BPF) and bioremoval-resistant bisphenol S (BPS). Optimization of the immobilization and biodegradation methodologies was performed to increase bisphenols removal. The effect of temperature, pH and initial pollutant concentration was evaluated. It was shown that under optimal conditions, almost 100% of BPA (pH5, 30°C) and BPF (pH5, 40°C), and over 40% of BPS (pH4, 30°C) was removed from the solution at a concentration of 2mg/mL. Furthermore, the immobilized laccase exhibited good reusability and storage stability, retaining over 80% of its initial activity after 50days of storage. In addition, the main biodegradation products of BPA and BPF were identified. It was shown that mainly dimers and trimers were formed following the oxidation of bisphenols by the immobilized laccase. Copyright © 2017 Elsevier B.V. All rights reserved.

Biodegradation of diesel fuel by a microbial consortium in the presence of 1-alkoxymethyl-2-methyl-5-hydroxypyridinium chloride homologues.

PubMed

Chrzanowski, Lukasz; Stasiewicz, Monika; Owsianiak, Mikołaj; Szulc, Alicja; Piotrowska-Cyplik, Agnieszka; Olejnik-Schmidt, Agnieszka K; Wyrwas, Bogdan

2009-09-01

Fast development of ionic liquids as gaining more and more attention valuable chemicals will undoubtedly lead to environmental pollution. New formulations and application of ionic liquids may result in contamination in the presence of hydrophobic compounds, such as petroleum mixtures. We hypothesize that in the presence of diesel fuel low-water-soluble ionic liquids may become more toxic to hydrocarbon-degrading microorganisms. In this study the influence of 1-alkoxymethyl-2-methyl-5-hydroxypyridinium chloride homologues (side-chain length from C(3) to C(18)) on biodegradation of diesel fuel by a bacterial consortium was investigated. Whereas test performed for the consortium cultivated on disodium succinate showed that toxicity of the investigated ionic liquids decreased with increase in side-chain length, only higher homologues (C(8)-C(18)) caused a decrease in diesel fuel biodegradation. As a result of exposure to toxic compounds also modification in cell surface hydrophobicity was observed (MATH). Disulphine blue active substances method was employed to determine partitioning index of ionic liquids between water and diesel fuel phase, which varied from 1.1 to 51% for C(3) and C(18) homologues, respectively. We conclude that in the presence of hydrocarbons acting as a solvent, the increased bioavailability of hydrophobic homologues is responsible for the decrease in biodegradation efficiency of diesel fuel.

Biodegradable and Petroleum-Based Microplastics Do Not Differ in Their Ingestion and Excretion but in Their Biological Effects in a Freshwater Invertebrate Gammarus fossarum

PubMed Central

Straub, Sandrine; Hirsch, Philipp E.; Burkhardt-Holm, Patricia

2017-01-01

Research on the uptake and effects of bioplastics by aquatic organisms is still in its infancy. Here, we aim to advance the field by comparing uptake and effects of microplastic particles (MPP) of a biodegradable bioMPP (polyhydroxybutyrate (PHB)) and petroleum-based MPP (polymethylmethacrylate (PMMA)) in the freshwater amphipod Gammarus fossarum. Ingestion of both MPP in different particle sizes (32–250 µm) occurred after 24 h, with highest ingestion of particles in the range 32–63 µm and almost complete egestion after 64 h. A four-week effect-experiment showed a significant decrease of the assimilation efficiency in amphipods exposed to the petroleum-based MPP from week two onwards. The petroleum-based PMMA affected assimilation efficiency significantly in contrast to the biodegradable PHB, but overall differences in direct comparison of MPP types were small. Both MPP types led to a significantly lower wet weight gain relative to the control treatments. After four weeks, differences between both MPP types and silica, used as a natural particle control, were detected. In summary, these results suggest that both MPP types provoke digestive constraints on the amphipods, which go beyond those of natural non-palatable particles. This highlights the need for more detailed research comparing environmental effects of biodegradable and petroleum-based MPP and testing those against naturally occurring particle loads. PMID:28703776

Aerobic biodegradation potential of endocrine-disrupting chemicals in surface-water sediment at Rocky Mountain National Park, USA.

PubMed

Bradley, Paul M; Battaglin, William A; Iwanowicz, Luke R; Clark, Jimmy M; Journey, Celeste A

2016-05-01

Endocrine-disrupting chemicals (EDCs) in surface water and bed sediment threaten the structure and function of aquatic ecosystems. In natural, remote, and protected surface-water environments where contaminant releases are sporadic, contaminant biodegradation is a fundamental driver of exposure concentration, timing, duration, and, thus, EDC ecological risk. Anthropogenic contaminants, including known and suspected EDCs, were detected in surface water and sediment collected from 2 streams and 2 lakes in Rocky Mountain National Park (Colorado, USA). The potential for aerobic EDC biodegradation was assessed in collected sediments using 6 (14) C-radiolabeled model compounds. Aerobic microbial mineralization of natural (estrone and 17β-estradiol) and synthetic (17α-ethinylestradiol) estrogen was significant at all sites. Bed sediment microbial communities in Rocky Mountain National Park also effectively degraded the xenoestrogens bisphenol-A and 4-nonylphenol. The same sediment samples exhibited little potential for aerobic biodegradation of triclocarban, however, illustrating the need to assess a wider range of contaminant compounds. The present study's results support recent concerns over the widespread environmental occurrence of carbanalide antibacterials, like triclocarban and triclosan, and suggest that backcountry use of products containing these compounds should be discouraged. Published 2015 Wiley Periodicals Inc. on behalf of SETAC. This article is a US Government work and, as such, is in the public domain in the United States of America.

A sustainable slashing industry using biodegradable sizes from modified soy protein to replace petro-based poly(vinyl alcohol).

PubMed

Zhao, Yi; Zhao, Yuzhu; Xu, Helan; Yang, Yiqi

2015-02-17

Biodegradable sizing agents from triethanolamine (TEA) modified soy protein could substitute poly(vinyl alcohol)(PVA) sizes for high-speed weaving of polyester and polyester/cotton yarns to substantially decrease environmental pollution and impel sustainability of textile industry. Nonbiodegradable PVA sizes are widely used and mainly contribute to high chemical oxygen demand (COD) in textile effluents. It has not been possible to effectively degrade, reuse or replace PVA sizes so far. Soy protein with good biodegradability showed potential as warp sizes in our previous studies. However, soy protein sizes lacked film flexibility and adhesion for required high-speed weaving. Additives with multiple hydroxyl groups, nonlinear molecule, and electric charge could physically modify secondary structure of soy protein and lead to about 23.6% and 43.3% improvement in size adhesion and ability of hair coverage comparing to unmodified soy protein. Industrial weaving results showed TEA-soy protein had relative weaving efficiency 3% and 10% higher than PVA and chemically modified starch sizes on polyester/cotton fabrics, and had relative weaving efficiency similar to PVA on polyester fabrics, although with 3- 6% lower add-on. In addition, TEA-soy sizes had a BOD5/COD ratio of 0.44, much higher than 0.03 for PVA, indicating that TEA-soy sizes were easily biodegradable in activated sludge.

Review of concrete biodeterioration in relation to nuclear waste.

PubMed

Turick, Charles E; Berry, Christopher J

2016-01-01

Storage of radioactive waste in concrete structures is a means of containing wastes and related radionuclides generated from nuclear operations in many countries. Previous efforts related to microbial impacts on concrete structures that are used to contain radioactive waste showed that microbial activity can play a significant role in the process of concrete degradation and ultimately structural deterioration. This literature review examines the research in this field and is focused on specific parameters that are applicable to modeling and prediction of the fate of concrete structures used to store or dispose of radioactive waste. Rates of concrete biodegradation vary with the environmental conditions, illustrating a need to understand the bioavailability of key compounds involved in microbial activity. Specific parameters require pH and osmotic pressure to be within a certain range to allow for microbial growth as well as the availability and abundance of energy sources such as components involved in sulfur, iron and nitrogen oxidation. Carbon flow and availability are also factors to consider in predicting concrete biodegradation. The microbial contribution to degradation of the concrete structures containing radioactive waste is a constant possibility. The rate and degree of concrete biodegradation is dependent on numerous physical, chemical and biological parameters. Parameters to focus on for modeling activities and possible options for mitigation that would minimize concrete biodegradation are discussed and include key conditions that drive microbial activity on concrete surfaces. Copyright © 2015. Published by Elsevier Ltd.

Biodegradation test of SPS-LS blends as polymer electrolyte membrane fuel cells

DOE Office of Scientific and Technical Information (OSTI.GOV)

Putri, Zufira, E-mail: zufira.putri@gmail.com, E-mail: arcana@chem.itb.ac.id; Arcana, I Made, E-mail: zufira.putri@gmail.com, E-mail: arcana@chem.itb.ac.id

Sulfonated polystyrene (SPS) can be applied as a proton exchange membrane fuel cell due to its fairly good chemical stability. In order to be applied as polymer electrolyte membrane fuel cells (PEMFCs), membrane polymer should have a good ionic conductivity, high proton conductivity, and high mechanical strength. Lignosulfonate (LS) is a complex biopolymer which has crosslinks and sulfonate groups. SPS-LS blends with addition of SiO{sub 2} are used to increase the proton conductivity and to improve the mechanical properties and thermal stability. However, the biodegradation test of SPS-LS blends is required to determine whether the application of these membranes tomore » be applied as an environmentally friendly membrane. In this study, had been done the synthesis of SPS, biodegradability test of SPS-LS blends with variations of LS and SiO{sub 2} compositions. The biodegradation test was carried out in solid medium of Luria Bertani (LB) with an activated sludge used as a source of microorganism at incubation temperature of 37°C. Based on the results obtained indicated that SPS-LS-SiO{sub 2} blends are more decomposed by microorganism than SPS-LS blends. This result is supported by analysis of weight reduction percentage, functional groups with Fourier Transform Infrared (FTIR) Spectroscopy, and morphological surface with Scanning Electron Microscopy (SEM)« less

Biomimetic microenvironment complexity to redress the balance between biodegradation and de novo matrix synthesis during early phase of vascular tissue engineering.

PubMed

Vatankhah, Elham; Prabhakaran, Molamma P; Ramakrishna, Seeram

2017-12-01

Physiological functionality of a tissue engineered vascular construct depends on the phenotype of smooth muscle cells (SMCs) cultured into the scaffold and mechanical robust of the construct relies on two simultaneous mechanisms including scaffold biodegradation and de novo matrix synthesis by SMCs which both can be influenced by scaffold properties and culture condition. Our focus in this study was to provide an appropriate environmental condition within tissue engineering context to meet foregoing requisites for a successful vascular regeneration. To this end, SMCs seeded onto electrospun Tecophilic/gelatin (TP(70)/gel(30)) scaffolds were subjected to orbital shear stress. Given the improvement in mechanical properties of dynamically stimulated cell-seeded constructs after a span of 10days, effect of fluctuating shear stress on scaffold biodegradation and SMC behavior was investigated. Compared to static condition, SMCs proliferated more rapidly and concomitantly built up greater collagen content in response to dynamic culture, suggesting a reasonable balance between scaffold biodegradation and matrix turnover for maintaining the structural integrity and mechanical support to seeded cells during early phase of vascular tissue engineering. Despite higher proliferation of SMCs under dynamic condition, cells preserved nearly spindle like morphology and contractile protein expression likely thanks to composition of the scaffold. Copyright © 2017 Elsevier B.V. All rights reserved.

In vitro mutagenicity, NMR metabolite characterization of azo and triphenylmethanes dyes by adherents bacteria and the role of the "cna" adhesion gene in activated sludge.

PubMed

Ayed, Lamia; Bakir, Karima; Ben Mansour, Hedi; Hammami, Saousen; Cheref, Abdelkrim; Bakhrouf, Amina

2017-02-01

Staphylococcus aureus, showing the greatest decolorization ability, was further investigated for Methyl Red (MR) Congo Red (CR), Crystal Violet (CV) and Malachite Green (MG) decolorization using response surface methodology (RSM). The chemometric methods use, based on statistical design of experiments (DOEs) such as RSM is becoming increasingly widespread in several sciences such as analytical chemistry, engineering and environmental chemistry. Stapphylococcus aureus ATCC 25923, Stapphylococcus aureus (S1) and Stapphylococcus aureus (S2), were isolated from textile wastewater plant located in KsarHellal, Tunisia and were tested for their decolorization capacity. PCR technique was utilized to identify the 3 bacterial strains and to detect the adhesin gene "cna". Biodegradation of MR, CR, CV and MG (750 ppm), were investigated under shaking condition in Mineral Salt Medium (MSM) solution at pH 7.5 and temperature 30 °C, using a 3.7 × 10 5  CFU/ml as inoculum size. Our results showed that Staphylococcus aureus had a high decolorization capacity. Nuclear magnetic resonance (NMR) spectroscopy analysis confirmed the biodegradation of dyes. The four dyes mutagenicity with the S9 metabolizing system decreased significantly after biodegradation and totally disappeared. Nuclear magnetic resonance (NMR) spectroscopy analysis confirmed the biodegradation of dyes. Copyright © 2016 Elsevier Ltd. All rights reserved.

Evaluation of Municipal Wastewater Treatment Plant Activated Sludge for Biodegradation of Propylene Glycol as an Aircraft Deicing Fluid

DTIC Science & Technology

2012-03-01

Propylene Glycol Deicer Biodegredation Kinetics: Complete-Mix Stirred Tank Reactors , Filter, and Fluidized Bed . Journal of Environmental...scale sequencing batch reactor containing municipal waste water treatment facility activated sludge (AS) performing simultaneous organic carbon...Sequencing Batch Reactor Operation ..................................................................... 13 PG extraction from AS

Resistance: a threat to the insecticidal crystal proteins of Bacillus thuringiensis

Treesearch

Leah S. Bauer

1995-01-01

Insecticidal crystal proteins (also known as d-endotoxins) synthesized by the bacterium Bacillus thuringiensis Berliner (Bt) are the active ingredient of various environmentally friendly insecticides that are 1) highly compatible with natural enemies and other nontarget organisms due to narrow host specificity, 2) harmless to vertebrates, 3) biodegradable in the...

Green materials prepared by using a green processing method: Plant oil-based polymers prepared in CO2 medium with mild conditions

USDA-ARS?s Scientific Manuscript database

Recent efforts have been focused on the development of environmentally friendly replacements for volatile organic solvents. One promising candidate is supercritical carbon dioxide because of its low toxicity and no solvent residues in the final products. Renewed interest in biodegradable polymeric m...

Cycling Back to Nature with Biodegradable Polymers.

ERIC Educational Resources Information Center

Horton, Robert L.; And Others

This sourcebook, for use with groups of up to 25 young people ages 10 and up, is designed to stimulate a sense of environmental stewardship for the planet through group discussion, role playing, experimentation, demonstration, and simulation. Lessons that stand alone or can be used in sequence require common materials and little preparation,…

Trash--Our Only Growing Resource. Environmental Ecological Education Project.

ERIC Educational Resources Information Center

Giebelhausen, Maribeth R.; And Others

With the increases in population and technology, non-biodegradable materials like plastic, glass, and aluminum and waste disposal have become very real problems in out society. This unit, designed for seventh-grade students, focuses on the problems of waste disposal and examines the function of recycling, the role of the consumer in determining…

Chitosan-based water-propelled micromotors with strong antibacterial activity.

PubMed

Delezuk, Jorge A M; Ramírez-Herrera, Doris E; Esteban-Fernández de Ávila, Berta; Wang, Joseph

2017-02-09

A rapid and efficient micromotor-based bacteria killing strategy is described. The new antibacterial approach couples the attractive antibacterial properties of chitosan with the efficient water-powered propulsion of magnesium (Mg) micromotors. These Janus micromotors consist of Mg microparticles coated with the biodegradable and biocompatible polymers poly(lactic-co-glycolic acid) (PLGA), alginate (Alg) and chitosan (Chi), with the latter responsible for the antibacterial properties of the micromotor. The distinct speed and efficiency advantages of the new micromotor-based environmentally friendly antibacterial approach have been demonstrated in various control experiments by treating drinking water contaminated with model Escherichia coli (E. coli) bacteria. The new dynamic antibacterial strategy offers dramatic improvements in the antibacterial efficiency, compared to static chitosan-coated microparticles (e.g., 27-fold enhancement), with a 96% killing efficiency within 10 min. Potential real-life applications of these chitosan-based micromotors for environmental remediation have been demonstrated by the efficient treatment of seawater and fresh water samples contaminated with unknown bacteria. Coupling the efficient water-driven propulsion of such biodegradable and biocompatible micromotors with the antibacterial properties of chitosan holds great considerable promise for advanced antimicrobial water treatment operation.

Relaxation Time Distribution (RTD) of Spectral Induced Polarization (SIP) data from environmental studies

NASA Astrophysics Data System (ADS)

Ntarlagiannis, D.; Ustra, A.; Slater, L. D.; Zhang, C.; Mendonça, C. A.

2015-12-01

In this work we present an alternative formulation of the Debye Decomposition (DD) of complex conductivity spectra, with a new set of parameters that are directly related to the continuous Debye relaxation model. The procedure determines the relaxation time distribution (RTD) and two frequency-independent parameters that modulate the induced polarization spectra. The distribution of relaxation times quantifies the contribution of each distinct relaxation process, which can in turn be associated with specific polarization processes and characterized in terms of electrochemical and interfacial parameters as derived from mechanistic models. Synthetic tests show that the procedure can successfully fit spectral induced polarization (SIP) data and accurately recover the RTD. The procedure was applied to different data sets, focusing on environmental applications. We focus on data of sand-clay mixtures artificially contaminated with toluene, and crude oil-contaminated sands experiencing biodegradation. The results identify characteristic relaxation times that can be associated with distinct polarization processes resulting from either the contaminant itself or transformations associated with biodegradation. The inversion results provide information regarding the relative strength and dominant relaxation time of these polarization processes.

Microbial populations in contaminant plumes

USGS Publications Warehouse

Haack, S.K.; Bekins, B.A.

2000-01-01

Efficient biodegradation of subsurface contaminants requires two elements: (1) microbial populations with the necessary degradative capabilities, and (2) favorable subsurface geochemical and hydrological conditions. Practical constraints on experimental design and interpretation in both the hydrogeological and microbiological sciences have resulted in limited knowledge of the interaction between hydrogeological and microbiological features of subsurface environments. These practical constraints include: (1) inconsistencies between the scales of investigation in the hydrogeological and microbiological sciences, and (2) practical limitations on the ability to accurately define microbial populations in environmental samples. However, advances in application of small-scale sampling methods and interdisciplinary approaches to site investigations are beginning to significantly improve understanding of hydrogeological and microbiological interactions. Likewise, culture-based and molecular analyses of microbial populations in subsurface contaminant plumes have revealed significant adaptation of microbial populations to plume environmental conditions. Results of recent studies suggest that variability in subsurface geochemical and hydrological conditions significantly influences subsurface microbial-community structure. Combined investigations of site conditions and microbial-community structure provide the knowledge needed to understand interactions between subsurface microbial populations, plume geochemistry, and contaminant biodegradation.

Stimulating soil microorganisms for mineralizing the herbicide isoproturon by means of microbial electroremediating cells.

