Contamination detection NDE for cleaning process inspection

NASA Technical Reports Server (NTRS)

Marinelli, W. J.; Dicristina, V.; Sonnenfroh, D.; Blair, D.

1995-01-01

In the joining of multilayer materials, and in welding, the cleanliness of the joining surface may play a large role in the quality of the resulting bond. No non-intrusive techniques are currently available for the rapid measurement of contamination on large or irregularly shaped structures prior to the joining process. An innovative technique for the measurement of contaminant levels in these structures using laser based imaging is presented. The approach uses an ultraviolet excimer laser to illuminate large and/or irregular surface areas. The UV light induces fluorescence and is scattered from the contaminants. The illuminated area is viewed by an image-intensified CCD (charge coupled device) camera interfaced to a PC-based computer. The camera measures the fluorescence and/or scattering from the contaminants for comparison with established standards. Single shot measurements of contamination levels are possible. Hence, the technique may be used for on-line NDE testing during manufacturing processes.

In situ retreival of contaminants or other substances using a barrier system and leaching solutions and components, processes and methods relating thereto

DOEpatents

Nickelson, Reva A.; Walsh, Stephanie; Richardson, John G.; Dick, John R.; Sloan, Paul A.

2005-06-28

Processes and methods relating to treating contaminants and collecting desired substances from a zone of interest using subterranean collection and containment barriers. Tubular casings having interlock structures are used to create subterranean barriers for containing and treating buried waste and its effluents. The subterranean barrier includes an effluent collection system. Treatment solutions provided to the zone of interest pass therethrough and are collected by the barrier and treated or recovered, allowing on-site remediation. Barrier components may be used to in the treatment by collecting or removing contaminants or other materials from the zone of interest.

Development of a Screening Tool to Facilitate Technology Transfer of an Innovative Technology to Treat Perchlorate-Contaminated Water

DTIC Science & Technology

2008-03-01

foods such as fruits, vegetables, and beverages (U.S. FDA, 2004). If the U.S. EPA ultimately establishes a drinking water standard for perchlorate...TREAT PERCHLORATE-CONTAMINATED WATER THESIS Daniel A. Craig, Captain, USAF AFIT/GEM/ENV/08-M06 DEPARTMENT OF THE AIR FORCE AIR UNIVERSITY...OF AN INNOVATIVE TECHNOLOGY TO TREAT PERCHLORATE- CONTAMINATED WATER THESIS Presented to the Faculty Department of Systems and Engineering

Application of bacteriophages to reduce Salmonella contamination on workers' boots in rendering-processing environment.

PubMed

Gong, C; Jiang, X; Wang, J

2017-10-01

Workers' boots are considered one of the re-contamination routes of Salmonella for rendered meals in the rendering-processing environment. This study was conducted to evaluate the efficacy of a bacteriophage cocktail for reducing Salmonella on workers' boots and ultimately for preventing Salmonella re-contamination of rendered meals. Under laboratory conditions, biofilms of Salmonella Typhimurium avirulent strain 8243 formed on rubber templates or boots were treated with a bacteriophage cocktail of 6 strains (ca. 9 log PFU/mL) for 6 h at room temperature. Bacteriophage treatments combined with sodium hypochlorite (400 ppm) or 30-second brush scrubbing also were investigated for a synergistic effect on reducing Salmonella biofilms. Sodium magnesium (SM) buffer and sodium hypochlorite (400 ppm) were used as controls. To reduce indigenous Salmonella on workers' boots, a field study was conducted to apply a bacteriophage cocktail and other combined treatments 3 times within one wk in a rendering-processing environment. Prior to and after bacteriophage treatments, Salmonella populations on the soles of rubber boots were swabbed and enumerated on XLT-4, Miller-Mallinson or CHROMagar™ plates. Under laboratory conditions, Salmonella biofilms formed on rubber templates and boots were reduced by 95.1 to 99.999% and 91.5 to 99.2%, respectively. In a rendering-processing environment (ave. temperature: 19.3°C; ave. relative humidity: 48%), indigenous Salmonella populations on workers' boots were reduced by 84.2, 92.9, and 93.2% after being treated with bacteriophages alone, bacteriophages + sodium hypochlorite, and bacteriophages + scrubbing for one wk, respectively. Our results demonstrated the effectiveness of bacteriophage treatments in reducing Salmonella contamination on the boots in both laboratory and the rendering-processing environment. © 2017 Poultry Science Association Inc.

Coagulation-flocculation process applied to wastewaters generated in hydrocarbon-contaminated soil washing: Interactions among coagulant and flocculant concentrations and pH value.

PubMed

Torres, Luis G; Belloc, Claudia; Vaca, Mabel; Iturbe, Rosario; Bandala, Erick R

2009-11-01

Wastewater produced in the contaminated soil washing was treated by means of coagulation-flocculation (CF) process. The wastewater contained petroleum hydrocarbons, a surfactant, i.e., sodium dodecyl sulfate (SDS) as well as salts, brownish organic matter and other constituents that were lixiviated from the soil during the washing process. The main goal of this work was to develop a process for treating the wastewaters generated when washing hydrocarbon-contaminated soils in such a way that it could be recycled to the washing process, and also be disposed at the end of the process properly. A second objective was to study the relationship among the coagulant and flocculant doses and the pH at which the CF process is developed, for systems where methylene blue active substances (MBAS) as well as oil and greases were present. The results for the selection of the right coagulant and flocculant type and dose, the optimum pH value for the CF process and the interactions among the three parameters are detailed along this work. The best coagulant and flocculant were FeCl(3) and Tecnifloc 998 at doses of 4,000 and 1 mg/L, correspondingly at pH of 5. These conditions gave color, turbidity, chemical oxygen demand (COD) and conductivity removals of 99.8, 99.6, 97.1 and 35%, respectively. It was concluded that it is feasible to treat the wastewaters generated in the contaminated soil washing process through CF process, and therefore, wastewaters could be recycled to the washing process or disposed to drainage.

Extraction of contaminants from a gas

DOEpatents

Babko-Malyi, Sergei

2000-01-01

A method of treating industrial gases to remove contaminants is disclosed. Ions are generated in stream of injectable gas. These ions are propelled through the contaminated gas as it flows through a collection unit. An electric field is applied to the contaminated gas. The field causes the ions to move through the contaminated gases, producing electrical charges on the contaminants. The electrically charged contaminants are then collected at one side of the electric field. The injectable gas is selected to produce ions which will produce reactions with particular contaminants. The process is thus capable of removing particular contaminants. The process does not depend on diffusion as a transport mechanism and is therefore suitable for removing contaminants which exist in very low concentrations.

Multi-Objective Optimization of an In situ Bioremediation Technology to Treat Perchlorate-Contaminated Groundwater

EPA Science Inventory

The presentation shows how a multi-objective optimization method is integrated into a transport simulator (MT3D) for estimating parameters and cost of in-situ bioremediation technology to treat perchlorate-contaminated groundwater.

Relating monolithic and granular leaching from contaminated soil treated with different cementitious binders.

PubMed

Kogbara, Reginald B; Al-Tabbaa, Abir; Stegemann, Julia A

2013-01-01

This work employed a clayey, silty, sandy gravel contaminated with a mixture of metals (Cd, Cu, Pb, Ni and Zn) and diesel. The contaminated soil was treated with 5 and 10% dosages of different cementitious binders. The binders include Portland cement, cement-fly ash, cement-slag and lime-slag mixtures. Monolithic leaching from the treated soils was evaluated over a 64-day period alongside granular leachability of 49- and 84-day old samples. Surface wash-off was the predominant leaching mechanism for monolithic samples. In this condition, with data from different binders and curing ages combined, granular leachability as a function of monolithic leaching generally followed degrees 4 and 6 polynomial functions. The only exception was for Cu, which followed the multistage dose-response model. The relationship between both leaching tests varied with the type of metal, curing age/residence time of monolithic samples in the leachant, and binder formulation. The results provide useful design information on the relationship between leachability of metals from monolithic forms of S/S treated soils and the ultimate leachability in the eventual breakdown of the stabilized/solidified soil.

Composition and process for organic and metal contaminant fixation in soil

DOEpatents

Schwitzgebel, Klaus

1994-02-08

A method and compositions using a first ferrous iron containing solution with the iron concentration in excess of theoretical requirements to treat a contaminated site to reduce hexavalent chromium to trivalent chromium and coprecipitate trivalent chromium with other heavy metals and using a second solution of silicate containing a destabilizing salt to form a relatively impermeable gel in the contaminated site thereby fixing metals and organics to the extent that there should be no detectable ground water contamination.

Nationwide reconnaissance of contaminants of emerging concern in source and treated drinking waters of the United States

USGS Publications Warehouse

Glassmeyer, Susan T.; Furlong, Edward T.; Kolpin, Dana W.; Batt, Angela L.; Benson, Robert; Boone, J. Scott; Conerly, Octavia D.; Donohue, Maura J.; King, Dawn N.; Kostich, Mitchell S.; Mash, Heath E.; Pfaller, Stacy; Schenck, Kathleen M.; Simmons, Jane Ellen; Varughese, Eunice A.; Vesper, Stephen J.; Villegas, Eric N.; Wilson, Vickie S.

2017-01-01

When chemical or microbial contaminants are assessed for potential effect or possible regulation in ambient and drinking waters, a critical first step is determining if the contaminants occur and if they are at concentrations that may cause human or ecological health concerns. To this end, source and treated drinking water samples from 29 drinking water treatment plants (DWTPs) were analyzed as part of a two-phase study to determine whether chemical and microbial constituents, many of which are considered contaminants of emerging concern, were detectable in the waters. Of the 84 chemicals monitored in the 9 Phase I DWTPs, 27 were detected at least once in the source water, and 21 were detected at least once in treated drinking water. In Phase II, which was a broader and more comprehensive assessment, 247 chemical and microbial analytes were measured in 25 DWTPs, with 148 detected at least once in the source water, and 121 detected at least once in the treated drinking water. The frequency of detection was often related to the analyte's contaminant class, as pharmaceuticals and anthropogenic waste indicators tended to be infrequently detected and more easily removed during treatment, while per and polyfluoroalkyl substances and inorganic constituents were both more frequently detected and, overall, more resistant to treatment. The data collected as part of this project will be used to help inform evaluation of unregulated contaminants in surface water, groundwater, and drinking water.

Nationwide reconnaissance of contaminants of emerging concern in source and treated drinking waters of the United States.

PubMed

Glassmeyer, Susan T; Furlong, Edward T; Kolpin, Dana W; Batt, Angela L; Benson, Robert; Boone, J Scott; Conerly, Octavia; Donohue, Maura J; King, Dawn N; Kostich, Mitchell S; Mash, Heath E; Pfaller, Stacy L; Schenck, Kathleen M; Simmons, Jane Ellen; Varughese, Eunice A; Vesper, Stephen J; Villegas, Eric N; Wilson, Vickie S

2017-03-01

When chemical or microbial contaminants are assessed for potential effect or possible regulation in ambient and drinking waters, a critical first step is determining if the contaminants occur and if they are at concentrations that may cause human or ecological health concerns. To this end, source and treated drinking water samples from 29 drinking water treatment plants (DWTPs) were analyzed as part of a two-phase study to determine whether chemical and microbial constituents, many of which are considered contaminants of emerging concern, were detectable in the waters. Of the 84 chemicals monitored in the 9 Phase I DWTPs, 27 were detected at least once in the source water, and 21 were detected at least once in treated drinking water. In Phase II, which was a broader and more comprehensive assessment, 247 chemical and microbial analytes were measured in 25 DWTPs, with 148 detected at least once in the source water, and 121 detected at least once in the treated drinking water. The frequency of detection was often related to the analyte's contaminant class, as pharmaceuticals and anthropogenic waste indicators tended to be infrequently detected and more easily removed during treatment, while per and polyfluoroalkyl substances and inorganic constituents were both more frequently detected and, overall, more resistant to treatment. The data collected as part of this project will be used to help inform evaluation of unregulated contaminants in surface water, groundwater, and drinking water. Published by Elsevier B.V.

Why Do People Stop Treating Contaminated Drinking Water with Solar Water Disinfection (SODIS)?

ERIC Educational Resources Information Center

Tamas, Andrea; Mosler, Hans-Joachim

2011-01-01

Solar Water Disinfection (SODIS) is a simple method designed to treat microbiologically contaminated drinking water at household level. This article characterizes relapse behavior in comparison with continued SODIS use after a 7-month nonpromotion period. In addition, different subtypes among relapsers and continuers were assumed to diverge mainly…

Near Critical/Supercritical Carbon Dioxide Extraction for Treating Contaminated Bilgewater

DTIC Science & Technology

2000-02-24

SUMMARY i TABLE OF CONTENTS ii LIST OF FIGURES iii LIST OF TABLES iii 1. INTRODUCTION 1 1.1 Current Treatment Processes 1 2. SUPERCRITICAL...Treatment Processes Historically, the Navy has relied on gravimetric separation to remove oily contaminants from bilgewater. Most ships contain one...continuously changes the orientation of the separator with respect to gravity, lowering the effectiveness of a separation process that relies on subtle

FIELD EVALUATION OF THE LIGNIN-DEGRADING FUNGUS PHANEROCHAETE SORDIDA TO TREAT CREOSOTE-CONTAMINATED SOIL

EPA Science Inventory

A field study to determine the ability of selected lignin-degrading fungi to remediate soil contaminated with creosote was performed at a wood-treating facility in south central Mississippi in the autumn of 1991. The effects of solid-phase bioremediation with Phanerochaete sordid...

A hybrid approach for treating fluorided water and biogeophysical monitoring of treatment processes

NASA Astrophysics Data System (ADS)

Singh, K. P.

2016-12-01

A laboratory experiment has been conducted for investigating the possibility of development of novel techniques for treating fluoride contamination and monitoring of physico-chemical alterations caused by biogeochemical processes in the media. In the present study, high adsorption capacity and ion-exchange property of natural zeolites have been utilized in treating fluoride contamination. The preset goals are achieved by designing and constructing experimental setup consisting of three columns, first one is filled with 450 ppm fluorided water prepared by dissolving sodium fluoride in deionized water, the second is filled with zeolite and fluorided water, and the third is filled with zeolite, fluorided water, sodium lactate and the bacterial seed. The first and the second columns were poisoned with sodium azide for preventing the growth of microorganisms. The self-potential (SP) signals associated with physico-chemical alterations in natural zeolite induced by biogeochemical processes are measured by using Cu-CuSO4 gel electrodes. Liquid-phase analysis of samples from column two and three show the reduced concentrations of fluoride and aluminum and it indicates the possibility of precipitation of insoluble aluminum fluoride. This is further confirmed by the presence of fluoride and aluminum in the solid samples as detected by energy dispersive X-ray analysis. The distinct SP of the order of -50 mV and 200 mV have been associated with biostimulated fluoride remediation and geochemical fluoride remediation processes respectively. Thus, there is a possibility of non-invasive monitoring of fluoride remediation processes driven by both microbes and chemical processes. It is found that after thirty-day nitrate and sulfate is introduced in column two due chemical interaction between water and natural zeolite. Furthermore, this study demonstrates that a hybrid approach, a combination of ion exchange and adsorption properties of natural zeolite and the bioremediation is more

Considerations in Deciding to Treat Contaminated Unsaturated Soils In Situ

EPA Pesticide Factsheets

The purpose of this Issue Paper is to assist the user in deciding if in situ treatment of contaminated soil is a potentially feasible remedial alternative and to assist in the process of reviewing and screening in situ technologies.

Apparatus for extraction of contaminants from a gas

DOEpatents

Babko-Malyi, Sergei

2001-01-01

A method of treating industrial gases to remove contaminants is disclosed. Ions are generated in stream of injectable gas. These ions are propelled through the contaminated gas as it flows through a collection unit. An electric field is applied to the contaminated gas. The field causes the ions to move through the contaminated gases, producing electrical charges on the contaminants. The electrically charged contaminants are then collected at one side of the electric field. The injectable gas is selected to produce ions which will produce reactions with particular contaminants. The process is thus capable of removing particular contaminants. The process does not depend on diffusion as a transport mechanism and is therefore suitable for removing contaminants which exist in very low concentrations.

Contamination concerns in the modular containerless processing facility

NASA Technical Reports Server (NTRS)

Seshan, P. K.; Trinh, E. H.

1989-01-01

This paper describes the problems of the control and management of contamination in the Modular Containerless Processing Facility (MCPF), that is being currently developed at the JPL for the Space Station, and in the MCPF's precursor version, called the Drop Physics Module (DPM), which will be carried aboard one or more Space Shuttle missions. Attention is given to the identification of contamination sources, their mode of transport to the sample positioned within the chamber, and the protection of the sample, as well as to the mathematical simulatiom of the contaminant transport. It is emphasized that, in order to choose and implement the most appropriate contamination control strategy for each investigator, a number of simplified mathematical simulations will have to be developed, and ground-based contamination experiments will have to be carried out with identical materials.

Processing plutonium-contaminated soil on Johnston Atoll

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

Moroney, K.; Moroney, J. III; Turney, J.

1994-07-01

This article describes a cleanup project to process plutonium- and americium-contaminated soil on Johnston Atoll for volume reduction. Thermo Analytical`s (TMA`s) segmented gate system (SGS) for this remedial operation has been in successful on-site operation since 1992. Topics covered include the basis for development, a description of the Johnston Atoll; the significance of results; the benefits of the technology; applicability to other radiologically contaminated sites. 7 figs., 1 tab.

PARAMETERS OF TREATED STAINLESS STEEL SURFACES IMPORTANT FOR RESISTANCE TO BACTERIAL CONTAMINATION

EPA Science Inventory

Use of materials that are resistant to bacterial contamination could enhance food safety during processing. Common finishing treatments of stainless steel surfaces used for components of poultry processing equipment were tested for resistance to bacterial attachment. Surface char...

The importance of quality control in validating concentrations of contaminants of emerging concern in source and treated drinking water samples.

EPA Science Inventory

A national-scale survey of 247 contaminants of emerging concern (CECs), including organic and inorganic chemical compounds, and microbial contaminants, was conducted in source and treated drinking water samples from 25 treatment plants across the United States. Multiple methods w...

Characterizing Salmonella Contamination in Two Rendering Processing Plants.

PubMed

Gong, Chao; Jiang, Xiuping

2017-02-01

A microbiological investigation on Salmonella contamination was conducted in two U.S. rendering plants to investigate the potential cross-contamination of Salmonella in the rendering processing environment. Sampling locations were predetermined at the areas where Salmonella contamination may potentially occur, including raw materials receiving, crax (rendered materials before grinding process) grinding, and finished meal loading-out areas. Salmonella was either enumerated directly on xylose lysine Tergitol 4 agar plates or enriched in Rappaport-Vassiliadis and tetrathionate broths. The presumptive Salmonella isolates were confirmed using CHROMagar plating and latex agglutination testing and then characterized using pulsed-field gel electrophoresis, serotyping, and biofilm-forming determination. Among 108 samples analyzed, 79 (73%) samples were Salmonella positive after enrichment. Selected Salmonella isolates (n = 65) were assigned to 31 unique pulsed-field gel electrophoresis patterns, with 16 Salmonella serotypes, including Typhimurium and Mbandaka, identified as predominant serotypes and 10 Salmonella strains determined as strong biofilm formers. Our results indicated that the raw materials receiving area was the primary source of Salmonella and that the surfaces surrounding crax grinding and finished meal loading-out areas harbor Salmonella in biofilms that may recontaminate the finished meals. The same Salmonella serotypes found in both raw materials receiving and the finished meal loading-out areas suggested a potential of cross-contamination between different areas in the rendering processing environment.

Microbial biosafety of pilot-scale bioreactor treating MTBE and TBA-contaminated drinking water supply.

PubMed

Schmidt, Radomir; Klemme, David A; Scow, Kate; Hristova, Krassimira

2012-03-30

A pilot-scale sand-based fluidized bed bioreactor (FBBR) was utilized to treat both methyl tert-butyl ether (MTBE) and tert-butyl alcohol (TBA) from a contaminated aquifer. To evaluate the potential for re-use of the treated water, we tested for a panel of water quality indicator microorganisms and potential waterborne pathogens including total coliforms, Escherichia coli, Salmonella and Shigella spp., Campylobacter jejuni, Aeromonas hydrophila, Legionella pneumophila, Vibrio cholerae, Yersinia enterocolytica and Mycobacterium avium in both influent and treated waters from the bioreactor. Total bacteria decreased during FBBR treatment. E. coli, Salmonella and Shigella spp., C. jejuni, V. cholerae, Y. enterocolytica and M. avium were not detected in aquifer water or bioreactor treated water samples. For those pathogens detected, including total coliforms, L. pneumophila and A. hydrophila, numbers were usually lower in treated water than influent samples, suggesting removal during treatment. The detection of particular bacterial species reflected their presence or absence in the influent waters. Copyright © 2012 Elsevier B.V. All rights reserved.

Effective treatment of PAH contaminated Superfund site soil with the peroxy-acid process.

PubMed

Scott Alderman, N; N'Guessan, Adeola L; Nyman, Marianne C

2007-07-31

Peroxy-organic acids are formed by the chemical reaction between organic acids and hydrogen peroxide. The peroxy-acid process was applied to two Superfund site soils provided by the U.S. Environmental Protection Agency (EPA). Initial small-scale experiments applied ratios of 3:5:7 (v/v/v) or 3:3:9 (v/v/v) hydrogen peroxide:acetic acid:deionized (DI) water solution to 5g of Superfund site soil. The experiment using 3:5:7 (v/v/v) ratio resulted in an almost complete degradation of the 14 EPA regulated polycyclic aromatic hydrocarbons (PAHs) in Bedford LT soil during a 24-h reaction period, while the 3:3:9 (v/v/v) ratio resulted in no applicable degradation in Bedford LT lot 10 soil over the same reaction period. Specific Superfund site soil characteristics (e.g., pH, total organic carbon content and particle size distribution) were found to play an important role in the availability of the PAHs and the efficiency of the transformation during the peroxy-acid process. A scaled-up experiment followed treating 150g of Bedford LT lot 10 soil with and without mixing. The scaled-up processes applied a 3:3:9 (v/v/v) solution resulting in significant decrease in PAH contamination. These findings demonstrate the peroxy-acid process as a viable option for the treatment of PAH contaminated soils. Further work is necessary in order to elucidate the mechanisms of this process.

Method for treating a nuclear process off-gas stream

DOEpatents

Pence, Dallas T.; Chou, Chun-Chao

1984-01-01

Disclosed is a method for selectively removing and recovering the noble gas and other gaseous components typically emitted during nuclear process operations. The method is adaptable and useful for treating dissolver off-gas effluents released during reprocessing of spent nuclear fuels whereby to permit radioactive contaminant recovery prior to releasing the remaining off-gases to the atmosphere. Briefly, the method sequentially comprises treating the off-gas stream to preliminarily remove NO.sub.x, hydrogen and carbon-containing organic compounds, and semivolatile fission product metal oxide components therefrom; adsorbing iodine components on silver-exchanged mordenite; removing water vapor carried by said stream by means of a molecular sieve; selectively removing the carbon dioxide components of said off-gas stream by means of a molecular sieve; selectively removing xenon in gas phase by passing said stream through a molecular sieve comprising silver-exchanged mordenite; selectively separating krypton from oxygen by means of a molecular sieve comprising silver-exchanged mordenite; selectively separating krypton from the bulk nitrogen stream using a molecular sieve comprising silver-exchanged mordenite cooled to about -140.degree. to -160.degree. C.; concentrating the desorbed krypton upon a molecular sieve comprising silver-exchange mordenite cooled to about -140.degree. to -160.degree. C.; and further cryogenically concentrating, and the recovering for storage, the desorbed krypton.

Contamination control methods for gases used in the microlithography process

NASA Astrophysics Data System (ADS)

Rabellino, Larry; Applegarth, Chuck; Vergani, Giorgio

2002-07-01

Sensitivity to contamination continues to increase as the technology shrinks from 365 nm I-line lamp illumination to 13.4 nm Extreme Ultraviolet laser activated plasma. Gas borne impurities can be readily distributed within the system, remaining both suspended in the gas and attached to critical surfaces. Effects from a variety of contamination, some well characterized and others not, remain a continuing obstacle for stepper manufacturers and users. Impurities like oxygen, moisture and hydrocarbons in parts per billion levels can absorb light, reducing the light intensity and subsequently reducing the consistence of the process. Moisture, sulfur compounds, ammonia, acid compounds and organic compounds such as hydrocarbons can deposit on lens or mirror surfaces affecting image quality. Regular lens replacement or removal for cleaning is a costly option and in-situ cleaning processes must be carefully managed to avoid recontamination of the system. The contamination can come from outside the controlled environment (local gas supply, piping system, & leaks), or from the materials moving into the controlled environment; or contamination may be generated inside the controlled environment as a result of the process itself. The release of amines can occur as a result of the degassing of the photo-resists. For the manufacturer and user of stepper equipment, the challenge is not in predictable contamination, but the variable or unpredictable contamination in the process. One type of unpredictable contamination may be variation in the environmental conditions when producing the nitrogen gas and Clean Dry Air (CDA). Variation in the CDA, nitrogen and xenon may range from parts per billion to parts per million. The risk due to uncontrolled or unmonitored variation in gas quality can be directly related to product defects. Global location can significantly affect the gas quality, due to the ambient air quality (for nitrogen and CDA), production methods, gas handling equipment

Processes of contaminant accumulation in an Arctic beluga whale population

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

Hickie, B.E.; Muir, D.; Kingsley, M.

1995-12-31

As long-lived top predators in marine food chains, marine mammals accumulate high levels of persistent organic contaminants. While arctic marine mammal contaminant concentrations are lower than those from temperate regions, levels are sufficiently high to be a health concern to people who rely on marine mammals as food. Monitoring programs developed to address this problem and to define spatial and temporal trends often are difficult to interpret since tissue contaminant concentrations vary with species, age, sex, reproductive effort, and condition (ie blubber thickness). It can be difficult to relate contaminant concentrations in other environmental compartments to those in marine mammalsmore » since their residues reflect exposure over their entire life, often 20 to 30 years. Contaminant accumulation models for marine mammals enable us to better understand the importance of, and interaction between, factors affecting contaminant accumulation, and can provide a dynamic framework for interpreting contaminant monitoring data. The authors developed two models for the beluga whale (Delphinapterus leucas): one provides a detailed view of processes at the individual level, the other examines population-based processes. The models quantify uptake, release and disposition of organic contaminants over their entire lifespan by incorporating all aspects of life-history. These models are used together to examine impact of a variety of factors on patterns and variability of PCBs found in the West Greenland beluga population (sample size: 696, 729). Factors examined include: energetics, growth, birth rate, lactation, contaminant assimilation and clearance rates, and dietary contaminant concentrations. Results are discussed in relation to the use of marine mammals for monitoring contaminant trends.« less

Photocatalytic Degradation Effect of μ-Dielectric Barrier Discharge Plasma Treated Titanium Dioxide Nanoparticles on Environmental Contaminant.

PubMed

Seo, Hyeon Jin; Hwang, Ki-Hwan; Na, Young Hoon; Boo, Jin-Hyo

2018-09-01

This study focused on the photocatalytic degradation effect of the μ-dielectric barrier discharge (μ-DBD) plasma treated titanium dioxide (TiO2) nanoparticles on environmental contaminant such as formaldehyde. TiO2 nanoparticles were treated by a μ-DBD plasma source with nitrogen gas. We analyzed the degradation of formaldehyde with the plasma treated TiO2 nanoparticles by UV-visible spectrophotometer (UV-VIS), and demonstrated that the photocatalytic activity of the μ-DBD plasma-treated TiO2 nanoparticles showed significantly high catalytic efficiency rather than without plasma treated TiO2 nanoparticles. Field emission scanning electron microscopes (FE-SEM), X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), and water contact angle analyzer were used to measure the effects of photocatalytic degradation for the plasma treated TiO2 nanoparticles.

Salmonella contamination risk points in broiler carcasses during slaughter line processing.

PubMed

Rivera-Pérez, Walter; Barquero-Calvo, Elías; Zamora-Sanabria, Rebeca

2014-12-01

Salmonella is one of the foodborne pathogens most commonly associated with poultry products. The aim of this work was to identify and analyze key sampling points creating risk of Salmonella contamination in a chicken processing plant in Costa Rica and perform a salmonellosis risk analysis. Accordingly, the following examinations were performed: (i) qualitative testing (presence or absence of Salmonella), (ii) quantitative testing (Salmonella CFU counts), and (iii) salmonellosis risk analysis, assuming consumption of contaminated meat from the processing plant selected. Salmonella was isolated in 26% of the carcasses selected, indicating 60% positive in the flocks sampled. The highest Salmonella counts were observed after bleeding (6.1 log CFU per carcass), followed by a gradual decrease during the subsequent control steps. An increase in the percentage of contamination (10 to 40%) was observed during evisceration and spray washing (after evisceration), with Salmonella counts increasing from 3.9 to 5.1 log CFU per carcass. According to the prevalence of Salmonella -contaminated carcasses released to trade (20%), we estimated a risk of 272 cases of salmonellosis per year as a result of the consumption of contaminated chicken. Our study suggests that the processes of evisceration and spray washing represent a risk of Salmonella cross-contamination and/ or recontamination in broilers during slaughter line processing.

Preliminary Results of Cleaning Process for Lubricant Contamination

NASA Astrophysics Data System (ADS)

Eisenmann, D.; Brasche, L.; Lopez, R.

2006-03-01

Fluorescent penetrant inspection (FPI) is widely used for aviation and other components for surface-breaking crack detection. As with all inspection methods, adherence to the process parameters is critical to the successful detection of defects. Prior to FPI, components are cleaned using a variety of cleaning methods which are selected based on the alloy and the soil types which must be removed. It is also important that the cleaning process not adversely affect the FPI process. There are a variety of lubricants and surface coatings used in the aviation industry which must be removed prior to FPI. To assess the effectiveness of typical cleaning processes on removal of these contaminants, a study was initiated at an airline overhaul facility. Initial results of the cleaning study for lubricant contamination in nickel, titanium and aluminum alloys will be presented.

In-Line Detection and Measurement of Molecular Contamination in Semiconductor Process Solutions

NASA Astrophysics Data System (ADS)

Wang, Jason; West, Michael; Han, Ye; McDonald, Robert C.; Yang, Wenjing; Ormond, Bob; Saini, Harmesh

2005-09-01

This paper discusses a fully automated metrology tool for detection and quantitative measurement of contamination, including cationic, anionic, metallic, organic, and molecular species present in semiconductor process solutions. The instrument is based on an electrospray ionization time-of-flight mass spectrometer (ESI-TOF/MS) platform. The tool can be used in diagnostic or analytical modes to understand process problems in addition to enabling routine metrology functions. Metrology functions include in-line contamination measurement with near real-time trend analysis. This paper discusses representative organic and molecular contamination measurement results in production process problem solving efforts. The examples include the analysis and identification of organic compounds in SC-1 pre-gate clean solution; urea, NMP (N-Methyl-2-pyrrolidone) and phosphoric acid contamination in UPW; and plasticizer and an organic sulfur-containing compound found in isopropyl alcohol (IPA). It is expected that these unique analytical and metrology capabilities will improve the understanding of the effect of organic and molecular contamination on device performance and yield. This will permit the development of quantitative correlations between contamination levels and process degradation. It is also expected that the ability to perform routine process chemistry metrology will lead to corresponding improvements in manufacturing process control and yield, the ability to avoid excursions and will improve the overall cost effectiveness of the semiconductor manufacturing process.

Process for treating biomass

DOEpatents

Campbell, Timothy J; Teymouri, Farzaneh

2015-11-04

This invention is directed to a process for treating biomass. The biomass is treated with a biomass swelling agent within the vessel to swell or rupture at least a portion of the biomass. A portion of the swelling agent is removed from a first end of the vessel following the treatment. Then steam is introduced into a second end of the vessel different from the first end to further remove swelling agent from the vessel in such a manner that the swelling agent exits the vessel at a relatively low water content.

Process for treating biomass

DOEpatents

Campbell, Timothy J.; Teymouri, Farzaneh

2015-08-11

This invention is directed to a process for treating biomass. The biomass is treated with a biomass swelling agent within the vessel to swell or rupture at least a portion of the biomass. A portion of the swelling agent is removed from a first end of the vessel following the treatment. Then steam is introduced into a second end of the vessel different from the first end to further remove swelling agent from the vessel in such a manner that the swelling agent exits the vessel at a relatively low water content.

Process for treating biomass

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

Campbell, Timothy J.; Teymouri, Farzaneh

This invention is directed to a process for treating biomass. The biomass is treated with a biomass swelling agent within the vessel to swell or rupture at least a portion of the biomass. A portion of the swelling agent is removed from a first end of the vessel following the treatment. Then steam is introduced into a second end of the vessel different from the first end to further remove swelling agent from the vessel in such a manner that the swelling agent exits the vessel at a relatively low water content.

Reducing the potential for processing contaminant formation in cereal products.

PubMed

Curtis, Tanya Y; Postles, Jennifer; Halford, Nigel G

2014-05-01

Processing contaminants may be defined as substances that are produced in a food when it is cooked or processed, are not present or are present at much lower concentrations in the raw, unprocessed food, and are undesirable either because they have an adverse effect on product quality or because they are potentially harmful. The presence of very low levels of processing contaminants in common foods is becoming an increasingly important issue for the food industry, as developments in analytical techniques and equipment bring foods under closer and closer scrutiny. This review considers the formation of lipid oxidation products, hydrogenation of polyunsaturated fatty acids to prevent lipid oxidation and the associated risk of trans fatty acid formation. The formation of acrylamide in the Maillard reaction is described, as well as the genetic and agronomic approaches being taken to reduce the acrylamide-forming potential of cereal grain. The multiple routes for the formation of furan and associated chemicals, including hydroxymethylfurfuryl, are also described. The evolving regulatory and public perception situations for these processing contaminants and their implications for the cereal supply chain are discussed, emphasising the need for cereal breeders to engage with the contaminants issue.

Polyhexamethyl biguanide can eliminate contaminant yeasts from fuel-ethanol fermentation process.

PubMed

Elsztein, Carolina; de Menezes, João Assis Scavuzzi; de Morais, Marcos Antonio

2008-09-01

Industrial ethanol fermentation is a non-sterile process and contaminant microorganisms can lead to a decrease in industrial productivity and significant economic loss. Nowadays, some distilleries in Northeastern Brazil deal with bacterial contamination by decreasing must pH and adding bactericides. Alternatively, contamination can be challenged by adding a pure batch of Saccharomyces cerevisiae-a time-consuming and costly process. A better strategy might involve the development of a fungicide that kills contaminant yeasts while preserving S. cerevisiae cells. Here, we show that polyhexamethyl biguanide (PHMB) inhibits and kills the most important contaminant yeasts detected in the distilleries of Northeastern Brazil without affecting the cell viability and fermentation capacity of S. cerevisiae. Moreover, some physiological data suggest that PHMB acts through interaction with the yeast membrane. These results support the development of a new strategy for controlling contaminant yeast population whilst keeping industrial yields high.

Feasibility Process for Remediation of the Crude Oil Contaminated Soil

NASA Astrophysics Data System (ADS)

Keum, H.; Choi, H.; Heo, H.; Lee, S.; Kang, G.

2015-12-01

More than 600 oil wells were destroyed in Kuwait by Iraqi in 1991. During the war, over 300 oil lakes with depth of up to 2m at more than 500 different locations which has been over 49km2. Therefore, approximately 22 million m3was crude oil contaminated. As exposure of more than 20 years under atmospheric conditions of Kuwait, the crude oil has volatile hydrocarbons and covered heavy oily sludge under the crude oil lake. One of crude oil contaminated soil which located Burgan Oilfield area was collected by Kuwait Oil Company and got by H-plus Company. This contaminated soil has about 42% crude oil and could not biodegraded itself due to the extremely high toxicity. This contaminated soil was separated by 2mm sieve for removal oil sludge ball. Total petroleum hydrocarbons (TPH) was analysis by GC FID and initial TPH concentration was average 48,783 mg/kg. Ten grams of the contaminated soil replaced in two micro reactors with 20mL of bio surfactant produce microorganism. Reactor 1 was added 0.1g powder hemoglobin and other reactor was not added hemoglobin at time 0 day. Those reactors shake 120 rpm on the shaker for 7 days and CO2 produced about 150mg/L per day. After 7 days under the slurry systems, the rest days operated by hemoglobin as primary carbon source for enhanced biodegradation. The crude oil contaminated soil was degraded from 48,783mg/kg to 20,234mg/kg by slurry process and final TPH concentration degraded 11,324mg/kg for 21days. Therefore, highly contaminated soil by crude oil will be combined bio slurry process and biodegradation process with hemoglobin as bio catalytic source. Keywords: crude-oil contaminated soil, bio slurry, biodegradation, hemoglobin ACKOWLEDGEMENTS This project was supported by the Korea Ministry of Environment (MOE) GAIA Program

Scrubbing of contaminants from contaminated air streams with aerogel materials with optional photocatalytic destruction

DOEpatents

Attia, Yosry A.

2000-01-01

Disclosed is a method for separating a vaporous or gaseous contaminant from an air stream contaminated therewith. This method includes the steps of: (a) passing said contaminated air into a contact zone in which is disposed an aerogel material capable of selecting adsorbing said contaminant from air and therein contacting said contaminated air with an aerogel material; and (b) withdrawing from said zone, air depleted of said contaminant. For present purposes, "contaminant" means a material not naturally occurring in ambient air and/or a material naturally occurring in air but present at a concentration above that found in ambient air. Thus, the present invention scrubs (or treats) air for the purpose of returning it to its ambient composition. Also disclosed herein is a process for the photocatalytic destruction of contaminants from an air stream wherein the contaminated air stream is passed into a control cell or contact zone in which is disposed a photocatalytic aerogel and exposing said aerogel to ultraviolet (UV) radiation for photocatalytically destroying the adsorbed contaminant, and withdrawing from said cell an exhaust air stream depleted in said contaminant.

Microbiological contamination in peanut confectionery processing plants.

PubMed

Carminati, J de A; Amorim Neto, D P; Morishita, K N; Takano, L V; Olivier Bernardi, A; Copetti, M V; do Nascimento, M da S

2016-10-01

In order to investigate Enterobacteriaceae, coliforms, Escherichia coli and Salmonella contamination, a survey was conducted at three peanut confectionery processing companies (A, B and C) in Brazil. Samples of different peanut confectionery products (n = 59), peanut raw material (n = 30), manufacturing environment (n = 116) and workers' hand surfaces (n = 12) were analysed. Salmonella and E. coli were not detected in any final product or raw material analysed. Enterobacteriaceae was isolated from 15% of final products. Coliforms were detected in only one sample. Referring to the raw material, six samples showed contamination by Enterobacteriaceae and three samples by coliforms. For the process environment, 19% and 11% of samples presented Enterobacteriaceae and coliforms. Escherichia coli was detected in 5% of samples, and one of these samples tested positive for Salmonella; this strain was serotyping as S. Heidelberg. All food handlers surveyed in Company C showed Enterobacteriaceae and coliforms on their hands. Escherichia coli was isolated from one food worker's hand. The results showed that the manufacturing environment, including food handlers were considered the main sources for possible contamination of peanut confectionery products. This has been the first study to investigate the occurrence of Salmonella and other Enterobacteriaceae throughout peanut confectionery processing lines. The results might be used to assist risk assessment studies and to establish more effective control measures. © 2016 The Society for Applied Microbiology.

Sub-ppb Oxygen Contaminant Detection in Semi-Conductor Processing

NASA Technical Reports Server (NTRS)

Man, K. F.

1995-01-01

Gaseous contaminants such as oxygen, water vapor, nitrogen and hydrocarbons are often present in the processing environment in semiconductor device fabrication and in containerless materials processing. The contaminants arise as a result of outgassing from hot surfaces or they may be part of the impurities in commercial ultra-high purity gases. Among these gaseous contaminants, oxygen is the most reactive and, therefore, has the most adverse effects on the end product. There has been an intense effort at the Jet Propulsion Laboratory to develop different types of oxygen sorbents to reduce oxygen concentration in a microgravity processing environment to sub-ppb (parts-per-billion) levels. Higher concentrations can lead to rapid surface oxide formation, hence reducing the quality of semiconductor devices. If the concentration of oxygen in a processing chamber at 1000oC is in the ppb level, it will only take approximately 10 seconds for an oxide layer to form on the surface of a sample. The interaction of oxygen with the water surface can lead to the formation of localized defects in semi-conductor devices, hence decreasing the manufacturing yield. For example, efficient production of 64 Mb RAM chips requires contaminations below ppb levels. This paper describes a technique for measuring trace quantities of oxygen contaminants by recording the monoatomic negative ions, O-, using mass spectrometry. The O- formation from the e--O2 interaction utilizes the electron dissociative attachment method that is greatly enhanced at the resonant energy (6.8 eV). The device combines a small gridded electron ionizer with a compact mass spectrometer. The concentrations of oxygen have been measured using the method of standard additions by diluting O2 in N2. The lowest detection limit obtained was 1.2 kHz (O- count rate) at a concentration of 10-10, corresponding to 0.1 ppb.

Biogeochemical redox processes and their impact on contaminant dynamics

USGS Publications Warehouse

Borch, Thomas; Kretzschmar, Ruben; Kappler, Andreas; Van Cappellen, Philippe; Ginder-Vogel, Matthew; Campbell, Kate M.

2010-01-01

Life and element cycling on Earth is directly related to electron transfer (or redox) reactions. An understanding of biogeochemical redox processes is crucial for predicting and protecting environmental health and can provide new opportunities for engineered remediation strategies. Energy can be released and stored by means of redox reactions via the oxidation of labile organic carbon or inorganic compounds (electron donors) by microorganisms coupled to the reduction of electron acceptors including humic substances, iron-bearing minerals, transition metals, metalloids, and actinides. Environmental redox processes play key roles in the formation and dissolution of mineral phases. Redox cycling of naturally occurring trace elements and their host minerals often controls the release or sequestration of inorganic contaminants. Redox processes control the chemical speciation, bioavailability, toxicity, and mobility of many major and trace elements including Fe, Mn, C, P, N, S, Cr, Cu, Co, As, Sb, Se, Hg, Tc, and U. Redox-active humic substances and mineral surfaces can catalyze the redox transformation and degradation of organic contaminants. In this review article, we highlight recent advances in our understanding of biogeochemical redox processes and their impact on contaminant fate and transport, including future research needs.

Treating contaminated organics using the DETOX process

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

Elsberry, K.D.; Dhooge, P.M.

1993-05-01

Waste matrices containing organics, radionuclides, and metals pose difficult problems in waste treatment and disposal when the organic compounds and/or metals are considered to be hazardous. This paper describes the results of bench-scale studies of DETOX applied to the components of liquid mixed wastes, with the goal of establishing parameters for designing a prototype waste treatment unit. Apparent organic reaction rate orders and the dependence of apparent reaction rate on solution composition and the contact area were measured for vacuum pump oil scintillation fluids, and trichloroethylene. Reaction rate was superior in chloride-based solutions and was proportional to the contact areamore » above about 2% w/w loading of organic. Oxidations in a 4-liter volume, mixed bench-top reactor have given destruction efficiencies of 99.9999 + % for common organics. Reaction rates achieved in the mixed bench-top reactor were one to two orders of magnitude greater than had been achieved in unmixed reactions; a thoroughly mixed reactor should be capable of oxidizing 10 to 100 + grams of organic per liter-hour. Results are also presented on the solvation efficiency of DETOX for mercury, cerium, and neodymium, and for removal/destruction of organics sorbed on vermiculite. The next stage of development will be converting the bench-top unit to continuous processing.« less

Quantitative microbial risk assessment of microbial source tracking markers in recreational water contaminated with fresh untreated and secondary treated sewage.

PubMed

Ahmed, Warish; Hamilton, Kerry A; Lobos, Aldo; Hughes, Bridie; Staley, Christopher; Sadowsky, Michael J; Harwood, Valerie J

2018-05-14

Microbial source tracking (MST) methods have provided the means to identify sewage contamination in recreational waters, but the risk associated with elevated levels of MST targets such as sewage-associated Bacteroides HF183 and other markers is uncertain. Quantitative microbial risk assessment (QMRA) modeling allows interpretation of MST data in the context of the risk of gastrointestinal (GI) illness caused by exposure to known reference pathogens. In this study, five sewage-associated, quantitative PCR (qPCR) MST markers [Bacteroides HF183 (HF183), Methanobrevibacter smithii nifH (nifH), human adenovirus (HAdV), human polyomavirus (HPyV) and pepper mild mottle virus (PMMoV)] were evaluated to determine at what concentration these nucleic acid markers reflected a significant health risk from exposure to fresh untreated or secondary treated sewage in beach water. The QMRA models were evaluated for a target probability of illness of 36 GI illnesses/1000 swimming events (i.e., risk benchmark 0.036) for the reference pathogens norovirus (NoV) and human adenovirus 40/41 (HAdV 40/41). Sewage markers at several dilutions exceeded the risk benchmark for reference pathogens NoV and HAdV 40/41. HF183 concentrations 3.22 × 10 3 (for both NoV and HAdV 40/41) gene copies (GC)/100 mL of water contaminated with fresh untreated sewage represented risk >0.036. Similarly, HF183 concentrations 3.66 × 10 3 (for NoV and HAdV 40/41) GC/100 mL of water contaminated with secondary treated sewage represented risk >0.036. HAdV concentration as low as 4.11 × 10 1 GC/100 mL of water represented risk >0.036 when water was contaminated with secondary treated sewage. Results of this study provide a valuable context for water quality managers to evaluate human health risks associated with contamination from fresh sewage. The approach described here may also be useful in the future for evaluating health risks from contamination with aged or treated sewage or feces from other

Waste treatment process for removal of contaminants from aqueous, mixed-waste solutions using sequential chemical treatment and crossflow microfiltration, followed by dewatering

DOEpatents

Vijayan, S.; Wong, C.F.; Buckley, L.P.

1994-11-22

In processes of this invention aqueous waste solutions containing a variety of mixed waste contaminants are treated to remove the contaminants by a sequential addition of chemicals and adsorption/ion exchange powdered materials to remove the contaminants including lead, cadmium, uranium, cesium-137, strontium-85/90, trichloroethylene and benzene, and impurities including iron and calcium. Staged conditioning of the waste solution produces a polydisperse system of size enlarged complexes of the contaminants in three distinct configurations: water-soluble metal complexes, insoluble metal precipitation complexes, and contaminant-bearing particles of ion exchange and adsorbent materials. The volume of the waste is reduced by separation of the polydisperse system by cross-flow microfiltration, followed by low-temperature evaporation and/or filter pressing. The water produced as filtrate is discharged if it meets a specified target water quality, or else the filtrate is recycled until the target is achieved. 1 fig.

Waste treatment process for removal of contaminants from aqueous, mixed-waste solutions using sequential chemical treatment and crossflow microfiltration, followed by dewatering

DOEpatents

Vijayan, Sivaraman; Wong, Chi F.; Buckley, Leo P.

1994-01-01

In processes of this invention aqueous waste solutions containing a variety of mixed waste contaminants are treated to remove the contaminants by a sequential addition of chemicals and adsorption/ion exchange powdered materials to remove the contaminants including lead, cadmium, uranium, cesium-137, strontium-85/90, trichloroethylene and benzene, and impurities including iron and calcium. Staged conditioning of the waste solution produces a polydisperse system of size enlarged complexes of the contaminants in three distinct configurations: water-soluble metal complexes, insoluble metal precipitation complexes, and contaminant-bearing particles of ion exchange and adsorbent materials. The volume of the waste is reduced by separation of the polydisperse system by cross-flow microfiltration, followed by low-temperature evaporation and/or filter pressing. The water produced as filtrate is discharged if it meets a specified target water quality, or else the filtrate is recycled until the target is achieved.

Hybrid joule heating/electro-osmosis process for extracting contaminants from soil layers

DOEpatents

Carrigan, Charles R.; Nitao, John J.

2003-06-10

Joule (ohmic) heating and electro-osmosis are combined in a hybrid process for removal of both water-soluble contaminants and non-aqueous phase liquids from contaminated, low-permeability soil formations that are saturated. Central to this hybrid process is the partial desaturation of the formation or layer using electro-osmosis to remove a portion of the pore fluids by induction of a ground water flow to extraction wells. Joule heating is then performed on a partially desaturated formation. The joule heating and electro-osmosis operations can be carried out simultaneously or sequentially if the desaturation by electro-osmosis occurs initially. Joule heating of the desaturated formation results in a very effective transfer or partitioning of liquid state contaminants to the vapor phase. The heating also substantially increases the vapor phase pressure in the porous formation. As a result, the contaminant laden vapor phase is forced out into soil layers of a higher permeability where other conventional removal processes, such as steam stripping or ground water extraction can be used to capture the contaminants. This hybrid process is more energy efficient than joule heating or steam stripping for cleaning low permeability formations and can share electrodes to minimize facility costs.

Changes in metal speciation and pH in olive processing waste and sulphur-treated contaminated soil.

PubMed

de la Fuente, C; Clemente, R; Bernal, M P

2008-06-01

Degradation of organic matter from olive mill waste and changes in the heavy metal fractionation of a metal-contaminated calcareous soil were studied in a laboratory experiment, in which the olive mill waste was mixed with the soil and then incubated under aerobic conditions. The soil was calcareous (15% CaCO(3)) with high Zn and Pb concentrations (2058 and 2947 mg kg(-1), respectively). The organic amendment was applied at a rate equivalent to 20 g kg(-1) soil, and unamended soil was run as a control. To discern if changes in metal solubility were due to the acidic character of the waste, elemental sulphur was applied to soil as a non-organic acidifying material. The S(0) rates used were 3.14, 4.71 and 6.28 g kg(-1). The mineralisation of total organic-C (TOC) from the waste reached 14.8% of the original TOC concentration after 56 days of incubation. The CO(2)-C produced from S(0)-treated soils showed the carbonate destruction by the H(2)SO(4) formed through S(0) oxidation. The organic waste increased EDTA-extractable Zn and Pb concentrations and CaCl(2)-extractable Mn levels in soil after two days of incubation. The changes in metal availability with time indicated that the oxidation of phenols from the waste reduced Mn (IV) oxides, releasing Zn and Pb associated with this mineral phase. Organic waste addition did not decrease soil pH; the acidifying effect of S(0) did not change metal fractionation in the soil.

EPA and USGS scientists conduct study to determine prevalence of newly-emerging contaminants in treated and untreated drinking water

EPA Pesticide Factsheets

Scientists from the EPA and USGS are collaborating on a research study to determine the presence of contaminants of emerging concern in treated and untreated drinking water collected from drinking water treatment plants.

Exposure assessment of process-related contaminants in food by biomarker monitoring

DOE PAGES

Rietjens, Ivonne M. C. M.; Dussort, P.; Gunther, Helmut; ...

2018-01-04

Exposure assessment is a fundamental part of the risk assessment paradigm, but can often present a number of challenges and uncertainties. This is especially the case for process contaminants formed during the processing, e.g. heating of food, since they are in part highly reactive and/or volatile, thus making exposure assessment by analysing contents in food unreliable. New approaches are therefore required to accurately assess consumer exposure and thus better inform the risk assessment. Such novel approaches may include the use of biomarkers, physiologically based kinetic (PBK) modelling-facilitated reverse dosimetry, and/or duplicate diet studies. This review focuses on the state ofmore » the art with respect to the use of biomarkers of exposure for the process contaminants acrylamide, 3-MCPD esters, glycidyl esters, furan and acrolein. From the overview presented, it becomes clear that the field of assessing human exposure to process-related contaminants in food by biomarker monitoring is promising and strongly developing. The current state of the art as well as the existing data gaps and challenges for the future were defined. They include (1) using PBK modelling and duplicate diet studies to establish, preferably in humans, correlations between external exposure and biomarkers; (2) elucidation of the possible endogenous formation of the process-related contaminants and the resulting biomarker levels; (3) the influence of inter-individual variations and how to include that in the biomarker-based exposure predictions; (4) the correction for confounding factors; (5) the value of the different biomarkers in relation to exposure scenario’s and risk assessment, and (6) the possibilities of novel methodologies. Here, in spite of these challenges it can be concluded that biomarker-based exposure assessment provides a unique opportunity to more accurately assess consumer exposure to process-related contaminants in food and thus to better inform risk assessment.« less

Exposure assessment of process-related contaminants in food by biomarker monitoring

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

Rietjens, Ivonne M. C. M.; Dussort, P.; Gunther, Helmut

Exposure assessment is a fundamental part of the risk assessment paradigm, but can often present a number of challenges and uncertainties. This is especially the case for process contaminants formed during the processing, e.g. heating of food, since they are in part highly reactive and/or volatile, thus making exposure assessment by analysing contents in food unreliable. New approaches are therefore required to accurately assess consumer exposure and thus better inform the risk assessment. Such novel approaches may include the use of biomarkers, physiologically based kinetic (PBK) modelling-facilitated reverse dosimetry, and/or duplicate diet studies. This review focuses on the state ofmore » the art with respect to the use of biomarkers of exposure for the process contaminants acrylamide, 3-MCPD esters, glycidyl esters, furan and acrolein. From the overview presented, it becomes clear that the field of assessing human exposure to process-related contaminants in food by biomarker monitoring is promising and strongly developing. The current state of the art as well as the existing data gaps and challenges for the future were defined. They include (1) using PBK modelling and duplicate diet studies to establish, preferably in humans, correlations between external exposure and biomarkers; (2) elucidation of the possible endogenous formation of the process-related contaminants and the resulting biomarker levels; (3) the influence of inter-individual variations and how to include that in the biomarker-based exposure predictions; (4) the correction for confounding factors; (5) the value of the different biomarkers in relation to exposure scenario’s and risk assessment, and (6) the possibilities of novel methodologies. Here, in spite of these challenges it can be concluded that biomarker-based exposure assessment provides a unique opportunity to more accurately assess consumer exposure to process-related contaminants in food and thus to better inform risk assessment.« less

Exposure assessment of process-related contaminants in food by biomarker monitoring.

PubMed

Rietjens, Ivonne M C M; Dussort, P; Günther, Helmut; Hanlon, Paul; Honda, Hiroshi; Mally, Angela; O'Hagan, Sue; Scholz, Gabriele; Seidel, Albrecht; Swenberg, James; Teeguarden, Justin; Eisenbrand, Gerhard

2018-01-01

Exposure assessment is a fundamental part of the risk assessment paradigm, but can often present a number of challenges and uncertainties. This is especially the case for process contaminants formed during the processing, e.g. heating of food, since they are in part highly reactive and/or volatile, thus making exposure assessment by analysing contents in food unreliable. New approaches are therefore required to accurately assess consumer exposure and thus better inform the risk assessment. Such novel approaches may include the use of biomarkers, physiologically based kinetic (PBK) modelling-facilitated reverse dosimetry, and/or duplicate diet studies. This review focuses on the state of the art with respect to the use of biomarkers of exposure for the process contaminants acrylamide, 3-MCPD esters, glycidyl esters, furan and acrolein. From the overview presented, it becomes clear that the field of assessing human exposure to process-related contaminants in food by biomarker monitoring is promising and strongly developing. The current state of the art as well as the existing data gaps and challenges for the future were defined. They include (1) using PBK modelling and duplicate diet studies to establish, preferably in humans, correlations between external exposure and biomarkers; (2) elucidation of the possible endogenous formation of the process-related contaminants and the resulting biomarker levels; (3) the influence of inter-individual variations and how to include that in the biomarker-based exposure predictions; (4) the correction for confounding factors; (5) the value of the different biomarkers in relation to exposure scenario's and risk assessment, and (6) the possibilities of novel methodologies. In spite of these challenges it can be concluded that biomarker-based exposure assessment provides a unique opportunity to more accurately assess consumer exposure to process-related contaminants in food and thus to better inform risk assessment.

Laser cutting eliminates nucleic acid cross-contamination in dried-blood-spot processing.

PubMed

Murphy, Sean C; Daza, Glenda; Chang, Ming; Coombs, Robert

2012-12-01

Dried blood spots (DBS) are useful for molecular assays but are prone to false positives from cross-contamination. In our malaria DBS assay, cross-contamination was encountered despite cleaning techniques suitable for HIV-1. We therefore developed a contact-free laser cutting system that effectively eliminated cross-contamination during DBS processing.

Laser Cutting Eliminates Nucleic Acid Cross-Contamination in Dried-Blood-Spot Processing

PubMed Central

Daza, Glenda; Chang, Ming; Coombs, Robert

2012-01-01

Dried blood spots (DBS) are useful for molecular assays but are prone to false positives from cross-contamination. In our malaria DBS assay, cross-contamination was encountered despite cleaning techniques suitable for HIV-1. We therefore developed a contact-free laser cutting system that effectively eliminated cross-contamination during DBS processing. PMID:23052309

Contaminant treatment method

DOEpatents

Shapiro, Andrew Philip; Thornton, Roy Fred; Salvo, Joseph James

2003-01-01

The present invention provides a method for treating contaminated media. The method comprises introducing remediating ions consisting essentially of ferrous ions, and being peroxide-free, in the contaminated media; applying a potential difference across the contaminated media to cause the remediating ions to migrate into contact with contaminants in the contaminated media; chemically degrading contaminants in the contaminated media by contact with the remediating ions; monitoring the contaminated media for degradation products of the contaminants; and controlling the step of applying the potential difference across the contaminated media in response to the step of monitoring.

