Composting as a solution to the increasing generation of municipal solid waste (MSW), also contribute to GHGs emission when not controlled and could lack some basic nutrients, especially nitrogen. This study assessed ...Composting as a solution to the increasing generation of municipal solid waste (MSW), also contribute to GHGs emission when not controlled and could lack some basic nutrients, especially nitrogen. This study assessed the split-additions of nitrogen-rich substrate to composting materials and their effect on GHGs emissions as well as the quality of the composts. Nitrogen-rich substrates formulated from pig and goat manure were co-composted with MSW for a 12-weeks period by split adding at mesophilic (˚C) and thermophilic (>50˚C) stages in five different treatments. Representative samples from the compost were taken from each treatment for physicochemical, heavy metals and bacteriological analysis. In-situ CH<sub>4</sub>, CO<sub>2</sub>, N<sub>2</sub>O gas emissions were also analyzed weekly during composting. It was observed that all the treatments showed significant organic matter decomposition, reaching thermophilic temperatures in the first week of composting. The absence affects the suitable agronomic properties. All nitrogen-rich substrate applied at thermophilic stage (Treatment two) recorded the highest N, P and K concentrations of 1.34%, 0.97% and 2.45%, respectively with highest nitrogen retention. In terms of GHG emissions, CO<sub>2</sub> was highest at the thermophilic stage when N-rich substrate was added in all treatment, while CH<sub>4</sub> was highest in the mesophilic stage with N-rich substrate addition. N<sub>2</sub>O showed no specific trend in the treatments. Split addition of the N-rich substrate for co-composting of MSW produced compost which is stable, has less nutrient loss and low GHG emissions. Split addition of a nitrogen-rich substrate could be an option for increasing the fertilizer value of MSW compost.展开更多
Pollution of arable land caused by heavy metals in livestock and poultry manure has become a potential threaten to human health in China.Safe disposal of the contained toxic pollution with animal manure by co-composti...Pollution of arable land caused by heavy metals in livestock and poultry manure has become a potential threaten to human health in China.Safe disposal of the contained toxic pollution with animal manure by co-composting with biochar is one of the alternative methods.Biochars from different sources(wheat straw,peanut shells and rice husks)amended with different loading rates were investigated for passivations of copper and zinc(Cu and Zn)in swine manure composting.Results showed that the passivation effects of the three types of biochar on Cu and Zn were enhanced with increasing biochar dose.Contents of Cu and Zn measured by diethylenetriaminepentaacetic acid(DTPA)and Community Bureau of Reference(CBR)showed that wheat straw biochar with the loading rates of 10%–13%(w/w)was superior to the other two types of biochar in this study.Compared with the control,sample from wheat straw biochar was more favorable for the bacterial growth of Proteobacteria,Firmicutes and Actinobacteria.In addition,pot experiment showed that organic fertilizer amended with wheat straw biochar could significantly improve the growth of Chinese pakchoi and enzyme activities(superoxide dismutase,peroxidase,polyphenol oxidase and catalase)as compared with the control.Cu and Zn contents of Chinese pakchoi in the organic fertilizer group containing wheat straw biochar reduced by 73.2%and 45.2%,65.8%and 33.6%,respectively,compared with the group without loading biochar.There was no significant difference in the contents of vitamin C and reducing sugar between the groups of organic fertilizer amended with/without wheat straw biochar,however,there was significant difference compared with the heavy metal addition group.The application of organic fertilizer formed by adding biochar can effectively reduce the adverse effects of heavy metals on crops.展开更多
Composting is now suggested as one of the environmentally and friendly alternative method for disposal of solid organic wastes, as it leads to minimization, stabilization, and utilization of organic waste. Transformat...Composting is now suggested as one of the environmentally and friendly alternative method for disposal of solid organic wastes, as it leads to minimization, stabilization, and utilization of organic waste. Transformations of nitrogen were investigated in co composting of pig manure with different amendments, such as sawdust and leaves. Samples were analyzed for pH, total N, soluble NH 4 N, soluble NO 3 N and soluble organic N. The total N increased after 63 days of composting, as well as the soluble NO 3 N and soluble organic N. Soluble NH 4 N increased significantly and showed peak values at day 7, thereafter decreased sharply and gradually to lower levels. Seed germination index (GI) showed that co composting of pig manure with sawdust reached maturity after 49 days of composting, while co composting of pig manure with sawdust and leaves required shorter time for 35 days. Soluble NH 4 N was significantly negatively ( P <0.05), while soluble NO 3 N and soluble organic N were significantly positively ( P <0.05), correlated with seed germination index (GI). Addition of leaves in co composting of pig manure with sawdust had no significant impacts on nitrogen transformations, but it was beneficial for maturity of pig manure compost.展开更多
Available information on the microbial mechanisms associated with heavy metal(HM)passivation during co-composting amended with phosphate rock(PR)remains limited.Thus,this study investigated the dynamic changes in bact...Available information on the microbial mechanisms associated with heavy metal(HM)passivation during co-composting amended with phosphate rock(PR)remains limited.Thus,this study investigated the dynamic changes in bacterial communities and HM-fractions(Zn,Cu,Cd,Cr and Pb)during swine manure composting with maize straw,and ascertained the bacterial influence on HM-passivation.The results demonstrated that the addition of PR improved HM-passivation,especially for Zn and Cd,with their bioavailability factors(BFs)reduced by 247.41 and 176.25%,respectively.As for bacterial communities,the proportion of Firmicutes decreased,while the proportions of Proteobacteria,Bacteroidetes,DeinococcusThermus and Gemmatimonadetes increased in all treatments.PR significantly changed the primary bacterial phyla in the thermophilic phase.Bacteroidetes were the main bacterial component controlling the passivation of Zn,Cu and Cr,while Deinococcus-Thermus mainly regulated the mobility of Zn and Pb,and Proteobacteria only dominated the transformation among Cd-fractions.These results may provide a reference for the use of HM-passivation techniques during composting.展开更多