PubMed

Rodrigo Quejigo, Jose; Dörfler, Ulrike; Schroll, Reiner; Esteve-Núñez, Abraham

2016-05-01

The absence of suitable terminal electron acceptors (TEA) in soil might limit the oxidative metabolism of environmental microbial populations. Microbial electroremediating cells (MERCs) consist in a variety of bioelectrochemical devices that aim to overcome electron acceptor limitation and maximize metabolic oxidation with the purpose of enhancing the biodegradation of a pollutant in the environment. The objective of this work was to use MERCs principles for stimulating soil bacteria to achieve the complete biodegradation of the herbicide (14) C-isoproturon (IPU) to (14) CO(2) in soils. Our study concludes that using electrodes at a positive potential [+600 mV (versus Ag/AgCl)] enhanced the mineralization by 20-fold respect the electrode-free control. We also report an overall profile of the (14) C-IPU metabolites and a (14) C mass balance in response to the different treatments. The remarkable impact of electrodes on the microbial activity of natural communities suggests a promising future for this emerging environmental technology that we propose to name bioelectroventing. © 2016 The Authors. Microbial Biotechnology published by John Wiley & Sons Ltd and Society for Applied Microbiology.

In silico models for predicting ready biodegradability under REACH: a comparative study.

PubMed

Pizzo, Fabiola; Lombardo, Anna; Manganaro, Alberto; Benfenati, Emilio

2013-10-01

REACH (Registration Evaluation Authorization and restriction of Chemicals) legislation is a new European law which aims to raise the human protection level and environmental health. Under REACH all chemicals manufactured or imported for more than one ton per year must be evaluated for their ready biodegradability. Ready biodegradability is also used as a screening test for persistent, bioaccumulative and toxic (PBT) substances. REACH encourages the use of non-testing methods such as QSAR (quantitative structure-activity relationship) models in order to save money and time and to reduce the number of animals used for scientific purposes. Some QSAR models are available for predicting ready biodegradability. We used a dataset of 722 compounds to test four models: VEGA, TOPKAT, BIOWIN 5 and 6 and START and compared their performance on the basis of the following parameters: accuracy, sensitivity, specificity and Matthew's correlation coefficient (MCC). Performance was analyzed from different points of view. The first calculation was done on the whole dataset and VEGA and TOPKAT gave the best accuracy (88% and 87% respectively). Then we considered the compounds inside and outside the training set: BIOWIN 6 and 5 gave the best results for accuracy (81%) outside training set. Another analysis examined the applicability domain (AD). VEGA had the highest value for compounds inside the AD for all the parameters taken into account. Finally, compounds outside the training set and in the AD of the models were considered to assess predictive ability. VEGA gave the best accuracy results (99%) for this group of chemicals. Generally, START model gave poor results. Since BIOWIN, TOPKAT and VEGA models performed well, they may be used to predict ready biodegradability. Copyright © 2013 Elsevier B.V. All rights reserved.

Comparison of ready biodegradation estimation methods for fragrance materials.

PubMed

Boethling, Robert

2014-11-01

Biodegradability is fundamental to the assessment of environmental exposure and risk from organic chemicals. Predictive models can be used to pursue both regulatory and chemical design (green chemistry) objectives, which are most effectively met when models are easy to use and available free of charge. The objective of this work was to evaluate no-cost estimation programs with respect to prediction of ready biodegradability. Fragrance materials, which are structurally diverse and have significant exposure potential, were used for this purpose. Using a database of 222 fragrance compounds with measured ready biodegradability, 10 models were compared on the basis of overall accuracy, sensitivity, specificity, and Matthews correlation coefficient (MCC), a measure of quality for binary classification. The 10 models were VEGA© Non-Interactive Client, START (Toxtree©), Biowin©1-6, and two models based on inductive machine learning. Applicability domain (AD) was also considered. Overall accuracy was ca. 70% and varied little over all models, but sensitivity, specificity and MCC showed wider variation. Based on MCC, the best models for fragrance compounds were Biowin6, VEGA and Biowin3. VEGA performance was slightly better for the <50% of the compounds it identified as having "high reliability" predictions (AD index >0.8). However, removing compounds with one and only one quaternary carbon yielded similar improvement in predictivity for VEGA, START, and Biowin3/6, with a smaller penalty in reduced coverage. Of the nine compounds for which the eight models (VEGA, START, Biowin1-6) all disagreed with the measured value, measured analog data were available for seven, and all supported the predicted value. VEGA, Biowin3 and Biowin6 are judged suitable for ready biodegradability screening of fragrance compounds. Published by Elsevier B.V.

Resistance to moist conditions of whey protein isolate and pea starch biodegradable films and low density polyethylene nondegradable films: a comparative study

NASA Astrophysics Data System (ADS)

Mehyar, G. F.; Bawab, A. Al

2015-10-01

Biodegradable packaging materials are degraded under the natural environmental conditions. Therefore using them could alleviate the problem of plastics accumulation in nature. For effective replacement of plastics, with biodegradable materials, biodegradable packages should keep their properties under the high relative humidity (RH) conditions. Therefore the objectives of the study were to develop biodegradable packaging material based on whey protein isolate (WPI) and pea starch (PS). To study their mechanical, oxygen barrier and solubility properties under different RHs compared with those of low density polyethylene (LDPE), the most used plastic in packaging. Films of WPI and PS were prepared separately and conditioned at different RH (30-90%) then their properties were studied. At low RHs (<50%), WPI films had 2-3 times lower elongation at break (E or stretchability) than PS and LDPE. Increasing RH to 90% significantly (P<0.01) increased the elongation of PS but not WPI and LDPE films. LDPE and WPI films kept significantly (P<0.01) higher tensile strength (TS) than PS films at high RH (90%). Oxygen permeability (OP) of all films was very low (<0.5 cm3 μm m-2 d-1 kPa-1) below 40% RH but increased for PS films and became significantly (P<0.01) different than that of LDPE and WPI at > 40% RH. Oxygen permeability of WPI and LDPE did not adversely affected by increasing RH to 65%. Furthermore, WPI and LDPE films had lower degree of hydration at 50% and 90% RH and total soluble matter than PS films. These results suggest that WPI could be successfully replacing LDPE in packaging of moist products.

A natural vanishing act: the enzyme-catalyzed degradation of carbon nanomaterials.

PubMed

Kotchey, Gregg P; Hasan, Saad A; Kapralov, Alexander A; Ha, Seung Han; Kim, Kang; Shvedova, Anna A; Kagan, Valerian E; Star, Alexander

2012-10-16

Over the past three decades, revolutionary research in nanotechnology by the scientific, medical, and engineering communities has yielded a treasure trove of discoveries with diverse applications that promise to benefit humanity. With their unique electronic and mechanical properties, carbon nanomaterials (CNMs) represent a prime example of the promise of nanotechnology with applications in areas that include electronics, fuel cells, composites, and nanomedicine. Because of toxicological issues associated with CNMs, however, their full commercial potential may not be achieved. The ex vitro, in vitro, and in vivo data presented in this Account provide fundamental insights into the biopersistence of CNMs, such as carbon nanotubes and graphene, and their oxidation/biodegradation processes as catalyzed by peroxidase enzymes. We also communicate our current understanding of the mechanism for the enzymatic oxidation and biodegradation. Finally, we outline potential future directions that could enhance our mechanistic understanding of the CNM oxidation and biodegradation and could yield benefits in terms of human health and environmental safety. The conclusions presented in this Account may catalyze a rational rethinking of CNM incorporation in diverse applications. For example, armed with an understanding of how and why CNMs undergo enzyme-catalyzed oxidation and biodegradation, researchers can tailor the structure of CNMs to either promote or inhibit these processes. In nanomedical applications such as drug delivery, the incorporation of carboxylate functional groups could facilitate biodegradation of the nanomaterial after delivery of the cargo. On the other hand, in the construction of aircraft, a CNM composite should be stable to oxidizing conditions in the environment. Therefore, pristine, inert CNMs would be ideal for this application. Finally, the incorporation of CNMs with defect sites in consumer goods could provide a facile mechanism that promotes the degradation of these materials once these products reach landfills.

Screening methods for assessment of biodegradability of chemicals in seawater--results from a ring test

DOE Office of Scientific and Technical Information (OSTI.GOV)

Nyholm, N.; Kristensen, P.

1992-04-01

An international ring test involving 14 laboratories was organized on behalf of the Commission of the European Economic Communities (EEC) with the purpose of evaluating two proposed screening methods for assessment of biodegradability in seawater: (a) a shake flask die-away test based primarily on analysis of dissolved organic carbon and (b) a closed bottle test based on determination of dissolved oxygen. Both tests are performed with nutrient-enriched natural seawater as the test medium and with no inoculum added other than the natural seawater microflora. The test methods are seawater versions of the modified OECD screening test and the closed bottlemore » test, respectively, adopted by the Organization for Economic Cooperation and Development (OECD) and by the EEC as tests for ready biodegradability.' The following five chemicals were examined: sodium benzoate, aniline, diethylene glycol, pentaerythritol, and 4-nitrophenol. Sodium benzoate and aniline, which are known to be generally readily biodegradable consistently degraded in practically all tests, thus demonstrating the technical feasibility of the methods. Like in previous ring tests with freshwater screening methods variable results were obtained with the other three compounds, which is believed primarily to be due to site-specific differences between the microflora of the different seawater samples used and to some extent also to differences in the applied concentrations of test material. A positive result with the screening methods indicates that the test substance will most likely degrade relatively rapidly in seawater from the site of collection, while a negative test result does not preclude biodegradability under environmental conditions where the concentrations of chemicals are much lower than the concentrations applied for analytical reasons in screening tests.« less

Bioremediation of PCB-contaminated shallow river sediments: The efficacy of biodegradation using individual bacterial strains and their consortia.

PubMed

Horváthová, Hana; Lászlová, Katarína; Dercová, Katarína

2018-02-01

Elimination of dangerous toxic and hydrophobic chlorinated aromatic compounds, mainly PCBs from the environment, is one of the most important aims of the environmental biotechnologies. In this work, biodegradation of an industrial mixture of PCBs (Delor 103, equivalent to Aroclor 1242) was performed using bacterial consortia composed of four bacterial strains isolated from the historically PCB-contaminated sediments and characterized as Achromobacter xylosoxidans, Stenotrophomonas maltophilia, Ochrobactrum anthropi and Rhodococcus ruber. The objective of this research was to determine the biodegradation ability of the individual strains and artificially prepared consortia composed of two or three bacterial strains mentioned above. Based on the growth parameters, six consortia were constructed and inoculated into the historically contaminated sediment samples collected in the efflux canal of Chemko Strážske plant - the former producer of the industrial mixtures of PCBs. The efficacy of the biotreatment, namely bioaugmentation, was evaluated by determination of ecotoxicity of treated and non-treated sediments. The most effective consortia were those containing the strain R. ruber. In the combination with A. xylosoxidans, the biodegradation of the sum of the indicator congeners was 85% and in the combination with S. maltophilia nearly 80%, with inocula applied in the ratio 1:1 in both cases. Consortium containing the strain R. ruber and S. maltophilia showed pronounced degradation of the highly chlorinated PCB congeners. Among the consortia composed of three bacterial strains, only that consisting of O. anthropi, R. ruber and A. xylosoxidans showed higher biodegradation (73%). All created consortia significally reduced the toxicity of the contaminated sediment. Copyright © 2017 Elsevier Ltd. All rights reserved.

A Natural Vanishing Act: The Enzyme-Catalyzed Degradation of Carbon Nanomaterials

PubMed Central

Kotchey, Gregg P.; Hasan, Saad A.; Kapralov, Alexander A.; Ha, Seung Han; Kim, Kang; Shvedova, Anna A.; Kagan, Valerian E.; Star, Alexander

2012-01-01

CONSPECTUS Over the past three decades, revolutionary research in nanotechnology by the scientific, medical, and engineering communities has yielded a treasure trove of discoveries with diverse applications that promise to benefit humanity. With their unique electronic and mechanical properties, carbon nanomaterials (CNMs) represent a prime example of the promise of nanotechnology with applications in areas that include electronics, fuel cells, composites, and nanomedicine. Because of toxicological issues associated with CNMs, however, their full commercial potential may not be achieved. The ex vitro, in vitro, and in vivo data presented in this Account provide fundamental insights into the biopersistence of CNMs, such as carbon nanotubes and graphene, and their oxidation/biodegradation processes as catalyzed by peroxidase enzymes. We also communicate our current understanding of the mechanism for the enzymatic oxidation/biodegradation. Finally, we outline potential future directions that could enhance our mechanistic understanding of the CNM oxidation/biodegradation and could yield benefits in terms of human health and environmental safety. The conclusions presented in this Account may catalyze a rational rethinking of CNM incorporation in diverse applications. For example, armed with an understanding of how and why CNMs undergo enzyme-catalyzed oxidation/biodegradation, researchers can tailor the structure of CNMs to either promote or inhibit these processes. In nanomedical applications such as drug delivery, the incorporation of carboxylate functional groups could facilitate biodegradation of the nanomaterial after delivery of the cargo. On the other hand, in the construction of aircraft, a CNM composite material should be stable to oxidizing conditions in the environment. Therefore, pristine, inert CNMs would be ideal for this application. Finally, the incorporation of CNMs with defect sites in consumer goods could provide a facile mechanism that promotes the degradation of these materials once these products reach landfills. PMID:22824066

A stoichiometric organic matter decomposition model in a chemostat culture.

PubMed

Kong, Jude D; Salceanu, Paul; Wang, Hao

2018-02-01

Biodegradation, the disintegration of organic matter by microorganism, is essential for the cycling of environmental organic matter. Understanding and predicting the dynamics of this biodegradation have increasingly gained attention from the industries and government regulators. Since changes in environmental organic matter are strenuous to measure, mathematical models are essential in understanding and predicting the dynamics of organic matters. Empirical evidence suggests that grazers' preying activity on microorganism helps to facilitate biodegradation. In this paper, we formulate and investigate a stoichiometry-based organic matter decomposition model in a chemostat culture that incorporates the dynamics of grazers. We determine the criteria for the uniform persistence and extinction of the species and chemicals. Our results show that (1) if at the unique internal steady state, the per capita growth rate of bacteria is greater than the sum of the bacteria's death and dilution rates, then the bacteria will persist uniformly; (2) if in addition to this, (a) the grazers' per capita growth rate is greater than the sum of the dilution rate and grazers' death rate, and (b) the death rate of bacteria is less than some threshold, then the grazers will persist uniformly. These conditions can be achieved simultaneously if there are sufficient resources in the feed bottle. As opposed to the microcosm decomposition models' results, in a chemostat culture, chemicals always persist. Besides the transcritical bifurcation observed in microcosm models, our chemostat model exhibits Hopf bifurcation and Rosenzweig's paradox of enrichment phenomenon. Our sensitivity analysis suggests that the most effective way to facilitate degradation is to decrease the dilution rate.

Thermal and Mechanical Properties of Natural Rubber Composites Reinforced with Cellulose Nanocrystals from Southern Pine

Treesearch

Chunmei Zhang; Yi Dan; Jun Peng; Lih-Sheng Turng; Ronald Sabo; Craig Clemons

2014-01-01

There is currently a considerable interest in developing bio-based and green nanocomposites in industrial and technological areas owing to their biodegradability, biocompatibility, and environmental friendliness. In this study, a bio-based nanosized material, cellulose nanocrystals (CNC), extracted from southern pine pulp was employed as a reinforcing agent in a...

Lightweight and Compostable Fiberboard for the Military

DTIC Science & Technology

2012-08-01

individual sheets with compression molding methods. The second approach examined different biodegradable coatings for paper formation which enhanced wet...strength properties of paper based products. The third approach identified effective coated corrugated alternatives that exhibited comparable...fiberboard containers to different environmental conditions. Analysis of variance of compression data as a function of moisture, insert design and paper

Some Environmental Consequences of a Release of Ethanol to Ground Water

EPA Science Inventory

Estimates on the concentration of ethanol in ground water as a result of a spill of gasoline containing 10% to 15% ethanol vary from approximately 4,000 mg/L to 15,000 mg/L. Published data on the rate of ethanol biodegradation vary from 2 mg/L per day to greater than 500 mg/L ...

Biodegradation of 2,4-Dinitrotoluene and 2,6-Dinitrotoluene in a Pilot-Scale Aerobic Slurry Reactor System

DTIC Science & Technology

1999-09-28

Phytoremediation is generally economically favorable and environmentally acceptable relative to other more intrusive remediation technologies, but... leachate is 0.13 mg/L for 2,4- DNT, but no standard is available for 2,6-DNT and TNT. It should be pointed out that the observed residual concentrations

Feasibility of white-rot fungi for biodegradation of PCP-treated ammunition boxes. Final report

DOE Office of Scientific and Technical Information (OSTI.GOV)

Scholze, R.J.; Lamar, R.T.; Bolduc, J.

1995-01-01

Millions of pounds of wood ammunition boxes treated with the wood preservative pentachiorophenol (PCP) are being stockpiled at military installations, primarily depots, because cost-effective disposal is not readily available. The Army needs cost-effective and environmentally benign treatment methods for destruction and disposal of PCP-treated wood products. This research investigated the use of white-rot fungi to biodegrade PCP-treated wood. Results showed that white-rot fungi effectively decreased the PCP concentration in contaminated hardwood and softwood chips. Under ideal laboratory conditions the fungi reduced the PCP concentration by 80 percent; a field study showed only a 30 percent decrease in PCP concentration. Despitemore » this disparity, this study demonstrated the feasibility of using white-rot fungi to reduce PCP in treated wood.« less

Polysaccharide-Based Membranes in Food Packaging Applications

PubMed Central

Ferreira, Ana R. V.; Alves, Vítor D.; Coelhoso, Isabel M.

2016-01-01

Plastic packaging is essential nowadays. However, the huge environmental problem caused by landfill disposal of non-biodegradable polymers in the end of life has to be minimized and preferentially eliminated. The solution may rely on the use of biopolymers, in particular polysaccharides. These macromolecules with film-forming properties are able to produce attracting biodegradable materials, possibly applicable in food packaging. Despite all advantages of using polysaccharides obtained from different sources, some drawbacks, mostly related to their low resistance to water, mechanical performance and price, have hindered their wider use and commercialization. Nevertheless, with increasing attention and research on this field, it has been possible to trace some strategies to overcome the problems and recognize solutions. This review summarizes some of the most used polysaccharides in food packaging applications. PMID:27089372

Breakdown of plastics and polymers by microorganisms.

PubMed

Kawai, F

1995-01-01

The interest in environmental issues is still growing and there are increasing demands to develop materials which do not burden the environment significantly. Awareness of the waste problem and its impact on the environment has awakened new interest in the area of degradable polymers. Biodegradation is necessary for water-soluble or water-miscible polymers because they eventually enter streams which can neither be recycled nor incinerated. It is important to consider the microbial degradation of natural and synthetic polymers in order to understand what is necessary for biodegradation and the mechanisms involved. This requires both biochemical insight and understanding of the interactions between materials and microorganisms. It is now widely requested that polymeric materials come from renewable resources instead of petrochemical sources. The microbial production of polymeric and oligomeric materials is also described.

Eco-Challenges of Bio-Based Polymer Composites

PubMed Central

Avella, Maurizio; Buzarovska, Aleksandra; Errico, Maria Emanuela; Gentile, Gennaro; Grozdanov, Anita

2009-01-01

In recent years bio-based polymer composites have been the subject of many scientific and research projects, as well as many commercial programs. Growing global environmental and social concern, the high rate of depletion of petroleum resources and new environmental regulations have forced the search for new composites and green materials, compatible with the environment. The aim of this article is to present a brief review of the most suitable and commonly used biodegradable polymer matrices and NF reinforcements in eco-composites and nanocomposites, with special focus on PLA based materials.