Practicing safe cell culture: applied process designs for minimizing virus contamination risk.

PubMed

Kiss, Robert D

2011-01-01

CONFERENCE PROCEEDING Proceedings of the PDA/FDA Adventitious Viruses in Biologics: Detection and Mitigation Strategies Workshop in Bethesda, MD, USA; December 1-3, 2010 Guest Editors: Arifa Khan (Bethesda, MD), Patricia Hughes (Bethesda, MD) and Michael Wiebe (San Francisco, CA) Genentech responded to a virus contamination in its biologics manufacturing facility by developing and implementing a series of barriers specifically designed to prevent recurrence of this significant and impactful event. The barriers included steps to inactivate or remove potential virus particles from the many raw materials used in cell culture processing. Additionally, analytical testing barriers provided protection of the downstream processing areas should a culture contamination occur, and robust virus clearance capability provided further assurance of virus safety should a low level contamination go undetected. This conference proceeding will review Genentech's approach, and lessons learned, in minimizing virus contamination risk in cell culture processes through multiple layers of targeted barriers designed to deliver biologics products with high success rates.

Contamination or changes of food factors during processing and modleing-safety related issue

USDA-ARS?s Scientific Manuscript database

Cross-contamination and food property changes, including chemical and physical, are common during food processing and preservation. The contamination may involve microbial and chemical aspects resulted in food-borne pathogen outbreaks and/or poisons. Chemical contaminations are most likely from th...

Recycled Fiber Properties as Affected by Contaminants and Removal Processes.

DTIC Science & Technology

Five materials were applied to either a kraft pulp furnish or to a kraft paper and were removed by conventional removal processes. Uncontaminated... kraft paper subjected to the same removal processes determined that the process, not the contaminant, was responsible for changes in sheet properties

Proposal of a sequential treatment methodology for the safe reuse of oil sludge-contaminated soil.

PubMed

Mater, L; Sperb, R M; Madureira, L A S; Rosin, A P; Correa, A X R; Radetski, C M

2006-08-25

In this study sequential steps were used to treat and immobilize oil constituents of an oil sludge-contaminated soil. Initially, the contaminated soil was oxidized by a Fenton type reaction (13 wt% for H(2)O(2); 10mM for Fe(2+)). The oxidative treatment period of 80 h was carried out under three different pH conditions: 20 h at pH 6.5, 20 h at pH 4.5, and 40 h at pH 3.0. The oxidized contaminated sample (3 kg) was stabilized and solidified for 2h with clay (1 kg) and lime (2 kg). Finally, this mixture was solidified by sand (2 kg) and Portland cement (4 kg). In order to evaluate the efficiency of different processes to treat and immobilize oil contaminants of the oil sludge-contaminated soil, leachability and solubility tests were performed and extracts were analyzed according to the current Brazilian waste regulations. Results showed that the Fenton oxidative process was partially efficient in degrading the oil contaminants in the soil, since residual concentrations were found for the PAH and BTEX compounds. Leachability tests showed that clay-lime stabilization/solidification followed by Portland cement stabilization/solidification was efficient in immobilizing the recalcitrant and hazardous constituents of the contaminated soil. These two steps stabilization/solidification processes are necessary to enhance environmental protection (minimal leachability) and to render final product economically profitable. The treated waste is safe enough to be used on environmental applications, like roadbeds blocks.

Innovative Use of Cr(VI) Plume Depictions and Pump-and-Treat Capture Analysis to Estimate Risks of Contaminant Discharge to Surface Water at Hanford Reactor Areas

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

Miller, Chuck W.; Hanson, James P.; Ivarson, Kristine A.

2015-01-14

The Hanford Site nuclear reactor operations required large quantities of high-quality cooling water, which was treated with chemicals including sodium dichromate dihydrate for corrosion control. Cooling water leakage, as well as intentional discharge of cooling water to ground during upset conditions, produced extensive groundwater recharge mounds consisting largely of contaminated cooling water and resulted in wide distribution of hexavalent chromium (Cr[VI]) contamination in the unconfined aquifer. The 2013 Cr(VI) groundwater plumes in the 100 Areas cover approximately 6 km2 (1500 acres), primarily in the 100-HR-3 and 100-KR-4 groundwater operable units (OUs). The Columbia River is a groundwater discharge boundary; wheremore » the plumes are adjacent to the Columbia River there remains a potential to discharge Cr(VI) to the river at concentrations above water quality criteria. The pump-and-treat systems along the River Corridor are operating with two main goals: 1) protection of the Columbia River, and 2) recovery of contaminant mass. An evaluation of the effectiveness of the pump-and-treat systems was needed to determine if the Columbia River was protected from contamination, and also to determine where additional system modifications may be needed. In response to this need, a technique for assessing the river protection was developed which takes into consideration seasonal migration of the plume and hydraulic performance of the operating well fields. Groundwater contaminant plume maps are generated across the Hanford Site on an annual basis. The assessment technique overlays the annual plume and the capture efficiency maps for the various pump and treat systems. The river protection analysis technique was prepared for use at the Hanford site and is described in detail in M.J. Tonkin, 2013. Interpolated capture frequency maps, based on mapping dynamic water level observed in observation wells and derived water levels in the vicinity of extraction and injection

Full scale remediation of an explosives-contaminated site at Yorktown Naval Weapons Station using the SABRE{trademark} process

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

Kaake, R.H.; Bono, J.; Yergovich, T.

Characterization of a former weapons loading and assembly facility identified soil contaminated with the explosives TNT (2,4,6-trinitrotoluene) and RDX (hexahydro-1,3,5-trinitro-1,3,5-triazine). The site contains of a variety of discrete soil types that include clay, sand, and humus. A portion of the site is also periodically submerged due to tidal action. Treatability studies were performed in conjunction with the Army Corps of Engineers Waterways Experiment Station. Studies indicated the SABRE Process could successfully treat the soil to the specified treatment goals. A full scale demonstration of the Simplot Anaerobic Biological Remediation (SABRE{trademark}) Process was carried out at the Yorktown, Virginia Naval Weaponsmore » Station. Over 650 yd{sup 3} of soil was treated to less than 2.5 mg/kg TNT in approximately 30 days. Initial concentrations were estimated to be 450 mg/kg. The soil was screened and placed into an in-ground, double-lined biocell using a soil fluidizing system.« less

On-farm and postharvest processing sources of bacterial contamination to melon rinds.

PubMed

Gagliardi, J V; Millner, P D; Lester, G; Ingram, D

2003-01-01

Multistate and international foodborne illness outbreaks, particularly involving cantaloupe and often involving rare Salmonella spp., have increased dramatically over the past 13 years. This study assessed the sources and extent of melon rind contamination in production fields and at processing and packing facilities. In the spring of 1999, cantaloupe (Cucumis melo L. [reticulatus group] cv. Cruiser) sampled from two sites in the Rio Grande River Valley showed that postharvest-processed melon rinds often had greater plate counts of bacterial contaminants than field-fresh melons. Cantaloupe in the field had 2.5 to 3.5 log CFU g(-1) rind total coliforms by aerobic plate counts, whereas washed melons had 4.0 to 5.0 log CFU g(-1). In the fall of 1999, coliforms on honeydew melons (C. melo [inodorous group] cv. Honey Brew) ranged from 2.6 to 3.7 log CFU g(-1) after processing, and total and fecal coliforms and enterococci never fell below 2.5 log CFU g(-1). A hydrocooler at another site contaminated cantaloupe rinds with up to 3.4 log CFU g(-1) total and fecal enterococci; a secondary rinse with chlorinated water incompletely removed these bacteria. Sources of coliforms and enterococci were at high levels in melon production soils, especially in furrows that were flood irrigated, in standing water at one field, and in irrigation water at both sites. At one processing facility, wash water pumped from the Rio Grande River may not have been sufficiently disinfected prior to use. Because soil, irrigation water, and process water were potential sources of bacterial contamination, monitoring and management on-farm and at processing and packing facilities should focus on water quality as an important control point for growers and packers to reduce bacterial contamination on melon rinds.

Contamination Control and Hardware Processing Solutions at Marshall Space Flight Center

NASA Technical Reports Server (NTRS)

Burns, DeWitt H.; Hampton, Tammy; Huey, LaQuieta; Mitchell, Mark; Norwood, Joey; Lowrey, Nikki

2012-01-01

The Contamination Control Team of Marshall Space Flight Center's Materials and Processes Laboratory supports many Programs/ Projects that design, manufacture, and test a wide range of hardware types that are sensitive to contamination and foreign object damage (FOD). Examples where contamination/FOD concerns arise include sensitive structural bondline failure, critical orifice blockage, seal leakage, and reactive fluid compatibility (liquid oxygen, hydrazine) as well as performance degradation of sensitive instruments or spacecraft surfaces such as optical elements and thermal control systems. During the design phase, determination of the sensitivity of a hardware system to different types or levels of contamination/FOD is essential. A contamination control and FOD control plan must then be developed and implemented through all phases of ground processing, and, sometimes, on-orbit use, recovery, and refurbishment. Implementation of proper controls prevents cost and schedule impacts due to hardware damage or rework and helps assure mission success. Current capabilities are being used to support recent and on-going activities for multiple Mission Directorates / Programs such as International Space Station (ISS), James Webb Space Telescope (JWST), Space Launch System (SLS) elements (tanks, engines, booster), etc. The team also advances Green Technology initiatives and addresses materials obsolescence issues for NASA and external customers, most notably in the area of solvent replacement (e.g. aqueous cleaners containing hexavalent chrome, ozone depleting chemicals (CFC s and HCFC's), suspect carcinogens). The team evaluates new surface cleanliness inspection and cleaning technologies (e.g. plasma cleaning), and maintains databases for processing support materials as well as outgassing and optical compatibility test results for spaceflight environments.

Ecotoxicological evaluation of diesel-contaminated soil before and after a bioremediation process.

PubMed

Molina-Barahona, L; Vega-Loyo, L; Guerrero, M; Ramírez, S; Romero, I; Vega-Jarquín, C; Albores, A

2005-02-01

Evaluation of contaminated sites is usually performed by chemical analysis of pollutants in soil. This is not enough either to evaluate the environmental risk of contaminated soil nor to evaluate the efficiency of soil cleanup techniques. Information on the bioavailability of complex mixtures of xenobiotics and degradation products cannot be totally provided by chemical analytical data, but results from bioassays can integrate the effects of pollutants in complex mixtures. In the preservation of human health and environment quality, it is important to assess the ecotoxicological effects of contaminated soils to obtain a better evaluation of the healthiness of this system. The monitoring of a diesel-contaminated soil and the evaluation of a bioremediation technique conducted on a microcosm scale were performed by a battery of ecotoxicological tests including phytotoxicity, Daphnia magna, and nematode assays. In this study we biostimulated the native microflora of soil contaminated with diesel by adding nutrients and crop residue (corn straw) as a bulking agent and as a source of microorganisms and nutrients; in addition, moisture was adjusted to enhance diesel removal. The bioremediation process efficiency was evaluated directly by an innovative, simple phytotoxicity test system and the diesel extracts by Daphnia magna and nematode assays. Contaminated soil samples were revealed to have toxic effects on seed germination, seedling growth, and Daphnia survival. After biostimulation, the diesel concentration was reduced by 50.6%, and the soil samples showed a significant reduction in phytotoxicity (9%-15%) and Daphnia assays (3-fold), confirming the effectiveness of the bioremediation process. Results from our microcosm study suggest that in addition to the evaluation of the bioremediation processes efficiency, toxicity testing is different with organisms representative of diverse phylogenic levels. The integration of analytical, toxicological and bioremediation data

Recent Developments for In Situ Treatment of Metal Contaminated Soils

EPA Pesticide Factsheets

This report assists the remedy selection process by providing information on four in situ technologies for treating soil contaminated with metals. The four approaches are electrokinetic remediation, phytoremediation, soil flushing, and...

Phytoremediation of a nitrogen-contaminated desert soil by native shrubs and microbial processes

DOE PAGES

Glenn, Edward P.; Jordan, Fiona; Waugh, W. Joseph

2016-02-24

Here, we combined phytoremediation and soil microbial nitrification and denitrification cycles to reduce nitrate and ammonium levels at a former uranium mill site near Monument Valley, Arizona. Ammonia used in uranium extraction was present throughout the soil profile. Sulfate,applied as sulfuric acid to solubilize uranium, was also present in the soil. These contaminants were leaching from a denuded area where a tailings pile had been removed and were migrating away from the site in groundwater. We planted the source area with two deep-rooted native shrubs, Atriplex cansescens and Sarcobatus vermiculatus, and irrigated transplants for 11 years at 20% the ratemore » of potential evapotranspiration to stimulate growth, then discontinued irrigation for 4 years. Over 15 years, total nitrogen levels dropped 82%, from 347 to 64 mg kg –1. Analysis of δ 15N supported our hypothesis that coupled microbial nitrification and denitrification processes were responsible for the loss of N. Soil sulfate levels changed little; however, evapotranspiration reduced sulfate leaching into the aquifer. For arid sites where traditional pump-and-treat methods are problematic, the Monument Valley data suggest that alternatives that incorporate native plants and rely on vadose zone biogeochemistry and hydrology could be a sustainable remediation for nitrogen contaminated soil.« less

Phytoremediation of a nitrogen-contaminated desert soil by native shrubs and microbial processes

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

Glenn, Edward P.; Jordan, Fiona; Waugh, W. Joseph

Here, we combined phytoremediation and soil microbial nitrification and denitrification cycles to reduce nitrate and ammonium levels at a former uranium mill site near Monument Valley, Arizona. Ammonia used in uranium extraction was present throughout the soil profile. Sulfate,applied as sulfuric acid to solubilize uranium, was also present in the soil. These contaminants were leaching from a denuded area where a tailings pile had been removed and were migrating away from the site in groundwater. We planted the source area with two deep-rooted native shrubs, Atriplex cansescens and Sarcobatus vermiculatus, and irrigated transplants for 11 years at 20% the ratemore » of potential evapotranspiration to stimulate growth, then discontinued irrigation for 4 years. Over 15 years, total nitrogen levels dropped 82%, from 347 to 64 mg kg –1. Analysis of δ 15N supported our hypothesis that coupled microbial nitrification and denitrification processes were responsible for the loss of N. Soil sulfate levels changed little; however, evapotranspiration reduced sulfate leaching into the aquifer. For arid sites where traditional pump-and-treat methods are problematic, the Monument Valley data suggest that alternatives that incorporate native plants and rely on vadose zone biogeochemistry and hydrology could be a sustainable remediation for nitrogen contaminated soil.« less

PROCESS OF DECONTAMINATING MATERIAL CONTAMINATED WITH RADIOACTIVITY

DOEpatents

Overholt, D.C.; Peterson, M.D.; Acken, M.F.

1958-09-16

A process is described for decontaminating metallic objects, such as stainless steel equipment, which consists in contacting such objects with nltric acid in a concentration of 35 to 60% to remove the major portion of the contamination; and thereafter contacting the partially decontaminated object with a second solution containing up to 20% of alkali metal hydroxide and up to 20% sodium tartrate to remove the remaining radioactive contaminats.

Comparison of contamination of femoral heads and pre-processed bone chips during hip revision arthroplasty.

PubMed

Mathijssen, N M C; Sturm, P D; Pilot, P; Bloem, R M; Buma, P; Petit, P L; Schreurs, B W

2013-12-01

With bone impaction grafting, cancellous bone chips made from allograft femoral heads are impacted in a bone defect, which introduces an additional source of infection. The potential benefit of the use of pre-processed bone chips was investigated by comparing the bacterial contamination of bone chips prepared intraoperatively with the bacterial contamination of pre-processed bone chips at different stages in the surgical procedure. To investigate baseline contamination of the bone grafts, specimens were collected during 88 procedures before actual use or preparation of the bone chips: in 44 procedures intraoperatively prepared chips were used (Group A) and in the other 44 procedures pre-processed bone chips were used (Group B). In 64 of these procedures (32 using locally prepared bone chips and 32 using pre-processed bone chips) specimens were also collected later in the procedure to investigate contamination after use and preparation of the bone chips. In total, 8 procedures had one or more positive specimen(s) (12.5 %). Contamination rates were not significantly different between bone chips prepared at the operating theatre and pre-processed bone chips. In conclusion, there was no difference in bacterial contamination between bone chips prepared from whole femoral heads in the operating room and pre-processed bone chips, and therefore, both types of bone allografts are comparable with respect to risk of infection.

Application of the base catalyzed decomposition process to treatment of PCB-contaminated insulation and other materials associated with US Navy vessels. Final report

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

Schmidt, A.J.; Zacher, A.H.; Gano, S.R.

1996-09-01

The BCD process was applied to dechlorination of two types of PCB-contaminated materials generated from Navy vessel decommissioning activities at Puget Sound Naval Shipyard: insulation of wool felt impregnated with PCB, and PCB-containing paint chips/debris from removal of paint from metal surfaces. The BCD process is a two-stage, low-temperature chemical dehalogenation process. In Stage 1, the materials are mixed with sodium bicarbonate and heated to 350 C. The volatilized halogenated contaminants (eg, PCBs, dioxins, furans), which are collected in a small volume of particulates and granular activated carbon, are decomposed by the liquid-phase reaction (Stage 2) in a stirred-tank reactor,more » using a high-boiling-point hydrocarbon oil as the reaction medium, with addition of a hydrogen donor, a base (NaOH), and a catalyst. The tests showed that treating wool felt insulation and paint chip wastes with Stage 2 on a large scale is feasible, but compared with current disposal costs for PCB-contaminated materials, using Stage 2 would not be economical at this time. For paint chips generated from shot/sand blasting, the solid-phase BCD process (Stage 1) should be considered, if paint removal activities are accelerated in the future.« less

Woodchip-sulfur based heterotrophic and autotrophic denitrification (WSHAD) process for nitrate contaminated water remediation.

PubMed

Li, Rui; Feng, Chuanping; Hu, Weiwu; Xi, Beidou; Chen, Nan; Zhao, Baowei; Liu, Ying; Hao, Chunbo; Pu, Jiaoyang

2016-02-01

Nitrate contaminated water can be effectively treated by simultaneous heterotrophic and autotrophic denitrification (HAD). In the present study, woodchips and elemental sulfur were used as co-electron donors for HAD. It was found that ammonium salts could enhance the denitrifying activity of the Thiobacillus bacteria, which utilize the ammonium that is produced by the dissimilatory nitrate reduction to ammonium (DNRA) in the woodchip-sulfur based heterotrophic and autotrophic denitrification (WSHAD) process. The denitrification performance of the WSHAD process (reaction constants range from 0.05485 h(-1) to 0.06637 h(-1)) is better than that of sulfur-based autotrophic denitrification (reaction constants range from 0.01029 h(-1) to 0.01379 h(-1)), and the optimized ratio of woodchips to sulfur is 1:1 (w/w). No sulfate accumulation is observed in the WSHAD process and the alkalinity generated in the heterotrophic denitrification can compensate for alkalinity consumption by the sulfur-based autotrophic denitrification. The symbiotic relationship between the autotrophic and the heterotrophic denitrification processes play a vital role in the mixotrophic environment. Copyright © 2015 Elsevier Ltd. All rights reserved.

Removal of petroleum hydrocarbons from contaminated groundwater by the combined technique of adsorption onto perlite followed by the O3/H2O2 process.

PubMed

Moussavi, Gholamreza; Bagheri, Amir

2012-09-01

Groundwater contaminated with petroleum hydrocarbons was treated using a combined system of adsorption onto powdered expanded perlite (PEP) followed by the O3/H2O2 process. The pretreatment investigations indicated a high capacity for PEP to remove petroleum hydrocarbons from the contaminated water. An experimental total petroleum hydrocarbon (TPH) adsorption capacity of 275 mg/g PEP was obtained at the natural pH of water. The experimental data fit best with the Freundlich isotherm model and pseudo-second-order adsorption model. The second phase of the experiment evaluated the performance of the O3/H2O2 process in the removal of residual TPH from pretreated water and compared the results with that of raw water. The O3/H202 process attained a maximum TPH removal rate for the pretreated water after 70 min, when 93% of the residual TPH in the effluent of the adsorption system was removed. Overall, the combination of adsorption onto PEP for 100 min and the subsequent treatment with the O3/H2O2 process for 70min eliminated over 99% of the TPH of highly petroleum-contaminated groundwater, with initial values of 162 mg/L. Therefore, we can conclude that the developed treatment system is an appropriate method of remediation for petroleum-contaminated waters.

Occurrence, distribution and contamination levels of heat-resistant moulds throughout the processing of pasteurized high-acid fruit products.

PubMed

Santos, Juliana Lane Paixão Dos; Samapundo, Simbarashe; Biyikli, Ayse; Van Impe, Jan; Akkermans, Simen; Höfte, Monica; Abatih, Emmanuel Nji; Sant'Ana, Anderson S; Devlieghere, Frank

2018-05-19

Heat-resistant moulds (HRMs) are well known for their ability to survive pasteurization and spoil high-acid food products, which is of great concern for processors of fruit-based products worldwide. Whilst the majority of the studies on HRMs over the last decades have addressed their inactivation, few data are currently available regarding their contamination levels in fruit and fruit-based products. Thus, this study aimed to quantify and identify heat-resistant fungal ascospores from samples collected throughout the processing of pasteurized high-acid fruit products. In addition, an assessment on the effect of processing on the contamination levels of HRMs in these products was carried out. A total of 332 samples from 111 batches were analyzed from three processing plants (=three processing lines): strawberry puree (n = 88, Belgium), concentrated orange juice (n = 90, Brazil) and apple puree (n = 154, the Netherlands). HRMs were detected in 96.4% (107/111) of the batches and 59.3% (197/332) of the analyzed samples. HRMs were present in 90.9% of the samples from the strawberry puree processing line (1-215 ascospores/100 g), 46.7% of the samples from the orange juice processing line (1-200 ascospores/100 g) and 48.7% of samples from the apple puree processing line (1-84 ascospores/100 g). Despite the high occurrence, the majority (76.8%, 255/332) of the samples were either not contaminated or presented low levels of HRMs (<10 ascospores/100 g). For both strawberry puree and concentrated orange juice, processing had no statistically significant effect on the levels of HRMs (p > 0.05). On the contrary, a significant reduction (p < 0.05) in HRMs levels was observed during the processing of apple puree. Twelve species were identified belonging to four genera - Byssochlamys, Aspergillus with Neosartorya-type ascospores, Talaromyces and Rasamsonia. N. fumigata (23.6%), N. fischeri (19.1%) and B. nivea (5.5%) were the predominant species in

Process for removal of ammonia and acid gases from contaminated waters

DOEpatents

King, C. Judson; MacKenzie, Patricia D.

1985-01-01

Contaminating basic gases, i.e., ammonia, and acid gases, e.g., carbon dioxide, are removed from process waters or waste waters in a combined extraction and stripping process. Ammonia in the form of ammonium ion is extracted by an immiscible organic phase comprising a liquid cation exchange component, especially an organic phosphoric acid derivative, and preferably di-2-ethyl hexyl phosphoric acid, dissolved in an alkyl hydrocarbon, aryl hydrocarbon, higher alcohol, oxygenated hydrocarbon, halogenated hydrocarbon, and mixtures thereof. Concurrently, the acidic gaseous contaminants are stripped from the process or waste waters by stripping with steam, air, nitrogen, or the like. The liquid cation exchange component has the ammonia stripped therefrom by heating, and the component may be recycled to extract additional amounts of ammonia.

Process for removal of ammonia and acid gases from contaminated waters

DOEpatents

King, C.J.; Mackenzie, P.D.

1982-09-03

Contaminating basic gases, i.e., ammonia and acid gases, e.g., carbon dioxide, are removed from process waters or waste waters in a combined extraction and stripping process. Ammonia in the form of ammonium ion is extracted by an immiscible organic phase comprising a liquid cation exchange component, especially an organic phosphoric acid derivative, and preferably di-2-ethyl hexyl phosphoric acid, dissolved in an alkyl hydrocarbon, aryl hydrocarbon, higher alcohol, oxygenated hydrocarbon, halogenated hydrocarbon, and mixtures thereof. Concurrently, the acidic gaseous contaminants are stripped from the process or waste waters by stripping with stream, air, nitrogen, or the like. The liquid cation exchange component has the ammonia stripped therefrom by heating, and the component may be recycled to extract additional amounts of ammonia.

Method of treating waste water

DOEpatents

Deininger, James P.; Chatfield, Linda K.

1995-01-01

A process of treating water to remove metal ion contaminants contained therein, said metal ion contaminants selected from the group consisting of metals in Groups 8, 1b, 2b, 4a, 5a, or 6a of the periodic table, lanthanide metals, and actinide metals including transuranic element metals, by adjusting the pH of a metal ion contaminant-containing water source to within the range of about 6.5 to about 14.0, admixing the water source with a mixture of an alkali or alkaline earth ferrate and a water soluble salt, e.g., a zirconium salt, in an amount sufficient to form a precipitate within the water source, the amount the mixture of ferrate and water soluble salt effective to reduce the metal ion contaminant concentration in the water source, permitting the precipitate in the admixture to separate and thereby yield a supernatant liquid having a reduced metal ion contaminant concentration, and separating the supernatant liquid having the reduced metal ion contaminant concentration from the admixture is provided. A composition of matter including an alkali or alkaline earth ferrate and a water soluble salt, e.g., a zirconium salt, is also provided.

Ultraviolet Laser Damage Dependence on Contamination Concentration in Fused Silica Optics during Reactive Ion Etching Process

PubMed Central

Sun, Laixi; Shao, Ting; Shi, Zhaohua; Huang, Jin; Ye, Xin; Jiang, Xiaodong; Wu, Weidong; Yang, Liming; Zheng, Wanguo

2018-01-01

The reactive ion etching (RIE) process of fused silica is often accompanied by surface contamination, which seriously degrades the ultraviolet laser damage performance of the optics. In this study, we find that the contamination behavior on the fused silica surface is very sensitive to the RIE process which can be significantly optimized by changing the plasma generating conditions such as discharge mode, etchant gas and electrode material. Additionally, an optimized RIE process is proposed to thoroughly remove polishing-introduced contamination and efficiently prevent the introduction of other contamination during the etching process. The research demonstrates the feasibility of improving the damage performance of fused silica optics by using the RIE technique. PMID:29642571

Chemical coagulation-based processes for trace organic contaminant removal: current state and future potential.

PubMed

Alexander, Jonathan T; Hai, Faisal I; Al-Aboud, Turki M

2012-11-30

Trace organic contaminants have become an increasing cause of concern for governments and water authorities as they attempt to respond to the potential challenges posed by climate change by implementing sustainable water cycle management practices. The augmentation of potable water supplies through indirect potable water reuse is one such method currently being employed. Given the uncertainty surrounding the potential human health impacts of prolonged ingestion of trace organic contaminants, it is vital that effective and sustainable treatment methods are utilized. The purpose of this article is to provide a comprehensive literature review of the performance of the chemical coagulation process in removing trace organic contaminants from water. This study evaluated the removal data collated from recent research relating to various trace organic contaminants during the coagulation process. It was observed that there is limited research data relating to the removal of trace organic contaminants using coagulation. The findings of this study suggest that there is a gap in the current research investigating the potential of new types of coagulants and exploring coagulation-based hybrid processes to remove trace organic contaminants from water. The data analysed in this study regarding removal efficiency suggests that, even for the significantly hydrophobic compounds, hydrophobicity is not the sole factor governing removal of trace organic contaminants by coagulation. This has important implications in that the usual practice of screening coagulants based on turbidity (suspended solid) removal proves inadequate in the case of trace organic contaminant removal. Copyright © 2012 Elsevier Ltd. All rights reserved.

Depth-of-processing effects on priming in stem completion: tests of the voluntary-contamination, conceptual-processing, and lexical-processing hypotheses.

PubMed

Richardson-Klavehn, A; Gardiner, J M

1998-05-01

Depth-of-processing effects on incidental perceptual memory tests could reflect (a) contamination by voluntary retrieval, (b) sensitivity of involuntary retrieval to prior conceptual processing, or (c) a deficit in lexical processing during graphemic study tasks that affects involuntary retrieval. The authors devised an extension of incidental test methodology--making conjunctive predictions about response times as well as response proportions--to discriminate among these alternatives. They used graphemic, phonemic, and semantic study tasks, and a word-stem completion test with incidental, intentional, and inclusion instructions. Semantic study processing was superior to phonemic study processing in the intentional and inclusion tests, but semantic and phonemic study processing produced equal priming in the incidental test, showing that priming was uncontaminated by voluntary retrieval--a conclusion reinforced by the response-time data--and that priming was insensitive to prior conceptual processing. The incidental test nevertheless showed a priming deficit following graphemic study processing, supporting the lexical-processing hypothesis. Adding a lexical decision to the 3 study tasks eliminated the priming deficit following graphemic study processing, but did not influence priming following phonemic and semantic processing. The results provide the first clear evidence that depth-of-processing effects on perceptual priming can reflect lexical processes, rather than voluntary contamination or conceptual processes.

Linking metatranscriptomic to bioremediation processes of oil contaminated marine sediments

NASA Astrophysics Data System (ADS)

Cuny, P.; Atkinson, A.; Léa, S.; Guasco, S.; Jezequel, R.; Armougom, F.; Michotey, V.; Bonin, P.; Militon, C.

2016-02-01

Oil-derived hydrocarbons are one major source of pollution of marine ecosystems. In coastal marine areas they tend to accumulate in the sediment where they can impact the benthic communities. Oil hydrocarbons biodegradation by microorganisms is known to be one of the prevalent processes acting in the removal of these contaminants from sediments. The redox oscillation regimes generated by bioturbation, and the efficiency of metabolic coupling between functional groups associated to these specific redox regimes, are probably determinant factors controlling hydrocarbon biodegradation. Metatranscriptomic analysis appears like a promising approach to shed new light on the metabolic processes involved in the response of microbial communities to oil contamination in such oxic/anoxic oscillating environments. In the framework of the DECAPAGE project (ANR CESA-2011-006 01), funded by the French National Agency for Research, the metatranscriptomes (RNA-seq) of oil contaminated or not (Ural blend crude oil, 5 000 ppm) and bioturbated or not (addition of the common burrowing organism Hediste diversicolor, 1000 ind/m2) mudflat sediments, incubated in microcosms during 4 months at 19±1°C, were compared. The analysis of active microbial communities by SSU rRNA barcoding shows that the main observable changes are due to the presence of H. diversicolor. On the contrary, oil addition is the main factor explaining the observed changes in the genes expression patterns with 1949 genes specifically up or down-regulated (which is the case of only 245 genes when only H. diversicolor worms are added). In particular, the oil contamination leads to a marked overexpression (i) of benzyl- and alkylsuccinate synthase genes (ass and bss) that are involved in the anaerobic metabolism of aromatics (toluene) and alkanes, respectively and, (ii) of genes coding for nucleotide excision repair exonucleases indicating that DNA repair processes are also activated.

Unit Process Wetlands for Removal of Trace Organic Contaminants and Pathogens from Municipal Wastewater Effluents

PubMed Central

Jasper, Justin T.; Nguyen, Mi T.; Jones, Zackary L.; Ismail, Niveen S.; Sedlak, David L.; Sharp, Jonathan O.; Luthy, Richard G.; Horne, Alex J.; Nelson, Kara L.

2013-01-01

Abstract Treatment wetlands have become an attractive option for the removal of nutrients from municipal wastewater effluents due to their low energy requirements and operational costs, as well as the ancillary benefits they provide, including creating aesthetically appealing spaces and wildlife habitats. Treatment wetlands also hold promise as a means of removing other wastewater-derived contaminants, such as trace organic contaminants and pathogens. However, concerns about variations in treatment efficacy of these pollutants, coupled with an incomplete mechanistic understanding of their removal in wetlands, hinder the widespread adoption of constructed wetlands for these two classes of contaminants. A better understanding is needed so that wetlands as a unit process can be designed for their removal, with individual wetland cells optimized for the removal of specific contaminants, and connected in series or integrated with other engineered or natural treatment processes. In this article, removal mechanisms of trace organic contaminants and pathogens are reviewed, including sorption and sedimentation, biotransformation and predation, photolysis and photoinactivation, and remaining knowledge gaps are identified. In addition, suggestions are provided for how these treatment mechanisms can be enhanced in commonly employed unit process wetland cells or how they might be harnessed in novel unit process cells. It is hoped that application of the unit process concept to a wider range of contaminants will lead to more widespread application of wetland treatment trains as components of urban water infrastructure in the United States and around the globe. PMID:23983451

Unit Process Wetlands for Removal of Trace Organic Contaminants and Pathogens from Municipal Wastewater Effluents.

PubMed

Jasper, Justin T; Nguyen, Mi T; Jones, Zackary L; Ismail, Niveen S; Sedlak, David L; Sharp, Jonathan O; Luthy, Richard G; Horne, Alex J; Nelson, Kara L

2013-08-01

Treatment wetlands have become an attractive option for the removal of nutrients from municipal wastewater effluents due to their low energy requirements and operational costs, as well as the ancillary benefits they provide, including creating aesthetically appealing spaces and wildlife habitats. Treatment wetlands also hold promise as a means of removing other wastewater-derived contaminants, such as trace organic contaminants and pathogens. However, concerns about variations in treatment efficacy of these pollutants, coupled with an incomplete mechanistic understanding of their removal in wetlands, hinder the widespread adoption of constructed wetlands for these two classes of contaminants. A better understanding is needed so that wetlands as a unit process can be designed for their removal, with individual wetland cells optimized for the removal of specific contaminants, and connected in series or integrated with other engineered or natural treatment processes. In this article, removal mechanisms of trace organic contaminants and pathogens are reviewed, including sorption and sedimentation, biotransformation and predation, photolysis and photoinactivation, and remaining knowledge gaps are identified. In addition, suggestions are provided for how these treatment mechanisms can be enhanced in commonly employed unit process wetland cells or how they might be harnessed in novel unit process cells. It is hoped that application of the unit process concept to a wider range of contaminants will lead to more widespread application of wetland treatment trains as components of urban water infrastructure in the United States and around the globe.

Bioremediation techniques applied to aqueous media contaminated with mercury.

PubMed

Velásquez-Riaño, Möritz; Benavides-Otaya, Holman D

2016-12-01

In recent years, the environmental and human health impacts of mercury contamination have driven the search for alternative, eco-efficient techniques different from the traditional physicochemical methods for treating this metal. One of these alternative processes is bioremediation. A comprehensive analysis of the different variables that can affect this process is presented. It focuses on determining the effectiveness of different techniques of bioremediation, with a specific consideration of three variables: the removal percentage, time needed for bioremediation and initial concentration of mercury to be treated in an aqueous medium.

High pressure processing as an intervention for raw virus-contaminated shellfish

USDA-ARS?s Scientific Manuscript database

Over the past 7 years, the USDA ARS Seafood Safety Laboratory has evaluated the potential use of high pressure processing (HPP) as a processing strategy for virus-contaminated shellfish. HPP can inactivate hepatitis A virus, (HAV), the human norovirus surrogates feline calicivirus and murine norovi...

Statistical process control for residential treated wood

Treesearch

Patricia K. Lebow; Timothy M. Young; Stan Lebow

2017-01-01

This paper is the first stage of a study that attempts to improve the process of manufacturing treated lumber through the use of statistical process control (SPC). Analysis of industrial and auditing agency data sets revealed there are differences between the industry and agency probability density functions (pdf) for normalized retention data. Resampling of batches of...

Do Contaminants Originating from State-of-the-Art Treated Wastewater Impact the Ecological Quality of Surface Waters?

PubMed Central

Stalter, Daniel; Magdeburg, Axel; Quednow, Kristin; Botzat, Alexandra; Oehlmann, Jörg

2013-01-01

Since the 1980s, advances in wastewater treatment technology have led to considerably improved surface water quality in the urban areas of many high income countries. However, trace concentrations of organic wastewater-associated contaminants may still pose a key environmental hazard impairing the ecological quality of surface waters. To identify key impact factors, we analyzed the effects of a wide range of anthropogenic and environmental variables on the aquatic macroinvertebrate community. We assessed ecological water quality at 26 sampling sites in four urban German lowland river systems with a 0–100% load of state-of-the-art biological activated sludge treated wastewater. The chemical analysis suite comprised 12 organic contaminants (five phosphor organic flame retardants, two musk fragrances, bisphenol A, nonylphenol, octylphenol, diethyltoluamide, terbutryn), 16 polycyclic aromatic hydrocarbons, and 12 heavy metals. Non-metric multidimensional scaling identified organic contaminants that are mainly wastewater-associated (i.e., phosphor organic flame retardants, musk fragrances, and diethyltoluamide) as a major impact variable on macroinvertebrate species composition. The structural degradation of streams was also identified as a significant factor. Multiple linear regression models revealed a significant impact of organic contaminants on invertebrate populations, in particular on Ephemeroptera, Plecoptera, and Trichoptera species. Spearman rank correlation analyses confirmed wastewater-associated organic contaminants as the most significant variable negatively impacting the biodiversity of sensitive macroinvertebrate species. In addition to increased aquatic pollution with organic contaminants, a greater wastewater fraction was accompanied by a slight decrease in oxygen concentration and an increase in salinity. This study highlights the importance of reducing the wastewater-associated impact on surface waters. For aquatic ecosystems in urban areas this

Do contaminants originating from state-of-the-art treated wastewater impact the ecological quality of surface waters?

PubMed

Stalter, Daniel; Magdeburg, Axel; Quednow, Kristin; Botzat, Alexandra; Oehlmann, Jörg

2013-01-01

Since the 1980s, advances in wastewater treatment technology have led to considerably improved surface water quality in the urban areas of many high income countries. However, trace concentrations of organic wastewater-associated contaminants may still pose a key environmental hazard impairing the ecological quality of surface waters. To identify key impact factors, we analyzed the effects of a wide range of anthropogenic and environmental variables on the aquatic macroinvertebrate community. We assessed ecological water quality at 26 sampling sites in four urban German lowland river systems with a 0-100% load of state-of-the-art biological activated sludge treated wastewater. The chemical analysis suite comprised 12 organic contaminants (five phosphor organic flame retardants, two musk fragrances, bisphenol A, nonylphenol, octylphenol, diethyltoluamide, terbutryn), 16 polycyclic aromatic hydrocarbons, and 12 heavy metals. Non-metric multidimensional scaling identified organic contaminants that are mainly wastewater-associated (i.e., phosphor organic flame retardants, musk fragrances, and diethyltoluamide) as a major impact variable on macroinvertebrate species composition. The structural degradation of streams was also identified as a significant factor. Multiple linear regression models revealed a significant impact of organic contaminants on invertebrate populations, in particular on Ephemeroptera, Plecoptera, and Trichoptera species. Spearman rank correlation analyses confirmed wastewater-associated organic contaminants as the most significant variable negatively impacting the biodiversity of sensitive macroinvertebrate species. In addition to increased aquatic pollution with organic contaminants, a greater wastewater fraction was accompanied by a slight decrease in oxygen concentration and an increase in salinity. This study highlights the importance of reducing the wastewater-associated impact on surface waters. For aquatic ecosystems in urban areas this

Use of sugarcane filter cake and nitrogen, phosphorus and potassium fertilization in the process of bioremediation of soil contaminated with diesel.

PubMed

Tellechea, Fernando Reynel Fundora; Martins, Marco Antônio; da Silva, Alexsandro Araujo; da Gama-Rodrigues, Emanuela Forestieri; Martins, Meire Lelis Leal

2016-09-01

This study evaluated the use of sugarcane filter cake and nitrogen, phosphorus and potassium (NPK) fertilization in the bioremediation of a soil contaminated with diesel fuel using a completely randomized design. Five treatments (uncontaminated soil, T1; soil contaminated with diesel, T2; soil contaminated with diesel and treated with 15 % (wt) filter cake, T3; soil contaminated with diesel and treated with NPK fertilizer, T4; and soil contaminated with diesel and treated with 15 % (wt) filter cake and NPK fertilizer, T5) and four evaluation periods (1, 60, 120, and 180 days after the beginning of the experiment) were used according to a 4 × 5 factorial design to analyze CO2 release. The variables total organic carbon (TOC) and total petroleum hydrocarbons (TPH) remaining in the soil were analyzed using a 5 × 2 factorial design, with the same treatments described above and two evaluation periods (1 and 180 days after the beginning of the experiment). In T3 and T5, CO2 release was significantly higher, compared with the other treatments. Significant TPH removal was observed on day 180, when percent removal values were 61.9, 70.1, 68.2, and 75.9 in treatments T2, T3, T4, and T5, respectively, compared with the initial value (T1).

Evaluation of processing factors for selected organic contaminants during virgin olive oil production: Distribution of BTEXS during olives processing.

PubMed

López-Blanco, Rafael; Gilbert-López, Bienvenida; Rojas-Jiménez, Rubén; Robles-Molina, José; Ramos-Martos, Natividad; García-Reyes, Juan F; Molina-Díaz, Antonio

2016-05-15

The presence of BTEXS (benzene, toluene, ethylbenzene, xylenes and styrene) in virgin olive oils can be attributed to environmental contamination, but also to biological processes during oil lipogenesis (styrene). In this work, the processing factor of BTEXS from olives to olive oil during its production was evaluated at lab-scale with an Abencor system. Benzene showed the lowest processing factor (15%), whereas toluene and xylenes showed an intermediate behavior (with 40-60% efficiency), and ethylbenzene and styrene were completely transferred (100%). In addition, an attempt to examine the contribution of potential sources to olives contamination with BTEXS was carried out for the first time. Two types of olives samples were classified according to their proximity to the contamination source (road). Although higher levels of BTEXS were found in samples close to roads, the concentrations were relatively low and do not constitute a major contribution to BTEXS usually detected in olive oil. Copyright © 2015 Elsevier Ltd. All rights reserved.

Nationwide reconnaissance of contaminants of emerging concern in source and treated drinking waters of the United States: Pharmaceuticals.

PubMed

Furlong, Edward T; Batt, Angela L; Glassmeyer, Susan T; Noriega, Mary C; Kolpin, Dana W; Mash, Heath; Schenck, Kathleen M

2017-02-01

sample and a median of 2 pharmaceuticals detected for all 25 samples. Source-water type influences the presence of pharmaceuticals in source and treated water. Treatment processes appear effective in reducing concentrations of most pharmaceuticals. Pharmaceuticals more consistently persisting through treatment include carbamazepine, bupropion, cotinine, metoprolol, and lithium. Pharmaceutical concentrations and compositions from this study provide an important base data set for further sublethal, long-term exposure assessments, and for understanding potential effects of these and other contaminants of emerging concern upon human and ecosystem health. Copyright © 2016. Published by Elsevier B.V.

Contamination and changes of food factors during processing with modeling applications-safety related issues

USDA-ARS?s Scientific Manuscript database

Chemical and microbiological contamination of food during processing and preservation can result in foodborne illness outbreaks and food poisoning. Chemical contaminations can occur through exposure of foods to illegal additives, pesticides and fertilizer residues, toxic compounds formed by microbes...

Process Upsets Involving Trace Contaminant Control Systems

NASA Technical Reports Server (NTRS)

Graf, John C.; Perry, Jay; Wright, John; Bahr, Jim

2000-01-01

Paradoxically, trace contaminant control systems that suffer unexpected upsets and malfunctions can release hazardous gaseous contaminants into a spacecraft cabin atmosphere causing potentially serious toxicological problems. Trace contaminant control systems designed for spaceflight typically employ a combination of adsorption beds and catalytic oxidation reactors to remove organic and inorganic trace contaminants from the cabin atmosphere. Interestingly, the same design features and attributes which make these systems so effective for purifying a spacecraft's atmosphere can also make them susceptible to system upsets. Cabin conditions can be contributing causes of phenomena such as adsorbent "rollover" and catalyst poisoning can alter a systems performance and in some in stances release contamination into the cabin. Evidence of these phenomena has been observed both in flight and during ground-based tests. The following discussion describes specific instances of system upsets found in trace contaminant control systems, groups these specific upsets into general hazard classifications, and recommends ways to minimize these hazards.

A Mathematical Model for Pathogen Cross-Contamination Dynamics during the Postharvest Processing of Leafy Greens.

PubMed

Mokhtari, Amir; Oryang, David; Chen, Yuhuan; Pouillot, Regis; Van Doren, Jane

2018-01-08

We developed a probabilistic mathematical model for the postharvest processing of leafy greens focusing on Escherichia coli O157:H7 contamination of fresh-cut romaine lettuce as the case study. Our model can (i) support the investigation of cross-contamination scenarios, and (ii) evaluate and compare different risk mitigation options. We used an agent-based modeling framework to predict the pathogen prevalence and levels in bags of fresh-cut lettuce and quantify spread of E. coli O157:H7 from contaminated lettuce to surface areas of processing equipment. Using an unbalanced factorial design, we were able to propagate combinations of random values assigned to model inputs through different processing steps and ranked statistically significant inputs with respect to their impacts on selected model outputs. Results indicated that whether contamination originated on incoming lettuce heads or on the surface areas of processing equipment, pathogen prevalence among bags of fresh-cut lettuce and batches was most significantly impacted by the level of free chlorine in the flume tank and frequency of replacing the wash water inside the tank. Pathogen levels in bags of fresh-cut lettuce were most significantly influenced by the initial levels of contamination on incoming lettuce heads or surface areas of processing equipment. The influence of surface contamination on pathogen prevalence or levels in fresh-cut bags depended on the location of that surface relative to the flume tank. This study demonstrates that developing a flexible yet mathematically rigorous modeling tool, a "virtual laboratory," can provide valuable insights into the effectiveness of individual and combined risk mitigation options. © 2018 The Authors Risk Analysis published by Wiley Periodicals, Inc. on behalf of Society for Risk Analysis.

OMNIgene.SPUTUM suppresses contaminants while maintaining Mycobacterium tuberculosis viability and obviates cold-chain transport.

PubMed

Azam, Khalide; Cadir, Nureisha; Madeira, Carla; Gillespie, Stephen H; Sabiiti, Wilber

2018-01-01

Tuberculosis (TB) diagnostics are centralised, requiring long-distance transportation of specimens in most resource-limited settings. We evaluated the ability of OMNIgene.SPUTUM (OM-S) to obviate cold-chain transport of TB specimens. A two-arm (same-day and after 5 days sample processing) study was conducted to assess contamination rates and Mycobacterium tuberculosis viability in OM-S-treated samples against the standard decontamination procedure (SDP) in Mozambique, using Lowenstein Jensen (LJ) and mycobacterial growth indicator tube (MGIT) culture and molecular bacterial load assay. 270 specimens were processed using OM-S and SDP in same-day and 5-day arms. Contamination was lower in OM-S-treated than SDP-treated cultures: 12% versus 15% and 2% versus 27% in the same-day and 5-day arms, respectively. M. tuberculosis recovery in OM-S-treated LJ cultures was 10% and 56% higher in the same-day and 5-day arms, respectively, than SDP-treated cultures, but lower in MGIT (52% and 28% lower in the same-day and 5-day arms, respectively). M. tuberculosis viable count was 1log estimated CFU·mL -1 lower in 5-day OM-S-treated sputa. OM-S was more effective at liquefying sputum with a shorter sample processing time: 22 min for culture. OM-S is simple to use and has demonstrated a high potency to suppress contaminants, maintenance of viability at ambient temperatures and higher M. tuberculosis recovery, particularly in the solid LJ cultures. Optimisation of OM-S to achieve higher MGIT culture positivity and shorter time to result will increase its application and utility in the clinical management of TB.

OMNIgene.SPUTUM suppresses contaminants while maintaining Mycobacterium tuberculosis viability and obviates cold-chain transport

PubMed Central

Azam, Khalide; Cadir, Nureisha; Madeira, Carla; Gillespie, Stephen H.; Sabiiti, Wilber

2018-01-01

Tuberculosis (TB) diagnostics are centralised, requiring long-distance transportation of specimens in most resource-limited settings. We evaluated the ability of OMNIgene.SPUTUM (OM-S) to obviate cold-chain transport of TB specimens. A two-arm (same-day and after 5 days sample processing) study was conducted to assess contamination rates and Mycobacterium tuberculosis viability in OM-S-treated samples against the standard decontamination procedure (SDP) in Mozambique, using Lowenstein Jensen (LJ) and mycobacterial growth indicator tube (MGIT) culture and molecular bacterial load assay. 270 specimens were processed using OM-S and SDP in same-day and 5-day arms. Contamination was lower in OM-S-treated than SDP-treated cultures: 12% versus 15% and 2% versus 27% in the same-day and 5-day arms, respectively. M. tuberculosis recovery in OM-S-treated LJ cultures was 10% and 56% higher in the same-day and 5-day arms, respectively, than SDP-treated cultures, but lower in MGIT (52% and 28% lower in the same-day and 5-day arms, respectively). M. tuberculosis viable count was 1log estimated CFU·mL−1 lower in 5-day OM-S-treated sputa. OM-S was more effective at liquefying sputum with a shorter sample processing time: 22 min for culture. OM-S is simple to use and has demonstrated a high potency to suppress contaminants, maintenance of viability at ambient temperatures and higher M. tuberculosis recovery, particularly in the solid LJ cultures. Optimisation of OM-S to achieve higher MGIT culture positivity and shorter time to result will increase its application and utility in the clinical management of TB. PMID:29479537

Bacterial contamination of ex vivo processed PBPC products under clean room conditions.

PubMed

Ritter, Markus; Schwedler, Joachim; Beyer, Jörg; Movassaghi, Kamran; Mutters, Reinier; Neubauer, Andreas; Schwella, Nimrod

2003-11-01

Patients undergoing high-dose radio- and/or chemotherapy and autologous or allogeneic PBPC transplantation are at high risk for infections owing to profound immunosuppression. In this study, the rate of microbial contamination of ex vivo processed PBPC products was analyzed, comparing preparation under clean room conditions to standard laboratory conditions. After implementation of good manufacturing practice conditions in the two participating institutions, the microbial contamination rate of 366 PBPC harvests from 198 patients was determined under certified clean room conditions (Group A) from 2000 until 2002. To investigate influence of improved environmental conditions along with other parameters, this set of samples was compared with a historical control set of 1413 PBPC products, which have been processed ex vivo under a clean bench in a regular laboratory room and were harvested from 626 patients (Group B) from 1989 until 2000. In Group B microbial contamination was found in 74 PBPC products (5.2%) from 57 patients. In Group A microbial growth was detected in 3 leukapheresis products (0.8%) from 3 patients. After exclusion of PBPC products, which were probably contaminated before manipulation, statistical analysis showed a significant difference (chi2= 10.339; p < 0.001). These data suggest an impact of clean room conditions on the bacterial contamination rate of PBPC products. To identify confounding variables, variables like technique of leukapheresis, culture methodology, and microbial colonization of central venous catheters were taken into account. Further variables might be identified in following studies.

Impact of Transport Crate Reuse and of Catching and Processing on Campylobacter and Salmonella Contamination of Broiler Chickens

PubMed Central

Slader, J.; Domingue, G.; Jørgensen, F.; McAlpine, K.; Owen, R. J.; Bolton, F. J.; Humphrey, T. J.

2002-01-01

The influence of transport, catching, and processing on contamination of broiler chickens with Salmonella and Campylobacter was investigated. Transport crates were reused with high frequency and were often still contaminated with Salmonella and Campylobacter when they arrived at the farm despite the fact that they were washed at the factory, and thus they were a potential route of infection. These organisms contaminated the feathers of previously Campylobacter- and Salmonella-negative birds going to the processing plant and were isolated from processed carcasses, albeit at a low frequency. The Campylobacter types which were the predominant organisms on the live birds when they arrived at the processing plant were not necessarily the types that were most frequently isolated from processed carcasses. This finding may reflect cross-contamination that occurred during processing or differences in the tolerance of the strains to the hostile environments that the bacteria experienced. The process of catching and putting the birds in crates significantly increased the chance of contamination with Campylobacter (P < 0.001). PMID:11823211

Links between contaminant hotspots in low flow estuarine systems and altered sediment biogeochemical processes

NASA Astrophysics Data System (ADS)

Sutherland, Michael D.; Dafforn, Katherine A.; Scanes, Peter; Potts, Jaimie; Simpson, Stuart L.; Sim, Vivian X. Y.; Johnston, Emma L.

2017-11-01

The urbanisation of coastal zones is a major threat to the health of global estuaries and has been linked to increased contamination (e.g. metals) and excess organic matter. Urban stormwater networks collect and funnel contaminants into waterways at point sources (e.g. stormdrains). Under dry, low flow conditions, these stormwater contaminants can accumulate in sediments over time and result in modifications to benthic sediment biogeochemical processes. To quantify these processes, this field study measured differences in benthic metabolism (CR, GPP, NEM) and sediment-water nutrient fluxes (NH3, NOx, PO4) associated with stormdrains (0 m, 200 m and 1000 m away) and increased water-retention (embayments vs channels). Significant changes to benthic metabolism were detected with distance from stormdrains, and with differences in water-retention rates, above natural spatial and temporal variation. Oxygen consumption was ∼50% higher at stormdrains (0 m) compared to 1000 m away and >70% higher at stormdrains (0 m) located in embayments compared to channels. Oxygen production also appeared to decrease with distance from stormdrains in embayments, but patterns were variable. These changes to benthic metabolism were of a magnitude expected to influence benthic nutrient cycling, but NH3, NOx and PO4 fluxes were generally low, and highly spatially and temporally variable. Overall, metal (Cu) contamination explained most of the variation in sediment biogeochemical processes between embayments and channels, while sediment grain size explained differences in fluxes with distance from stormdrains. Importantly, although there was evidence of increased productivity associated with stormdrains, we also detected evidence of early hypoxia suggesting that systems with legacy stormwater contaminants exist on a tipping point. Future work should investigate changes to sediment processes after a major rainfall event, when large and sudden inputs of potentially toxic contaminants occur

Experimental Assessment of Recycled Diesel Spill-Contaminated Domestic Wastewater Treated by Reed Beds for Irrigation of Sweet Peppers

PubMed Central

Almuktar, Suhad A.A.A.N.; Scholz, Miklas

2016-01-01

The aim of this experimental study is to assess if urban wastewater treated by ten different greenhouse-based sustainable wetland systems can be recycled to irrigate Capsicum annuum L. (Sweet Pepper; California Wonder) commercially grown either in compost or sand within a laboratory environment. The design variables were aggregate diameter, contact time, resting time and chemical oxygen demand. The key objectives were to assess: (i) the suitability of different treated (recycled) wastewaters for irrigation; (ii) response of peppers in terms of growth when using recycled wastewater subject to different growth media and hydrocarbon contamination; and (iii) the economic viability of different experimental set-ups in terms of marketable yield. Ortho-phosphate-phosphorus, ammonia-nitrogen, potassium and manganese concentrations in the irrigation water considerably exceeded the corresponding water quality thresholds. A high yield in terms of economic return (marketable yield expressed in monetary value) was linked to raw wastewater and an organic growth medium, while the plants grown in organic medium and wetlands of large aggregate size, high contact and resting times, diesel-spill contamination and low inflow loading rate produced the best fruits in terms of their dimensions and fresh weights, indicating the role of diesel in reducing too high nitrogen concentrations. PMID:26861370

Sanitization of contaminated footwear from onychomycosis patients using ozone gas: a novel adjunct therapy for treating onychomycosis and tinea pedis?

PubMed

Gupta, Aditya K; Brintnell, William C

2013-01-01

Ozone gas possesses antimicrobial properties against bacteria, viruses, and yeasts. Previously, we demonstrated the efficacy of ozone in killing ATCC strains of the dermatophyte fungi Trichophyton rubrum and Trichophyton mentagrophytes. To test the efficacy of ozone gas in sanitizing onychomycosis patient footwear contaminated with fungal material as a means of minimizing the risk of reinfection. Swabs of footwear from onychomycosis patients were cultured prior to and after ozone exposure to test the ability of ozone to sanitize these items. We identified contamination of footwear from most onychomycosis patients, a potential source of reinfection in these individuals. Furthermore, ozone gas was effective in sanitizing contaminated footwear. Ozone gas is effective in sanitizing footwear and represents a novel adjunct therapy to be used in conjunction with antifungal medications and/or devices to better treat onychomycosis and tinea pedis patients in both the short and the long term.

Adaptive Image Processing Methods for Improving Contaminant Detection Accuracy on Poultry Carcasses

USDA-ARS?s Scientific Manuscript database

Technical Abstract A real-time multispectral imaging system has demonstrated a science-based tool for fecal and ingesta contaminant detection during poultry processing. In order to implement this imaging system at commercial poultry processing industry, the false positives must be removed. For doi...

Removal of Inorganic, Microbial, and Particulate Contaminants from Secondary Treated Wastewater - Village Marine Tec. Expeditionary Unit Water Purifier, Generation 1 at Gallup, NM

EPA Science Inventory

The EUWP was developed to treat challenging water sources with variable turbidity, chemical contamination, and very high total dissolved solids (TDS) including seawater, during emergency situations when other water treatment facilities are incapacitated. The EUWP components are ...

Process for treating alkaline wastes for vitrification

DOEpatents

Hsu, Chia-lin W.