Effects of the heavy metal copper(Cu), the metalloid arsenic(As), and the antibiotic oxytetracycline(OTC) on bacterial community structure and diversity during cow and pig manure composting were investigated. Eight tr...Effects of the heavy metal copper(Cu), the metalloid arsenic(As), and the antibiotic oxytetracycline(OTC) on bacterial community structure and diversity during cow and pig manure composting were investigated. Eight treatments were applied, four to each manure type, namely cow manure with:(1) no additives(control),(2) addition of heavy metal and metalloid,(3) addition of OTC and(4) addition of OTC with heavy metal and metalloid;and pig manure with:(5) no additives(control),(6) addition of heavy metal and metalloid,(7) addition of OTC and(8) addition of OTC with heavy metal and metalloid. After 35 days of composting, according to the alpha diversity indices, the combination treatment(OTC with heavy metal and metalloid) in pig manure was less harmful to microbial diversity than the control or heavy metal and metalloid treatments. In cow manure, the treatment with heavy metal and metalloid was the most harmful to the microbial community, followed by the combination and OTC treatments. The OTC and combination treatments had negative effects on the relative abundance of microbes in cow manure composts. The dominant phyla in both manure composts included Actinobacteria, Bacteroidetes, Firmicutes, and Proteobacteria. The microbial diversity relative abundance transformation was dependent on the composting time. Redundancy analysis(RDA) revealed that environmental parameters had the most influence on the bacterial communities. In conclusion, the composting process is the most sustainable technology for reducing heavy metal and metalloid impacts and antibiotic contamination in cow and pig manure. The physicochemical property variations in the manures had a significant effect on the microbial community during the composting process. This study provides an improved understanding of bacterial community composition and its changes during the composting process.展开更多
Oxytetracycline(OTC)residues have been found in soil and water,and they may pose potential risks to agricultural ecological environments.One of the most impactful ways for OTC to enter the soil and water environments ...Oxytetracycline(OTC)residues have been found in soil and water,and they may pose potential risks to agricultural ecological environments.One of the most impactful ways for OTC to enter the soil and water environments is through excrement used as organic fertilizer.Therefore,it is important to remove OTC during manure composting and to understand the transformation of the organic materials during composting in the presence of OTC.In the present paper,chicken manure and wheat sawdust spiked with OTC were composted under different initial moisture contents(MC)to evaluate the degradation of OTC and changes of organic matter during the composting process.The MC has a significant effect on OTC degradation during composting.A higher MC of 65% was more conducive to OTC degradation(77.4%)and compost maturity compared to the lower MC.However,the higher MC of 65%could increase the ammonia volatilization by promoting nitrification compared to the lower MC.An increase in the initial MC could improve the composting temperature.NMR results illustrated that the presence of OTC could affect the internal transformation of aliphatics,and OTC inhibited compost humification.Thus,an initial MC of 55–65% can alleviate the impacts of OTC on humification during manure composting.展开更多
Actinomycetes are known to produce an extensive range of bioactive compounds as well as variety of enzymes having multiple biotechnological applications. They are an important source of lignocellulose hydrolyzing enzy...Actinomycetes are known to produce an extensive range of bioactive compounds as well as variety of enzymes having multiple biotechnological applications. They are an important source of lignocellulose hydrolyzing enzymes and constitute considerable proportion of the soil or aquatic micro-flora responsible for degradation of biomass in natural environment. Presently, most of the commercially exploited lignocellulases and commercial biodegradation processes rely mostly on fungal or bacterial micro-organisms. Actinomycetes are relatively less explored for biodegradation processes that utilize lignocellulases for solid agro-waste management and waste water treatment. There is also a need to search and explore novel actinomycete strains for various biodegradation applications. This study involved examining the possibility of using only potent actinomycetes strains for the composting process by creating the consortium of such strains that could produce thermo-tolerant and alkali-tolerant key enzymes necessary for the degradation of cellulose, hemi-cellulose and lignin. The newly developed actinomycete consortium was tested for the composting activity and the composting process was optimized. The analysis of the composted material generated under ideal condition, demonstrated desirable physical and chemical characteristics. Paper pulp effluent poses a hazard to waterways due to toxicity. The toxicity of this mill effluent can be attributed to a compound called lignin and its chlorinated derivatives that are let out during the treatment of lignocellulosic constituents. Current study also involves the use of a strain of actinomycete having ability to produce enzyme laccase, which is active under alkaline condition for the treatment of paper pulp effluent. Enzyme laccase is known for its ability to attack phenolic components of lignin and common hazardous component of effluent, polycyclic aromatic hydrocarbons (PAH). Aerobic treatment of effluent by actinomycete strain indicated 21% reduction in COD at pH 7.5 after 14 days under optimum condition. This strain was identified as Streptomyces rochei based on molecular fingerprinting and was reported to be the producer of laccase probably for the first time. LCMS analysis of the treated effluent sample showed the presence of degradation compounds forming after 7 and 14 days of treatment. These compounds showed the degradation of lignin components and other phenolic, non-phenolic components of the effluent by intra molecular re-arrangement, oxidation and ring opening reactions. Overall, potent thermo-tolerant and alkali-tolerant actinomycete strains were successfully isolated and applied for bio-degradation of domestic agro-waste by composting and treatment of pulp-paper mill effluent. The consortium of these strains may be further utilized for scale-up studies in order to assess its commercial feasibility for biodegradation processes.展开更多
The evolution of metal species during sludge composting in aerobic reactor has been widely investigated,but little is known in large scale.In this study,the transformations of heavy metals speciation(Zn,Cu,Pb and Cd)i...The evolution of metal species during sludge composting in aerobic reactor has been widely investigated,but little is known in large scale.In this study,the transformations of heavy metals speciation(Zn,Cu,Pb and Cd)in the process of sludge composting were studied in a bunker.Physico-chemical parameters,such as pH,moisture content(MC),organic matter(OM),humic acids(HA)and fulvic acids(FA)contents,were determined to evaluate their impacts on the redistribution of Zn,Cu,Pb and Cd in sludge compost.During the composting process,the contents of Cu,Pb,Zn and Cd in oxidizable and residual forms increased,whereas the contents of the exchangeable Cu,Pb,Zn and Cd decreased,with a slight increase in the total heavy metal contents.The contents of Cu,Zn and Cd in carbonate form and the reducible Cu,Zn and Pb falled;however,the content of Pb in carbonate formed and the reducible Cd increased.The results indicated that heavy metals(Zn,Cu,Pb and Cd)in sewage sludge could be passivated during composting process.The heavy metals speciation in the compost correlated with the physico-chemical parameters.In addition,linear regression analysis indicated that the content of mobile Pb could predict the total content of Pb.The contents of the residue fraction for Pb,Zn and Cd were decreased,but those for Ni and Cr were increased;the Cu residue fraction was almost constant.The contents of the total mobile fractions(including fractions 1-4)for Zn and Pb were significantly increased,but the increase of those for Cu and Ni were not so remarkable.There were significant degrees of correlation between heavy metal fractions and changes of some selected parameters(for example,pH,composting temperature and OM content).Only the content of the total mobile fractions for Cu could be predictable from its total content.For the prediction of the total mobile fractions of Zn,Ni,Cd and Cr,the R2 value was significantly increased by the inclusion of other variables such as pH,temperature and OM content.展开更多
