Fulvic acid(FA),typical organic matter derived from humification process in composted sludge,possesses the potential to remediate mine soils contaminated by heavy metals.To understand the cooper(Cu)immobilizing proces...Fulvic acid(FA),typical organic matter derived from humification process in composted sludge,possesses the potential to remediate mine soils contaminated by heavy metals.To understand the cooper(Cu)immobilizing process in open-pit mine soil induced by FA,changes of Cu speciation in mixture of open-pit mine soil and composted sludge was tracked over 180 days.It was observed that the organic-bound and residual fraction of Cu increased dramatically with the corresponding decrease of Fe/Mn oxide-bound Cu in the first 60 days,then the organic-bound fraction decreased to about its initial proportion during 60-120 days,while residual fraction still increased,and the proportion of residual Cu accounted for over85%and became stable after 120 days.To reveal the mechanism of FA inducing Cu fixation on Albite which is the main phase of soil primary ore,two groups of Cu adsorption experiments with and without FA were designed.With the addition of FA,the adsorption capacity of Cu by Albite increased by 1.55 times and the content of residual Cu in Albite increased by7.7 times.It was found that the Cu absorbed in smaller Albite particle induced by FA formed a secondary mineral——Chrysocolla,causing increase of residual fraction of Cu.These results revealed the mechanism:FA was absorbed on the surface of Albite after complexing with Cu ions in the solution,and then it induced Cu into the interlayer and pore channels of Albite.The Cu in the Albite was immobilized by forming Chrysocolla finally.展开更多
Plant pesticide residues, such as chinaberry （Melia toosendan） residue and sand cypress （Sabina vulgaris） residue, are pesticidal plant materials discarded after the bioactive ingredient has been extracted with or...Plant pesticide residues, such as chinaberry （Melia toosendan） residue and sand cypress （Sabina vulgaris） residue, are pesticidal plant materials discarded after the bioactive ingredient has been extracted with organic solvents. The only option for botanical pesticide residue utilization has been as landfill. Chinaberry residue （CBR） and sand cypress residue （SCR） were collected and composted in Yangling, Shaanxi Province, China. We studied the effects of chinaberry residue compost （CBRC）, CBRC incorporated with Trichoderma viride （CBRCT）, sand cypress residue compost （SCRC）, and SCRC incorporated with T. viride （SCRCv） on the root-knot nematode, Meloidogyne incognita, infesting the balloonflower （Platycodon grandiflorum）. Bioassay results indicated that stock solutions of the CBRCT and SCRCT extracts significantly inhibited egg hatching and caused high larval mortality, followed in degree by the CBRC and SCRC extracts. The CBR and SCR extracts caused very low inhibition of eggs and larvae. Supplementing potting mixtures with these four composts reduced the severity of root galling and increased the proportion of marketable roots. The severity of root galling decreased and the average weight of the marketable roots increased with an increase in all the composts when supplemented at rates from 5 to 30%. CBR- and SCR-supplemented pot soils also inhibited the nematodes, but CBR and SCR applied to the soil had a phytotoxic effect and inhibited balloonflower growth. Supplementing field soil with the composts reduced the severity of root galling and the populations of southern root-knot nematodes in the soil. CBRCT and SCRCT clearly enhanced the average weight of the marketable roots by 30.45 and 26.64%, respectively. Continuous supplementation with CBRCT or SCRCT in the same field significantly enhanced the control of the root-knot nematode, and the populations of nematodes continued to decrease with second inoculations. The populations of total Trichoderma spp. were distinctly enhanced and were maintained at high levels for a long time in the supplemented soils.展开更多
Field experiments were conducted to determine the effect of composts prepared from different organic materials with rock phosphate (RP) on yield and P uptake of berseem and their residual effect on maize crop (cv. Aza...Field experiments were conducted to determine the effect of composts prepared from different organic materials with rock phosphate (RP) on yield and P uptake of berseem and their residual effect on maize crop (cv. Azam) during 2011-2012. Composts prepared from RP fed farm yard manure (FYM), simple FYM, organic waste and city garbage were applied at the rate based on their P concentrations. Composts significantly (P ≤ 0.05) increased total dry matter weight of Berseem in first and second cut over control. Residual effect of the prepared composts was determined on yield and plant P uptake of maize in the same layout of Berseem. Maximum and significantly (P ≤ 0.05) higher maize grain yield, total dry matter yield and stover yield of 3161 kg·ha-1, 9633 kg·ha-1 and 6472 kg·ha-1, respectively were recorded by the residual effect of compost of organic waste with half dose of SSP. Thousand grains weight of 220 g was noted in the treatment of residual effect of compost of RP fed FYM with half dose of SSP. Post harvest soil N and P concentrations improved with composting. Significant (P ≤ 0.05) increases in N and P uptake by berseem and maize plants were observed with added composts. Results suggest that the use of composts prepared from different organic materials with RP is environmental friendly and has potential to improve crops yield and plants N and P uptakes for a prolonged time.展开更多