NanoPad: an integrated platform for bacterial production of camel nanobodies aimed at detecting environmental biomarkers.

PubMed

Fraile, Sofía; Jiménez, Jose I; Gutiérrez, Carlos; de Lorenzo, Víctor

2013-10-01

The presence of given antigens in environmental samples (e.g. biodegradative enzymes) reports the quality and catalytic vigor of particular soils or aquatic ecosystems. In this context, we have developed the NanoPad system consisting of a complete platform for isolation, amplification, and extracellular production of specific antibodies against antigens that diagnose the occurrence of protein markers in crude environmental samples. The workflow starts with the inoculation of camels (Camelus dromedarius) with various proteins (e.g. catabolic enzymes) for generating a phage display library of variable heavy-chain antibody H fragment (VHH ) domains that bind the different antigens. Instead of being subjected to a conventional panning, such a library is then probed with a Western-panning technique that allows direct isolation of specific binders of proteins blotted on membranes from polyacrylamide gels. Finally, VHH s are fused to the C-domain of hemolysin for secretion to the culture media as virtually pure dimeric proteins that can be used as a primary antibody without further processing. The value of NanoPad is shown with the selection of nanobodies for detection of biphenyl 2,3-dioxygenase, a key enzyme for biodegradation of polychlorinated biphenyls. The thereby generated anti-biphenyl 2,3-dioxygenase VHH s revealed the presence of this enzyme in the metaproteome of an oil refinery waste treatment plant. © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

(Eco)toxicity and biodegradability of protic ionic liquids.

PubMed

Oliveira, Maria V S; Vidal, Bruna T; Melo, Claudia M; de Miranda, Rita de C M; Soares, Cleide M F; Coutinho, João A P; Ventura, Sónia P M; Mattedi, Silvana; Lima, Álvaro S

2016-03-01

Ionic liquids (ILs) are often claimed to be "environmentally friendly" compounds however, the knowledge of their potential toxicity towards different organisms and trophic levels is still limited, in particular when protic ionic liquids (PILs) are addressed. This study aims to evaluate the toxicity against various microorganisms and the biodegradability of four PILs namely, N-methyl-2-hydroxyethylammonium acetate, m-2-HEAA; N-methyl-2-hydroxyethylammonium propionate, m-2-HEAPr; N-methyl-2-hydroxyethylammonium butyrate, m-2-HEAB; and N-methyl-2-hydroxyethylammonium pentanoate, m-2-HEAP. The antimicrobial activity was determined against the two bacteria, Sthaplylococcus aureus ATCC-6533 and Escherichia coli CCT-0355; the yeast Candida albicans ATCC-76645; and the fungi Fusarium sp. LM03. The toxicity of all PILs was tested against the aquatic luminescent marine bacterium Vibrio fischeri using the Microtox(®) test. The impact of the PILs was also studied regarding their effect on lettuce seeds (Lactuta sativa). The biodegradability of these PILs was evaluated using the ratio between the biochemical oxygen demand (BOD) and the chemical oxygen demand (COD). The results show that, in general, the elongation of the alkyl chain tends to increase the negative impact of the PILs towards the organisms and biological systems under study. According to these results, m-2-HEAA and m-2-HEAP are the less and most toxic PILs studied in this work, respectively. Additionally, all the PILs have demonstrated low biodegradability. Copyright © 2016. Published by Elsevier Ltd.

Anaerobic Biodegradation of Alternative Fuels and Associated Biocorrosion of Carbon Steel in Marine Environments.

PubMed

Liang, Renxing; Aktas, Deniz F; Aydin, Egemen; Bonifay, Vincent; Sunner, Jan; Suflita, Joseph M

2016-05-03

Fuels that biodegrade too easily can exacerbate through-wall pitting corrosion of pipelines and tanks and result in unintentional environmental releases. We tested the biological stability of two emerging naval biofuels (camelina-JP5 and Fischer-Tropsch-F76) and their potential to exacerbate carbon steel corrosion in seawater incubations with and without a hydrocarbon-degrading sulfate-reducing bacterium. The inclusion of sediment or the positive control bacterium in the incubations stimulated a similar pattern of sulfate reduction with different inocula. However, the highest rates of sulfate reduction were found in incubations amended with camelina-JP5 [(57.2 ± 2.2)-(80.8 ± 8.1) μM/day] or its blend with petroleum-JP5 (76.7 ± 2.4 μM/day). The detection of a suite of metabolites only in the fuel-amended incubations confirmed that alkylated benzene hydrocarbons were metabolized via known anaerobic mechanisms. Most importantly, general (r(2) = 0.73) and pitting (r(2) = 0.69) corrosion were positively correlated with sulfate loss in the incubations. Thus, the anaerobic biodegradation of labile fuel components coupled with sulfate respiration greatly contributed to the biocorrosion of carbon steel. While all fuels were susceptible to anaerobic metabolism, special attention should be given to camelina-JP5 biofuel due to its relatively rapid biodegradation. We recommend that this biofuel be used with caution and that whenever possible extended storage periods should be avoided.

Remediation of soil co-contaminated with petroleum and heavy metals by the integration of electrokinetics and biostimulation.

PubMed

Dong, Zhi-Yong; Huang, Wen-Hui; Xing, Ding-Feng; Zhang, Hong-Feng

2013-09-15

Successful remediation of soil co-contaminated with high levels of organics and heavy metals is a challenging task, because that metal pollutants in soil can partially or completely suppress normal heterotrophic microbial activity and thus hamper biodegradation of organics. In this study, the benefits of integrating electrokinetic (EK) remediation with biodegradation for decontaminating soil co-contaminated with crude oil and Pb were evaluated in laboratory-scale experiments lasting for 30 days. The treated soil contained 12,500 mg/kg of total petroleum hydrocarbons (TPH) and 450 mg/kg Pb. The amendments of EDTA and Tween 80, together with a regular refreshing of electrolyte showed the best performance to remediate this contaminated soil. An important function of EDTA-enhanced EK treatment was to eliminate heavy metal toxicity from the soil, thus activating microbial degradation of oil. Although Tween 80 reduced current, it could serve as a second substrate for enhancing microbial growth and biodegradation. It was found that oil biodegradation degree and microbial numbers increased toward the anode and cathode. Microbial metabolism was found to be beneficial to metal release from the soil matrix. Under the optimum conditions, the soil Pb and TPH removal percentages after 30 days of running reached 81.7% and 88.3%, respectively. After treatment, both the residual soil Pb and TPH concentrations met the requirement of the Chinese soil environmental quality standards. Copyright © 2013 Elsevier B.V. All rights reserved.

Microbial degradation of decabromodiphenyl ether (DBDE) in soil slurry microcosms.

PubMed

Chou, Hsi-Ling; Hwa, Mei-Yin; Lee, Yao-Chuan; Chang, Yu-Jie; Chang, Yi-Tang

2016-03-01

Decabromodiphenyl ether (DBDE), which has been identified as an endocrine disrupting compound, is used as brominated flame retardant, and this can result in serious bioaccumulation within ecological systems. The objective of this study was to explore DBDE bioremediation (25 mg/kg) using laboratory scale soil slurry microcosms. It was found that effective biodegradation of DBDE occurred in all microcosms. Various biometabolites were identified, namely polybrominated diphenyl ethers congeners and hydroxylated brominated diphenyl ether. Reductive debrominated products such as tri-BDE to hepta-BDE congeners were also detected, and their total concentrations ranged from 77.83 to 91.07 ng/g. The mechanism of DBDE biodegradation in soil slurry microcosms is proposed to consist of a series of biological reactions involving hydroxylation and debromination. Catechol 2,3-oxygenase genes, which are able to bring about meta-cleavage at specific unbrominated locations in carbon backbones, were identified as present during the DBDE biodegradation. No obvious effect on the ecological functional potential based on community-level physiological profiling was observed during DBDE biodegradation, and one major facultative Pseudomonas sp. (99 % similarity) was identified in the various soil slurry microcosms. These findings provide an important basis that should help environmental engineers to design future DBDE bioremediation systems that use a practical microcosm system. A bacterial-mixed culture can be selected as part of the bioaugmentation process for in situ DBDE bioremediation. A soil/water microcosm system can be successfully applied to carry out ex situ DBDE bioremediation.

Biodegradation of a surrogate naphthenic acid under denitrifying conditions.

PubMed

Gunawan, Yetty; Nemati, Mehdi; Dalai, Ajay

2014-03-15

Extraction of bitumen from the shallow oil sands generates extremely large volumes of waters contaminated by naphthenic acid which pose severe environmental and ecological risks. Aerobic biodegradation of NA in properly designed bioreactors has been investigated in our earlier works. In the present work, anoxic biodegradation of trans-4-methyl-1-cyclohexane carboxylic acid (trans-4MCHCA) coupled to denitrification was investigated as a potential ex situ approach for the treatment of oil sand process waters in bioreactors whereby excessive aeration cost could be eliminated, or as an in situ alternative for the treatment of these waters in anoxic stabilization ponds amended with nitrate. Using batch and continuous reactors (CSTR and biofilm), effects of NA concentration (100-750mgL(-1)), NA loading rate (up to 2607.9mgL(-1)h(-1)) and temperature (10-35°C) on biodegradation and denitrification processes were evaluated. In the batch system biodegradation of trans-4MCHCA coupled to denitrification occurred even at the highest concentration of 750mgL(-1). Consistent with the patterns reported for aerobic biodegradation, increase in initial concentration of NA led to higher biodegradation and denitrification rates and the optimum temperature was determined as 23-24°C. In the CSTR, NA removal and nitrate reduction rates passed through a maximum due to increases in NA loading rate. NA loading rate of 157.8mgL(-1)h(-1) at which maximum anoxic NA and nitrate removal rates (105.3mgL(-1)h(-1) and 144.5mgL(-1)h(-1), respectively) occurred was much higher than those reported for the aerobic alternative (NA loading and removal rates: 14.2 and 9.6mgL(-1)h(-1), respectively). In the anoxic biofilm reactor removal rates of NA and nitrate were dependent on NA loading rate in a linear fashion for the entire range of applied loading rates. The highest loading and removal rates for NA were 2607.9 and 2028.1mgL(-1)h(-1), respectively which were at least twofold higher than the values reported for the aerobic biofilm reactor. The highest nitrate removal rate coincided with maximum removal rate of NA and was 3164.7mgL(-1)h(-1). Copyright © 2014 Elsevier Ltd. All rights reserved.

Processing and characterization of solid and microcellular biobased and biodegradable PHBV-based polymer blends and composites

NASA Astrophysics Data System (ADS)

Javadi, Alireza

Petroleum-based polymers have made a significant contribution to human society due to their extraordinary adaptability and processability. However, due to the wide-spread application of plastics over the past few decades, there are growing concerns over depleting fossil resources and the undesirable environmental impact of plastics. Most of the petroleum-based plastics are non-biodegradable and thus will be disposed in landfills. Inappropriate disposal of plastics may also become a potential threat to the environment. Many approaches, such as efficient plastics waste management and replacing petroleum-based plastics with biodegradable materials obtained from renewable resources, have been put forth to overcome these problems. Plastics waste management is at its beginning stages of development which is also more expensive than expected. Thus, there is a growing interest in developing sustainable biobased and biodegradable materials produced from renewable resources such as plants and crops, which can offer comparable performance with additional advantages, such as biodegradability, biocompatibility, and reducing the carbon footprint. Poly(3-hydroxybutyrate-co-3-hydroxyvalerate) (PHBV) is one of the most promising biobased and biodegradable polymers, In fact many petroleum based polymers such as poly(propylene) (PP) can be potentially replaced by PHBV because of the similarity in their properties. Despite PHBV's attractive properties, there are many drawbacks such as high cost, brittleness, and thermal instability, which hamper the widespread usage of this specific polymer. The goals of this study are to investigate various strategies to address these drawbacks, including blending with other biodegradable polymers such as poly (butylene adipate-coterephthalate) (PBAT) or fillers (e.g., coir fiber, recycled wood fiber, and nanofillers) and use of novel processing technologies such as microcellular injection molding technique. Microcellular injection molding technique will not only reduce cost but also improve processability due to the use of supercritical fluid. Various material properties of the solid (without the foaming agent) and microcellular components (with foaming agent) made of PHBV-based polymer blends or composites were investigated including static mechanical properties (tensile testing), dynamic mechanical properties (dynamic mechanical analysis), thermal properties (differential scanning calorimetry and thermo gravimetric analysis), crystallinity(wide angle X-ray scattering analysis), and morphology (scanning electron microscopy and transmission electron microscopy). The composition-processing-structure-property relationship of these solid and microcellular components were established.

Widespread ability of fungi to drive quinone redox cycling for biodegradation.

PubMed

Krueger, Martin C; Bergmann, Michael; Schlosser, Dietmar

2016-06-01

Wood-rotting fungi possess remarkably diverse extracellular oxidation mechanisms, including enzymes, such as laccase and peroxidases, and Fenton chemistry. The ability to biologically drive Fenton chemistry by the redox cycling of quinones has previously been reported to be present in both ecologically diverging main groups of wood-rotting basidiomycetes. Therefore, we investigated whether it is even more widespread among fungal organisms. Screening of a diverse selection of a total of 18 ascomycetes and basidiomycetes for reduction of the model compound 2,6-dimethoxy benzoquinone revealed that all investigated strains were capable of reducing it to its corresponding hydroquinone. In a second step, depolymerization of the synthetic polymer polystyrene sulfonate was used as a proxy for quinone-dependent Fenton-based biodegradation capabilities. A diverse subset of the strains, including environmentally ubiquitous molds, white-rot fungi, as well as peatland and aquatic isolates, caused substantial depolymerization indicative for the effective employment of quinone redox cycling as biodegradation tool. Our results may also open up new paths to utilize diverse fungi for the bioremediation of recalcitrant organic pollutants. © FEMS 2016. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

Polyhydroxybutyrate production from marine source and its application.

PubMed

Kavitha, Ganapathy; Rengasamy, Ramasamy; Inbakandan, Dhinakarasamy

2018-05-01

The increasing significance of non-degradable plastic wastes is an emerging concern. As a substitute, researches are being endeavoured from existing reserve to yield bioplastics based on their properties of biodegradability. Owing to their cost, now the experts are quest for a substitute source like bacteria, microalgae, actinomycetes, cyanobacteria and plants. PHB is biodegradable, environmental friendly and biocompatible thermoplastics. Varying in toughness and flexibility, depending on their formulation, they are used in various ways similar to many non-biodegradable petrochemical plastics currently in use. Promising strategies contain genetic engineering of microorganisms to introduce production pathways examined for the past two decades. Such kind of researches focusing on the use of unconventional substrates, novel extraction methods, and genetically enhanced species with assessment to make PHB from marine microbes are commercially attractive field. Hence, this biopolymer synthesis may displayed as one of the survival mechanisms of endosymbiotic, macroalgae, or sponge-associated bacteria, which exist in a highly competitive and stressful marine microenvironment. This review throws light on the promising and growing awareness of using marine microbes as PHB source, along with their applications in different fields of aquaculture, medicine, antifouling and tissue engineering. Copyright © 2018 Elsevier B.V. All rights reserved.

Biodegradation of thermally treated high-density polyethylene (HDPE) by Klebsiella pneumoniae CH001.

PubMed

Awasthi, Shraddha; Srivastava, Pratap; Singh, Pardeep; Tiwary, D; Mishra, Pradeep Kumar

2017-10-01

Biodegradation of plastics, which are the potential source of environmental pollution, has received a great deal of attention in the recent years. We aim to screen, identify, and characterize a bacterial strain capable of degrading high-density polyethylene (HDPE). In the present study, we studied HDPE biodegradation using a laboratory isolate, which was identified as Klebsiella pneumoniae CH001 (Accession No MF399051). The HDPE film was characterized by Universal Tensile Machine (UTM), Fourier Transform Infrared Spectroscopy (FTIR), Scanning Electron Microscope (SEM), and Atomic Force Microscope (AFM) before and after microbial incubation. We observed that this strain was capable of adhering strongly on HDPE surface and form a thick biofilm, when incubated in nutrient broth at 30 °C on 120 rpm for 60 days. UTM analysis showed a significant decrease in weight (18.4%) and reduction in tensile strength (60%) of HDPE film. Furthermore, SEM analysis showed the cracks on the HDPE surface, whereas AFM results showed an increase in surface roughness after bacterial incubation. Overall, these results indicate that K. pneumoniae CH001 can be used as potential candidate for HDPE degradation in eco-friendly and sustainable manner in the environment.

Macrofouling communities and the degradation of plastic bags in the sea: an in situ experiment.

PubMed

Pauli, Nora-Charlotte; Petermann, Jana S; Lott, Christian; Weber, Miriam

2017-10-01

The increasing amount of plastic littered into the sea may provide a new substratum for benthic organisms. These marine fouling communities on plastic have not received much scientific attention. We present, to our knowledge, the first comprehensive analysis of their macroscopic community composition, their primary production and the polymer degradation comparing conventional polyethylene (PE) and a biodegradable starch-based plastic blend in coastal benthic and pelagic habitats in the Mediterranean Sea. The biomass of the fouling layer increased significantly over time and all samples became heavy enough to sink to the seafloor. The fouling communities, consisting of 21 families, were distinct between habitats, but not between polymer types. Positive primary production was measured in the pelagic, but not in the benthic habitat, suggesting that large accumulations of floating plastic could pose a source of oxygen for local ecosystems, as well as a carbon sink. Contrary to PE, the biodegradable plastic showed a significant loss of tensile strength and disintegrated over time in both habitats. These results indicate that in the marine environment, biodegradable polymers may disintegrate at higher rates than conventional polymers. This should be considered for the development of new materials, environmental risk assessment and waste management strategies.

Ethanolic extract of propolis for biodegradable films packaging enhanced with chitosan

NASA Astrophysics Data System (ADS)

Ismail, M. I.; Roslan, A.; Saari, N. S.; Hashim, K. H.; Kalamullah, M. R.

2017-09-01

The use of industrial organic waste which are chitosan and propolis as materials for the development of biodegradable and active packaging is economical and environmentally appealing. Processing of propolis-chitosan film can minimize waste, and produce low-cost added value biopolymer packaging films for targeted applications. This aims of this research is to develop and characterize a biodegradable films by incorporating chitosan with propolis extract to enhance the functional properties for potential use as active food packaging. The film's moisture content, solubility and antimicrobial activity increase due to increasing volume of propolis extract which are 0 ml, 1.2 ml and 2.4 ml of propolis extract. Propolis-chitosan film with 2.4 ml of propolis extract is more soluble in water compared to propolis-chitosan film with 0 ml of propolis extract and 1.2 ml of propolis extract. The higher the volume of the propolis extract used, the higher the solubility of film in the water. The moisture content also will increase when higher volume of propolis extract used. Characterization of moisture content, solubility and antimicrobial activities revealed the benefits of adding propolis extract into chitosan films and the potential of using the developed film as active food packaging.

Towards more realistic in vitro release measurement techniques for biodegradable microparticles.