1994-01-01

According to its major aspects and broadly stated, the present invention is a process for treating alkaline waste materials, including high level radioactive wastes, for vitrification. The process involves adjusting the pH of the wastes with nitric acid, adding formic acid (or a process stream containing formic acid) to reduce mercury compounds to elemental mercury and MnO{sub 2} to the Mn(II) ion, and mixing with class formers to produce a melter feed. The process minimizes production of hydrogen due to noble metal-catalyzed formic acid decomposition during, treatment, while producing a redox-balanced feed for effective melter operation and a quality glass product. An important feature of the present invention is the use of different acidifying and reducing, agents to treat the wastes. The nitric acid acidifies the wastes to improve yield stress and supplies acid for various reactions; then the formic acid reduces mercury compounds to elemental mercury and MnO{sub 2}) to the Mn(II) ion. When the pH of the waste is lower, reduction of mercury compounds and MnO{sub 2}) is faster and less formic acid is needed, and the production of hydrogen caused by catalytically-active noble metals is decreased.

Method for treatment of soils contaminated with organic pollutants

DOEpatents

Wickramanayake, Godage B.

1993-01-01

A method for treating soil contaminated by organic compounds wherein an ozone containing gas is treated with acid to increase the stability of the ozone in the soil environment and the treated ozone applied to the contaminated soil to decompose the organic compounds. The soil may be treated in situ or may be removed for treatment and refilled.

Method of in situ retrieval of contaminants or other substances using a barrier system and leaching solutions

DOEpatents

Nickelson, Reva A.; Walsh, Stephanie; Richardson, John G.; Dick, John R.; Sloan, Paul A.

2006-12-26

Processes and methods relating to treating contaminants and collecting desired substances from a zone of interest using subterranean collection and containment barriers. Tubular casings having interlock structures are used to create subterranean barriers for containing and treating buried waste and its effluents. The subterranean barrier includes an effluent collection system. Treatment solutions provided to the zone of interest pass therethrough and are collected by the barrier and treated or recovered, allowing on-site remediation. Barrier components may be used to in the treatment by collecting or removing contaminants or other materials from the zone of interest.

Processing liquid organic wastes at the NNL Preston laboratory

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

Coppersthwaite, Duncan; Greenwood, Howard; Docrat, Tahera

2013-07-01

Organic compounds of various kinds have been used in the nuclear industry for numerous duties in uranium chemical, metal and ceramic processing plants. In the course of the various operations undertaken, these organic compounds have become contaminated with uranic material, either accidentally or as an inevitable part of the process. Typically, the chemical/physical form and/or concentration of the uranic content of the organics has prevented disposal. In order to address the issue of contaminated liquid organic wastes, the National Nuclear Laboratory (NNL) has developed a suite of treatments designed to recover uranium and to render the waste suitable for disposal.more » The developed processes are operated at industrial scale via the NNL Preston Laboratory Residue Processing Plant. The Oil Waste Leaching (OWL) Process is a fully industrialised process used for the treatment of contaminated oils with approximately 200 tonnes of uranium contaminated oil being treated to date. The process was originally developed for the treatment of contaminated tributyl phosphate and odourless kerosene which had been adsorbed onto sawdust. However, over the years, the OWL process has been refined for a range of oils including 'water emulsifiable' cutting oils, lubricating oils, hydraulic oils/fluids and 'Fomblin' (fully fluorinated) oils. Chemically, the OWL process has proved capable of treating solvents as well as oils but the highly volatile/flammable nature of many solvents has required additional precautions compared with those required for oil treatment. These additional precautions led to the development of the Solvent Treatment Advanced Rig (STAR), an installation operated under an inert atmosphere. STAR is a small 'module' (100 dm{sup 3} volume) which allows the treatment of both water miscible and immiscible solvents. This paper discusses the challenges associated with the treatment of liquid organic wastes and the process developments which have allowed a wide range

Treatment options for low-level radiologically contaminated ORNL filtercake

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

Lee, Hom-Ti; Bostick, W.D.

1996-04-01

Water softening sludge (>4000 stored low level contaminated drums; 600 drums per year) generated by the ORNL Process Waste Treatment Plant must be treated, stabilized, and placed in safe storage/disposal. The sludge is primarily CaCO{sub 3} and is contaminated by low levels of {sup 90}Sr and {sup 137}Cs. In this study, microwave sintering and calcination were evaluated for treating the sludge. The microwave melting experiments showed promise: volume reductions were significant (3-5X), and the waste form was durable with glass additives (LiOH, fly ash). A commercial vendor using surrogate has demonstrated a melt mineralization process that yields a dense monolithicmore » waste form with a volume reduction factor (VR) of 7.7. Calcination of the sludge at 850-900 C yielded a VR of 2.5. Compaction at 4500 psi increased the VR to 4.2, but the compressed form is not dimensionally stable. Addition of paraffin helped consolidate fines and yielded a VR of 3.5. In conclusion, microwave melting or another form of vitrification is likely to be the best method; however for immediate implementation, the calculation/compaction/waxing process is viable.« less

Contamination control in hybrid microelectronic modules. Part 3: Specifications for coating material and process controls

NASA Technical Reports Server (NTRS)

Himmel, R. P.

1975-01-01

Resin systems for coating hybrids prior to hermetic sealing are described. The resin systems are a flexible silicone junction resin system and a flexible cycloaliphatic epoxy resin system. The coatings are intended for application to the hybrid after all the chips have been assembled and wire bonded, but prior to hermetic sealing of the package. The purpose of the coating is to control particulate contamination by immobilizing particles and by passivating the hybrid. Recommended process controls for the purpose of minimizing contamination in hybrid microcircuit packages are given. Emphasis is placed on those critical hybrid processing steps in which contamination is most likely to occur.

A signal processing framework for simultaneous detection of multiple environmental contaminants

NASA Astrophysics Data System (ADS)

Chakraborty, Subhadeep; Manahan, Michael P.; Mench, Matthew M.

2013-11-01

The possibility of large-scale attacks using chemical warfare agents (CWAs) has exposed the critical need for fundamental research enabling the reliable, unambiguous and early detection of trace CWAs and toxic industrial chemicals. This paper presents a unique approach for the identification and classification of simultaneously present multiple environmental contaminants by perturbing an electrochemical (EC) sensor with an oscillating potential for the extraction of statistically rich information from the current response. The dynamic response, being a function of the degree and mechanism of contamination, is then processed with a symbolic dynamic filter for the extraction of representative patterns, which are then classified using a trained neural network. The approach presented in this paper promises to extend the sensing power and sensitivity of these EC sensors by augmenting and complementing sensor technology with state-of-the-art embedded real-time signal processing capabilities.

Pilot-scale UV/H2O2 study for emerging organic contaminants decomposition.

PubMed

Chu, Xiaona; Xiao, Yan; Hu, Jiangyong; Quek, Elaine; Xie, Rongjin; Pang, Thomas; Xing, Yongjie

2016-03-01

Human behaviors including consumption of drugs and use of personal care products, climate change, increased international travel, and the advent of water reclamation for direct potable use have led to the introduction of significant amounts of emerging organic contaminants into the aqueous environment. In addition, the lower detection limits associated with improved scientific methods of chemical analysis have resulted in a recent increase in documented incidences of these contaminants which previously were not routinely monitored in water. Such contaminants may cause known or suspected adverse ecological and/or human health effects at very low concentrations. Conventional drinking water treatment processes may not effectively remove these organic contaminants. Advanced oxidation process (AOP) is a promising treatment process for the removal of most of these emerging organic contaminants, and has been accepted worldwide as a suitable treatment process. In this study, different groups of emerging contaminants were studied for decomposition efficiency using pilot-scale UV/H2O2 oxidation setup, including EDCs, PPCPs, taste and odor (T&O), and perfluorinated compounds. Results found that MP UV/H2O2 AOP was efficient in removing all the selected contaminants except perfluorinated compounds. Study of the kinetics of the process showed that both light absorption and quantum yield of each compound affected the decomposition performance. Analysis of water quality parameters of the treated water indicated that the outcome of both UV photolysis and UV/H2O2 processes can be affected by changes in the feed water quality.

[Contamination with genetically modified maize MON863 of processed foods on the market].

PubMed

Ohgiya, Yoko; Sakai, Masaaki; Miyashita, Taeko; Yano, Koichi

2009-06-01

Genetically modified maize MON863 (MON863), which has passed a safety examination in Japan, is commercially cultivated in the United States as a food and a resource for fuel. Maize is an anemophilous flower, which easily hybridizes. However, an official method for quantifying the content of MON863 has not been provided yet in Japan. We here examined MON863 contamination in maize-processed foods that had no labeling indicating of the use of genetically modified maize.From March 2006 to July 2008, we purchased 20 frozen maize products, 8 maize powder products, 7 canned maize products and 4 other maize processed foods. Three primer pairs named MON 863 primer, MON863-1, and M3/M4 for MON863-specific integrated cassette were used for qualitative polymerase chain reaction (PCR). A primer pair "SSIIb-3" for starch synthase gene was used to confirm the quality of extracted DNA. The starch synthase gene was detected in all samples. In qualitative tests, the MON863-specific fragments were detected in 7 (18%) maize powder products out of the 39 processed foods with all the three primer pairs.We concluded that various maize processed foods on the market were contaminated with MON863. It is important to accumulate further information on MON863 contamination in maize-processed foods that have no label indication of the use of genetically modified maize.

The activation energy of stabilised/solidified contaminated soils.

PubMed

Chitambira, B; Al-Tabbaa, A; Perera, A S R; Yu, X D

2007-03-15

Developing an understanding of the time-related performance of cement-treated materials is essential in understanding their durability and long-term effectiveness. A number of models have been developed to predict this time-related performance. One such model is the maturity concept which involves use of the 'global' activation energy which derives from the Arrhenius equation. The accurate assessment of the activation energy is essential in the realistic modelling of the accelerated ageing of cement-treated soils. Experimentally, this model is applied to a series of tests performed at different elevated temperatures. Experimental work, related to the results of a time-related performance on a contaminated site in the UK treated with in situ stabilisation/solidification was carried out. Three different cement-based grouts were used on two model site soils which were both contaminated with a number of heavy metals and a hydrocarbon. Uncontaminated soils were also tested. Elevated temperatures up to 60 degrees C and curing periods up to 90 days were used. The resulting global activation energies for the uncontaminated and contaminated soils were compared. Lower values were obtained for the contaminated soils reflecting the effect of the contaminants. The resulting equivalent ages for the uncontaminated and contaminated mixes tested were 5.1-7.4 and 0.8-4.1 years, respectively. This work shows how a specific set of contaminants affect the E(a) values for particular cementitious systems and how the maturity concept can be applied to cement-treated contaminated soils.

Mobilisation processes responsible for iron and manganese contamination of groundwater in Central Adriatic Italy.

PubMed

Palmucci, William; Rusi, Sergio; Di Curzio, Diego

2016-06-01

Iron and manganese are two of the most common contaminants that exceed the threshold imposed by international and national legislation. When these contamination occurs in groundwater, the use of the water resource is forbidden for any purposes. Several studies investigated these two metals in groundwater, but research focused in the Central Adriatic area are still lacking. Thus, the objective of this study is to identify the origin of Fe and Mn contamination in groundwater and the hydrogeochemical processes that can enrich aquifers with these metals. This work is based on hydrogeochemical and multivariate statistical analysis of analytical results undertaken on soils and groundwater. Fe and Mn contamination are widespread in the alluvial aquifers, and their distribution is regulated by local conditions (i.e. long residence time, presence of peat or organic-rich fine sediments or anthropic pollution) that control redox processes in the aquifers and favour the mobilisation of these two metals in groundwater. The concentration of iron and manganese identified within soil indicates that the latter are a concrete source of the two metals. Anthropic impact on Fe and Mn contamination of groundwater is not related to agricultural activities, but on the contrary, the contribution of hydrocarbons (e.g. spills) is evident.

Simulating Heterogeneous Infiltration and Contaminant leaching Processes at Chalk River, Ontario

NASA Astrophysics Data System (ADS)

Ali, M. A.; Ireson, A. M.; Keim, D.

2015-12-01

A study is conducted at a waste management area in Chalk River, Ontario to characterize flow and contaminant transport with the aim of contributing to improved hydrogeological risk assessment in the context of waste management. Field monitoring has been performed to gain insights into the unsaturated zone characteristics, moisture dynamics, and contaminant transport rates. The objective is to provide quantitative estimates of surface fluxes (quantification of infiltration and evaporation) and investigations of unsaturated zone processes controlling water infiltration and spatial variability in head distributions and flow rates. One particular issue is to examine the effectiveness of the clayey soil cap installed to prevent infiltration of water into the waste repository and the top sand soil cover above the clayey layer to divert the infiltrated water laterally. The spatial variability in the unsaturated zone properties and associated effects on water flow and contaminant transport observed at the site, have led to a concerted effort to develop improved model of flow and transport based on stochastic concepts. Results obtained through the unsaturated zone model investigations are combined with the hydrogeological and geochemical components and develop predictive tools to assess the long term fate of the contaminants at the waste management site.

Rapid disinfection of E-Coliform contaminated water using WO3 semiconductor catalyst by laser-induced photo-catalytic process.

PubMed

Gondal, Mohammed A; Khalil, Amjad

2008-04-01

Laser-induced photo-catalysis process using WO(3) semiconductor catalyst was applied for the study of disinfection effectiveness of E-coliform-contaminated water. For this purpose, wastewater polluted with E-coliform bacteria was exposed to 355 nm UV radiations generated by third harmonic of Nd: YAG laser in special glass cell with and without WO(3) catalyst. E-Coliform quantification was performed by direct plating method to obtain the efficiency of each disinfection treatment. The dependence of disinfection process on laser irradiation energy, amount of catalyst and duration of laser irradiation was also investigated. The disinfection with WO(3) was quite efficient inactivating E-coliforms. For inactivation of E-coliforms, less than 8 minutes' laser irradiation was required, so that, the treated water complies with the microbial standards for drinking water. This study opens the possibility of application of this simple method in rural areas of developing countries using solar radiation.

CONTAMINANTS AND REMEDIAL OPTIONS AT PESTICIDE SITES

EPA Science Inventory

Many types of soils, sediments, and sludges are contaminated with a wide variety of pesticides. ite-specific characteristics such as volume to be treated, extent of contamination, and applicable cleanup goals differ greatly, and contaminant toxicity, migration pathways, persisten...

ECOMAT INC. BIOLOGICAL DENITRIFICATION PROCESS, ITER

EPA Science Inventory

EcoMat, Inc. of Hayward, California (EcoMat) has developed an ex situ anoxic biofilter biodenitrification (BDN) process. The process uses specific biocarriers and bacteria to treat nitrate-contaminated water and employs a patented reactor that retains biocarrier within the syste...

REMOVAL OF PCBS FROM A CONTAMINATED SOIL USING CF-SYSTEMS SOLVENT EXTRACTION PROCESS

EPA Science Inventory

The US EPA's START team in cooperation with EPA's SITE program evaluated a pilot scale solvent extraction process developed by CF-Systems. This process uses liquified propane to extract organic contaminants from soils, sludges, and sediments. A pilot-scale evaluation was conducte...

MICROBIAL PROCESSES AFFECTING MONITORED NATURAL ATTENUATION OF CONTAMINANTS IN THE SUBSURFACE

EPA Science Inventory

Among the alternatives considered for the remediation of soil and ground water at hazardous wastes sites are the use of natural processes to reduce or remove the contaminants of concern. Under favorable conditions, the use of natural attenuation can result in significant cost sa...

Research of polishing process to control the iron contamination on the magnetorheological finished KDP crystal surface.

PubMed

Chen, Shaoshan; Li, Shengyi; Peng, Xiaoqiang; Hu, Hao; Tie, Guipeng

2015-02-20

A new nonaqueous and abrasive-free magnetorheological finishing (MRF) method is adopted for processing a KDP crystal. MRF polishing is easy to result in the embedding of carbonyl iron (CI) powders; meanwhile, Fe contamination on the KDP crystal surface will affect the laser induced damage threshold seriously. This paper puts forward an appropriate MRF polishing process to avoid the embedding. Polishing results show that the embedding of CI powders can be avoided by controlling the polishing parameters. Furthermore, on the KDP crystal surface, magnetorheological fluids residua inevitably exist after polishing and in which the Fe contamination cannot be removed completely by initial ultrasonic cleaning. To solve this problem, a kind of ion beam figuring (IBF) polishing is introduced to remove the impurity layer. Then the content of Fe element contamination and the depth of impurity elements are measured by time of flight secondary ion mass spectrometry. The measurement results show that there are no CI powders embedding in the MRF polished surface and no Fe contamination after the IBF polishing process, respectively. That verifies the feasibility of MRF polishing-IBF polishing (cleaning) for processing a KDP crystal.

Integrating phytoremediation, wetlands, spray irrigation, and prairie restoration to treat carbon tetrachloride contamination in a rural community.

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

LaFreniere, L. M.; Negri, M. C.; Sedivy, R. A.

2006-01-01

In a cooperative conservation effort, the U.S. Department of Agriculture is cleaning up a contaminated aquifer in a rural community and simultaneously improving the community's recreational and educational opportunities. While one component of the cleanup system irrigates school athletic fields that were parched and bare in previous summers, other components have created a nearby public recreational area. The USDA's other partners in this effort are the U.S. Department of Energy's Argonne National Laboratory (ANL) and the U.S. Environmental Protection Agency, Kansas State University, state regulators, local businesses, governmental units, and residents. The groundwater aquifer beneath Murdock, Nebraska, became contaminated withmore » carbon tetrachloride as the result of fumigation of grain stored decades ago in a USDA facility. Contaminant levels in the groundwater (up to 7,800 {micro}g/L at one time) precluded use of the aquifer for drinking water, and discharge of contaminated groundwater to a nearby creek posed health risks. Concentrations of carbon tetrachloride as high as 361 {micro}g/kg in subsurface soil indicated the presence of a soil source. Model simulations of potential leaching indicated that the source would continue to release contaminant for at least 80 years, and migration to the creek would continue after that. The USDA, ANL, and EPA developed an innovative cleanup system that combines multiple technologies. Near the contamination source, pumps extract contaminated groundwater and pass it through a spray irrigation system that dissipates the carbon tetrachloride harmlessly into the air. The treated water irrigates the school's athletic field, nurturing a healthy grassy surface. Supplementing the spray irrigation technology are more than 2,000 trees planted downstream from where the groundwater enters the creek. The trees accomplish phytoremediation by taking up contaminated water and breaking down carbon tetrachloride naturally. Native prairie

Effectiveness of an anaerobic granular activated carbon fluidized-bed bioreactor to treat soil wash fluids: a proposed strategy for remediating PCP/PAH contaminated soils.

PubMed

Koran, K M; Suidan, M T; Khodadoust, A P; Sorial, G A; Brenner, R C

2001-07-01

An integrated system has been developed to remediate soils contaminated with pentachlorophenol (PCP) and polycyclic aromatic hydrocarbons (PAHs). This system involves the coupling of two treatment technologies, soil-solvent washing and anaerobic biotreatment of the extract. Specifically, this study evaluated the effectiveness of a granular activated carbon (GAC) fluidized-bed reactor to treat a synthetic-waste stream of PCP and four PAHs (naphthalene, acenaphthene, pyrene, and benzo(b)fluoranthene) under anaerobic conditions. This waste stream was intended to simulate the wash fluids from a soil washing process treating soils from a wood-preserving site. The reactor achieved a removal efficiency of greater than 99.8% for PCP with conversion to its dechlorination intermediates averaging 46.5%. Effluent, carbon extraction, and isotherm data also indicate that naphthalene and acenaphthene were removed from the liquid phase with efficiencies of 86 and 93%, respectively. Effluent levels of pyrene and benzo(b)fluoranthene were extremely low due to the high-adsorptive capacity of GAC for these compounds. Experimental evidence does not suggest that the latter two compounds were biochemically transformed within the reactor.

Remediation of nitrate-contaminated groundwater by PRB-Electrokinetic integrated process.

PubMed

Ghaeminia, Mahdyar; Mokhtarani, Nader

2018-05-30

Activated carbon is used as a reactive media in Permeable Reactive Barrier (PRB) for the removal of inorganic contaminants such as nitrate from groundwater. Since removal rate by this media decreases by time and due to the high costs of excavation and replacement of new media, the usage of activated carbon as an adsorbent in PRB is limited. The present study aimed to solve this defect by integrating electrokinetic process and PRB, using in-situ regeneration of activated carbon. This research was carried out on a laboratory scale using synthetically contaminated water and modified activated carbon as a reactive media in PRB. The effects of pH, nitrate concentration, carbon to sand ratio, and also electric gradient on the performance of the process were evaluated, and optimal conditions were determined, to increase the system longevity. According to the results, by applying an electric gradient of 1.25 V cm -1 to the PRB alone process in optimum operating condition (135 mg L -1 initial nitrate concentration, flow rate of 2.3 L min -1 , pH = 6.8, and carbon to sand ratios of 1:1) the adsorbent capacity increased by 90%. Under these conditions, the integrated process could keep nitrate concentration in the effluent below the standard limit for about 111 h, while the PRB alone process could do the same job for about 59 h. Also, SEM analysis showed that by applying electrokinetic process, activated carbon was regenerated. Integration of electrokinetic process and PRB was also caused nitrate to transfer from activated carbon media into the soil layer above the system. This nitrate-rich soil has the potential for reuse in agricultural activities. Copyright © 2018 Elsevier Ltd. All rights reserved.

Rapid and effective decontamination of chlorophenol-contaminated soil by sorption into commercial polymers: concept demonstration and process modeling.

PubMed

Tomei, M Concetta; Mosca Angelucci, Domenica; Ademollo, Nicoletta; Daugulis, Andrew J

2015-03-01

Solid phase extraction performed with commercial polymer beads to treat soil contaminated by chlorophenols (4-chlorophenol, 2,4-dichlorophenol and pentachlorophenol) as single compounds and in a mixture has been investigated in this study. Soil-water-polymer partition tests were conducted to determine the relative affinities of single compounds in soil-water and polymer-water pairs. Subsequent soil extraction tests were performed with Hytrel 8206, the polymer showing the highest affinity for the tested chlorophenols. Factors that were examined were polymer type, moisture content, and contamination level. Increased moisture content (up to 100%) improved the extraction efficiency for all three compounds. Extraction tests at this upper level of moisture content showed removal efficiencies ≥70% for all the compounds and their ternary mixture, for 24 h of contact time, which is in contrast to the weeks and months, normally required for conventional ex situ remediation processes. A dynamic model characterizing the rate and extent of decontamination was also formulated, calibrated and validated with the experimental data. The proposed model, based on the simplified approach of "lumped parameters" for the mass transfer coefficients, provided very good predictions of the experimental data for the absorptive removal of contaminants from soil at different individual solute levels. Parameters evaluated from calibration by fitting of single compound data, have been successfully applied to predict mixture data, with differences between experimental and predicted data in all cases being ≤3%. Copyright © 2014 Elsevier Ltd. All rights reserved.

Eco-toxicity and metal contamination of paddy soil in an e-wastes recycling area.

PubMed

Jun-hui, Zhang; Hang, Min

2009-06-15

Paddy soil samples taken from different sites in an old primitive electronic-waste (e-waste) processing region were examined for eco-toxicity and metal contamination. Using the environmental quality standard for soils (China, Grade II) as reference, soil samples of two sites were weakly contaminated with trace metal, but site G was heavily contaminated with Cd (6.37 mg kg(-1)), and weakly contaminated with Cu (256.36 mg kg(-1)) and Zn (209.85 mg kg(-1)). Zn appeared to be strongly bound in the residual fraction (72.24-77.86%), no matter the soil was metal contaminated or not. However, more than 9% Cd and 16% Cu was present in the non-residual fraction in the metal contaminated soils than in the uncontaminated soil, especially for site G and site F. Compared with that of the control soil, the micronucleus rates of site G and site F soil treatments increased by 2.7-fold and 1.7-fold, respectively. Low germination rates were observed in site C (50%) and site G (50%) soil extraction treated rice seeds. The shortest root length (0.2377 cm) was observed in site G soil treated groups, which is only 37.57% of that of the control soil treated groups. All of the micronucleus ratio of Vicia faba root cells, rice germination rate and root length after treatment of soil extraction indicate the eco-toxicity in site F and G soils although the three indexes are different in sensitivity to soil metal contamination.

Contamination of soils with microbial pathogens originating from effluent water used for agricultural irrigation

NASA Astrophysics Data System (ADS)

Bernstein, N.

2009-04-01

The use of wastewater for agricultural irrigation is steadily increasing world-wide and due to shortages of fresh water is common today in most arid regions of the world. The use of treated wastewater for agricultural irrigation may result in soil exposure to pathogens, creating potential public health problems. A variety of human pathogens are present in raw sewage water. Although their concentrations decrease during the wastewater reclamation process, the secondary treated effluents most commonly used for irrigation today still contain bacterial human pathogens. A range of bacterial pathogens, introduced through contaminated irrigation water or manure, are capable of surviving for long periods in soil and water where they have the potential to contaminate crops in the field. Therefore, there is a risk of direct contamination of crops by human pathogens from the treated effluents used for irrigation, as well as a risk of indirect contamination of the crops from contaminated soil at the agricultural site. Contradictory to previous notion, recent studies have demonstrated that human pathogens can enter plants through their roots and translocate and survive in edible, aerial plant tissues. The practical implications of these new findings for food safety are still not clear, but no doubt reflect the pathogenic microorganisms' ability to survive and multiply in the irrigated soil, water, and the harvested edible crop.

The importance of quality control in validating concentrations of contaminants of emerging concern in source and treated drinking water samples.

PubMed

Batt, Angela L; Furlong, Edward T; Mash, Heath E; Glassmeyer, Susan T; Kolpin, Dana W

2017-02-01

A national-scale survey of 247 contaminants of emerging concern (CECs), including organic and inorganic chemical compounds, and microbial contaminants, was conducted in source and treated drinking water samples from 25 treatment plants across the United States. Multiple methods were used to determine these CECs, including six analytical methods to measure 174 pharmaceuticals, personal care products, and pesticides. A three-component quality assurance/quality control (QA/QC) program was designed for the subset of 174 CECs which allowed us to assess and compare performances of the methods used. The three components included: 1) a common field QA/QC protocol and sample design, 2) individual investigator-developed method-specific QA/QC protocols, and 3) a suite of 46 method comparison analytes that were determined in two or more analytical methods. Overall method performance for the 174 organic chemical CECs was assessed by comparing spiked recoveries in reagent, source, and treated water over a two-year period. In addition to the 247 CECs reported in the larger drinking water study, another 48 pharmaceutical compounds measured did not consistently meet predetermined quality standards. Methodologies that did not seem suitable for these analytes are overviewed. The need to exclude analytes based on method performance demonstrates the importance of additional QA/QC protocols. Published by Elsevier B.V.

Binding mechanism of patulin to heat-treated yeast cell.

PubMed

Guo, C; Yuan, Y; Yue, T; Hatab, S; Wang, Z

2012-12-01

This study aims to assess the removal mechanism of patulin using heat-treated Saccharomyces cerevisiae cells and identify the role of different cell wall components in the binding process. In order to understand the binding mechanism, viable cells, heat-treated cells, cell wall and intracellular extract were performed to assess their ability to remove patulin. Additionally, the effects of chemical and enzymatic treatments of yeast on the binding ability were tested. The results showed that there was no significant difference between viable (53·28%) and heat-treated yeast cells (51·71%) in patulin binding. In addition, the cell wall fraction decreased patulin by 35·05%, and the cell extract nearly failed to bind patulin. Treatments with protease E, methanol, formaldehyde, periodate or urea significantly decreased (P < 0·05) the ability of heat-treated cells to remove patulin. Fourier transform infrared (FTIR) analysis indicated that more functional groups were involved in the binding process of heat-treated cells. Polysaccharides and protein are important components of yeast cell wall involved in patulin removal. In addition, hydrophobic interactions play a major role in binding processes. Heat-treated S. cerevisiae cells could be used to control patulin contamination in the apple juice industry. Also, our results proof that the patulin removal process is based mainly on the adsorption not degradation. © 2012 The Society for Applied Microbiology.

MANAGING MICROBIAL CONTAMINATION IN URBAN WATERSHEDS

EPA Science Inventory

This paper presents different approaches for controlling pathogen contamination in urban watersheds for contamination resulting from point and diffuse sources. Point sources of pathogens can be treated by a disinfection technology of known effectiveness, and a desired reduction ...

MANAGING MICROBIAL CONTAMINATION IN URBAN WATERSHEDS

EPA Science Inventory

This paper presents different approaches for controlling pathogen contamination in urban watersheds for contamination resulting from point and diffuses sources. Point sources of pathogens can be treated by a disinfection technology of known effectiveness, and a desired reduction ...

Hydrous pyrolysis/oxidation process for in situ destruction of chlorinated hydrocarbon and fuel hydrocarbon contaminants in water and soil

DOEpatents

Knauss, Kevin G.; Copenhaver, Sally C.; Aines, Roger D.

2000-01-01

In situ hydrous pyrolysis/oxidation process is useful for in situ degradation of hydrocarbon water and soil contaminants. Fuel hydrocarbons, chlorinated hydrocarbons, polycyclic aromatic hydrocarbons, petroleum distillates and other organic contaminants present in the soil and water are degraded by the process involving hydrous pyrolysis/oxidation into non-toxic products of the degradation. The process uses heat which is distributed through soils and water, optionally combined with oxygen and/or hydrocarbon degradation catalysts, and is particularly useful for remediation of solvent, fuel or other industrially contaminated sites.

Assessing the effectiveness of a three-stage on-farm biobed in treating pesticide contaminated wastewater.

PubMed

Cooper, Richard J; Fitt, Peter; Hiscock, Kevin M; Lovett, Andrew A; Gumm, Lee; Dugdale, Steve J; Rambohul, Justin; Williamson, Antony; Noble, Lister; Beamish, James; Hovesen, Poul

2016-10-01

Agricultural point source pesticide pollution arising from contaminated machinery washings and accidental spillages pose a significant threat to river water and groundwater quality. In this study, we assess the effectiveness of a three-stage on-farm biobed for treating pesticide contaminated wastewater from a large (20 km(2)) commercial arable estate. The facility consisted of an enclosed machinery wash-down unit (stage 1), a 49 m(2) lined compost-straw-topsoil biobed (stage 2), and a 200 m(2) drainage field with a trickle irrigation system (stage 3). Pesticide concentrations were analysed in water samples collected fortnightly between November 2013 and November 2015 from the biobed input and output sumps and from 20 porous pots buried at 45 cm and 90 cm depth within the drainage field. The results revealed that the biobed removed 68-98% of individual pesticides within the contaminated washings, with mean total pesticide concentrations reducing by 91.6% between the biobed input and output sumps. Drainage field irrigation removed a further 68-99% of individual pesticides, with total mean pesticide concentrations reducing by 98.4% and 97.2% in the 45 cm and 90 cm depth porous pots, respectively. The average total pesticide concentration at 45 cm depth in the drainage field (57 μg L(-1)) was 760 times lower than the mean concentration recorded in the input sump (43,334 μg L(-1)). There was no evidence of seasonality in the efficiency of biobed pesticide removal, nor was there evidence of a decline in removal efficiency over the two-year monitoring period. However, higher mean total pesticide concentrations at 90 cm (102 μg L(-1)) relative to 45 cm (57 μg L(-1)) depth indicated an accumulation of pesticide residues deeper within the soil profile. Overall, the results presented here demonstrate that a three-stage biobed can successfully reduce pesticide pollution risk from contaminated machinery washings on a commercial farm. Copyright © 2016

Occurrence of rhodamine B contamination in capsicum caused by agricultural materials during the vegetation process.

PubMed

Gao, Wei; Wu, Naiying; Du, Jingjing; Zhou, Li; Lian, Yunhe; Wang, Lei; Liu, Dengshuai

2016-08-15

This paper reports on the environmental rhodamine B (RhB) contamination in capsicum caused by agricultural materials during the vegetation process. Ultra-performance liquid chromatography tandem mass spectrometry (UPLC-MS/MS) was applied to detect 64 capsicum samples from China, Peru, India and Burma. Results demonstrated that RhB was found in all samples at low concentrations (0.11-0.98 μg/kg), indicating RhB contamination in capsicums is probably a ubiquitous phenomenon. In addition, studies into soils, roots, stems and leaves in Handan of Hebei province, China showed that the whole ecologic chain had been contaminated with RhB with the highest levels in leaves. The investigation into the agricultural environment in Handan of Hebei province and Korla of Xinjiang province, China demonstrated that the appearances of RhB contamination in the tested capsicums are mainly due to the agricultural materials contamination. The study verified that environmental contamination should be an important origin for the RhB contamination in capsicum fruits. Copyright © 2016 Elsevier Ltd. All rights reserved.

Significance of treated agrowaste residue and autochthonous inoculates (Arbuscular mycorrhizal fungi and Bacillus cereus) on bacterial community structure and phytoextraction to remediate soils contaminated with heavy metals.

PubMed

Azcón, Rosario; Medina, Almudena; Roldán, Antonio; Biró, Borbála; Vivas, Astrid

2009-04-01

In this study, we analyzed the impact of treatments such as Aspergillus niger-treated sugar beet waste (SB), PO4(3-) fertilization and autochthonous inoculants [arbuscular mycorrhizal (AM) fungi and Bacillus cereus], on the bacterial community structure in a soils contaminated with heavy metals as well as, the effectiveness on plant growth (Trifolium repens). The inoculation with AM fungi in SB amended soil, increased plant growth similarly to PO4(3-) addition, and both treatments matched in P acquisition but bacterial biodiversity estimated by denaturing gradient gel electrophoresis of amplified 16S rDNA sequences, was more stimulated by the presence of the AM fungus than by PO4(3-) fertilization. The SB amendment plus AM inoculation increased the microbial diversity by 233% and also changed (by 215%) the structure of the bacterial community. The microbial inoculants and amendment used favoured plant growth and the phytoextraction process and concomitantly modified bacterial community in the rhizosphere; thus they can be used for remediation. Therefore, the understanding of such microbial ecological aspects is important for phytoremediation and the recovery of contaminated soils.

Contamination of salmon fillets and processing plants with spoilage bacteria.

PubMed

Møretrø, Trond; Moen, Birgitte; Heir, Even; Hansen, Anlaug Å; Langsrud, Solveig

2016-11-21

The processing environment of salmon processing plants represents a potential major source of bacteria causing spoilage of fresh salmon. In this study, we have identified major contamination routes of important spoilage associated species within the genera Pseudomonas, Shewanella and Photobacterium in pre-rigor processing of salmon. Bacterial counts and culture-independent 16S rRNA gene analysis on salmon fillet from seven processing plants showed higher levels of Pseudomonas spp. and Shewanella spp. in industrially processed fillets compared to salmon processed under strict hygienic conditions. Higher levels of Pseudomonas spp. and Shewanella spp. were found on fillets produced early on the production day compared to later processed fillets. The levels of Photobacterium spp. were not dependent on the processing method or time of processing. In follow-up studies of two plants, bacterial isolates (n=2101) from the in-plant processing environments (sanitized equipment/machines and seawater) and from salmon collected at different sites in the production were identified by partial 16S rRNA gene sequencing. Pseudomonas spp. dominated in equipment/machines after sanitation with 72 and 91% of samples from the two plants being Pseudomonas-positive. The phylogenetic analyses, based on partial 16S rRNA gene sequencing, showed 48 unique sequence profiles of Pseudomonas of which two were dominant. Only six profiles were found on both machines and in fillets in both plants. Shewanella spp. were found on machines after sanitation in the slaughter department while Photobacterium spp. were not detected after sanitation in any parts of the plants. Shewanella spp. and Photobacterium spp. were found on salmon in the slaughter departments. Shewanella was frequently present in seawater tanks used for bleeding/short term storage. In conclusion, this study provides new knowledge on the processing environment as a source of contamination of salmon fillets with Pseudomonas spp. and

Leaching of arsenic, copper and chromium from thermally treated soil.

PubMed

Kumpiene, Jurate; Nordmark, Désirée; Hamberg, Roger; Carabante, Ivan; Simanavičienė, Rūta; Aksamitauskas, Vladislovas Česlovas

2016-12-01

Thermal treatment, if properly performed, is an effective way of destroying organic compounds in contaminated soil, while impact on co-present inorganic contaminants varies depending on the element. Leaching of trace elements in thermally treated soil can be altered by co-combusting different types of materials. This study aimed at assessing changes in mobility of As, Cr and Cu in thermally treated soil as affected by addition of industrial by-products prior to soil combustion. Contaminated soil was mixed with either waste of gypsum boards, a steel processing residue (Fe 3 O 4 ), fly ash from wood and coal combustion or a steel abrasive (96.5% Fe 0 ). The mixes and unamended soil were thermally treated at 800 °C and divided into a fine fraction <0.125 mm and a coarse fraction >0.125 mm to simulate particle separation occurring in thermal treatment plants. The impact of the treatment on element behaviour was assessed by a batch leaching test, X-ray absorption spectroscopy and dispersive X-ray spectrometry. The results suggest that thermal treatment is highly unfavourable for As contaminated soils as it increased both the As leaching in the fine particle size fraction and the mass of the fines (up to 92%). Soil amendment with Fe-containing compounds prior to the thermal treatment reduced As leaching to the levels acceptable for hazardous waste landfills, but only in the coarse fraction, which does not justify the usefulness of such treatment. Among the amendments used, gypsum most effectively reduced leaching of Cr and Cu in thermally treated soil and could be recommended for soils that do not contain As. Fly ash was the least effective amendment as it increased leaching of both Cr and As in majority of samples. Copyright © 2016 Elsevier Ltd. All rights reserved.

Decontamination and decommissioning plan for processing contaminated NaK at the INEL

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

LaRue, D.M.; Dolenc, M.R.

1986-09-01

This decontamination and decommissioning (D D) plan describes the work elements and project management plan for processing four containers of contaminated sodium/potassium (NaK) and returning the Army Reentry Vehicle Facility Site (ARVFS) to a reusable condition. The document reflects the management plan for this project before finalizing the conceptual design and preliminary prototype tests of the reaction kinetics. As a result, the safety, environmental, and accident analyses are addressed as preliminary assessments before completion at a later date. ARVFS contains an earth-covered bunker, a cylindrical test pit and metal shed, and a cable trench connecting the two items. The bunkermore » currently stores the four containers of NaK from the meltdown of the EBR-1 Mark II core. The D D project addressed in this plan involves processing the contaminated NaK and returning the ARVFS to potential reuse after cleanup.« less

Decontamination and decommissioning plan for processing contaminated NaK at the INEL

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

LaRue, D.M.; Dolenc, M.R.

1986-09-01

This decontamination and decommissioning (D&D) plan describes the work elements and project management plan for processing four containers of contaminated sodium/potassium (NaK) and returning the Army Reentry Vehicle Facility Site (ARVFS) to a reusable condition. The document reflects the management plan for this project before finalizing the conceptual design and preliminary prototype tests of the reaction kinetics. As a result, the safety, environmental, and accident analyses are addressed as preliminary assessments before completion at a later date. ARVFS contains an earth-covered bunker, a cylindrical test pit and metal shed, and a cable trench connecting the two items. The bunker currentlymore » stores the four containers of NaK from the meltdown of the EBR-1 Mark II core. The D&D project addressed in this plan involves processing the contaminated NaK and returning the ARVFS to potential reuse after cleanup.« less

PROCESS FOR TREATING VOLATILE METAL FLUORIDES

DOEpatents

Rudge, A.J.; Lowe, A.J.

1957-10-01

This patent relates to the purification of uranium hexafluoride, made by reacting the metal or its tetrafluoride with fluorine, from the frequently contained traces of hydrofluoric acid. According to the present process, UF/sub 6/ containing as an impurity a small amount of hydrofluoric acid, is treated to remove such impurity by contact with an anhydrous alkali metal fluoride such as sodium fluoride. In this way a non-volatile complex containing hydrofluoric acid and the alkali metal fluoride is formed, and the volatile UF /sub 6/ may then be removed by distillation.

Listeria monocytogenes in Food-Processing Facilities, Food Contamination, and Human Listeriosis: The Brazilian Scenario.

PubMed

Camargo, Anderson Carlos; Woodward, Joshua John; Call, Douglas Ruben; Nero, Luís Augusto

2017-11-01

Listeria monocytogenes is a foodborne pathogen that contaminates food-processing environments and persists within biofilms on equipment, utensils, floors, and drains, ultimately reaching final products by cross-contamination. This pathogen grows even under high salt conditions or refrigeration temperatures, remaining viable in various food products until the end of their shelf life. While the estimated incidence of listeriosis is lower than other enteric illnesses, infections caused by L. monocytogenes are more likely to lead to hospitalizations and fatalities. Despite the description of L. monocytogenes occurrence in Brazilian food-processing facilities and foods, there is a lack of consistent data regarding listeriosis cases and outbreaks directly associated with food consumption. Listeriosis requires rapid treatment with antibiotics and most drugs suitable for Gram-positive bacteria are effective against L. monocytogenes. Only a minority of clinical antibiotic-resistant L. monocytogenes strains have been described so far; whereas many strains recovered from food-processing facilities and foods exhibited resistance to antimicrobials not suitable against listeriosis. L. monocytogenes control in food industries is a challenge, demanding proper cleaning and application of sanitization procedures to eliminate this foodborne pathogen from the food-processing environment and ensure food safety. This review focuses on presenting the L. monocytogenes distribution in food-processing environment, food contamination, and control in the food industry, as well as the consequences of listeriosis to human health, providing a comparison of the current Brazilian situation with the international scenario.

Treatment of Chlorinated Aliphatic Contamination of Groundwater by Horizontal Recirculation Wells and by Constructed Vertical Flow Wetlands

DTIC Science & Technology

2002-03-01

groundwater laden with contaminants. Once the contaminated water is at the surface, it must be treated for contaminant destruction, generally by...treatment walls only work under very specific hydrogeologic conditions (relatively shallow water table, no seasonal fluctuations in groundwater flow...GCWs Elevation Schematic Water Table Contaminated Groundwater Contaminated Groundwater Treated Groundwater Treated Groundwater Reactive Porous Medium

Apparatus for treatment of soils contaminated with organic pollutants

DOEpatents

Wickramanayake, Godage B.

1993-01-01

An apparatus for treating soil contaminated by organic compounds wherein an ozone containing gas is treated with acid to increase the stability of the ozone in the soil environment and the treated ozone applied to the contaminated soil in a manner adapted to decompose the organic compounds; one embodiment of the apparatus comprises a means to supply ozone as a gas-ozone mixture, a stability means to treat ozone obtained from the supply and distribution means to apply the stabilized gas-ozone to soil. The soil may be treated in situ or may be removed for treatment and refilled.

Modeling the Kinetics of Contaminants Oxidation and the Generation of Manganese(III) in the Permanganate/Bisulfite Process.

PubMed

Sun, Bo; Dong, Hongyu; He, Di; Rao, Dandan; Guan, Xiaohong

2016-02-02

Permanganate can be activated by bisulfite to generate soluble Mn(III) (noncomplexed with ligands other than H2O and OH(-)) which oxidizes organic contaminants at extraordinarily high rates. However, the generation of Mn(III) in the permanganate/bisulfite (PM/BS) process and the reactivity of Mn(III) toward emerging contaminants have never been quantified. In this work, Mn(III) generated in the PM/BS process was shown to absorb at 230-290 nm for the first time and disproportionated more easily at higher pH, and thus, the utilization rate of Mn(III) for decomposing organic contaminant was low under alkaline conditions. A Mn(III) generation and utilization model was developed to get the second-order reaction rate parameters of benzene oxidation by soluble Mn(III), and then, benzene was chosen as the reference probe to build a competition kinetics method, which was employed to obtain the second-order rate constants of organic contaminants oxidation by soluble Mn(III). The results revealed that the second-order rate constants of aniline and bisphenol A oxidation by soluble Mn(III) were in the range of 10(5)-10(6) M(-1) s(-1). With the presence of soluble Mn(III) at micromolar concentration, contaminants could be oxidized with the observed rates several orders of magnitude higher than those by common oxidation processes, implying the great potential application of the PM/BS process in water and wastewater treatment.

Using Iron to Treat Chlorohydrocarbon-Contaminated Soil

NASA Technical Reports Server (NTRS)

Hitchens, G. Duncan; Hodko, Dalibor; Kim, Heekyung; Rogers, Tom; Singh, Waheguru Pal; Giletto, Anthony; Cisar, Alan

2004-01-01

A method of in situ remediation of soil contaminated with chlorinated hydrocarbon solvents involves injection of nanometer-size iron particles. The present method exploits a combination of prompt chemical remediation followed by longer-term enhanced bioremediation and, optionally, is practiced in conjunction with the method of bioremediation described earlier. Newly injected iron particles chemically reduce chlorinated hydrocarbons upon contact. Thereafter, in the presence of groundwater, the particles slowly corrode via chemical reactions that effect sustained release of dissolved hydrogen. The hydrogen serves as an electron donor, increasing the metabolic activity of the anaerobic bacteria and thereby sustaining bioremediation at a rate higher than the natural rate.

Contamination Revealed by Indicator Microorganism Levels during Veal Processing.

PubMed

Bosilevac, Joseph M; Wang, Rong; Luedtke, Brandon E; Wheeler, Tommy L; Koohmaraie, Mohammad

2016-08-01

During site visits of veal processors, the U.S. Department of Agriculture, Food Safety Inspection Service (FSIS) has reported processing deficiencies that likely contribute to increased levels of veal contamination. Here, we report the results of measuring aerobic plate count bacteria (APC), Enterobacteriaceae, coliforms (CF), and Escherichia coli during eight sample collections at five veal processors to assess contamination during the harvest of bob veal and formula-fed veal before (n = 5 plants) and after (n = 3 plants) changes to interventions and processing practices. Hides of veal calves at each plant had mean log CFU/100 cm(2) APC, Enterobacteriaceae, CF, and E. coli of 6.02 to 8.07, 2.95 to 5.24, 3.28 to 5.83, and 3.08 to 5.59, respectively. Preintervention carcasses had mean log CFU/100 cm(2) APC, Enterobacteriaceae, CF, and E. coli of 3.08 to 5.22, 1.16 to 3.47, 0.21 to 3.06, and -0.07 to 3.10, respectively, before and 2.72 to 4.50, 0.99 to 2.76, 0.69 to 2.26, and 0.33 to 2.12, respectively, after changes were made to improve sanitary dressing procedures. Final veal carcasses had mean log CFU/100 cm(2) APC, Enterobacteriaceae, CF, and E. coli of 0.36 to 2.84, -0.21 to 1.59, -0.23 to 1.59, and -0.38 to 1.45 before and 0.44 to 2.64, -0.16 to 1.33, -0.42 to 1.20, and 0.48 to 1.09 after changes were made to improve carcass-directed interventions. Whereas the improved dressing procedures resulted in improved carcass cleanliness, the changes to carcass-directed interventions were less successful, and veal processors are urged to use techniques that ensure uniform and consistent delivery of antimicrobials to carcasses. Analysis of results comparing bob veal to formula-fed veal found bob veal hides, preintervention carcasses, and final carcasses to have increased (P < 0.05) APC, Enterobacteriaceae, CF, and E. coli (with the exception of hide Enterobacteriaceae; P > 0.05) relative to formula fed veal. When both veal categories were harvested at the same plant on

ECOMAT INC. BIOLOGICAL DENIFTRICATION PROCESS; SITE TECHNOLOGY CAPSULE

EPA Science Inventory

EcoMat, Inc. of Hayward, California (EcoMat) has developed an ex situ anoxic biofilter biodenitrification (BDN) process. The process uses specific biocarriers and bacteria to treat nitrate-contaminated water and employs a patented reactor that retains biocarrier within the syste...

Methods for removing contaminants from algal oil

DOEpatents

Lupton, Francis Stephen

2016-09-27

Methods for removing contaminants from algal oil are provided. In an embodiment, a method comprises the steps of combining a sulfuric acid-aqueous solution that has a pH of about 1 or less with a contaminant-containing algal oil at treatment conditions effective to form an effluent. The effluent comprises a treated algal oil phase and contaminants in an acidic aqueous phase. The contaminants comprise metals, phosphorus, or combinations thereof. The acidic aqueous phase is removed from the effluent to form a contaminant-depleted algal oil.

Nationwide reconnaissance of contaminants of emerging ...

EPA Pesticide Factsheets

When chemical or microbial contaminants are assessed for potential effect or possible regulation in ambient and drinking waters, a critical first step is determining if the contaminants occur and if they are at concentrations that may cause human or ecological health concerns. To this end, source and treated drinking water samples from 29 drinking water treatment plants (DWTPs) were analyzed as part of a two-phase study to determine whether chemical and microbial constituents, many of which are considered contaminants of emerging concern, were detectable in the waters. Of the 84 chemicals monitored in the 9 Phase I DWTPs, 27 were detected at least once in the source water, and 21 were detected at least once in treated drinking water. In Phase II, which was a broader and more comprehensive assessment, 247 chemical and microbial analytes were measured in 25 DWTPs, with 148 detected at least once in the source water, and 121 detected at least once in the treated drinking water. The frequency of detection was often related to the analyte's contaminant class, as pharmaceuticals and anthropogenic waste indicators tended to be infrequently detected and more easily removed during treatment, while per and polyfluoroalkyl substances and inorganic constituents were both more frequently detected and, overall, more resistant to treatment. The data collected as part of this project will be used to help inform evaluation of unregulated contaminants in surface water, groundwate

Fate of pyrrolizidine alkaloids during processing of milk of cows treated with ragwort.

PubMed

de Nijs, Monique; Mulder, Patrick P J; Klijnstra, Mirjam D; Driehuis, Frank; Hoogenboom, Ron L A P

2017-12-01

To investigate the fate of pyrrolizidine alkaloids (PAs) during milk processing, milk of cows treated via rumen fistula with a mixture of 84% (w/w) ragwort (Jacobaea vulgaris, syn. Senecio jacobaea) and 16% narrow-leaved ragwort (Senecio inaequidens) was processed using laboratory scale heating systems with industrial settings. Pasteurised and sterilised (UHT) milk were produced, as well as set-type yoghurt and cheese. Samples were analysed for 29 PAs using LC-MS/MS, of which 11 PAs were detected above LOQ in the samples (0.1 µg l -1 ). Alterations in the PA concentration and composition between the standardised milk and the corresponding end-product(s) were evaluated. The heat treatments applied for pasteurisation and UHT sterilisation to prepare semi-skimmed consumption milk did not affect the PA levels in the end-products. In yoghurt, after fermentation of standardised milk (6 h, pH 4.4), 73% of total PAs were recovered. The PA concentration, specifically dehydrojacoline, was decreased, although not quantifiable, during cheese production. A further decrease of 38% during 6 weeks of ripening was observed. The results show that the PA concentration of natural contaminated cow's milk is not affected by heat treatment applied for pasteurised and sterilised milk, but that microbial fermentation of the milk leads to a lowered PA concentration in yoghurt and cheese. This is probably due to microbiological degradation, since PAs are fairly stable under acidic conditions.

L. monocytogenes in a cheese processing facility: Learning from contamination scenarios over three years of sampling.

PubMed

Rückerl, I; Muhterem-Uyar, M; Muri-Klinger, S; Wagner, K-H; Wagner, M; Stessl, B

2014-10-17

The aim of this study was to analyze the changing patterns of Listeria monocytogenes contamination in a cheese processing facility manufacturing a wide range of ready-to-eat products. Characterization of L. monocytogenes isolates included genotyping by pulsed-field gel electrophoresis (PFGE) and multi-locus sequence typing (MLST). Disinfectant-susceptibility tests and the assessment of L. monocytogenes survival in fresh cheese were also conducted. During the sampling period between 2010 and 2013, a total of 1284 environmental samples were investigated. Overall occurrence rates of Listeria spp. and L. monocytogenes were 21.9% and 19.5%, respectively. Identical L. monocytogenes genotypes were found in the food processing environment (FPE), raw materials and in products. Interventions after the sampling events changed contamination scenarios substantially. The high diversity of globally, widely distributed L. monocytogenes genotypes was reduced by identifying the major sources of contamination. Although susceptible to a broad range of disinfectants and cleaners, one dominant L. monocytogenes sequence type (ST) 5 could not be eradicated from drains and floors. Significantly, intense humidity and steam could be observed in all rooms and water residues were visible on floors due to increased cleaning strategies. This could explain the high L. monocytogenes contamination of the FPE (drains, shoes and floors) throughout the study (15.8%). The outcome of a challenge experiment in fresh cheese showed that L. monocytogenes could survive after 14days of storage at insufficient cooling temperatures (8 and 16°C). All efforts to reduce L. monocytogenes environmental contamination eventually led to a transition from dynamic to stable contamination scenarios. Consequently, implementation of systematic environmental monitoring via in-house systems should either aim for total avoidance of FPE colonization, or emphasize a first reduction of L. monocytogenes to sites where

INNOVATIVE PROCESSES FOR RECLAMATION OF CONTAMINATED SUBSURFACE ENVIRONMENTS

EPA Science Inventory

Research to better assess the capabilities and limitations of fixed-film bioreactors for removing selected organic contaminants from ground water or from contaminated vapor streams produced by air stripping of polluted ground water and by soil venting operations is described. ...

Cleanroom Garment Silicone Contamination

NASA Technical Reports Server (NTRS)

Geer, Wayne; Lepage, Colette

2006-01-01

The slide presentation reviews actions taken at Goddard Space Flight Center (GSFC) to eliminate contamination by silicone in clean rooms. Background information includes facilities and hardware affected by silicon contamination, a discussion of the negative aspects of silicone contamination, clean room garments, and how the problem was identified at GSFC. Actions taken by the GSFC Contamination Engineering Group and lessons learned are detailed. Results include: awareness of the silicone issue in laundry, increase in infrastructure and support of the testing lab, establishment of protocols for garment verification, closer relationship established with laundry and converter, specifications for laundry services and garments were strengthened, all consumables are tested before use in clean rooms, and established procedures were used to identify and treat silicone found on face masks.

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...

27 CFR 24.250 - Application for use of new treating material or process.

Code of Federal Regulations, 2011 CFR

2011-04-01

... from the testing program conducted by the chemical manufacturer demonstrating the function of the material or process; (7) A list of all chemicals used in compounding the treating material and the quantity... manufacturer or supplier of the treating material or process may be forwarded by the manufacturer or supplier...

27 CFR 24.250 - Application for use of new treating material or process.

Code of Federal Regulations, 2012 CFR

2012-04-01

... from the testing program conducted by the chemical manufacturer demonstrating the function of the material or process; (7) A list of all chemicals used in compounding the treating material and the quantity... manufacturer or supplier of the treating material or process may be forwarded by the manufacturer or supplier...

27 CFR 24.250 - Application for use of new treating material or process.

Code of Federal Regulations, 2013 CFR

2013-04-01

... from the testing program conducted by the chemical manufacturer demonstrating the function of the material or process; (7) A list of all chemicals used in compounding the treating material and the quantity... manufacturer or supplier of the treating material or process may be forwarded by the manufacturer or supplier...

27 CFR 24.250 - Application for use of new treating material or process.

Code of Federal Regulations, 2014 CFR

2014-04-01

... from the testing program conducted by the chemical manufacturer demonstrating the function of the material or process; (7) A list of all chemicals used in compounding the treating material and the quantity... manufacturer or supplier of the treating material or process may be forwarded by the manufacturer or supplier...

Exposure pathway evaluations for sites that processed asbestos-contaminated vermiculite.

PubMed

Anderson, Barbara A; Dearwent, Steve M; Durant, James T; Dyken, Jill J; Freed, Jennifer A; Moore, Susan McAfee; Wheeler, John S

2005-01-01

The Agency for Toxic Substances and Disease Registry (ATSDR) is currently evaluating the potential public health impacts associated with the processing of asbestos-contaminated vermiculite at various facilities around the country. Vermiculite ore contaminated with significant levels of asbestos was mined and milled in Libby, Montana, from the early 1920s until 1990. The majority of the Libby ore was then shipped to processing facilities for exfoliation. ATSDR initiated the National Asbestos Exposure Review (NAER) to identify and evaluate exposure pathways associated with these processing facilities. This manuscript details ATSDR's phased approach in addressing exposure potential around these sites. As this is an ongoing project, only the results from a selected set of completed site analyses are presented. Historical occupational exposures are the most significant exposure pathway for the site evaluations completed to date. Former workers also probably brought asbestos fibers home on their clothing, shoes, and hair, and their household contacts may have been exposed. Currently, most site-related worker and community exposure pathways have been eliminated. One community exposure pathway of indeterminate significance is the current exposure of individuals through direct contact with waste rock brought home for personal use as fill material, driveway surfacing, or soil amendment. Trace levels of asbestos are present in soil at many of the sites and buried waste rock has been discovered at a few sites; therefore, future worker and community exposure associated with disturbing on-site soil during construction or redevelopment at these sites is also a potential exposure pathway.

Process for vitrification of contaminated sodium oxide

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

Blair, H.T.; Mellinger, G.B.

1983-03-01

A glass composition was developed to accommodate 30 wt % sodium oxide and resist devitrification and leaching. An in-can melting process that is compatible with a comtaminated sodium calciner developed by Argonne National Laboratory was tested both on a laboratory and on an engineering scale and found to be viable. The Liquid Metal Fast Breeder Reactor experimental program continues to produce elemental sodium contaminated with radionuclides. This material is presently in temporary storage facilities because the current criterion will not permit alkali metals to be disposed of in shallow land burials. As a first step in treatment, Argonne National Laboratorymore » (ANL) has developed a calciner that will convert the sodium metal to an oxide. In work supported by the U.S. Department of Energy, Pacific Northwest Laboratory (PNL) is developing and demonstrating a process that is compatible with the calciner and facilities at ANL-West for incorporating sodium oxide into a glass. Glass, which normally contains sodium oxide, was chosen as the waste form because it is chemically durable and nondispersible. It is simple to produce, and the technology for incorporating nuclear wastes into glass is well developed.« less

Removal of bacterial contaminants and antibiotic resistance genes by conventional wastewater treatment processes in Saudi Arabia: Is the treated wastewater safe to reuse for agricultural irrigation?