In this work the physical, chemical and microbial properties of four locally composted green waste composts (GWCs) namely Almukhasib, Growers, Plantex, and Super along with four imported GWC (Florabella, Mikskaar, Pot...In this work the physical, chemical and microbial properties of four locally composted green waste composts (GWCs) namely Almukhasib, Growers, Plantex, and Super along with four imported GWC (Florabella, Mikskaar, Potgrond, and Shamrock) were studied to evaluate the quality of these composts with the acceptable standards. All composts showed normal physical properties, except the bad smell from sulfur reducing bacteria in Almukhasib, light brown color Plantex and one viable weed seed in Shamrock compost. The germination indexes of the composts comparable to the standard (90%) were 100% for Mikskaar, followed by Shamrock (92%), Florabella (97), Potgrond (95%), Plantex (98%), Growers (77%), and 5% for both Super and Almukhasib. The physical and chemical properties vary considerably as follows: pH 3 - 10.5, 5.1 - 6.5 (standard 5 - 8), electrical conductivity (EC) 0.4 - 10.2 mS·cm-1, 0.8 - 1.8 mS·cm-1(standard 0.0 - 4.0 mS·cm-1), moisture content (MC%) 29% - 43.7%, 64% - 74% (standard 35% - 60%) and water holding capacity (WHC%) 92% - 200% and 400% - 800% for the locally produced and imported composts, respectively. Wide ranges in the chemical properties were expressed as ammonia concentration 512.4 - 1640.1 mg·kg-1, 459.4 - 656.5 mg·kg-1(standard -1), organic matter 17% - 67.6%, and 53.3% - 66.2% (standard 35%) for the locally composted and imported composts, respectively. The concentrations of the heavy metals (Zn, Ni, Pb, Hg, As, Cd, and Cr) were lower than the recommended levels. The average of the bacterial colony forming unit per gram of locally produced and imported composts ranged between 260 - 1740 CFU/g and 330 - 2870 CFU/g, whereas the fungal CFU were 10 - 2800 CFU/g and 27 - 1800 CFU/g, respectively. The most probable number (MPN) for coliform bacteria was 43 - 1100 CFU/g for locally produced composts, and 23 - 480 CFU/g for the imported composts. Therefore, these composts can not be used directly without effective treatment as substrate for plant growth, soil amendment and as biofertilizer.展开更多
In order to find fermentation starters that can promote rapid and effective composting of chicken manure,shorten the fermentation period,and improve the compost quality,fermentation starters with different microbial c...In order to find fermentation starters that can promote rapid and effective composting of chicken manure,shorten the fermentation period,and improve the compost quality,fermentation starters with different microbial combination ratios(C1,C2,C3,C4 and C5) were designed and fermentation experiment was carried out on these five fermentation starters,commercially available organic fertilizer starter(SS),and chicken manure without inoculating fermentation starter. In the process of the fermentation,the changes in the fermentation temperature,water content and pH value were monitored; the effects of organic manure on the germination rate and growth of rapeseed seeds were measured;viable count,water content,and pH value of prepared fermentation starters were measured; main indicators( organic matter,nitrogen,phosphorus,and potassium) of organic fertilizer generated from fermentation were measured. From the indicators,the formula C3 and C4 were better,in the beginning of fermentation,the temperature rose rapidly,and it reached 40 ℃ in the second day; the water content dropped to below 35% in the 18 th day; the pH value underwent the process of declining-rising-stable,and the overall value showed slight rise,but the change was not great( 0-0. 5). C3 and C4 fermentation products had better effects on the germination and growth of rapeseeds. The germination rate of the rapeseed seeds was 100% and 97. 5% and the bud length was 15. 94 mm and 14. 57 mm,respectively,and the root length was45. 97 mm and 39. 44 mm,respectively. The content of organic matter in fermented organic manure was 86. 62% and 85. 17% respectively,and the total content of nitrogen,phosphorus and potassium was 8. 85% and 8. 22% respectively,and the pH was 7. 5 and 8. 0 respectively.All of these complied with the industry standard NY525-2012( organic matter ≥ 45%,and nitrogen,phosphorus,and potassium ≥ 5%,pH 5. 5-8. 5). The fermentation of fresh chicken manure was completed within 20 days,conforming to the requirements of large-scale organic fertilizer production factory for composting chicken manure into organic fertilizer.展开更多
Smallholder farming is promoted for its environmental friendliness, assurance of food security sovereignty and conservation of indigenous knowledge. However, in actual practice, Smallholder farmers recycle farm plant ...Smallholder farming is promoted for its environmental friendliness, assurance of food security sovereignty and conservation of indigenous knowledge. However, in actual practice, Smallholder farmers recycle farm plant waste to improve soil fertility. By so doing, they contribute to environmental pollution, emissions, and global warming. This situation is a Smallholder farmers’ challenge worldwide. One of these challenges is the inability to find cheaper sources of plant nutrients. These sources of nutrients are associated with environmental pollution, such as the release of Methane. This study focused on farm wastes (bean trash, maize trash, banana trash, cattle slurry, goat slurry, and pig slurry) commonly produced by smallholder farmers in two farming systems of Masaka and Lyantonde Districts to explore the effects of composting and surface decomposition on nutrients contained in farm wastes by specifically: estimating baseline nutrient contents in farm wastes before disposal, determining the variation of nutrients of farm wastes managed by composting and surface decomposition and the potential source of major nutrients among selected farm wastes. Through carbon analysis, Calorimetric determination of Nitrogen and Phosphorus analysis using a block digester and UV-Visible spectrometer, Carbon, Nitrogen, Potassium and Phosphorus were determined from bean trash, maize trash, banana trash, cattle slurry, goat slurry, and pig slurry. Results revealed that goat slurry, chicken waste, maize trash and pig slurry contained more and retained more P, K, C and N, respectively, as compared to other farm wastes. Significant volumes of N and P were retained in composted materials as compared to those managed by surface decomposition.展开更多