PubMed

Klose, D; Azaroual, N; Siepmann, F; Vermeersch, G; Siepmann, J

2009-03-01

To better understand the importance of the environmental conditions for drug release from biodegradable microparticles allowing for the development of more appropriate in vitro release measurement techniques. Propranolol HCl diffusion in various agarose gels was characterized by NMR and UV analysis. Fick's law was used to theoretically predict the mass transport kinetics. Drug release from PLGA-based microparticles in such agarose gels was compared to that measured in agitated bulk fluids ("standard" method). NMR analysis revealed that the drug diffusivity was almost independent of the hydrogel concentration, despite of the significant differences in the systems' mechanical properties. This is due to the small size of the drug molecules/ions with respect to the hydrogel mesh size. Interestingly, the theoretically predicted drug concentration-distance-profiles could be confirmed by independent experiments. Most important from a practical point of view, significant differences in the release rates from the same batch of PLGA-based microparticles into a well agitated bulk fluid versus a semi-solid agarose gel were observed. Great care must be taken when defining the in vitro conditions for drug release measurements from biodegradable microparticles. The obtained new insight can help facilitating the development of more appropriate in vitro release testing procedures.

Evaluating the environmental parameters that determine aerobic biodegradation half-lives of pesticides in soil with a multivariable approach.

PubMed

Wang, Yuxin; Lai, Adelene; Latino, Diogo; Fenner, Kathrin; Helbling, Damian E

2018-06-14

Aerobic biodegradation half-lives (half-lives) are key parameters used to evaluate pesticide persistence in soil. However, half-life estimates for individual pesticides often span several orders of magnitude, reflecting the impact that various environmental or experimental parameters have on half-lives in soil. In this work, we collected literature-reported half-lives for eleven pesticides along with associated metadata describing the environmental or experimental conditions under which they were derived. We then developed a multivariable framework to discover relationships between the half-lives and associated metadata. We first compared data for the herbicide atrazine collected from 95 laboratory and 65 field studies. We discovered that atrazine application history and soil texture were the parameters that have the largest influence on the observed half-lives in both types of studies. We then extended the analysis to include ten additional pesticides with data collected exclusively from laboratory studies. We found that, when data were available, pesticide application history and biomass concentrations were always positively associated with half-lives. The relevance of other parameters varied among the pesticides, but in some cases the variability could be explained by the physicochemical properties of the pesticides. For example, we found that the relative significance of the organic carbon content of soil for determining half-lives depends on the relative solubility of the pesticide. Altogether, our analyses highlight the reciprocal influence of both environmental parameters and intrinsic physicochemical properties for determining half-lives in soil. Copyright © 2018 Elsevier Ltd. All rights reserved.

Cigarettes Butts and the Case for an Environmental Policy on Hazardous Cigarette Waste

PubMed Central

Novotny, Thomas E.; Lum, Kristen; Smith, Elizabeth; Wang, Vivian; Barnes, Richard

2009-01-01

Discarded cigarette butts are a form of non-biodegradable litter. Carried as runoff from streets to drains, to rivers, and ultimately to the ocean and its beaches, cigarette filters are the single most collected item in international beach cleanups each year. They are an environmental blight on streets, sidewalks, and other open areas. Rather than being a protective health device, cigarette filters are primarily a marketing tool to help sell ‘safe’ cigarettes. They are perceived by much of the public (especially current smokers) to reduce the health risks of smoking through technology. Filters have reduced the machine-measured yield of tar and nicotine from burning cigarettes, but there is controversy as to whether this has correspondingly reduced the disease burden of smoking to the population. Filters actually may serve to sustain smoking by making it seem less urgent for smokers to quit and easier for children to initiate smoking because of reduced irritation from early experimentation. Several options are available to reduce the environmental impact of cigarette butt waste, including developing biodegradable filters, increasing fines and penalties for littering butts, monetary deposits on filters, increasing availability of butt receptacles, and expanded public education. It may even be possible to ban the sale of filtered cigarettes altogether on the basis of their adverse environmental impact. This option may be attractive in coastal regions where beaches accumulate butt waste and where smoking indoors is increasingly prohibited. Additional research is needed on the various policy options, including behavioral research on the impact of banning the sale of filtered cigarettes altogether. PMID:19543415

Environmental Impact of Flame Retardants (Persistence and Biodegradability)

PubMed Central

Segev, Osnat; Kushmaro, Ariel; Brenner, Asher

2009-01-01

Flame-retardants (FR) are a group of anthropogenic environmental contaminants used at relatively high concentrations in many applications. Currently, the largest market group of FRs is the brominated flame retardants (BFRs). Many of the BFRs are considered toxic, persistent and bioaccumulative. Bioremediation of contaminated water, soil and sediments is a possible solution for the problem. However, the main problem with this approach is the lack of knowledge concerning appropriate microorganisms, biochemical pathways and operational conditions facilitating degradation of these chemicals at an acceptable rate. This paper reviews and discusses current knowledge and recent developments related to the environmental fate and impact of FRs in natural systems and in engineered treatment processes. PMID:19440395

What a Waste! A Teacher's Resource for Integrating the Solid Waste Crisis into the Classroom.

ERIC Educational Resources Information Center

Horosko, Millie M., Ed.

Although consumers are sensitive to purchasing products that are recyclable and biodegradable, which products are truly environmentally sound is not clear. This teacher guide contains activities to help educate students in grades 3-6 about choices they and their families make that may affect their future health and welfare. The lessons may be…

Plasmonic Paper as a Highly Efficient SERS Substrate

DTIC Science & Technology

2012-09-01

trinitrotoluene (TNT), which inherently have low vapor pressure (~10 ppbv at room temperature), intentional packaging further lowers the actual vapor...responders and military personal but also to several areas of medical, food analysis, and environmental research. We and others have introduced a...products because its source (cellulose) is abundant in nature, renewable, inexpensively produced and recycled.31 Paper is also biodegradable

THE ENVIRONMENTAL CONSEQUENCES OF A RELEASE OF ETHANOL TO GROUND WATER-POSTER PRESENTATION

EPA Science Inventory

Estimates on the concentration of ethanol in ground water as a result of a spill of gasoline containing 10% to 15% ethanol vary from approximately 4,000 mg/L to 15,000 mg/L. Published data on the rate of ethanol biodegradation vary from 2.6 mg/L per day to greater than 500 mg/...

Transgenic plants and associated bacteria for phytoremediation of chlorinated compounds.

PubMed

Van Aken, Benoit; Doty, Sharon Lafferty

2010-01-01

Phytoremediation is the use of plants for the treatment of environmental pollution, including chlorinated organics. Although conceptually very attractive, removal and biodegradation of chlorinated pollutants by plants is a rather slow and inefficient process resulting in incomplete treatment and potential release of toxic metabolites into the environment. In order to overcome inherent limitations of plant metabolic capabilities, plants have been genetically modified, following a strategy similar to the development of transgenic crops: genes from bacteria, fungi, and mammals involved in the metabolism of organic contaminants, such as cytochrome P-450 and glutathione S-transferase, have been introduced into higher plants, resulting in significant improvement of tolerance, removal, and degradation of pollutants. Recently, plant-associated bacteria have been recognized playing a significant role in phytoremediation, leading to the development of genetically modified rhizospheric and endophytic bacteria with improved biodegradation capabilities. Transgenic plants and associated bacteria constitute a new generation of genetically modified organisms for efficient and environmental-friendly treatment of polluted soil and water. This review focuses on recent advances in the development of transgenic plants and bacteria for the treatment of chlorinated pollutants, including chlorinated solvents, polychlorinated phenols, and chlorinated herbicides.

Mechanical, Thermomechanical and Reprocessing Behavior of Green Composites from Biodegradable Polymer and Wood Flour

PubMed Central

Morreale, Marco; Liga, Antonio; Mistretta, Maria Chiara; Ascione, Laura; La Mantia, Francesco Paolo

2015-01-01

The rising concerns in terms of environmental protection and the search for more versatile polymer-based materials have led to an increasing interest in the use of polymer composites filled with natural organic fillers (biodegradable and/or coming from renewable resources) as a replacement for traditional mineral inorganic fillers. At the same time, the recycling of polymers is still of fundamental importance in order to optimize the utilization of available resources, reducing the environmental impact related to the life cycle of polymer-based items. Green composites from biopolymer matrix and wood flour were prepared and the investigation focused on several issues, such as the effect of reprocessing on the matrix properties, wood flour loading effects on virgin and reprocessed biopolymer, and wood flour effects on material reprocessability. Tensile, Dynamic-mechanical thermal (DMTA), differential scanning calorimetry (DSC) and creep tests were performed, pointing out that wood flour leads to an improvement of rigidity and creep resistance in comparison to the pristine polymer, without compromising other properties such as the tensile strength. The biopolymer also showed a good resistance to multiple reprocessing; the latter even allowed for improving some properties of the obtained green composites. PMID:28793656

Conceptual Chemical Process Design for Sustainability. ...

EPA Pesticide Factsheets

This chapter examines the sustainable design of chemical processes, with a focus on conceptual design, hierarchical and short-cut methods, and analyses of process sustainability for alternatives. The chapter describes a methodology for incorporating process sustainability analyses throughout the conceptual design. Hierarchical and short-cut decision-making methods will be used to approach sustainability. An example showing a sustainability-based evaluation of chlor-alkali production processes is presented with economic analysis and five pollutants described as emissions. These emissions are analyzed according to their human toxicity potential by ingestion using the Waste Reduction Algorithm and a method based on US Environmental Protection Agency reference doses, with the addition of biodegradation for suitable components. Among the emissions, mercury as an element will not biodegrade, and results show the importance of this pollutant to the potential toxicity results and therefore the sustainability of the process design. The dominance of mercury in determining the long-term toxicity results when energy use is included suggests that all process system evaluations should (re)consider the role of mercury and other non-/slow-degrading pollutants in sustainability analyses. The cycling of nondegrading pollutants through the biosphere suggests the need for a complete analysis based on the economic, environmental, and social aspects of sustainability. Chapter reviews

Nanocellulose in green food packaging.

PubMed

Vilarinho, Fernanda; Sanches Silva, Ana; Vaz, M Fátima; Farinha, José Paulo

2018-06-13

The development of packaging materials with new functionalities and lower environmental impact is now an urgent need of our society. On one hand, the shelf-life extension of packaged products can be an answer to the exponential increase of worldwide demand for food. On the other hand, uncertainty of crude oil prices and reserves has imposed the necessity to find raw materials to replace oil-derived polymers. Additionally, consumers' awareness toward environmental issues increasingly pushes industries to look with renewed interest to "green" solutions. In response to these issues, numerous polymers have been exploited to develop biodegradable food packaging materials. Although the use of biopolymers has been limited due to their poor mechanical and barrier properties, these can be enhanced by adding reinforcing nanosized components to form nanocomposites. Cellulose is probably the most used and well-known renewable and sustainable raw material. The mechanical properties, reinforcing capabilities, abundance, low density, and biodegradability of nanosized cellulose make it an ideal candidate for polymer nanocomposites processing. Here we review the potential applications of cellulose based nanocomposites in food packaging materials, highlighting the several types of biopolymers with nanocellulose fillers that have been used to form bio-nanocomposite materials. The trends in nanocellulose packaging applications are also addressed.

Volatile hydrocarbons and fuel oxygenates: Chapter 12

USGS Publications Warehouse

Cozzarelli, Isabelle M.

2014-01-01

Petroleum hydrocarbons and fuel oxygenates are among the most commonly occurring and widely distributed contaminants in the environment. This chapter presents a summary of the sources, transport, fate, and remediation of volatile fuel hydrocarbons and fuel additives in the environment. Much research has focused on the transport and transformation processes of petroleum hydrocarbons and fuel oxygenates, such as benzene, toluene, ethylbenzene, and xylenes and methyl tert‐butyl ether, in groundwater following release from underground storage tanks. Natural attenuation from biodegradation limits the movement of these contaminants and has received considerable attention as an environmental restoration option. This chapter summarizes approaches to environmental restoration, including those that rely on natural attenuation, and also engineered or enhanced remediation. Researchers are increasingly combining several microbial and molecular-based methods to give a complete picture of biodegradation potential and occurrence at contaminated field sites. New insights into the fate of petroleum hydrocarbons and fuel additives have been gained by recent advances in analytical tools and approaches, including stable isotope fractionation, analysis of metabolic intermediates, and direct microbial evidence. However, development of long-term detailed monitoring programs is required to further develop conceptual models of natural attenuation and increase our understanding of the behavior of contaminant mixtures in the subsurface.

Endocrine activity in an urban river system and the biodegradation of estrogen-like endocrine disrupting chemicals through a bio-analytical approach using DRE- and ERE-CALUX bioassays.

PubMed

Vandermarken, T; Croes, K; Van Langenhove, K; Boonen, I; Servais, P; Garcia-Armisen, T; Brion, N; Denison, M S; Goeyens, L; Elskens, M

2018-06-01

The Zenne River, crossing the Brussels region (Belgium) is an extremely urbanized river impacted by both domestic and industrial effluents. The objective of this study was to monitor the occurrence and activity of Endocrine Active Substances (EAS) in river water and sediments in the framework of the Environmental Quality Standards Directive (2008/105/EC and 2013/39/EU). Activities were determined using Estrogen and Dioxin Responsive Elements (ERE and DRE) Chemical Activated Luciferase Gene Expression (CALUX) bioassays. A potential contamination source of estrogen active compounds was identified in the river at an industrial area downstream from Brussels with a peak value of 938 pg E2 eq./L water (above the EQS of 0.4 ng/L) and 195 pg E2 eq./g sediment. Estrogens are more abundantly present in the sediments than in the dissolved phase. Principal Component Analysis (PCA) showed high correlations between Suspended Particulate Matter (SPM), Particulate (POC) and Dissolved Organic Carbon (DOC) and estrogenic EAS. The dioxin fractions comply with previous data and all were above the United States Environmental Protection Agency (US EPA) low-level risk, with one (42 pg TCDD eq./g sediment) exceeding the high-level risk value for mammals. The self-purifying ability of the Zenne River regarding estrogens was examined with an in vitro biodegradation experiment using the bacterial community naturally present in the river. Hill coefficient and EC 50 values (Effective Concentration at 50%) revealed a process of biodegradation in particulate and dissolved phase. The estrogenic activity was decreased by 80%, demonstrating the ability of self-purification of estrogenic compounds in the Zenne River. Copyright © 2018 Elsevier Ltd. All rights reserved.

Free ammonia pre-treatment of secondary sludge significantly increases anaerobic methane production.

PubMed

Wei, Wei; Zhou, Xu; Wang, Dongbo; Sun, Jing; Wang, Qilin

2017-07-01

Energy recovery in the form of methane from sludge/wastewater is restricted by the poor and slow biodegradability of secondary sludge. An innovative pre-treatment technology using free ammonia (FA, i.e. NH 3 ) was proposed in this study to increase anaerobic methane production. The solubilisation of secondary sludge was significantly increased after FA pre-treatment at up to 680 mg NH 3 -N/L for 1 day, under which the solubilisation (i.e. 0.4 mg SCOD/mg VS; SCOD: soluble chemical oxygen demand; VS: volatile solids) was >10 times higher than that without FA pre-treatment (i.e. 0.03 mg SCOD/mg VS). Biochemical methane potential assays showed that FA pre-treatment at above 250 mg NH 3 -N/L is effective in improving anaerobic methane production. The highest improvement in biochemical methane potential (B 0 ) and hydrolysis rate (k) was achieved at FA concentrations of 420-680 mg NH 3 -N/L, and was determined as approximately 22% (from 160 to 195 L CH 4 /kg VS added) and 140% (from 0.22 to 0.53 d -1 ) compared to the secondary sludge without pre-treatment. More analysis revealed that the FA induced improvement in B 0 and k could be attributed to the rapidly biodegradable substances rather than the slowly biodegradable substances. Economic and environmental analyses showed that the FA-based technology is economically favourable and environmentally friendly. Since this FA technology aims to use the wastewater treatment plants (WWTPs) waste (i.e. anaerobic digestion liquor) to enhance methane production from the WWTPs, it will set an example for the paradigm shift of the WWTPs from 'linear economy' to 'circular economy'. Copyright © 2017 Elsevier Ltd. All rights reserved.

Bacterial metabolism of aromatic compounds and a complex hazardous waste under anaerobic conditions

DOE Office of Scientific and Technical Information (OSTI.GOV)

O'Connor, O.A.

1992-01-01

The biological fate of organic chemicals in the environment depends upon a variety of physical/chemical factors. In the absence of molecular oxygen, the importance of terminal electron acceptors has been often overlooked. Since anaerobic microbial consortia are dependent upon the availability of particular electron acceptors, these conditions can play an important role in influencing the fate of environmental pollutants. In this research, different electron acceptors were evaluated for their effects on the biodegradation of environmental toxicants. Two anaerobic bioassays, the Biochemical Methane Potential (BMP) and the Anaerobic Toxicity Assay (ATA), were used to evaluate a series of phthalic acid estersmore » (PAEs), substituted phenols and a landfill leachate, for their methanogenic biodegradability and toxicity. Many of the PAEs and phenols could be stoichiometrically mineralized. In addition, the landfill leachate was found to be inhibitory at concentrations greater than 10%, and partially mineralized in approximately 50 weeks. Based upon these assays, 6 different functional groups and their isomers were evaluated for their effect on the biodegradability and toxicity of phenol under methanogenic and denitrifying conditions. These results indicated that nitro- and chloro-substituted phenols were persistent under denitrifying conditions. Under methanogenic conditions, these compounds were metabolized to a more reduced intermediate with less toxicity. Conversely, amino-substituted phenols were not readily mineralized under methanogenic conditions, but were metabolized after minimal lag under denitrifying conditions. From active denitrifying phenol degrading cultures, a pure culture was obtained which could grow on phenol and on a variety of other alkyl-substituted aromatic compounds. Additional studies have tentatively identified several alicyclic metabolites including cyclohexanol, 2-cyclohexene-1-ol, cyclohexanone and 2-cyclohexene-1-one from phenol catabolism.« less

Persistence of perfluoroalkylated substances in closed bottle tests with municipal sewage sludge.

PubMed

Sáez, Monica; de Voogt, Pim; Parsons, John R

2008-09-01

Perfluoroalkylated substances (PFAS) are chemicals with completely fluorinated alkyl chains. The specific properties of the F-C bond give PFAS a high stability and make them very useful in a wide range of applications. PFAS also pose a potential risk to the environment and humans because they have been recently characterized as persistent, bioaccumulative, and toxic. The objective of this work is to study the bacterial degradation of PFAS under aerobic and anaerobic conditions in municipal sewage sludge as a contribution toward understanding their environmental fate and behavior. Bacterial communities from sewage sludge were exposed to a mixture of PFAS under aerobic or anaerobic conditions. Individual PFAS concentrations were determined in the experiment media at different exposure times using liquid chromatography-mass spectrometry analysis after extraction with solid-phase extraction. The PFAS analyses of samples of sludge showed repeatable replicate results, allowing a reliable quantification of the different groups of PFAS analyzed. No conclusive evidence for PFAS degradation was observed under the experimental conditions tested in this work. Reduction in concentrations, however, was observed for some PFAS in sludge under aerobic conditions. The largest concentration decrease occurred for the fluorotelomer alcohols (FTOHs), especially for the 8:2 FTOH, which have been described as biodegradable in the literature. However, this concentration decrease could be due to different causes: sorption to glass, septa, or matrix components, as well as bacterial activity. Therefore, it is not certain that biodegradation occurred. PFAS are very recalcitrant chemicals, especially when fully fluorinated. Although some decreases in concentration have been observed for some PFAS, such as the FTOHs, there is no conclusive evidence for biodegradation. It can be concluded that the PFAS tested in these experiments are non-biodegradable under these experimental conditions. Since the presence of PFAS is ubiquitous in the environment and they can be toxic, more research is needed in this field to elucidate which PFAS are susceptible to biodegradation, the conditions required for biodegradation, and the possible routes followed. A possible inhibitory effect of PFAS on bacteria, the threshold concentrations, and conditions of inhibition should also be investigated.