PubMed

Al-Jassim, Nada; Ansari, Mohd Ikram; Harb, Moustapha; Hong, Pei-Ying

2015-04-15

This study aims to assess the removal efficiency of microbial contaminants in a local wastewater treatment plant over the duration of one year, and to assess the microbial risk associated with reusing treated wastewater in agricultural irrigation. The treatment process achieved 3.5 logs removal of heterotrophic bacteria and up to 3.5 logs removal of fecal coliforms. The final chlorinated effluent had 1.8 × 10(2) MPN/100 mL of fecal coliforms and fulfils the required quality for restricted irrigation. 16S rRNA gene-based high-throughput sequencing showed that several genera associated with opportunistic pathogens (e.g. Acinetobacter, Aeromonas, Arcobacter, Legionella, Mycobacterium, Neisseria, Pseudomonas and Streptococcus) were detected at relative abundance ranging from 0.014 to 21 % of the total microbial community in the influent. Among them, Pseudomonas spp. had the highest approximated cell number in the influent but decreased to less than 30 cells/100 mL in both types of effluent. A culture-based approach further revealed that Pseudomonas aeruginosa was mainly found in the influent and non-chlorinated effluent but was replaced by other Pseudomonas spp. in the chlorinated effluent. Aeromonas hydrophila could still be recovered in the chlorinated effluent. Quantitative microbial risk assessment (QMRA) determined that only chlorinated effluent should be permitted for use in agricultural irrigation as it achieved an acceptable annual microbial risk lower than 10(-4) arising from both P. aeruginosa and A. hydrophila. However, the proportion of bacterial isolates resistant to 6 types of antibiotics increased from 3.8% in the influent to 6.9% in the chlorinated effluent. Examples of these antibiotic-resistant isolates in the chlorinated effluent include Enterococcus and Enterobacter spp. Besides the presence of antibiotic-resistant bacterial isolates, tetracycline resistance genes tetO, tetQ, tetW, tetH, tetZ were also present at an average 2.5 × 10(2), 1.6 × 10

Bioremediation of lead contaminated soil with Rhodobacter sphaeroides.

PubMed

Li, Xiaomin; Peng, Weihua; Jia, Yingying; Lu, Lin; Fan, Wenhong

2016-08-01

Bioremediation with microorganisms is a promising technique for heavy metal contaminated soil. Rhodobacter sphaeroides was previously isolated from oil field injection water and used for bioremediation of lead (Pb) contaminated soil in the present study. Based on the investigation of the optimum culturing conditions and the tolerance to Pb, we employed the microorganism for the remediation of Pb contaminated soil simulated at different contamination levels. It was found that the optimum temperature, pH, and inoculum size for R. sphaeroides is 30-35 °C, 7, and 2 × 10(8) mL(-1), respectively. Rhodobacter sphaeroides did not remove the Pb from soil but did change its speciation. During the bioremediation process, more available fractions were transformed to less accessible and inert fractions; in particular, the exchangeable phase was dramatically decreased while the residual phase was substantially increased. A wheat seedling growing experiment showed that Pb phytoavailability was reduced in amended soils. Results inferred that the main mechanism by which R. sphaeroides treats Pb contaminated soil is the precipitation formation of inert compounds, including lead sulfate and lead sulfide. Although the Pb bioremediation efficiency on wheat was not very high (14.78% root and 24.01% in leaf), R. sphaeroides remains a promising alternative for Pb remediation in contaminated soil. Copyright © 2016 Elsevier Ltd. All rights reserved.

Salmonella typhimurium contamination of processed broiler chickens after a subclinical infection

PubMed Central

Knivett, V. A.

1971-01-01

A subclinical infection of Salmonella typhimurium in a broiler flock was investigated and attempts were made to eradicate the infection by treatment with furazolidone. One-quarter of the chickens were still infected after they had been through the processing plant. Washing in heavily chlorinated water reduced the number of contaminated carcasses. Infected chickens were also found in four other companion flocks on the same farm. PMID:4937856

Thermal-treated soil for mercury removal: Soil and phytotoxicity tests

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

Roh, Y.; Edwards, N.T.; Lee, S.Y.

Mercury (Hg) contamination of soils and sediments is one of many environmental problems at the Oak Ridge Reservation, Oak Ridge, TN. Mercury-contaminated soil from the Lower East Fork Poplar Creek (LEFPC) at the Oak Ridge Reservation was treated thermally to reduce Hg concentration to a below target level (20 mg kg{sup {minus}1}) as a pilot scale thermal treatment demonstration. As a part of performance evaluation, the soil characteristics and plant growth response of the untreated and treated soil were examined. The soil treated at 350 C retained most of its original soil properties, but the soil treated at 600 Cmore » exhibited considerable changes in mineralogical composition and physicochemical characteristics. Growth and physiological response of the three plant species radish (Raphanus sativus L.), fescue (Festuca arundinacea Schreb.), and oat (Avena sativa L.) indicated adverse effects of the thermal treatment. The addition of N fertilizer had beneficial effects in the 350 C treated soil, but had little beneficial effect in the 600 C treated soil. Some changes of soil characteristics induced by thermal treatment cannot be avoided. Soil characteristics and phytotoxicity test results strongly suggest that changes occurring following the 350 C treatment do not limit the use of the treated soil to refill the excavated site for full-scale remediation. The only problem with the 350 C treatment is that small amounts of Hg compounds (<15 mg kg{sup {minus}1}) remain in the soil and a processing cost of $45/Mg.« less

Removal of emerging contaminants in sewage water subjected to advanced oxidation with ozone.

PubMed

Ibáñez, M; Gracia-Lor, E; Bijlsma, L; Morales, E; Pastor, L; Hernández, F

2013-09-15

Advanced oxidation processes (AOP) based on ozone treatments, assisted by ultrasounds, have been investigated at a pilot-plant scale in order to evaluate the removal of emerging contaminants in sewage water. Around 60 emerging contaminants, mainly pharmaceuticals from different therapeutically classes and drugs of abuse, have been determined in urban wastewater samples (treated and untreated) by LC-MS/MS. In a first step, the removal efficiency of these contaminants in conventional sewage water treatment plants was evaluated. Our results indicate that most of the compounds were totally or partially removed during the treatment process of influent wastewater. Up to 30 contaminants were quantified in the influent and effluent samples analysed, being antibiotics, anti-inflammatories, cholesterol lowering statin drugs and angiotensin II receptor antagonists the most frequently detected. Regarding drugs of abuse, cocaine and its metabolite benzoylecgonine were the most frequent. In a second step, the effectiveness of AOP in the removal of emerging contaminants remaining in the effluent was evaluated. Ozone treatments have been proven to be highly efficient in the removal, notably decreasing the concentrations for most of the emerging contaminants present in the water samples. The use of ultrasounds, alone or assisting ozone treatments, has been shown less effective, being practically unnecessary. Copyright © 2013 Elsevier B.V. All rights reserved.

METHODS FOR MONITORING PUMP-AND-TREAT PERFORMANCE

EPA Science Inventory

Since the 1980s, numerous pump-and-treat systems have been constructed to: (1) hydraulically contain contaminated ground water, and/or (2) restore ground-water quality to meet a desired standard such as background quality or Maximum Contaminant Level (MCL) concentrations for drin...

Campylobacter spp. contamination of chicken carcasses during processing in relation to flock colonisation.

PubMed

Allen, V M; Bull, S A; Corry, J E L; Domingue, G; Jørgensen, F; Frost, J A; Whyte, R; Gonzalez, A; Elviss, N; Humphrey, T J

2007-01-01

The presence and numbers of campylobacters on chicken carcasses from 26 slaughter groups, originating from 22 single-house flocks and processed in four UK plants, were studied in relation to the level of flock colonisation determined by examining the caecal contents of at least ten birds per group. The prevalence of campylobacters on carcasses from five campylobacter-negative flocks processed just after other negative flocks was low (processed after fully colonised flocks. All carcasses from the remaining fully colonised flocks were contaminated with campylobacters, and they had significantly (P<0.001) higher numbers per carcass (average of 5.3 log(10) cfu; range: 1.3 to >8.0 log(10) cfu) than carcasses originating from low prevalence flocks (average of 2.3 log(10) cfu; range: <1.1 to 4.1 log(10) cfu). There was a reduction in the numbers of campylobacters on carcasses between plucking and chilling in eight of ten fully colonised flocks. In another eight flocks, a significant (P<0.001) decrease (0.8 log(10) cfu) in the number of campylobacters on carcasses from just before to after chilling was detected. Campylobacter spp. could be isolated from aerosols, particles and droplets in considerable numbers in the hanging-on, defeathering and evisceration areas but not in the chillers. This was the case even when campylobacters were not isolated from the target flock. Campylobacters on carcasses from two partly colonised flocks were either the same subtype, as determined by speciation, Multi-Locus Sequence Typing (MLST) and flaA Restricted Fragment Length Polymorphism (RFLP) typing, as those in the fully colonised flocks processed previously, although not necessarily the most prevalent ones; or were the same subtypes as those found in the caeca of the flock itself. The prevalences of the different

Stable isotope fractionation related to microbial nitrogen turnover in constructed wetlands treating contaminated groundwater

NASA Astrophysics Data System (ADS)

Voloshchenko, O.; Knoeller, K.

2013-12-01

To improve the efficiency of ground- and wastewater treatment in constructed wetlands (CWs), better understanding of the occurring processes is necessary. This research explores N-isotope fractionations associated with the removal of ammonium from contaminated groundwater in pilot-scale CWs downstream of the chemical industrial area Leuna, Germany. The groundwater at the site is contaminated mainly by organic (BTEX, MTBE) and inorganic compounds (ammonium). We assume that the anaerobic ammonium oxidation (ANAMMOX) plays an important role in nitrogen removal in these CWs. However, to date, interactions between processes of aerobic and anaerobic ammonium oxidation in CWs still have not been well explored. Especially, the importance of the ANAMMOX process for the nitrogen removal is generally accepted, but its role in CWs is quite unknown. For this aim, three CWs were chosen: planted horizontal subsurface flow (HSSF); unplanted HSSF, and floating plant root mat (FPRM). Water samples were taken at the inflow and outflow as well as from the pore space at different distances (1, 2.5 and 4 m) from the inlet and at different depths (20, 30 and 40 cm in the HSSF-CWs, 30 cm in the FPRM). Samples were collected in a time interval of 1 to 6 weeks during 1 year with the exception of the winter season. Physicochemical parameters, nitrogen isotope signatures of ammonium, as well as nitrogen and oxygen isotope signatures of nitrate were analysed. Within the CWs, spatial concentration gradients of the nitrogen species (ammonium and nitrate) are observed. N-isotope variations of ammonium and nitrate are interpreted according to the prevailing processes of the N-transformations. Based on isotope mass-balance approach microbial processes such as nitrification, denitrification, and ANAMMOX are quantified. DNA from biofilms at roots and gravel was extracted using FastDNA Spin Kit For Soil (MP Biomedicals). PCR, quantitative PCR, cloning, and sequencing were applied with the purpose of

Longitudinal study on the sources of Listeria monocytogenes contamination in cold-smoked salmon and its processing environment in Italy.

PubMed

Di Ciccio, Pierluigi; Meloni, Domenico; Festino, Anna Rita; Conter, Mauro; Zanardi, Emanuela; Ghidini, Sergio; Vergara, Alberto; Mazzette, Rina; Ianieri, Adriana

2012-08-01

The aim of the present study was to investigate the sources of Listeria monocytogenes contamination in a cold smoked salmon processing environment over a period of six years (2003-2008). A total of 170 samples of raw material, semi-processed, final product and processing surfaces at different production stages were tested for the presence of L. monocytogenes. The L. monocytogenes isolates were characterized by multiplex PCR for the analysis of virulence factors and for serogrouping. The routes of contamination over the six year period were traced by PFGE. L. monocytogenes was isolated from 24% of the raw salmon samples, 14% of the semi-processed products and 12% of the final products. Among the environmental samples, 16% were positive for L. monocytogenes. Serotyping yielded three serovars: 1/2a, 1/2b, 4b, with the majority belonging to serovars 1/2a (46%) and 1/2b (39%). PFGE yielded 14 profiles: two of them were repeatedly isolated in 2005-2006 and in 2007-2008 mainly from the processing environment and final products but also from raw materials. The results of this longitudinal study highlighted that contamination of smoked salmon occurs mainly during processing rather than originating from raw materials, even if raw fish can be a contamination source of the working environment. Molecular subtyping is critical for the identification of the contamination routes of L. monocytogenes and its niches into the production plant when control strategies must be implemented with the aim to reduce its prevalence during manufacturing. Copyright © 2012 Elsevier B.V. All rights reserved.

Applications analysis report: Silicate Technology Corporation's solidification/stabilization technology for organic and inorganic contaminants in soils

NASA Astrophysics Data System (ADS)

Bates, E.

1992-12-01

The STC demonstration was conducted under EPA's Superfund Innovative Technology Evaluation (SITE) Program in November, 1990, at the Selma Pressure Treating (SPT) wood preserving site in Selma, California. The SPT site was contaminated with both organics, predominantly pentachlorophenol (PCP), inorganics, mainly arsenic, chromium, and copper. Extensive sampling and analyses were performed on the waste both before and after treatment to compare physical, chemical, and leaching characteristics of raw and treated wastes. STC's contaminated soil treatment process was evaluated based on contaminant mobility measured by numerous leaching tests, structural integrity of the solidified material, measured by physical and engineering tests and morphological examinations; and economic analysis, using cost information supplied by STC and the results of the SITE demonstration, the vendor's design and test data, and other laboratory and field applications of the technology. It discusses the advantages, disadvantages, and limitations, as well as estimated costs of the technology.

Toxicological benchmarks for screening potential contaminants of concern for effects on soil and litter invertebrates and heterotrophic process

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

Will, M.E.; Suter, G.W. II

1994-09-01

One of the initial stages in ecological risk assessments for hazardous waste sites is the screening of contaminants to determine which of them are worthy of further consideration as {open_quotes}contaminants of potential concern.{close_quotes} This process is termed {open_quotes}contaminant screening.{close_quotes} It is performed by comparing measured ambient concentrations of chemicals to benchmark concentrations. Currently, no standard benchmark concentrations exist for assessing contaminants in soil with respect to their toxicity to soil- and litter-dwelling invertebrates, including earthworms, other micro- and macroinvertebrates, or heterotrophic bacteria and fungi. This report presents a standard method for deriving benchmarks for this purpose, sets of data concerningmore » effects of chemicals in soil on invertebrates and soil microbial processes, and benchmarks for chemicals potentially associated with United States Department of Energy sites. In addition, literature describing the experiments from which data were drawn for benchmark derivation. Chemicals that are found in soil at concentrations exceeding both the benchmarks and the background concentration for the soil type should be considered contaminants of potential concern.« less

Factors affecting the periapical healing process of endodontically treated teeth.

PubMed

Holland, Roberto; Gomes, João Eduardo; Cintra, Luciano Tavares Angelo; Queiroz, Índia Olinta de Azevedo; Estrela, Carlos

2017-01-01

Tissue repair is an essential process that reestablishes tissue integrity and regular function. Nevertheless, different therapeutic factors and clinical conditions may interfere in this process of periapical healing. This review aims to discuss the important therapeutic factors associated with the clinical protocol used during root canal treatment and to highlight the systemic conditions associated with the periapical healing process of endodontically treated teeth. The antibacterial strategies indicated in the conventional treatment of an inflamed and infected pulp and the modulation of the host's immune response may assist in tissue repair, if wound healing has been hindered by infection. Systemic conditions, such as diabetes mellitus and hypertension, can also inhibit wound healing. The success of root canal treatment is affected by the correct choice of clinical protocol. These factors are dependent on the sanitization process (instrumentation, irrigant solution, irrigating strategies, and intracanal dressing), the apical limit of the root canal preparation and obturation, and the quality of the sealer. The challenges affecting the healing process of endodontically treated teeth include control of the inflammation of pulp or infectious processes and simultaneous neutralization of unpredictable provocations to the periapical tissue. Along with these factors, one must understand the local and general clinical conditions (systemic health of the patient) that affect the outcome of root canal treatment prediction.

Process Design of Aluminum Tailor Heat Treated Blanks

PubMed Central

Kahrimanidis, Alexander; Lechner, Michael; Degner, Julia; Wortberg, Daniel; Merklein, Marion

2015-01-01

In many industrials field, especially in the automotive sector, there is a trend toward lightweight constructions in order to reduce the weight and thereby the CO2 and NOx emissions of the products. An auspicious approach within this context is the substitution of conventional deep drawing steel by precipitation hardenable aluminum alloys. However, based on the low formability, the application for complex stamping parts is challenging. Therefore, at the Institute of Manufacturing Technology, an innovative technology to enhance the forming limit of these lightweight materials was invented. The key idea of the so-called Tailor Heat Treated Blanks (THTB) is optimization of the mechanical properties by local heat treatment before the forming operation. An accurate description of material properties is crucial to predict the forming behavior of tailor heat treated blanks by simulation. Therefore, within in this research project, a holistic approach for the design of the THTB process in dependency of the main influencing parameters is presented and discussed in detail. The capability of the approach for the process development of complex forming operations is demonstrated by a comparison of local blank thickness of a tailgate with the corresponding results from simulation. PMID:28793727

Process Design of Aluminum Tailor Heat Treated Blanks.

PubMed

Kahrimanidis, Alexander; Lechner, Michael; Degner, Julia; Wortberg, Daniel; Merklein, Marion

2015-12-09

In many industrials field, especially in the automotive sector, there is a trend toward lightweight constructions in order to reduce the weight and thereby the CO₂ and NO x emissions of the products. An auspicious approach within this context is the substitution of conventional deep drawing steel by precipitation hardenable aluminum alloys. However, based on the low formability, the application for complex stamping parts is challenging. Therefore, at the Institute of Manufacturing Technology, an innovative technology to enhance the forming limit of these lightweight materials was invented. The key idea of the so-called Tailor Heat Treated Blanks (THTB) is optimization of the mechanical properties by local heat treatment before the forming operation. An accurate description of material properties is crucial to predict the forming behavior of tailor heat treated blanks by simulation. Therefore, within in this research project, a holistic approach for the design of the THTB process in dependency of the main influencing parameters is presented and discussed in detail. The capability of the approach for the process development of complex forming operations is demonstrated by a comparison of local blank thickness of a tailgate with the corresponding results from simulation.

Longitudinal analysis of bioaccumulative contaminants in freshwater fishes

USGS Publications Warehouse

Sun, Jielun; Kim, Y.; Schmitt, C.J.

2003-01-01

The National Contaminant Biomonitoring Program (NCBP) was initiated in 1967 as a component of the National Pesticide Monitoring program. It consists of periodic collection of freshwater fish and other samples and the analysis of the concentrations of persistent environmental contaminants in these samples. For the analysis, the common approach has been to apply the mixed two-way ANOVA model to combined data. A main disadvantage of this method is that it cannot give a detailed temporal trend of the concentrations since the data are grouped. In this paper, we present an alternative approach that performs a longitudinal analysis of the information using random effects models. In the new approach, no grouping is needed and the data are treated as samples from continuous stochastic processes, which seems more appropriate than ANOVA for the problem.

Sources of Salmonella on broiler carcasses during transportation and processing: modes of contamination and methods of control.

PubMed

Corry, Janet E L; Allen, V M; Hudson, W R; Breslin, M F; Davies, R H

2002-01-01

The prevalence and types of salmonella in broiler chickens during transportation and during slaughter and dressing were studied. This was part of a comprehensive investigation of salmonellas in two UK poultry companies, which aimed to find the origins and mechanisms of salmonella contamination. Salmonellas were isolated using cultural methods. Serovars of Salmonella detected during rearing were usually also found in a small proportion of birds on the day of slaughter and on the carcasses at various points during processing. There was little evidence of salmonellas spreading to large numbers of carcasses during processing. Many serovars found in the feedmills or hatcheries were also detected in the birds during rearing and/or slaughter. Transport crates were contaminated with salmonellas after washing and disinfection. Prevalence of salmonellas fell in the two companies during this survey. A small number of serovars predominated in the processing plants of each company. These serovars originated from the feed mills. Reasons for transport crate contamination were: (1) inadequate cleaning, resulting in residual faecal soiling; (2) disinfectant concentration and temperature of disinfectant too low; (3) contaminated recycled flume water used to soak the crates. Efforts to control salmonella infection in broilers need to concentrate on crate cleaning and disinfection and hygiene in the feed mills.

Automated processing of forensic casework samples using robotic workstations equipped with nondisposable tips: contamination prevention.

PubMed

Frégeau, Chantal J; Lett, C Marc; Elliott, Jim; Yensen, Craig; Fourney, Ron M

2008-05-01

An automated process has been developed for the analysis of forensic casework samples using TECAN Genesis RSP 150/8 or Freedom EVO liquid handling workstations equipped exclusively with nondisposable tips. Robot tip cleaning routines have been incorporated strategically within the DNA extraction process as well as at the end of each session. Alternative options were examined for cleaning the tips and different strategies were employed to verify cross-contamination. A 2% sodium hypochlorite wash (1/5th dilution of the 10.8% commercial bleach stock) proved to be the best overall approach for preventing cross-contamination of samples processed using our automated protocol. The bleach wash steps do not adversely impact the short tandem repeat (STR) profiles developed from DNA extracted robotically and allow for major cost savings through the implementation of fixed tips. We have demonstrated that robotic workstations equipped with fixed pipette tips can be used with confidence with properly designed tip washing routines to process casework samples using an adapted magnetic bead extraction protocol.

Electrowinning process with electrode compartment to avoid contamination of electrolyte

DOEpatents

Poa, Davis S.; Pierce, R. Dean; Mulcahey, Thomas P.; Johnson, Gerald K.

1993-01-01

An electrolytic process and apparatus for reducing calcium oxide in a molten electrolyte of CaCl.sub.2 -CaF.sub.2 with a graphite anode in which particles or other contamination from the anode is restricted by the use of a porous barrier in the form of a basket surrounding the anode which may be removed from the electrolyte to burn the graphite particles, and wherein the calcium oxide feed is introduced to the anode compartment to increase the oxygen ion concentration at the anode.

Reduction of carbon contamination during the melting process of Czochralski silicon crystal growth

NASA Astrophysics Data System (ADS)

Liu, Xin; Gao, Bing; Nakano, Satoshi; Kakimoto, Koichi

2017-09-01

Generation, incorporation, and accumulation of carbon (C) were investigated by transient global simulations of heat and mass transport during the melting process of Czochralski silicon (CZ-Si) crystal growth. Contact reaction between the quartz crucible and graphite susceptor was introduced as an extra origin of C contamination. The contribution of the contact reaction on C accumulation is affected by the back diffusion of C monoxide (CO) from the gap between the gas-guide and the crucible. The effect of the gas-guide coating on C reduction was elucidated by taking the reaction between the silicon carbide (SiC) coating and gaseous Si monoxide (SiO) into account. Application of the SiC coating on the gas-guide could effectively reduce the C contamination because of its higher thermochemical stability relative to that of graphite. Gas flow control on the back diffusion of the generated CO was examined by the parametric study of argon gas flow rate. Generation and back diffusion of CO were both effectively suppressed by the increase in the gas flow rate because of the high Péclet number of species transport. Strategies for C content reduction were discussed by analyzing the mechanisms of C accumulation process. According to the elucidated mechanisms of C accumulation, the final C content depends on the growth duration and contamination flux at the gas/melt interface.

Contaminated water treatment

NASA Technical Reports Server (NTRS)

Gormly, Sherwin J. (Inventor); Flynn, Michael T. (Inventor)

2010-01-01

Method and system for processing of a liquid ("contaminant liquid") containing water and containing urine and/or other contaminants in a two step process. Urine, or a contaminated liquid similar to and/or containing urine and thus having a relatively high salt and urea content is passed through an activated carbon filter to provide a resulting liquid, to remove most of the organic molecules. The resulting liquid is passed through a semipermeable membrane from a membrane first side to a membrane second side, where a fortified drink having a lower water concentration (higher osmotic potential) than the resulting liquid is positioned. Osmotic pressure differential causes the water, but not most of the remaining inorganic (salts) contaminant(s) to pass through the membrane to the fortified drink. Optionally, the resulting liquid is allowed to precipitate additional organic molecules before passage through the membrane.

In situ removal of contamination from soil

DOEpatents

Lindgren, E.R.; Brady, P.V.

1997-10-14

A process of remediation of cationic heavy metal contamination from soil utilizes gas phase manipulation to inhibit biodegradation of a chelating agent that is used in an electrokinesis process to remove the contamination. The process also uses further gas phase manipulation to stimulate biodegradation of the chelating agent after the contamination has been removed. The process ensures that the chelating agent is not attacked by bioorganisms in the soil prior to removal of the contamination, and that the chelating agent does not remain as a new contaminant after the process is completed. 5 figs.

Application of Fenton process to remove organic matter and PCBs from waste (fuller's earth) contaminated with insulating oil.

PubMed

da Silva, Milady Renata Apolinário; Rodrigues, Eduardo de Oliveira; Espanhol-Soares, Melina; Silva, Flavio Soares; Kondo, Márcia Matiko; Gimenes, Rossano

2018-01-09

Polychlorinated biphenyls (PCBs) are carcinogenic to humans and can be found in fuller's earth used for the treatment of used transformer oil. This work describes an optimization of the Fenton process for the removal of contaminants from fuller's earth. The effects of pH (2.5 and 4.0), [H 2 O 2 ] (1.47 and 2.07 mol L -1 ), and [Fe 2+ ] (1.7 and 40 mmol L -1 ) were studied. The Fenton process efficiency was monitored using the decreases in the chemical oxygen demand (COD) and the concentrations of oil and grease, total carbon (TC), PCBs, and H 2 O 2 . The fuller's earth contaminated with insulating oil presented 35% (w/w) of TC, 34% (w/w) of oil and grease, 297.0 g L -1 COD, and 64 mg of PCBs per kg. The material could therefore be considered a dangerous waste. After Fenton treatment, using a slurry mode, there was a removal of 55% of COD, 20% of oil and grease, and 20% of TC, achieved at pH 2.5 using 2.07 mol L -1 of H 2 O 2 and 40.0 mmol L -1 of Fe 2+ . No PCBs were detected in the samples after the Fenton treatment, even using smaller amounts of Fenton reagents (1.47 mol L -1 of H 2 O 2 , 1.7 mmol L -1 of Fe 2+ , pH 2.5). The results indicated that the treated fuller's earth was free from PCB residues and could be disposed of in a simple landfill, in accordance with Brazilian PCB regulations.

Cleaning Processes across NASA Centers

NASA Technical Reports Server (NTRS)

Hammond, John M.

2010-01-01

All significant surfaces of the hardware must be pre-cleaned to remove dirt, grit, scale, corrosion, grease, oil and other foreign matter prior to any final precision cleaning process. Metallic parts shall be surface treated (cleaned, passivated, pickled and/or coated) as necessary to prevent latent corrosion and contamination.

Pervaporation process and use in treating waste stream from glycol dehydrator

DOEpatents

Kaschemekat, Jurgen; Baker, Richard W.

1994-01-01

Pervaporation processes and apparatus with few moving parts. Ideally, only one pump is used to provide essentially all of the motive power and driving force needed. The process is particularly useful for handling small streams with flow rates less than about 700 gpd. Specifically, the process can be used to treat waste streams from glycol dehydrator regeneration units.

Bioremediation of poly-aromatic hydrocarbon (PAH)-contaminated soil by composting

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

Loick, N.; Hobbs, P.J.; Hale, M.D.C.

2009-07-01

This paper presents a comprehensive and critical review of research on different co-composting approaches to bioremediate hydrocarbon contaminated soil, organisms that have been found to degrade PAHs, and PAH breakdown products. Advantages and limitations of using certain groups of organisms and recommended areas of further research effort are identified. Studies investigating the use of composting techniques to treat contaminated soil are broad ranging and differ in many respects, which makes comparison of the different approaches very difficult. Many studies have investigated the use of specific bio-additives in the form of bacteria or fungi with the aim of accelerating contaminant removal;more » however, few have employed microbial consortia containing organisms from both kingdoms despite knowledge suggesting synergistic relationships exist between them in contaminant removal. Recommendations suggest that further studies should attempt to systemize the investigations of composting approaches to bio-remediate PAH-contaminated soil, to focus on harnessing the biodegradative capacity of both bacteria and fungi to create a cooperative environment for PAH degradation, and to further investigate the array of PAHs that can be lost during the composting process by either leaching or volatilization.« less

Radioactive contamination of the Balchug (Upper Yenisey) floodplain, Russia in relation to sedimentation processes and geomorphology.

PubMed

Linnik, V G; Brown, J E; Dowdall, M; Potapov, V N; Surkov, V V; Korobova, E M; Volosov, A G; Vakulovsky, S M; Tertyshnik, E G

2005-03-01

The radioactive contamination of a riverine floodplain, heavily influenced by discharges from Krasnoyarsk-26, has been studied with respect to sedimentation processes and the geomorphology of the Upper Yenisey floodplain. The study was effected by implementation of a regime of in situ observations and measurements, sampling, and the interpretation of satellite images. The results of the study indicate that on the Balchug Bypass Floodplain, radionuclide contamination is primarily influenced by the thickness of the deposited sediments, and the area can be considered as two depositional environments. The Balchug floodplain area was contaminated due to sedimentation of radionuclide-contaminated alluvium, whose depositional regime significantly changed after the construction of a hydroelectric power station in 1967. Contamination levels are lower on the upstream part of the floodplain where sediment depth is less than 0.2-0.3 m, and this contamination started to accumulate in 1967, while the downstream part of the floodplain, exhibiting deeper deposits, displays higher levels of radionuclide contamination because radionuclides began to deposit here in 1958 when the Krasnoyarsk-26 Mining and Chemical Combine (KMCC) commenced operation. Radionuclide contamination of the floodplain is also related to the elevation of the floodplain, higher regions of the floodplain typically having lower contamination than low-lying areas, which tend to be frequently inundated with sediments being deposited during such inundations. Local relief, its orientation, and vegetation cover have also combined to form sediment traps with significantly higher radionuclide contamination. Lithological analysis combined with radiometric assay indicates a total 137Cs floodplain inventory of 33.7 GBq.

SUMMARY OF WATERBORNE ILLNESS TRANSMITTED THROUGH CONTAMINATED GROUNDWATER

EPA Science Inventory

The use of contaminated, untreated or inadequately treated groundwater was responsible for 51 percent of all waterborne outbreaks and 40 percent of all waterborne illness reported in the United States during the period 1971-82. Contaminated, untreated or inadequately disinfected ...

Reuse of Textile Dyeing Effluents Treated with Coupled Nanofiltration and Electrochemical Processes

PubMed Central

Buscio, Valentina; García-Jiménez, María; Vilaseca, Mercè; López-Grimau, Victor; Crespi, Martí; Gutiérrez-Bouzán, Carmen

2016-01-01

The reactive dye Cibacron Yellow S-3R was selected to evaluate the feasibility of combining nanofiltration membranes with electrochemical processes to treat textile wastewater. Synthetic dyeing effluents were treated by means of two nanofiltration membranes, Hydracore10 and Hydracore50. Up to 98% of dye removal was achieved. The influence of salt concentration and pH on membrane treatment was studied. The best dye removal yield was achieved at pH 3 in the presence of 60 g/L of NaCl. After the membrane filtration, the concentrate containing high dye concentration was treated by means of an electrochemical process at three different current densities: 33, 83, and 166 mA/cm2. Results showed a lineal relationship between treatment time and applied current density. Both permeates and electrochemically-decoloured effluents were reused in new dyeing processes (100% of permeate and 70% of decoloured concentrates). Dyed fabrics were evaluated with respect to original dyeing. Colour differences were found to be into the acceptance range. PMID:28773614

Tracing the contamination origin of coliform bacteria in two small food-processing factories.

PubMed

Tominaga, Tatsuya; Sekine, Masahiro; Oyaizu, Hiroshi

2008-09-01

The objective of this study was to trace contamination sources of coliform bacteria by comparing the types of coliforms between food samples and the processing environments in two small food-processing factories (factories A and B). Fermentation tests of five sugars enabled the successful classification of 16 representative type strains into eight distinct groups. The grouping procedure was then applied to comparison of the coliform flora between food products and various locations in their processing environments. The consistency between each food and the tested locations was evaluated using the Jaccard index. The air conditioner and refrigeration room floor in factory A showed an index of 1.00, while the shaping machine in factory B showed an index of 0.98, indicating that these locations could be contamination sources. The validity of our results was confirmed by randomly amplified polymorphic DNA, which showed 100% matched profiles between the air conditioner and the food in factory A, and highly matched profiles between the machine and the food in factory B. This method for comparing the coliform flora between food and environments has the potential to be a reliable tracing tool for various food industries.

Factors affecting the periapical healing process of endodontically treated teeth

PubMed Central

Holland, Roberto; Gomes, João Eduardo; Cintra, Luciano Tavares Angelo; Queiroz, Índia Olinta de Azevedo; Estrela, Carlos

2017-01-01

Abstract Tissue repair is an essential process that reestablishes tissue integrity and regular function. Nevertheless, different therapeutic factors and clinical conditions may interfere in this process of periapical healing. This review aims to discuss the important therapeutic factors associated with the clinical protocol used during root canal treatment and to highlight the systemic conditions associated with the periapical healing process of endodontically treated teeth. The antibacterial strategies indicated in the conventional treatment of an inflamed and infected pulp and the modulation of the host's immune response may assist in tissue repair, if wound healing has been hindered by infection. Systemic conditions, such as diabetes mellitus and hypertension, can also inhibit wound healing. The success of root canal treatment is affected by the correct choice of clinical protocol. These factors are dependent on the sanitization process (instrumentation, irrigant solution, irrigating strategies, and intracanal dressing), the apical limit of the root canal preparation and obturation, and the quality of the sealer. The challenges affecting the healing process of endodontically treated teeth include control of the inflammation of pulp or infectious processes and simultaneous neutralization of unpredictable provocations to the periapical tissue. Along with these factors, one must understand the local and general clinical conditions (systemic health of the patient) that affect the outcome of root canal treatment prediction. PMID:29069143

Movement and fate of solutes in a plume of sewage-contaminated ground water, Cape Cod, Massachusetts

USGS Publications Warehouse

LeBlanc, D. R.

1984-01-01

The U.S. Geological Survey (USGS) has begun a nationwide program to study the fate of toxic wastes in groundwater. Several sites where groundwater is known to be contaminated are being studied by interdisciplinary teams of geohydrologists, chemists, and microbiologists. The objective of these studies is to obtain a thorough quantitative understanding of the physical, chemical, and biological processes of contaminant generation, migration, and attenuation in aquifers. One of the sites being studied by the USGS under this program is a plume of sewage contaminated groundwater on Cape Cod, Massachusetts. The plume was formed by land disposal of treated sewage to a glacial outwash aquifer since 1936. This report summarizes results obtained during the first year of research at the Cape Cod s under the USGS Toxic-Waste Ground-Water Contamination Program. The seven papers included in this volume were presented at the Toxic Waste Technical Meeting, Tucson, Arizona, in March 1984. They provide an integrated view of the subsurface distribution of contaminants based on the first year of research and discuss hypotheses concerning the transport processes that affect the movement of contaminants in the plume. (See W89-09053 thru W89-09059) (Lantz-PTT)

Catalytic destruction of groundwater contaminants in reactive extraction wells

DOEpatents

McNab, Jr., Walt W.; Reinhard, Martin

2002-01-01

A system for remediating groundwater contaminated with halogenated solvents, certain metals and other inorganic species based on catalytic reduction reactions within reactive well bores. The groundwater treatment uses dissolved hydrogen as a reducing agent in the presence of a metal catalyst, such a palladium, to reduce halogenated solvents (as well as other substituted organic compounds) to harmless species (e.g., ethane or methane) and immobilize certain metals to low valence states. The reactive wells function by removing water from a contaminated water-bearing zone, treating contaminants with a well bore using catalytic reduction, and then reinjecting the treated effluent into an adjacent water-bearing zone. This system offers the advantages of a compact design with a minimal surface footprint (surface facilities) and the destruction of a broad suite of contaminants without generating secondary waste streams.

NATURAL ARSENIC CONTAMINATION OF HOLOCENE ALLUVIAL AQUIFERS BY LINKED TECTONIC, WEATHERING, AND MICROBIAL PROCESSES

EPA Science Inventory

Linked tectonic, geochemical, and biologic processes lead to natural arsenic contamination of groundwater in Holocene alluvial aquifers, which are the main threat to human health around the world. These groundwaters are commonly found a long distance from their ultimate source of...

Natural attenuation processes for remediation of arsenic contaminated soils and groundwater.

PubMed

Wang, Suiling; Mulligan, Catherine N

2006-12-01

Arsenic (As) contamination presents a hazard in many countries. Natural attenuation (NA) of As-contaminated soils and groundwater may be a cost-effective in situ remedial option. It relies on the site intrinsic assimilative capacity and allows in-place cleanup. Sorption to solid phases is the principal mechanism immobilizing As in soils and removing it from groundwater. Hydroxides of iron, aluminum and manganese, clay and sulfide minerals, and natural organic matter are commonly associated with soils and aquifer sediments, and have been shown to be significant As adsorbents. The extent of sorption is influenced by As speciation and the site geochemical conditions such as pH, redox potential, and the co-occurring ions. Microbial activity may catalyze the transformation of As species, or mediate redox reactions thus influencing As mobility. Plants that are capable of hyperaccumulating As may translocate As from contaminated soils and groundwater to their tissues, providing the basis for phytoremediation. However, NA is subject to hydrological changes and may take substantial periods of time, thus requiring long-term monitoring. The current understanding of As NA processes remains limited. Sufficient site characterization is critical to the success of NA. Further research is required to develop conceptual and mathematical models to predict the fate and transport of As and to evaluate the site NA capacity. Engineering enhanced NA using environmentally benign products may be an effective alternative.

Biologically active filters - An advanced water treatment process for contaminants of emerging concern.

PubMed

Zhang, Shuangyi; Gitungo, Stephen W; Axe, Lisa; Raczko, Robert F; Dyksen, John E

2017-05-01

With the increasing concern of contaminants of emerging concern (CECs) in source water, this study examines the hypothesis that existing filters in water treatment plants can be converted to biologically active filters (BAFs) to treat these compounds. Removals through bench-scale BAFs were evaluated as a function of media, granular activated carbon (GAC) and dual media, empty bed contact time (EBCT), and pre-ozonation. For GAC BAFs, greater oxygen consumption, increased pH drop, and greater dissolved organic carbon removal normalized to adenosine triphosphate (ATP) were observed indicating increased microbial activity as compared to anthracite/sand dual media BAFs. ATP concentrations in the upper portion of the BAFs were as much as four times greater than the middle and lower portions of the dual media and 1.5 times greater in GAC. Sixteen CECs were spiked in the source water. At an EBCT of 18 min (min), GAC BAFs were highly effective with overall removals greater than 80% without pre-ozonation; exceptions included tri(2-chloroethyl) phosphate and iopromide. With a 10 min EBCT, the degree of CECs removal was reduced with less than half of the compounds removed at greater than 80%. The dual media BAFs showed limited CECs removal with only four compounds removed at greater than 80%, and 10 compounds were reduced by less than 50% with either EBCT. This study demonstrated that GAC BAFs with and without pre-ozonation are an effective and advanced technology for treating emerging contaminants. On the other hand, pre-ozonation is needed for dual media BAFs to remove CECs. The most cost effective operating conditions for dual media BAFs were a 10 min EBCT with the application of pre-ozonation. Copyright © 2017 Elsevier Ltd. All rights reserved.

Microbial succession in a compost-packed biofilter treating benzene-contaminated air.

PubMed

Borin, Sara; Marzorati, Massimo; Brusetti, Lorenzo; Zilli, Mario; Cherif, Hanene; Hassen, Abdennaceur; Converti, Attilio; Sorlini, Claudia; Daffonchio, Daniele

2006-03-01

Air artificially contaminated with increasing concentrations of benzene was treated in a laboratory scale compost-packed biofilter for 240 days with a removal efficiency of 81-100%. The bacterial community in the packing material (PM) at different heights of the biofilter was analysed every 60 days. Bacterial plate counts and ribosomal intergenic spacer analysis (RISA) of the isolated strains showed that the number of cultivable aerobic heterotrophic bacteria and the species diversity increased with benzene availability. Identification of the isolated species and the main bands in denaturing gradient gel electrophoresis (DGGE) profiles from total compost DNA during the treatment revealed that, at a relatively low volumetric benzene load (1.2< or =VBL< or =6.4 g m(-3) (PM) h(-1)), besides low G+C Gram positive bacteria, originally present in the packing compost, bacteroidetes and beta- and gamma-proteobacteria became detectable in the colonising population. At the VBL value (24.8 g m(-3) (PM) h(-1)) ensuring the maximum elimination capacity of the biofilter (20.1 g m(-3) (PM) h(-1)), strains affiliated to the genus Rhodococcus dominated the microflora, followed by beta-proteobacteria comprising the genera Bordetella and Neisseria. Under these conditions, more than 35% of the isolated strains were able to grow on benzene as the sole carbon source. Comparison of DGGE and automated RISA profiles of the total community and isolated strains showed that a complex bacterial succession occurred in the reactor in response to the increasing concentrations of the pollutant and that cultivable bacteria played a major role in benzene degradation under the adopted conditions.

Poisoned Playgrounds: Arsenic in "Pressure-Treated" Wood.

ERIC Educational Resources Information Center

Sharp, Renee; Walker, Bill

This study of 180 pressure-treated wood samples shows that treated wood is a much greater source of arsenic exposure for children than arsenic-contaminated drinking water. The report determines that an average 5-year-old, playing less than 2 weeks on a chromated-copper-arsenate-treated (CCA) wood play set would exceed the lifetime cancer risk…

Sources of Listeria monocytogenes Contamination in a Cold-Smoked Rainbow Trout Processing Plant Detected by Pulsed-Field Gel Electrophoresis Typing

PubMed Central

Autio, Tiina; Hielm, Sebastian; Miettinen, Maria; Sjöberg, Anna-Maija; Aarnisalo, Kaarina; Björkroth, Johanna; Mattila-Sandholm, Tiina; Korkeala, Hannu

1999-01-01

Sites of Listeria monocytogenes contamination in a cold-smoked rainbow trout (Oncorhynchus mykiss) processing plant were detected by sampling the production line, environment, and fish at different production stages. Two lots were monitored. The frequency of raw fish samples containing L. monocytogenes was low. During processing, the frequency of fish contaminated with L. monocytogenes clearly rose after brining, and the most contaminated sites of the processing plant were the brining and postbrining areas. A total of 303 isolates from the raw fish, product, and the environment were characterized by pulsed-field gel electrophoresis (PFGE). PFGE yielded nine pulsotypes, which formed four clusters. The predominating L. monocytogenes pulsotypes of the final product were associated with brining and slicing, whereas contaminants of raw fish were not detected in the final product. Air-mediated contamination in the plant could not be proved. In accordance with these results, an L. monocytogenes eradication program was planned. The use of hot steam, hot air, and hot water seemed to be useful in eliminating L. monocytogenes. None of the control samples taken in the 5 months after the eradication program was implemented contained L. monocytogenes. PMID:9872773

In situ removal of contamination from soil

DOEpatents

Lindgren, Eric R.; Brady, Patrick V.

1997-01-01

A process of remediation of cationic heavy metal contamination from soil utilizes gas phase manipulation to inhibit biodegradation of a chelating agent that is used in an electrokinesis process to remove the contamination, and further gas phase manipulation to stimulate biodegradation of the chelating agent after the contamination has been removed. The process ensures that the chelating agent is not attacked by bioorganisms in the soil prior to removal of the contamination, and that the chelating agent does not remain as a new contaminant after the process is completed.

Evaluating the efficacy of bioremediating a diesel-contaminated soil using ecotoxicological and bacterial community indices.

PubMed

Khudur, Leadin Salah; Shahsavari, Esmaeil; Miranda, Ana F; Morrison, Paul D; Nugegoda, Dayanthi; Ball, Andrew S

2015-10-01

Diesel represents a common environmental contaminant as a result of operation, storage, and transportation accidents. The bioremediation of diesel in a contaminated soil is seen as an environmentally safe approach to treat contaminated land. The effectiveness of the remediation process is usually assessed by the degradation of the total petroleum hydrocarbon (TPH) concentration, without considering ecotoxicological effects. The aim of this study was to assess the efficacy of two bioremediation strategies in terms of reduction in TPH concentration together with ecotoxicity indices and changes in the bacterial diversity assessed using PCR-denaturing gradient gel electrophoresis (DGGE). The biostimulation strategy resulted in a 90 % reduction in the TPH concentration versus 78 % reduction from the natural attenuation strategy over 12 weeks incubation in a laboratory mesocosm-containing diesel-contaminated soil. In contrast, the reduction in the ecotoxicity resulting from the natural attenuation treatment using the Microtox and earthworm toxicity assays was more than double the reduction resulting from the biostimulation treatment (45 and 20 % reduction, respectively). The biostimulated treatment involved the addition of nitrogen and phosphorus in order to stimulate the microorganisms by creating an optimal C:N:P molar ratio. An increased concentration of ammonium and phosphate was detected in the biostimulated soil compared with the naturally attenuated samples before and after the remediation process. Furthermore, through PCR-DGGE, significant changes in the bacterial community were observed as a consequence of adding the nutrients together with the diesel (biostimulation), resulting in the formation of distinctly different bacterial communities in the soil subjected to the two strategies used in this study. These findings indicate the suitability of both bioremediation approaches in treating hydrocarbon-contaminated soil, particularly biostimulation. Although

Process for treating alkaline wastes for vitrification

DOEpatents

Hsu, Chia-lin W.

1995-01-01

A process for treating alkaline wastes for vitrification. The process involves acidifying the wastes with an oxidizing agent such as nitric acid, then adding formic acid as a reducing agent, and then mixing with glass formers to produce a melter feed. The nitric acid contributes nitrates that act as an oxidant to balance the redox of the melter feed, prevent reduction of certain species to produce conducting metals, and lower the pH of the wastes to a suitable level for melter operation. The formic acid reduces mercury compounds to elemental mercury for removal by steam stripping, and MnO.sub.2 to the Mn(II) ion to prevent foaming of the glass melt. The optimum amounts of nitric acid and formic acid are determined in relation to the composition of the wastes, including the concentrations of mercury (II) and MnO.sub.2, noble metal compounds, nitrates, formates and so forth. The process minimizes the amount of hydrogen generated during treatment, while producing a redox-balanced feed for effective melter operation and a quality glass product.

Process for treating alkaline wastes for vitrification

DOEpatents

Hsu, C.L.W.

1995-07-25

A process is described for treating alkaline wastes for vitrification. The process involves acidifying the wastes with an oxidizing agent such as nitric acid, then adding formic acid as a reducing agent, and then mixing with glass formers to produce a melter feed. The nitric acid contributes nitrates that act as an oxidant to balance the redox of the melter feed, prevent reduction of certain species to produce conducting metals, and lower the pH of the wastes to a suitable level for melter operation. The formic acid reduces mercury compounds to elemental mercury for removal by steam stripping, and MnO{sub 2} to the Mn(II) ion to prevent foaming of the glass melt. The optimum amounts of nitric acid and formic acid are determined in relation to the composition of the wastes, including the concentrations of mercury (II) and MnO{sub 2}, noble metal compounds, nitrates, formates and so forth. The process minimizes the amount of hydrogen generated during treatment, while producing a redox-balanced feed for effective melter operation and a quality glass product. 4 figs.

Trace chemical contaminant generation rates for spacecraft contamination control system design

NASA Technical Reports Server (NTRS)

Perry, J. L.

1995-01-01

A spacecraft presents a unique design challenge with respect to providing a comfortable environment in which people can live and work. All aspects of the spacecraft environmental design including the size of the habitable volume, its temperature, relative humidity, and composition must be considered to ensure the comfort and health of the occupants. The crew members and the materials selected for outfitting the spacecraft play an integral part in designing a habitable spacecraft because material offgassing and human metabolism are the primary sources for continuous trace chemical contaminant generation onboard a spacecraft. Since these contamination sources cannot be completely eliminated, active control processes must be designed and deployed onboard the spacecraft to ensure an acceptably clean cabin atmosphere. Knowledge of the expected rates at which contaminants are generated is very important to the design of these processes. Data from past spacecraft missions and human contaminant production studies have been analyzed to provide this knowledge. The resulting compilation of contaminants and generation rates serve as a firm basis for past, present, and future contamination control system designs for space and aeronautics applications.

9 CFR 310.25 - Contamination with microorganisms; process control verification criteria and testing; pathogen...

Code of Federal Regulations, 2010 CFR

2010-01-01

... CERTIFICATION POST-MORTEM INSPECTION § 310.25 Contamination with microorganisms; process control verification... testing. (1) Each official establishment that slaughters livestock must test for Escherichia coli Biotype... poultry, shall test the type of livestock or poultry slaughtered in the greatest number. The establishment...

9 CFR 310.25 - Contamination with microorganisms; process control verification criteria and testing; pathogen...

Code of Federal Regulations, 2014 CFR

2014-01-01

... CERTIFICATION POST-MORTEM INSPECTION § 310.25 Contamination with microorganisms; process control verification... testing. (1) Each official establishment that slaughters livestock must test for Escherichia coli Biotype... poultry, shall test the type of livestock or poultry slaughtered in the greatest number. The establishment...

9 CFR 310.25 - Contamination with microorganisms; process control verification criteria and testing; pathogen...

Code of Federal Regulations, 2013 CFR

2013-01-01

... CERTIFICATION POST-MORTEM INSPECTION § 310.25 Contamination with microorganisms; process control verification... testing. (1) Each official establishment that slaughters livestock must test for Escherichia coli Biotype... poultry, shall test the type of livestock or poultry slaughtered in the greatest number. The establishment...

9 CFR 310.25 - Contamination with microorganisms; process control verification criteria and testing; pathogen...

Code of Federal Regulations, 2012 CFR

2012-01-01

... CERTIFICATION POST-MORTEM INSPECTION § 310.25 Contamination with microorganisms; process control verification... testing. (1) Each official establishment that slaughters livestock must test for Escherichia coli Biotype... poultry, shall test the type of livestock or poultry slaughtered in the greatest number. The establishment...

9 CFR 310.25 - Contamination with microorganisms; process control verification criteria and testing; pathogen...

Code of Federal Regulations, 2011 CFR

2011-01-01

... CERTIFICATION POST-MORTEM INSPECTION § 310.25 Contamination with microorganisms; process control verification... testing. (1) Each official establishment that slaughters livestock must test for Escherichia coli Biotype... poultry, shall test the type of livestock or poultry slaughtered in the greatest number. The establishment...

Removal of residual contaminants in petroleum-contaminated soil by Fenton-like oxidation.

PubMed

Lu, Mang; Zhang, Zhongzhi; Qiao, Wei; Guan, Yueming; Xiao, Meng; Peng, Chong

2010-07-15

The degradation of bioremediation residues by hydrogen peroxide in petroleum-contaminated soil was investigated at circumneutral pH using a Fenton-like reagent (ferric ion chelated with EDTA). Batch tests were done on 20 g soil suspended in 60 mL aqueous solution containing hydrogen peroxide and Fe(3+)-EDTA complex under constant stirring. A slurry reactor was used to treat the soil based on the optimal reactant conditions. Contaminants were characterized by Fourier transform infrared spectroscopy and Fourier transform ion cyclotron resonance mass spectrometry. The results showed that the optimal treatment condition was: the molar ratio of hydrogen peroxide to iron=200:1, and pH 7.0. Under the optimum condition, total dichloromethane-extractable organics were reduced from 14,800 to 2300 mg kg(-1) soil when the accumulative H(2)O(2) dosage was 2.45 mol kg(-1) soil during the reactor treatment. Abundance of viable cells was lower in incubated Fenton-like treated soil than in untreated soil. Oxidation of contaminants produced remarkable compositional and structural modifications. A fused ring compound, identified as C(34)H(38)N(1), was found to exhibit the greatest resistance to oxidation. 2010 Elsevier B.V. All rights reserved.

Insight into the prevalence and distribution of microbial contamination to evaluate water management in the fresh produce processing industry.

PubMed

Holvoet, Kevin; Jacxsens, Liesbeth; Sampers, Imca; Uyttendaele, Mieke

2012-04-01

This study provided insight into the degree of microbial contamination in the processing chain of prepacked (bagged) lettuce in two Belgian fresh-cut produce processing companies. The pathogens Salmonella and Listeria monocytogenes were not detected. Total psychrotrophic aerobic bacterial counts (TPACs) in water samples, fresh produce, and environmental samples suggested that the TPAC is not a good indicator of overall quality and best manufacturing practices during production and processing. Because of the high TPACs in the harvested lettuce crops, the process water becomes quickly contaminated, and subsequent TPACs do not change much throughout the production process of a batch. The hygiene indicator Escherichia coli was used to assess the water management practices in these two companies in relation to food safety. Practices such as insufficient cleaning and disinfection of washing baths, irregular refilling of the produce wash baths with water of good microbial quality, and the use of high product/water ratios resulted in a rapid increase in E. coli in the processing water, with potential transfer to the end product (fresh-cut lettuce). The washing step in the production of fresh-cut lettuce was identified as a potential pathway for dispersion of microorganisms and introduction of E. coli to the end product via cross-contamination. An intervention step to reduce microbial contamination is needed, particularly when no sanitizers are used as is the case in some European Union countries. Thus, from a food safety point of view proper water management (and its validation) is a critical point in the fresh-cut produce processing industry.

Remediation System Evaluation, Selma Pressure Treating Superfund Site

EPA Pesticide Factsheets

The Selma Pressure Treating site is located 15 miles south of Fresno, adjacent to the city limits of Selma,California and has subsurface contamination from a former wood treating facility. The site occupiesapproximately 40 acres, including...

CHEMICAL STABILIZATION OF MIXED ORGANIC AND METAL COMPOUNDS - EPA SITE PROGRAM DEMONSTRATION OF THE SILICATE TECHNOLOGY CORPORATION PROCESS

EPA Science Inventory

In November 1990, the Silicate Technology Corporation`s (STC) proprietary process for treating soil contaminated with toxic semivolatile organic and inorganic contaminants was evaluated in a Superfund Innovative Technology Evaluation (SITE) field demonstration at the Selma Pressu...

USE OF PLANT AND EARTHWORM BIOASSYS TO EVALUATE REMEDIATION OF SOIL FROM A SITE CONTAMINATED WITH POLYCHLORINATED BIPHENYLS

EPA Science Inventory

Soil from a site heavily contaminated with polychlorinated biphenyls (PCBs) was treated with a pilot-scale, solvent extraction tehnology. Bioassays in earthworms and plants were used to examine the efficacy of the remediation process for reducing the toxicity of the soil. The ear...

USE OF PLANT AND EARTHWORM BIOASSAYS TO EVALUATE REMEDIATION OF SOIL FROM A SITE CONTAMINATED WITH POLYCHLORINATED BIPHENYLS

EPA Science Inventory

Soil from a site heavily contaminated with polychlorinated biphenyls (PCBs) was treated with a pilot-scale, solvent extraction technology. Bioassays in earthworms and plants were used to examine the efficacy of the remediation process for reducing the toxicity of the soil. The ...

EPA Treatability Database Digs Deep for Data on Drinking Water Contaminants and Treatment Processes

EPA Science Inventory

The TDB is an interactive database that was initially developed in 2006-2007. The TDB currently contains more than 60 regulated and unregulated contaminants and 28 treatment processes that are known to be effective and are commonly employed at drinking water utilities. TDB lite...

SUPERFUND INNOVATIVE TECHNOLOGY EVALUATION PROGRAM Evaluation of Soil Amendment Technologies at the Crooksville/RosevillePottery Area of Concern Rocky Mountain Remediation ServicesEnvirobond™ Process

EPA Science Inventory

RMRS developed the Envirobond™ process to treat heavy metals in soil.This phosphate-based technology consists of a proprietary powder and solution that binds with metals in contaminated waste. RMRS claims that the Envirobond™ process converts metal contaminants from their leach...

Validation of Contamination Control in Rapid Transfer Port Chambers for Pharmaceutical Manufacturing Processes.

PubMed

Hu, Shih-Cheng; Shiue, Angus; Liu, Han-Yang; Chiu, Rong-Ben

2016-11-12

There is worldwide concern with regard to the adverse effects of drug usage. However, contaminants can gain entry into a drug manufacturing process stream from several sources such as personnel, poor facility design, incoming ventilation air, machinery and other equipment for production, etc. In this validation study, we aimed to determine the impact and evaluate the contamination control in the preparation areas of the rapid transfer port (RTP) chamber during the pharmaceutical manufacturing processes. The RTP chamber is normally tested for airflow velocity, particle counts, pressure decay of leakage, and sterility. The air flow balance of the RTP chamber is affected by the airflow quantity and the height above the platform. It is relatively easy to evaluate the RTP chamber's leakage by the pressure decay, where the system is charged with the air, closed, and the decay of pressure is measured by the time period. We conducted the determination of a vaporized H₂O₂ of a sufficient concentration to complete decontamination. The performance of the RTP chamber will improve safety and can be completely tested at an ISO Class 5 environment.