A rural model composting toilet system still had some pathogens in the compost after months of operation and hence requires a post-treatment. The aim of the study was to sanitize compost withdrawn from the composting ...A rural model composting toilet system still had some pathogens in the compost after months of operation and hence requires a post-treatment. The aim of the study was to sanitize compost withdrawn from the composting toilet by setting post-treatment conditions. The kinetics inactivation of MS2 bacteriophage, selected as indicator for pathogenic viruses were determined during post-treatment at different temperatures (30°C, 40°C and 50°C) with varying moisture contents (50%, 60% and 70%). As a result, the inactivation rates during the post-treatment were 0.093 - 0.020 h-1, 0.025 - 0.088 h1, 0.447 - 0.100 h-1 at 30°C, 40°C and 50°C respectively. The inactivation rate coefficient (k) values of MS2 bacteriophage depended on higher temperature but not on moisture content.展开更多
[Objectives]This study was conducted to provide a theoretical basis for production and application of chicken manure compost.[Methods]With dry manure as a material,the variations of the major nutrients during simple c...[Objectives]This study was conducted to provide a theoretical basis for production and application of chicken manure compost.[Methods]With dry manure as a material,the variations of the major nutrients during simple composting process of dry chicken manure were studied,in order to get the best fermentation method.[Results]Chicken manure should not be preserved wet,but should be preserved after air-drying and fermented before use.Necessary moisture,simple sealing treatment and a certain amount of N element were conducive to simple fermentation of chicken manure.The treatments in which the chicken manure was wrapped around and compacted,added with an appropriate amount of water(50%-60%)and naturally fermented,or was wrapped around and compacted and added with an appropriate amount of water(50%-60%)and 0.2%of urea,were more appropriate for the production directly.[Conclusions]This study provides a theoretical basis for the actual production and application of chicken manure compost.展开更多
Composting is a suitable environment-friendly technique to modify organic waste to organic fertilizers and works as soil conditioners by regulating different biological processes. The main objective of a sustainable a...Composting is a suitable environment-friendly technique to modify organic waste to organic fertilizers and works as soil conditioners by regulating different biological processes. The main objective of a sustainable agricultural production system can be achieved by using quality compost and thereby improving soil health and increased crop yield. This desktop research summarizes the role of composting for sustainable agricultural development with their prospective role, opportunities, and challenges in the context of Bangladesh. Some attention is also given to the composting process and compost industries in Bangladesh. Benefits and constraints regarding the use of compost for achieving sustainable agricultural production systems are also discussed.展开更多
Composting is being widely employed in the treatment of petroleum waste. The purpose of this study was to find the optimum control parameters for petroleum waste in vessel composting. Various physical and chemical par...Composting is being widely employed in the treatment of petroleum waste. The purpose of this study was to find the optimum control parameters for petroleum waste in vessel composting. Various physical and chemical parameters were monitored to evaluate their influence on the microbial communities present in composting. The CO 2 evolution and the number of microorganisms were measured as the activity of composting. The results demonstrated that the optimum temperature, pH and moisture content were 56.5-59.5℃, 7.0-8.5 and 55%-60%, respectively. Under the optimum conditions, the removal efficiency of petroleum hydrocarbon reached 83.29% after 30 days composting.展开更多
Soil quality of garden plants is an important factor for good growth of garden plants.Based on the analysis of the current situation of garden soil,the ecological value and feasibility of composting technology applied...Soil quality of garden plants is an important factor for good growth of garden plants.Based on the analysis of the current situation of garden soil,the ecological value and feasibility of composting technology applied in garden soil improvement were discussed.This study provided a basis for strengthening the quality management of garden soil,improving the standard of garden soil improvement,and helping the healthy and sustainable development of modern garden greening.展开更多
The white-rot fungus, Phanerochaete chrysosporium(P. chrysosporium), was inoculated during different phases of agricultural waste composting and its effect on the spectroscopic characterization of humic acid(HA) was s...The white-rot fungus, Phanerochaete chrysosporium(P. chrysosporium), was inoculated during different phases of agricultural waste composting and its effect on the spectroscopic characterization of humic acid(HA) was studied. Three runs were used in this study: Run A was the control without inoculating, and Runs B and C were inoculated P. chrysosporium during the first and the second fermentation phase, respectively. The elemental analysis, ultra-violet spectroscopy(UV), fluorescence spectra, Fourier transform infra-red(FTIR) and 13 C nuclear magnetic resonance(13C-NMR) of HA all lead to the same conclusion, that is, the degree of aromatization and polymerization of HA increases after 42 days composting. However, the inoculation during different phases presents different effects. P. chrysosporium increases the degree of aromatization and polymerization of HA when it is inoculated during the second fermentation phase, while it does not produce an obvious change on the humification degree of HA when it is inoculated during the first fermentation phase.展开更多