Comparative study of toxicity of azo dye Procion Red MX-5B following biosorption and biodegradation treatments with the fungi Aspergillus niger and Aspergillus terreus.

PubMed

Almeida, E J R; Corso, C R

2014-10-01

Azo dyes are an important class of environmental contaminants and are characterized by the presence of one or more azo bonds (-N=N-) in their molecular structure. Effluents containing these compounds resist many types of treatments due to their molecular complexity. Therefore, alternative treatments, such as biosorption and biodegradation, have been widely studied to solve the problems caused by these substances, such as their harmful effects on the environment and organisms. The aim of the present study was to evaluate biosorption and biodegradation of the azo dye Procion Red MX-5B in solutions with the filamentous fungi Aspergillus niger and Aspergillus terreus. Decolorization tests were performed, followed by acute toxicity tests using Lactuca sativa seeds and Artemia salina larvae. Thirty percent dye removal of the solutions was achieved after 3 h of biosorption. UV-Vis spectroscopy revealed that removal of the dye molecules occurred without major molecular changes. The acute toxicity tests confirmed lack of molecular degradation following biosorption with A. niger, as toxicity to L. sativa seed reduced from 5% to 0%. For A. salina larvae, the solutions were nontoxic before and after treatment. In the biodegradation study with the fungus A. terreus, UV-Vis and FTIR spectroscopy revealed molecular degradation and the formation of secondary metabolites, such as primary and secondary amines. The biodegradation of the dye molecules was evaluated after 24, 240 and 336 h of treatment. The fungal biomass demonstrated considerable affinity for Procion Red MX-5B, achieving approximately 100% decolorization of the solutions by the end of treatment. However, the solutions resulting from this treatment exhibited a significant increase in toxicity, inhibiting the growth of L. sativa seeds by 43% and leading to a 100% mortality rate among the A. salina larvae. Based on the present findings, biodegradation was effective in the decolorization of the samples, but generated toxic metabolites, while biosorption was effective in both decolorization and reducing the toxicity of the solutions. Published by Elsevier Ltd.

Environmental Impact of Ionic Liquids: Recent Advances in (Eco)toxicology and (Bio)degradability.

PubMed

Costa, Susana P F; Azevedo, Ana M O; Pinto, Paula C A G; Saraiva, M Lúcia M F S

2017-06-09

This Review aims to integrate the most recent and pertinent data available on the (bio)degradability and toxicity of ionic liquids for global and critical analysis and on the conscious use of these compounds on a large scale thereafter. The integrated data will enable focus on the recognition of toxicophores and on the way the community has been dealing with them, with the aim to obtain greener and safer ionic liquids. Also, an update of the most recent biotic and abiotic methods developed to overcome some of these challenging issues will be presented. The review structure aims to present a potential sequence of events that can occur upon discharging ionic liquids into the environment and the potential long-term consequences. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

Oil Biodegradation and Bioremediation: A Tale of the Two Worst Spills in U.S. History

PubMed Central

2011-01-01

The devastating environmental impacts of the Exxon Valdez spill in 1989 and its media notoriety made it a frequent comparison to the BP Deepwater Horizon spill in the popular press in 2010, even though the nature of the two spills and the environments impacted were vastly different. Fortunately, unlike higher organisms that are adversely impacted by oil spills, microorganisms are able to consume petroleum hydrocarbons. These oil degrading indigenous microorganisms played a significant role in reducing the overall environmental impact of both the Exxon Valdez and BP Deepwater Horizon oil spills. PMID:21699212

Oil biodegradation and bioremediation: a tale of the two worst spills in U.S. history.

PubMed

Atlas, Ronald M; Hazen, Terry C

2011-08-15

The devastating environmental impacts of the Exxon Valdez spill in 1989 and its media notoriety made it a frequent comparison to the BP Deepwater Horizon spill in the popular press in 2010, even though the nature of the two spills and the environments impacted were vastly different. Fortunately, unlike higher organisms that are adversely impacted by oil spills, microorganisms are able to consume petroleum hydrocarbons. These oil degrading indigenous microorganisms played a significant role in reducing the overall environmental impact of both the Exxon Valdez and BP Deepwater Horizon oil spills.

Biodegradation at Dynamic Plume Fringes: Mixing Versus Reaction Control

NASA Astrophysics Data System (ADS)

Cirpka, O. A.; Eckert, D.; Griebler, C.; Haberer, C.; Kürzinger, P.; Bauer, R.; Mellage, A.

2014-12-01

Biodegradation of continuously emitted plumes is known to be most pronounced at the plume fringe, where mixing of contaminated water and ambient groundwater, containing dissolved electron acceptors, stimulates microbial activity. Under steady-state conditions, physical mixing of contaminant and electron acceptor by transverse dispersion was shown to be the major bottleneck for biodegradation, with plume lengths scaling inversely with the bulk transverse dispersivity in quasi two-dimensional settings. Under these conditions, the presence of suitable microbes is essential but the biokinetic parameters do not play an important role. When the location of the plume shifts (caused, e.g., by a fluctuating groundwater table), however, the bacteria are no more situated at the plume fringe and biomass growth, decay, activation and deactivation determine the time lag until the fringe-controlled steady state is approached again. During this time lag, degradation is incomplete. The objective of the presented study was to analyze to which extent flow and transport dynamics diminish effectiveness of fringe-controlled biodegradation and which microbial processes and related biokinetic parameters determine the system response in overall degradation to hydraulic fluctuations. We performed experiments in quasi-two-dimensional flow through microcosms on aerobic toluene degradation by Pseudomonas putida F1. Plume dynamics were simulated by vertical alteration of the toluene plume position and experimental results were analyzed by reactive-transport modeling. We found that, even after disappearance of the toluene plume for two weeks, the majority of microorganisms stayed attached to the sediment and regained their full biodegradation potential within two days after reappearance of the toluene plume. Our results underline that besides microbial growth and maintenance (often subsumed as "biomass decay") microbial dormancy (that is, change into a metabolically inactive state) and endogeneous respiration are important to understand the dynamic behavior of electron-acceptor and -donor fluxes under transient environmental conditions and therefore deserve increased consideration in future reactive-transport modeling.

Evaluation of the rotary drum reactor process as pretreatment technology of municipal solid waste for thermophilic anaerobic digestion and biogas production.

PubMed

Gikas, Petros; Zhu, Baoning; Batistatos, Nicolas Ion; Zhang, Ruihong

2018-06-15

Municipal solid waste (MSW) contains a large fraction of biodegradable organic materials. When disposed in landfills, these materials can cause adverse environmental impact due to gaseous emissions and leachate generation. This study was performed with an aim of effectively separating the biodegradable materials from a Mechanical Biological Treatment (MBT) facility and treating them in well-controlled anaerobic digesters for biogas production. The rotary drum reactor (RDR) process (a sub-process of the MBT facilities studied in the present work) was evaluated as an MSW pretreatment technology for separating and preparing the biodegradable materials in MSW to be used as feedstock for anaerobic digestion. The RDR processes used in six commercial MSW treatment plants located in the USA were surveyed and sampled. The samples of the biodegradable materials produced by the RDR process were analyzed for chemical and physical characteristics as well as anaerobically digested in the laboratory using batch reactors under thermophilic conditions. The moisture content, TS, VS and C/N of the samples varied between 64.7 and 44.4%, 55.6 to 35.3%, 27.0 to 41.3% and 24.5 to 42.7, respectively. The biogas yield was measured to be between 533.0 and 675.6 mL g -1 VS after 20 days of digestion. Approximately 90% of the biogas was produced during the first 13 days. The average methane content of the biogas was between 58.0 and 59.9%. The results indicated that the biodegradable materials separated from MSW using the RDR processes could be used as an excellent feedstock for anaerobic digestion. The digester residues may be further processed for compost production or further energy recovery by using thermal conversion processes such as combustion or gasification. Copyright © 2017. Published by Elsevier Ltd.

Review of Concrete Biodeterioration in Relation to Buried Nuclear Waste

DOE Office of Scientific and Technical Information (OSTI.GOV)

Turick, C; Berry, C.

Long-term storage of low level radioactive material in below ground concrete disposal units (DUs) (Saltstone Disposal Facility) is a means of depositing wastes generated from nuclear operations of the U.S. Department of Energy. Based on the currently modeled degradation mechanisms, possible microbial induced effects on the structural integrity of buried low level wastes must be addressed. Previous international efforts related to microbial impacts on concrete structures that house low level radioactive waste showed that microbial activity can play a significant role in the process of concrete degradation and ultimately structural deterioration. This literature review examines the recent research in thismore » field and is focused on specific parameters that are applicable to modeling and prediction of the fate of concrete vaults housing stored wastes and the wastes themselves. Rates of concrete biodegradation vary with the environmental conditions, illustrating a need to understand the bioavailability of key compounds involved in microbial activity. Specific parameters require pH and osmotic pressure to be within a certain range to allow for microbial growth as well as the availability and abundance of energy sources like components involved in sulfur, iron and nitrogen oxidation. Carbon flow and availability are also factors to consider in predicting concrete biodegradation. The results of this review suggest that microbial activity in Saltstone, (grouted low level radioactive waste) is unlikely due to very high pH and osmotic pressure. Biodegradation of the concrete vaults housing the radioactive waste however, is a possibility. The rate and degree of concrete biodegradation is dependent on numerous physical, chemical and biological parameters. Results from this review point to parameters to focus on for modeling activities and also, possible options for mitigation that would minimize concrete biodegradation. In addition, key chemical components that drive microbial activity on concrete surfaces are discussed.« less

Impact of heavy metals on the oil products biodegradation process.

PubMed

Zukauskaite, Audrone; Jakubauskaite, Viktorija; Belous, Olga; Ambrazaitiene, Dalia; Stasiskiene, Zaneta

2008-12-01

Oil products continue to be used as a principal source of energy. Wide-scale production, transport, global use and disposal of petroleum have made them major contaminants in prevalence and quantity in the environment. In accidental spills, actions are taken to remove or remediate or recover the contaminants immediately, especially if they occur in environmentally sensitive areas, for example, in coastal zones. Traditional methods to cope with oil spills are confined to physical containment. Biological methods can have an advantage over the physical-chemical treatment regimes in removing spills in situ as they offer biodegradation of oil fractions by the micro-organisms. Recently, biological methods have been known to play a significant role in bioremediation of oil-polluted coastal areas. Such systems are likely to be of significance in the effective management of sensitive coastal ecosystems chronically subjected to oil spillage. For this reason the aim of this paper is to present an impact of Mn, Cu, Co and Mo quantities on oil biodegradation effectiveness in coastal soil and to determine the relationship between metal concentrations and degradation of two oil products (black oil and diesel fuel). Soil was collected in the Baltic Sea coastal zone oil products degradation area (Klaipeda, Lithuania). The experiment consisted of two parts: study on the influence of micro-elements on the oil product biodegradation process; and analysis of the influence of metal concentration on the number of HDMs. The analysis performed and results obtained address the following areas: impact of metal on a population of hydrocarbon degrading micro-organisms, impact of metals on residual concentrations of oil products, influence of metals on the growth of micro-organisms, inter-relation of metal concentrations with degradation rates. Statistical analysis was made using ;Statgraphics plus' software. The influence of metals on the growth of micro-organisms, the biodegradation process rate and the oil product concentrations were evaluated with analysis of variance. The impact has been investigated separately and synergetically.

Biodegradation of polycyclic aromatic hydrocarbons: Using microbial bioelectrochemical systems to overcome an impasse.

PubMed

Kronenberg, Maria; Trably, Eric; Bernet, Nicolas; Patureau, Dominique

2017-12-01

Polycyclic aromatic hydrocarbons (PAHs) are hardly biodegradable carcinogenic organic compounds. Bioremediation is a commonly used method for treating PAH contaminated environments such as soils, sediment, water bodies and wastewater. However, bioremediation has various drawbacks including the low abundance, diversity and activity of indigenous hydrocarbon degrading bacteria, their slow growth rates and especially a limited bioavailability of PAHs in the aqueous phase. Addition of nutrients, electron acceptors or co-substrates to enhance indigenous microbial activity is costly and added chemicals often diffuse away from the target compound, thus pointing out an impasse for the bioremediation of PAHs. A promising solution is the adoption of bioelectrochemical systems. They guarantee a permanent electron supply and withdrawal for microorganisms, thereby circumventing the traditional shortcomings of bioremediation. These systems combine biological treatment with electrochemical oxidation/reduction by supplying an anode and a cathode that serve as an electron exchange facility for the biocatalyst. Here, recent achievements in polycyclic aromatic hydrocarbon removal using bioelectrochemical systems have been reviewed. This also concerns PAH precursors: total petroleum hydrocarbons and diesel. Removal performances of PAH biodegradation in bioelectrochemical systems are discussed, focussing on configurational parameters such as anode and cathode designs as well as environmental parameters like porosity, salinity, adsorption and conductivity of soil and sediment that affect PAH biodegradation in BESs. The still scarcely available information on microbiological aspects of bioelectrochemical PAH removal is summarised here. This comprehensive review offers a better understanding of the parameters that affect the removal of PAHs within bioelectrochemical systems. In addition, future experimental setups are proposed in order to study syntrophic relationships between PAH degraders and exoelectrogens. This synopsis can help as guide for researchers in their choices for future experimental designs aiming at increasing the power densities and PAH biodegradation rates using microbial bioelectrochemistry. Copyright © 2017 Elsevier Ltd. All rights reserved.

Iron-Dependent Enzyme Catalyzes the Initial Step in Biodegradation of N -Nitroglycine by Variovorax sp. Strain JS1663

DOE Office of Scientific and Technical Information (OSTI.GOV)

Mahan, Kristina M.; Zheng, Hangping; Fida, Tekle T.

Nitramines are key constituents of most of the explosives currently in use and consequently contaminate soil and groundwater at many military facilities around the world. Toxicity from nitramine contamination poses a health risk to plants and animals. Thus, understanding how nitramines are biodegraded is critical to environmental remediation. The biodegradation of synthetic nitramine compounds such as hexahydro-1,3,5-trinitro-1,3,5-triazine (RDX) has been studied for decades, but little is known about the catabolism of naturally produced nitramine compounds. Here in this study, we report the isolation of a soil bacterium, Variovorax sp. strain JS1663, that degrades N-nitroglycine (NNG), a naturally produced nitramine, andmore » the key enzyme involved in its catabolism. Variovorax sp. JS1663 is a Gram-negative, non-spore-forming motile bacterium isolated from activated sludge based on its ability to use NNG as a sole growth substrate under aerobic conditions. A single gene (nnlA) encodes an iron-dependent enzyme that releases nitrite from NNG through a proposed β-elimination reaction. Bioinformatics analysis of the amino acid sequence of NNG lyase identified a PAS (Per-Arnt-Sim) domain. PAS domains can be associated with heme cofactors and function as signal sensors in signaling proteins. Finally, this is the first instance of a PAS domain present in a denitration enzyme. The NNG biodegradation pathway should provide the basis for the identification of other enzymes that cleave the N—N bond and facilitate the development of enzymes to cleave similar bonds in RDX, nitroguanidine, and other nitramine explosives.« less

Survey of the Anaerobic Biodegradation Potential of Organic Chemicals in Digesting Sludge

PubMed Central

Battersby, Nigel S.; Wilson, Valerie

1989-01-01

The degradation potential of 77 organic chemicals under methanogenic conditions was examined with an anaerobic digesting sludge from the United Kingdom. Degradation was assessed in terms of net total gas (CH4 plus CO2) produced, expressed as a percentage of the theoretical production (ThGP). The compounds tested were selected from various chemical groups and included substituted phenols and benzoates, pesticides, phthalic acid esters, homocyclic and heterocyclic ring compounds, glycols, and monosubstituted benzenes. The results obtained were in good agreement with published surveys of biodegradability in U.S. digesting sludges and other methanogenic environments. In general, the presence of chloro or nitro groups inhibited anaerobic gas production, while carboxyl and hydroxyl groups facilitated biodegradation. The relationship between substituent position and susceptibility to methanogenic degradation was compound dependent. The following chemicals were completely degraded (≥80% ThGP) at a concentration of 50 mg of carbon per liter: phenol, 2-aminophenol, 4-cresol, catechol, sodium benzoate, 4-aminobenzoic acid, 3-chlorobenzoic acid, phthalic acid, ethylene glycol, diethylene glycol, triethylene glycol, sodium stearate, and quinoline. 3-Cresol, 4-chlorobenzoic acid, dimethyl phthalate, and pyridine were partially degraded. Although the remaining chemicals tested were either persistent or toxic, their behavior may differ at more environmentally realistic chemical-to-biomass ratios. Our findings suggest that biodegradability assessments made with sludge from one source can be extrapolated to sludge from another source with a reasonable degree of confidence and should help in predicting the fate of an organic chemical during the anaerobic digestion of sewage sludge. PMID:16347851

Iron-Dependent Enzyme Catalyzes the Initial Step in Biodegradation of N -Nitroglycine by Variovorax sp. Strain JS1663

DOE PAGES

Mahan, Kristina M.; Zheng, Hangping; Fida, Tekle T.; ...

2017-05-19

Nitramines are key constituents of most of the explosives currently in use and consequently contaminate soil and groundwater at many military facilities around the world. Toxicity from nitramine contamination poses a health risk to plants and animals. Thus, understanding how nitramines are biodegraded is critical to environmental remediation. The biodegradation of synthetic nitramine compounds such as hexahydro-1,3,5-trinitro-1,3,5-triazine (RDX) has been studied for decades, but little is known about the catabolism of naturally produced nitramine compounds. Here in this study, we report the isolation of a soil bacterium, Variovorax sp. strain JS1663, that degrades N-nitroglycine (NNG), a naturally produced nitramine, andmore » the key enzyme involved in its catabolism. Variovorax sp. JS1663 is a Gram-negative, non-spore-forming motile bacterium isolated from activated sludge based on its ability to use NNG as a sole growth substrate under aerobic conditions. A single gene (nnlA) encodes an iron-dependent enzyme that releases nitrite from NNG through a proposed β-elimination reaction. Bioinformatics analysis of the amino acid sequence of NNG lyase identified a PAS (Per-Arnt-Sim) domain. PAS domains can be associated with heme cofactors and function as signal sensors in signaling proteins. Finally, this is the first instance of a PAS domain present in a denitration enzyme. The NNG biodegradation pathway should provide the basis for the identification of other enzymes that cleave the N—N bond and facilitate the development of enzymes to cleave similar bonds in RDX, nitroguanidine, and other nitramine explosives.« less

Degradation of Carbazole by Microbial Cells Immobilized in Magnetic Gellan Gum Gel Beads▿

PubMed Central

Wang, Xia; Gai, Zhonghui; Yu, Bo; Feng, Jinhui; Xu, Changyong; Yuan, Yong; Lin, Zhixin; Xu, Ping

2007-01-01

Polycyclic aromatic heterocycles, such as carbazole, are environmental contaminants suspected of posing human health risks. In this study, we investigated the degradation of carbazole by immobilized Sphingomonas sp. strain XLDN2-5 cells. Four kinds of polymers were evaluated as immobilization supports for Sphingomonas sp. strain XLDN2-5. After comparison with agar, alginate, and κ-carrageenan, gellan gum was selected as the optimal immobilization support. Furthermore, Fe3O4 nanoparticles were prepared by a coprecipitation method, and the average particle size was about 20 nm with 49.65-electromagnetic-unit (emu) g−1 saturation magnetization. When the mixture of gellan gel and the Fe3O4 nanoparticles served as an immobilization support, the magnetically immobilized cells were prepared by an ionotropic method. The biodegradation experiments were carried out by employing free cells, nonmagnetically immobilized cells, and magnetically immobilized cells in aqueous phase. The results showed that the magnetically immobilized cells presented higher carbazole biodegradation activity than nonmagnetically immobilized cells and free cells. The highest biodegradation activity was obtained when the concentration of Fe3O4 nanoparticles was 9 mg ml−1 and the saturation magnetization of magnetically immobilized cells was 11.08 emu g−1. Additionally, the recycling experiments demonstrated that the degradation activity of magnetically immobilized cells increased gradually during the eight recycles. These results support developing efficient biocatalysts using magnetically immobilized cells and provide a promising technique for improving biocatalysts used in the biodegradation of not only carbazole, but also other hazardous organic compounds. PMID:17827304

Impact of hydrocarbon type, concentration and weathering on its biodegradability in soil.