The potential use ofcomposted wood fibre waste （WFW） for the cultivation of bacterial antagonists of Sclerotinia minor was examined with the result that a mix of millet seed （20% w/w） and WFW, suitably amended wit...The potential use ofcomposted wood fibre waste （WFW） for the cultivation of bacterial antagonists of Sclerotinia minor was examined with the result that a mix of millet seed （20% w/w） and WFW, suitably amended with nutrients, proved to be an ideal matrix for the growth of some of these bacteria. Densities in terms ofcfu＇s ranged from 8.5 IOgl0 cfu/g dw to 10.5 logl0 cfu/g dw ullder sterile conditions after 14 days incubation. Lower population densities of the antagonists were achieved under non-sterile conditions in the compost： millet mix of between 7.9-9.3 logm cfu/g dw at the same period. However, when applied in a pot （glasshouse） trial to protect against S. minor, the millet seed appeared to stimulate the growth of this pathogen resulting in a high incidence of attack of lettuce plants after 2-3 weeks. Although the percentage of healthy seedlings increased following application of compost mix grown antagonists （at a rate of 5% v/v） when compared to the control treatment, these values were not statistically significant （p〉0.05） in most cases. Therefore, the use of millet seeds cannot be recommended as a nutrient supplement for the bacterial antagonist cultivation, if to be subsequently used to control fungal pathogens in the field.展开更多
Biochar is widely recognized as an amendment that enhances soil properties and sequesters carbon,particularly in degraded soils.However,biochar applied solely to soil may also hinder plant development due to toxic by-...Biochar is widely recognized as an amendment that enhances soil properties and sequesters carbon,particularly in degraded soils.However,biochar applied solely to soil may also hinder plant development due to toxic by-products generated during pyrolysis or nutrient retention.To mitigate these adverse effects,it has been suggested to either mix biochar with compost or to process it by composting with fresh organic materials.To date,there is a lack of comparative studies evaluating the performance of these two approaches.In this study,three types of biochar,differing in their initial feedstocks(beech wood,hornbeam/beech/oak mixture,and digestate/cereal straw mixture),were investigated.These biochars were applied solely,mixed with green waste compost,or processed as composted biochar in two soils of different fertility(a Luvisol and a gleyic Fluvisol).A pot experiment was conducted under controlled conditions where lettuce was grown for three months.After harvesting,plant biomass,and soil microbial and physicochemical properties were measured.Composted biochar and compost additives maintained a neutral soil pH,contrary to biochar applied solely or mixed with compost.The dissolved organic carbon and total nitrogen were higher in composted biochar treatments,leading to a higher proportion of humified material with a high degree of condensed aromatic groups compared to other treatments.Microbial activities were higher in the composted biochar treatments compared to those in the compost with biochar,and more specifically in the less fertile Luvisol.Finally,composted biochar increased plant growth by almost six times compared to the control without amendments,whereas the mix of biochar and compost increased it by only three times.Solely applied biochars did not affect lettuce growth.This study demonstrates that biochar composting is more beneficial than mixing biochar with compost in terms of improving soil fertility and mitigating the negative effects associated with pure biochar application.展开更多
The purpose of this study was to quantify the release of nitrate into vadose zone as well as the nitrogen-holding capacity of compost applied on calcareous soils of northern Guam amended with both inorganic fertilizer...The purpose of this study was to quantify the release of nitrate into vadose zone as well as the nitrogen-holding capacity of compost applied on calcareous soils of northern Guam amended with both inorganic fertilizer and composted organic waste,to examine potentially adverse effect of these nutrient materials to groundwater quality.Three different nitrogen levels each of the composted organic waste and the inorganic fertilizer were applied to corn(maize)(farmland)study plots for three consecutive seasons,two dry and one rainy season.During each season,soil organic matter(SOM,w/w%)content and carbon-nitrogen ratio(C/N,w/w%),were determined for analysis of the nitrogen-holding capacity of these calcareous soils.Nitrate levels in soil pore water were also determined for study of potential groundwater contamination.For three seasons,compost plots showed higher SOM%contents and lower C/N%than fertilizer plots.That is,compost-treated soils showed higher SOM content and adsorbed more nitrogen under normalized soil mass than did fertilizer-treated soils.Nitrate levels in pore water were generally higher on compost plots during early stages of corn but were generally higher on fertilizer plots during active leaf,tasseling,and maturity stages.During the rainy season,nitrate leachate seemed to increase,but this trend could not be confirmed because rainfall amounts were not measured.Overall,composted organic waste proved to be a good amendment for soil productivity and agricultural sustainability while reducing nitrate leachate from northern Guam farmland.展开更多