One of the major problems of agricultural soils in the tropical regions of the Pacific is the low organic matter content.Because of the hot and humid environment,the soil organic matter(SOM)is minimal due to rapid dec...One of the major problems of agricultural soils in the tropical regions of the Pacific is the low organic matter content.Because of the hot and humid environment,the soil organic matter(SOM)is minimal due to rapid decomposition.Composted organic material is being applied on agricultural fields as an amendment to provide nutrients and enhance the organic matter content for improving the physical and chemical properties of the cultivated soils.In addition land application of composted material as a fertilizer source effectively disposes of wastes that otherwise are buried in landfills.In our soil program at the University of Guam,we are evaluating the use of organic material as an alternative to synthetic fertilizers.Its goal is to develop management strategies and use available resources for improving crop production while conserving resources and preserving environmental quality.Our case study project is designed to improve soil fertility status by using composted organic wastes and assessing how the nitrogen and other essential nutrients contribute to long-term soil fertility and crop productivity without application of synthetic fertilizers.In our pilot project,compost is produced from wood chips,grinded typhoon debris mixed with animal manure,fish feed,shredded paper and other organic wastes.Mature compost is then applied on the field at the rates of 0,5,10 and 20 t/ha as a soil amendment on the eroded cobbly soils of southern Guam.Corn is planted and monitored for growth performance and yield.The effect of land application of composted material on the SOM content and overall soil quality indices are being evaluated in this pilot study.展开更多
The compost of cattle manure was inoculated with complex microbial agent lower than 5℃ to explore the application of beneficial microbial agent and maturation accelerator aiming at accelerating the process of compost...The compost of cattle manure was inoculated with complex microbial agent lower than 5℃ to explore the application of beneficial microbial agent and maturation accelerator aiming at accelerating the process of compostimg under the low temperature.Results showed that adding the maturation accelerator accelerated the process of composting and increased the nitrogen content of composting products.Inoculating the microogannic maturation agent made the composting temperature rise quickly and the maturation become better.展开更多
In order to examine the optimal design and operating parameters in composting of waste activated sludge,a series of experiments were conducted to discuss the optimal operating parameters for aerobic composting of wast...In order to examine the optimal design and operating parameters in composting of waste activated sludge,a series of experiments were conducted to discuss the optimal operating parameters for aerobic composting of waste activated sludge obtained from Vinh Loc Industrial Park that is located in Ho Chi Minh City.The study was done by optimizing the ratios of sludge/inactive fillers and sludge/microbial products to improve the composting efficiency.After 50 days of composting,the composts of all experiment batches met the microorganism-organic fertilizer standards of 10 TCN 526:2002.The study indicated that the highest efficiency decomposition was obtained at the ratio of a sludge/inactive fillers of 1/0.1 and sludge/microbial products of 1/0.05:TOC(Total Organic Carbon)reduced by 20.2%,loss of Nitrogen was trivial(0.53%),the highest temperature reached at 55.5 oC and lasting for 5 days which ensures elimination of pathogens.However,the addition of nitrogen compounds during the composting is necessary to ensure the compost product can meet the nitrogen standard of microorganism-organic fertilizer.展开更多
The paper presented an assessment of the resource potentials of composting organic waste materials arising from the municipal solid waste stream from cities in Nigeria. Through a review of quantitative data, the compo...The paper presented an assessment of the resource potentials of composting organic waste materials arising from the municipal solid waste stream from cities in Nigeria. Through a review of quantitative data, the composition of municipal solid waste arising within cities in Nigeria was examined in order to identify the potentials for composting organic materials from the waste stream composition. The data showed that the average majority of the waste stream was organic materials which implied high potentials for composting organic waste materials from Nigerian cities. The review also identified further potentials for composting was associated with the large population and the majority of them engaged in agriculture, as a high potential market for compost manure in Nigeria. There were more potentials derivable from the current policies of importing and supplying chemical fertilizer with huge subsidies for domestic agriculture in the country. The need to substitute these policies of chemical fertilizer with the use of compost manure implied high potentials for composting in the country. The paper also identified numerous benefits of composting in general and with particular reference to the Nigerian situation which includes, among others a reduction of the vast quantity of solid waste for final disposal, reducing air pollution and ground water leachate and also employment generation and increased income. Therefore, the paper recommended a deliberate government policy to promote composting of organic solid wastes material and marketing of compost manure to substitute the current policies of importing chemical fertilizer with subsidy for domestic agriculture as a strategy to achieve sustainable waste management in Nigeria.展开更多
Microbial communities and enzyme activities are the main players during municipal solid waste (MSW) composting, but the relationship between microbial communities (i.e., mesophilic and thermophilic ones) and enzyme ac...Microbial communities and enzyme activities are the main players during municipal solid waste (MSW) composting, but the relationship between microbial communities (i.e., mesophilic and thermophilic ones) and enzyme activities (i.e., dehydrogenase, β-glucosidase, phosphatase and urea) has not been well studied. Therefore, the objective of this work is to determine the enzymes profiles during municipal solid waste (MSW) composting and study the relationship between the mesophilic and thermophilic microbial profiles and enzyme activities. MSW was composted in a bench-scale composting reactor. Parameters including temperature, oxygen uptake rate, numbers of microbial populations (mesophilic and thermophilic bacteria and fungi) and enzyme activities were measured. Results showed higher dehydrogenase activities are related to higher numbers of mesophilic bacteria, while higher phosphatase and urea activities are associated with higher numbers of thermophilic fungi and mesophilic bacteria at the later stage of composting. In addition, results of the correlation analysis indicated significant correlations among enzyme activities and microbial population.展开更多
