Sample records for abolina solvita jermacane

  1. Evaluation of Solvita compost stability and maturity tests for assessment of quality of end-products from mixed latrine style compost toilets

    SciTech Connect

    Hill, Geoffrey B., E-mail:; Baldwin, Susan A.; Vinnerås, Bjorn


    Highlights: • Solvita® stability and maturity tests used on composting toilet end-product. • Solvita® ammonia better suited in evaluation of feedstock suitability for vermicomposting. • No clear value of Solvita® stability test due to prevalent inhibition of decomposition by ammonia. - Abstract: It is challenging and expensive to monitor and test decentralized composting toilet systems, yet critical to prevent the mismanagement of potentially harmful and pathogenic end-product. Recent studies indicate that mixed latrine composting toilets can be inhibited by high ammonia content, a product of urea hydrolysis. Urine-diverting vermicomposting toilets are better able to accomplish the goals of remote sitemore » human waste management by facilitating the consumption of fecal matter by earthworms, which are highly sensitive to ammonia. The reliability of Solvita® compost stability and maturity tests were evaluated as a means of determining feedstock suitability for vermicomposting (ammonia) and end-product stability/completeness (carbon dioxide). A significant linear regression between Solvita® ammonia and free ammonia gas was found. Solvita® ranking of maturity did not correspond to ranking assigned by ammonium:nitrate standards. Solvita® ammonia values 4 and 5 contained ammonia levels below earthworm toxicity limits in 80% and 100% of samples respectively indicative of their use in evaluating feedstock suitability for vermicomposting. Solvita® stability tests did not correlate with carbon dioxide evolution tests nor ranking of stability by the same test, presumably due to in situ inhibition of decomposition and microbial respiration by ammonia which were reported by the Solvita® CO{sub 2} test as having high stability values.« less

  2. Recovery of microbial community structure and functioning after wildfire in semi-arid environments: optimising methods for monitoring and assessment

    NASA Astrophysics Data System (ADS)

    Muñoz-Rojas, Miriam; Martini, Dylan; Erickson, Todd; Merritt, David; Dixon, Kingsley


    Introduction In semi-arid areas such as northern Western Australia, wildfires are a natural part of the environment and many ecosystems in these landscapes have evolved and developed a strong relationship with fire. Soil microbial communities play a crucial role in ecosystem processes by regulating the cycling of nutrients via decomposition, mineralization, and immobilization processes. Thus, the structure (e.g. soil microbial biomass) and functioning (e.g. soil microbial activity) of microbial communities, as well as their changes after ecosystem disturbance, can be useful indicators of soil quality and health recovery. In this research, we assess the impacts of fire on soil microbial communities and their recovery in a biodiverse semi-arid environment of Western Australia (Pilbara region). New methods for determining soil microbial respiration as an indicator of microbial activity and soil health are also tested. Methodology Soil samples were collected from 10 similar ecosystems in the Pilbara with analogous native vegetation, but differing levels of post-fire disturbance (i.e. 3 months, 1 year, 5, 7 and 14 years after wildfire). Soil microbial activity was measured with the Solvita test which determines soil microbial respiration rate based on the measurement of the CO2 burst of a dry soil after it is moistened. Soils were dried and re-wetted and a CO2 probe was inserted before incubation at constant conditions of 25°C during 24 h. Measurements were taken with a digital mini spectrometer. Microbial (bacteria and fungi) biomass and community composition were measured by phospholipid fatty acid analysis (PLFA). Results Immediately after the fire (i.e. 3 months), soil microbial activity and microbial biomass are similar to 14 years 'undisturbed' levels (53.18±3.68 ppm CO2-CO and 14.07±0.65 mg kg-1, respectively). However, after the first year post-fire, with larger plant productivity, microbial biomass and microbial activity increase rapidly, peaking after 5

  3. Co-composting of livestock manure with rice straw: characterization and establishment of maturity evaluation system.


    Qian, Xiaoyong; Shen, Genxiang; Wang, Zhenqi; Guo, Chunxia; Liu, Yangqing; Lei, Zhongfang; Zhang, Zhenya


    Composting is considered to be a primary treatment method for livestock manure and rice straw, and high degree of maturity is a prerequisite for safe land application of the composting products. In this study pilot-scale experiments were carried out to characterize the co-composting process of livestock manure with rice straw, as well as to establish a maturity evaluation index system for the composts obtained. Two pilot composting piles with different feedstocks were conducted for 3 months: (1) swine manure and rice straw (SM-RS); and (2) dairy manure and rice straw (DM-RS). During the composting process, parameters including temperature, moisture, pH, total organic carbon (TOC), organic matter (OM), different forms of nitrogen (total, ammonia and nitrate), and humification index (humic acid and fulvic acid) were monitored in addition to germination index (GI), plant growth index (PGI) and Solvita maturity index. OM loss followed the first-order kinetic model in both piles, and a slightly faster OM mineralization was achieved in the SM-RS pile. Also, the SM-RS pile exhibited slightly better performance than the DM-RS according to the evolutions of temperature, OM degradation, GI and PGI. The C/N ratio, GI and PGI could be included in the maturity evaluation index system in which GI>120% and PGI>1.00 signal mature co-composts. Copyright © 2013 Elsevier Ltd. All rights reserved.