System of treating flue gas

DOEpatents

Ziegler, D.L.

1975-12-01

A system is described for treating or cleaning incinerator flue gas containing acid gases and radioactive and fissionable contaminants. Flue gas and a quench solution are fed into a venturi and then tangentially into the lower portion of a receptacle for restricting volumetric content of the solution. The upper portion of the receptacle contains a scrub bed to further treat or clean the flue gas.

Assessment of diesel-contaminated domestic wastewater treated by constructed wetlands for irrigation of chillies grown in a greenhouse.

PubMed

Al-Isawi, Rawaa H K; Scholz, Miklas; Al-Faraj, Furat A M

2016-12-01

In order to avoid environmental pollution and eliminate the need for using fertiliser, this study assessed for the first time the optimum performance of mature (in operation since 2011) vertical flow constructed wetlands in treating domestic wastewater (with and without hydrocarbon) and the subsequent recycling of the outflow to irrigate chillies (De Cayenne; Capsicum annuum (Linnaeus) Longum Group 'De Cayenne') grown in a greenhouse. Various variables were investigated to assess the treatment performance. Concerning chilli fruit numbers, findings showed that the highest fruit yields for all wetland filters were associated with those that received inflow wastewater with a high loading rate, reflecting the high nutrient availability in treated wastewater, which is of obvious importance for yield production. Findings also indicated that wetlands without hydrocarbon, small aggregate size, low contact time and low inflow loading rate provided high marketable yields (expressed in economic return). In comparison, chillies irrigated by filters with hydrocarbon contamination, small aggregate size, high contact time and high loading rate also resulted in high marketable yields of chillies, which pointed out the role of high contact time and high inflow load for better diesel degradation rates.

Surface analysis of 316 stainless steel treated with cold atmospheric plasma

NASA Astrophysics Data System (ADS)

Williams, David F.; Kellar, Ewen J. C.; Jesson, David A.; Watts, John F.

2017-05-01

The surface of 316 stainless steel has been modified using cold atmospheric plasma (CAP) to increase the surface free energy (by cleaning the and chemically activating the surface)IN preparation for subsequent processes such as painting, coating or adhesive bonding. The analyses carried out, on CAP treated 316 stainless steel surfaces, includes X-ray photoelectron spectroscopy (XPS), imaging XPS (iXPS), and surface free energy (SFE) analysis using contact angle measurements. The CAP treatment is shown to increase the SFE of as-received 316 stainless steel from ∼39 mJ m-1 to >72 mJ m-1 after a short exposure to the plasma torch. This was found to correlate to a reduction in adventitious carbon, as determined by XPS analysis of the surface. The reduction from ∼90 at% to ∼30% and ∼39 at%, after being plasma treated for 5 min and 15 s respectively, shows that the process is relatively quick at changing the surface. It is suggested that the mechanism that causes the increase in surface free energy is chain scission of the hydrocarbon contamination triggered by free electrons in the plasma plume followed by chemical functionalisation of the metal oxide surface and some of the remaining carbon contamination layer.

Factors affecting sodium hypochlorite extraction of CCA from treated wood.

PubMed

Gezer, E D; Cooper, P A

2009-12-01

Significant amounts of chromated copper arsenate (CCA) treated wood products, such as utility poles and residential construction wood, remain in service. There is increasing public concern about environmental contamination from CCA-treated wood when it is removed from service for reuse or recycling, placed in landfills or burned in commercial incinerators. In this paper, we investigated the effects of time, temperature and sodium hypochlorite concentration on chromium oxidation and extraction of chromated copper arsenate from CCA-treated wood (Type C) removed from service. Of the conditions evaluated, reaction of milled wood with sodium hypochlorite for one hour at room temperature followed by heating at 75 degrees C for two hours gave the highest extraction efficiency. An average of 95% Cr, 99% Cu and 96% As could be removed from CCA-treated, milled wood by this process. Most of the extracted chromium was oxidized to the hexavalent state and could therefore be recycled in a CCA treating solution. Sodium hypochlorite extracting solutions could be reused several times to extract CCA components from additional treated wood samples.

Bioswales reduce contaminants associated with toxicity in urban storm water.

PubMed

Anderson, Brian S; Phillips, Bryn M; Voorhees, Jennifer P; Siegler, Katie; Tjeerdema, Ronald

2016-12-01

Contamination and toxicity associated with urban storm water runoff are a growing concern because of the potential impacts on receiving systems. California water regulators are mandating implementation of green infrastructure as part of new urban development projects to treat storm water and increase infiltration. Parking lot bioswales are low impact development practices that promote filtering of runoff through plants and soil. Studies have demonstrated that bioswales reduce concentrations of suspended sediments, metals, and hydrocarbons. There have been no published studies evaluating how well these structures treat current-use pesticides, and studies have largely ignored whether bioswales reduce toxicity in surface water. Three storms were monitored at 3 commercial and residential sites, and reductions of contaminants and associated toxicity were quantified. Toxicity testing showed that the majority of untreated storm water samples were toxic to amphipods (Hyalella azteca) and midges (Chironomus dilutus), and toxicity was reduced by the bioswales. No samples were toxic to daphnids (Ceriodaphnia dubia) or fish (Pimephales promelas). Contaminants were significantly reduced by the bioswales, including suspended solids (81% reduction), metals (81% reduction), hydrocarbons (82% reduction), and pyrethroid pesticides (74% reduction). The single exception was the phenypyrazole pesticide fipronil, which showed inconsistent treatment. The results demonstrate these systems effectively treat contaminated storm water associated with surface water toxicity but suggest that modifications of their construction may be required to treat some contaminant classes. Environ Toxicol Chem 2016;35:3124-3134. © 2016 SETAC. © 2016 SETAC.

Fluorescence Imaging Reveals Surface Contamination

NASA Technical Reports Server (NTRS)

Schirato, Richard; Polichar, Raulf

1992-01-01

In technique to detect surface contamination, object inspected illuminated by ultraviolet light to make contaminants fluoresce; low-light-level video camera views fluorescence. Image-processing techniques quantify distribution of contaminants. If fluorescence of material expected to contaminate surface is not intense, tagged with low concentration of dye.

Oxidation of contaminative methane traces with radio-frequency discharge

NASA Technical Reports Server (NTRS)

Flamm, D. L.; Wydeven, T. L.

1976-01-01

An 11.8 MHz glow discharge was used to oxidize trace levels of methane in oxygen. The concentration of methane can be reduced by three orders of magnitude. The effects of power (0-400 W), flow rate (10-1000 cc-STP/min) and concentration (70-8000 ppm) were investigated at pressures ranging from 50 torr to almost 1 atm. No organic reaction products were detected in the treated gas stream. The process may prove useful for the removal of atmospheric trace contaminants at ambient pressure.

Simulating Mass Removal of Groundwater Contaminant Plumes with Complex and Simple Models

NASA Astrophysics Data System (ADS)

Lopez, J.; Guo, Z.; Fogg, G. E.

2016-12-01

Chlorinated solvents used in industrial, commercial, and other applications continue to pose significant threats to human health through contamination of groundwater resources. A recent National Research Council report concludes that it is unlikely that remediation of these complex sites will be achieved in a time frame of 50-100 years under current methods and standards (NRC, 2013). Pump and treat has been a common strategy at many sites to contain and treat groundwater contamination. In these sites, extensive retention of contaminant mass in low-permeability materials (tailing) has been observed after years or decades of pumping. Although transport models can be built that contain enough of the complex, 3D heterogeneity to simulate the tailing and long cleanup times, this is seldom done because of the large data and computational burdens. Hence, useful, reliable models to simulate various cleanup strategies are rare. The purpose of this study is to explore other potential ways to simulate the mass-removal processes with shorter time and less cost but still produce robust results by capturing effects of the heterogeneity and long-term retention of mass. A site containing a trichloroethylene groundwater plume was selected as the study area. The plume is located within alluvial sediments in the Tucson Basin. A fully heterogeneous domain is generated first and MODFLOW is used to simulate the flow field. Contaminant transport is simulated using both MT3D and RWHet for the fully heterogeneous model. Other approaches, including dual-domain mass transfer and heterogeneous chemical reactions, are manipulated to simulate the mass removal in a less heterogeneous, or homogeneous, domain and results are compared to the results obtained from complex models. The capability of these simpler models to simulate remediation processes, especially capture the late-time tailing, are examined.

New wash aid T-128 improves efficacy of chlorine against cross contamination by bacterial pathogens in fresh-cut lettuce processing

USDA-ARS?s Scientific Manuscript database

Chlorinated water is widely used as the primary anti-microbial intervention during fresh-cut produce processing. Free chlorine in chlorinated water can provide effective reduction of potential contaminations by microbial pathogens, and, more importantly, effectively prevent cross contamination of p...

Nontoxic chemical process for in situ permeability enhancement and accelerated decontamination of fine-grain subsurface sediments

DOEpatents

Kansa, E.J.; Wijesinghe, A.M.; Viani, B.E.

1997-01-14

The remediation of heterogeneous subsurfaces is extremely time consuming and expensive with current and developing technologies. Although such technologies can adequately remove contaminants in the high hydraulic conductivity, coarse-grained sediments, they cannot access the contaminated low hydraulic conductivity fine-grained sediments. The slow bleed of contaminants from the fine-grained sediments is the primary reason why subsurface remediation is so time-consuming and expensive. This invention addresses the problem of remediating contaminated fine-grained sediments. It is intended that, in the future, a heterogeneous site be treated by a hybrid process that first remediates the high hydraulic conductivity, coarse-grained sediments, to be followed by the process, described in this invention, to treat the contaminated low hydraulic conductivity fine-grained sediments. The invention uses cationic flocculants and organic solvents to collapse the swelling negative double layer surrounding water saturated clay particles, causing a flocculated, cracked clay structure. The modification of the clay fabric in fine-grained sediments dramatically increases the hydraulic conductivity of previously very tight clays many orders of magnitude. 8 figs.

Nontoxic chemical process for in situ permeability enhancement and accelerated decontamination of fine-grain subsurface sediments

DOEpatents

Kansa, Edward J.; Wijesinghe, Ananda M.; Viani, Brian E.

1997-01-01

The remediation of heterogeneous subsurfaces is extremely time consuming and expensive with current and developing technologies. Although such technologies can adequately remove contaminants in the high hydraulic conductivity, coarse-grained sediments, they cannot access the contaminated low hydraulic conductivity fine-grained sediments. The slow bleed of contaminants from the fine-grained sediments is the primary reason why subsurface remediation is so time-consuming and expensive. This invention addresses the problem of remediating contaminated fine-grained sediments. It is intended that, in the future, a heterogeneous site be treated by a hybrid process that first remediates the high hydraulic conductivity, coarse-grained sediments, to be followed by the process, described in this invention, to treat the contaminated low hydraulic conductivity fine-grained sediments. The invention uses cationic flocculents and organic solvents to collapse the swelling negative double layer surrounding water saturated clay particles, causing a flocculated, cracked clay structure. The modification of the clay fabric in fine-grained sediments dramatically increases the hydraulic conductivity of previously very tight clays many orders of magnitude.

Campylobacter in Broiler Chicken and Broiler Meat in Sri Lanka: Influence of Semi-Automated vs. Wet Market Processing on Campylobacter Contamination of Broiler Neck Skin Samples.

PubMed

Kottawatta, Kottawattage S A; Van Bergen, Marcel A P; Abeynayake, Preeni; Wagenaar, Jaap A; Veldman, Kees T; Kalupahana, Ruwani S

2017-11-29

Broiler meat can become contaminated with Campylobacter of intestinal origin during processing. The present study aimed to identify the prevalence of Campylobacter in broiler flocks and meat contamination at retail shops, and determine the influence of semi-automated and wet market processing on Campylobacter contamination of neck skin samples. Samples were collected from semi-automated plants ( n = 102) and wet markets ( n = 25). From each batch of broilers, pooled caecal samples and neck skin samples were tested for Campylobacter . Broiler meat purchased from retail outlets ( n = 37) was also tested. The prevalence of Campylobacter colonized broiler flocks was 67%. The contamination of meat at retail was 59%. Both semi-automated and wet market processing resulted to contaminate the broiler neck skins to the levels of 27.4% and 48%, respectively. When Campylobacter -free broiler flocks were processed in semi-automated facilities 15% (5/33) of neck skin samples became contaminated by the end of processing whereas 25% (2/8) became contaminated after wet market processing. Characterization of isolates revealed a higher proportion of C. coli compared to C. jejuni . Higher proportions of isolates were resistant to important antimicrobials. This study shows the importance of Campylobacter in poultry industry in Sri Lanka and the need for controlling antimicrobial resistance.

Campylobacter in Broiler Chicken and Broiler Meat in Sri Lanka: Influence of Semi-Automated vs. Wet Market Processing on Campylobacter Contamination of Broiler Neck Skin Samples

PubMed Central

Kottawatta, Kottawattage S. A.; Van Bergen, Marcel A. P.; Abeynayake, Preeni; Wagenaar, Jaap A.; Veldman, Kees T.; Kalupahana, Ruwani S.

2017-01-01

Broiler meat can become contaminated with Campylobacter of intestinal origin during processing. The present study aimed to identify the prevalence of Campylobacter in broiler flocks and meat contamination at retail shops, and determine the influence of semi-automated and wet market processing on Campylobacter contamination of neck skin samples. Samples were collected from semi-automated plants (n = 102) and wet markets (n = 25). From each batch of broilers, pooled caecal samples and neck skin samples were tested for Campylobacter. Broiler meat purchased from retail outlets (n = 37) was also tested. The prevalence of Campylobacter colonized broiler flocks was 67%. The contamination of meat at retail was 59%. Both semi-automated and wet market processing resulted to contaminate the broiler neck skins to the levels of 27.4% and 48%, respectively. When Campylobacter-free broiler flocks were processed in semi-automated facilities 15% (5/33) of neck skin samples became contaminated by the end of processing whereas 25% (2/8) became contaminated after wet market processing. Characterization of isolates revealed a higher proportion of C. coli compared to C. jejuni. Higher proportions of isolates were resistant to important antimicrobials. This study shows the importance of Campylobacter in poultry industry in Sri Lanka and the need for controlling antimicrobial resistance. PMID:29186018

Effects of electrolyzed oxidizing water on reducing Listeria monocytogenes contamination on seafood processing surfaces.

PubMed

Liu, Chengchu; Duan, Jingyun; Su, Yi-Cheng

2006-02-15

The effects of electrolyzed oxidizing (EO) water on reducing Listeria monocytogenes contamination on seafood processing surfaces were studied. Chips (5 x 5 cm(2)) of stainless steel sheet (SS), ceramic tile (CT), and floor tile (FT) with and without crabmeat residue on the surface were inoculated with L. monocytogenes and soaked in tap or EO water for 5 min. Viable cells of L. monocytogenes were detected on all chip surfaces with or without crabmeat residue after being held at room temperature for 1 h. Soaking contaminated chips in tap water resulted in small-degree reductions of the organism (0.40-0.66 log cfu/chip on clean surfaces and 0.78-1.33 log cfu/chip on dirty surfaces). Treatments of EO water significantly (p<0.05) reduced L. monocytogenes on clean surfaces (3.73 log on SS, 4.24 log on CT, and 5.12 log on FT). Presence of crabmeat residue on chip surfaces reduced the effectiveness of EO water on inactivating Listeria cells. However, treatments of EO water also resulted in significant reductions of L. monocytogenes on dirty surfaces (2.33 log on SS and CT and 1.52 log on FT) when compared with tap water treatments. The antimicrobial activity of EO water was positively correlated with its chlorine content. High oxidation-reduction potential (ORP) of EO water also contributed significantly to its antimicrobial activity against L. monocytogenes. EO water was more effective than chlorine water on inactivating L. monocytogenes on surfaces and could be used as a chlorine alternative for sanitation purpose. Application of EO water following a thorough cleaning process could greatly reduce L. monocytogenes contamination in seafood processing environments.

Assessing the Impact of Source-Zone Remediation Efforts at the Contaminant-Plume Scale Through Analysis of Contaminant Mass Discharge

PubMed Central

Brusseau, M. L.; Hatton, J.; DiGuiseppi, W.

2011-01-01

The long-term impact of source-zone remediation efforts was assessed for a large site contaminated by trichloroethene. The impact of the remediation efforts (soil vapor extraction and in-situ chemical oxidation) was assessed through analysis of plume-scale contaminant mass discharge, which was measured using a high-resolution data set obtained from 23 years of operation of a large pump-and-treat system. The initial contaminant mass discharge peaked at approximately 7 kg/d, and then declined to approximately 2 kg/d. This latter value was sustained for several years prior to the initiation of source-zone remediation efforts. The contaminant mass discharge in 2010, measured several years after completion of the two source-zone remediation actions, was approximately 0.2 kg/d, which is ten times lower than the value prior to source-zone remediation. The time-continuous contaminant mass discharge data can be used to evaluate the impact of the source-zone remediation efforts on reducing the time required to operate the pump-and-treat system, and to estimate the cost savings associated with the decreased operational period. While significant reductions have been achieved, it is evident that the remediation efforts have not completely eliminated contaminant mass discharge and associated risk. Remaining contaminant mass contributing to the current mass discharge is hypothesized to comprise poorly-accessible mass in the source zones, as well as aqueous (and sorbed) mass present in the extensive lower-permeability units located within and adjacent to the contaminant plume. The fate of these sources is an issue of critical import to the remediation of chlorinated-solvent contaminated sites, and development of methods to address these sources will be required to achieve successful long-term management of such sites and to ultimately transition them to closure. PMID:22115080

[Study on rapid analysis method of pesticide contamination in processed foods by GC-MS and GC-FPD].

PubMed

Kobayashi, Maki; Otsuka, Kenji; Tamura, Yasuhiro; Tomizawa, Sanae; Kamijo, Kyoko; Iwakoshi, Keiko; Sato, Chizuko; Nagayama, Toshihiro; Takano, Ichiro

2011-01-01

A simple and rapid method using GC-MS and GC-FPD for the determination of pesticide contamination in processed food has been developed. Pesticides were extracted from a sample with ethyl acetate in the presence of anhydrous sodium sulfate, then cleaned up with a combination of mini-columns, such as macroporous diatomaceous earth, C18, GCB (graphite carbon black) and PSA. Recovery tests of 57 pesticides (known to be toxic or harmful) from ten kinds of processed foods (butter, cheese, corned beef, dried shrimp, frozen Chinese dumplings, grilled eels, instant noodles, kimchi, retort-packed curry and wine) were performed, and the recovery rates were mostly between 70% and 120%. This method can be used to judge whether or not processed foods are contaminated with pesticides at potentially harmful levels.

Investigation of the effect of contaminations and cleaning processes on the surface properties of brazing surfaces

NASA Astrophysics Data System (ADS)

Bobzin, K.; Öte, M.; Wiesner, S.

2017-03-01

The quality of brazed joints is determined by different factors such as the atmosphere and the parameters during brazing as well as the condition of the brazing surfaces. Residues of lubricants used during machining of the components and the subsequent cleaning processes can contaminate the faying surfaces and can hence influence the flow ability of the molten filler metals. Besides their influence on the filler metal flow, the residues can result in the formation of carbonic phases in the joint leading to a possible reduction of the corrosion resistance and the mechanical properties. The first step of the current study with the aim of avoiding these defects is to identify the influence of critical contaminations and cleaning methods on the quality of the brazed joints. In a first step, contaminations on AISI304 and Inconel alloy 625 due to different cooling lubricants and the effect of several cleaning methods, in particular plasma cleaning, have been investigated. Information about the surface energy of contaminated and cleaned surfaces was gained by measuring contact angle of testing fluids. Additionally, the lubricants and the resulting contamination products have been analyzed considering the influence of a heat treatment.

Exposure assessment and process sensitivity analysis of the contamination of Campylobacter in poultry products.

PubMed

Osiriphun, S; Iamtaweejaloen, P; Kooprasertying, P; Koetsinchai, W; Tuitemwong, K; Erickson, L E; Tuitemwong, P

2011-07-01

Studies were conducted in a Thai poultry plant to identify the factors that affected numbers of Campylobacter jejuni in chicken carcasses. The concentrations of Campylobacter were determined using the SimPlate most probable number and modified charcoal cefoperazone deoxycholate plating methods. Results indicated that the mean concentrations of C. jejuni in carcasses after scalding, plucking, and chilling were 2.93 ± 0.31, 2.98 ± 0.38, 2.88 ± 0.31, and 0.85 ± 0.95 log cfu, whereas the concentrations of C. jejuni in the scalding tank water, plucked feathers, and chicken breast portion were 1.39 ± 0.70, 3.28 ± 0.52, and 0.50 ± 1.22 log cfu, respectively. Sensitivity analysis using tornado order correlation analysis showed that risk parameters affecting the contamination of C. jejuni in the chicken slaughter and processing plant could be ranked as chilling water pH, number of pathogens in the scald tank water, scalding water temperature, number of C. jejuni on plucked feathers, and residual chlorine in the chill water, respectively. The exposure assessment and analysis of process parameters indicated that some of the current critical control points were not effective. The suggested interventions included preventing fecal contamination during transportation; increasing the scalding temperature, giving the scalding water a higher countercurrent flow rate; reducing contamination of feathers in the scalding tank to decrease C. jejuni in the scalding water; spraying water to reduce contamination at the plucking step; monitoring and maintaining the chill water pH at 6.0 to 6.5; and increasing the residual chlorine in the chill water. These interventions were recommended for inclusion in the hazard analysis and critical control point plan of the plant.

An Assessment of the International Space Station's Trace Contaminant Control Subassembly Process Economics

NASA Technical Reports Server (NTRS)

Perry J. L.; Cole, H. E.; El-Lessy, H. N.

2005-01-01

The International Space Station (ISS) Environmental Control and Life Support System includes equipment speci.cally designed to actively remove trace chemical contamination from the cabin atmosphere. In the U.S. on-orbit segment, this function is provided by the trace contaminant control subassembly (TCCS) located in the atmosphere revitalization subsystem rack housed in the laboratory module, Destiny. The TCCS employs expendable adsorbent beds to accomplish its function leading to a potentially signi.cant life cycle cost over the life of the ISS. Because maintaining the TCCSs proper can be logistically intensive, its performance in .ight has been studied in detail to determine where savings may be achieved. Details of these studies and recommendations for improving the TCCS s process economics without compromising its performance or crew health and safety are presented and discussed.

Techniques for the stabilization and assessment of treated copper-, chromium-, and arsenic-contaminated soil.

PubMed

Maurice, Christian; Lidelöw, Sofia; Gustavsson, Björn; Lättström, Anders; Ragnvaldsson, Daniel; Leffler, Per; Lövgren, Lars; Tesfalidet, Solomon; Kumpiene, Jurate

2007-09-01

Remediation mainly based on excavation and burial of the contaminated soil is impractical with regard to the large numbers of sites identified as being in need of remediation. Therefore, alternative methods are needed for brownfield remediation. This study was conducted to assess a chemical stabilization procedure of CCA-contaminated soil using iron (Fe)-containing blaster sand (BS) or oxygen-scarfing granulate (OSG). The stabilization technique was assessed with regard to the feasibility of mixing ameliorants at an industrial scale and the efficiency of the stabilization under different redox conditions. The stability was investigated under natural conditions in 1-m3 lysimeters in a field experiment, and the effect of redox conditions was assessed in a laboratory experiment (10 L). The treatments with high additions of ameliorant (8% and 17%) were more successful in both the laboratory and field experiments, even though there was enough Fe on a stochiometric basis even at the lowest addition rates (0.1% and 1%). The particle size of the Fe and the mixing influenced the stabilization efficiency. The development of anaerobic conditions, simulated by water saturation, increases the fraction of arsenic (AsIII) and, consequently, As mobility. The use of high concentrations of OSG under aerobic conditions increased the concentrations of nickel (Ni) and copper (Cu) in the pore water. However, under anaerobic conditions, it decreased the As leaching compared with the untreated soil, and Ni and Cu leaching was not critical. The final destination of the treated soil should govern the amendment choice, that is, an OSG concentration of approximately 10% may be suitable if the soil is to be landfilled under anaerobic conditions. Alternatively, the soil mixed with 1% BS could be kept under aerobic conditions in a landfill cover or in situ at a brownfield site. In addition, the treatment with BS appeared to produce better effects in the long term than treatment with OSG.

Influence assessment of a lab-scale ripening process on the quality of mechanically-biologically treated MSW for possible recovery.

PubMed

Di Lonardo, Maria Chiara; Binner, Erwin; Lombardi, Francesco

2015-09-01

In this study, the influence of an additional ripening process on the quality of mechanically-biologically treated MSW was evaluated in the prospective of recovering the end material, rather than landfilling. The biostabilised waste (BSW) coming from one of the MBT plants of Rome was therefore subjected to a ripening process in slightly aerated lab test cells. An in-depth investigation on the biological reactivity was performed by means of different types of tests (aerobic and anaerobic biological tests, as well as FT-IR spectroscopy method). A physical-chemical characterisation of waste samples progressively taken during the ripening phase was carried out, as well. In addition, the ripened BSW quality was assessed by comparing the characteristics of a compost sampled at the composting plant of Rome which treat source segregated organic wastes. Results showed that the additional ripening process allowed to obtain a better quality of the biostabilised waste, by achieving a much higher biological stability compared to BSW as-received and similar to that of the tested compost. An important finding was the lower heavy metals (Co, Cr, Cu, Ni, Pb and Zn) release in water phase at the end of the ripening compared to the as-received BSW, showing that metals were mainly bound to solid organic matter. As a result, the ripened waste, though not usable in agriculture as found for the compost sample, proved anyhow to be potentially suitable for land reclamation purposes, such as in landfills as cover material or mixed with degraded and contaminated soil for organic matter and nutrients supply and for metals recovery, respectively. In conclusion the study highlights the need to extend and optimise the biological treatment in the MBT facilities and opens the possibility to recover the output waste instead of landfilling. Copyright © 2015 Elsevier Ltd. All rights reserved.

Good Manufacturing Practices and Microbial Contamination Sources in Orange Fleshed Sweet Potato Puree Processing Plant in Kenya

PubMed Central

Abong', George Ooko

2018-01-01

Limited information exists on the status of hygiene and probable sources of microbial contamination in Orange Fleshed Sweet Potato (OFSP) puree processing. The current study is aimed at determining the level of compliance to Good Manufacturing Practices (GMPs), hygiene, and microbial quality in OFSP puree processing plant in Kenya. Intensive observation and interviews using a structured GMPs checklist, environmental sampling, and microbial analysis by standard microbiological methods were used in data collection. The results indicated low level of compliance to GMPs with an overall compliance score of 58%. Microbial counts on food equipment surfaces, installations, and personnel hands and in packaged OFSP puree were above the recommended microbial safety and quality legal limits. Steaming significantly (P < 0.05) reduced microbial load in OFSP cooked roots but the counts significantly (P < 0.05) increased in the puree due to postprocessing contamination. Total counts, yeasts and molds, Enterobacteriaceae, total coliforms, and E. coli and S. aureus counts in OFSP puree were 8.0, 4.0, 6.6, 5.8, 4.8, and 5.9 log10 cfu/g, respectively. In conclusion, equipment surfaces, personnel hands, and processing water were major sources of contamination in OFSP puree processing and handling. Plant hygiene inspection, environmental monitoring, and food safety trainings are recommended to improve hygiene, microbial quality, and safety of OFSP puree. PMID:29808161

Good Manufacturing Practices and Microbial Contamination Sources in Orange Fleshed Sweet Potato Puree Processing Plant in Kenya.

PubMed

Malavi, Derick Nyabera; Muzhingi, Tawanda; Abong', George Ooko

2018-01-01

Limited information exists on the status of hygiene and probable sources of microbial contamination in Orange Fleshed Sweet Potato (OFSP) puree processing. The current study is aimed at determining the level of compliance to Good Manufacturing Practices (GMPs), hygiene, and microbial quality in OFSP puree processing plant in Kenya. Intensive observation and interviews using a structured GMPs checklist, environmental sampling, and microbial analysis by standard microbiological methods were used in data collection. The results indicated low level of compliance to GMPs with an overall compliance score of 58%. Microbial counts on food equipment surfaces, installations, and personnel hands and in packaged OFSP puree were above the recommended microbial safety and quality legal limits. Steaming significantly ( P < 0.05) reduced microbial load in OFSP cooked roots but the counts significantly ( P < 0.05) increased in the puree due to postprocessing contamination. Total counts, yeasts and molds, Enterobacteriaceae, total coliforms, and E. coli and S. aureus counts in OFSP puree were 8.0, 4.0, 6.6, 5.8, 4.8, and 5.9 log 10 cfu/g, respectively. In conclusion, equipment surfaces, personnel hands, and processing water were major sources of contamination in OFSP puree processing and handling. Plant hygiene inspection, environmental monitoring, and food safety trainings are recommended to improve hygiene, microbial quality, and safety of OFSP puree.

EPA SITE DEMONSTRATION OF THE BIOTROL SOIL WASHING PROCESS

EPA Science Inventory

A pilot-scale soil washing process, patented by BioTrol, Inc., was demonstrate on soil contaminated by wood treating waste, primarily pentachlorophenol (PCP) and creosote-derived polynuclear aromatic hydrocarbons (PAHs). Although soil washing was the main object of this demonstra...

Contribution of treated wastewater to the microbiological quality of Seine River in Paris.

PubMed

Moulin, Laurent; Richard, Fanny; Stefania, Sabrina; Goulet, Marion; Gosselin, Sylvie; Gonçalves, Alexandre; Rocher, Vincent; Paffoni, Catherine; Dumètre, Aurélien

2010-10-01

Urban part of Seine River serving as drinking water supply in Paris can be heavily contaminated by Cryptosporidium spp. and Giardia duodenalis. In the absence of agricultural practice in this highly urbanized area, we investigated herein the contribution of treated wastewater to the microbiological quality of this river focusing on these two parasites. Other microorganisms such as faecal bacterial indicators, enteroviruses and oocysts of Toxoplasma gondii were assessed concurrently. Raw wastewaters were heavily contaminated by Cryptosporidium and Giardia (oo)cysts, whereas concentrations of both protozoa in treated wastewater were lower. Treated wastewater, flowed into Seine River, had a parasite concentration closed to the one found along the river, in particular at the entry of a drinking water plant (DWP). Even if faecal bacteria were reliable indicators of a reduction in parasite concentrations during the wastewater treatment, they were not correlated to protozoal contamination of wastewater and river water. Oocysts of T. gondii were not found in both raw and treated wastewater, or in Seine River. Parasitic contamination was shown to be constant in the Seine River up to 40 km upstream Paris. Altogether, these results strongly suggest that treated wastewater does not contribute to the main parasitic contamination of the Seine River usually observed in this urbanized area. Copyright © 2010 Elsevier Ltd. All rights reserved.

Process for treating ab5 nickel-metal hydride battery scrap

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

Lyman, J.W.; Palmer, G.R.

1994-12-31

A process for treating an AB5 Ni-MH battery to recover purified positive and negative electrode components of the battery is disclosed. An AB5 Ni-MH battery is placed in a mineral acid leach solution to cause the positive and negative electrode components of the battery to separate.

27 CFR 24.250 - Application for use of new treating material or process.

Code of Federal Regulations, 2010 CFR

2010-04-01

... of tests of the shelf life of the treated wine; (6) A tabulation of pertinent information derived... TOBACCO TAX AND TRADE BUREAU, DEPARTMENT OF THE TREASURY LIQUORS WINE Storage, Treatment and Finishing of Wine § 24.250 Application for use of new treating material or process. (a) General. If the proprietor...

Validation of Contamination Control in Rapid Transfer Port Chambers for Pharmaceutical Manufacturing Processes

PubMed Central

Hu, Shih-Cheng; Shiue, Angus; Liu, Han-Yang; Chiu, Rong-Ben

2016-01-01

There is worldwide concern with regard to the adverse effects of drug usage. However, contaminants can gain entry into a drug manufacturing process stream from several sources such as personnel, poor facility design, incoming ventilation air, machinery and other equipment for production, etc. In this validation study, we aimed to determine the impact and evaluate the contamination control in the preparation areas of the rapid transfer port (RTP) chamber during the pharmaceutical manufacturing processes. The RTP chamber is normally tested for airflow velocity, particle counts, pressure decay of leakage, and sterility. The air flow balance of the RTP chamber is affected by the airflow quantity and the height above the platform. It is relatively easy to evaluate the RTP chamber′s leakage by the pressure decay, where the system is charged with the air, closed, and the decay of pressure is measured by the time period. We conducted the determination of a vaporized H2O2 of a sufficient concentration to complete decontamination. The performance of the RTP chamber will improve safety and can be completely tested at an ISO Class 5 environment. PMID:27845748

A combined process coupling phytoremediation and in situ flushing for removal of arsenic in contaminated soil.

PubMed

Yan, Xiulan; Liu, Qiuxin; Wang, Jianyi; Liao, Xiaoyong

2017-07-01

Phytoremediation and soil washing are both potentially useful for remediating arsenic (As)-contaminated soils. We evaluated the effectiveness of a combined process coupling phytoremediation and in situ soil flushing for removal of As in contaminated soil through a pilot study. The results showed that growing Pteris vittata L. (P.v.) accompanied by soil flushing of phosphate (P.v./Flushing treatment) could significantly decrease the total As concentration of soil over a 37day flushing period compared with the single flushing (Flushing treatment). The P.v./Flushing treatment removed 54.04% of soil As from contaminated soil compared to 47.16% in Flushing treatment, suggesting that the growth of P. vittata was beneficial for promoting the removal efficiency. We analyzed the As fractionation in soil and As concentration in soil solution to reveal the mechanism behind this combined process. Results showed that comparing with the control treatment, the percent of labile arsenate fraction significantly increased by 17% under P.v./Flushing treatment. As concentration in soil solution remained a high lever during the middle and later periods (51.26-56.22mg/L), which was significantly higher than the Flushing treatment. Although soil flushing of phosphate for more than a month, P. vittata still had good accumulation and transfer capacity of As of the soil. The results of the research revealed that combination of phytoremediation and in situ soil flushing is available to remediate As-contaminated soils. Copyright © 2016. Published by Elsevier B.V.

Growth determinations for unattached bacteria in a contaminated aquifer.

USGS Publications Warehouse

Harvey, R.W.; George, L.H.

1987-01-01

Growth rates of unattached bacteria in groundwater contaminated with treated sewage and collected at various distances from the source of contamination were estimated by using frequency of dividing cells and tritiated-thymidine uptake and compared with growth rates obtained with unsupplemented, closed-bottle incubations. Estimates of bacterial generation times [(In 2)/mu] along a 3-km-long transect in oxygen-depleted (0.1 to 0.7 mg of dissolved oxygen liter-1) groundwater ranged from 16 h at 0.26 km downgradient from an on-land, treated-sewage outfall to 139 h at 1.6 km and correlated with bacterial abundance (r2 = 0.88 at P less than 0.001). Partitioning of assimilated thymidine into nucleic acid generally decreased with distance from the contaminant source, and one population in heavily contaminated groundwater assimilated little thymidine during a 20-h incubation. Several assumptions commonly made when frequency of dividing cells and tritiated-thymidine uptake are used were not applicable to the groundwater samples.

Recharge processes drive sulfate reduction in an alluvial aquifer contaminated with landfill leachate

USGS Publications Warehouse

Scholl, M.A.; Cozzarelli, I.M.; Christenson, S.C.

2006-01-01

present in the root zone, and SO42- reduction may be coupled to methane oxidation. The results show that sulfur (and possibly nitrogen) redox processes within the top 2??m of the aquifer are directly related to recharge timing and seasonal water level changes in the aquifer. The results suggest that SO42- reduction associated with the infiltration of recharge may be a significant factor affecting natural attenuation of contaminants in alluvial aquifers. ?? 2006 Elsevier B.V. All rights reserved.

Impact of Scale-Dependent Coupled Processes on Solute Fate and Transport in the Critical Zone: Case Studies Involving Inorganic and Radioactive Contaminants

NASA Astrophysics Data System (ADS)

Jardine, P. M.; Gentry, R. W.

2011-12-01

Soil, the thin veneer of matter covering the Earths surface that supports a web of living diversity, is often abused through anthropogenic inputs of toxic waste. This subsurface regime, coupled with life sustaining surface water and groundwater is known as the "Critical Zone". The disposal of radioactive and toxic organic and inorganic waste generated by industry and various government agencies has historically involved shallow land burial or the use of surface impoundments in unsaturated soils and sediments. Presently, contaminated sites have been closing rapidly and many remediation strategies have chosen to leave contaminants in-place. As such, contaminants will continue to interact with the geosphere and investigations on long term changes and interactive processes is imperative to verify risks. In this presentation we provide a snap-shot of subsurface science research from the past 25 y that seeks to provide an improved understanding and predictive capability of multi-scale contaminant fate and transport processes in heterogeneous unsaturated and saturated environments. Investigations focus on coupled hydrological, geochemical, and microbial processes that control reactive contaminant transport and that involve multi-scale fundamental research ranging from the molecular scale (e.g. synchrotrons, electron sources, arrays) to in situ plume interrogation strategies at the macroscopic scale (e.g. geophysics, field biostimulation, coupled processes monitoring). We show how this fundamental research is used to provide multi-process, multi-scale predictive monitoring and modeling tools that can be used at contaminated sites to (1) inform and improve the technical basis for decision making, and (2) assess which sites are amenable to natural attenuation and which would benefit from source zone remedial intervention.

Comparison of Eh and H2 measurements for delineating redox processes in a contaminated aquifer

USGS Publications Warehouse

Chapelle, Francis H.; Haack, Sheridan K.; Adriaens, Peter; Henry, Mark A.; Bradley, Paul M.

1996-01-01

Measurements of oxidation-reduction potential (Eh) and concentrations of dissolved hydrogen (H2) were made in a shallow groundwater system contaminated with solvents and jet fuel to delineate the zonation of redox processes. Eh measurements ranged from +69 to -158 mV in a cross section of the contaminated plume and accurately delineated oxic from anoxic groundwater. Plotting measured Eh and pH values on an equilibrium stability diagram indicated that Fe(III) reduction was the predominant redox process in the anoxic zone and did not indicate the presence of methanogenesis and sulfate reduction. In contrast, measurements of H2concentrations indicated that methanogenesis predominated in heavily contaminated sediments near the water table surface (H2 ∼ 7.0 nM) and that the methanogenic zone was surrounded by distinct sulfate-reducing (H2 ∼ 1-4 nM) and Fe(III)-reducing (H2 ∼ 0.1-0.8 nM) zones. The presence of methanogenesis, sulfate reduction, and Fe(III) reduction was confirmed by the distribution of dissolved oxygen, sulfate, Fe(II), and methane in groundwater. These results show that H2 concentrations were more useful for identifying anoxic redox processes than Ehmeasurements in this groundwater system. However, H2-based redox zone delineations are more reliable when H2 concentrations are interpreted in the context of electron-acceptor (oxygen, nitrate, sulfate) availability and the presence of final products [Fe(II), sulfide, methane] of microbial metabolism.

New strains of oil-degrading microorganisms for treating contaminated soils and wastes

NASA Astrophysics Data System (ADS)

Muratova, A. Yu; Panchenko, L. V.; Semina, D. V.; Golubev, S. N.; Turkovskaya, O. V.

2018-01-01

Two new strains Achromobacter marplatensis101n and Acinetobacter sp. S-33, capable of degrading 49 and 46% of oil within 7 days were isolated, identified, and characterized. The application of A. marplatensis 101n in combination with ammonium nitrate (100 mg·kg-1) for 30 days of cultivation resulted in the degradation of 49% of the initial total petroleum hydrocarbon content (274 g·kg-1) in the original highly acid (pH 4.9) oil-contaminated waste. Up to 30% of oil sludge added to a liquid mineral medium at a concentration of 15% was degraded after 10 days of cultivation of A. marplatensis 101n. Application of yellow alfalfa (Medicago falcata L.) plants with Acinetobacter sp. S-33 for bioremediation of oil-sludge-contaminated soil improved the quality of cleanup in comparison with the bacterium- or plant-only treatment. Inoculation of Acinetobacter sp. S-33 increased the growth of both roots and shoots by more than 40%, and positively influenced the soil microflora. We conclude that the new oil-degrading strains, Acinetobacter sp. S-33 and A. marplatensis 101n, can serve as the basis for new bioremediation agents for the treatment of oil contaminated soils and waste.

Killing of Campylobacter on contaminated plastic and wooden cutting boards by glycerol monocaprate (monocaprin).

PubMed

Thormar, H; Hilmarsson, H

2010-09-01

Contamination in the kitchen with foodborne bacteria is a risk factor in human exposure to these pathogens, an important route being transfer of bacteria from contaminated cutting boards and other surfaces to humans. The aim of this study was to test microbicidal emulsions of glycerol monocaprate (monocaprin) against Campylobacter on contaminated cutting boards. Plastic and wooden cutting boards, soiled with meat juice heavily contaminated with Campylobacter, were treated for 2 min with emulsions of monocaprin (MC) made in water or in buffer at low pH. Viable Campylobacter counts were reduced below the detectable level on plastic board surfaces after treatment with MC emulsions with or without 1.25% washing-up liquids (WUL). The counts were also greatly reduced on wooden boards (P < 0.05). Monocaprin emulsions and mixtures of MC emulsions and WUL may be useful as sanitizers/disinfectants in kitchens and in other food preparing and processing facilities. Cleaning with MC emulsions with or without WUL may reduce the risk of human exposure to Campylobacter.

PERMEABLE REACTIVE BARRIER STRATEGIES FOR REMEDIATION OF ARSENIC-CONTAMINATED GROUNDWATER

EPA Science Inventory

Results are presented from laboratory batch tests using zero-valent iron to treat arsenic-contaminated groundwater. The laboratory tests were conducted using near- neutral pH groundwater from a contaminated aquifer located adjacent to a custom smelting facility. Experiments we...

Remediation of Groundwater Contaminated by Nuclear Waste

NASA Astrophysics Data System (ADS)

Parker, Jack; Palumbo, Anthony

2008-07-01

A Workshop on Accelerating Development of Practical Field-Scale Bioremediation Models; An Online Meeting, 23 January to 20 February 2008; A Web-based workshop sponsored by the U.S. Department of Energy Environmental Remediation Sciences Program (DOE/ERSP) was organized in early 2008 to assess the state of the science and knowledge gaps associated with the use of computer models to facilitate remediation of groundwater contaminated by wastes from Cold War era nuclear weapons development and production. Microbially mediated biological reactions offer a potentially efficient means to treat these sites, but considerable uncertainty exists in the coupled biological, chemical, and physical processes and their mathematical representation.

Fate of virginiamycin through the fuel ethanol production process

USDA-ARS?s Scientific Manuscript database

Antibiotics are frequently used to prevent and treat bacterial contamination of commercial fuel ethanol fermentations, but there is concern that antibiotic residues may persist in the distillers grains coproducts. A study to evaluate the fate of virginiamycin during the ethanol production process wa...

TREATING CHLORINATED WASTES WITH THE KPEG PROCESS

EPA Science Inventory

The two reports summarized here describe development of the alkali metal (polyethylene gylycolate (APEG) chemical technology to dechlorinate hazardous hydrocarbons in soils and its application at four demonstration sites: field-scale application to contaminated soils on the isla...

TREATMENT STUDIES OF CCL CONTAMINANTS

EPA Science Inventory

Bench-scale screening-level treatment data are presented for compounds listed in the Contaminant Candidate List (CCL). All of the CCl compounds are predicted to be economically removed by either activated carbon or air stripping technologies. To complete the screening-level treat...

SEMICONDUCTOR TECHNOLOGY A new cleaning process for the metallic contaminants on a post-CMP wafer's surface

NASA Astrophysics Data System (ADS)

Baohong, Gao; Yuling, Liu; Chenwei, Wang; Yadong, Zhu; Shengli, Wang; Qiang, Zhou; Baimei, Tan

2010-10-01

This paper presents a new cleaning process using boron-doped diamond (BDD) film anode electrochemical oxidation for metallic contaminants on polished silicon wafer surfaces. The BDD film anode electrochemical oxidation can efficiently prepare pyrophosphate peroxide, pyrophosphate peroxide can oxidize organic contaminants, and pyrophosphate peroxide is deoxidized into pyrophosphate. Pyrophosphate, a good complexing agent, can form a metal complex, which is a structure consisting of a copper ion, bonded to a surrounding array of two pyrophosphate anions. Three polished wafers were immersed in the 0.01 mol/L CuSO4 solution for 2 h in order to make comparative experiments. The first one was cleaned by pyrophosphate peroxide, the second by RCA (Radio Corporation of America) cleaning, and the third by deionized (DI) water. The XPS measurement result shows that the metallic contaminants on wafers cleaned by the RCA method and by pyrophosphate peroxide is less than the XPS detection limits of 1 ppm. And the wafer's surface cleaned by pyrophosphate peroxide is more efficient in removing organic carbon residues than RCA cleaning. Therefore, BDD film anode electrochemical oxidation can be used for microelectronics cleaning, and it can effectively remove organic contaminants and metallic contaminants in one step. It also achieves energy saving and environmental protection.

Periodic processes in vapor phase biofiltration

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

Moe, W.M.; Irvine, R.L.

1998-07-01

Most industrial processes and environmental remediation activities generate large volumes of air contaminated with low concentrations of volatile organic compounds. Carbon adsorption is the most widely used conventional treatment technology, but it has many drawbacks including secondary waste streams and excessive regeneration costs. Biofiltration, a microbial-based treatment technology, removes and biodegrades contaminants from a wide variety of waste streams without the disadvantages of carbon adsorption. In biofiltration, contaminated air flows through a packed bed containing microorganisms which convert contaminants primarily into carbon dioxide, water, and biomass. This paper describes how periodically operated, controlled unsteady state conditions were imposed on biofiltersmore » which used a new polyurethane foam medium that couples high porosity, suitable pore size, and low density with an ability to sorb water. The potential benefits associated with the controlled, unsteady-state operation of biofilters containing this new polyurethane foam medium are described herein. An example system treating a toluene contaminated waste gas is presented.« less

Treatment of urban river contaminated sediment with ex situ advanced oxidation processes: technical feasibility, environmental discharges and cost-performance analysis.

PubMed

Yan, Dickson Y S; Liu, Tongzhou; Lo, Irene M C

2015-01-01

The technical feasibility, environmental discharges and cost-performance of urban river contaminated sediment treatment with ex situ advanced oxidation processes were evaluated for the purpose of achieving an ideal treatment goal (for marine disposal) and a cost-performance treatment goal (for beneficially reusing as a filling material). Sediment samples were collected from a river located in southern China. To achieve the ideal treatment goal, sequential treatments (Fenton's reaction+activated persulphate oxidation) were carried out. One-step Fenton's reaction was applied to achieve the cost-performance treatment goal. The resulting effluent was treated and discharged, and sludge generated in wastewater treatment was characterized. The resources input throughout the treatment processes were recorded for cost estimation. After the treatment designed for achieving the ideal treatment goal, most pollutants fulfilled the treatment goal except Pb, Cd, Hg and Ag, probably because these four metals were present mainly in stable fractions of the sediment. The cost-performance treatment goal was achieved in view of low pollutant contents in the toxicity characteristic leaching procedure leachate of treated sediment. The cost for achieving the cost-performance treatment goal is much less than that for achieving the ideal treatment goal. The major cost difference is attributed to chemical cost. Stringent sediment treatment goals based on existing standards would lead to massive chemical use, complex treatment and hence huge cost. A simpler treatment with fewer chemicals is adequate for sediment beneficially reused as a filling material, and is economically more advantageous than handling sediment for marine disposal.

Sulfur transformations in pilot-scale constructed wetland treating high sulfate-containing contaminated groundwater: a stable isotope assessment.

PubMed

Wu, Shubiao; Jeschke, Christina; Dong, Renjie; Paschke, Heidrun; Kuschk, Peter; Knöller, Kay

2011-12-15

Current understanding of the dynamics of sulfur compounds inside constructed wetlands is still insufficient to allow a full description of processes involved in sulfur cycling. Experiments in a pilot-scale horizontal subsurface flow constructed wetland treating high sulfate-containing contaminated groundwater were carried out. Application of stable isotope approach combined with hydro-chemical investigations was performed to evaluate the sulfur transformations. In general, under inflow concentration of about 283 mg/L sulfate sulfur, sulfate removal was found to be about 21% with a specific removal rate of 1.75 g/m(2)·d. The presence of sulfide and elemental sulfur in pore water about 17.3 mg/L and 8.5 mg/L, respectively, indicated simultaneously bacterial sulfate reduction and re-oxidation. 70% of the removed sulfate was calculated to be immobilized inside the wetland bed. The significant enrichment of (34)S and (18)O in dissolved sulfate (δ(34)S up to 16‰, compared to average of 5.9‰ in the inflow, and δ(18)O up to 13‰, compared to average of 6.9‰ in the inflow) was observed clearly correlated to the decrease of sulfate loads along the flow path through experimental wetland bed. This enrichment also demonstrated the occurrence of bacterial sulfate reduction as well as demonstrated by the presence of sulfide in the pore water. Moreover, the integral approach shows that bacterial sulfate reduction is not the sole process controlling the isotopic composition of dissolved sulfate in the pore water. The calculated apparent enrichment factor (ɛ = -22‰) for sulfur isotopes from the δ(34)S vs. sulfate mass loss was significantly smaller than required to produce the observed difference in δ(34)S between sulfate and sulfide. It indicated some potential processes superimposing bacterial sulfate reduction, such as direct re-oxidation of sulfide to sulfate by oxygen released from plant roots and/or bacterial disproportionation of elemental sulfur. Furthermore

[Application of joint reconstruction with autogenous coronoid process graft to treat temporomandibular joint ankylosis].

PubMed

Xie, Qing-tiao; Huang, Xuan-ping; Jiang, Xian-fang; Yang, Yuan-yuan; Li, Hua; Lin, Xi

2013-08-01

To evaluate the clinical effect of joint reconstruction by using autogenous coronoid process graft to treat temporomandibular joint(TMJ) ankylosis. Nine cases of TMJ ankylosis from September 2008 to September 2010 were surgically treated by joint reconstruction with autogenous coronoid process graft, using autogenous articular disc or prosthodontic membrane as interpositional material. Mouth opening, occlusion and cone beam CT(CBCT) were used for evaluation before and after surgery. Satisfactory mouth opening was achieved in all patients and no one got occlusal changes or reankylosis during follow-up. CBCT showed that coronoid process graft reached bone union with the ramus and turned to be round. It is effective to cure TMJ ankylosis through joint reconstruction with autogenous coronoid process graft.

Combining sieving and washing, a way to treat MSWI boiler fly ash.

PubMed

De Boom, Aurore; Degrez, Marc

2015-05-01

Municipal Solid Waste Incineration (MSWI) fly ashes contain some compounds that could be extracted and valorised. A process based on wet sieving and washing steps has been developed aiming to reach this objective. Such unique combination in MSWI fly ash treatment led to a non-hazardous fraction from incineration fly ashes. More specifically, MSWI Boiler Fly Ash (BFA) was separately sampled and treated. The BFA finer particles (13wt%) were found to be more contaminated in Pb and Zn than the coarser fractions. After three washing steps, the coarser fractions presented leaching concentrations acceptable to landfill for non-hazardous materials so that an eventual subsequent valorisation may be foreseen. At the contrary, too much Pb leached from the finest particles and this fraction should be further treated. Wet sieving and washing permit thus to reduce the leachability of MSWI BFA and to concentrate the Pb and Zn contamination in a small (in particle size and volume) fraction. Such combination would therefore constitute a straightforward and efficient basis to valorise coarse particles from MSWI fly ashes. Copyright © 2015 Elsevier Ltd. All rights reserved.

[Biological treatments for contaminated soils: hydrocarbon contamination. Fungal applications in bioremediation treatment].

PubMed

Martín Moreno, Carmen; González Becerra, Aldo; Blanco Santos, María José

2004-09-01

Bioremediation is a spontaneous or controlled process in which biological, mainly microbiological, methods are used to degrade or transform contaminants to non or less toxic products, reducing the environmental pollution. The most important parameters to define a contaminated site are: biodegradability, contaminant distribution, lixiviation grade, chemical reactivity of the contaminants, soil type and properties, oxygen availability and occurrence of inhibitory substances. Biological treatments of organic contaminations are based on the degradative abilities of the microorganisms. Therefore the knowledge on the physiology and ecology of the biological species or consortia involved as well as the characteristics of the polluted sites are decisive factors to select an adequate biorremediation protocol. Basidiomycetes which cause white rot decay of wood are able to degrade lignin and a variety of environmentally persistent pollutants. Thus, white rot fungi and their enzymes are thought to be useful not only in some industrial process like biopulping and biobleaching but also in bioremediation. This paper provides a review of different aspects of bioremediation technologies and recent advances on ligninolytic metabolism research.

Contamination sources, serogroups, biofilm-forming ability and biocide resistance of Listeria monocytogenes persistent in tilapia-processing facilities.

PubMed

Vázquez-Sánchez, Daniel; Galvão, Juliana Antunes; Oetterer, Marília

2017-11-01

The major contamination sources, serogroups, biofilm-forming ability and biocide resistance of Listeria monocytogenes persistent in tilapia-processing facilities were assessed. Twenty-five processing-control points were examined twice in two factories, including whole tilapias, frozen fillets, water and food-contact surfaces. L. monocytogenes were detected in 4 and 20% of points of Factory A and B respectively, but at low concentrations. Contamination was due to inadequate handling of tilapias in the slaughter room of Factory A and to the application of ineffective sanitizing procedures in Factory B. Seven strains were characterized by RAPD-PCR using primers HLWL85, OPM-01 and DAF4. Genotypic similarity allowed tracing the contamination source of tilapia fillets in Factory B and detecting a prevalent strain in Brazilian tilapia-processing facilities. The serogroup II (including the serotype 1/2c) was the most frequently found, followed by serogroup I (1/2a) and III (1/2b), whereas the serotype 4b was not detected. All strains showed high biofilm-forming ability on stainless steel and polystyrene, but biofilm formation was positively correlated with the type of origin surface. Biofilms were highly resistant to peracetic acid and sodium hypochlorite, being required doses higher than those recommended by manufacturers to be eradicated. Peracetic acid was more effective than sodium hypochlorite, but the use of disinfectants with similar mechanisms of action increases the risk of cross-resistance. Case-by-case approaches are thus recommended to determine the sources and degree of contamination present in each factory, which would allow applying precise responses to control the persistence of bacterial pathogens such as L. monocytogenes .

Process for minimizing solids contamination of liquids from coal pyrolysis

DOEpatents

Wickstrom, Gary H.; Knell, Everett W.; Shaw, Benjamin W.; Wang, Yue G.

1981-04-21

In a continuous process for recovery of liquid hydrocarbons from a solid carbonaceous material by pyrolysis of the carbonaceous material in the presence of a particulate source of heat, particulate contamination of the liquid hydrocarbons is minimized. This is accomplished by removing fines from the solid carbonaceous material feed stream before pyrolysis, removing fines from the particulate source of heat before combining it with the carbonaceous material to effect pyrolysis of the carbonaceous material, and providing a coarse fraction of reduced fines content of the carbon containing solid residue resulting from the pyrolysis of the carbonaceous material before oxidizing carbon in the carbon containing solid residue to form the particulate source of heat.

Using Phytoremediation to Clean Up Contamination at Military Installations

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

Zellmer, S.D.; Hinchman, R.R.; Negri, M.C.

1997-07-01

During and following World War II, wastes from the production of munitions and other military materials were disposed of using the best available practices acceptable at that time. However, these disposal methods often contaminated soil and groundwater with organic compounds and metals that require cleanup under current regulations. An emerging technology for cleaning contaminated soils and shallow groundwater is phytoremediation, an environmentally friendly, low- cost, and low-tech process. Phytoremediation encompasses all plant- influenced biological, chemical, and physical processes that aid in the uptake, degradation, and metabolism of contaminants by either plants or free-living organisms in the plant`s rhizosphere. A phytoremediationmore » system can be viewed as a biological, solar-driven, pump-and-treat system with an extensive, self-extending uptake network (the root system) that enhances the soil and below-ground ecosystem for subsequent productive use. Argonne National Laboratory (ANL) has been conducting basic and applied research in phytoremediation since 1990. Initial greenhouse studies evaluated salt-tolerant wetland plants to clean UP and reduce the volume of salty `produced water` from petroleum wells. Results of these studies were used to design a bioreactor for processing produced water that is being demonstrated at a natural gas well in Oklahoma; this system can reduce produced water volume by about 75% in less than eight days, representing substantial savings in waste disposal cost. During 1994, ANL conducted a TNT plant uptake and in situ remediation study in a ridge-and-furrow area used for the disposal of pink water at the Joliet Army Ammunition Plant.« less

Landfill mining from a deposit of the chlorine/organochlorine industry as source of dioxin contamination of animal feed and assessment of the responsible processes.