PubMed

Maletić, Snežana P; Dalmacija, Božo D; Rončević, Srđan D; Agbaba, Jasmina R; Perović, Svetlana D Ugarčina

2011-01-01

The objective of this research was to investigate the impact of the hydrocarbon type and concentration, as well as the total effect of the natural weathering process to hydrocarbon biodegradability in sandy soil and the environment. In this experiment, sandy soil was separately contaminated with 0.5%, 1.0%, 2.0% and 3.5% of diesel and crude oils. Oil contaminated soil was taken from the Oil Refinery dumping sites after 9 years of weathering, and its concentration was adjusted to the above-mentioned levels. The biodegradation process was monitored by measuring CO(2), evolution rate, hydrocarbon degradation rate and dehydrogenase activity. The favourable concentration ranges for the soil contaminated with diesel oil were 1.0%, with concentrations at about 2.0% causing slightly adverse effects to CO(2) production which was overcome after 2 weeks, and with 3.5% diesel oil causing significant toxicity. For soil contaminated with crude oil, 2.0% was found to be optimum for effective biodegradation, with 3.5% crude oil also causing adverse effects to CO(2) production, although less so than the same concentration of diesel oil. No adverse effect was obtained for any concentration of the weathered oil, as after the weathering process, the remaining contaminants in the soil were mostly poorly degradable constituents like asphaltenes, resins etc. It has been proposed that such residual material from oil degradation is analogous to, and can even be regarded as, humic material. Due to its inert characteristics, insolubility and similarity to humic materials it is unlikely to be environmentally hazardous.

Benz[a]anthracene Biotransformation and Production of Ring Fission Products by Sphingobium sp. Strain KK22

PubMed Central

Kunihiro, Marie; Ozeki, Yasuhiro; Nogi, Yuichi; Hamamura, Natsuko

2013-01-01

A soil bacterium, designated strain KK22, was isolated from a phenanthrene enrichment culture of a bacterial consortium that grew on diesel fuel, and it was found to biotransform the persistent environmental pollutant and high-molecular-weight polycyclic aromatic hydrocarbon (PAH) benz[a]anthracene. Nearly complete sequencing of the 16S rRNA gene of strain KK22 and phylogenetic analysis revealed that this organism is a new member of the genus Sphingobium. An 8-day time course study that consisted of whole-culture extractions followed by high-performance liquid chromatography (HPLC) analyses with fluorescence detection showed that 80 to 90% biodegradation of 2.5 mg liter−1 benz[a]anthracene had occurred. Biodegradation assays where benz[a]anthracene was supplied in crystalline form (100 mg liter−1) confirmed biodegradation and showed that strain KK22 cells precultured on glucose were equally capable of benz[a]anthracene biotransformation when precultured on glucose plus phenanthrene. Analyses of organic extracts from benz[a]anthracene biodegradation by liquid chromatography negative electrospray ionization tandem mass spectrometry [LC/ESI(−)-MS/MS] revealed 10 products, including two o-hydroxypolyaromatic acids and two hydroxy-naphthoic acids. 1-Hydroxy-2- and 2-hydroxy-3-naphthoic acids were unambiguously identified, and this indicated that oxidation of the benz[a]anthracene molecule occurred via both the linear kata and angular kata ends of the molecule. Other two- and single-aromatic-ring metabolites were also documented, including 3-(2-carboxyvinyl)naphthalene-2-carboxylic acid and salicylic acid, and the proposed pathways for benz[a]anthracene biotransformation by a bacterium were extended. PMID:23686261

Biodegradation of phenol in batch and continuous flow microbial fuel cells with rod and granular graphite electrodes.

PubMed

Moreno, Lyman; Nemati, Mehdi; Predicala, Bernardo

2018-01-01

Phenol biodegradation was evaluated in batch and continuous flow microbial fuel cells (MFCs). In batch-operated MFCs, biodegradation of 100-1000 mg L -1 phenol was four to six times faster when graphite granules were used instead of rods (3.5-4.8 mg L -1  h -1 vs 0.5-0.9 mg L -1  h -1 ). Similarly maximum phenol biodegradation rates in continuous MFCs with granular and single-rod electrodes were 11.5 and 0.8 mg L -1  h -1 , respectively. This superior performance was also evident in terms of electrochemical outputs, whereby continuous flow MFCs with granular graphite electrodes achieved maximum current and power densities (3444.4 mA m -3 and 777.8 mW m -3 ) that were markedly higher than those with single-rod electrodes (37.3 mA m -3 and 0.8 mW m -3 ). Addition of neutral red enhanced the electrochemical outputs to 5714.3 mA m -3 and 1428.6 mW m -3 . Using the data generated in the continuous flow MFC, biokinetic parameters including μ m , K S , Y and K e were determined as 0.03 h -1 , 24.2 mg L -1 , 0.25 mg cell (mg phenol) -1 and 3.7 × 10 -4  h -1 , respectively. Access to detailed kinetic information generated in MFC environmental conditions is critical in the design, operation and control of large-scale treatment systems utilizing MFC technology.

IN-SITU AIR INJECTION, SOIL VACUUM EXTRACTION AND ENHANCED BIODEGRADATION: A CASE STUDY IN A JP-4 JET FUEL CONTAMINATED SITE

EPA Science Inventory

The U.S. Environmental Protection Agency (U.S. EPA) and the U.S. Coast Guard (USCG) conducted a joint demonstration of in situ remediation of a JP-4 jet fuel spill at the USCG Support Center in Elizabeth City, North Carolina. The jet fuel was trapped beneath a clay layer that ext...

Environmental Fate and Effects of Organotin Biocides: A Molecular and Microbiological Assessment.

DTIC Science & Technology

1986-12-12

GROUP__ biocides, antifouling compounds, environment, tributyltin , 08 organotin, tin, standards, biodegradation, organometals !9.\\ASTRACT (Continue on...and effects of the toxic tributyltin species, an active agent in new ship antifouling coatings. -44-4eiped- vltratrace’butyltin measurement’ ehdl c d...Standards Gaithersburg, MD 20899 Introduction New tributyltin -based antifouling paints, some types already widely used in the private sector, offer

Dynamic modeling of environmental risk associated with drilling discharges to marine sediments.

PubMed

Durgut, İsmail; Rye, Henrik; Reed, Mark; Smit, Mathijs G D; Ditlevsen, May Kristin

2015-10-15

Drilling discharges are complex mixtures of base-fluids, chemicals and particulates, and may, after discharge to the marine environment, result in adverse effects on benthic communities. A numerical model was developed to estimate the fate of drilling discharges in the marine environment, and associated environmental risks. Environmental risk from deposited drilling waste in marine sediments is generally caused by four types of stressors: oxygen depletion, toxicity, burial and change of grain size. In order to properly model these stressors, natural burial, biodegradation and bioturbation processes were also included. Diagenetic equations provide the basis for quantifying environmental risk. These equations are solved numerically by an implicit-central differencing scheme. The sediment model described here is, together with a fate and risk model focusing on the water column, implemented in the DREAM and OSCAR models, both available within the Marine Environmental Modeling Workbench (MEMW) at SINTEF in Trondheim, Norway. Copyright © 2015 Elsevier Ltd. All rights reserved.

Review on the Extraction Methods of Crude oil from all Generation Biofuels in last few Decades

NASA Astrophysics Data System (ADS)

Bhargavi, G.; Nageswara Rao, P.; Renganathan, S.

2018-03-01

The ever growing demand for the energy fuels, economy of oil, depletion of energy resources and environmental protection are the inevitable challenges required to be solved meticulously in future decades in order to sustain the life of humans and other creatures. Switching to alternate fuels that are renewable, biodegradable, economically and environmentally friendly can quench the minimum thirst of fuel demands, in addition to mitigation of climate changes. At this moment, production of biofuels has got prominence. The term biofuels broadly refer to the fuels derived from living matter either animals or plants. Among the competent biofuels, biodiesel is one of the promising alternates for diesel engines. Biodiesel is renewable, environmentally friendly, safe to use with wide applications and biodegradable. Due to which, it has become a major focus of intensive global research and development of alternate energy. The present review has been focused specifically on biodiesel. Concerning to the biodiesel production, the major steps includes lipid extraction followed by esterification/transesterification. For the extraction of lipids, several extraction techniques have been put forward irrespective of the generations and feed stocks used. This review provides theoretical background on the two major extraction methods, mechanical and chemical extraction methods. The practical issues of each extraction method such as efficiency of extraction, extraction time, oil sources and its pros and cons are discussed. It is conceived that congregating information on oil extraction methods may helpful in further research advancements to ease biofuel production.

Aerobic biodegradation of a nonylphenol polyethoxylate and toxicity of the biodegradation metabolites.

PubMed

Jurado, Encarnación; Fernández-Serrano, Mercedes; Núñez-Olea, Josefa; Lechuga, Manuela

2009-09-01

In this paper a study was made of the biodegradation of a non-ionic surfactant, a nonylphenol polyethoxylate, in biodegradability tests by monitoring the residual surfactant matter. The influence of the concentration on the extent of primary biodegradation, the toxicity of biodegradation metabolites, and the kinetics of degradation were also determined. The primary biodegradation was studied at different initial concentrations: 5, 25 and 50 mg/L, (at sub-and supra-critical micelle concentration). The NPEO used in this study can be considered biodegradable since the primary biodegradation had already taken place (a biodegradation greater than 80% was found for the different initial concentration tested). The initial concentration affected the shape of the resulting curve, the mean biodegradation rate and the percentage of biodegradation reached (99% in less than 8 days at 5 mg/L, 98% in less than 13 days at 25 mg/L and 95% in 14 days at 50 mg/L). The kinetic model of Quiroga and Sales (1991) was applied to predict the biodegradation of the NPEO. The toxicity value was measured as EC(20) and EC(50). In addition, during the biodegradation process of the surfactant a toxicity analysis was made of the evolution of metabolites generated, confirming that the subproducts of the biodegradation process were more toxic than the original.

Novel Sustainable Composites Based on Poly(hydroxybutyrate-co-hydroxyvalerate) and Seagrass Beach-CAST Fibers: Performance and Degradability in Marine Environments.

PubMed

Seggiani, Maurizia; Cinelli, Patrizia; Balestri, Elena; Mallegni, Norma; Stefanelli, Eleonora; Rossi, Alessia; Lardicci, Claudio; Lazzeri, Andrea

2018-05-11

In order to produce sustainable, bio-based and highly biodegradable materials, composites based on poly(hydroxybutyrate-co-hydroxyvalerate) (PHBV) and fibers of Posidonia oceanica (PO), a dominant Mediterranean seagrass, were produced by simple melt mixing and characterized in terms of thermal stability, morphology and rheological/mechanical properties. In view of their potential application in marine environments, degradation of the developed composites was evaluated under simulated and real marine environmental conditions for 1 year. Using 10 wt % of acetyl tributyl citrate (ATBC) as a plasticizer, smooth processing was achieved for up to 30 wt % of PO fibers, despite the reduction of the melt fluidity observed with increasing fiber loading. The tensile modulus slightly increased (from 2 to 2.4 GPa) while the tensile strength and the elongation decreased (from 23.6 to 21.5 MPa and from 3.2 to 1.9%, respectively) by increasing the PO fiber content from 0 to 30 wt %. Interestingly, the impact resistance of the composites increased with the increasing of the PO content: the Charpy’s impact energy increased from 3.6 (without fiber) to 4.4 kJ/m² for the composite with 30 wt %. The results of the aerobic biodegradation under simulated marine conditions showed that the presence of PO fibers favored the physical disintegration of the composite increasing the biodegradation rate of the polymeric matrix: after 216 days, the composite with 20 wt % PO fibers showed a biodegradability of about 30% compared to 20% of the composite without fibers. Under real marine conditions, the specimens containing PO fibers showed higher weight losses and deterioration of tensile properties compared to those without fibers. Presumably, biodegradation occurred after colonization of the specimen, and the specimens with 20 wt % PO fibers showed well-developed biofilm consisting of bacteria and fungi on the surface after only 3 months of incubation in marine sediments, unlike the no-fiber specimens. Consequently, the persistence of an adequate mechanical performance for a relatively long period (1 year), due to a moderate rate of biodegradation in the marine environment, make the developed PHBV/PO composites particularly suitable for the production of relatively low-cost and biodegradable items which are usable in the sea and/or sand dunes, increasing the market opportunities for biopolymers such as PHBV and, at the same time, finding an eco-sustainable valorization for the PO fibrous residues accumulated in large quantities on Mediterranean beaches, which represents a problem for coastal municipalities.

Novel Sustainable Composites Based on Poly(hydroxybutyrate-co-hydroxyvalerate) and Seagrass Beach-CAST Fibers: Performance and Degradability in Marine Environments

PubMed Central

Mallegni, Norma; Stefanelli, Eleonora; Rossi, Alessia

2018-01-01

In order to produce sustainable, bio-based and highly biodegradable materials, composites based on poly(hydroxybutyrate-co-hydroxyvalerate) (PHBV) and fibers of Posidonia oceanica (PO), a dominant Mediterranean seagrass, were produced by simple melt mixing and characterized in terms of thermal stability, morphology and rheological/mechanical properties. In view of their potential application in marine environments, degradation of the developed composites was evaluated under simulated and real marine environmental conditions for 1 year. Using 10 wt % of acetyl tributyl citrate (ATBC) as a plasticizer, smooth processing was achieved for up to 30 wt % of PO fibers, despite the reduction of the melt fluidity observed with increasing fiber loading. The tensile modulus slightly increased (from 2 to 2.4 GPa) while the tensile strength and the elongation decreased (from 23.6 to 21.5 MPa and from 3.2 to 1.9%, respectively) by increasing the PO fiber content from 0 to 30 wt %. Interestingly, the impact resistance of the composites increased with the increasing of the PO content: the Charpy’s impact energy increased from 3.6 (without fiber) to 4.4 kJ/m2 for the composite with 30 wt %. The results of the aerobic biodegradation under simulated marine conditions showed that the presence of PO fibers favored the physical disintegration of the composite increasing the biodegradation rate of the polymeric matrix: after 216 days, the composite with 20 wt % PO fibers showed a biodegradability of about 30% compared to 20% of the composite without fibers. Under real marine conditions, the specimens containing PO fibers showed higher weight losses and deterioration of tensile properties compared to those without fibers. Presumably, biodegradation occurred after colonization of the specimen, and the specimens with 20 wt % PO fibers showed well-developed biofilm consisting of bacteria and fungi on the surface after only 3 months of incubation in marine sediments, unlike the no-fiber specimens. Consequently, the persistence of an adequate mechanical performance for a relatively long period (1 year), due to a moderate rate of biodegradation in the marine environment, make the developed PHBV/PO composites particularly suitable for the production of relatively low-cost and biodegradable items which are usable in the sea and/or sand dunes, increasing the market opportunities for biopolymers such as PHBV and, at the same time, finding an eco-sustainable valorization for the PO fibrous residues accumulated in large quantities on Mediterranean beaches, which represents a problem for coastal municipalities. PMID:29751601

Environmental impact of rejected materials generated in organic fraction of municipal solid waste anaerobic digestion plants: Comparison of wet and dry process layout.

PubMed

Colazo, Ana-Belén; Sánchez, Antoni; Font, Xavier; Colón, Joan

2015-09-01

Anaerobic digestion of source separated organic fraction of municipal solid waste is an increasing waste valorization alternative instead of incineration or landfilling of untreated biodegradable wastes. Nevertheless, a significant portion of biodegradable wastes entering the plant is lost in pre-treatments and post-treatments of anaerobic digestion facilities together with other improper materials such as plastics, paper, textile materials and metals. The rejected materials lost in these stages have two main implications: (i) less organic material enters to digesters and, as a consequence, there is a loss of biogas production and (ii) the rejected materials end up in landfills or incinerators contributing to environmental impacts such as global warming or eutrophication. The main goals of this study are (i) to estimate potential losses of biogas in the rejected solid materials generated during the pre- and post-treatments of two full-scale anaerobic digestion facilities and (ii) to evaluate the environmental burdens associated to the final disposal (landfill or incineration) of these rejected materials by means of Life Cycle Assessment. This study shows that there is a lost of potential biogas production, ranging from 8% to 15%, due to the loss of organic matter during pre-treatment stages in anaerobic digestion facilities. From an environmental point of view, the Life Cycle Assessment shows that the incineration scenario is the most favorable alternative for eight out of nine impact categories compared with the landfill scenario. The studied impact categories are Climate Change, Fossil depletion, Freshwater eutrophication, Marine eutrophication, Ozone depletion, Particulate matter formation, Photochemical oxidant formation, Terrestrial acidification and Water depletion. Copyright © 2015 Elsevier Ltd. All rights reserved.

Study of the photodegradation of a fragrance ingredient for aquatic environmental fate assessment.

PubMed

Lin, Jianming; Emberger, Matthew

2017-04-01

Photodegradation is an important abiotic degradation process to be taken into account for more accurate assessment of the fate of chemicals in the aquatic environment, especially those that are not readily biodegradable. Although the significant role of indirect photodegradation in the environmental fate of chemicals has been revealed in recent research, because of the many confounding factors affecting its kinetics, no straightforward approaches can be used to investigate this degradation process for environmental fate assessment. The indirect photodegradation of a fragrance ingredient named Pamplewood was studied in this work for its fate assessment. Indirect photodegradation rates under various indoor and outdoor conditions were measured by using an LC-MS method. Although the half-lives varied from 4 to 13 days, they collectively indicated that Pamplewood is intrinsically photolabile and can undergo rapid photodegradation. Results from quencher experiments revealed that ⋅OH was the main reactive intermediate responsible for indirect photodegradation, with a half-life of about 18 days in sunlit surface water, based on the experimentally determined second-order rate constant (8.48 ± 0.19 × 10 9  M -1  s -1 ). Photodegradation products of Pamplewood were also studied by GC-MS, LC-MS and total organic carbon content analyses. The results indicated that intermediates of Pamplewood photodegradation continued to photodegrade into smaller and more polar species. Complete mineralization of Pamplewood was observed when it was reacted with hydroxyl radicals in an aqueous solution. This novel approach can be applied for a more realistic environmental fate assessment of other non-readily biodegradable, hydrolysis-resistant, and non-sunlight-absorbing fragrance ingredients. Copyright © 2017 Elsevier Ltd. All rights reserved.