There is growing interest in the potential for using composts in agricultural and horticultural field crops. The aim of this study is to test the mixture efficiency to produce good quality compost. This paper presents...There is growing interest in the potential for using composts in agricultural and horticultural field crops. The aim of this study is to test the mixture efficiency to produce good quality compost. This paper presents a comprehensive analysis of recycling organic wastes through composting. In an area of approximately 1500 ha, situated in the lower valley of the Rio Negro (Black River), onions are produced. 50% of these onions are processed under Good Agricultural Practices (GAP) and under Good Manufacturing Practices (GMP). The packaging for marketing in processing plants has produced huge volumes of wastes that must be managed according to quality standards. These are composed by scales, roots and leaves, with high C/N ratio. In this study the composting process was studied as a way to recycle ecological and cheap onion waste in order to minimize their environmental impact. The onion residues were mixed with alfalfa and cattle manure. An experiment was carried out in order to determine suitable quality compost (organic product high agronomic value). In order to achieve the objectives, composting processes were carried out in two consecutive years. During the process, some physical, chemical and biological properties of the final product were analyzed and evaluated. The mixtures: OMA, onion-manure-alfalfa;OM, onion-manure;OA, onion-alfalfa, showed a similar behavior. The mixtures more efficient were onion-manure and onion-manure-alfalfa with values close to 50%, while onion-alfalfa yielded only 34%. Reuse of onion waste by composting mixed with cattle manure, is a viable alternative in ecological terms. The final compost obtained could be used as amendment in agriculture practices.展开更多
文摘Composting as a solution to the increasing generation of municipal solid waste (MSW), also contribute to GHGs emission when not controlled and could lack some basic nutrients, especially nitrogen. This study assessed the split-additions of nitrogen-rich substrate to composting materials and their effect on GHGs emissions as well as the quality of the composts. Nitrogen-rich substrates formulated from pig and goat manure were co-composted with MSW for a 12-weeks period by split adding at mesophilic (˚C) and thermophilic (>50˚C) stages in five different treatments. Representative samples from the compost were taken from each treatment for physicochemical, heavy metals and bacteriological analysis. In-situ CH<sub>4</sub>, CO<sub>2</sub>, N<sub>2</sub>O gas emissions were also analyzed weekly during composting. It was observed that all the treatments showed significant organic matter decomposition, reaching thermophilic temperatures in the first week of composting. The absence affects the suitable agronomic properties. All nitrogen-rich substrate applied at thermophilic stage (Treatment two) recorded the highest N, P and K concentrations of 1.34%, 0.97% and 2.45%, respectively with highest nitrogen retention. In terms of GHG emissions, CO<sub>2</sub> was highest at the thermophilic stage when N-rich substrate was added in all treatment, while CH<sub>4</sub> was highest in the mesophilic stage with N-rich substrate addition. N<sub>2</sub>O showed no specific trend in the treatments. Split addition of the N-rich substrate for co-composting of MSW produced compost which is stable, has less nutrient loss and low GHG emissions. Split addition of a nitrogen-rich substrate could be an option for increasing the fertilizer value of MSW compost.
基金the National Natural Science Foundation of China(41861124004)the China Postdoctoral Science Foundation(2017M613260)the National Key Research and Development Program of China(2016YFD0501406).
文摘Pollution of arable land caused by heavy metals in livestock and poultry manure has become a potential threaten to human health in China.Safe disposal of the contained toxic pollution with animal manure by co-composting with biochar is one of the alternative methods.Biochars from different sources(wheat straw,peanut shells and rice husks)amended with different loading rates were investigated for passivations of copper and zinc(Cu and Zn)in swine manure composting.Results showed that the passivation effects of the three types of biochar on Cu and Zn were enhanced with increasing biochar dose.Contents of Cu and Zn measured by diethylenetriaminepentaacetic acid(DTPA)and Community Bureau of Reference(CBR)showed that wheat straw biochar with the loading rates of 10%–13%(w/w)was superior to the other two types of biochar in this study.Compared with the control,sample from wheat straw biochar was more favorable for the bacterial growth of Proteobacteria,Firmicutes and Actinobacteria.In addition,pot experiment showed that organic fertilizer amended with wheat straw biochar could significantly improve the growth of Chinese pakchoi and enzyme activities(superoxide dismutase,peroxidase,polyphenol oxidase and catalase)as compared with the control.Cu and Zn contents of Chinese pakchoi in the organic fertilizer group containing wheat straw biochar reduced by 73.2%and 45.2%,65.8%and 33.6%,respectively,compared with the group without loading biochar.There was no significant difference in the contents of vitamin C and reducing sugar between the groups of organic fertilizer amended with/without wheat straw biochar,however,there was significant difference compared with the heavy metal addition group.The application of organic fertilizer formed by adding biochar can effectively reduce the adverse effects of heavy metals on crops.
文摘Composting is now suggested as one of the environmentally and friendly alternative method for disposal of solid organic wastes, as it leads to minimization, stabilization, and utilization of organic waste. Transformations of nitrogen were investigated in co composting of pig manure with different amendments, such as sawdust and leaves. Samples were analyzed for pH, total N, soluble NH 4 N, soluble NO 3 N and soluble organic N. The total N increased after 63 days of composting, as well as the soluble NO 3 N and soluble organic N. Soluble NH 4 N increased significantly and showed peak values at day 7, thereafter decreased sharply and gradually to lower levels. Seed germination index (GI) showed that co composting of pig manure with sawdust reached maturity after 49 days of composting, while co composting of pig manure with sawdust and leaves required shorter time for 35 days. Soluble NH 4 N was significantly negatively ( P <0.05), while soluble NO 3 N and soluble organic N were significantly positively ( P <0.05), correlated with seed germination index (GI). Addition of leaves in co composting of pig manure with sawdust had no significant impacts on nitrogen transformations, but it was beneficial for maturity of pig manure compost.
基金the National Key Research and Development Program of China(2018YFD0500205)the Strategic Priority Research Program of the Chinese Academy Sciences(XDA23070502)。
文摘Available information on the microbial mechanisms associated with heavy metal(HM)passivation during co-composting amended with phosphate rock(PR)remains limited.Thus,this study investigated the dynamic changes in bacterial communities and HM-fractions(Zn,Cu,Cd,Cr and Pb)during swine manure composting with maize straw,and ascertained the bacterial influence on HM-passivation.The results demonstrated that the addition of PR improved HM-passivation,especially for Zn and Cd,with their bioavailability factors(BFs)reduced by 247.41 and 176.25%,respectively.As for bacterial communities,the proportion of Firmicutes decreased,while the proportions of Proteobacteria,Bacteroidetes,DeinococcusThermus and Gemmatimonadetes increased in all treatments.PR significantly changed the primary bacterial phyla in the thermophilic phase.Bacteroidetes were the main bacterial component controlling the passivation of Zn,Cu and Cr,while Deinococcus-Thermus mainly regulated the mobility of Zn and Pb,and Proteobacteria only dominated the transformation among Cd-fractions.These results may provide a reference for the use of HM-passivation techniques during composting.