The fact that Morocco is an agricultural country and the large volume of biodegradable waste produced by the population make composting so important.The degradation of organic matter is facilitated by faunal and flora...The fact that Morocco is an agricultural country and the large volume of biodegradable waste produced by the population make composting so important.The degradation of organic matter is facilitated by faunal and floral macro and micro-organisms that act in different stages of maturation;studies on this fauna are quite rare both nationally and internationally.On a sample of two tons of household waste,we documented invertebrates that colonized compost heaps and then assessed the changes in the structure of the invertebrate population during the different phases.Our study revealed the presence of several zoological groups colonizing the compost heaps during the different composting phases;we noted the presence of:(1)Macroscopic invertebrates,in order of number of individuals:insect larvae,ants,earthworms,sowbugs,spiders,springtails,and millipedes,and(2)Microscopic invertebrates,the most abundant in terms of individuals:mites and nematodes.As for the order of appearance,we observed that insect larvae were the first to colonize the compost heap from the very first days of installation,followed by woodlice observed during the thermophilic phase and disappearing towards the end of the process.Earthworms were observed during the end of the thermophilic phase,while springtails were observed more during the cooling and maturation phases.Our study revealed the presence of a good quality of fauna during the composting process,which are indicators of good compost quality and play a major role in the circulation of nutrients,thus ensuring the provision of essential elements for plant nutrition.展开更多
Enhancing A.bisporus L.culture media with nanomaterials and some biostimulants is important for in improving mushroom productivity quantitatively and qualitatively.Magnetic iron nanoparticles(N-FeO),carbon nanotube(CN...Enhancing A.bisporus L.culture media with nanomaterials and some biostimulants is important for in improving mushroom productivity quantitatively and qualitatively.Magnetic iron nanoparticles(N-FeO),carbon nanotube(CNTs)suspensions,effective microorganisms(EM)bio-fertilisers,and growth stimulants(Atonik)were used individually and in combination to enhance the compost culture media.Quantitative and qualitative traits of the mushroom yield were measured.In a simple oOne-Wway experiment that included 16 treatments—Ssingle agents,two-,three-,and four-way Ccombinations and three replications—,the statistical analysis results of Duncan’'s test showed.Tthat the individual impact of the applied study treatments and their combined synergistic effects resulted in a significant increase in the traits of the number of fruiting bodies,fruiting body rate,yield quantity,mushroom biological efficiency ratio,stem length,stem diameter,head diameter,head thickness,carbohydrates content,protein content,ash,and dry matter.The application of Atonik itself resulted in the highest values of fruiting body number,yield,biological efficiency,and stem length,which were respectively were 128.33 body bags^(-1),2814 g bag-1,37.52%,and 3.03 cm,compared to the control of 32.33 body bags^(-1),749 g bag-1,9.98%,and 1.72 cm.The treatments NFeO+CNT+EM+ATO resulted in a significant increase in the traits of the fruiting body rate,stem length,and carbohydrate content by 32.69 g,3.40 cm,and 16.78%,respectively,compared to the control of 22.97 g,1.72 cm,and 8.16%,respectively.展开更多
Rice straw,which is produced after the harvest of rice,is a major agricultural waste in the world.Rice straw has a high carbon/nitrogen ratio and is more resistant to microbial degradation than other straws because it...Rice straw,which is produced after the harvest of rice,is a major agricultural waste in the world.Rice straw has a high carbon/nitrogen ratio and is more resistant to microbial degradation than other straws because its main constituents are cellulose and hemicelluloses encrusted by lignin.When rice straw is burned,hazardous substances such as carbon dioxide,methane,carbon monoxide,and nitrogen monoxide are released into the air as smoke(less than 10μm-sized particles).The rise in the burning of rice straw has contributed to too many accidents and health issues in the general population residing in Haryana,Punjab,and Uttar Pradesh of India.These states are being urged by the National Green Tribunal to generate money instead of burning rice straw.Even though these lignocellulosic materials might be beneficial,not much has been carried out with them.This overview covers the properties of rice straw and husks,the numerous procedures used to create valuable products,and various applications that may be made for them.These include energy sources,environmental adsorbents,building supplies,and specialist commodities.展开更多
Although the efficiency of poly(ethylene terephthalate)(PET)degradation has been successfully improved by depolymerase engineering,mostly by using Goodfellow-PET(gf-PET)as a substrate,efforts to degrade unpretreated P...Although the efficiency of poly(ethylene terephthalate)(PET)degradation has been successfully improved by depolymerase engineering,mostly by using Goodfellow-PET(gf-PET)as a substrate,efforts to degrade unpretreated PET materials with high crystallinity remain insufficient.Here,we endeavored to improve the degradation capability of a WCCG mutant of leaf-branch compost cutinase(LCC)on a unpretreated PET substrate(crystallinity>40%)by employing iterative saturation mutagenesis.Using this method,we developed a high-throughput screening strategy appropriate for unpretreated substrates.Through extensive screening of residues around the substrate-binding groove,two variants,WCCG-sup1 and WCCG-sup2,showed good depolymerization capabilities with both high-(42%)and low-crystallinity(9%)substrates.The WCCG-sup1 variant completely depolymerized a commercial unpretreated PET product in 36 h at 72℃.In addition to enzyme thermostability and catalytic efficiency,the adsorption of enzymes onto substrates plays an important role in PET degradation.This study provides valuable insights into the structure-function relationship of LCC.展开更多
This study explored the combined effects of Bacillus subtilis inoculation with biochar on the evolution of bacterial communities,antibiotic resistance genes(ARGs),and mobile genetic elements(MGEs)during the composting...This study explored the combined effects of Bacillus subtilis inoculation with biochar on the evolution of bacterial communities,antibiotic resistance genes(ARGs),and mobile genetic elements(MGEs)during the composting of chicken manure.The results showed that B.subtilis inoculation combined with biochar increased bacterial abundance and diversity as well as prolonged the compost thermophilic period.Promoted organic matter biodegradation and facilitated the organic waste compost humification process,reduced the proliferation of ARGs by altering the bacterial composition.Firmicutes and Actinobacteriota were the main resistant bacteria related to ARGs and MGEs.The decrease in ARGs and MGEs was associated with the reduction in the abundance of related host bacteria.Compost inoculation with B.subtilis and the addition of biochar could promote nutrient transformation,reduce the increase in ARGs and MGEs,and increase the abundance of beneficial soil taxa.展开更多