  4. High rate composting of herbal pharmaceutical industry solid waste.


    Ali, M; Duba, K S; Kalamdhad, A S; Bhatia, A; Khursheed, A; Kazmi, A A; Ahmed, N


    High rate composting studies of hard to degrade herbal wastes were conducted in a 3.5 m(3) capacity rotary drum composter. Studies were spread out in four trials: In trial 1 and 2, one and two turns per day rotation was observed, respectively, by mixing of herbal industry waste with cattle (buffalo) manure at a ratio of 3:1 on wet weight basis. In trial 3 inocula was added in raw waste to enhance the degradation and in trial 4 composting of a mixture of vegetable market waste and herbal waste was conducted at one turn per day. Results demonstrated that the operation of the rotary drum at one turn a day (trial 1) could provide the most conducive composting conditions and co-composting (trial 4) gave better quality compost in terms of temperature, moisture, nitrogen, and Solvita maturity index. In addition a FT-IR study also revealed that trial 1 and trial 4 gave quality compost in terms of stability and maturity due to the presence of more intense peaks in the aromatic region and less intense peaks were found in the aliphatic region compared with trial 2 and trial 3.

  5. Characterization of a soil amendment derived from co-composting of agricultural wastes and biochar

    NASA Astrophysics Data System (ADS)

    Curaqueo, Gustavo; Ángel Sánchez-Monedero, Miguel; Meier, Sebastián; Medina, Jorge; Panichini, Marcelo; Borie, Fernando; Navia, Rodrigo


    The aim of this study was to characterize a compost blend prepared from sheep manure and oat straw in a co-composting process enriched with oat husk biochar (BC). For this, a co-composting trial was carried out in rotatories bins of 200 L capacity. Three mixtures (piles) were assayed: BC0: sheep manure (SM) 65% w/w with 35% w/w oat straw (OS) and no biochar; BC5: SM 62.5% w/w, 32.5% of OS and 5% of BC and BC10: SM 60% w/w, 30% of OS and 10% of BC. The piles were turned 3 times per week in the first week, and then once a week until the end of the composting process (140 days). The temperature and humidity of the piles were monitored continually and the humidity was maintained in a range from 55% to 65%. The maturity of final compost was evaluated by FTIR and Solvita Test analysis. At the same time a chemical characterization including macro and micro nutrient for each compost was performed and the compost phytotoxic effect was evaluated by a germination test using aqueous extract over lettuce, radish and wheat seeds. FTIR analysis showed bands attributed to aromatic C=C, C=O stretching of amide groups, quinone C=O and/or C=O of H-bonded conjugated ketones (1640 cm-1) which are typical in biological stabilized composts and compost with high concentration of highly aromatic materials such as biochar, which seems to become relatively more intense specially in BC10 treatment. Both composts were characterized by a Solvita maturity index of 7, reflecting an adequate degree of maturation. The CO2 emission was lower in the piles enriched with BC compared to control treatment without BC. In the same way, NH3 index was 5 for all the treatments indicating a null NH3 emission. In this respect, a decrease in the N-NH4 content was related with the use of BC which indicate that BC could reduce N-losses during composting favoring nitrification process. Chemical characterization showed pH values higher than 8 for all piles and EC ranged from 8.6 to 14.7 dS cm-1. The Total N and P

  6. Benefits to decomposition rates when using digestate as compost co-feedstock: Part I - Focus on physicochemical parameters.


    Arab, Golnaz; McCartney, Daryl


    Anaerobic digestion (AD) has gained a significant role in municipal solid waste management, but managing a high volume of digestate is one of the challenges with AD technology. One option is to mix digestate with fresh and/or stabilized organic waste and then feed to the composting process. In this study, the effect of co-composting anaerobic digestate (in different quantities) on a composting process was investigated. The digestate was prepared in a pilot-scale 500L high solids dry anaerobic digester and composting was completed in eight 25L reactors with different ratios of digestate to fresh feedstock from the organic fraction of municipal solid waste (OFMSW). The digestate constituted 0, 10, 20, 30, 40, 50, 75, or 100% (wet mass) of the feedstock. The co-composting experiment was conducted in two phases: active aeration and curing. Monitored parameters included: process temperature, aeration rate, oxygen concentration of the outlet gas, mass changes, total solids, organic matter, pH, and electrical conductivity. In addition, respirometry, C:N ratio, ammonium to nitrate ratio, and Solvita® tests were used to quantify stability and maturity end points. The results showed that the addition of digestate to the OFMSW increased composting reaction rates in all cases, with peak performance occurring within the ratio of 20-40% of digestate addition on a wet weight basis. Reactor performance may have been influenced by the high total ammonia nitrogen (TAN) levels in the digestate. Composting rates increased as TAN levels increased up to 5000 TAN mgkg -1 DM; however, TAN may have become inhibitory at higher levels. Crown Copyright © 2017. Published by Elsevier Ltd. All rights reserved.