基金the National Key Technology R&D Program of China(2018YFD0500206)the National Natural Science Foundation of China(31572209,31772395 and 31972943)the Foundation for Safety of Agricultural Products by Ministry of Agriculture and Rural Affairs,China(GJFP2019033)。
文摘Effects of the heavy metal copper(Cu), the metalloid arsenic(As), and the antibiotic oxytetracycline(OTC) on bacterial community structure and diversity during cow and pig manure composting were investigated. Eight treatments were applied, four to each manure type, namely cow manure with:(1) no additives(control),(2) addition of heavy metal and metalloid,(3) addition of OTC and(4) addition of OTC with heavy metal and metalloid;and pig manure with:(5) no additives(control),(6) addition of heavy metal and metalloid,(7) addition of OTC and(8) addition of OTC with heavy metal and metalloid. After 35 days of composting, according to the alpha diversity indices, the combination treatment(OTC with heavy metal and metalloid) in pig manure was less harmful to microbial diversity than the control or heavy metal and metalloid treatments. In cow manure, the treatment with heavy metal and metalloid was the most harmful to the microbial community, followed by the combination and OTC treatments. The OTC and combination treatments had negative effects on the relative abundance of microbes in cow manure composts. The dominant phyla in both manure composts included Actinobacteria, Bacteroidetes, Firmicutes, and Proteobacteria. The microbial diversity relative abundance transformation was dependent on the composting time. Redundancy analysis(RDA) revealed that environmental parameters had the most influence on the bacterial communities. In conclusion, the composting process is the most sustainable technology for reducing heavy metal and metalloid impacts and antibiotic contamination in cow and pig manure. The physicochemical property variations in the manures had a significant effect on the microbial community during the composting process. This study provides an improved understanding of bacterial community composition and its changes during the composting process.
基金This study was jointly supported by the National Key R&D Program of China(2018YFD0500206)the National Natural Science Foundation of China(31772395)+1 种基金the Fundamental Research Funds for Central Non-profit Scientific Institutions,China(1610132019046)the Science and Technology Support Project of Langfang,Hebei,China(2019013125).
文摘Oxytetracycline(OTC)residues have been found in soil and water,and they may pose potential risks to agricultural ecological environments.One of the most impactful ways for OTC to enter the soil and water environments is through excrement used as organic fertilizer.Therefore,it is important to remove OTC during manure composting and to understand the transformation of the organic materials during composting in the presence of OTC.In the present paper,chicken manure and wheat sawdust spiked with OTC were composted under different initial moisture contents(MC)to evaluate the degradation of OTC and changes of organic matter during the composting process.The MC has a significant effect on OTC degradation during composting.A higher MC of 65% was more conducive to OTC degradation(77.4%)and compost maturity compared to the lower MC.However,the higher MC of 65%could increase the ammonia volatilization by promoting nitrification compared to the lower MC.An increase in the initial MC could improve the composting temperature.NMR results illustrated that the presence of OTC could affect the internal transformation of aliphatics,and OTC inhibited compost humification.Thus,an initial MC of 55–65% can alleviate the impacts of OTC on humification during manure composting.
文摘Actinomycetes are known to produce an extensive range of bioactive compounds as well as variety of enzymes having multiple biotechnological applications. They are an important source of lignocellulose hydrolyzing enzymes and constitute considerable proportion of the soil or aquatic micro-flora responsible for degradation of biomass in natural environment. Presently, most of the commercially exploited lignocellulases and commercial biodegradation processes rely mostly on fungal or bacterial micro-organisms. Actinomycetes are relatively less explored for biodegradation processes that utilize lignocellulases for solid agro-waste management and waste water treatment. There is also a need to search and explore novel actinomycete strains for various biodegradation applications. This study involved examining the possibility of using only potent actinomycetes strains for the composting process by creating the consortium of such strains that could produce thermo-tolerant and alkali-tolerant key enzymes necessary for the degradation of cellulose, hemi-cellulose and lignin. The newly developed actinomycete consortium was tested for the composting activity and the composting process was optimized. The analysis of the composted material generated under ideal condition, demonstrated desirable physical and chemical characteristics. Paper pulp effluent poses a hazard to waterways due to toxicity. The toxicity of this mill effluent can be attributed to a compound called lignin and its chlorinated derivatives that are let out during the treatment of lignocellulosic constituents. Current study also involves the use of a strain of actinomycete having ability to produce enzyme laccase, which is active under alkaline condition for the treatment of paper pulp effluent. Enzyme laccase is known for its ability to attack phenolic components of lignin and common hazardous component of effluent, polycyclic aromatic hydrocarbons (PAH). Aerobic treatment of effluent by actinomycete strain indicated 21% reduction in COD at pH 7.5 after 14 days under optimum condition. This strain was identified as Streptomyces rochei based on molecular fingerprinting and was reported to be the producer of laccase probably for the first time. LCMS analysis of the treated effluent sample showed the presence of degradation compounds forming after 7 and 14 days of treatment. These compounds showed the degradation of lignin components and other phenolic, non-phenolic components of the effluent by intra molecular re-arrangement, oxidation and ring opening reactions. Overall, potent thermo-tolerant and alkali-tolerant actinomycete strains were successfully isolated and applied for bio-degradation of domestic agro-waste by composting and treatment of pulp-paper mill effluent. The consortium of these strains may be further utilized for scale-up studies in order to assess its commercial feasibility for biodegradation processes.