Microbial activity and interaction are the important driving factors in the start-up phase of food waste composting at low temperature.The aim of this study was to explore the effect of inoculating Bacillus lichenifor...Microbial activity and interaction are the important driving factors in the start-up phase of food waste composting at low temperature.The aim of this study was to explore the effect of inoculating Bacillus licheniformis on the degradation of organic components and the potential microbe-driven mechanism from the aspects of organic matter degradation,enzyme activity,microbial community interaction,and microbial metabolic function.The results showed that after inoculating B.licheniformis,temperature increased to 47.8℃ on day2,and the degradation of readily degraded carbohydrates(RDC)increased by 31.2%,and the bioheat production increased by 16.5%.There was an obvious enhancement of extracellular enzymes activities after inoculation,especially amylase activity,which increased by 7.68 times on day 4.The inoculated B.licheniformis colonized in composting as key genus in the start-up phase.Modular network analysis and Mantel test indicated that inoculation drove the cooperation between microbial network modules who were responsible for various organic components(RDC,lipid,protein,and lignocellulose)degradation in the start-up phase.Metabolic function prediction suggested that carbohydrate metabolisms including starch and sucrose metabolism,glycolysis/gluconeogenesis,pyruvate metabolism,etc.,were improved by increasing the abundance of related functional genes after inoculation.In conclusion,inoculating B.licheniformis accelerated organic degradation by driving the cooperation between microbial network modules and enhancing microbial metabolism in the start-up phase of composting.展开更多
SiGe-based thermoelectric(TE)materials have gained increasing interests due to their low maintenance costs,environmental friendliness and long lifespan.However,the intrinsically high thermal conductivity of Si-based m...SiGe-based thermoelectric(TE)materials have gained increasing interests due to their low maintenance costs,environmental friendliness and long lifespan.However,the intrinsically high thermal conductivity of Si-based materials also results in poor TE properties.In this investigation,a zirconia(ZrO_(2))composite strategy was applied to an n-type SiGe alloy,tremendously elevating its TE performance.After mechanical alloying and spark plasma sintering(SPS)processes,the ZrO_(2)induced the formation of nanopores in the SiGe matrix via phosphorus adsorption.Moreover,such increase in porosity enhanced the phonon scattering and dramatically suppressed lattice thermal conductivity,from 2.83 to 1.59 W·m^(-1)·K^(-1)at 873 K.Additionally,reduced phosphorus doping led to an increase in Seebeck coefficients and a relatively minor decrease in electrical conductivity,The power factor didn't deteriorate significantly,either,as its maximum of~3.43 mW·m^(-1-)K^(-2)was achieved at 873 K with(Si_(0.8)Ge_(0.2))_(0.097)P_(0.03)(ZrO_(2))_(0.003).In short,a peak figure of merit(ZT)of~1.27 at 873 K and an average ZT~0.7 from 323 to 873 K were obtained.This study demonstrates that the electrical and thermal transportation of SiGe material can be synergistically tuned by compositing ZrO_(2),illustrating a novel strategy to optimize the TE properties of bulk materials.展开更多
Additives could improve composting performance and reduce gaseous emission,but few studies have explored the synergistic of additives on H_(2)S emission and compost maturity.This research aims to make an investigation...Additives could improve composting performance and reduce gaseous emission,but few studies have explored the synergistic of additives on H_(2)S emission and compost maturity.This research aims to make an investigation about the effects of chemical additives and mature compost on H_(2)S emission and compost maturity of kitchen waste composting.The results showed that additives increased the germination index value and H_(2)S emission reduction over 15 days and the treatment with both chemical additives and mature compost achieved highest germination index value and H_(2)S emission reduction(85%).Except for the treatment with only chemical additives,the total sulfur content increased during the kitchen waste composting.The proportion of effective sulfur was higher with the addition of chemical additives,compared with other groups.The relative abundance of H_(2)S-formation bacterial(Desulfovibrio)was reduced and the relative abundance of bacterial(Pseudomonas and Paracoccus),which could convert sulfur-containing substances and H_(2)S to sulfate was improved with additives.In the composting process with both chemical additives and mature compost,the relative abundance of Desulfovibrio was lowest,while the relative abundance of Pseudomonas and Paracoccus was highest.Taken together,the chemical additives and mature compost achieved H_(2)S emission reduction by regulating the dynamics of microbial community.展开更多