PubMed

Torres, João Paulo Machado; Leite, Claudio; Krauss, Thomas; Weber, Roland

2013-04-01

In 1997, the Polychlorinated dibenzo-para-dioxin (PCDD)/Polychlorinated dibenzofuran (PCDF) concentrations in dairy products in Germany and other European countries increased. The PCDD/PCDF source was contaminated lime used in Brazilian citrus pulp pellets. The contaminated lime was mined from an industrial dump site. However, the detailed origin of the PCDD/PCDFs in the lime was not revealed. This paper investigates the contamination origin and describes the link between lime milk from the dumpsite of a chlorine/organochlorine industry and the contaminated lime. The contaminated lime stem from mining at the corporate landfill of Solvay Indupa in Sao Paulo. The landfill was used for 40 years for deposition of production residues and closed in 1996. The factory operated/operates at least two processes with potentially high PCDD/PCDFs releases namely the oxychlorination process for production of ethylene dichloride (EDC) and the chlor-alkali process. The main landfilled waste was lime milk (1.4 million tons) from the vinyl chloride monomer production (via the acetylene process) along with residues from other processes. The PCDD/PCDF fingerprint revealed that most samples from the chemical landfill showed an EDC PCDD/PCDF pattern with a characteristic octachlorodibenzofuran dominance. The PCDD/PCDF pattern of a Rio Grande sediment samples downstream the facility showed a chlor-alkali pattern with a minor impact of the EDC pattern. The case highlights that PCDD/PCDF- and persistent organic pollutants-contaminated sites need to be identified in a comprehensive manner as required by the Stockholm Convention (article 6) and controlled for their impact on the environment and human health. Landfill mining and reuse of materials from contaminated deposits should be prohibited.

Contamination analysis unit

DOEpatents

Gregg, Hugh R.; Meltzer, Michael P.

1996-01-01

The portable Contamination Analysis Unit (CAU) measures trace quantifies of surface contamination in real time. The detector head of the portable contamination analysis unit has an opening with an O-ring seal, one or more vacuum valves and a small mass spectrometer. With the valve closed, the mass spectrometer is evacuated with one or more pumps. The O-ring seal is placed against a surface to be tested and the vacuum valve is opened. Data is collected from the mass spectrometer and a portable computer provides contamination analysis. The CAU can be used to decontaminate and decommission hazardous and radioactive surface by measuring residual hazardous surface contamination, such as tritium and trace organics It provides surface contamination data for research and development applications as well as real-time process control feedback for industrial cleaning operations and can be used to determine the readiness of a surface to accept bonding or coatings.

Understanding Contamination; Twenty Years of Simulating Radiological Contamination

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

Emily Snyder; John Drake; Ryan James

A wide variety of simulated contamination methods have been developed by researchers to reproducibly test radiological decontamination methods. Some twenty years ago a method of non-radioactive contamination simulation was proposed at the Idaho National Laboratory (INL) that mimicked the character of radioactive cesium and zirconium contamination on stainless steel. It involved baking the contamination into the surface of the stainless steel in order to 'fix' it into a tenacious, tightly bound oxide layer. This type of contamination was particularly applicable to nuclear processing facilities (and nuclear reactors) where oxide growth and exchange of radioactive materials within the oxide layer becamemore » the predominant model for material/contaminant interaction. Additional simulation methods and their empirically derived basis (from a nuclear fuel reprocessing facility) are discussed. In the last ten years the INL, working with the Defense Advanced Research Projects Agency (DARPA) and the National Homeland Security Research Center (NHSRC), has continued to develop contamination simulation methodologies. The most notable of these newer methodologies was developed to compare the efficacy of different decontamination technologies against radiological dispersal device (RDD, 'dirty bomb') type of contamination. There are many different scenarios for how RDD contamination may be spread, but the most commonly used one at the INL involves the dispersal of an aqueous solution containing radioactive Cs-137. This method was chosen during the DARPA projects and has continued through the NHSRC series of decontamination trials and also gives a tenacious 'fixed' contamination. Much has been learned about the interaction of cesium contamination with building materials, particularly concrete, throughout these tests. The effects of porosity, cation-exchange capacity of the material and the amount of dirt and debris on the surface are very important factors. The interaction of

Hospital management of mass radiological casualties: reassessing exposures from contaminated victims of an exploded radiological dispersal device.

PubMed

Smith, James M; Ansari, Armin; Harper, Frederick T

2005-11-01

One of the key issues in the aftermath of an exploded radiological dispersal device from a terrorist event is that of the contaminated victim and the concern among healthcare providers for the harmful exposures they may receive in treating patients, especially if the patient has not been thoroughly decontaminated. This is critically important in the event of mass casualties from a nuclear or radiological incident because of the essential rapidity of acute medical decisions and that those who have life- or limb-threatening injuries may have treatment unduly delayed by a decontamination process that may be unnecessary for protecting the health and safety of the patient or the healthcare provider. To estimate potential contamination of those exposed in a radiological dispersal device event, results were used from explosive aerosolization tests of surrogate radionuclides detonated with high explosives at the Sandia National Laboratories. Computer modeling was also used to assess radiation dose rates to surgical personnel treating patients with blast injuries who are contaminated with any of a variety of common radionuclides. It is demonstrated that exceptional but plausible cases may require special precautions by the healthcare provider, even while managing life-threatening injuries of a contaminated victim from a radiological dispersal device event.

The effect of simulated acid rain on the stabilization of cadmium in contaminated agricultural soils treated with stabilizing agents.

PubMed

Zhu, Hao; Wu, Chunfa; Wang, Jun; Zhang, Xumei

2018-04-16

Stabilization technology is one of widely used remediation technologies for cadmium (Cd)-contaminated agricultural soils, but stabilized Cd in soil may be activated again when external conditions such as acid rain occurred. Therefore, it is necessary to study the effect of acid rain on the performance of different stabilizing agents on Cd-polluted agriculture soils. In this study, Cd-contaminated soils were treated with mono-calcium phosphate (MCP), mono-ammonium phosphate (MAP), and artificial zeolite (AZ) respectively and incubated 3 months. These treatments were followed by two types of simulated acid rain (sulfuric acid rain and mixed acid rain) with three levels of acidity (pH = 3.0, 4.0, and 5.6). The chemical forms of Cd in the soils were determined by Tessier's sequential extraction procedure, and the leaching toxicities of Cd in the soils were assessed by toxicity characteristic leaching procedure (TCLP). The results show that the three stabilizing agents could decrease the mobility of Cd in soil to some degree with or without simulated acid rain (SAR) treatment. The stabilization performances followed the order of AZ < MAP < MCP. Acid rain soaking promoted the activation of Cd in stabilized soil, and both anion composition and pH of acid rain were two important factors that influenced the stabilization effect of Cd.

TNT and RDX degradation and extraction from contaminated soil using subcritical water.

PubMed

Islam, Mohammad Nazrul; Shin, Moon-Su; Jo, Young-Tae; Park, Jeong-Hun

2015-01-01

The use of explosives either for industrial or military operations have resulted in the environmental pollution, poses ecological and health hazard. In this work, a subcritical water extraction (SCWE) process at laboratory scale was used at varying water temperature (100-175 °C) and flow rate (0.5-1.5 mL min(-1)), to treat 2,4,6-trinitrotoluene (TNT) and hexahydro-1,3,5-trinitro-1,3,5-triazine (RDX) contaminated soil, to reveal information with respect to the explosives removal (based on the analyses of soil residue after extraction), and degradation performance (based on the analyses of water extracts) of this process. Continuous flow subcritical water has been considered on removal of explosives to avoid the repartitioning of non-degraded compounds to the soil upon cooling which usually occurs in the batch system. In the SCWE experiments, near complete degradation of both TNT and RDX was observed at 175 °C based on analysis of water extracts and soil. Test results also indicated that TNT removal of >99% and a complete RDX removal were achieved by this process, when the operating conditions were 1 mL min(-1), and treatment time of 20 min, after the temperature reached 175 °C. HPLC-UV and ion chromatography analysis confirmed that the explosives underwent for degradation. The low concentration of explosives found in the process wastewater indicates that water recycling may be viable, to treat additional soil. Our results have shown in the remediation of explosives contaminated soil, the effectiveness of the continuous flow SCWE process. Copyright © 2014 Elsevier Ltd. All rights reserved.

Payload/orbiter contamination control requirement study: Preliminary contamination mission support plan. [a management analysis of project planning of spacecraft sterilization

NASA Technical Reports Server (NTRS)

Bareiss, L. E.; Hooper, V. W.; Ress, E. B.

1976-01-01

Progress is reported on the mission support plan and those support activities envisioned to be applicable and necessary during premission and postmission phases of the Spacelab program. The purpose, role, and requirements of the contamination control operations for the first two missions of the Spacelab equipped Space Transportation System are discussed. The organization of the contamination control operation and its relationship to and interfaces with other mission support functions is also discussed. Some specific areas of contamination to be investigated are treated. They are: (1) windows and viewports, (2) experiment equipment, (3) thermal control surfaces, (4) the contaminant induced atmosphere (as differentiated from the normal ambient atmosphere at the orbit altitude), and (5) optical navigation instruments.

Attention, processing speed, and executive functioning in pediatric brain tumor survivors treated with proton beam radiation therapy.

PubMed

Antonini, Tanya N; Ris, M Douglas; Grosshans, David R; Mahajan, Anita; Okcu, M Fatih; Chintagumpala, Murali; Paulino, Arnold; Child, Amanda E; Orobio, Jessica; Stancel, Heather H; Kahalley, Lisa S

2017-07-01

This study examines attention, processing speed, and executive functioning in pediatric brain tumor survivors treated with proton beam radiation therapy (PBRT). We examined 39 survivors (age 6-19years) who were 3.61years post-PBRT on average. Craniospinal (CSI; n=21) and focal (n=18) subgroups were analyzed. Attention, processing speed, and executive functioning scores were compared to population norms, and clinical/demographic risk factors were examined. As a group, survivors treated with focal PBRT exhibited attention, processing speed, and executive functioning that did not differ from population norms (all p>0.05). Performance in the CSI group across attention scales was normative (all p>0.05), but areas of relative weakness were identified on one executive functioning subtest and several processing speed subtests (all p<0.01). Survivors treated with PBRT may exhibit relative resilience in cognitive domains traditionally associated with radiation late effects. Attention, processing speed, and executive functioning remained intact and within normal limits for survivors treated with focal PBRT. Among survivors treated with CSI, a score pattern emerged that was suggestive of difficulties in underlying component skills (i.e., processing speed) rather than true executive dysfunction. No evidence of profound cognitive impairment was found in either group. Copyright © 2017 Elsevier B.V. All rights reserved.

Contamination analysis unit

DOEpatents

Gregg, H.R.; Meltzer, M.P.

1996-05-28

The portable Contamination Analysis Unit (CAU) measures trace quantities of surface contamination in real time. The detector head of the portable contamination analysis unit has an opening with an O-ring seal, one or more vacuum valves and a small mass spectrometer. With the valve closed, the mass spectrometer is evacuated with one or more pumps. The O-ring seal is placed against a surface to be tested and the vacuum valve is opened. Data is collected from the mass spectrometer and a portable computer provides contamination analysis. The CAU can be used to decontaminate and decommission hazardous and radioactive surfaces by measuring residual hazardous surface contamination, such as tritium and trace organics. It provides surface contamination data for research and development applications as well as real-time process control feedback for industrial cleaning operations and can be used to determine the readiness of a surface to accept bonding or coatings. 1 fig.

Advanced Oxidation Process sanitization of hatching eggs reduces Salmonella in broiler chicks.

PubMed

Rehkopf, A C; Byrd, J A; Coufal, C D; Duong, T

2017-10-01

The microbial quality of eggs entering the hatchery is an important critical control point for biosecurity, pathogen reduction, and food safety programs in poultry production. Developing interventions to reduce Salmonella contamination of eggs is important to improving the microbial food safety of poultry and poultry products. The hydrogen peroxide (H2O2) and ultraviolet light (UV) Advanced Oxidation Process (AOP) has been previously demonstrated to be effective in reducing Salmonella on the surface of experimentally contaminated eggs. The objective of this study was to evaluate the effect of treating eggs with an egg-sanitizing apparatus using the H2O2/UV AOP on Salmonella contamination during incubation, hatching, and in broiler chicks during grow-out. Experimentally contaminated eggs were treated using the automated H2O2/UV AOP egg sanitizer and incubated for 21 d. AOP sanitization reduced Salmonella up to 7 log10 cfu egg-1 (P < 0.05) from the surface of experimentally contaminated eggs and reduced the number of Salmonella positive eggs by up to 75% (P < 0.05) when treated 1 h post-inoculation. AOP treatment also reduced the number of Salmonella-positive eggs during incubation. Additionally, Salmonella was recovered from more chicks hatched from untreated eggs than from eggs treated using the H2O2/UV AOP egg sanitizer (P < 0.05) through 14 d posthatch. These data suggest reduction of Salmonella contamination on the surface of eggs using the H2O2/UV AOP egg sanitizer prior to incubation may reduce the gastrointestinal colonization of chicks by Salmonella. © 2017 Poultry Science Association Inc.

Post-consumer contamination in high-density polyethylene (HDPE) milk bottles and the design of a bottle-to-bottle recycling process.

PubMed

Welle, F

2005-10-01

Six hundred conventional recycled HDPE flake samples, which were recollected and sorted in the UK, were screened for post-consumer contamination levels. Each analysed sample consisted of 40-50 individual flakes so that the amount of analysed individual containers was in the range 24,000-30,000 post-consumer milk bottles. Predominant contaminants in hot-washed flake samples were unsaturated oligomers, which can be also be found in virgin high-density polyethylene (HDPE) pellet samples used for milk bottle production. In addition, the flavour compound limonene, the degradation product of antioxidant additives di-tert-butylphenol and low amounts of saturated oligomers were found in higher concentrations in the post-consumer samples in comparison with virgin HDPE. However, the overall concentrations in post-consumer recycled samples were similar to or lower than concentration ranges in comparison with virgin HDPE. Contamination with other HDPE untypical compounds was rare and was in most cases related to non-milk bottles, which are <2.1% of the input material of the recycling process. The maximum concentration found in one sample of 1 g was estimated as 130 mg kg(-1), which corresponds to a contamination of 5200-6500 mg kg(-1) in the individual bottle. The recycling process investigated was based on an efficient sorting process, a hot-washing of the ground bottles, and a further deep-cleaning of the flakes with high temperatures and vacuum. Based on the fact that the contamination levels of post-consumer flake samples are similar to virgin HDPE and on the high cleaning efficiency of the super-clean recycling process especially for highly volatile compounds, the recycling process investigated is suitable for recycled post-consumer HDPE bottles for direct food-contact applications. However, hand-picking after automatically sorting is recommended to decrease the amount of non-milk bottles. The conclusions for suitability are valid, provided that the migration testing of

BIOREMEDIATION OF OIL-CONTAMINATED FINE SEDIMENTS.

EPA Science Inventory

Bioremediation of oil contamination has been shown to be effective for cobble and sandy shorelines. To assess the operational limitations of this technology, this project studied its potential to treat buried oil in fine sediments. The effectiveness of bioremediation by nutrient ...

Arsenic Remediation Enhancement Through Chemical Additions to Pump and Treat Operations

NASA Astrophysics Data System (ADS)

Wovkulich, K.; Mailloux, B. J.; Stute, M.; Simpson, H. J.; Keimowitz, A. R.; Powell, A.; Lacko, A.; Chillrud, S. N.

2008-12-01

Arsenic is a contaminant found at more than 500 US Superfund sites. Since pump and treat technologies are widely used for remediation of contaminated groundwater, increasing the efficiency of contaminant removal at such sites should allow limited financial resources to clean up more sites. The Vineland Chemical Company Superfund site is extensively contaminated with arsenic after waste arsenic salts were stored and disposed of improperly for much of the company's 44 year manufacturing lifetime. Despite approximately eight years of pump and treat remediation, arsenic concentrations in the recovery wells can still be greater than 1000 ppb. The arsenic concentrations in the groundwater remain high because of slow desorption of arsenic from contaminated aquifer solids. Extrapolation of laboratory column experiments suggest that continuing the current groundwater remediation practice based on flushing ambient groundwater through the system may require on the order of hundreds of years to clean the site. However, chemical additions of phosphate or oxalic acid into the aquifer could decrease the remediation time scale substantially. Laboratory results from a soil column experiment using input of 10 mM oxalic acid suggest that site clean up of groundwater could be decreased to as little as four years. Pilot scale forced gradient field experiments will help establish whether chemical additions can be effective for increasing arsenic mobilization from aquifer solids and thus substantially decrease pump and treat clean up time.

Importance of microscopy in durability studies of solidified and stabilized contaminated soils

USGS Publications Warehouse

Klich, I.; Wilding, L.P.; Drees, L.R.; Landa, E.R.

1999-01-01

Solidification/stabilization (S/S) is recognized by the U.S. EPA as a best demonstrated available technology for the containment of contaminated soils and other hazardous wastes that cannot be destroyed by chemical, thermal, or biological means. Despite the increased use of S/S technologies, little research has been conducted on the weathering and degradation of solidified and stabilized wastes once the treated materials have been buried. Published data to verify the performance and durability of landfilled treated wastes over time are rare. In this preliminary study, optical and electron microscopy (scanning electron microscopy [SEM], transmission electron microscopy [TEM] and electron probe microanalyses [EPMA]) were used to evaluate weathering features associated with metal-bearing contaminated soil that had been solidified and stabilized with Portland cement and subsequently buried on site, stored outdoors aboveground, or achieved in a laboratory warehouse for up to 6 yr. Physical and chemical alteration processes identified include: freeze-thaw cracking, cracking caused by the formation of expansive minerals such as ettringite, carbonation, and the movement of metals from waste aggregates into the cement micromass. Although the extent of degradation after 6 yr is considered slight to moderate, results of this study show that the same environmental concerns that affect the durability of concrete must be considered when evaluating the durability and permanence of the solidification and stabilization of contaminated soils with cement. In addition, such evaluations cannot be based on leaching and chemical analyses alone. The use of all levels of microscopic analyses must be incorporated into studies of the long-term performance of S/S technologies.Solidification/stabilization (S/S) is recognized by the U.S. EPA as a best demonstrated available technology for the containment of contaminated soils and other hazardous wastes that cannot be destroyed by chemical

Ultraviolet absorption of common spacecraft contaminants. [to control effects of contaminants on optical systems

NASA Technical Reports Server (NTRS)

Colony, J. A.

1979-01-01

Organic contamination of ultraviolet optical systems is discussed. Degradation of signal by reflection, scattering, interference, and absorption is shown. The first three processes depend on the physical state of the contaminant while absorption depends on its chemical structure. The latter phenomenon is isolated from the others by dissolving contaminants in cyclohexane and determining absorption spectra from 2100A to 3600A. A variety of materials representing the types of contaminants responsible for most spaceflight hardware problems is scanned and the spectra is presented. The effect of thickness is demonstrated for the most common contaminant, di(2 ethyl hexyl)phthalate, by scanning successive dilutions.

Effects of oral exposure to sodium sulphite-treated deoxynivalenol (DON)-contaminated maize on performance and plasma concentrations of toxins and metabolites in piglets.

PubMed

Paulick, Marleen; Winkler, Janine; Kersten, Susanne; Schatzmayr, Dian; Frahm, Jana; Kluess, Jeannette; Schwartz-Zimmermann, Heidi Elisabeth; Dänicke, Sven

2018-02-01

The objective of the present study was to demonstrate the efficiency of the decontamination process applied to deoxynivalenol (DON)-contaminated maize by sodium sulphite (Na 2 SO 3 ) treatment in vivo. Additionally, in vitro characterisation of the toxicity of the DON sulphonates (DONS 1, 2 and 3 denote structurally different forms), the resulting DON metabolites, on peripheral blood mononuclear cells (PBMC) should substantiate the inactivation of DON. In a piglet experiment, both DON-contaminated maize and -uncontaminated control maize either untreated (DON-, CON-) or Na 2 SO 3 -treated (DON+, CON+) were mixed into feed and fed for 42 d starting from weaning. The results showed that feed intake and daily weight gain of animals fed DON- were significantly lower compared to animals fed CON- and CON+, whereas group DON+ reached the control level or even exceeded it. The feed-to-gain ratio was unaffected (p = 0.45). Furthermore, DON concentrations in plasma markedly reflected the diets' DON concentrations. These were < 0.1, < 0.1, 5.4 and 0.8 mg/kg feed for CON-, CON+, DON- and DON+, and amounted to 0.3, 0.4, 33.0 and 9.3 ng/ml in plasma, respectively. Whereas DONS 2 and 3 were detected in the DON+ diet, only DONS 2 was recovered in plasma. Regarding the toxicity of DONS, no or much lower toxicity was found compared to DON. DONS 1 and Na 2 SO 3 did not affect the viability of PBMC. At 32.71μM DONS2 the viability was reduced by 50% and thus this compound was less toxic than DON by a factor of 73. Consequently, wet preservation of maize with Na 2 SO 3 was an effective tool to avoid the adverse effects of DON on performance of piglets.

Temporal variations in parameters reflecting terminal-electron-accepting processes in an aquifer contaminated with waste fuel and chlorinated solvents

USGS Publications Warehouse

McGuire, Jennifer T.; Smith, Erik W.; Long, David T.; Hyndman, David W.; Haack, Sheridan K.; Klug, Michael J.; Velbel, Michael A.

2000-01-01

A fundamental issue in aquifer biogeochemistry is the means by which solute transport, geochemical processes, and microbiological activity combine to produce spatial and temporal variations in redox zonation. In this paper, we describe the temporal variability of TEAP conditions in shallow groundwater contaminated with both waste fuel and chlorinated solvents. TEAP parameters (including methane, dissolved iron, and dissolved hydrogen) were measured to characterize the contaminant plume over a 3-year period. We observed that concentrations of TEAP parameters changed on different time scales and appear to be related, in part, to recharge events. Changes in all TEAP parameters were observed on short time scales (months), and over a longer 3-year period. The results indicate that (1) interpretations of TEAP conditions in aquifers contaminated with a variety of organic chemicals, such as those with petroleum hydrocarbons and chlorinated solvents, must consider additional hydrogen-consuming reactions (e.g., dehalogenation); (2) interpretations must consider the roles of both in situ (at the sampling point) biogeochemical and solute transport processes; and (3) determinations of microbial communities are often necessary to confirm the interpretations made from geochemical and hydrogeological measurements on these processes.

Identification of critical contaminants in wastewater effluent for managed aquifer recharge.

PubMed

Yuan, Jie; Van Dyke, Michele I; Huck, Peter M

2017-04-01

Managed aquifer recharge (MAR) using highly treated effluent from municipal wastewater treatment plants has been recognized as a promising strategy for indirect potable water reuse. Treated wastewater effluent can contain a number of residual contaminants that could have adverse effects on human health, and some jurisdictions have regulations in place to govern these. For those that do not, but where reuse may be under consideration, it is of crucial importance to develop a strategy for identifying priority contaminants, which can then be used to understand the water treatment technologies that might be required. In this study, a multi-criteria approach to identify critical contaminants in wastewater effluent for MAR was developed and applied using a case study site located in southern Ontario, Canada. An important aspect of this approach was the selection of representative compounds for each group of contaminants, based on potential for occurrence in wastewater and expected health or environmental impacts. Due to a lack of MAR regulations in Canada, the study first proposed potential recharge water quality targets. Predominant contaminants, potential additional contaminants, and potential emerging contaminants, which together comprise critical contaminants for MAR with reclaimed water, were then selected based on the case study wastewater effluent monitoring data and literature data. This paper proposes an approach for critical contaminant selection, which will be helpful to guide future implementation of MAR projects using wastewater treatment plant effluents. Copyright © 2016 Elsevier Ltd. All rights reserved.

Use of Zn isotopes as a probe of anthropogenic contamination and biogeochemical processes in the Seine River, France

NASA Astrophysics Data System (ADS)

Chen, J.; Gaillardet, J.; Louvat, P.; Birck, J.

2009-05-01

Metal contamination is a major issue of human impact on the aqueous environment. River water is particularly susceptible to contamination for both dissolved and particulate loads, displaying a major challenge in understanding the dominant sources and pathways of metals in polluted drainage basins. Recent improvements in mass spectrometry allow isotopic measurements of "non-traditional" metals (Zn, Cu, Fe, etc.), making their isotopes a new potential device to investigate contamination of metals under dissolved and particulate forms in rivers. We focus here on Zn isotope geochemistry in the largely anthropized Seine River (France). A new protocol of two-column separation of Zn from dilute aqueous solution has been developed and proven to be reproducible and satisfactory for accurate measurement of Zn isotopic ratios in water samples by MC-ICP-MS (2σ = 0.04‰). Preliminary results show a total variation of 0.65‰ for δ66Zn in dissolved phases of the Seine basin, and a light isotope enrichment in anthropogenic sources compared to other water samples. The determined conservative behavior of Zn in river water makes its isotopes an effective probe of anthropogenic contamination. The natural and anthropogenic inputs were clearly identified and calculated based on Zn isotope compositions for dissolved loads. Suspended particular matters (SPM) display different Zn isotope compositions compared to dissolved loads, with a total δ66Zn variation of 0.22‰. Zn concentrations and its isotope compositions in SPM reveal inverse relationships as function of the distance from the headwater and the SPM content for geographical and temporal samples, respectively. The δ66Zn data in SPM are interpreted as reflecting the mixture of natural and anthropogenic particles. The correlation between dissolved and particulate δ66Zn shows that adsorption processes are not the dominant process making Zn enrichment in SPM. We report here for the first time systematic δ66Zn data in waters of

Assessment of sediment mutagenicity in areas under the influence of a contaminated site undergoing a remediation process.

PubMed

Gameiro, Paula Hauber; Pereira, Naiara Costa; Rocha, Jocelita Aparecida Vaz; Leal, Karen Alam; Vargas, Vera Maria Ferrão

2018-04-10

Soil contamination enters aquatic ecosystems affecting sediment quality. The region studied is the Taquari River, Brazil, close to a site contaminated by wood preservatives, with a runoff route into the river. The first stage of the remediation process (In this article, the terms intervention and remediation have been used with slightly different meanings. We consider intervention to be the first phase of the remediation process, which aims to remove active sources) was an intervention to remove the main active sources. The Salmonella/microsome assay and polycyclic aromatic hydrocarbons (PAHs) were used to assess sediment quality in organic extracts during different intervention phases. The strains used were TA98, TA97a, and TA100 with and without S9mix (±S9). The results indicated the presence of pro-mutagens at site Ta010 (closest to the contaminated site) in all samplings, and the highest result occurred before intervention for TA100 + S9 (1,672 ± 215.9 rev/g). These values decreased during (83 ± 23.6 rev/g) and after this process (403 ± 105.9 rev/g), although the PAHs concentrations increased. Samples from this site presented PAHs with a carcinogenic potential during the assessed periods. After intervention, Ta006 (4 km downstream from Ta010) showed the most significant mutagenesis for TA100 + S9 (764 ± 230.2 rev/g) and, although the total PAHs values were lower, the species considered carcinogenic had higher concentrations. Mutagenesis predicted values of PAHs confirmed that carcinogenic species were predominantly detected by TA100, and the other PAHs by TA97a strains. Marked contaminant release to the river was observed, mainly in Ta010 at different periods. Mutagenicity and PAHs values in an internal stream, upstream from Ta010, showed a dispersion route of these agents. Thus, contamination in Ta010 and possible contribution to Ta006, after intervention, provides a warning regarding environmental quality in the region. Environ

Remediation of Pb/Cr co-contaminated soil using electrokinetic process and approaching electrode technique.

PubMed

Ng, Yee-Sern; Sen Gupta, Bhaskar; Hashim, Mohd Ali

2016-01-01

Electrokinetic process has emerged as an important tool for remediating heavy metal-contaminated soil. The process can concentrate heavy metals into smaller soil volume even in the absence of hydraulic flow. This makes it an attractive soil pre-treatment method before other remediation techniques are applied such that the chemical consumption in the latter stage can be reduced. The present study evaluates the feasibility of electrokinetic process in concentrating lead (Pb) and chromium (Cr) in a co-contaminated soil using different types of wetting agents, namely 0.01 M NaNO3, 0.1 M citric acid and 0.1 M EDTA. The data obtained showed that NaNO3 and citric acid resulted in poor Pb electromigration in this study. As for Cr migration, these agents were also found to give lower electromigration rate especially at low pH region as a result of Cr(VI) adsorption and possible reduction into Cr(III). In contrast, EDTA emerged as the best wetting agent in this study as it formed water-soluble anionic complexes with both Pb and Cr. This provided effective one-way electromigration towards the anode for both ions, and they were accumulated into smaller soil volume with an enrichment ratio of 1.55-1.82. A further study on the application of approaching cathode in EDTA test showed that soil alkalisation was achieved, but this did not provide significant enhancement on electromigration for Pb and Cr. Nevertheless, the power consumption for electrokinetic process was decreased by 22.5%.

The redox processes in Hg-contaminated soils from Descoberto (Minas Gerais, Brazil): implications for the mercury cycle.

PubMed

Windmöller, Cláudia C; Durão Júnior, Walter A; de Oliveira, Aline; do Valle, Cláudia M

2015-02-01

Investigations of the redox process and chemical speciation of Hg(II) lead to a better understanding of biogeochemical processes controlling the transformation of Hg(II) into toxic and bioaccumulative monomethyl mercury, mainly in areas contaminated with Hg(0). This study investigates the speciation and redox processes of Hg in soil samples from a small area contaminated with Hg(0) as a result of gold mining activities in the rural municipality of Descoberto (Minas Gerais, Brazil). Soil samples were prepared by adding Hg(0) and HgCl2 separately to dry soil, and the Hg redox process was monitored using thermodesorption coupled to atomic absorption spectrometry. A portion of the Hg(0) added was volatilized (up to 37.4±2.0%) or oxidized (from 36±7% to 88±16%). A correlation with Mn suggests that this oxidation is favored, but many other factors must be evaluated, such as the presence of microorganisms and the types of organic matter present. The interaction of Hg with the matrix is suggested to involve Hg(II)-complexes formed with inorganic and organic sulfur ligands and/or nonspecific adsorption onto oxides of Fe, Al and/or Mn. The kinetics of the oxidation reaction was approximated for two first-order reactions; the faster reaction was attributed to the oxidation of Hg(0)/Hg(I), and the slower reaction corresponded to Hg(I)/Hg(II). The second stage was 43-139 times slower than the first. The samples spiked with Hg(II) showed low volatilization and a shifting of the signal of Hg(II) to lower temperatures. These results show that the extent, rate and type of redox process can be adverse in soils. Descoberto can serve as an example for areas contaminated with Hg(0). Copyright © 2014 Elsevier Inc. All rights reserved.

Stable-Isotope Probing of Bacteria Capable of Degrading Salicylate, Naphthalene, or Phenanthrene in a Bioreactor Treating Contaminated Soil

PubMed Central

Singleton, David R.; Powell, Sabrina N.; Sangaiah, Ramiah; Gold, Avram; Ball, Louise M.; Aitken, Michael D.

2005-01-01

[13C6]salicylate, [U-13C]naphthalene, and [U-13C]phenanthrene were synthesized and separately added to slurry from a bench-scale, aerobic bioreactor used to treat soil contaminated with polycyclic aromatic hydrocarbons. Incubations were performed for either 2 days (salicylate, naphthalene) or 7 days (naphthalene, phenanthrene). Total DNA was extracted from the incubations, the “heavy” and “light” DNA were separated, and the bacterial populations associated with the heavy fractions were examined by denaturing gradient gel electrophoresis (DGGE) and 16S rRNA gene clone libraries. Unlabeled DNA from Escherichia coli K-12 was added to each sample as an internal indicator of separation efficiency. While E. coli was not detected in most analyses of heavy DNA, a low number of E. coli sequences was recovered in the clone libraries associated with the heavy DNA fraction of [13C]phenanthrene incubations. The number of E. coli clones recovered proved useful in determining the relative amount of light DNA contamination of the heavy fraction in that sample. Salicylate- and naphthalene-degrading communities displayed similar DGGE profiles and their clone libraries were composed primarily of sequences belonging to the Pseudomonas and Ralstonia genera. In contrast, heavy DNA from the phenanthrene incubations displayed a markedly different DGGE profile and was composed primarily of sequences related to the Acidovorax genus. There was little difference in the DGGE profiles and types of sequences recovered from 2- and 7-day incubations with naphthalene, so secondary utilization of the 13C during the incubation did not appear to be an issue in this experiment. PMID:15746319

First evaluation of alkylpyrazine application as a novel method to decrease microbial contaminations in processed meat products.

PubMed

Schöck, Matthias; Liebminger, Stefan; Berg, Gabriele; Cernava, Tomislav

2018-04-03

Every year about 20% of the globally produced meat gets lost due to microbial spoilage. Nevertheless, the demand for processed meat is constantly rising and producers are searching for novel strategies to reduce microbial contaminations in their products. In the present study, we evaluated the applicability of alkylpyrazines as antimicrobial agents. These fragrant molecules naturally occur in different vegetables, fruits, roasted nut and meat. Several pyrazine derivatives are readily added to processed products for flavoring purposes in the food industry. To evaluate their potential for application, two derivatives were tested for their antimicrobial activity against meat-associated bacterial contaminants and chicken meat as a whole. Isolates assigned to Carnobacteriaceae, Enterobacteriaceae, Listeriaceae, and Moraxellaceae were substantially inhibited in the pilot tests. Moreover, treatments of pyrazine-susceptible isolates resulted in 4-log reductions in bacterial cell counts. The effect was more pronounced when the model contaminants were exposed to higher concentrations of 5-isobutyl-2,3-dimethylpyrazine. In a first small-scale application with processed chicken meat, it was demonstrated that the antimicrobial effects of 2-isobutyl-3-methylpyrazine can be improved by additionally lowering the water activity on the meat surface when maltodextrin is used as a carrier substance. At low pyrazine dosages, the number of viable bacteria was decreased up to 95% in comparison to the corresponding controls. A complementary imaging method that was developed to assess the efficacy on the product, reinforced the applicability of this two-component system.

Effects of coal contamination on early life history processes of a reef-building coral, Acropora tenuis.

PubMed

Berry, Kathryn L E; Hoogenboom, Mia O; Brinkman, Diane L; Burns, Kathryn A; Negri, Andrew P

2017-01-15

Successful reproduction and larval dispersal are important for the persistence of marine invertebrate populations, and these early life history processes can be sensitive to marine pollution. Coal is emerging as a contaminant of interest due to the proximity of ports and shipping lanes to coral reefs. To assess the potential hazard of this contaminant, gametes, newly developed embryos, larvae and juveniles of the coral Acropora tenuis were exposed to a range of coal leachate, suspended coal, and coal smothering treatments. Fertilisation was the most sensitive reproductive process tested. Embryo survivorship decreased with increasing suspended coal concentrations and exposure duration, effects on larval settlement varied between treatments, while effects on juvenile survivorship were minimal. Leachate exposures had negligible effects on fertilisation and larval settlement. These results indicate that coral recruitment could be affected by spills that produce plumes of suspended coal particles which interact with gametes and embryos soon after spawning. Copyright © 2016 The Authors. Published by Elsevier Ltd.. All rights reserved.

Chemical Enhancements to Pump-and-Treat Remediation

EPA Pesticide Factsheets

The intent of this document is to explore the use of chemical enhancement to improve groundwater remediation efficiencies using pump-and-treat technologies, and point out arenas of contamination where such techniques are not practical.

Toxicological benchmarks for potential contaminants of concern for effects on soil and litter invertebrates and heterotrophic process

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

Will, M.E.; Suter, G.W. II

1995-09-01

An important step in ecological risk assessments is screening the chemicals occur-ring on a site for contaminants of potential concern. Screening may be accomplished by comparing reported ambient concentrations to a set of toxicological benchmarks. Multiple endpoints for assessing risks posed by soil-borne contaminants to organisms directly impacted by them have been established. This report presents benchmarks for soil invertebrates and microbial processes and addresses only chemicals found at United States Department of Energy (DOE) sites. No benchmarks for pesticides are presented. After discussing methods, this report presents the results of the literature review and benchmark derivation for toxicity tomore » earthworms (Sect. 3), heterotrophic microbes and their processes (Sect. 4), and other invertebrates (Sect. 5). The final sections compare the benchmarks to other criteria and background and draw conclusions concerning the utility of the benchmarks.« less

Ex situ bioremediation of oil-contaminated soil.

PubMed

Lin, Ta-Chen; Pan, Po-Tsen; Cheng, Sheng-Shung

2010-04-15

An innovative bioprocess method, Systematic Environmental Molecular Bioremediation Technology (SEMBT) that combines bioaugmentation and biostimulation with a molecular monitoring microarray biochip, was developed as an integrated bioremediation technology to treat S- and T-series biopiles by using the landfarming operation and reseeding process to enhance the bioremediation efficiency. After 28 days of the bioremediation process, diesel oil (TPH(C10-C28)) and fuel oil (TPH(C10-C40)) were degraded up to approximately 70% and 63% respectively in the S-series biopiles. When the bioaugmentation and biostimulation were applied in the beginning of bioremediation, the microbial concentration increased from approximately 10(5) to 10(6) CFU/g dry soil along with the TPH biodegradation. Analysis of microbial diversity in the contaminated soils by microarray biochips revealed that Acinetobacter sp. and Pseudomonas aeruginosa were the predominant groups in indigenous consortia, while the augmented consortia were Gordonia alkanivorans and Rhodococcus erythropolis in both series of biopiles during bioremediation. Microbial respiration as influenced by the microbial activity reflected directly the active microbial population and indirectly the biodegradation of TPH. Field experimental results showed that the residual TPH concentration in the complex biopile was reduced to less than 500 mg TPH/kg dry soil. The above results demonstrated that the SEMBT technology is a feasible alternative to bioremediate the oil-contaminated soil. Crown Copyright 2009. Published by Elsevier B.V. All rights reserved.

DEMONSTRATION BULLETIN: SOLIDIFICATION/STABILIZATION OF ORGANIC/INORGANIC CONTAMINANTS - SILICATE TECHNOLOGY CORPORATION

EPA Science Inventory

Silicate Technology Corporation's (STC's) technology for treating hazardous waste utilizes silicate compounds to stabilize organic and inorganic constituents in contaminated soils and sludges. STC has developed two groups of reagents: SOILSORB HM for treating wastes with inorgan...

Ecotoxicity of arsenic contaminated sludge after mixing with soils and addition into composting and vermicomposting processes.

PubMed

Vašíčková, Jana; Maňáková, Blanka; Šudoma, Marek; Hofman, Jakub

2016-11-05

Sludge coming from remediation of groundwater contaminated by industry is usually managed as hazardous waste despite it might be considered for further processing as a source of nutrients. The ecotoxicity of phosphorus rich sludge contaminated with arsenic was evaluated after mixing with soil and cultivation with Sinapis alba, and supplementation into composting and vermicomposting processes. The Enchytraeus crypticus and Folsomia candida reproduction tests and the Lactuca sativa root growth test were used. Invertebrate bioassays reacted sensitively to arsenic presence in soil-sludge mixtures. The root elongation of L. sativa was not sensitive and showed variable results. In general, the relationship between invertebrate tests results and arsenic mobile concentration was indicated in majority endpoints. Nevertheless, significant portion of the results still cannot be satisfactorily explained by As chemistry data. Composted and vermicomposted sludge mixtures showed surprisingly high toxicity on all three tested organisms despite the decrease in arsenic mobility, probably due to toxic metabolites of bacteria and earthworms produced during these processes. The results from the study indicated the inability of chemical methods to predict the effects of complex mixtures on living organisms with respect to ecotoxicity bioassays. Copyright © 2016 Elsevier B.V. All rights reserved.

Bond Testing for Effects of Silicone Contamination

NASA Technical Reports Server (NTRS)

Plaia, James; Evans, Kurt

2005-01-01

In 2003 ATK Thiokol discovered that the smocks and coveralls worn by its operations personnel for safety and contamination control were themselves contaminated with a silicone defoamer and a silicone oil. As a growing list of items have been identified as having this form of contamination, it was desirable to devise a test method to determine if the contamination level detected could cause subsequent processing concerns. The smocks and coveralls could potentially contact bonding surfaces during processing so the test method focused on dry transfer of the silicone from the clothing to the bonding surface.

Biosurfactant technology for remediation of cadmium and lead contaminated soils.

PubMed

Juwarkar, Asha A; Nair, Anupa; Dubey, Kirti V; Singh, S K; Devotta, Sukumar

2007-08-01

This research focuses on column experiments conducted to evaluate the potential of environmentally compatible rhamnolipid biosurfactant produced by Pseudomonas aeruginosa strain BS2 to remove heavy metals (Cd and Pb) from artificially contaminated soil. Results have shown that di-rhamnolipid removes not only the leachable or available fraction of Cd and Pb but also the bound metals as compared to tap water which removed the mobile fraction only. Washing of contaminated soil with tap water revealed that approximately 2.7% of Cd and 9.8% of Pb in contaminated soil was in freely available or weakly bound forms whereas washing with rhamnolipid removed 92% of Cd and 88% of Pb after 36 h of leaching. This indicated that di-rhamnolipid selectively favours mobilization of metals in the order of Cd>Pb. Biosurfactant specificity observed towards specific metal will help in preferential elution of specific contaminant using di-rhamnolipid. It was further observed that pH of the leachates collected from heavy metal contaminated soil column treated with di-rhamnolipid solution was low (6.60-6.78) as compared to that of leachates from heavy metal contaminated soil column treated with tap water (pH 6.90-7.25), which showed high dissolution of metal species from the contaminated soil and effective leaching of metals with treatment with biosurfactant. The microbial population of the contaminated soil was increased after removal of metals by biosurfactant indicating the decrease of toxicity of metals to soil microflora. This study shows that biosurfactant technology can be an effective and nondestructive method for bioremediation of cadmium and lead contaminated soil.

Process for gamma ray induced degradation of polychlorinated biphenyls

DOEpatents

Meikrantz, David H.; Mincher, Bruce J.; Arbon, Rodney E.

1998-01-01

The invention is a process for the in-situ destruction of polychlorinated biphenyl (PCB) compounds in transformer oils and transformers. These compounds are broken down selectively by irradiation of the object or mixture using spent nuclear fuel or any isotopic source of high energy gamma radiation. For example, the level of applied dose required to decompose 400 ppm of polychlorinated biphenyl in transformer oil to less than 50 ppm is 500 kilogray. Destruction of polychlorinated biphenyls to levels of less than 50 ppm renders the transformer oil or transformer non-PCB contaminated under current regulations. Therefore, this process can be used to treat PCB contaminated oil and equipment to minimize or eliminate the generation of PCB hazardous waste.

Decontamination of Petroleum-Contaminated Soils Using The Electrochemical Technique: Remediation Degree and Energy Consumption.

PubMed

Streche, Constantin; Cocârţă, Diana Mariana; Istrate, Irina-Aura; Badea, Adrian Alexandru

2018-02-19

Currently, there are different remediation technologies for contaminated soils, but the selection of the best technology must be not only the treatment efficiency but also the energy consumption (costs) during its application. This paper is focused on assessing energy consumption related to the electrochemical treatment of polluted soil with petroleum hydrocarbons. In the framework of a research project, two types of experiments were conducted using soil that was artificially contaminated with diesel fuel at the same level of contamination. The experimental conditions considered for each experiment were: different amounts of contaminated soils (6 kg and 18 kg, respectively), the same current intensity level (0.25A and 0.5A), three different contamination degrees (1%, 2.5% and 5%) and the same time for application of the electrochemical treatment. The remediation degree concerning the removal of petroleum hydrocarbons from soil increased over time by approximately 20% over 7 days. With regard to energy consumption, the results revealed that with an increase in the quantity of treated soil of approximately three times, the specific energy consumption decreased from 2.94 kWh/kg treated soil to 1.64 kWh/kg treated soil.

Extraction behavior of metallic contaminants and soil constituents from contaminated soils.

PubMed

Tokunaga, S; Park, S W; Ulmanu, M

2005-06-01

With an aim of developing an effective remediation technology for soils contaminated by heavy metals and metalloids, the extraction behavior of metallic contaminants as well as those of soil constituents was studied on a laboratory scale. Three contaminated soils collected from a former metal recycling plant were examined. These three soils were found to be contaminated by As, Cu, Pb, Sb, Se and Zn as compared to the non-contaminated soil. The pH-dependent extraction behavior of various elements from the soils was measured in a wide pH range and categorized into three groups. Hydrochloric acid (HCl), H2SO4, H3PO4, HNO3, sodium citrate, sodium tartrate, disodium dihydrogen ethylenediaminetetraacetate and diethylenetriaminepentaacetic acid were evaluated as extractants for removing contaminants from the soils. Extraction behavior of the soil constituents was also studied. The efficiency of the extraction was evaluated by the Japanese content and leaching tests. The stabilization of Pb remaining in the soil after the extraction process was conducted by the addition of iron(III) and calcium chloride.

Impact of food processing and detoxification treatments on mycotoxin contamination.

PubMed

Karlovsky, Petr; Suman, Michele; Berthiller, Franz; De Meester, Johan; Eisenbrand, Gerhard; Perrin, Irène; Oswald, Isabelle P; Speijers, Gerrit; Chiodini, Alessandro; Recker, Tobias; Dussort, Pierre

2016-11-01

Mycotoxins are fungal metabolites commonly occurring in food, which pose a health risk to the consumer. Maximum levels for major mycotoxins allowed in food have been established worldwide. Good agricultural practices, plant disease management, and adequate storage conditions limit mycotoxin levels in the food chain yet do not eliminate mycotoxins completely. Food processing can further reduce mycotoxin levels by physical removal and decontamination by chemical or enzymatic transformation of mycotoxins into less toxic products. Physical removal of mycotoxins is very efficient: manual sorting of grains, nuts, and fruits by farmers as well as automatic sorting by the industry significantly lowers the mean mycotoxin content. Further processing such as milling, steeping, and extrusion can also reduce mycotoxin content. Mycotoxins can be detoxified chemically by reacting with food components and technical aids; these reactions are facilitated by high temperature and alkaline or acidic conditions. Detoxification of mycotoxins can also be achieved enzymatically. Some enzymes able to transform mycotoxins naturally occur in food commodities or are produced during fermentation but more efficient detoxification can be achieved by deliberate introduction of purified enzymes. We recommend integrating evaluation of processing technologies for their impact on mycotoxins into risk management. Processing steps proven to mitigate mycotoxin contamination should be used whenever necessary. Development of detoxification technologies for high-risk commodities should be a priority for research. While physical techniques currently offer the most efficient post-harvest reduction of mycotoxin content in food, biotechnology possesses the largest potential for future developments.

3D Geospatial Models for Visualization and Analysis of Groundwater Contamination at a Nuclear Materials Processing Facility

NASA Astrophysics Data System (ADS)

Stirewalt, G. L.; Shepherd, J. C.

2003-12-01

Analysis of hydrostratigraphy and uranium and nitrate contamination in groundwater at a former nuclear materials processing facility in Oklahoma were undertaken employing 3-dimensional (3D) geospatial modeling software. Models constructed played an important role in the regulatory decision process of the U.S. Nuclear Regulatory Commission (NRC) because they enabled visualization of temporal variations in contaminant concentrations and plume geometry. Three aquifer systems occur at the site, comprised of water-bearing fractured shales separated by indurated sandstone aquitards. The uppermost terrace groundwater system (TGWS) aquifer is composed of terrace and alluvial deposits and a basal shale. The shallow groundwater system (SGWS) aquifer is made up of three shale units and two sandstones. It is separated from the overlying TGWS and underlying deep groundwater system (DGWS) aquifer by sandstone aquitards. Spills of nitric acid solutions containing uranium and radioactive decay products around the main processing building (MPB), leakage from storage ponds west of the MPB, and leaching of radioactive materials from discarded equipment and waste containers contaminated both the TGWS and SGWS aquifers during facility operation between 1970 and 1993. Constructing 3D geospatial property models for analysis of groundwater contamination at the site involved use of EarthVision (EV), a 3D geospatial modeling software developed by Dynamic Graphics, Inc. of Alameda, CA. A viable 3D geohydrologic framework model was initially constructed so property data could be spatially located relative to subsurface geohydrologic units. The framework model contained three hydrostratigraphic zones equivalent to the TGWS, SGWS, and DGWS aquifers in which groundwater samples were collected, separated by two sandstone aquitards. Groundwater data collected in the three aquifer systems since 1991 indicated high concentrations of uranium (>10,000 micrograms/liter) and nitrate (> 500 milligrams

A comparison between broiler chicken carcasses with and without visible faecal contamination during the slaughtering process on hazard identification of Salmonella spp.

PubMed

Jiménez, S M; Salsi, M S; Tiburzi, M C; Pirovani, M E

2002-01-01

A comparison of the prevalence of Salmonella in chicken carcasses with and without visible faecal contamination during commercial slaughter practice was made. The relationship between Enterobacteriaceae, coliform and Escherichia coli counts and Salmonella status was also evaluated to establish the likelihood of using these groups as 'index' organisms to predict the presence of pathogen. Samples were removed immediately after evisceration, after the inside-outside shower and after chilling from the processing line for microbiological analysis. Of the carcasses visibly uncontaminated with faeces after the evisceration step 20% harboured salmonellas and 20.8% of the visibly contaminated carcasses were positive for the pathogen. When E. coli, coliforms and Enterobacteriaceae were used as predictor variables the error rates ranged from 33.3 to 60% for both sample types. There was no indication that any of the groups of organisms analysed could predict the incidence of salmonellas on the samples studied. Positive results for the pathogen were obtained at every tested step of the slaughtering process regardless of whether or not faecal contamination was present. The present study demonstrated that carcasses not visibly contaminated with faeces carried Salmonella as well as the visibly contaminated carcasses.

The transfer of natural Rhodamine B contamination from raw paprika fruit to capsicum oleoresin during the extraction process.

PubMed

Wu, Naiying; Gao, Wei; Lian, Yunhe; Du, Jingjing; Tie, Xiaowei

2017-12-15

Occurrence of Rhodamine B (RhB) contamination in paprika caused by agricultural materials during the vegetation process has been reported. It may transfer during the process of active compounds extraction, and eventually exist in final products. Herein, the re-distribution of RhB during the extraction process was assessed in terms of RhB contents, as well as mass, color value and capsaicinoids yield of each process. Results revealed that natural RhB contamination at 0.55-1.11µg/kg originated from raw paprika fruit then transferred with the extraction proceeded. About 95.5% of RhB was found in red oleoresin. After separation of red oleoresin, 91.6% of RhB was remained in capsicum oleoresin, only 3.7% in paprika red. These results were consistent with total capsaicinoids recovery of each product. The RhB levels in edible capsicum oleoresin in our present study at 0.01-0.34µg/kg did not exceed the legal limits established by the European Union. Copyright © 2017 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.

The sequential use of washing and an electrochemical reduction process for the remediation of lead-contaminated soils.

PubMed

Demir, Aydeniz; Köleli, Nurcan

2013-01-01

A two-step method for the remediation of three different types of lead (Pb)-contaminated soil was evaluated. The first step included soil washing with ethylenediaminetetraacetic acid (EDTA) to remove Pb from soils. The washing experiments were performed with 0.05 M Na2EDTA at 1:10 soil to liquid ratio. Following the washing, Pb removal efficiency from soils ranged within 50-70%. After the soil washing process, Pb2+ ions in the washing solution were reduced electrochemically in a fixed-bed reactor. Lead removal efficiency with the electrochemical reduction at -2.0 V potential ranged within 57-76%. The overall results indicate that this two-step method is an environmentally-friendly and effective technology to remediate Pb-contaminated soils, as well as Pb-contaminated wastewater treatment due to the transformation of toxic Pb2+ ions into a non-hazardous metallic form (Pb(0)).

Electrolyte selection and microbial toxicity for electrochemical oxidative water treatment using a boron-doped diamond anode to support site specific contamination incident response.

PubMed

Phillips, Rebecca B; James, Ryan R; Magnuson, Matthew L

2018-04-01

Intentional and unintentional contamination incidents, such as terrorist attacks, natural disasters, and accidental spills, can result in large volumes of contaminated water. These waters may require pre-treatment before disposal and assurances that treated waters will not adversely impact biological processes at wastewater treatment facilities, or receiving waters. Based on recommendations of an industrial workgroup, this study addresses such concerns by studying electrochemical advanced oxidation process (EAOP) pre-treatment for contaminated waters, using a boron-doped diamond (BDD) anode, prior to discharge to wastewater treatment facilities. Reaction conditions were investigated, and microbial toxicity was assessed using the Microtox ® toxicity assay and the Nitrification Inhibition test. A range of contaminants were studied including herbicides, pesticides, pharmaceuticals and flame retardants. Resulting toxicities varied with supporting electrolyte from 5% to 92%, often increasing, indicating that microbial toxicity, in addition to parent compound degradation, should be monitored during treatment. These toxicity results are particularly novel because they systematically compare the microbial toxicity effects of a variety of supporting electrolytes, indicating some electrolytes may not be appropriate in certain applications. Further, these results are the first known report of the use of the Nitrification Inhibition test for this application. Overall, these results systematically demonstrate that anodic oxidation using the BDD anode is useful for addressing water contaminated with refractory organic contaminants, while minimizing impacts to wastewater plants or receiving waters accepting EAOP-treated effluent. The results of this study indicate nitrate can be a suitable electrolyte for incident response and, more importantly, serve as a baseline for site specific EAOP usage. Copyright © 2018 Elsevier Ltd. All rights reserved.

Contribution of treated wastewater to the contamination of recreational river areas with Cryptosporidium spp. and Giardia duodenalis.

PubMed

Castro-Hermida, José Antonio; García-Presedo, Ignacio; Almeida, André; González-Warleta, Marta; Correia Da Costa, José Manuel; Mezo, Mercedes

2008-07-01

Samples of the influent and final effluent from 12 wastewater treatment plants from Galicia (NW, Spain) were analyzed for the presence of Cryptosporidium spp. oocysts and Giardia duodenalis cysts. All of the plants discharge effluent to a hydrographic basin in which there are numerous recreational areas and fluvial beaches. The samples (25-50 liters) were collected in spring, summer, autumn and winter of 2007. A total of 96 samples were analyzed using techniques included in the US Environmental Protection Agency Method 1623. To identify the genotypes present, the following genes were amplified and sequenced: 18S SSU rRNA (Cryptosporidium spp.) and beta-giardina (G. duodenalis). Both parasites were detected in influent and effluent samples from all treatment plants (100%) throughout the year, and G. duodenalis always outnumbered Cryptosporidium spp. The mean concentration of G. duodenalis per liter of influent was significantly higher (P<0.05) than the mean concentration of Cryptosporidium spp. per liter of influent. The mean concentrations of parasites in influent samples ranged from 6 to 350 Cryptosporidium spp. oocysts per liter and from 89 to 8305 G. duodenalis cysts per liter. In final treated effluent, the mean concentration of parasites ranged from 2 to 390 Cryptosporidium spp. oocysts per liter and from 79 to 2469 G. duodenalis cysts per liter. The distribution of results per season revealed that in all plants, the highest number of (oo)cysts were detected in spring and summer. Cryptosporidium parvum, Cryptosporidium andersoni, Cryptosporidium hominis and assemblages A-I, A-II, E of G. duodenalis were detected. The risk of contamination of water courses by Cryptosporidium spp. and G. duodenalis is therefore considerable. It is important that wastewater treatment authorities reconsider the relevance of the levels of contamination by both parasites in wastewater, and develop adequate countermeasures.

UV irradiation and autoclave treatment for elimination of contaminating DNA from laboratory consumables.

PubMed

Gefrides, Lisa A; Powell, Mark C; Donley, Michael A; Kahn, Roger

2010-02-01

Laboratories employ various approaches to ensure that their consumables are free of DNA contamination. They may purchase pre-treated consumables, perform quality control checks prior to casework, and use in-house profile databases for contamination detection. It is better to prevent contamination prior to DNA typing than identify it after samples are processed. To this end, laboratories may UV irradiate or autoclave consumables prior to use but treatment procedures are typically based on killing microorganisms and not on the elimination of DNA. We report a systematic study of UV and autoclave treatments on the persistence of DNA from saliva. This study was undertaken to determine the best decontamination strategy for the removal of DNA from laboratory consumables. We have identified autoclave and UV irradiation procedures that can eliminate nanogram quantities of contaminating DNA contained within cellular material. Autoclaving is more effective than UV irradiation because it can eliminate short fragments of contaminating DNA more effectively. Lengthy autoclave or UV irradiation treatments are required. Depending on bulb power, a UV crosslinker may take a minimum of 2h to achieve an effective dose for elimination of nanogram quantities of contaminating DNA (>7250mJ/cm(2)). Similarly autoclaving may also take 2h to eliminate similar quantities of contaminating DNA. For this study, we used dried saliva stains to determine the effective dose. Dried saliva stains were chosen because purified DNA as well as fresh saliva are less difficult to eradicate than dried stains and also because consumable contamination is more likely to be in the form of a collection of dry cells.

Dynamic variation of bioactive compounds and aflatoxins in contaminated Radix Astragali during extraction process.