基金Supported by the National Natural Science Fund of China(31372351,31272484)。
文摘The evolution of metal species during sludge composting in aerobic reactor has been widely investigated,but little is known in large scale.In this study,the transformations of heavy metals speciation(Zn,Cu,Pb and Cd)in the process of sludge composting were studied in a bunker.Physico-chemical parameters,such as pH,moisture content(MC),organic matter(OM),humic acids(HA)and fulvic acids(FA)contents,were determined to evaluate their impacts on the redistribution of Zn,Cu,Pb and Cd in sludge compost.During the composting process,the contents of Cu,Pb,Zn and Cd in oxidizable and residual forms increased,whereas the contents of the exchangeable Cu,Pb,Zn and Cd decreased,with a slight increase in the total heavy metal contents.The contents of Cu,Zn and Cd in carbonate form and the reducible Cu,Zn and Pb falled;however,the content of Pb in carbonate formed and the reducible Cd increased.The results indicated that heavy metals(Zn,Cu,Pb and Cd)in sewage sludge could be passivated during composting process.The heavy metals speciation in the compost correlated with the physico-chemical parameters.In addition,linear regression analysis indicated that the content of mobile Pb could predict the total content of Pb.The contents of the residue fraction for Pb,Zn and Cd were decreased,but those for Ni and Cr were increased;the Cu residue fraction was almost constant.The contents of the total mobile fractions(including fractions 1-4)for Zn and Pb were significantly increased,but the increase of those for Cu and Ni were not so remarkable.There were significant degrees of correlation between heavy metal fractions and changes of some selected parameters(for example,pH,composting temperature and OM content).Only the content of the total mobile fractions for Cu could be predictable from its total content.For the prediction of the total mobile fractions of Zn,Ni,Cd and Cr,the R2 value was significantly increased by the inclusion of other variables such as pH,temperature and OM content.
文摘A rural model composting toilet system still had some pathogens in the compost after months of operation and hence requires a post-treatment. The aim of the study was to sanitize compost withdrawn from the composting toilet by setting post-treatment conditions. The kinetics inactivation of MS2 bacteriophage, selected as indicator for pathogenic viruses were determined during post-treatment at different temperatures (30°C, 40°C and 50°C) with varying moisture contents (50%, 60% and 70%). As a result, the inactivation rates during the post-treatment were 0.093 - 0.020 h-1, 0.025 - 0.088 h1, 0.447 - 0.100 h-1 at 30°C, 40°C and 50°C respectively. The inactivation rate coefficient (k) values of MS2 bacteriophage depended on higher temperature but not on moisture content.
基金Innovation Project of Hebei Academy of Agriculture and Forestry Sciences(2019-3-4-4,2020-3-4-6)the Earmarked Fund for China Agriculture Research System(CARS-28-27)。
文摘[Objectives]This study was conducted to provide a theoretical basis for production and application of chicken manure compost.[Methods]With dry manure as a material,the variations of the major nutrients during simple composting process of dry chicken manure were studied,in order to get the best fermentation method.[Results]Chicken manure should not be preserved wet,but should be preserved after air-drying and fermented before use.Necessary moisture,simple sealing treatment and a certain amount of N element were conducive to simple fermentation of chicken manure.The treatments in which the chicken manure was wrapped around and compacted,added with an appropriate amount of water(50%-60%)and naturally fermented,or was wrapped around and compacted and added with an appropriate amount of water(50%-60%)and 0.2%of urea,were more appropriate for the production directly.[Conclusions]This study provides a theoretical basis for the actual production and application of chicken manure compost.
文摘Composting is a suitable environment-friendly technique to modify organic waste to organic fertilizers and works as soil conditioners by regulating different biological processes. The main objective of a sustainable agricultural production system can be achieved by using quality compost and thereby improving soil health and increased crop yield. This desktop research summarizes the role of composting for sustainable agricultural development with their prospective role, opportunities, and challenges in the context of Bangladesh. Some attention is also given to the composting process and compost industries in Bangladesh. Benefits and constraints regarding the use of compost for achieving sustainable agricultural production systems are also discussed.
文摘Composting is being widely employed in the treatment of petroleum waste. The purpose of this study was to find the optimum control parameters for petroleum waste in vessel composting. Various physical and chemical parameters were monitored to evaluate their influence on the microbial communities present in composting. The CO 2 evolution and the number of microorganisms were measured as the activity of composting. The results demonstrated that the optimum temperature, pH and moisture content were 56.5-59.5℃, 7.0-8.5 and 55%-60%, respectively. Under the optimum conditions, the removal efficiency of petroleum hydrocarbon reached 83.29% after 30 days composting.
基金Sponsored by Undergraduate Innovation and Entrepreneurship Training Project of Tianjin City in 2018(201810061089)Agricultural Science and Technology Plan Project of Baodi District(2018035)The University Young and Middle-aged Backbone Innovation Talent Training Program in Tianjin(J01009030709)
文摘Soil quality of garden plants is an important factor for good growth of garden plants.Based on the analysis of the current situation of garden soil,the ecological value and feasibility of composting technology applied in garden soil improvement were discussed.This study provided a basis for strengthening the quality management of garden soil,improving the standard of garden soil improvement,and helping the healthy and sustainable development of modern garden greening.
基金Projects(5110817851108423+2 种基金5103900151378190)supported by the National Natural Science Foundation of ChinaProject(20100161110012)supported by the Research Fund for the Doctoral Program of Higher Education of China
文摘The white-rot fungus, Phanerochaete chrysosporium(P. chrysosporium), was inoculated during different phases of agricultural waste composting and its effect on the spectroscopic characterization of humic acid(HA) was studied. Three runs were used in this study: Run A was the control without inoculating, and Runs B and C were inoculated P. chrysosporium during the first and the second fermentation phase, respectively. The elemental analysis, ultra-violet spectroscopy(UV), fluorescence spectra, Fourier transform infra-red(FTIR) and 13 C nuclear magnetic resonance(13C-NMR) of HA all lead to the same conclusion, that is, the degree of aromatization and polymerization of HA increases after 42 days composting. However, the inoculation during different phases presents different effects. P. chrysosporium increases the degree of aromatization and polymerization of HA when it is inoculated during the second fermentation phase, while it does not produce an obvious change on the humification degree of HA when it is inoculated during the first fermentation phase.