Composting presents a viable management solution for lignocellulose-rich municipal solid waste.However,our understanding about the microbial metabolic mechanisms involved in the biodegradation of lignocellulose,partic...Composting presents a viable management solution for lignocellulose-rich municipal solid waste.However,our understanding about the microbial metabolic mechanisms involved in the biodegradation of lignocellulose,particularly in industrial-scale composting plants,remains limited.This study employed metaproteomics to compare the impact of upgrading from aerated static pile(ASP)to agitated bed(AB)systems on physicochemical parameters,lignocellulose biodegradation,and microbial metabolic pathways during largescale biowaste composting process,marking the first investigation of its kind.The degradation rates of lignocellulose including cellulose,hemicellulose,and lignin were significantly higher in AB(8.21%-32.54%,10.21%-39.41%,and 6.21%-26.78%)than those(5.72%-23.15%,7.01%-33.26%,and 4.79%-19.76%)in ASP at three thermal stages,respectively.The AB system in comparison to ASP increased the carbohydrate-active enzymes(CAZymes)abundance and production of the three essential enzymes required for lignocellulose decomposition involving a mixture of bacteria and fungi(i.e.,Actinobacteria,Bacilli,Sordariomycetes and Eurotiomycetes).Conversely,ASP primarily produced exoglucanase andβ-glucosidase via fungi(i.e.,Ascomycota).Moreover,AB effectively mitigated microbial stress caused by acetic acid accumulation by regulating the key enzymes involved in acetate conversion,including acetyl-coenzyme A synthetase and acetate kinase.Overall,the AB upgraded from ASP facilitated the lignocellulose degradation and fostered more diverse functional microbial communities in large-scale composting.Our findings offer a valuable scientific basis to guide the engineering feasibility and environmental sustainability for large-scale industrial composting plants for treating lignocellulose-rich waste.These findings have important implications for establishing green sustainable development models(e.g.,a circular economy based onmaterial recovery)and for achieving sustainable development goals.展开更多
In this study,high temperature thermotolerant nitrifying bacteria(TNB)and high temperature thermotolerant sulfide oxidizing bacteria(TSOB)were obtained from compost samples and inoculated into sewage sludge(SS)compost...In this study,high temperature thermotolerant nitrifying bacteria(TNB)and high temperature thermotolerant sulfide oxidizing bacteria(TSOB)were obtained from compost samples and inoculated into sewage sludge(SS)compost.The effects of inoculation on physical and chemical parameters,ammonia and hydrogen sulfide release,nitrogen form and sulfur compound content change and physical-chemical properties during nitrogen and sulfur conversion were studied.The results showed that inoculation of TNB and TSOB increased the temperature,pH,OM degradation,C/N ratio and germination index(GI)of compost.Compared with the control treatment(CK),the addition of inoculants reduced the release of NH_(3) and H_(2)S,and transformed them into nitrogen and sulfur compounds,the hydrolysis of polymeric ferrous sulfate was promoted,resulting in relatively high content of sulfite and sulfate.At the same time,the physical and chemical properties of SS have a strong correlation with nitrogen and sulfur compounds.展开更多
Drought stress(DS)and overuse of chemical fertilizers cause considerable losses in the agro-physiological as well as biochemical performance of plants.In this context,considerable effort will be required to replace ch...Drought stress(DS)and overuse of chemical fertilizers cause considerable losses in the agro-physiological as well as biochemical performance of plants.In this context,considerable effort will be required to replace chemical fertilizers(NPK)with biostimulants as an important approach to enhance the productivity and sustainability of agriculture.Here,we evaluated the effect of separating and/or combining arbuscular mycorrhizal fungi(AMF)with compost(C)in comparison to the use of NPK on the growth,physiological and biochemical of tomatoes under DS.The findings showed that DS significantly reduced the growth and physiological attributes of tomatoes.Furthermore,the treatment of AMF and C showed better results in agro-physiological and fruit quality compared to the NPK and control under DS.The combination of AMF and C(C+AMF)increased leaf water potential by 18.8%,stomatal conductance by 14.1%,fresh fruit weight by 25.0%,shoot dry matter by 104%and root dry matter by 56.1%compared to the control under DS.The study revealed that C+AMF caused a significant increase in sugar,protein and activity of polyphenoloxidase and peroxidase in leaves and fruits,and an opposite trend was observed in the case of malonaldehyde and hydrogen peroxide compared to NPK and control under DS.In conclusion,it is recommended to utilize the combination of AMF with compost to enhance the growth,yield,osmotic adjustment,and antioxidant capacity of tomato plants.This approach can boost their resilience to water stress and improve overall fruit quality.展开更多
基金supported by the Major Consulting Research Project of Chinese Academy of Engineering 2019-ZD-33projects from the China Three Gorges Group Co.LTD(No.2020(W)-080,No.202003065)。
文摘Fulvic acid(FA),typical organic matter derived from humification process in composted sludge,possesses the potential to remediate mine soils contaminated by heavy metals.To understand the cooper(Cu)immobilizing process in open-pit mine soil induced by FA,changes of Cu speciation in mixture of open-pit mine soil and composted sludge was tracked over 180 days.It was observed that the organic-bound and residual fraction of Cu increased dramatically with the corresponding decrease of Fe/Mn oxide-bound Cu in the first 60 days,then the organic-bound fraction decreased to about its initial proportion during 60-120 days,while residual fraction still increased,and the proportion of residual Cu accounted for over85%and became stable after 120 days.To reveal the mechanism of FA inducing Cu fixation on Albite which is the main phase of soil primary ore,two groups of Cu adsorption experiments with and without FA were designed.With the addition of FA,the adsorption capacity of Cu by Albite increased by 1.55 times and the content of residual Cu in Albite increased by7.7 times.It was found that the Cu absorbed in smaller Albite particle induced by FA formed a secondary mineral——Chrysocolla,causing increase of residual fraction of Cu.These results revealed the mechanism:FA was absorbed on the surface of Albite after complexing with Cu ions in the solution,and then it induced Cu into the interlayer and pore channels of Albite.The Cu in the Albite was immobilized by forming Chrysocolla finally.