Biosurfactant Production by Bacillus salmalaya for Lubricating Oil Solubilization and Biodegradation.

PubMed

Dadrasnia, Arezoo; Ismail, Salmah

2015-08-19

This study investigated the capability of a biosurfactant produced by a novel strain of Bacillus salmalaya to enhance the biodegradation rates and bioavailability of organic contaminants. The biosurfactant produced by cultured strain 139SI showed high physicochemical properties and surface activity in the selected medium. The biosurfactant exhibited a high emulsification index and a positive result in the drop collapse test, with the results demonstrating the wetting activity of the biosurfactant and its potential to produce surface-active molecules. Strain 139SI can significantly reduce the surface tension (ST) from 70.5 to 27 mN/m, with a critical micelle concentration of 0.4%. Moreover, lubricating oil at 2% (v/v) was degraded on Day 20 (71.5). Furthermore, the biosurfactant demonstrated high stability at different ranges of salinity, pH, and temperature. Overall, the results indicated the potential use of B. salmalaya 139SI in environmental remediation processes.

Behavior of metalaxyl and its pure R-enantiomer in sunflower plants (Helianthus annus).

PubMed

Zadra, C; Marucchini, C; Zazzerini, A

2002-09-11

A possible stereospecific and/or stereoselective mechanism of biodegradation for metalaxyl and metalaxyl-M was studied to elucidate their behavior in sunflower plants and to compare their biodegradation. Greenhouse experiments were carried out to confirm the same efficacy of the two fungicides against infections by Plasmopara helianthi in sunflower plants. The two fungicides appear to have the same behavior regarding both the protection against plant infections and the mode of translocation and the rate and pathway of biotransformation, but we have evidence that this biotransformation process is enantioselective. Furthermore, we propose procedures for a chromatographic separation of enantiomers and acid metabolites of the fungicides and for the determination of the R:S ratio by HPLC chiral analyses. This study emphasizes the importance of examining the fate of both stereoisomers of a chiral agrochemical in an environmental system for the correct use of enantiomerically pure agrochemical compounds.

The capacity of some newly bacteria and fungi for biodegradation of herbicide trifluralin under agiated culture media.

PubMed

Erguven, G O; Bayhan, H; Ikizoglu, B; Kanat, G; Nuhoglu, Y

2016-05-30

Bioremediation is the use of microorganisms to degrade environmental contaminants (pesticides, polyaromatic hydrocarbons etc.) into less toxic forms or compounds. In this study microbial biodegradation of trifluralin was performed in liquid media with 11 different types of identified fungi and bacteria cultures and their mixtures in agiated culture media. The isolated fungi and bacteria mixtures showed the highest degradation, reaching 93% in the chemical oxygen demand (COD) parameter in four days and 82% as trifluralin active ingredient in five days. Bacteria and fungi mixtures achieved 69% and 66% degradations of trifluralin active ingredient respectively. In the fungi studies, the best removal was achieved by M.Chlamydosporia at 80%, in the bacteria studies, the best removal was achieved by Bacillus simplex about 95% in five days. These different removal rates were due to the microbial differencies.

An Excel®-based visualization tool of 2-D soil gas concentration profiles in petroleum vapor intrusion

PubMed Central

Verginelli, Iason; Yao, Yijun; Suuberg, Eric M.

2017-01-01

In this study we present a petroleum vapor intrusion tool implemented in Microsoft® Excel® using Visual Basic for Applications (VBA) and integrated within a graphical interface. The latter helps users easily visualize two-dimensional soil gas concentration profiles and indoor concentrations as a function of site-specific conditions such as source strength and depth, biodegradation reaction rate constant, soil characteristics and building features. This tool is based on a two-dimensional explicit analytical model that combines steady-state diffusion-dominated vapor transport in a homogeneous soil with a piecewise first-order aerobic biodegradation model, in which rate is limited by oxygen availability. As recommended in the recently released United States Environmental Protection Agency's final Petroleum Vapor Intrusion guidance, a sensitivity analysis and a simplified Monte Carlo uncertainty analysis are also included in the spreadsheet. PMID:28163564

An Excel®-based visualization tool of 2-D soil gas concentration profiles in petroleum vapor intrusion.

PubMed

Verginelli, Iason; Yao, Yijun; Suuberg, Eric M

2016-01-01

In this study we present a petroleum vapor intrusion tool implemented in Microsoft ® Excel ® using Visual Basic for Applications (VBA) and integrated within a graphical interface. The latter helps users easily visualize two-dimensional soil gas concentration profiles and indoor concentrations as a function of site-specific conditions such as source strength and depth, biodegradation reaction rate constant, soil characteristics and building features. This tool is based on a two-dimensional explicit analytical model that combines steady-state diffusion-dominated vapor transport in a homogeneous soil with a piecewise first-order aerobic biodegradation model, in which rate is limited by oxygen availability. As recommended in the recently released United States Environmental Protection Agency's final Petroleum Vapor Intrusion guidance, a sensitivity analysis and a simplified Monte Carlo uncertainty analysis are also included in the spreadsheet.

Choline-based ionic liquids-enhanced biodegradation of azo dyes.

PubMed

Sekar, Sudharshan; Surianarayanan, Mahadevan; Ranganathan, Vijayaraghavan; MacFarlane, Douglas R; Mandal, Asit Baran

2012-05-01

Industrial wastewaters such as tannery and textile processing effluents are often characterized by a high content of dissolved organic dyes, resulting in large values of chemical and biological oxygen demand (COD and BOD) in the aquatic systems into which they are discharged. Such wastewater streams are of rapidly growing concern as a major environmental issue in developing countries. Hence there is a need to mitigate this challenge by effective approaches to degrade dye-contaminated wastewater. In this study, several choline-based salts originally developed for use as biocompatible hydrated ionic liquids (i.e., choline sacchrinate (CS), choline dihydrogen phosphate (CDP), choline lactate (CL), and choline tartarate (CT)) have been successfully employed as the cosubstrate with S. lentus in the biodegradation of an azo dye in aqueous solution. We also demonstrate that the azo dye has been degraded to less toxic components coupled with low biomass formation. © 2012 American Chemical Society

Effect of Aspergillus versicolor strain JASS1 on low density polyethylene degradation

NASA Astrophysics Data System (ADS)

Gajendiran, A.; Subramani, S.; Abraham, J.

2017-11-01

Low density polyethylene (LDPE) waste disposal remains one of the major environmental concerns faced by the world today. In past decades, major focus has been given to enhance the biodegradation of LDPE by microbial species. In this present study, Aspergillus versicolor with the ability to degrade LDPE was isolated from municipal landfill area using enrichment technique. Based on 18S rRNA gene sequencing confirmed its identity as Aspergillus versicolor. The biodegradation study was carried out for 90 d in M1 medium. The degradation behaviour of LDPE films by Aspergillus versicolor strain JASS1 were confirmed by weight loss, CO2 evolution, Scanning electron microscopy (SEM) analysis, Atomic force microscopy (AFM), Fourier transform infrared spectroscopy (FTIR) technique. From current investigation, it can be concluded that our isolated strain JASS1 had the potential to degrade LDPE films and it can be useful in solving the problem caused by polyethylene in the environment.

Identification of ester metabolites from petroleum hydrocarbon biodegradation in groundwater using GC×GC-TOFMS.

PubMed

O'Reilly, Kirk T; Mohler, Rachel E; Zemo, Dawn A; Ahn, Sungwoo; Tiwary, Asheesh K; Magaw, Renae I; Devine, Catalina Espino; Synowiec, Karen A

2015-09-01

In an effort to understand the nature and toxicity of petroleum hydrocarbon degradation metabolites, 2-dimensional gas chromatography linked to a time-of-flight mass spectrometer (GC×GC-TOFMS) was used to conduct nontargeted analysis of the extracts of 61 groundwater samples collected from 10 fuel release sites. An unexpected result was the tentative identification of 197 unique esters. Although esters are known to be part of specific hydrocarbon degradative pathways, they are not commonly considered or evaluated in field studies of petroleum biodegradation. In addition to describing the compounds identified, the present study discusses the role for nontargeted analysis in environmental studies. Overall, the low toxicological profile of the identified esters, along with the limited potential for exposure, renders them unlikely to pose any significant health risk. © 2015 The Authors. Published by Wiley Periodicals, Inc., on behalf of SETAC.

Innovative biological approaches for monitoring and improving water quality

PubMed Central

Aracic, Sanja; Manna, Sam; Petrovski, Steve; Wiltshire, Jennifer L.; Mann, Gülay; Franks, Ashley E.

2015-01-01

Water quality is largely influenced by the abundance and diversity of indigenous microbes present within an aquatic environment. Physical, chemical and biological contaminants from anthropogenic activities can accumulate in aquatic systems causing detrimental ecological consequences. Approaches exploiting microbial processes are now being utilized for the detection, and removal or reduction of contaminants. Contaminants can be identified and quantified in situ using microbial whole-cell biosensors, negating the need for water samples to be tested off-site. Similarly, the innate biodegradative processes can be enhanced through manipulation of the composition and/or function of the indigenous microbial communities present within the contaminated environments. Biological contaminants, such as detrimental/pathogenic bacteria, can be specifically targeted and reduced in number using bacteriophages. This mini-review discusses the potential application of whole-cell microbial biosensors for the detection of contaminants, the exploitation of microbial biodegradative processes for environmental restoration and the manipulation of microbial communities using phages. PMID:26322034

Environmentally friendly cellulose-based polyelectrolytes in wastewater treatment.

PubMed

Grenda, Kinga; Arnold, Julien; Gamelas, José A F; Rasteiro, Maria G

2017-09-01

Natural-based polyelectrolytes (PELs), with all the advantages coming from being produced from renewable and biodegradable sources, are a potential solution for the removal of dyes from wastewater. In this work, surplus Eucalyptus bleached cellulose fibres from a paper mill were modified to increase the charge and solubility of cellulose. First, reactive aldehyde groups were introduced in the cellulose backbone by periodate oxidation of cellulose. Further modification with alkylammonium produced positively charged cellulose-based PELs. The final products were characterized by several analytical techniques. The PEL with the highest substitution degree of cationic groups was evaluated for its performance in decolouration processes, bentonite being used as aid. This was found to be effective for colour removal of either anionic or cationic dyes. Bio-PELs can thus be considered as very favourable eco-friendly flocculation agents for decolouration of harsh effluents from several industries, considering their biodegradable nature and thus the ability to produce less sludge.

Thermo-mechanical behaviors of thermoplastic starch derived from sugar palm tree (Arenga pinnata).

PubMed

Sahari, J; Sapuan, S M; Zainudin, E S; Maleque, M A

2013-02-15

In recent years, increasing environmental concerns focused greater attention on the development of biodegradable materials. A thermoplastic starch derived from bioresources, sugar palm tree was successfully developed in the presence of biodegradable glycerol as a plasticizer. Sugar palm starch (SPS) was added with 15-40 w/w% of glycerol to prepare workable bioplastics and coded as SPS/G15, SPS/G20, SPS/G30 and SPS/G40. The samples were characterized for thermal properties, mechanical properties and moisture absorption on exposure to humidity were evaluated. Morphological studies through scanning electron microscopy (SEM) were used to explain the observed mechanical properties. Generally, the addition of glycerol decrease the transition temperature of plasticized SPS. The mechanical properties of plasticized SPS increase with the increasing of glycerol but up to 30 w/w%. Meanwhile, the water absorption of plasticized SPS decrease with increasing of glycerol. Copyright © 2012 Elsevier Ltd. All rights reserved.

Evaluation of copper slag to catalyze advanced oxidation processes for the removal of phenol in water.

PubMed

Huanosta-Gutiérrez, T; Dantas, Renato F; Ramírez-Zamora, R M; Esplugas, S

2012-04-30

The aim of this work was to evaluate the use of copper slag to catalyze phenol degradation in water by advanced oxidation processes (AOPs). Copper slag was tested in combination with H(2)O(2) (slag/H(2)O(2)) and H(2)O(2)/UV (slag/H(2)O(2)/UV). The studied methods promoted the complete photocatalytic degradation of phenol. Besides, they were able to reduce about 50% the TOC content in the samples. Slag/H(2)O(2)/UV and slag/H(2)O(2) treatments have favored biodegradability increment along the reaction time. Nevertheless, the irradiated method achieved higher values of the biodegradability indicator (BOD(5)/TOC). The toxicity assessment indicated the formation of more toxic compounds in both treatments. However, the control of the reaction time would minimize the environmental impact of the effluents. Copyright © 2012 Elsevier B.V. All rights reserved.

Biofiltration: an innovative air pollution control technology for VOC emissions.

PubMed

Leson, G; Winer, A M

1991-08-01

Biofiltration is a relatively recent air pollution control (APC) technology in which off-gases containing biodegradable volatile organic compounds (VOC) or inorganic air toxics are vented through a biologically active material. This technology has been successfully applied in Germany and The Netherlands in many full-scale applications to control odors, VOC and air toxic emissions from a wide range of industrial and public sector sources. Control efficiencies of more than 90 percent have been achieved for many common air pollutants. Due to lower operating costs, biofiltration can provide significant economic advantages over other APC technologies if applied to off-gases that contain readily biodegradable pollutants in low concentrations. Environmental benefits include low energy requirements and the avoidance of cross media transfer of pollutants. This paper reviews the history and current status of biofiltration, outlines its underlying scientific and engineering principles, and discusses the applicability of biofilters for a wide range of specific emission sources.

High throughput microencapsulation of Bacillus subtilis in semi-permeable biodegradable polymersomes for selenium remediation.

PubMed

Barlow, Jacob; Gozzi, Kevin; Kelley, Chase P; Geilich, Benjamin M; Webster, Thomas J; Chai, Yunrong; Sridhar, Srinivas; van de Ven, Anne L

2017-01-01

Encapsulating bacteria within constrained microenvironments can promote the manifestation of specialized behaviors. Using double-emulsion droplet-generating microfluidic synthesis, live Bacillus subtilis bacteria were encapsulated in a semi-permeable membrane composed of poly(ethylene glycol)-b-poly(D,L-lactic acid) (mPEG-PDLLA). This polymer membrane was sufficiently permeable to permit exponential bacterial growth, metabolite-induced gene expression, and rapid biofilm growth. The biodegradable microparticles retained structural integrity for several days and could be successfully degraded with time or sustained bacterial activity. Microencapsulated B. subtilis successfully captured and contained sodium selenite added outside the polymersomes, converting the selenite into elemental selenium nanoparticles that were selectively retained inside the polymer membrane. This remediation of selenium using polymersomes has high potential for reducing the toxicity of environmental selenium contamination, as well as allowing selenium to be harvested from areas not amenable to conventional waste or water treatment.

Treatment of petroleum hydrocarbon polluted environment through bioremediation: a review.

PubMed

Singh, Kriti; Chandra, Subhash

2014-01-01

Bioremediation play key role in the treatment of petroleum hydrocarbon contaminated environment. Exposure of petroleum hydrocarbon into the environment occurs either due to human activities or accidentally and cause environmental pollution. Petroleum hydrocarbon cause many toxic compounds which are potent immunotoxicants and carcinogenic to human being. Remedial methods for the treatment of petroleum contaminated environment include various physiochemical and biological methods. Due to the negative consequences caused by the physiochemical methods, the bioremediation technology is widely adapted and considered as one of the best technology for the treatment of petroleum contaminated environment. Bioremediation utilizes the natural ability of microorganism to degrade the hazardous compound into simpler and non hazardous form. This paper provides a review on the role of bioremediation in the treatment of petroleum contaminated environment, discuss various hazardous effects of petroleum hydrocarbon, various factors influencing biodegradation, role of various enzymes in biodegradation and genetic engineering in bioremediation.

New perspectives in plastic biodegradation.

PubMed

Sivan, Alex

2011-06-01

During the past 50 years new plastic materials, in various applications, have gradually replaced the traditional metal, wood, leather materials. Ironically, the most preferred property of plastics--durability--exerts also the major environmental threat. Recycling has practically failed to provide a safe solution for disposal of plastic waste (only 5% out of 1 trillion plastic bags, annually produced in the US alone, are being recycled). Since the most utilized plastic is polyethylene (PE; ca. 140 million tons/year), any reduction in the accumulation of PE waste alone would have a major impact on the overall reduction of the plastic waste in the environment. Since PE is considered to be practically inert, efforts were made to isolate unique microorganisms capable of utilizing synthetic polymers. Recent data showed that biodegradation of plastic waste with selected microbial strains became a viable solution. Copyright © 2011 Elsevier Ltd. All rights reserved.

Comparative Examination of the Olive Mill Wastewater Biodegradation Process by Various Wood-Rot Macrofungi

PubMed Central

Koutrotsios, Georgios; Zervakis, Georgios I.

2014-01-01

Olive mill wastewater (OMW) constitutes a major cause of environmental pollution in olive-oil producing regions. Sixty wood-rot macrofungi assigned in 43 species were evaluated for their efficacy to colonize solidified OMW media at initially established optimal growth temperatures. Subsequently eight strains of the following species were qualified: Abortiporus biennis, Ganoderma carnosum, Hapalopilus croceus, Hericium erinaceus, Irpex lacteus, Phanerochaete chrysosporium, Pleurotus djamor, and P. pulmonarius. Fungal growth in OMW (25%v/v in water) resulted in marked reduction of total phenolic content, which was significantly correlated with the effluent's decolorization. A. biennis was the best performing strain (it decreased phenolics by 92% and color by 64%) followed by P. djamor and I. lacteus. Increase of plant seeds germination was less pronounced evidencing that phenolics are only partly responsible for OMW's phytotoxicity. Laccase production was highly correlated with all three biodegradation parameters for H. croceus, Ph. chrysosporium, and Pleurotus spp., and so were manganese-independent and manganese dependent peroxidases for A. biennis and I. lacteus. Monitoring of enzymes with respect to biomass production indicated that Pleurotus spp., H. croceus, and Ph. chrysosporium shared common patterns for all three activities. Moreover, generation of enzymes at the early biodegradation stages enhanced the efficiency of OMW treatment. PMID:24987685

Co-concentration effect of silane with natural extract on biodegradable polymeric films for food packaging.

PubMed

Bashir, Anbreen; Jabeen, Sehrish; Gull, Nafisa; Islam, Atif; Sultan, Misbah; Ghaffar, Abdul; Khan, Shahzad Maqsood; Iqbal, Sadia Sagar; Jamil, Tahir

2018-01-01

Novel biodegradable films were prepared by blending guar gum, chitosan and poly (vinyl alcohol) having mint (ME) and grapefruit peel (GE) extracts and crosslinked with nontoxic tetraethoxysilane (TEOS). The co-concentration effect of TEOS with natural extracts on the films was studied. FTIR analysis confirmed the presence of incorporated components and the developed interactions among the polymer chains. The surface morphology of the films by SEM showed the hydrophilic character due to porous network structure. The films having both ME and GE with maximum amount of crosslinker (100μL), showed maximum swelling (58g/g) and stability while the optical properties showed increased protection against UV light. This film sample showed compact network structure which enhanced the ultimate tensile strength (40.03MPa) and elongation at break (104.8%). ME/GE conferred the antioxidant properties determined by radical scavenging activity and total phenolic contents (TPC) as ME films have greater TPC compared to GE films. The soil burial test exhibited the degradation of films rapidly (6days) confirming their strong microbial activity in soil. The lower water vapour transmission rate and water vapour permeability showed better shelf life; hence, these biodegradable films are environmental friendly and have potential for food and other packaging. Copyright © 2017 Elsevier B.V. All rights reserved.