PubMed

Hu, Yichen; Kong, Weijun; Luo, Hongli; Zhao, Lianhua; Yang, Meihua

2016-03-30

Although increasing attention has been paid to the health threat caused by mycotoxins in commodities such as food or medicines, mycotoxin transfer processes from crude material to products have raised little concern so far. Radix Astragali is a commonly used edible and medicinal herbal plant that is susceptible to contamination with aflatoxins from Aspergillus flavus. There have been no studies on mycotoxin transfer into pharmaceutical preparations or derivative products. To facilitate the aflatoxin reduction and bioactivity retention, the dynamic variations of aflatoxins as well as herbal compounds, namely calycosin-7-glucoside, astragaloside and formononetin, in Radix Astragali contaminated by A. flavus during water decoction and ethanol refluxing treatments were evaluated simultaneously by an ultra-fast liquid chromatography-triple quadrupole linear ion trap mass spectrometry method. After the extraction processes, although the amount of alfatoxins was reduced remarkably, aflatoxin residuals in preparation still exceed recommended limits, manifesting the great need to establish a limit for aflatoxins in herbal extractions or derivative products. Meanwhile, due to the hydrolysis of glucoside, water decoction period should be no longer than 4 h. This investigation would benefit from the determination of the dynamic variation of aflatoxins in infected herbs in preparation treatments, in order to further develop aflatoxin limits in herbal preparations. © 2015 Society of Chemical Industry.

Remediation of lead-contaminated soils

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

Peters, R.W.; Shem, L.

1992-01-01

Excavation and transport of soil contaminated with heavy metals has generally been the standard remediation technique for treatment of heavy-metal-contaminated soils. This approach is not a permanent solution; moreover, off-site shipment and disposal of contaminated soil involves high expense, liability, and appropriate regulatory approval. Recently, a number of other techniques have been investigated for treating such contaminated sites, including flotation, solidification/stabilization, vitrification, and chemical extraction. This paper reports the results of a laboratory investigation determining the efficiency of using chelating agents to extract lead from contaminated soils. Lead concentrations in the soils ranged from 500 to 10,000 mg/kg. Ethylenediaminetetraacetic acidmore » (EDTA) and nitrilotriacetic acid (NTA) were examined for their potential extractive capabilities. Concentrations of the chelating agents ranged from 0.01 to 0.10 M. The pH of the suspensions in which the extractions were performed ranged from 4 to 12. Results showed that the removal of lead using NTA and water was ph-dependent, whereas the removal of lead using EDTA was ph-insensitive. Maximum removals of lead were 68.7%,19.1%, and 7.3% using EDTA, NTA, and water, respectively (as compared with initial lead concentrations).« less

Remediation of lead-contaminated soils

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

Peters, R.W.; Shem, L.

1992-09-01

Excavation and transport of soil contaminated with heavy metals has generally been the standard remediation technique for treatment of heavy-metal-contaminated soils. This approach is not a permanent solution; moreover, off-site shipment and disposal of contaminated soil involves high expense, liability, and appropriate regulatory approval. Recently, a number of other techniques have been investigated for treating such contaminated sites, including flotation, solidification/stabilization, vitrification, and chemical extraction. This paper reports the results of a laboratory investigation determining the efficiency of using chelating agents to extract lead from contaminated soils. Lead concentrations in the soils ranged from 500 to 10,000 mg/kg. Ethylenediaminetetraacetic acidmore » (EDTA) and nitrilotriacetic acid (NTA) were examined for their potential extractive capabilities. Concentrations of the chelating agents ranged from 0.01 to 0.10 M. The pH of the suspensions in which the extractions were performed ranged from 4 to 12. Results showed that the removal of lead using NTA and water was ph-dependent, whereas the removal of lead using EDTA was ph-insensitive. Maximum removals of lead were 68.7%,19.1%, and 7.3% using EDTA, NTA, and water, respectively (as compared with initial lead concentrations).« less

Heavy metal-immobilizing organoclay facilitates polycyclic aromatic hydrocarbon biodegradation in mixed-contaminated soil.

PubMed

Biswas, Bhabananda; Sarkar, Binoy; Mandal, Asit; Naidu, Ravi

2015-11-15

Soils contaminated with a mixture of heavy metals and polycyclic aromatic hydrocarbons (PAHs) pose toxic metal stress to native PAH-degrading microorganisms. Adsorbents such as clay and modified clay minerals can bind the metal and reduce its toxicity to microorganisms. However, in a mixed-contaminated soil, an adsorption process more specific to the metals without affecting the bioavailability of PAHs is desired for effective degradation. Furthermore, the adsorbent should enhance the viability of PAH-degrading microorganisms. A metal-immobilizing organoclay (Arquad(®) 2HT-75-bentonite treated with palmitic acid) (MIOC) able to reduce metal (cadmium (Cd)) toxicity and enhance PAH (phenanthrene) biodegradation was developed and characterized in this study. The MIOC differed considerably from the parent clay in terms of its ability to reduce metal toxicity (MIOC>unmodified bentonite>Arquad-bentonite). The MIOC variably increased the microbial count (10-43%) as well as activities (respiration 3-44%; enzymatic activities up to 68%), and simultaneously maintained phenanthrene in bioavailable form in a Cd-phenanthrene mixed-contaminated soil over a 21-day incubation period. This study may lead to a new MIOC-assisted bioremediation technique for PAHs in mixed-contaminated soils. Copyright © 2015 Elsevier B.V. All rights reserved.

Processes affecting geochemistry and contaminant movement in the middle Claiborne aquifer of the Mississippi embayment aquifer system

USGS Publications Warehouse

Katz, Brian G.; Kingsbury, James A.; Welch, Heather L.; Tollett, Roland W.

2012-01-01

Groundwater chemistry and tracer-based age data were used to assess contaminant movement and geochemical processes in the middle Claiborne aquifer (MCA) of the Mississippi embayment aquifer system. Water samples were collected from 30 drinking-water wells (mostly domestic and public supply) and analyzed for nutrients, major ions, pesticides, volatile organic compounds (VOCs), and transient age tracers (chlorofluorocarbons, tritium and helium-3, and sulfur hexafluoride). Redox conditions are highly variable throughout the MCA. However, mostly oxic groundwater with low dissolved solids is more vulnerable to nitrate contamination in the outcrop areas east of the Mississippi River in Mississippi and west Tennessee than in mostly anoxic groundwater in downgradient areas in western parts of the study area. Groundwater in the outcrop area was relatively young (apparent age of less than 40 years) with significantly (p 50 m depth) indicated contaminant movement from shallow parts of the aquifer into deeper oxic zones. Given the persistence of nitrate in young oxic groundwater that was recharged several decades ago, and the lack of a confining unit, the downward movement of young contaminated water may result in higher nitrate concentrations over time in deeper parts of the aquifer containing older oxic water.

Assessment of molecular contamination in mask pod

NASA Astrophysics Data System (ADS)

Foray, Jean Marie; Dejaune, Patrice; Sergent, Pierre; Gough, Stuart; Cheung, D.; Davenet, Magali; Favre, Arnaud; Rude, C.; Trautmann, T.; Tissier, Michel; Fontaine, H.; Veillerot, M.; Avary, K.; Hollein, I.; Lerit, R.

2008-04-01

Context/ study Motivation: Contamination and especially Airbone Molecular Contamination (AMC) is a critical issue for mask material flow with a severe and fairly unpredictable risk of induced contamination and damages especially for 193 nm lithography. It is therefore essential to measure, to understand and then try to reduce AMC in mask environment. Mask material flow was studied in a global approach by a pool of European partners, especially within the frame of European MEDEA+ project, so called "MUSCLE". This paper deals with results and assessment of mask pod environment in term of molecular contamination in a first step, then in a second step preliminary studies to reduce mask pod influence and contamination due to material out gassing. Approach and techniques: A specific assessment of environmental / molecular contamination along the supply chain was performed by all partners. After previous work presented at EMLC 07, further studies were performed on real time contamination measurement pod at different sites locations (including Mask manufacturing site, blank manufacturing sites, IC fab). Studies were linked to the main critical issues: cleaning, storage, handling, materials and processes. Contamination measurement campaigns were carried out along the mask supply chain using specific Adixen analyzer in order to monitor in real time organic contaminants (ppb level) in mask pods. Key results would be presented: VOC, AMC and humidity level on different kinds of mask carriers, impact of basic cleaning on pod outgassing measurement (VOC, NH3), and process influence on pod contamination... In a second step, preliminary specific pod conditioning studies for better pod environment were performed based on Adixen vacuum process. Process influence had been experimentally measured in term of molecular outgassing from mask pods. Different AMC experimental characterization methods had been carried out leading to results on a wide range of organic and inorganic

Process and system for treating waste water

DOEpatents

Olesen, Douglas E.; Shuckrow, Alan J.

1978-01-01

A process of treating raw or primary waste water using a powdered, activated carbon/aerated biological treatment system is disclosed. Effluent turbidities less than 2 JTU (Jackson turbidity units), zero TOC (total organic carbon) and in the range of 10 mg/l COD (chemical oxygen demand) can be obtained. An influent stream of raw or primary waste water is contacted with an acidified, powdered, activated carbon/alum mixture. Lime is then added to the slurry to raise the pH to about 7.0. A polyelectrolyte flocculant is added to the slurry followed by a flocculation period -- then sedimentation and filtration. The separated solids (sludge) are aerated in a stabilization sludge basin and a portion thereof recycled to an aerated contact basin for mixing with the influent waste water stream prior to or after contact of the influent stream with the powdered, activated carbon/alum mixture.

Influence de l'alteration physique sur les caracteristiques physico-chimiques de monolithes de sols contamines traites par stabilisation/solidification au ciment

NASA Astrophysics Data System (ADS)

Remillard, Jonathan

The concern of contaminated sites is affecting millions of property owner worldwide. As they pose a risk to the environment, human health or impair the value of buildings, remediation of contaminated sites has become an everyday issue. Stabilization/solidification (S/S) of contaminated soils with cement is a remediation technology that was developed to confine contaminants that cannot be degraded biologically, chemically or thermally by other technologies. Soils treated with S/S form a monolith that can be valorized on site. However, this practice is fairly uncommon in Quebec and this reluctance is partly due to the risks of degradation of the monoliths and the lack of knowledge relative to the long-term behavior of altered monoliths. The objective of this project was to simulate these degradations on cement-based monoliths of contaminated soils treated with S/S technology by causing physical alterations using different cycles of freeze/thawing and drying/wetting, and then to study the impact of these alterations on the mass losses, compressive strength, hydraulic conductivity, pH and leachability of five trace metals (Cd, Cr, Cu, Pb and Zn) used as contaminants. Various processes of S/S have been studied, either cement contents of 15 and 20%, then the presence of 5% by weight of calcium carbonate. For each S/S process formulated, the freeze/thaw cycles were much more effective in physically altering the monoliths. These alterations were mainly reflected by lower compressive strength, even more with lower cement contents. For their part, the drying/wetting cycles rather created a chemical change that lowered the pH of the monoliths. These chemical changes also affected the interpretation of leaching test results, especially for copper and zinc, since it was difficult to attribute effects to either physical or chemical alterations. The results showed that only chromium leached more clearly in response to physical alterations. All other elements studied were little

Efficacy of forming biofilms by Pseudomonas migulae AN-1 toward in situ bioremediation of aniline-contaminated aquifer by groundwater circulation wells.

PubMed

Zhao, Yongsheng; Qu, Dan; Zhou, Rui; Yang, Shuai; Ren, Hejun

2016-06-01

The formation and activity of aniline-degrading biofilms developed by the psychrotrophic Pseudomonas migulae AN-1 were studied for the in situ remediation of contaminated aquifer using in-well bioreactor of groundwater circulating wells (GCWs). Biofilms grown in mineral salt medium with aniline exhibited tolerance to high concentrations of aniline. In aniline degradation rate, AN-1 biofilms exhibited slight differences compared with planktonic cells. The effectiveness and bio-implication of AN-1 biofilms in GCWs were investigated to treat aniline-contaminated aquifer. The results demonstrate that AN-1 biofilms survived the GCWs treatment process with high aniline-degrading efficiency. This system provides a novel environmentally friendly technology for the in situ bioremediation of low-volatile contaminants.

Bioremediation of Petroleum and Radiological Contaminated Soils at the Savannah River Site: Laboratory to Field Scale Applications

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

BRIGMON, ROBINL.

In the process of Savannah River Site (SRS) operations limited amounts of waste are generated containing petroleum, and radiological contaminated soils. Currently, this combination of radiological and petroleum contaminated waste does not have an immediate disposal route and is being stored in low activity vaults. SRS developed and implemented a successful plan for clean up of the petroleum portion of the soils in situ using simple, inexpensive, bioreactor technology. Treatment in a bioreactor removes the petroleum contamination from the soil without spreading radiological contamination to the environment. This bioreactor uses the bioventing process and bioaugmentation or the addition of themore » select hydrocarbon degrading bacteria. Oxygen is usually the initial rate-limiting factor in the biodegradation of petroleum hydrocarbons. Using the bioventing process allowed control of the supply of nutrients and moisture based on petroleum contamination concentrations and soil type. The results of this work have proven to be a safe and cost-effective means of cleaning up low level radiological and petroleum-contaminated soil. Many of the other elements of the bioreactor design were developed or enhanced during the demonstration of a ''biopile'' to treat the soils beneath a Polish oil refinery's waste disposal lagoons. Aerobic microorganisms were isolated from the aged refinery's acidic sludge contaminated with polycyclic aromatic hydrocarbons (PAHs). Twelve hydrocarbon-degrading bacteria were isolated from the sludge. The predominant PAH degraders were tentatively identified as Achromobacter, Pseudomonas Burkholderia, and Sphingomonas spp. Several Ralstonia spp were also isolated that produce biosurfactants. Biosurfactants can enhance bioremediation by increasing the bioavailability of hydrophobic contaminants including hydrocarbons. The results indicated that the diversity of acid-tolerant PAH-degrading microorganisms in acidic oil wastes may be much greater than

Extraction of Profile Information from Cloud Contaminated Radiances. Appendixes 2

NASA Technical Reports Server (NTRS)

Smith, W. L.; Zhou, D. K.; Huang, H.-L.; Li, Jun; Liu, X.; Larar, A. M.

2003-01-01

Clouds act to reduce the signal level and may produce noise dependence on the complexity of the cloud properties and the manner in which they are treated in the profile retrieval process. There are essentially three ways to extract profile information from cloud contaminated radiances: (1) cloud-clearing using spatially adjacent cloud contaminated radiance measurements, (2) retrieval based upon the assumption of opaque cloud conditions, and (3) retrieval or radiance assimilation using a physically correct cloud radiative transfer model which accounts for the absorption and scattering of the radiance observed. Cloud clearing extracts the radiance arising from the clear air portion of partly clouded fields of view permitting soundings to the surface or the assimilation of radiances as in the clear field of view case. However, the accuracy of the clear air radiance signal depends upon the cloud height and optical property uniformity across the two fields of view used in the cloud clearing process. The assumption of opaque clouds within the field of view permits relatively accurate profiles to be retrieved down to near cloud top levels, the accuracy near the cloud top level being dependent upon the actual microphysical properties of the cloud. The use of a physically correct cloud radiative transfer model enables accurate retrievals down to cloud top levels and below semi-transparent cloud layers (e.g., cirrus). It should also be possible to assimilate cloudy radiances directly into the model given a physically correct cloud radiative transfer model using geometric and microphysical cloud parameters retrieved from the radiance spectra as initial cloud variables in the radiance assimilation process. This presentation reviews the above three ways to extract profile information from cloud contaminated radiances. NPOESS Airborne Sounder Testbed-Interferometer radiance spectra and Aqua satellite AIRS radiance spectra are used to illustrate how cloudy radiances can be used

Electromagnetic mixed waste processing system for asbestos decontamination

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

Kasevich, R.S.; Vaux, W.; Ulerich, N.

The overall objective of this three-phase program is to develop an integrated process for treating asbestos-containing material that is contaminated with radioactive and hazardous constituents. The integrated process will attempt to minimize processing and disposal costs. The objectives of Phase 1 were to establish the technical feasibility of asbestos decomposition, inorganic radionuclide nd heavy metal removal, and organic volatilization. Phase 1 resulted in the successful bench-scale demonstration of the elements required to develop a mixed waste treatment process for asbestos-containing material (ACM) contaminated with radioactive metals, heavy metals, and organics. Using the Phase 1 data, a conceptual process was developed.more » The Phase 2 program, currently in progress, is developing an integrated system design for ACM waste processing. The Phase 3 program will target demonstration of the mixed waste processing system at a DOE facility. The electromagnetic mixed waste processing system employs patented technologies to convert DOE asbestos to a non-hazardous, radionuclide-free, stable waste. The dry, contaminated asbestos is initially heated with radiofrequency energy to remove organic volatiles. Second,the radionuclides are removed by solvent extraction coupled with ion exchange solution treatment. Third, the ABCOV method converts the asbestos to an amorphous silica suspension at low temperature (100{degrees}C). Finally the amorphous silica is solidified for disposal.« less

Organic contaminant separator

DOEpatents

Del Mar, P.

1993-12-28

A process is presented of sample preparation prior to analysis for the concentration of an organic contaminant in an aqueous medium by (a) passing an initial aqueous medium including a minor amount of the organic contaminant through a composite tube comprised of a blend of a polyolefin and a polyester, the composite tube having an internal diameter of from about 0.1 to about 2.0 millimeters and being of sufficient length to permit the organic contaminant to adhere to the composite tube, (b) passing a solvent through the composite tube. The solvent is capable of separating the adhered organic contaminant from the composite tube. Further, an extraction apparatus is presented for sample preparation prior to analysis for the concentration of an organic contaminant in an aqueous medium. The apparatus includes a composite tube comprised of a blend of a polyolefin and a polyester. The composite tube has an internal diameter of from about 0.1 to about 2.0 millimeters and has sufficient length to permit an organic contaminant contained within an aqueous medium passed therethrough to adhere to the composite tube. 2 figures.

Whole-leaf wash improves chlorine efficacy for microbial reduction and prevents pathogen cross-contamination during fresh-cut lettuce processing.

PubMed

Nou, Xiangwu; Luo, Yaguang

2010-06-01

Currently, most fresh-cut processing facilities in the United States use chlorinated water or other sanitizer solutions for microbial reduction after lettuce is cut. Freshly cut lettuce releases significant amounts of organic matter that negatively impacts the effectiveness of chlorine or other sanitizers for microbial reduction. The objective of this study is to evaluate whether a sanitizer wash before cutting improves microbial reduction efficacy compared to a traditional postcutting sanitizer wash. Romaine lettuce leaves were quantitatively inoculated with E. coli O157:H7 strains and washed in chlorinated water before or after cutting, and E. coli O157:H7 cells that survived the washing process were enumerated to determine the effectiveness of microbial reduction for the 2 cutting and washing sequences. Whole-leaf washing in chlorinated water improved pathogen reduction by approximately 1 log unit over traditional cut-leaf sanitization. Similar improvement in the reduction of background microflora was also observed. Inoculated "Lollo Rossa" red lettuce leaves were mixed with noninoculated Green-Leaf lettuce leaves to evaluate pathogen cross-contamination during processing. High level (96.7% subsamples, average MPN 0.6 log CFU/g) of cross-contamination of noninoculated green leaves by inoculated red leaves was observed when mixed lettuce leaves were cut prior to washing in chlorinated water. In contrast, cross-contamination of noninoculated green leaves was significantly reduced (3.3% of subsamples, average MPN contamination prevention.

Regulatory and Technical Issues Concerning the Detection and Treatment of NDMA-Contaminated Groundwater at NASA WSTF

NASA Technical Reports Server (NTRS)

Wiebe, D. T.; Zigmond, M. J.; Tufts, C. A.

2002-01-01

The National Aeronautics and Space Administration (NASA) White Sands Test Facility (WSTF) was established in 1963 primarily to provide rocket engine testing services for several NASA programs. The groundwater underlying the site has been contaminated as a result of historical operations. Groundwater contaminants include several volatile organic compounds (VOCs) and two semi-volatile compounds: N-nitrosodimethylamine (NDMA) and N-nitrodimethylamine (DMN). This paper discusses some of the technical, analytical, regulatory, and health risk issues associated with the contaminant plume. The plume has moved approximately 2.5 miles downgradient of the facility industrial boundary, with evidence of continued migration. As a result, NASA has proposed a pump and treat system using air strippers and ultraviolet (UV) oxidation to stabilize future movement of the contaminant plume. The system has been designed to treat 1,076 gallons (4,073 liters) per minute, with provisions for future expansion. The UV oxidation process was selected to treat NDMA-contaminated groundwater based on successes at other NDMA-contaminated sites. Bench- and pilot-scale testing of WSTF groundwater confirmed the ability of UV oxidation to destroy NDMA and generated sufficient data to design the proposed full-scale treatment system. NDMA is acutely toxic and is a probable human carcinogen. EPA-recommended health risk criteria for the residential consumption of NDMA/DMN-contaminated groundwater was used to determine that a 1.0 x 10(exp -6) excess cancer risk corresponds to 1.7 parts per trillion (ppt). EPA analytical methods are unable to detect NDMA and DMN in the low ppt range. EPA's current Appendix IX analytical method used to screen for NDMA, Method 8270, can detect NDMA only at levels that are orders of magnitude greater than the recommended health risk level. Additionally, EPA Method 607, the most sensitive EPA approved method, has a detection limit of 150 ppt. This corresponds to an excess cancer

ENGINEERING ISSUE: TECHNOLOGY ALTERNATIVES FOR THE REMEDIATION OF PCB-CONTAMINATED SOIL AND SEDIMENT

EPA Science Inventory

Because of the increased need for Superfund decision-makers to have a working knowledge of the remedial capabilities available to treat soil and sediment contaminated with polychlorinated biphenyls (PCBs), the Superfund Engineering Forum has identified remediation of PCB-contamin...

Soil Contamination and Remediation Strategies. Current research and future challenge

NASA Astrophysics Data System (ADS)

Petruzzelli, G.

2012-04-01

Soil contamination: the heritage of industrial development Contamination is only a part of a whole set of soil degradation processes, but it is one of paramount importance since soil pollution greatly influences the quality of water, food and human health. Soil contamination has been identified as an important issue for action in the European strategy for soil protection, it has been estimated that 3.5 million of sites are potentially contaminated in Europe. Contaminated soils have been essentially discovered in industrial sites landfills and energy production plants, but accumulation of heavy metals and organic compounds can be found also in agricultural land . Remediation strategies. from incineration to bioremediation The assessment of soil contamination is followed by remedial action. The remediation of contaminated soils started using consolidates technologies (incineration inertization etc.) previously employed in waste treatment,. This has contributed to consider a contaminated soil as an hazardous waste. This rough approximation was unfortunately transferred in many legislations and on this basis soil knowledge have been used only marginally in the clean up procedures. For many years soil quality has been identified by a value of concentration of a contaminant and excavation and landfill disposal of soil has been largely used. In the last years the knowledge of remediation technology has rapidly grown, at present many treatment processes appear to be really feasible at field scale, and soil remediation is now based on risk assessment procedures. Innovative technologies, largely dependent on soil properties, such as in situ chemical oxidation, electroremediation, bioventing, soil vapor extraction etc. have been successfully applied. Hazardous organic compounds are commonly treated by biological technologies, biorememdiation and phytoremediation, being the last partially applied also for metals. Technologies selection is no longer exclusively based on

Prevention of Salmonella cross-contamination in an oilmeal manufacturing plant.

PubMed

Morita, T; Kitazawa, H; Iida, T; Kamata, S

2006-08-01

The mechanisms of Salmonella contamination in an oilmeal plant were investigated and the basic data were collected in order to achieve control of Salmonella in oilmeal. Salmonella was detected in all contamination vectors and environmental factors investigated, namely: operators, processing floor, dust in the air and rodents. In particular, high concentrations of Salmonella were detected on the processing floor of the manufacturing area, which has high oil content. Steam was the most effective disinfection method used for the processing floor, as the effects of heat sterilization and disinfection may work in tandem. In addition, restricting the movement of operators of the production chain remarkably reduced Salmonella contamination, even in areas of otherwise high contamination. Within the oilmeal plant, high Salmonella contamination rates for the processing floor represent the greatest risk of contamination of oilmeal via operators, dust in the air and rodents. Therefore, control of the processing floor is the most important means for reducing the oilmeal contamination rate. Specific Salmonella control methods for oilmeal plants have been established.

Analysis of therapeutic methods for treating vocal process granulomas.

PubMed

Ma, Lijing; Xiao, Yang; Ye, Jingying; Yang, Qingwen; Wang, Jun

2015-03-01

The combination of laryngeal microsurgery and local injections of botulinum toxin type A (BTA) can increase the cure rate of patients with vocal process granulomas (VPGs). To analyze the therapeutic effects of conservative treatments, microsurgical resection with suturing and microsurgery in combination with local injections of BTA for the treatment of VPGs. A retrospective analysis of 168 cases of VPG was performed. All of the patients initially received a conservative treatment. Some of the patients who did not respond to the conservative treatments were treated using microsurgical resection and microsuturing using an 8-0 absorbable filament. Other patients additionally received a four-point injection of BTA into the thyroarytenoid muscle and the arytenoid muscle on the operated side. The lesions of 41.3% (71/168) of the patients who were given the conservative treatments (including acid suppression, vocal rest, and voice therapy) disappeared, and the lesions of 10.7% (18/168) of the patients were reduced. The conservative treatments were unsuccessful for 47% (79/168) of the patients. The cure rate was 78.4% (29/37) for the patients who were treated by microscope resection using a CO2 laser and microsuturing of the surrounding mucosa. Of the eight patients who experienced a recurrence, five of them had lesions that disappeared after 3 months of conservative treatment, whereas the other three patients recovered after a second operation. The cure rate of the 42 patients who were treated using microsurgery combined with local injections of BTA was 95.2% (40/42), with only 2 cases of recurrence at 2 months post-treatment.

Isotopic constraints on contamination processes in the Tonian Goiás Stratiform Complex

NASA Astrophysics Data System (ADS)

Giovanardi, Tommaso; Mazzucchelli, Maurizio; Lugli, Federico; Girardi, Vicente A. V.; Correia, Ciro T.; Tassinari, Colombo C. G.; Cipriani, Anna

2018-06-01

The Tonian Goiás Stratiform Complex (TGSC, Goiás, central Brazil), is one of the largest mafic-ultramafic layered complexes in the world, emplaced during the geotectonic events that led to the Gondwana accretion. In this study, we present trace elements and in-situ U/Pb-Lu-Hf analyses of zircons and 87Sr/86Sr ratios of plagioclases from anorthosites and gabbros of the TGSC. Although formed by three isolated bodies (Cana Brava, Niquelândia and Barro Alto), and characterized by a Lower and Upper Sequence (LS and US), our new U/Pb zircon data confirm recent geochemical, geochronological, and structural evidences that the TGSC has originated from a single intrusive body in the Neoproterozoic. New Hf and Sr isotope ratios construe a complex contamination history for the TGSC, with different geochemical signatures in the two sequences. The low Hf and high Sr isotope ratios of the Lower Sequence (εHf(t) from -4.2 down to -27.5; 87Sr/86Sr = 0.706605-0.729226), suggest the presence of a crustal component and are consistent with contamination from meta-pelitic and calc-silicate rocks found as xenoliths within the Sequence. The more radiogenic Hf isotope ratios and low Sr isotope composition of the Upper Sequence (εHf(t) from 11.3 down to -8.4; 87Sr/86Sr = 0.702368-0.702452), suggest a contamination from mantle-derived metabasalts in agreement with the occurrences of amphibolite xenoliths in the US stratigraphy. The differential contamination of the two sequences is explained by the intrusion of the TGSC in a stratified crust dominated by metasedimentary rocks in its deeper part and metavolcanics at shallower levels. Moreover, the differential thermal gradient in the two crystallizing sequences might have contributed to the preservation and recrystallization of inherited zircon grains in the US and total dissolution or magmatic overgrowth of the LS zircons via melt/rock reaction processes.

ASSESSMENT OF STACHYBOTRYS REGROWTH ON CONTAMINATED WALLBOARD AFTER TREATMENT WITH COMMON SURFACE CLEANERS/DISINFECTANTS

EPA Science Inventory

The paper describes results of experiments assessing the efficacy of treating mold-contaminated gypsum wallboard with cleaners and/or disinfectants. Although the accepted recommendations for handling Stachybotrys chartarum contaminated gypsum wallboard are removal and replacement...

CHEMICAL ENHANCEMENTS TO PUMP-AND-TREAT REMEDIATION

EPA Science Inventory

Conventional pump-and-treat technologies are among the most widely used systems for the remediation of contaminated ground-water. ithin recent years it has become recognized that these systems can require protracted periods of time to make significant reductions in the quantity o...

Process for gamma ray induced degradation of polychlorinated biphenyls

DOEpatents

Meikrantz, D.H.; Mincher, B.J.; Arbon, R.E.

1998-08-25

The invention is a process for the in-situ destruction of polychlorinated biphenyl (PCB) compounds in transformer oils and transformers. These compounds are broken down selectively by irradiation of the object or mixture using spent nuclear fuel or any isotopic source of high energy gamma radiation. For example, the level of applied dose required to decompose 400 ppm of polychlorinated biphenyl in transformer oil to less than 50 ppm is 500 kilograms. Destruction of polychlorinated biphenyls to levels of less than 50 ppm renders the transformer oil or transformer non-PCB contaminated under current regulations. Therefore, this process can be used to treat PCB contaminated oil and equipment to minimize or eliminate the generation of PCB hazardous waste. 5 figs.

Characterization and Low-Cost Remediation of Soils Contaminated by Timbers in Community Gardens.

PubMed

Heiger-Bernays, W; Fraser, A; Burns, V; Diskin, K; Pierotti, D; Merchant-Borna, K; McClean, M; Brabander, D; Hynes, H P

2009-01-01

Urban community gardens worldwide provide significant health benefits to those gardening and consuming fresh produce from them. Urban gardens are most often placed in locations and on land in which soil contaminants reflect past practices and often contain elevated levels of metals and organic contaminants. Garden plot dividers made from either railroad ties or chromated copper arsenate (CCA) pressure treated lumber contribute to the soil contamination and provide a continuous source of contaminants. Elevated levels of polycyclic aromatic hydrocarbons (PAHs) derived from railroad ties and arsenic from CCA pressure treated lumber are present in the gardens studied. Using a representative garden, we 1) determined the nature and extent of urban community garden soil contaminated with PAHs and arsenic by garden timbers; 2) designed a remediation plan, based on our sampling results, with our community partner guided by public health criteria, local regulation, affordability, and replicability; 3) determined the safety and advisability of adding city compost to Boston community gardens as a soil amendment; and 4) made recommendations for community gardeners regarding healthful gardening practices. This is the first study of its kind that looks at contaminants other than lead in urban garden soil and that evaluates the effect on select soil contaminants of adding city compost to community garden soil.

Phytotreatment of soil contaminated with used lubricating oil using Hibiscus cannabinus.

PubMed

Abioye, O P; Agamuthu, P; Abdul Aziz, A R

2012-04-01

Soil contamination by hydrocarbons, especially by used lubricating oil, is a growing problem in developing countries, which poses a serious threat to the environment. Phytoremediation of these contaminated soils offers environmental friendly and a cost effective method for their remediation. Hibiscus cannabinus was studied for the remediation of soil contaminated with 2.5 and 1% used lubricating oil and treated with organic wastes [banana skin (BS), brewery spent grain (BSG) and spent mushroom compost (SMC)] for a period of 90 days under natural conditions. Loss of 86.4 and 91.8% used lubricating oil was recorded in soil contaminated with 2.5 and 1% oil and treated with organic wastes respectively at the end of 90 days. However, 52.5 and 58.9% oil loss was recorded in unamended soil contaminated with 2.5 and 1% oil, respectively. The plant did not accumulate hydrocarbon from the soil but shows appreciable accumulation of Fe and Zn in the root and stem of H. cannabinus at the end of the experiment. The first order kinetic rate of uptake of Fe and Zn in H. cannabinus was higher in organic wastes amendment treatments compared to the unamended treatments, which are extremely low. The results of this study suggest that H. cannabinus has a high potential for remediation of hydrocarbon and heavy metal contaminated soil.

Redistribution of fractions of zinc, cadmium, nickel, copper, and lead in contaminated calcareous soils treated with EDTA.

PubMed

Jalali, Mohsen; Khanlari, Zahra V

2007-11-01

Effect of ethylene diamine tetraacetic acid (EDTA) on the fractionation of zinc (Zn), cadmium (Cd), nickel (Ni), copper (Cu), and lead (Pb) in contaminated calcareous soils was investigated. Soil samples containing variable levels of contamination, from 105.9 to 5803 mg/kg Zn, from 2.2 to 1361 mg/kg Cd, from 31 to 64.0 mg/kg Ni, from 24 to 84 mg/kg Cu, and from 109 to 24,850 mg/kg Pb, were subjected to EDTA treatment at different dosages of 0, 1.0, and 2.0 g/kg. Metals in the incubated soils were fractionated after 5 months by a sequential extraction procedure, in which the metal fractions were experimentally defined as exchangeable (EXCH), carbonate (CARB), Mn oxide (MNO), Fe oxide (FEO), organic matter (OM), and residual (RES) fractions. In contaminated soils without EDTA addition, Zn, Ni, Cu, and Pb were predominately present in the RES fraction, up to 60.0%, 32.3%, 41.1%, and 36.8%, respectively. In general, with the EDTA addition, the EXCH and CARB fractions of these metals increased dramatically while the OM fraction decreased. The Zn, Ni, Cu, and Pb were distributed mostly in RES, OM, FEO, and CARB fractions in contaminated soils, but Cd was found predominately in the CARB, MNO, and RES fractions. The OM fraction decreased with increasing amounts of EDTA. In the contaminated soils, EDTA removed some Pb, Zn, Cu, and Ni from MNO, FEO, and OM fractions and redistributed them into CARB and EXCH fractions. Based on the relative percent in the EXCH and CARB fractions, the order of solubility was Cd > Pb > Ni > Cu > Zn for contaminated soils, before adding of EDTA, and after adding of EDTA, the order of solubility was Pb > Cd > Zn > Ni > Cu. The risk of groundwater contamination will increase after applying EDTA and it needed to be used very carefully.

Evaluation of the Effect of Silicone Contamination on Various Bond Systems and the Feasibility of Removing the Contamination

NASA Technical Reports Server (NTRS)

Stanley, Stephanie D.

2008-01-01

Silicone is a contaminant that can cause catastrophic failure of a bond system depending on the materials and processes used to fabricate the bond system, Unfortunately, more and more materials are fabricated using silicone. The purpose of this testing was to evaluate which bond systems are sensitive to silicone contamination and whether or not a cleaning process could be utilized to remove the silicone to bring the bond system performance back to baseline. Due to the extensive nature of the testing attempts will be made to generalize the understanding within classes of substrates, bond systems, and surface preparation and cleaning methods. This study was done by contaminating various meta! (steel, inconel, and aluminum), phenolic (carbon cloth phenolic and glass cloth phenolic), and rubber (natural rubber, asbestos-silicone dioxide filled natural butyldiene rubber, silica-filled ethylene propylenediene monomer, and carbon-filled ethylene propylenediene monomer) substrates which were then bonded using various adhesives and coatings (epoxy-based adhesives, paints, ablative compounds, and Chemlok adhesives) to determine the effect silicone contamination has on a given bond system's performance. The test configurations depended on the bond system being evaluated. The study also evaluated the feasibility of removing the silicone contamination by cleaning the contaminated substrate prior to bonding. The cleaning processes also varied depending on bond system.

Changes in iron, zinc and chelating agents during traditional African processing of maize: Effect of iron contamination on bioaccessibility.

PubMed

Greffeuille, Valérie; Polycarpe Kayodé, A P; Icard-Vernière, Christèle; Gnimadi, Muriel; Rochette, Isabelle; Mouquet-Rivier, Claire

2011-06-15

The effect of the different unit operations of processing traditionally used to produce four maize foods commonly consumed in Africa on the nutritional composition of the products was investigated, using Benin as a study context. The impact of the processes on lipid, fibre, phytate, iron and zinc contents varied with the process. The lowest IP6/Fe and IP6/Zn molar ratios, the indices used to assess Fe and Zn bioavailability were obtained in mawè, a fermented dough. Analysis of maize products highlighted a significant increase in iron content after milling, as a result of contamination by the equipment used. Evaluation of iron bioaccessibility by in vitro enzymatic digestion followed by dialysis revealed that the iron contamination, followed by lactic acid fermentation, led to a considerable increase in bioaccessible iron content. Extrinsic iron supplied to food products by the milling equipment could play a role in iron intake in developing countries. Copyright © 2010 Elsevier Ltd. All rights reserved.

Detection of microbial contamination during human islet isolation.

PubMed

Kin, Tatsuya; Rosichuk, Shawn; Shapiro, A M James; Lakey, Jonathan R T

2007-01-01

Current good manufacturing practice (cGMP) islet processing facilities provide an ultraclean environment for the safe production of clinical grade islets for transplantation into immunosuppressed diabetic recipients. The objective of this study was to monitor the rate of microbial contamination in islet products after implementation of good manufacturing practice conditions. Fluid samples for microbial contamination were collected at the following steps: from the pancreas transport solution upon arrival of the organ (n=157), after surface decontamination of the pancreas with antiseptic agents (n=89), from islet supernatant at the end of the isolation (n=104), and from islet supernatant as a final transplantable product after culture (n=53). Bacterial, fungal, and mycoplasma cultures were conducted for 2, 2, and 3 weeks, respectively. Microbial contamination was detected in 31% of transport solution. The contamination was not associated with the presence of the duodenum during the preservation, cold ischemia time, or procurement team (local vs. distant). Surface decontamination of the pancreas resulted in clearance of 92% of the microbial contamination. Six preparations at the end of the isolation revealed microbial growth. All were de novo contamination during the processing. Fifty-three preparations that met our release criteria in terms of product sterility were transplanted into type 1 diabetic patients. In two instances, positive culture of the islet preparation was reported after transplantation had occurred. No patient showed any clinical findings suggestive of infection or any radiological abnormalities suggestive of abscess; a single dose of antibiotic coverage was given routinely to recipients prior to islet infusion. Although transport solution carries a high risk of microbial contamination, most contaminants become undetectable during islet processing. Microbial contamination in final products is rare, but de novo contamination still occurs during

Detection of Microbial Contamination during Human Islet Isolation.

PubMed

Kin, Tatsuya; Rosichuk, Shawn; Shapiro, A M James; Lakey, Jonathan R T

2007-01-01

Current good manufacturing practice (cGMP) islet processing facilities provide an ultraclean environment for the safe production of clinical grade islets for transplantation into immunosuppressed diabetic recipients. The objective of this study was to monitor the rate of microbial contamination in islet products after implementation of good manufacturing practice conditions. Fluid samples for microbial contamination were collected at the following steps: from the pancreas transport solution upon arrival of the organ (n = 157), after surface decontamination of the pancreas with antiseptic agents (n = 89), from islet supernatant at the end of the isolation (n = 104), and from islet supernatant as a final transplantable product after culture (n = 53). Bacterial, fungal, and mycoplasma cultures were conducted for 2, 2, and 3 weeks, respectively. Microbial contamination was detected in 31% of transport solution. The contamination was not associated with the presence of the duodenum during the preservation, cold ischemia time, or procurement team (local vs. distant). Surface decontamination of the pancreas resulted in clearance of 92% of the microbial contamination. Six preparations at the end of the isolation revealed microbial growth. All were de novo contamination during the processing. Fifty-three preparations that met our release criteria in terms of product sterility were transplanted into type 1 diabetic patients. In two instances, positive culture of the islet preparation was reported after transplantation had occurred. No patient showed any clinical findings suggestive of infection or any radiological abnormalities suggestive of abscess; a single dose of antibiotic coverage was given routinely to recipients prior to islet infusion. Although transport solution carries a high risk of microbial contamination, most contaminants become undetectable during islet processing. Microbial contamination in final products is rare, but de novo contamination still occurs

Pathogenesis of Infection by Clinical and Environmental Strains of Vibrio vulnificus in Iron-Dextran-Treated Mice

PubMed Central

Starks, Angela M.; Schoeb, Trenton R.; Tamplin, Mark L.; Parveen, Salina; Doyle, Thomas J.; Bomeisl, Philip E.; Escudero, Gloria M.; Gulig, Paul A.

2000-01-01

Vibrio vulnificus is an opportunistic pathogen that contaminates oysters harvested from the Gulf of Mexico. In humans with compromising conditions, especially excess levels of iron in plasma and tissues, consumption of contaminated seafood or exposure of wounds to contaminated water can lead to systemic infection and disfiguring skin infection with extremely high mortality. V. vulnificus-associated diseases are noted for the rapid replication of the bacteria in host tissues, with extensive tissue damage. In this study we examined the virulence attributes of three virulent clinical strains and three attenuated oyster or seawater isolates in mouse models of systemic disease. All six V. vulnificus strains caused identical skin lesions in subcutaneously (s.c.) inoculated iron dextran-treated mice in terms of numbers of recovered CFU and histopathology; however, the inocula required for identical frequency and magnitude of infection were at least 350-fold higher for the environmental strains. At lethal doses, all strains caused s.c. skin lesions with extensive edema, necrosis of proximate host cells, vasodilation, and as many as 108 CFU/g, especially in perivascular regions. These data suggest that the differences between these clinical and environmental strains may be related to growth in the host or susceptibility to host defenses. In non-iron dextran-treated mice, strains required 105-fold-higher inocula to cause an identical disease process as with iron dextran treatment. These results demonstrate that s.c. inoculation of iron dextran-treated mice is a useful model for studying systemic disease caused by V. vulnificus. PMID:10992486

Processing-Dependent and Clonal Contamination Patterns of Listeria monocytogenes in the Cured Ham Food Chain Revealed by Genetic Analysis.

PubMed

Morganti, Marina; Scaltriti, Erika; Cozzolino, Paolo; Bolzoni, Luca; Casadei, Gabriele; Pierantoni, Marco; Foni, Emanuela; Pongolini, Stefano

2016-02-01

The quantitative and qualitative patterns of environmental contamination by Listeria monocytogenes were investigated in the production chain of dry-cured Parma ham. Standard arrays of surfaces were sampled in processing facilities during a single visit per plant in the three compartments of the food chain, i.e., ham production (19 plants) and postproduction, which was divided into deboning (43 plants) and slicing (25 plants) steps. The numbers of sampled surfaces were 384 in ham production, with 25 positive for L. monocytogenes, and 1,084 in postproduction, with 83 positives. Statistical analysis of the prevalence of contaminated surfaces showed that in ham production, contamination was higher at the beginning of processing and declined significantly toward the end, while in postproduction, prevalence rose toward the end of processing. Prevalence was higher in the deboning facilities than in slicing facilities and was dependent on the type of surface (floor/drainage > clothing > equipment). The qualitative pattern of contamination was investigated through an analysis of the survey isolates and a set of isolates derived from routine monitoring, including longitudinal isolations. Pulsed-field gel electrophoresis (PFGE) and whole-genome single-nucleotide polymorphism (SNP) analysis revealed a remarkable clonality of L. monocytogenes within plants, with the detection of 16 plant-specific clones out of 17 establishments with multiple isolates. Repeated detections of clonal isolates >6 months apart were also observed. Six was the maximum number of between-isolate differences in core SNPs observed within these clones. Based on the same six-SNP threshold, three clusters of clonal isolates, shared by six establishments, were also identified. The spread of L. monocytogenes within and between plants, as indicated by its clonal behavior, is a matter of concern for the hygienic management of establishments. Copyright © 2016, American Society for Microbiology. All Rights

Processing-Dependent and Clonal Contamination Patterns of Listeria monocytogenes in the Cured Ham Food Chain Revealed by Genetic Analysis

PubMed Central

Morganti, Marina; Scaltriti, Erika; Cozzolino, Paolo; Bolzoni, Luca; Casadei, Gabriele; Pierantoni, Marco; Foni, Emanuela

2015-01-01

The quantitative and qualitative patterns of environmental contamination by Listeria monocytogenes were investigated in the production chain of dry-cured Parma ham. Standard arrays of surfaces were sampled in processing facilities during a single visit per plant in the three compartments of the food chain, i.e., ham production (19 plants) and postproduction, which was divided into deboning (43 plants) and slicing (25 plants) steps. The numbers of sampled surfaces were 384 in ham production, with 25 positive for L. monocytogenes, and 1,084 in postproduction, with 83 positives. Statistical analysis of the prevalence of contaminated surfaces showed that in ham production, contamination was higher at the beginning of processing and declined significantly toward the end, while in postproduction, prevalence rose toward the end of processing. Prevalence was higher in the deboning facilities than in slicing facilities and was dependent on the type of surface (floor/drainage > clothing > equipment). The qualitative pattern of contamination was investigated through an analysis of the survey isolates and a set of isolates derived from routine monitoring, including longitudinal isolations. Pulsed-field gel electrophoresis (PFGE) and whole-genome single-nucleotide polymorphism (SNP) analysis revealed a remarkable clonality of L. monocytogenes within plants, with the detection of 16 plant-specific clones out of 17 establishments with multiple isolates. Repeated detections of clonal isolates >6 months apart were also observed. Six was the maximum number of between-isolate differences in core SNPs observed within these clones. Based on the same six-SNP threshold, three clusters of clonal isolates, shared by six establishments, were also identified. The spread of L. monocytogenes within and between plants, as indicated by its clonal behavior, is a matter of concern for the hygienic management of establishments. PMID:26590278

An OSEE Based Portable Surface Contamination Monitor

NASA Technical Reports Server (NTRS)

Perey, Daniel F.

1997-01-01

Many industrial and aerospace processes involving the joining of materials, require sufficient surface cleanliness to insure proper bonding. Processes as diverse as painting, welding, or the soldering of electronic circuits will be compromised if prior inspection and removal of surface contaminants is inadequate. As process requirements become more stringent and the number of different materials and identified contaminants increases, various instruments and techniques have been developed for improved inspection. One such technique based on the principle of Optically Stimulated Electron Emission (OSEE) has been explored for a number of years as a tool for surface contamination monitoring. Some of the benefits of OSEE are: it's non-contacting; requires little operator training; and has very high contamination sensitivity. This paper describes the development of a portable OSEE based surface contamination monitor. The instrument is suitable for both hand-held and robotic inspections with either manual or automated control of instrument operation. In addition, instrument output data is visually displayed to the operator and may be output to an external computer for archiving or analysis.

Nationwide reconnaissance of contaminants of emerging concern in source and treated drinking waters of the United States

EPA Science Inventory

When chemical or microbial contaminants are assessed for potential effect or possible regulation in ambient and drinking waters, a critical first step is determining if the contaminants occur and if they are at concentrations that may cause human or ecological health concerns. To...

Effective solidification/stabilisation of mercury-contaminated wastes using zeolites and chemically bonded phosphate ceramics.

PubMed

Zhang, Shaoqing; Zhang, Xinyan; Xiong, Ya; Wang, Guoping; Zheng, Na

2015-02-01

In this study, two kinds of zeolites materials (natural zeolite and thiol-functionalised zeolite) were added to the chemically bonded phosphate ceramic processes to treat mercury-contaminated wastes. Strong promotion effects of zeolites (natural zeolite and thiol-functionalised zeolite) on the stability of mercury in the wastes were obtained and these technologies showed promising advantages toward the traditional Portland cement process, i.e. using Portland cement as a solidification agent and natural or thiol-functionalised zeolite as a stabilisation agent. Not only is a high stabilisation efficiency (lowered the Toxicity Characteristic Leaching Procedure Hg by above 10%) obtained, but also a lower dosage of solidification (for thiol-functionalised zeolite as stabilisation agent, 0.5 g g(-1) and 0.7 g g(-1) for chemically bonded phosphate ceramic and Portland cement, respectively) and stabilisation agents (for natural zeolite as stabilisation agent, 0.35 g g(-1) and 0.4 g g(-1) for chemically bonded phosphate ceramic and Portland cement, respectively) were used compared with the Portland cement process. Treated by thiol-functionalised zeolite and chemically bonded phosphate ceramic under optimum parameters, the waste containing 1500 mg Hg kg(-1) passed the Toxicity Characteristic Leaching Procedure test. Moreover, stabilisation/solidification technology using natural zeolite and chemically bonded phosphate ceramic also passed the Toxicity Characteristic Leaching Procedure test (the mercury waste containing 625 mg Hg kg(-1)). Moreover, the presence of chloride and phosphate did not have a negative effect on the chemically bonded phosphate ceramic/thiol-functionalised zeolite treatment process; thus, showing potential for future application in treatment of 'difficult-to-manage' mercury-contaminated wastes or landfill disposal with high phosphate and chloride content. © The Author(s) 2015.

Vegetated Treatment Systems for Removing Contaminants Associated with Surface Water Toxicity in Agriculture and Urban Runoff.

PubMed

Anderson, Brian S; Phillips, Bryn M; Voorhees, Jennifer P; Cahn, Michael

2017-05-15

Urban stormwater and agriculture irrigation runoff contain a complex mixture of contaminants that are often toxic to adjacent receiving waters. Runoff may be treated with simple systems designed to promote sorption of contaminants to vegetation and soils and promote infiltration. Two example systems are described: a bioswale treatment system for urban stormwater treatment, and a vegetated drainage ditch for treating agriculture irrigation runoff. Both have similar attributes that reduce contaminant loading in runoff: vegetation that results in sorption of the contaminants to the soil and plant surfaces, and water infiltration. These systems may also include the integration of granulated activated carbon as a polishing step to remove residual contaminants. Implementation of these systems in agriculture and urban watersheds requires system monitoring to verify treatment efficacy. This includes chemical monitoring for specific contaminants responsible for toxicity. The current paper emphasizes monitoring of current use pesticides since these are responsible for surface water toxicity to aquatic invertebrates.

Preservative-treated wood and alternative products in the Forest Service

Treesearch

James (Scott) Groenier; Stan Lebow

2006-01-01

When treated wood is used in field settings, the possibility of environmental contamination raises concerns. There is increasing pressure to be environmentally friendly and to reduce, restrict, or eliminate the use of wood preservatives because of the concern that toxic constituents may leach from the treated wood. This report will provide an overview of preservative...

The ecological and physiological responses of the microbial community from a semiarid soil to hydrocarbon contamination and its bioremediation using compost amendment.

PubMed

Bastida, F; Jehmlich, N; Lima, K; Morris, B E L; Richnow, H H; Hernández, T; von Bergen, M; García, C

2016-03-01

The linkage between phylogenetic and functional processes may provide profound insights into the effects of hydrocarbon contamination and biodegradation processes in high-diversity environments. Here, the impacts of petroleum contamination and the bioremediation potential of compost amendment, as enhancer of the microbial activity in semiarid soils, were evaluated in a model experiment. The analysis of phospholipid fatty-acids (PLFAs) and metaproteomics allowed the study of biomass, phylogenetic and physiological responses of the microbial community in polluted semiarid soils. Petroleum pollution induced an increase of proteobacterial proteins during the contamination, while the relative abundance of Rhizobiales lowered in comparison to the non-contaminated soil. Despite only 0.55% of the metaproteome of the compost-treated soil was involved in biodegradation processes, the addition of compost promoted the removal of polycyclic aromatic hydrocarbons (PAHs) and alkanes up to 88% after 50 days. However, natural biodegradation of hydrocarbons was not significant in soils without compost. Compost-assisted bioremediation was mainly driven by Sphingomonadales and uncultured bacteria that showed an increased abundance of catabolic enzymes such as catechol 2,3-dioxygenases, cis-dihydrodiol dehydrogenase and 2-hydroxymuconic semialdehyde. For the first time, metaproteomics revealed the functional and phylogenetic relationships of petroleum contamination in soil and the microbial key players involved in the compost-assisted bioremediation. Copyright © 2015 Elsevier B.V. All rights reserved.

Comparison of the accident process, radioactivity release and ground contamination between Chernobyl and Fukushima-1

PubMed Central

Imanaka, Tetsuji; Hayashi, Gohei; Endo, Satoru

2015-01-01

In this report, we have reviewed the basic features of the accident processes and radioactivity releases that occurred in the Chernobyl accident (1986) and in the Fukushima-1 accident (2011). The Chernobyl accident was a power-surge accident that was caused by a failure of control of a fission chain reaction, which instantaneously destroyed the reactor and building, whereas the Fukushima-1 accident was a loss-of-coolant accident in which the reactor cores of three units were melted by decay heat after losing the electricity supply. Although the quantity of radioactive noble gases released from Fukushima-1 exceeded the amount released from Chernobyl, the size of land area severely contaminated by 137Cesium (137Cs) was 10 times smaller around Fukushima-1 compared with around Chernobyl. The differences in the accident process are reflected in the composition of the discharged radioactivity as well as in the composition of the ground contamination. Volatile radionuclides (such as 132Te-132I, 131I, 134Cs and 137Cs) contributed to the gamma-ray exposure from the ground contamination around Fukishima-1, whereas a greater variety of radionuclides contributed significantly around Chernobyl. When radioactivity deposition occurred, the radiation exposure rate near Chernobyl is estimated to have been 770 μGy h−1 per initial 137Cs deposition of 1000 kBq m−2, whereas it was 100 μGy h−1 around Fukushima-1. Estimates of the cumulative exposure for 30 years are 970 and 570 mGy per initial deposition of 1000 kBq m−2 for Chernobyl and Fukusima-1, respectively. Of these exposures, 49 and 98% were contributed by radiocesiums (134Cs + 137Cs) around Chernobyl and Fukushima-1, respectively. PMID:26568603

Comparison of the accident process, radioactivity release and ground contamination between Chernobyl and Fukushima-1.

PubMed

Imanaka, Tetsuji; Hayashi, Gohei; Endo, Satoru

2015-12-01

In this report, we have reviewed the basic features of the accident processes and radioactivity releases that occurred in the Chernobyl accident (1986) and in the Fukushima-1 accident (2011). The Chernobyl accident was a power-surge accident that was caused by a failure of control of a fission chain reaction, which instantaneously destroyed the reactor and building, whereas the Fukushima-1 accident was a loss-of-coolant accident in which the reactor cores of three units were melted by decay heat after losing the electricity supply. Although the quantity of radioactive noble gases released from Fukushima-1 exceeded the amount released from Chernobyl, the size of land area severely contaminated by (137)Cesium ((137)Cs) was 10 times smaller around Fukushima-1 compared with around Chernobyl. The differences in the accident process are reflected in the composition of the discharged radioactivity as well as in the composition of the ground contamination. Volatile radionuclides (such as (132)Te-(132)I, (131)I, (134)Cs and (137)Cs) contributed to the gamma-ray exposure from the ground contamination around Fukishima-1, whereas a greater variety of radionuclides contributed significantly around Chernobyl. When radioactivity deposition occurred, the radiation exposure rate near Chernobyl is estimated to have been 770 μGy h(-1) per initial (137)Cs deposition of 1000 kBq m(-2), whereas it was 100 μGy h(-1) around Fukushima-1. Estimates of the cumulative exposure for 30 years are 970 and 570 mGy per initial deposition of 1000 kBq m(-2) for Chernobyl and Fukusima-1, respectively. Of these exposures, 49 and 98% were contributed by radiocesiums ((134)Cs + (137)Cs) around Chernobyl and Fukushima-1, respectively. © The Author 2015. Published by Oxford University Press on behalf of The Japan Radiation Research Society and Japanese Society for Radiation Oncology.

Contaminated environments in the subsurface and bioremediation: organic contaminants.

PubMed

Holliger, C; Gaspard, S; Glod, G; Heijman, C; Schumacher, W; Schwarzenbach, R P; Vazquez, F

1997-07-01

Due to leakages, spills, improper disposal and accidents during transport, organic compounds have become subsurface contaminants that threaten important drinking water resources. One strategy to remediate such polluted subsurface environments is to make use of the degradative capacity of bacteria. It is often sufficient to supply the subsurface with nutrients such as nitrogen and phosphorus, and aerobic treatments are still dominating. However, anaerobic processes have advantages such as low biomass production and good electron acceptor availability, and they are sometimes the only possible solution. This review will focus on three important groups of environmental organic contaminants: hydrocarbons, chlorinated and nitroaromatic compounds. Whereas hydrocarbons are oxidized and completely mineralized under anaerobic conditions in the presence of electron acceptors such as nitrate, iron, sulfate and carbon dioxide, chlorinated and nitroaromatic compounds are reductively transformed. For the aerobic often persistent polychlorinated compounds, reductive dechlorination leads to harmless products or to compounds that are aerobically degradable. The nitroaromatic compounds are first reductively transformed to the corresponding amines and can subsequently be bound to the humic fraction in an aerobic process. Such new findings and developments give hope that in the near future contaminated aquifers can efficiently be remediated, a prerequisite for a sustainable use of the precious-subsurface drinking water resources.

Green Remediation Best Management Practices: Pump and Treat Technologies

EPA Pesticide Factsheets

The U.S. EPA Principles for Greener Cleanups outline the Agency's policy for evaluating and minimizing the environmental 'footprint' of activities undertaken when cleaning up a contaminated site with pump and treat technologies.

Study on contaminants on flight and other critical surfaces

NASA Technical Reports Server (NTRS)

Workman, Gary L.; Hughes, Charles; Arendale, William F.

1994-01-01

The control of surface contamination in the manufacture of space hardware can become a critical step in the production process. Bonded surfaces have been shown to be affected markedly by contamination. It is important to insure surface cleanliness by preventing contamination prior to bonding. In this vein techniques are needed in which the contamination which may affect bonding are easily found and removed. Likewise, if materials which are detrimental to bonding are not easily removed, then they should not be used in the manufacturing process. This study will address the development of techniques to locate and quantify contamination levels of particular contaminants. With other data becoming available from MSFC and its contractors, this study will also quantify how certain contaminants affect bondlines and how easily they are removed in manufacturing.

Terrestrial contamination in Apollo lunar samples.

NASA Technical Reports Server (NTRS)

Flory, D. A.; Simoneit, B. R.