基金supported by the Important Projec of China's Western Development (2004BA901A14)
文摘Plant pesticide residues, such as chinaberry （Melia toosendan） residue and sand cypress （Sabina vulgaris） residue, are pesticidal plant materials discarded after the bioactive ingredient has been extracted with organic solvents. The only option for botanical pesticide residue utilization has been as landfill. Chinaberry residue （CBR） and sand cypress residue （SCR） were collected and composted in Yangling, Shaanxi Province, China. We studied the effects of chinaberry residue compost （CBRC）, CBRC incorporated with Trichoderma viride （CBRCT）, sand cypress residue compost （SCRC）, and SCRC incorporated with T. viride （SCRCv） on the root-knot nematode, Meloidogyne incognita, infesting the balloonflower （Platycodon grandiflorum）. Bioassay results indicated that stock solutions of the CBRCT and SCRCT extracts significantly inhibited egg hatching and caused high larval mortality, followed in degree by the CBRC and SCRC extracts. The CBR and SCR extracts caused very low inhibition of eggs and larvae. Supplementing potting mixtures with these four composts reduced the severity of root galling and increased the proportion of marketable roots. The severity of root galling decreased and the average weight of the marketable roots increased with an increase in all the composts when supplemented at rates from 5 to 30%. CBR- and SCR-supplemented pot soils also inhibited the nematodes, but CBR and SCR applied to the soil had a phytotoxic effect and inhibited balloonflower growth. Supplementing field soil with the composts reduced the severity of root galling and the populations of southern root-knot nematodes in the soil. CBRCT and SCRCT clearly enhanced the average weight of the marketable roots by 30.45 and 26.64%, respectively. Continuous supplementation with CBRCT or SCRCT in the same field significantly enhanced the control of the root-knot nematode, and the populations of nematodes continued to decrease with second inoculations. The populations of total Trichoderma spp. were distinctly enhanced and were maintained at high levels for a long time in the supplemented soils.
文摘Field experiments were conducted to determine the effect of composts prepared from different organic materials with rock phosphate (RP) on yield and P uptake of berseem and their residual effect on maize crop (cv. Azam) during 2011-2012. Composts prepared from RP fed farm yard manure (FYM), simple FYM, organic waste and city garbage were applied at the rate based on their P concentrations. Composts significantly (P ≤ 0.05) increased total dry matter weight of Berseem in first and second cut over control. Residual effect of the prepared composts was determined on yield and plant P uptake of maize in the same layout of Berseem. Maximum and significantly (P ≤ 0.05) higher maize grain yield, total dry matter yield and stover yield of 3161 kg·ha-1, 9633 kg·ha-1 and 6472 kg·ha-1, respectively were recorded by the residual effect of compost of organic waste with half dose of SSP. Thousand grains weight of 220 g was noted in the treatment of residual effect of compost of RP fed FYM with half dose of SSP. Post harvest soil N and P concentrations improved with composting. Significant (P ≤ 0.05) increases in N and P uptake by berseem and maize plants were observed with added composts. Results suggest that the use of composts prepared from different organic materials with RP is environmental friendly and has potential to improve crops yield and plants N and P uptakes for a prolonged time.
文摘In this work the physical, chemical and microbial properties of four locally composted green waste composts (GWCs) namely Almukhasib, Growers, Plantex, and Super along with four imported GWC (Florabella, Mikskaar, Potgrond, and Shamrock) were studied to evaluate the quality of these composts with the acceptable standards. All composts showed normal physical properties, except the bad smell from sulfur reducing bacteria in Almukhasib, light brown color Plantex and one viable weed seed in Shamrock compost. The germination indexes of the composts comparable to the standard (90%) were 100% for Mikskaar, followed by Shamrock (92%), Florabella (97), Potgrond (95%), Plantex (98%), Growers (77%), and 5% for both Super and Almukhasib. The physical and chemical properties vary considerably as follows: pH 3 - 10.5, 5.1 - 6.5 (standard 5 - 8), electrical conductivity (EC) 0.4 - 10.2 mS·cm-1, 0.8 - 1.8 mS·cm-1(standard 0.0 - 4.0 mS·cm-1), moisture content (MC%) 29% - 43.7%, 64% - 74% (standard 35% - 60%) and water holding capacity (WHC%) 92% - 200% and 400% - 800% for the locally produced and imported composts, respectively. Wide ranges in the chemical properties were expressed as ammonia concentration 512.4 - 1640.1 mg·kg-1, 459.4 - 656.5 mg·kg-1(standard -1), organic matter 17% - 67.6%, and 53.3% - 66.2% (standard 35%) for the locally composted and imported composts, respectively. The concentrations of the heavy metals (Zn, Ni, Pb, Hg, As, Cd, and Cr) were lower than the recommended levels. The average of the bacterial colony forming unit per gram of locally produced and imported composts ranged between 260 - 1740 CFU/g and 330 - 2870 CFU/g, whereas the fungal CFU were 10 - 2800 CFU/g and 27 - 1800 CFU/g, respectively. The most probable number (MPN) for coliform bacteria was 43 - 1100 CFU/g for locally produced composts, and 23 - 480 CFU/g for the imported composts. Therefore, these composts can not be used directly without effective treatment as substrate for plant growth, soil amendment and as biofertilizer.