文摘One of the major problems of agricultural soils in the tropical regions of the Pacific is the low organic matter content.Because of the hot and humid environment,the soil organic matter(SOM)is minimal due to rapid decomposition.Composted organic material is being applied on agricultural fields as an amendment to provide nutrients and enhance the organic matter content for improving the physical and chemical properties of the cultivated soils.In addition land application of composted material as a fertilizer source effectively disposes of wastes that otherwise are buried in landfills.In our soil program at the University of Guam,we are evaluating the use of organic material as an alternative to synthetic fertilizers.Its goal is to develop management strategies and use available resources for improving crop production while conserving resources and preserving environmental quality.Our case study project is designed to improve soil fertility status by using composted organic wastes and assessing how the nitrogen and other essential nutrients contribute to long-term soil fertility and crop productivity without application of synthetic fertilizers.In our pilot project,compost is produced from wood chips,grinded typhoon debris mixed with animal manure,fish feed,shredded paper and other organic wastes.Mature compost is then applied on the field at the rates of 0,5,10 and 20 t/ha as a soil amendment on the eroded cobbly soils of southern Guam.Corn is planted and monitored for growth performance and yield.The effect of land application of composted material on the SOM content and overall soil quality indices are being evaluated in this pilot study.
基金Supported by Post-doctoral Management Office of Heilongjiang Province (LBH-Z06161)Key Lab of Utilization and Protection of BlackSoil (GXS08-1)Special-fund Project of Harbin Scientific Innovation Talented Person Studies (Youth Scientific Innovation Talented Person)(2009RFQXN098)
文摘The compost of cattle manure was inoculated with complex microbial agent lower than 5℃ to explore the application of beneficial microbial agent and maturation accelerator aiming at accelerating the process of compostimg under the low temperature.Results showed that adding the maturation accelerator accelerated the process of composting and increased the nitrogen content of composting products.Inoculating the microogannic maturation agent made the composting temperature rise quickly and the maturation become better.
文摘In order to examine the optimal design and operating parameters in composting of waste activated sludge,a series of experiments were conducted to discuss the optimal operating parameters for aerobic composting of waste activated sludge obtained from Vinh Loc Industrial Park that is located in Ho Chi Minh City.The study was done by optimizing the ratios of sludge/inactive fillers and sludge/microbial products to improve the composting efficiency.After 50 days of composting,the composts of all experiment batches met the microorganism-organic fertilizer standards of 10 TCN 526:2002.The study indicated that the highest efficiency decomposition was obtained at the ratio of a sludge/inactive fillers of 1/0.1 and sludge/microbial products of 1/0.05:TOC(Total Organic Carbon)reduced by 20.2%,loss of Nitrogen was trivial(0.53%),the highest temperature reached at 55.5 oC and lasting for 5 days which ensures elimination of pathogens.However,the addition of nitrogen compounds during the composting is necessary to ensure the compost product can meet the nitrogen standard of microorganism-organic fertilizer.
文摘The paper presented an assessment of the resource potentials of composting organic waste materials arising from the municipal solid waste stream from cities in Nigeria. Through a review of quantitative data, the composition of municipal solid waste arising within cities in Nigeria was examined in order to identify the potentials for composting organic materials from the waste stream composition. The data showed that the average majority of the waste stream was organic materials which implied high potentials for composting organic waste materials from Nigerian cities. The review also identified further potentials for composting was associated with the large population and the majority of them engaged in agriculture, as a high potential market for compost manure in Nigeria. There were more potentials derivable from the current policies of importing and supplying chemical fertilizer with huge subsidies for domestic agriculture in the country. The need to substitute these policies of chemical fertilizer with the use of compost manure implied high potentials for composting in the country. The paper also identified numerous benefits of composting in general and with particular reference to the Nigerian situation which includes, among others a reduction of the vast quantity of solid waste for final disposal, reducing air pollution and ground water leachate and also employment generation and increased income. Therefore, the paper recommended a deliberate government policy to promote composting of organic solid wastes material and marketing of compost manure to substitute the current policies of importing chemical fertilizer with subsidy for domestic agriculture as a strategy to achieve sustainable waste management in Nigeria.
文摘Microbial communities and enzyme activities are the main players during municipal solid waste (MSW) composting, but the relationship between microbial communities (i.e., mesophilic and thermophilic ones) and enzyme activities (i.e., dehydrogenase, β-glucosidase, phosphatase and urea) has not been well studied. Therefore, the objective of this work is to determine the enzymes profiles during municipal solid waste (MSW) composting and study the relationship between the mesophilic and thermophilic microbial profiles and enzyme activities. MSW was composted in a bench-scale composting reactor. Parameters including temperature, oxygen uptake rate, numbers of microbial populations (mesophilic and thermophilic bacteria and fungi) and enzyme activities were measured. Results showed higher dehydrogenase activities are related to higher numbers of mesophilic bacteria, while higher phosphatase and urea activities are associated with higher numbers of thermophilic fungi and mesophilic bacteria at the later stage of composting. In addition, results of the correlation analysis indicated significant correlations among enzyme activities and microbial population.
文摘There is growing interest in the potential for using composts in agricultural and horticultural field crops. The aim of this study is to test the mixture efficiency to produce good quality compost. This paper presents a comprehensive analysis of recycling organic wastes through composting. In an area of approximately 1500 ha, situated in the lower valley of the Rio Negro (Black River), onions are produced. 50% of these onions are processed under Good Agricultural Practices (GAP) and under Good Manufacturing Practices (GMP). The packaging for marketing in processing plants has produced huge volumes of wastes that must be managed according to quality standards. These are composed by scales, roots and leaves, with high C/N ratio. In this study the composting process was studied as a way to recycle ecological and cheap onion waste in order to minimize their environmental impact. The onion residues were mixed with alfalfa and cattle manure. An experiment was carried out in order to determine suitable quality compost (organic product high agronomic value). In order to achieve the objectives, composting processes were carried out in two consecutive years. During the process, some physical, chemical and biological properties of the final product were analyzed and evaluated. The mixtures: OMA, onion-manure-alfalfa;OM, onion-manure;OA, onion-alfalfa, showed a similar behavior. The mixtures more efficient were onion-manure and onion-manure-alfalfa with values close to 50%, while onion-alfalfa yielded only 34%. Reuse of onion waste by composting mixed with cattle manure, is a viable alternative in ecological terms. The final compost obtained could be used as amendment in agriculture practices.