Macrofouling communities and the degradation of plastic bags in the sea: an in situ experiment

PubMed Central

Petermann, Jana S.; Lott, Christian; Weber, Miriam

2017-01-01

The increasing amount of plastic littered into the sea may provide a new substratum for benthic organisms. These marine fouling communities on plastic have not received much scientific attention. We present, to our knowledge, the first comprehensive analysis of their macroscopic community composition, their primary production and the polymer degradation comparing conventional polyethylene (PE) and a biodegradable starch-based plastic blend in coastal benthic and pelagic habitats in the Mediterranean Sea. The biomass of the fouling layer increased significantly over time and all samples became heavy enough to sink to the seafloor. The fouling communities, consisting of 21 families, were distinct between habitats, but not between polymer types. Positive primary production was measured in the pelagic, but not in the benthic habitat, suggesting that large accumulations of floating plastic could pose a source of oxygen for local ecosystems, as well as a carbon sink. Contrary to PE, the biodegradable plastic showed a significant loss of tensile strength and disintegrated over time in both habitats. These results indicate that in the marine environment, biodegradable polymers may disintegrate at higher rates than conventional polymers. This should be considered for the development of new materials, environmental risk assessment and waste management strategies. PMID:29134070

Electrical resistivity tomography to monitor enhanced biodegradation of hydrocarbons with Rhodococcus erythropolis T902.1 at a pilot scale.

PubMed

Masy, Thibaut; Caterina, David; Tromme, Olivier; Lavigne, Benoît; Thonart, Philippe; Hiligsmann, Serge; Nguyen, Frédéric

2016-01-01

Petroleum hydrocarbons (HC) represent the most widespread contaminants and in-situ bioremediation remains a competitive treatment in terms of cost and environmental concerns. However, the efficiency of such a technique (by biostimulation or bioaugmentation) strongly depends on the environment affected and is still difficult to predict a priori. In order to overcome these uncertainties, Electrical Resistivity Tomography (ERT) appears as a valuable non-invasive tool to detect soil heterogeneities and to monitor biodegradation. The main objective of this study was to isolate an electrical signal linked to an enhanced bacterial activity with ERT, in an aged HC-contaminated clay loam soil. To achieve this, a pilot tank was built to mimic field conditions. Compared to a first insufficient biostimulation phase, bioaugmentation with Rhodococcus erythropolis T902.1 led to a HC depletion of almost 80% (6900 to 1600ppm) in 3months in the center of the contaminated zone, where pollutants were less bioavailable. In the meantime, lithological heterogeneities and microbial activities (growth and biosurfactant production) were successively discriminated by ERT images. In the future, this cost-effective technique should be more and more transferred to the field in order to monitor biodegradation processes and assist in selecting the most appropriate remediation technique. Copyright © 2015 Elsevier B.V. All rights reserved.

Monitoring Microbial Mineralization Using Reverse Stable Isotope Labeling Analysis by Mid-Infrared Laser Spectroscopy

PubMed Central

2017-01-01

Assessing the biodegradation of organic compounds is a frequent question in environmental science. Here, we present a sensitive, inexpensive, and simple approach to monitor microbial mineralization using reverse stable isotope labeling analysis (RIL) of dissolved inorganic carbon (DIC). The medium for the biodegradation assay contains regular organic compounds and 13C-labeled DIC with 13C atom fractions (x(13C)DIC) higher than natural abundance (typically 2–50%). The produced CO2 (x(13C) ≈ 1.11%) gradually dilutes the initial x(13C)DIC allowing to quantify microbial mineralization using mass-balance calculations. For 13C-enriched CO2 samples, a newly developed isotope ratio mid-infrared spectrometer was introduced with a precision of x(13C) < 0.006%. As an example for extremely difficult and slowly degradable compounds, CO2 production was close to the theoretical stoichiometry for anaerobic naphthalene degradation by a sulfate-reducing enrichment culture. Furthermore, we could measure the aerobic degradation of dissolved organic carbon (DOC) adsorbed to granular activated carbon in a drinking water production plant, which cannot be labeled with 13C. Thus, the RIL approach can be applied to sensitively monitor biodegradation of various organic compounds under anoxic or oxic conditions. PMID:28903553

Evaluation of toxicity and biodegradability of choline chloride based deep eutectic solvents.

PubMed

Radošević, Kristina; Bubalo, Marina Cvjetko; Srček, Višnje Gaurina; Grgas, Dijana; Dragičević, Tibela Landeka; Redovniković, Ivana Radojčić

2015-02-01

Deep eutectic solvents (DESs) have been dramatically expanding in popularity as a new generation of environmentally friendly solvents with possible applications in various industrial fields, but their ecological footprint has not yet been thoroughly investigated. In the present study, three choline chloride-based DESs with glucose, glycerol and oxalic acid as hydrogen bond donors were evaluated for in vitro toxicity using fish and human cell line, phytotoxicity using wheat and biodegradability using wastewater microorganisms through closed bottle test. Obtained in vitro toxicity data on cell lines indicate that choline chloride: glucose and choline chloride:glycerol possess low cytotoxicity (EC50>10 mM for both cell lines) while choline chloride:oxalic acid possess moderate cytotoxicity (EC50 value 1.64 mM and 4.19 mM for fish and human cell line, respectively). Results on phytotoxicity imply that tested DESs are non-toxic with seed germination EC50 values higher than 5000 mg L(-1). All tested DESs were classified as'readily biodegradable' based on their high levels of mineralization (68-96%). These findings indicate that DESs have a green profile and a good prospect for a wider use in the field of green technologies. Copyright © 2014 Elsevier Inc. All rights reserved.

Bioremediation of dyes by fungi isolated from contaminated dye effluent sites for bio-usability

PubMed Central

Rani, Babita; Kumar, Vivek; Singh, Jagvijay; Bisht, Sandeep; Teotia, Priyanku; Sharma, Shivesh; Kela, Ritu

2014-01-01

Biodegradation and detoxification of dyes, Malachite green, Nigrosin and Basic fuchsin have been carried out using two fungal isolates Aspergillus niger, and Phanerochaete chrysosporium, isolated from dye effluent soil. Three methods were selected for biodegradation, viz. agar overlay and liquid media methods; stationary and shaking conditions at 25 °C. Aspergillus niger recorded maximum decolorization of the dye Basic fuchsin (81.85%) followed by Nigrosin (77.47%), Malachite green (72.77%) and dye mixture (33.08%) under shaking condition. Whereas, P. chrysosporium recorded decolorization to the maximum with the Nigrosin (90.15%) followed by Basic fuchsin (89.8%), Malachite green (83.25%) and mixture (78.4%). The selected fungal strains performed better under shaking conditions compared to stationary method; moreover the inoculation of fungus also brought the pH of the dye solutions to neutral from acidic. Seed germination bioassay study exhibited that when inoculated dye solutions were used, seed showed germination while uninoculated dyes inhibited germination even after four days of observation. Similarly, microbial growth was also inhibited by uninoculated dyes. The excellent performance of A. niger and P. chrysporium in the biodegradation of textile dyes of different chemical structures suggests and reinforces the potential of these fungi for environmental decontamination. PMID:25477943

Biodegradation of thermally treated low density polyethylene by fungus Rhizopus oryzae NS 5.

PubMed

Awasthi, Shraddha; Srivastava, Neha; Singh, Tripti; Tiwary, D; Mishra, Pradeep Kumar

2017-05-01

Polythene is considered as one of the important object used in daily life. Being versatile in nature and resistant to microbial attack, they effectively cause environmental pollution. In the present study, biodegradation of low-density polyethylene (LDPE) have been performed using fungal lab isolate Rhizopus oryzae NS5. Lab isolate fungal strain capable of adhering to LDPE surface was used for the biodegradation of LDPE. This strain was identified as Rhizopus oryzae NS5 (Accession No. KT160362). Fungal growth was observed on the surface of the polyethylene when cultured in potato dextrose broth at 30 °C and 120 rpm, for 1 month. LDPE film was characterized before and after incubation by Fourier transform infrared spectroscopy, scanning electron microscopy, atomic force microscopy and universal tensile machine. About 8.4 ± 3% decrease (gravimetrically) in weight and 60% reduction in tensile strength of polyethylene was observed. Scanning electron microscope analysis showed hyphal penetration and degradation on the surface of polyethylene. Atomic force microscope analysis showed increased surface roughness after treatment with fungal isolate. A thick network of fungal hyphae forming a biofilm was also observed on the surface of the polyethylene pieces. Present study shows the potential of Rhizopus oryzae NS5 in polyethylene degradation in eco friendly and sustainable manner.

Whose butt is it? tobacco industry research about smokers and cigarette butt waste

PubMed Central

Novotny, Thomas E

2011-01-01

Background Cigarette filters are made of non-biodegradable cellulose acetate. As much as 766 571 metric tons of butts wind up as litter worldwide per year. Numerous proposals have been made to prevent or mitigate cigarette butt pollution, but none has been effective; cigarette butts are consistently found to be the single most collected item in beach clean-ups and litter surveys. Methods We searched the Legacy Tobacco Documents Library (http://legacy.library.ucsf.edu) and http://tobaccodocuments.org using a snowball strategy beginning with keywords (eg, ‘filter’, ‘biodegradable’, ‘butts’). Data from approximately 680 documents, dated 1959–2006, were analysed using an interpretive approach. Results The tobacco industry has feared being held responsible for cigarette litter for more than 20 years. Their efforts to avoid this responsibility included developing biodegradable filters, creating anti-litter campaigns, and distributing portable and permanent ashtrays. They concluded that biodegradable filters would probably encourage littering and would not be marketable, and that smokers were defensive about discarding their tobacco butts and not amenable to anti-litter efforts. Conclusions Tobacco control and environmental advocates should develop partnerships to compel the industry to take financial and practical responsibility for cigarette butt waste. PMID:21504919

Surfactant mediated enhanced biodegradation of hexachlorocyclohexane (HCH) isomers by Sphingomonas sp. NM05.

PubMed

Manickam, Natesan; Bajaj, Abhay; Saini, Harvinder S; Shanker, Rishi

2012-09-01

Environmental biodegradation of several chlorinated pesticides is limited by their low solubility and sorption to soil surfaces. To mitigate this problem we quantified the effect of three biosurfactant viz., rhamnolipid, sophorolipid and trehalose-containing lipid on the dissolution, bioavailability, and biodegradation of HCH-isomers in liquid culture and in contaminated soil. The effect of biosurfactants was evaluated through the critical micelle concentration (CMC) value as determined for each isomer. The surfactant increased the solubilization of HCH isomers by 3-9 folds with rhamnolipid and sophorolipid being more effective and showing maximum solubilization of HCH isomers at 40 μg/mL, compared to trehalose-containing lipid showing peak solubilization at 60 μg/mL. The degradation of HCH isomers by Sphingomonas sp. NM05 in surfactant-amended liquid mineral salts medium showed 30% enhancement in 2 days as compared to degradation in 10 days in the absence of surfactant. HCH-spiked soil slurry incubated with surfactant also showed around 30-50% enhanced degradation of HCH which was comparable to the corresponding batch culture experiments. Among the three surfactants, sophorolipid offered highest solubilization and enhanced degradation of HCH isomers both in liquid medium and soil culture. The results of this study suggest the effectiveness of surfactants in improving HCH degradation by increased bioaccessibility.

Impacts of discarded plastic bags on marine assemblages and ecosystem functioning.

PubMed

Green, Dannielle Senga; Boots, Bas; Blockley, David James; Rocha, Carlos; Thompson, Richard

2015-05-05

The accumulation of plastic debris is a global environmental problem due to its durability, persistence, and abundance. Although effects of plastic debris on individual marine organisms, particularly mammals and birds, have been extensively documented (e.g., entanglement and choking), very little is known about effects on assemblages and consequences for ecosystem functioning. In Europe, around 40% of the plastic items produced are utilized as single-use packaging, which rapidly accumulate in waste management facilities and as litter in the environment. A range of biodegradable plastics have been developed with the aspiration of reducing the persistence of litter; however, their impacts on marine assemblages or ecosystem functioning have never been evaluated. A field experiment was conducted to assess the impact of conventional and biodegradable plastic carrier bags as litter on benthic macro- and meio-faunal assemblages and biogeochemical processes (primary productivity, redox condition, organic matter content, and pore-water nutrients) on an intertidal shore near Dublin, Ireland. After 9 weeks, the presence of either type of bag created anoxic conditions within the sediment along with reduced primary productivity and organic matter and significantly lower abundances of infaunal invertebrates. This indicates that both conventional and biodegradable bags can rapidly alter marine assemblages and the ecosystem services they provide.

Electrical resistivity tomography to monitor enhanced biodegradation of hydrocarbons with Rhodococcus erythropolis T902.1 at a pilot scale

NASA Astrophysics Data System (ADS)

Masy, Thibaut; Caterina, David; Tromme, Olivier; Lavigne, Benoît; Thonart, Philippe; Hiligsmann, Serge; Nguyen, Frédéric

2016-01-01

Petroleum hydrocarbons (HC) represent the most widespread contaminants and in-situ bioremediation remains a competitive treatment in terms of cost and environmental concerns. However, the efficiency of such a technique (by biostimulation or bioaugmentation) strongly depends on the environment affected and is still difficult to predict a priori. In order to overcome these uncertainties, Electrical Resistivity Tomography (ERT) appears as a valuable non-invasive tool to detect soil heterogeneities and to monitor biodegradation. The main objective of this study was to isolate an electrical signal linked to an enhanced bacterial activity with ERT, in an aged HC-contaminated clay loam soil. To achieve this, a pilot tank was built to mimic field conditions. Compared to a first insufficient biostimulation phase, bioaugmentation with Rhodococcus erythropolis T902.1 led to a HC depletion of almost 80% (6900 to 1600 ppm) in 3 months in the center of the contaminated zone, where pollutants were less bioavailable. In the meantime, lithological heterogeneities and microbial activities (growth and biosurfactant production) were successively discriminated by ERT images. In the future, this cost-effective technique should be more and more transferred to the field in order to monitor biodegradation processes and assist in selecting the most appropriate remediation technique.

Biodegradability and biodegradation rate of poly(caprolactone)-starch blend and poly(butylene succinate) biodegradable polymer under aerobic and anaerobic environment.

PubMed

Cho, H S; Moon, H S; Kim, M; Nam, K; Kim, J Y

2011-03-01

The biodegradability and the biodegradation rate of two kinds biodegradable polymers; poly(caprolactone) (PCL)-starch blend and poly(butylene succinate) (PBS), were investigated under both aerobic and anaerobic conditions. PCL-starch blend was easily degraded, with 88% biodegradability in 44 days under aerobic conditions, and showed a biodegradation rate of 0.07 day(-1), whereas the biodegradability of PBS was only 31% in 80 days under the same conditions, with a biodegradation rate of 0.01 day(-1). Anaerobic bacteria degraded well PCL-starch blend (i.e., 83% biodegradability for 139 days); however, its biodegradation rate was relatively slow (6.1 mL CH(4)/g-VS day) compared to that of cellulose (13.5 mL CH(4)/g-VS day), which was used as a reference material. The PBS was barely degraded under anaerobic conditions, with only 2% biodegradability in 100 days. These results were consistent with the visual changes and FE-SEM images of the two biodegradable polymers after the landfill burial test, showing that only PCL-starch blend had various sized pinholes on the surface due to attack by microorganisms. This result may be use in deciding suitable final disposal approaches of different types of biodegradable polymers in the future. Copyright © 2010 Elsevier Ltd. All rights reserved.

The presence of insect at composting

NASA Astrophysics Data System (ADS)

Mudruňka, J.; Lyčková, B.; Kučerová, R.; Glogarová, V.; Závada, J.; Gibesová, B.; Takač, D.

2017-10-01

During composting biodegradable waste, microbic organisms reproduce massively, most of which belong to serious biopathogens which are able to penetrate various environmental layers. Their vector species include dipterous insect (Diptera) which reaches considerable amounts in composting plant premises as well as home composting units, mainly during summer months. Therefore measures must be taken to eliminate or reduce this unwanted phenomenon (sanitisation, disinfection). For evaluating obtained results, relative abundance calculation was chosen.

Environmental Restoration - Expedient Methods and Technologies: A User Guide with Case Studies

DTIC Science & Technology

1998-03-01

benzene, high fructose corn syrup , raw molasses, butane gas, sodium benzoate, or acetate. Enhanced anaerobic biodegradation of jet fuels in ground water...appendix discusses technology applications that are deemed impractical because of high cost, difficulty of use, or other factors. Also included is a...conversations with knowledgeable 1 Technologically sophisticated processes are not addressed in this study because of high cost, which includes the engineering

Research and Development of Methods for Estimating Physicochemical Properties of Organic Compounds of Environmental Concern

DTIC Science & Technology

1979-02-01

coefficient (at equilibrium) when hysteresis is apparent. 6. Coefficient n in Freundlich equation for 1/n soil or sediment adsorption isotherms ýX - KC . 7...Biodegradation Chemical structures cal clasaes (e.g., Diffusion Correlations phenols). General Diffusion coefficients Equations terms for organic...OF THE FATE AND TRANSPORT OF ORGANIC CHEMICALS Adsorption coefficients: K, n* from Freundlich equation + Desorption coefficients: K’*, n’* from

Prokaryotic cDNA Subtraction: A Method to Rapidly Identify Functional Gene Biomarkers

DTIC Science & Technology

2008-10-01

perchlorate-reducing bacteria (PRB) must not only be present, but they must also synthesize the enzymes that catalyze perchlorate reduction. The...synthesis of specific enzymes , termed gene expression, is often regulated by each cell in response to environmental conditions (e.g., influent water...diverse. MBT that target functional genes (e.g., genes that encode biodegradation enzymes ), might prove more useful for determining the capabilities of

Quantitative PCR for Tracking the Megaplasmid-Borne Biodegradation Potential of a Model Sphingomonad

PubMed Central

Hartmann, Erica M.; Badalamenti, Jonathan P.; Krajmalnik-Brown, Rosa

2012-01-01

We developed a quantitative PCR method for tracking the dxnA1 gene, the initial, megaplasmid-borne gene in Sphingomonas wittichii RW1's dibenzo-p-dioxin degradation pathway. We used this method on complex environmental samples and report on growth of S. wittichii RW1 in landfill leachate, thus furnishing a novel tool for monitoring megaplasmid-borne, dioxygenase-encoding genes. PMID:22492441

Elucidation of the Mechanisms and Environmental Relevance of cis-Dichloroethene and Vinyl Chloride Biodegradation

DTIC Science & Technology

2012-11-01

in iTRAQ study Table 3-12: Ratio of aldehyde and alcohol dehydrogenases from iTRAQ study Table 3-13: Proteins involved in proposed glyoxal...pathway for cDCE degradation proceeds through chloro-, or dichloroacetaldehyde. Multiple aldehyde dehydrogenases are annotated in the genome of...dichloroacetaldehyde is a fortuitous reaction. However, if the initial reaction is monooxygenation to an aldehyde then the true intermediate would be