1972-01-01

The contamination prevention procedures adopted for controlling the collection, processing, and analysis of the Apollo lunar samples in order to keep them free of significant levels of terrestrial organic matter are described. The organic contaminants actually found in the samples by the various investigators are summarized. It is shown that the program succeeded in providing investigators with samples containing less than 0.1 ppm total contamination.

Monitoring for contaminants of emerging concern in drinking water using POCIS passive samplers.

PubMed

Metcalfe, Chris; Hoque, M Ehsanul; Sultana, Tamanna; Murray, Craig; Helm, Paul; Kleywegt, Sonya

2014-03-01

Contaminants of emerging concern (CEC) have been detected in drinking water world-wide. The source of most of these compounds is generally attributed to contamination from municipal wastewater. Traditional water sampling methods (grab or composite) often require the concentration of large amounts of water in order to detect trace levels of these contaminants. The Polar Organic Compounds Integrative Sampler (POCIS) is a passive sampling technology that has been developed to concentrate trace levels of CEC to provide time-weighted average concentrations for individual compounds in water. However, few studies to date have evaluated whether POCIS is suitable for monitoring contaminants in drinking water. In this study, the POCIS was evaluated as a monitoring tool for CEC in drinking water over a period of 2 and 4 weeks with comparisons to typical grab samples. Seven "indicator compounds" which included carbamazepine, trimethoprim, sulfamethoxazole, ibuprofen, gemfibrozil, estrone and sucralose, were monitored in five drinking water treatment plants (DWTPs) in Ontario. All indicator compounds were detected in raw water samples from the POCIS in comparison to six from grab samples. Similarly, four compounds were detected in grab samples of treated drinking water, whereas six were detected in the POCIS. Sucralose was the only compound that was detected consistently at all five plants. The POCIS technique provided integrative exposures of CECs in drinking water at lower detection limits, while episodic events were captured via traditional sampling methods. There was evidence that the accumulation of target compounds by POCIS is a dynamic process, with adsorption and desorption on the sorbent occurring in response to ambient levels of the target compounds in water. CECs in treated drinking water were present at low ng L(-1) concentrations, which are not considered to be a threat to human health.

Assessment of exposures to fecally-contaminated recreational water

EPA Science Inventory

Exposure to fecally-contaminated recreational waters can pose a health risk to swimmers and other recreators. Since 2003, we have interviewed nearly 27,000 respondents at seven beaches impacted by treated sewage discharge. Information was collected about the duration and exposure...

Using slow-release permanganate candles to remediate PAH-contaminated water.

PubMed

Rauscher, Lindy; Sakulthaew, Chainarong; Comfort, Steve

2012-11-30

Surface waters impacted by urban runoff in metropolitan areas are becoming increasingly contaminated with polycyclic aromatic hydrocarbons (PAHs). Slow-release oxidant candles (paraffin-KMnO(4)) are a relatively new technology being used to treat contaminated groundwater and could potentially be used to treat urban runoff. Given that these candles only release permanganate when submerged, the ephemeral nature of runoff events would influence when the permanganate is released for treating PAHs. Our objective was to determine if slow-release permanganate candles could be used to degrade and mineralize PAHs. Batch experiments quantified PAH degradation rates in the presence of the oxidant candles. Results showed most of the 16 PAHs tested were degraded within 2-4 h. Using (14)C-labled phenanthrene and benzo(a)pyrene, we demonstrated that the wax matrix of the candle initially adsorbs the PAH, but then releases the PAH back into solution as transformed, more water soluble products. While permanganate was unable to mineralize the PAHs (i.e., convert to CO(2)), we found that the permanganate-treated PAHs were much more biodegradable in soil microcosms. To test the concept of using candles to treat PAHs in multiple runoff events, we used a flow-through system where urban runoff water was pumped over a miniature candle in repetitive wet-dry, 24-h cycles. Results showed that the candle was robust in removing PAHs by repeatedly releasing permanganate and degrading the PAHs. These results provide proof-of-concept that permanganate candles could potentially provide a low-cost, low-maintenance approach to remediating PAH-contaminated water. Copyright © 2012 Elsevier B.V. All rights reserved.

Disgust and Obsessive Beliefs in Contamination-related OCD

PubMed Central

Cisler, Josh M.; Brady, Robert E.; Olatunji, Bunmi O.; Lohr, Jeffrey M.

2010-01-01

A large body of evidence suggests that disgust is an important affective process underlying contamination fear. An independent line of research demonstrates that obsessive beliefs, particularly overestimations of threat, are also an important cognitive process underlying contamination fear. The present study attempts to integrate these two lines of research by testing whether obsessive beliefs potentiate the influence of disgust propensity on contamination fear. The interaction between disgust propensity and obsessive beliefs was tested in two large non-clinical samples (N = 252 in Study 1; N = 308 in Study 2) using two different self-report measures of contamination fear. Regression analyses supported the hypotheses in both samples. The interaction remained significant when controlling for negative affect. The results are hypothesized to suggest that contamination fear results, at least partly, from obsessive beliefs about the contamination-based appraisals that accompany heightened disgust responding. These results complement previous affective-driven explanations of the role of disgust in contamination fear by suggesting cognitive factors that similarly potentiate disgust’s role in contamination fear. PMID:20877585

Fuel quality/processing study. Volume 4: On site processing studies

NASA Technical Reports Server (NTRS)

Jones, G. E., Jr.; Cutrone, M.; Doering, H.; Hickey, J.

1981-01-01

Fuel treated at the turbine and the turbine exhaust gas processed at the turbine site are studied. Fuel treatments protect the turbine from contaminants or impurities either in the upgrading fuel as produced or picked up by the fuel during normal transportation. Exhaust gas treatments provide for the reduction of NOx and SOx to environmentally acceptable levels. The impact of fuel quality upon turbine maintenance and deterioration is considered. On site costs include not only the fuel treatment costs as such, but also incremental costs incurred by the turbine operator if a turbine fuel of low quality is not acceptably upgraded.

Evaluation of the Effect of Silicone Contamination on Various Bond Systems and the Feasibility of Removing the Contamination

NASA Technical Reports Server (NTRS)

Stanley, Stephanie D.

2008-01-01

Silicone is a contaminant that can cause catastrophic failure of a bond system depending on the materials and processes used to fabricate the bond system. Unfortunately, more and more materials are fabricated using silicone. The purpose of this testing was to evaluate which bond systems are sensitive to silicone contamination and whether or not a cleaning process could be utilized to remove the silicone to bring the bond system performance back to baseline. Due to the extensive nature of the testing, attempts will be made to generalize the understanding within classes of substrates, bond systems, and surface preparation and cleaning methods. This study was done by contaminating various metal (steel, Inconel, and aluminum), phenolic (carbon-cloth phenolic [CCP] and glass-cloth phenolic [GCP]), and rubber (natural rubber, asbestos-silicone dioxide filled natural butyldiene rubber [ASNBR]; silica-filled ethylene propylenediene monomer [SFEPDM], and carbon-filled ethylene propylenediene monomer [CFEPDM]) substrates which were then bonded using various adhesives and coatings (epoxy-based adhesives, paints, ablative compounds, and Chemlok adhesives) to determine the effect silicone contamination has on a given bond system's performance. The test configurations depended on the bond system being evaluated. The study also evaluated the feasibility of removing the silicone contamination by cleaning the contaminated substrate prior to bonding. The cleaning processes also varied depending on bond system.

Counter-current acid leaching process for copper azole treated wood waste.

PubMed

Janin, Amélie; Riche, Pauline; Blais, Jean-François; Mercier, Guy; Cooper, Paul; Morris, Paul

2012-09-01

This study explores the performance of a counter-current leaching process (CCLP) for copper extraction from copper azole treated wood waste for recycling of wood and copper. The leaching process uses three acid leaching steps with 0.1 M H2SO4 at 75degrees C and 15% slurry density followed by three rinses with water. Copper is recovered from the leachate using electrodeposition at 5 amperes (A) for 75 min. Ten counter-current remediation cycles were completed achieving > or = 94% copper extraction from the wood during the 10 cycles; 80-90% of the copper was recovered from the extract solution by electrodeposition. The counter-current leaching process reduced acid consumption by 86% and effluent discharge volume was 12 times lower compared with the same process without use of counter-current leaching. However, the reuse of leachates from one leaching step to another released dissolved organic carbon and caused its build-up in the early cycles.

Adsorption performance and mechanism of magnetic reduced graphene oxide in glyphosate contaminated water.

PubMed

Li, Yajuan; Zhao, Chuanqi; Wen, Yujuan; Wang, Yuanyuan; Yang, Yuesuo

2018-05-16

In this study, the magnetic reduced graphene oxide (RGO/Fe 3 O 4 ), with easy separation and high adsorption performance, was prepared and used to treat glyphosate (GLY) contaminated water. GLY adsorption performance of RGO/Fe 3 O 4 was investigated, and influences of pH, adsorption time, temperature, contaminant concentration, and competing anions were analyzed. Moreover, the adsorption mechanism was discussed in the light of several characterization methods, including scanning electron microscopy (SEM), energy dispersive spectrum (EDS), Fourier-transform infrared spectroscopy (FTIR), and X-ray photoelectron spectroscopy (XPS). The results demonstrated that the RGO/Fe 3 O 4 presented a significant GLY adsorption capacity and acid condition was beneficial for this adsorption. The pseudo-second-order kinetic model and the Langmuir model correlated satisfactorily to the experimental data, indicating that this process was controlled by chemical adsorption and monolayer adsorption. Thermodynamic studies revealed that the adsorption of glyphosate onto RGO/Fe 3 O 4 was spontaneous, endothermic, and feasible process. High temperatures were beneficial to GLY adsorption. The GLY adsorption mechanism of RGO/Fe 3 O 4 was mainly attributed to hydrogen-bond interaction, electrostatic interaction, and coordination. Therefore, the RGO/Fe 3 O 4 investigated in this research may offer an attractive adsorbent candidate for treatment of glyphosate contaminated water and warrant further study as a mechanism for glyphosate efficient removal.

Development of a Groundwater Transport Simulation Tool for Remedial Process Optimization

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

Ivarson, Kristine A.; Hanson, James P.; Tonkin, M.

2015-01-14

The groundwater remedy for hexavalent chromium at the Hanford Site includes operation of five large pump-and-treat systems along the Columbia River. The systems at the 100-HR-3 and 100-KR-4 groundwater operable units treat a total of about 9,840 liters per minute (2,600 gallons per minute) of groundwater to remove hexavalent chromium, and cover an area of nearly 26 square kilometers (10 square miles). The pump-and-treat systems result in large scale manipulation of groundwater flow direction, velocities, and most importantly, the contaminant plumes. Tracking of the plumes and predicting needed system modifications is part of the remedial process optimization, and is amore » continual process with the goal of reducing costs and shortening the timeframe to achieve the cleanup goals. While most of the initial system evaluations are conducted by assessing performance (e.g., reduction in contaminant concentration in groundwater and changes in inferred plume size), changes to the well field are often recommended. To determine the placement for new wells, well realignments, and modifications to pumping rates, it is important to be able to predict resultant plume changes. In smaller systems, it may be effective to make small scale changes periodically and adjust modifications based on groundwater monitoring results. Due to the expansive nature of the remediation systems at Hanford, however, additional tools were needed to predict the plume reactions to system changes. A computer simulation tool was developed to support pumping rate recommendations for optimization of large pump-and-treat groundwater remedy systems. This tool, called the Pumping Optimization Model, or POM, is based on a 1-layer derivation of a multi-layer contaminant transport model using MODFLOW and MT3D.« less

Performance Evaluations of Pump-and-Treat Remediations

EPA Pesticide Factsheets

Recent research has led to a better understanding of the complex chemical and physical processes controlling the movement of contaminants through the subsurface, and the ability to pump such contaminants...

Treatability assessment of polycyclic aromatic hydrocarbons contaminated marine sediments using permanganate, persulfate and Fenton oxidation processes.

PubMed

Shih, Yu-Jen; Binh, Nguyen Thanh; Chen, Chiu-Wen; Chen, Chih-Feng; Dong, Cheng-Di

2016-05-01

Various chemical oxidation techniques, such as potassium permanganate (KMnO4), sodium persulfate (Na2S2O8), Fenton (H2O2/Fe(2+)), and the modified persulfate and Fenton reagents (activated by ferrous complexes), were carried out to treat marine sediments that were contaminated with polycyclic aromatic hydrocarbons (PAHs) and dredged from Kaohsiung Harbor in Taiwan. Experimental results revealed that KMnO4 was the most effective of the tested oxidants in PAH degradation. Owing to the high organic matter content in the sediment that reduced the efficiencies of Na2S2O8 and regular Fenton reactions, a large excess of oxidant was required. Nevertheless, KH2PO4, Na4P2O7 and four chelating agents (EDTA, sodium citrate, oxalic acid, and sodium oxalate) were utilized to stabilize Fe(II) in activating the Na2S2O8 and Fenton oxidations, while Fe(II)-citrate remarkably promoted the PAH degradation. Increasing the molecular weight and number of rings of PAH did not affect the overall removal efficiencies. The correlation between the effectiveness of the oxidation processes and the physicochemical properties of individual PAH was statistically analyzed. The data implied that the reactivity of PAH (electron affinity and ionization potential) affected its treatability more than did its hydrophobicity (Kow, Koc and Sw), particularly using experimental conditions under which PAHs could be effectively oxidized. Copyright © 2016 Elsevier Ltd. All rights reserved.

Organic contaminant separator

DOEpatents

Mar, Peter D.

1994-01-01

A process of sample preparation prior to analysis for the concentration of an organic contaminant in an aqueous medium by (a) passing an initial aqueous medium including a minor amount of the organic contaminant through a composite tube including a polymeric base material selected from the group of polyolefins and polyfluorocarbons and particles of a carbon allotrope material adfixed to the inner wall of the polymeric base material, the composite tube having an internal diameter of from about 0.1 to about 2.0 millimeters and being of sufficient length to permit the organic contaminant to adhere to the composite tube, (b) passing a solvent through the composite tube, said solvent capable of separating the adhered organic contaminant from the composite tube. Further, an extraction apparatus for sample preparation prior to analysis for the concentration of an organic contaminant in an aqueous medium, said apparatus including a composite tube including a polymeric base material selected from the group of polyolefins and polyfluorocarbons and particles of a carbon allotrope material adfixed to the inner wall of the polymeric base material, the composite tube having an internal diameter of from about 0.1 to about 2.0 millimeters and being of sufficient length to permit an organic contaminant contained within an aqueous medium passed therethrough to adhere to the composite tube is disclosed.

Application of surrogates, indicators, and high-resolution mass spectrometry to evaluate the efficacy of UV processes for attenuation of emerging contaminants in water.

PubMed

Merel, Sylvain; Anumol, Tarun; Park, Minkyu; Snyder, Shane A

2015-01-23

In response to water scarcity, strategies relying on multiple processes to turn wastewater effluent into potable water are being increasingly considered by many cities. In such context, the occurrence of contaminants as well as their fate during treatment processes is a major concern. Three analytical approaches where used to characterize the efficacy of UV and UV/H2O2 processes on a secondary wastewater effluent. The first analytical approach assessed bulk organic parameters or surrogates before and after treatment, while the second analytical approach measured the removal of specific indicator compounds. Sixteen trace organic contaminants were selected due to their relative high concentration and detection frequency over eight monitoring campaigns. While their removal rate ranges from approximately 10 to >90%, some of these compounds can be used to gauge process efficacy (or failure). The third analytical approach assessed the fate of unknown contaminants through high-resolution time-of-flight (TOF) mass spectrometry with advanced data processing and demonstrated the occurrence of several thousand organic compounds in the water. A heat map clearly evidenced compounds as recalcitrant or transformed by the UV processes applied. In addition, those chemicals with similar fate were grouped together into clusters to identify new indicator compounds. In this manuscript, each approach is evaluated with advantages and disadvantages compared. Copyright © 2014 Elsevier B.V. All rights reserved.

Application of surrogates, indicators, and high-resolution mass spectrometry to evaluate the efficacy of UV processes for attenuation of emerging contaminants in water

PubMed Central

Merel, Sylvain; Anumol, Tarun; Park, Minkyu; Snyder, Shane A.

2016-01-01

In response to water scarcity, strategies relying on multiple processes to turn wastewater effluent into potable water are being increasingly considered by many cities. In such context, the occurrence of contaminants as well as their fate during treatment processes is a major concern. Three analytical approaches where used to characterize the efficacy of UV and UV/H2O2 processes on a secondary wastewater effluent. The first analytical approach assessed bulk organic parameters or surrogates before and after treatment, while the second analytical approach measured the removal of specific indicator compounds. Sixteen trace organic contaminants were selected due to their relative high concentration and detection frequency over eight monitoring campaigns. While their removal rate ranges from approximately 10 to >90%, some of these compounds can be used to gauge process efficacy (or failure). The third analytical approach assessed the fate of unknown contaminants through high-resolution time-of-flight (TOF) mass spectrometry with advanced data processing and demonstrated the occurrence of several thousand organic compounds in the water. A heat map clearly evidenced compounds as recalcitrant or transformed by the UV processes applied. In addition, those chemicals with similar fate were able to be grouped together into clusters to identify new indicator compounds. In this manuscript, each approach is evaluated with advantages and disadvantages compared. PMID:25262385

ADVANCED OXIDATION PROCESSES IN THE TREATMENT OF CONTAMINANT CANDIDATE LIST (CCL) COMPOUNDS

EPA Science Inventory

The current (2nd) Contaminant Candidate List was completed in 2005 by the United States EPA as an update to the Safe Drinking Water Act. The list of 42 chemical contaminants spans a wide array of classes, from pesticides to pharmaceuticals to elements, all of which are anticipate...

Rhinovirus inactivation by nasal tissues treated with virucide.

PubMed

Hayden, G F; Gwaltney, J M; Thacker, D F; Hendley, J O

1985-04-01

Rhinovirus colds may be transmitted by hand-to-hand contact followed by self-inoculation of nasal and/or conjunctival mucosa with virus contaminating the fingertips. The purpose of this study was to determine whether impregnation of nasal tissues with virucidal compounds could prevent rhinovirus from passing through the tissue and thus provide a means of preventing hand contamination during nose blowing. Paper tissues treated with a combination of citric acid, malic acid, and sodium laruryl sulfate were compared to placebo tissues containing sodium saccharin. Recovery of infectious virus was significantly reduced by passage of the virus-containing medium through virucidal versus placebo tissue (1/18 vs. 17/18 respectively, P less than 0.001, Fisher exact test). The virucidal effect of treated tissues was demonstrated for multiple rhinovirus serotypes suspended in either cell culture medium or nasal mucus. Virus contained in mucus from infected volunteers was also inactivated.

Preliminary screening of alternative technologies to incineration for treatment of chemical-agent-contaminated soil, Rocky Mountain Arsenal

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

Shem, L.M.; Rosenblatt, D.H.; Smits, M.P.

1995-12-01

In support of the U.S. Army`s efforts to determine the best technologies for remediation of soils, water, and structures contaminated with pesticides and chemical agents, Argonne National Laboratory has reviewed technologies for treating soils contaminated with mustard, lewisite, sarin, o-ethyl s-(2- (diisopropylamino)ethyl)methyl-phosphonothioate (VX), and their breakdown products. This report focuses on assessing alternatives to incineration for dealing with these contaminants. For each technology, a brief description is provided, its suitability and constraints on its use are identified, and its overall applicability for treating the agents of concern is summarized. Technologies that merit further investigation are identified.

Bioremediation of petroleum hydrocarbon-contaminated ground water: The perspectives of history and hydrology

USGS Publications Warehouse

Chapelle, F.H.

1999-01-01

Bioremediation, the use of microbial degradation processes to detoxify environmental contamination, was first applied to petroleum hydrocarbon-contaminated ground water systems in the early 1970s. Since that time, these technologies have evolved in some ways that were clearly anticipated early investigators, and in other ways that were not foreseen. The expectation that adding oxidants and nutrients to contaminated aquifers would enhance biodegradation, for example, has been born out subsequent experience. Many of the technologies now in common use such as air sparging, hydrogen peroxide addition, nitrate addition, and bioslurping, are conceptually similar to the first bioremediation systems put into operation. More unexpected, however, were the considerable technical problems associated with delivering oxidants and nutrients to heterogeneous ground water systems. Experience has shown that the success of engineered bioremediation systems depends largely on how effectively directions and rates of ground water flow can be controlled, and thus how efficiently oxidants and nutrients can be delivered to contaminated aquifer sediments. The early expectation that injecting laboratory-selected or genetically engineered cultures of hydrocarbon-degrading bacteria into aquifers would be a useful bioremediation technology has not been born out subsequent experience. Rather, it appears that petroleum hydrocarbon-degrading bacteria are ubiquitous in ground water systems and that bacterial addition is usually unnecessary. Perhaps the technology that was least anticipated early investigators was the development of intrinsic bioremediation. Experience has shown that natural attenuation mechanisms - biodegradation, dilution, and sorption - limit the migration of contaminants to some degree in all ground water systems. Intrinsic bioremediation is the deliberate use of natural attenuation processes to treat contaminated ground water to specified concentration levels at predetermined

Cryptosporidium-contaminated water disinfection by a novel Fenton process.

PubMed

Matavos-Aramyan, Sina; Moussavi, Mohsen; Matavos-Aramyan, Hedieh; Roozkhosh, Sara

2017-05-01

Three novel modified advanced oxidation process systems including ascorbic acid-, pro-oxidants- and ascorbic acid-pro-oxidants-modified Fenton system were utilized to study the disinfection efficiency on Cryptosporidium-contaminated drinking water samples. Different concentrations of divalent and trivalent iron ions, hydrogen peroxide, ascorbic acid and pro-oxidants at different exposure times were investigated. These novel systems were also compared to the classic Fenton system and to the control system which comprised of only hydrogen peroxide. The complete in vitro mechanism of the mentioned modified Fenton systems are also provided. The results pointed out that by considering the optimal parameter limitations, the ascorbic acid-modified Fenton system decreased the Cryptosporidium oocytes viability to 3.91%, while the pro-oxidant-modified and ascorbic acid-pro-oxidant-modified Fenton system achieved an oocytes viability equal to 1.66% and 0%, respectively. The efficiency of the classic Fenton at optimal condition was observed to be 20.12% of oocytes viability. The control system achieved 86.14% of oocytes viability. The optimum values of the operational parameters during this study are found to be 80mgL -1 for the divalent iron, 30mgL -1 for ascorbic acid, 30mmol for hydrogen peroxide, 25mgL -1 for pro-oxidants and an exposure time equal to 5min. The ascorbic acid-pro-oxidants-modified Fenton system achieved a promising complete water disinfection (0% viability) at the optimal conditions, leaving this method a feasible process for water disinfection or decontamination, even at industrial scales. Copyright © 2017 Elsevier Inc. All rights reserved.

An alternative process to treat boiler feed water for reuse.

PubMed

Guirgis, Adel; Ghosh, Jyoti P; Achari, Gopal; Langford, Cooper H; Banerjee, Daliya

2012-09-01

A bench-scale process to treat boiler feed water for reuse in steam generation was developed. Industrial water samples from a steam-assisted gravity drainage plant in northern Alberta, Canada, were obtained and samples characterized. The technology, which consists of coagulation-settling to remove oil/grease and particulates followed by an advanced oxidative treatment, led to clean water samples with negligible organic carbon. Coagulation followed by settling removed most particulates and some insoluble organics. The advanced oxidative treatment removed any remaining color in the samples, decreased the organic content to near-zero, and provided water ready for reuse.

Identification of pixels with stray light and cloud shadow contaminations in the satellite ocean color data processing.

PubMed

Jiang, Lide; Wang, Menghua

2013-09-20

A new flag/masking scheme has been developed for identifying stray light and cloud shadow pixels that significantly impact the quality of satellite-derived ocean color products. Various case studies have been carried out to evaluate the performance of the new cloud contamination flag/masking scheme on ocean color products derived from the Visible Infrared Imaging Radiometer Suite (VIIRS) onboard the Suomi National Polar-orbiting Partnership (SNPP). These include direct visual assessments, detailed quantitative case studies, objective statistic analyses, and global image examinations and comparisons. The National Oceanic and Atmospheric Administration (NOAA) Multisensor Level-1 to Level-2 (NOAA-MSL12) ocean color data processing system has been used in the study. The new stray light and cloud shadow identification method has been shown to outperform the current stray light flag in both valid data coverage and data quality of satellite-derived ocean color products. In addition, some cloud-related flags from the official VIIRS-SNPP data processing software, i.e., the Interface Data Processing System (IDPS), have been assessed. Although the data quality with the IDPS flags is comparable to that of the new flag implemented in the NOAA-MSL12 ocean color data processing system, the valid data coverage from the IDPS is significantly less than that from the NOAA-MSL12 using the new stray light and cloud shadow flag method. Thus, the IDPS flag/masking algorithms need to be refined and modified to reduce the pixel loss, e.g., the proposed new cloud contamination flag/masking can be implemented in IDPS VIIRS ocean color data processing.

Lead contamination of subarctic lakes and its response to reduced atmospheric fallout: can the recovery process be counteracted by the ongoing climate change?

PubMed

Klaminder, Jonatan; Hammarlund, Dan; Kokfelt, Ulla; Vonk, Jorien E; Bigler, Christian

2010-04-01

Can a climate-triggered export of old contaminants from the soil alter the lead (Pb) contaminant burden of subarctic lakes? To address this question, we reconstructed the pollution history of three high latitude lakes situated in a region where a recent climatic shift has occurred. Dated sediment records were used as archives of past Pb inputs to the lakes, where the difference in the (206)Pb/(207)Pb ratio between atmospheric contaminants ((206)Pb/(207)Pb ratio <1.16) and geogenic Pb in the catchment soil ((206)Pb/(207)Pb ratio >1.22) were used to trace fluxes of Pb contaminants. Lead contaminants were found in sediments deposited since Roman times. A significant export of Pb from the soil contaminant pool is indicated in two of the lakes surrounded by near-shore permafrost soils. Here, levels of Pb contaminants and (206)Pb/(207)Pb ratios of sediments deposited after the 1970s appear not to have been strongly affected by the >or=90% reduction in atmospheric deposition rates and increasing (206)Pb/(207)Pb ratios of atmospheric Pb since the 1990s. We concluded that soil processes stimulated by the ongoing climate change at high latitudes might work counteractive to efforts to reduce contaminant levels in subarctic lakes.

Combination of microbial oxidation and biogenic schwertmannite immobilization: A potential remediation for highly arsenic-contaminated soil.

PubMed

Yang, Zhihui; Wu, Zijian; Liao, Yingping; Liao, Qi; Yang, Weichun; Chai, Liyuan

2017-08-01

Here, a novel strategy that combines microbial oxidation by As(III)-oxidizing bacterium and biogenic schwertmannite (Bio-SCH) immobilization was first proposed and applied for treating the highly arsenic-contaminated soil. Brevibacterium sp. YZ-1 isolated from a highly As-contaminated soil was used to oxidize As(III) in contaminated soils. Under optimum culture condition for microbial oxidation, 92.3% of water-soluble As(III) and 84.4% of NaHCO 3 -extractable As(III) in soils were removed. Bio-SCH synthesized through the oxidation of ferrous sulfate by Acidithiobacillus ferrooxidans immobilize As(V) in the contaminated soil effectively. Consequently, the combination of microbial oxidation and Bio-SCH immobilization performed better in treating the highly As-contaminated soil with immobilization efficiencies of 99.3% and 82.6% for water-soluble and NaHCO 3 -extractable total As, respectively. Thus, the combination can be considered as a green remediation strategy for developing a novel and valuable solution for As-contaminated soils. Copyright © 2017 Elsevier Ltd. All rights reserved.

Response of microbial activities and diversity to PAHs contamination at coal tar contaminated land

NASA Astrophysics Data System (ADS)

Zhao, Xiaohui; Sun, Yujiao; Ding, Aizhong; Zhang, Dan; Zhang, Dayi

2015-04-01

Coal tar is one of the most hazardous and concerned organic pollutants and the main hazards are polycyclic aromatic hydrocarbons (PAHs). The indigenous microorganisms in soils are capable to degrade PAHs, with essential roles in biochemical process for PAHs natural attenuation. This study investigated 48 soil samples (from 8 depths of 6 boreholes) in Beijing coking and chemistry plant (China) and revealed the correlation between PAHs contamination, soil enzyme activities and microbial community structure, by 16S rRNA denaturing gradient gel electrophoresis (DGGE). At the site, the key contaminants were identified as naphthalene, acenaphthylene, acenaphthene, fluorene, phenanthrene and anthracene, and the total PAHs concentration ranged from 0.1 to 923.9 mg/kg dry soil. The total PAHs contamination level was positively correlated (p<0.05) with the bacteria count (0.9×107-14.2×107 CFU/mL), catalase activities (0.554-6.230 mL 0.02 M KMnO4/g•h) and dehydrogenase activities (1.9-30.4 TF μg/g•h soil), showing the significant response of microbial population and degrading functions to the organic contamination in soils. The PAHs contamination stimulated the PAHs degrading microbes and promoted their biochemical roles in situ. The positive relationship between bacteria count and dehydrogenase activities (p<0.05) suggested the dominancy of PAHs degrading bacteria in the microbial community. More interestingly, the microbial community deterioration was uncovered via the decline of microbial biodiversity (richness from 16S rRNA DGGE) against total PAHs concentration (p<0.05). Our research described the spatial profiles of PAHs contamination and soil microbial functions at the PAHs heavily contaminated sites, offering deeper understanding on the roles of indigenous microbial community in natural attenuation process.

Integration of Membrane Distillation with solar photo-Fenton for purification of water contaminated with Bacillus sp. and Clostridium sp. spores.

PubMed

Ruiz-Aguirre, A; Polo-López, M I; Fernández-Ibáñez, P; Zaragoza, G

2017-10-01

Although Membrane Distillation (MD) has been extensively studied for desalination, it has other applications like removing all kinds of solutes from water and concentrating non-volatile substances. MD offers the possibility of producing a clean stream while concentrating valuable compounds from waste streams towards their recovery, or emerging contaminants and pathogens present in wastewater in order to facilitate their chemical elimination. This paper analyses the elimination of bacterial spores from contaminated water with MD and the role of MD in the subsequent treatment of the concentrate with photo-Fenton process. The experiments were performed at Plataforma Solar de Almería (PSA) using a plate and frame bench module with a Permeate Gap Membrane Distillation (PGMD) configuration. Tests were done for two different kinds of spores in two different water matrixes: distilled water with 3.5wt% of sea salts contaminated with spores of Bacillus subtilis (B. subtilis) and wastewater after a secondary treatment and still contaminated with Clostridium sp. spores. An analysis of the permeate was performed in all cases to determine its purity, as well as the concentrated stream and its further treatment in order to assess the benefits of using MD. Results showed a permeate free of spores in all the cases, demonstrating the viability of MD to treat biological contaminated wastewater for further use in agriculture. Moreover, the results obtained after treating the concentrate with photo-Fenton showed a shorter treatment time for the reduction of the spore concentration in the water than that when only photo-Fenton was used. Copyright © 2017 Elsevier B.V. All rights reserved.

Remediating ethylbenzene-contaminated clayey soil by a surfactant-aided electrokinetic (SAEK) process.

PubMed

Yuan, Ching; Weng, Chih-Huang

2004-10-01

The objectives of this research are to investigate the remediation efficiency and electrokinetic behavior of ethylbenzene-contaminated clay by a surfactant-aided electrokinetic (SAEK) process under a potential gradient of 2 Vcm(-1). Experimental results indicated that the type of processing fluids played a key role in determining the removal performance of ethylbenzene from clay in the SAEK process. A mixed surfactant system consisted of 0.5% SDS and 2.0% PANNOX 110 showed the best performance of ethylbenzene removed in the SAEK system. The removal efficiency of ethylbenzene was determined to be 63-98% in SAEK system while only 40% was achieved in an electrokinetic system with tap water as processing fluid. It was found that ethylbenzene was accumulated in the vicinity of anode in an electrokinetic system with tap water as processing fluid. However, the concentration front of ethylbenzene was shifted toward cathode in the SAEK system. The electroosmotic permeability and power consumption were 0.17 x 10(-6)-3.01 x 10(-6) cm(2)V(-1)s(-1) and 52-123 kW h m(-3), respectively. The cost, including the expense of energy and surfactants, was estimated to be 5.15-12.65 USD m(-3) for SAEK systems, which was 2.0-4.9 times greater than that in the system of electrokinetic alone (2.6 USD m(-3)). Nevertheless, by taking the remediation efficiency of ethylbenzene and the energy expenditure into account for the overall process performance evaluation, the system SAEK was still a cost-effective alternative treatment method.

Development of a biotechnological process for the production of high quality linen fibers.

PubMed

Valladares Juárez, Ana Gabriela; Rost, Gernot; Heitmann, Uwe; Heger, Egon; Müller, Rudolf

2011-10-01

A novel biotechnological process for the production of high-quality flax fibers was developed. In this process, decorticated fibers from green flax were washed with 0.5% soda solution and treated with the pectinolytic strain Geobacillus thermoglucosidasius PB94A. Before drying the fibers, they were treated with the textile softener Adulcinol BUN. If the fibers contained contaminant shives, a bleaching step with hydrogen peroxide was performed before the softener treatment. In experiments where fibers were treated by the new process, and in which the bacterial solutions were reused seven times, the fiber quality was similar in all batches. The resolution of the treated fibers was 2.7 ± 0.4 and the fineness was 11.1 ± 1.1 dtex, while the starting material had a resolution of 7.3 and a fineness of 37 dtex. The new biotechnological treatment eliminates the weather-associated risks of the traditional fiber retting completely and produces consistently high-quality fibers that can be used to produce fine linen yarns.

EVALUATION OF BIOAEROSOL COMPONENTS, GENERATION FACTORS, AND AIRBORNE TRANSPORT ASSOCIATED WITH LIME TREATMENT OF CONTAMINATED SEDIMENT

EPA Science Inventory

Lime treatment has been used in contaminated sediment management activities for many purposes such as dewatering, improvement of physical properties, and reducing contaminant mobility. Exothermic volatilization of volatile organic compounds from lime-treated sediment is well kno...

Demonstration of the efficiency and robustness of an acid leaching process to remove metals from various CCA-treated wood samples.

PubMed

Coudert, Lucie; Blais, Jean-François; Mercier, Guy; Cooper, Paul; Janin, Amélie; Gastonguay, Louis

2014-01-01

In recent years, an efficient and economically attractive leaching process has been developed to remove metals from copper-based treated wood wastes. This study explored the applicability of this leaching process using chromated copper arsenate (CCA) treated wood samples with different initial metal loading and elapsed time between wood preservation treatment and remediation. The sulfuric acid leaching process resulted in the solubilization of more than 87% of the As, 70% of the Cr, and 76% of the Cu from CCA-chips and in the solubilization of more than 96% of the As, 78% of the Cr and 91% of the Cu from CCA-sawdust. The results showed that the performance of this leaching process might be influenced by the initial metal loading of the treated wood wastes and the elapsed time between preservation treatment and remediation. The effluents generated during the leaching steps were treated by precipitation-coagulation to satisfy the regulations for effluent discharge in municipal sewers. Precipitation using ferric chloride and sodium hydroxide was highly efficient, removing more than 99% of the As, Cr, and Cu. It appears that this leaching process can be successfully applied to remove metals from different CCA-treated wood samples and then from the effluents. Copyright © 2013 Elsevier Ltd. All rights reserved.

Numerical simulation of seasonal heat storage in a contaminated shallow aquifer - Temperature influence on flow, transport and reaction processes

NASA Astrophysics Data System (ADS)

Popp, Steffi; Beyer, Christof; Dahmke, Andreas; Bauer, Sebastian

2015-04-01

The energy market in Germany currently faces a rapid transition from nuclear power and fossil fuels towards an increased production of energy from renewable resources like wind or solar power. In this context, seasonal heat storage in the shallow subsurface is becoming more and more important, particularly in urban regions with high population densities and thus high energy and heat demand. Besides the effects of increased or decreased groundwater and sediment temperatures on local and large-scale groundwater flow, transport, geochemistry and microbiology, an influence on subsurface contaminations, which may be present in the urban surbsurface, can be expected. Currently, concerns about negative impacts of temperature changes on groundwater quality are the main barrier for the approval of heat storage at or close to contaminated sites. The possible impacts of heat storage on subsurface contamination, however, have not been investigated in detail yet. Therefore, this work investigates the effects of a shallow seasonal heat storage on subsurface groundwater flow, transport and reaction processes in the presence of an organic contamination using numerical scenario simulations. A shallow groundwater aquifer is assumed, which consists of Pleistoscene sandy sediments typical for Northern Germany. The seasonal heat storage in these scenarios is performed through arrays of borehole heat exchangers (BHE), where different setups with 6 and 72 BHE, and temperatures during storage between 2°C and 70°C are analyzed. The developing heat plume in the aquifer interacts with a residual phase of a trichloroethene (TCE) contamination. The plume of dissolved TCE emitted from this source zone is degraded by reductive dechlorination through microbes present in the aquifer, which degrade TCE under anaerobic redox conditions to the degradation products dichloroethene, vinyl chloride and ethene. The temperature dependence of the microbial degradation activity of each degradation step is

Treatment Processes for Removal of Wastewater Contaminants (WERF Report INFR8SG09)

EPA Science Inventory

This study investigated the nature of colloids associated with wastewater effluents. It also evaluated the association of emerging contaminants with these wastewater colloids. Two distinct emerging contaminants were investigated to gain general insight into the potential importan...

Biochar- and phosphate-induced immobilization of heavy metals in contaminated soil and water: implication on simultaneous remediation of contaminated soil and groundwater.

PubMed

Liang, Yuan; Cao, Xinde; Zhao, Ling; Arellano, Eduardo

2014-03-01

Long-term wastewater irrigation or solid waste disposal has resulted in the heavy metal contamination in both soil and groundwater. It is often separately implemented for remediation of contaminated soil or groundwater at a specific site. The main objective of this study was to demonstrate the hypothesis of simultaneous remediation of both heavy metal contaminated soil and groundwater by integrating the chemical immobilization and pump-and-treat methods. To accomplish the objective, three experiments were conducted, i.e., an incubation experiment was first conducted to determine how dairy-manure-derived biochar and phosphate rock tailing induced immobilization of Cd in the Cd-contaminated soils; second, a batch sorption experiment was carried out to determine whether the pre-amended contaminated soil still had the ability to retain Pb, Zn and Cd from aqueous solution. BCR sequential extraction as well as XRD and SEM analysis were conducted to explore the possible retention mechanism; and last, a laboratory-scale model test was undertaken by leaching the Pb, Zn, and Cd contaminated groundwater through the pre-amended contaminated soils to demonstrate how the heavy metals in both contaminated soil and groundwater were simultaneously retained and immobilized. The incubation experiment showed that the phosphate biochar were effective in immobilizing soil Cd with Cd concentration in TCLP (toxicity characteristics leaching procedure) extract reduced by 19.6 % and 13.7 %, respectively. The batch sorption experiment revealed that the pre-amended soil still had ability to retain Pb, Zn, and Cd from aqueous solution. The phosphate-induced metal retention was mainly due to the metal-phosphate precipitation, while both sorption and precipitation were responsible for the metal stabilization in the biochar amendment. The laboratory-scale test demonstrated that the soil amended with phosphate removed groundwater Pb, Zn, and Cd by 96.4 %, 44.6 %, and 49.2 %, respectively, and the

Optimization of electrocoagulation process to treat grey wastewater in batch mode using response surface methodology.

PubMed

Karichappan, Thirugnanasambandham; Venkatachalam, Sivakumar; Jeganathan, Prakash Maran

2014-01-10

Discharge of grey wastewater into the ecological system causes the negative impact effect on receiving water bodies. In this present study, electrocoagulation process (EC) was investigated to treat grey wastewater under different operating conditions such as initial pH (4-8), current density (10-30 mA/cm2), electrode distance (4-6 cm) and electrolysis time (5-25 min) by using stainless steel (SS) anode in batch mode. Four factors with five levels Box-Behnken response surface design (BBD) was employed to optimize and investigate the effect of process variables on the responses such as total solids (TS), chemical oxygen demand (COD) and fecal coliform (FC) removal. The process variables showed significant effect on the electrocoagulation treatment process. The results were analyzed by Pareto analysis of variance (ANOVA) and second order polynomial models were developed in order to study the electrocoagulation process statistically. The optimal operating conditions were found to be: initial pH of 7, current density of 20 mA/cm2, electrode distance of 5 cm and electrolysis time of 20 min. These results indicated that EC process can be scale up in large scale level to treat grey wastewater with high removal efficiency of TS, COD and FC.

Designer carbon nanotubes for contaminant removal in water and wastewater: A critical review.

PubMed

Sarkar, Binoy; Mandal, Sanchita; Tsang, Yiu Fai; Kumar, Pawan; Kim, Ki-Hyun; Ok, Yong Sik

2018-01-15

The search for effective materials for environmental cleanup is a scientific and technological issue of paramount importance. Among various materials, carbon nanotubes (CNTs) possess unique physicochemical, electrical, and mechanical properties that make them suitable for potential applications as environmental adsorbents, sensors, membranes, and catalysts. Depending on the intended application and the chemical nature of the target contaminants, CNTs can be designed through specific functionalization or modification processes. Designer CNTs can remarkably enhance contaminant removal efficiency and facilitate nanomaterial recovery and regeneration. An increasing number of CNT-based materials have been used to treat diverse organic, inorganic, and biological contaminants. These success stories demonstrate their strong potential in practical applications, including wastewater purification and desalination. However, CNT-based technologies have not been broadly accepted for commercial use due to their prohibitive cost and the complex interactions of CNTs with other abiotic and biotic environmental components. This paper presents a critical review of the existing literature on the interaction of various contaminants with CNTs in water and soil environments. The preparation methods of various designer CNTs (surface functionalized and/or modified) and the functional relationships between their physicochemical characteristics and environmental uses are discussed. This review will also help to identify the research gaps that must be addressed for enhancing the commercial acceptance of CNTs in the environmental remediation industry. Copyright © 2017 Elsevier B.V. All rights reserved.

Simultaneous application of chemical oxidation and extraction processes is effective at remediating soil Co-contaminated with petroleum and heavy metals.

PubMed

Yoo, Jong-Chan; Lee, Chadol; Lee, Jeung-Sun; Baek, Kitae

2017-01-15

Chemical extraction and oxidation processes to clean up heavy metals and hydrocarbon from soil have a higher remediation efficiency and take less time than other remediation processes. In batch extraction/oxidation process, 3% hydrogen peroxide (H 2 O 2 ) and 0.1 M ethylenediaminetetraacetic acid (EDTA) could remove approximately 70% of the petroleum and 60% of the Cu and Pb in the soil, respectively. In particular, petroleum was effectively oxidized by H 2 O 2 without addition of any catalysts through dissolution of Fe oxides in natural soils. Furthermore, heavy metals bound to Fe-Mn oxyhydroxides could be extracted by metal-EDTA as well as Fe-EDTA complexation due to the high affinity of EDTA for metals. However, the strong binding of Fe-EDTA inhibited the oxidation of petroleum in the extraction-oxidation sequential process because Fe was removed during the extraction process with EDTA. The oxidation-extraction sequential process did not significantly enhance the extraction of heavy metals from soil, because a small portion of heavy metals remained bound to organic matter. Overall, simultaneous application of oxidation and extraction processes resulted in highly efficient removal of both contaminants; this approach can be used to remove co-contaminants from soil in a short amount of time at a reasonable cost. Copyright © 2016 Elsevier Ltd. All rights reserved.

REMOVAL OF ORGANIC CCL CONTAMINANTS FROM DRINKING WATERS BY MEMBRANE AND GAC PROCESSES

EPA Science Inventory

Bench-scale treatment data for membrane and granular activated carbon technologies are presented for the organic contaminants on the U.S. Environmental Protection Agency's Contaminant Candidate List (CCL). For granular activated carbon (GAC), isotherm results are presented and q...

Delphi`s DETOXSM process: Preparing to treat high organic content hazardous and mixed wastes

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

Robertson, D.T.; Rogers, T.W.; Goldblatt, S.D.

1998-12-31

The US Department of Energy (DOE) Federal Energy Technology Center is sponsoring a full-scale technology demonstration of Delphi Research, Inc.`s patented DETOX{sup SM} catalytic wet chemical oxidation waste treatment process at the Savannah River Site (SRS) in South Carolina. The process is being developed primarily to treat hazardous and mixed wastes within the DOE complex as an alternative to incineration, but it has significant potential to treat wastes in the commercial sector. The results of the demonstration will be intensively studied and used to validate the technology. A critical objective in preparing for the demonstration was the successful completion ofmore » a programmatic Operational Readiness Review. Readiness Reviews are required by DOE for all new process startups. The Readiness Review provided the vehicle to ensure that Delphi was ready to start up and operate the DETOX{sup SM} process in the safest manner possible by implementing industry accepted management practices for safe operation. This paper provides an overview of the DETOX{sup SM} demonstration at SRS, and describes the crucial areas of the Readiness Review that marked the first steps in Delphi`s transition from a technology developer to an operating waste treatment services provider.« less

High hydrostatic pressure processing of murine norovirus 1-contaminated oysters inhibits oral infection in STAT-1 -/- deficient female mice

USDA-ARS?s Scientific Manuscript database

We have previously demonstrated that high pressure processing (HPP) is effective in preventing in vitro replication of murine norovirus strain 1 (MNV-1), a human norovirus surrogate, in a monocyte cell line following extraction from MNV-1-contaminated oysters. In the present study, the efficacy of ...

Performance of food safety management systems in poultry meat preparation processing plants in relation to Campylobacter spp. contamination.

PubMed

Sampers, Imca; Jacxsens, Liesbeth; Luning, Pieternel A; Marcelis, Willem J; Dumoulin, Ann; Uyttendaele, Mieke

2010-08-01

A diagnostic instrument comprising a combined assessment of core control and assurance activities and a microbial assessment instrument were used to measure the performance of current food safety management systems (FSMSs) of two poultry meat preparation companies. The high risk status of the company's contextual factors, i.e., starting from raw materials (poultry carcasses) with possible high numbers and prevalence of pathogens such as Campylobacter spp., requires advanced core control and assurance activities in the FSMS to guarantee food safety. The level of the core FSMS activities differed between the companies, and this difference was reflected in overall microbial quality (mesophilic aerobic count), presence of hygiene indicators (Enterobacteriaceae, Staphylococcus aureus, and Escherichia coli), and contamination with pathogens such as Salmonella, Listeria monocytogenes, and Campylobacter spp. The food safety output expressed as a microbial safety profile was related to the variability in the prevalence and contamination levels of Campylobacter spp. in poultry meat preparations found in a Belgian nationwide study. Although a poultry meat processing company could have an advanced FSMS in place and a good microbial profile (i.e., lower prevalence of pathogens, lower microbial numbers, and less variability in microbial contamination), these positive factors might not guarantee pathogen-free products. Contamination could be attributed to the inability to apply effective interventions to reduce or eliminate pathogens in the production chain of (raw) poultry meat preparations.

Reaction of the lateral periodontium of dogs' teeth to contaminated and noncontaminated perforations filled with mineral trioxide aggregate.

PubMed

Holland, Roberto; Bisco Ferreira, Luciana; de Souza, Valdir; Otoboni Filho, José Arlindo; Murata, Sueli Satomi; Dezan, Eloi

2007-10-01

It has been shown that the mineral trioxide aggregate (MTA) used to seal lateral/furcal perforations stimulates the deposition of newly formed cementum. Nevertheless, when the site of the perforation is contaminated, the healing process might occur under less favorable conditions. This study evaluated the repair healing process of noncontaminated and contaminated lateral perforations filled with MTA and the effect of previously filling the contaminated perforations with a bactericidal agent. Thirty lateral root perforations were prepared in endodontically treated dog's teeth, thus forming 3 groups with 10 specimens each. In group 1 the perforations were immediately sealed with MTA. In group 2 the perforations were left open for 7 days and thereafter sealed with MTA. In group 3 the perforations were left open for 7 days, filled temporarily with a calcium hydroxide-based paste for 14 days, and then sealed with MTA. The animals were killed after 90 days, and the pieces were prepared for histomorphologic and histomicrobiologic evaluations. The statistical analysis showed that group 1 had significantly better repair than groups 2 (P < .05) and 3 (P < .05), which validates the superior results obtained when MTA was immediately used to seal root perforations. Groups 2 and 3 had statistically similar repair to each other (P > .05). There were a larger number of cases of complete or partial biologic seal in group 1 compared with the contaminated groups. It might be concluded that the lateral root perforations sealed with MTA after contamination presented worse repair than the noncontaminated, immediately sealed perforations. The temporary filling with a bactericidal agent (calcium hydroxide-based paste) did not improve the repair of perforations exposed to contamination, and the contaminated groups presented similar results to each other.

INNOVATIVE IN-SITU REMEDIATION OF CONTAMINATED SEDIMENTS FOR SIMULTANEOUS CONTROL OF CONTAMINATION AND EROSION

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

Knox, A; Michael Paller, M; Danny D. Reible, D

2007-11-28

New technologies are needed that neutralize contaminant toxicity and control physical transport mechanisms that mobilize sediment contaminants. The last 12 months of this comprehensive project investigated the use of combinations of sequestering agents to develop in situ active sediment caps that stabilize mixtures of contaminants and act as a barrier to mechanical disturbance under a broad range of environmental conditions. Efforts focused on the selection of effective sequestering agents for use in active caps, the composition of active caps, and the effects of active cap components on contaminant bioavailability and retention. Results from this project showed that phosphate amendments, somemore » organoclays, and the biopolymer, chitosan, were very effective at removing metals from both fresh and salt water. These amendments also exhibited high retention (80% or more) of most metals indicating reduced potential for remobilization to the water column. Experiments on metal speciation and retention in contaminated sediment showed that apatite and organoclay can immobilize a broad range of metals under both reduced and oxidized conditions. These studies were followed by sequential extractions to evaluate the bioavailability and retention of metals in treated sediments. Metal fractions recovered in early extraction steps are more likely to be bioavailable and were termed the Potentially Mobile Fraction (PMF). Less bioavailable fractions collected in later extraction steps were termed the Recalcitrant Factor (RF). Apatite and organoclay reduced the PMF and increased the RF for several elements, especially Pb, Zn, Ni, Cr, and Cd. Empirically determined partitioning coefficients and modeling studies were used to assess the retention of organic contaminants on selected sequestering agents. Organoclays exhibited exceptionally high sorption of polycyclic aromatic hydrocarbons as indicated by a comparison of K{sub d} values among 12 amendments. These results suggested

Surfactant/Supercritical Fluid Cleaning of Contaminated Substrates

NASA Technical Reports Server (NTRS)

White, Gary L.

1997-01-01

CFC's and halogenated hydrocarbon solvents have been the solvents of choice to degrease and otherwise clean precision metal parts to allow proper function. Recent regulations have, however, rendered most of these solvents unacceptable for these purposes. New processes which are being used or which have been proposed to replace these solvents usually either fail to remove water soluble contaminants or produce significant aqueous wastes which must then be disposed of. In this work, a new method for cleaning surfaces will be investigated. Solubility of typical contaminants such as lubricating greases and phosphatizing bath residues will be studied in several surfactant/supercritical fluid solutions. The effect of temperature, pressure, and the composition of the cleaning mixture on the solubility of oily, polar, and ionic contaminants will be investigated. A reverse micellar solution in a supercritical light hydrocarbon solvent will be used to clean samples of industrial wastes. A reverse micellar solution is one where water is dissolved into a non-polar solvent with the aid of a surfactant. The solution will be capable of dissolving both water-soluble contaminants and oil soluble contaminants. Once the contaminants have been dissolved into the solution they will be separated from the light hydrocarbon and precipitated by a relatively small pressure drop and the supercritical solvent will be available for recycle for reuse. The process will be compared to the efficacy of supercritical CO2 cleaning by attempting to clean the same types of substrates and machining wastes with the same contaminants using supercritical CO2. It is anticipated that the supercritical CO2 process will not be capable of removing ionic residues.

Reclamation of cadmium-contaminated soil using dissolved organic matter solution originating from wine-processing waste sludge.

PubMed

Liu, Cheng-Chung; Chen, Guan-Bu

2013-01-15

Soil washing using an acid solution is a common practice for removing heavy metals from contaminated soil in Taiwan. However, serious loss of nutrients from soil is a major drawback of the washing. Distillery sludge can be used to prepare a dissolved organic matter (DOM) solution by extracting its organic constituents with alkaline solutions. This study employed DOM solutions to remediate Cd-contaminated soil (with concentrations up to 21.5 mg kg(-1)) and determine the factors affecting removal of Cd, such as pH, initial concentration of DOM solution, temperature, and washing frequency. When washing with pH 3.0 and 1250 mg L(-1) DOM solution, about 80% and 81% of Cd were removed from the topsoil at 27 °C and subsoil at 40 °C, respectively. To summarize the changes in fertility during DOM washing with various pH solutions: the increase in organic matter content ranged from 7.7% to 23.7%; cation exchange capacity (CEC) ranged from 4.6% to 13.9%; available ammonium (NNH(4)) content ranged from 39.4% to 2175%; and available phosphorus content ranged from 34.5% to 182%. Exchangeable K, Ca, and Mg remained in the topsoil after DOM washing, with concentrations of 1.1, 2.4, and 1.5 times higher than those treated with HCl solution at the same pH, respectively. Copyright © 2012 Elsevier B.V. All rights reserved.

Mild acid and alkali treated clay minerals enhance bioremediation of polycyclic aromatic hydrocarbons in long-term contaminated soil: A 14C-tracer study.

PubMed

Biswas, Bhabananda; Sarkar, Binoy; Rusmin, Ruhaida; Naidu, Ravi

2017-04-01

Bioremediation of polycyclic aromatic hydrocarbon (PAH)-contaminated soils requires a higher microbial viability and an increased PAH bioavailability. The clay/modified clay-modulated bacterial degradation could deliver a more efficient removal of PAHs in soils depending on the bioavailability of the compounds. In this study, we modified clay minerals (smectite and palygorskite) with mild acid (HCl) and alkali (NaOH) treatments (0.5-3 M), which increased the surface area and pore volume of the products, and removed the impurities without collapsing the crystalline structure of clay minerals. In soil incubation studies, supplements with the clay products increased bacterial growth in the order: 0.5 M HCl ≥ unmodified ≥ 0.5 M NaOH ≥ 3 M NaOH ≥ 3 M HCl for smectite, and 0.5 M HCl ≥ 3 M NaOH ≥ 0.5 M NaOH ≥ 3 M HCl ≥ unmodified for palygorskite. A 14 C-tracing study showed that the mild acid/alkali-treated clay products increased the PAH biodegradation (5-8%) in the order of 0.5 M HCl ≥ unmodified > 3 M NaOH ≥ 0.5 M NaOH for smectite, and 0.5 M HCl > 0.5 M NaOH ≥ unmodified ≥ 3 M NaOH for palygorskite. The biodegradation was correlated (r = 0.81) with the bioavailable fraction of PAHs and microbial growth as affected particularly by the 0.5 M HCl and 0.5 M NaOH-treated clay minerals. These results could be pivotal in developing a clay-modulated bioremediation technology for cleaning up PAH-contaminated soils and sediments in the field. Copyright © 2017 Elsevier Ltd. All rights reserved.

Development of an Integrated Multi-Contaminant Removal Process Applied to Warm Syngas Cleanup for Coal-Based Advanced Gasification Systems

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

Meyer, Howard

2010-11-30

This project met the objective to further the development of an integrated multi-contaminant removal process in which H2S, NH3, HCl and heavy metals including Hg, As, Se and Cd present in the coal-derived syngas can be removed to specified levels in a single/integrated process step. The process supports the mission and goals of the Department of Energy's Gasification Technologies Program, namely to enhance the performance of gasification systems, thus enabling U.S. industry to improve the competitiveness of gasification-based processes. The gasification program will reduce equipment costs, improve process environmental performance, and increase process reliability and flexibility. Two sulfur conversion conceptsmore » were tested in the laboratory under this project, i.e., the solventbased, high-pressure University of California Sulfur Recovery Process High Pressure (UCSRP-HP) and the catalytic-based, direct oxidation (DO) section of the CrystaSulf-DO process. Each process required a polishing unit to meet the ultra-clean sulfur content goals of <50 ppbv (parts per billion by volume) as may be necessary for fuel cells or chemical production applications. UCSRP-HP was also tested for the removal of trace, non-sulfur contaminants, including ammonia, hydrogen chloride, and heavy metals. A bench-scale unit was commissioned and limited testing was performed with simulated syngas. Aspen-Plus®-based computer simulation models were prepared and the economics of the UCSRP-HP and CrystaSulf-DO processes were evaluated for a nominal 500 MWe, coal-based, IGCC power plant with carbon capture. This report covers the progress on the UCSRP-HP technology development and the CrystaSulf-DO technology.« less

Method for treating beta-spodumene ceramics

DOEpatents

Day, J. Paul; Hickman, David L.

1994-09-27

A vapor-phase method for treating a beta-spodumene ceramic article to achieve a substitution of exchangeable hydrogen ions for the lithium present in the beta-spodumene crystals, wherein a barrier between the ceramic article and the source of exchangeable hydrogen ions is maintained in order to prevent lithium contamination of the hydrogen ion source and to generate highly recoverable lithium salts, is provided.