基金Supported by Scientific Research Foundation of Henan Provincial Department of Education(13A180676)
文摘In order to find fermentation starters that can promote rapid and effective composting of chicken manure,shorten the fermentation period,and improve the compost quality,fermentation starters with different microbial combination ratios(C1,C2,C3,C4 and C5) were designed and fermentation experiment was carried out on these five fermentation starters,commercially available organic fertilizer starter(SS),and chicken manure without inoculating fermentation starter. In the process of the fermentation,the changes in the fermentation temperature,water content and pH value were monitored; the effects of organic manure on the germination rate and growth of rapeseed seeds were measured;viable count,water content,and pH value of prepared fermentation starters were measured; main indicators( organic matter,nitrogen,phosphorus,and potassium) of organic fertilizer generated from fermentation were measured. From the indicators,the formula C3 and C4 were better,in the beginning of fermentation,the temperature rose rapidly,and it reached 40 ℃ in the second day; the water content dropped to below 35% in the 18 th day; the pH value underwent the process of declining-rising-stable,and the overall value showed slight rise,but the change was not great( 0-0. 5). C3 and C4 fermentation products had better effects on the germination and growth of rapeseeds. The germination rate of the rapeseed seeds was 100% and 97. 5% and the bud length was 15. 94 mm and 14. 57 mm,respectively,and the root length was45. 97 mm and 39. 44 mm,respectively. The content of organic matter in fermented organic manure was 86. 62% and 85. 17% respectively,and the total content of nitrogen,phosphorus and potassium was 8. 85% and 8. 22% respectively,and the pH was 7. 5 and 8. 0 respectively.All of these complied with the industry standard NY525-2012( organic matter ≥ 45%,and nitrogen,phosphorus,and potassium ≥ 5%,pH 5. 5-8. 5). The fermentation of fresh chicken manure was completed within 20 days,conforming to the requirements of large-scale organic fertilizer production factory for composting chicken manure into organic fertilizer.
文摘Smallholder farming is promoted for its environmental friendliness, assurance of food security sovereignty and conservation of indigenous knowledge. However, in actual practice, Smallholder farmers recycle farm plant waste to improve soil fertility. By so doing, they contribute to environmental pollution, emissions, and global warming. This situation is a Smallholder farmers’ challenge worldwide. One of these challenges is the inability to find cheaper sources of plant nutrients. These sources of nutrients are associated with environmental pollution, such as the release of Methane. This study focused on farm wastes (bean trash, maize trash, banana trash, cattle slurry, goat slurry, and pig slurry) commonly produced by smallholder farmers in two farming systems of Masaka and Lyantonde Districts to explore the effects of composting and surface decomposition on nutrients contained in farm wastes by specifically: estimating baseline nutrient contents in farm wastes before disposal, determining the variation of nutrients of farm wastes managed by composting and surface decomposition and the potential source of major nutrients among selected farm wastes. Through carbon analysis, Calorimetric determination of Nitrogen and Phosphorus analysis using a block digester and UV-Visible spectrometer, Carbon, Nitrogen, Potassium and Phosphorus were determined from bean trash, maize trash, banana trash, cattle slurry, goat slurry, and pig slurry. Results revealed that goat slurry, chicken waste, maize trash and pig slurry contained more and retained more P, K, C and N, respectively, as compared to other farm wastes. Significant volumes of N and P were retained in composted materials as compared to those managed by surface decomposition.
文摘The potential use ofcomposted wood fibre waste （WFW） for the cultivation of bacterial antagonists of Sclerotinia minor was examined with the result that a mix of millet seed （20% w/w） and WFW, suitably amended with nutrients, proved to be an ideal matrix for the growth of some of these bacteria. Densities in terms ofcfu＇s ranged from 8.5 IOgl0 cfu/g dw to 10.5 logl0 cfu/g dw ullder sterile conditions after 14 days incubation. Lower population densities of the antagonists were achieved under non-sterile conditions in the compost： millet mix of between 7.9-9.3 logm cfu/g dw at the same period. However, when applied in a pot （glasshouse） trial to protect against S. minor, the millet seed appeared to stimulate the growth of this pathogen resulting in a high incidence of attack of lettuce plants after 2-3 weeks. Although the percentage of healthy seedlings increased following application of compost mix grown antagonists （at a rate of 5% v/v） when compared to the control treatment, these values were not statistically significant （p〉0.05） in most cases. Therefore, the use of millet seeds cannot be recommended as a nutrient supplement for the bacterial antagonist cultivation, if to be subsequently used to control fungal pathogens in the field.
文摘Biochar is widely recognized as an amendment that enhances soil properties and sequesters carbon,particularly in degraded soils.However,biochar applied solely to soil may also hinder plant development due to toxic by-products generated during pyrolysis or nutrient retention.To mitigate these adverse effects,it has been suggested to either mix biochar with compost or to process it by composting with fresh organic materials.To date,there is a lack of comparative studies evaluating the performance of these two approaches.In this study,three types of biochar,differing in their initial feedstocks(beech wood,hornbeam/beech/oak mixture,and digestate/cereal straw mixture),were investigated.These biochars were applied solely,mixed with green waste compost,or processed as composted biochar in two soils of different fertility(a Luvisol and a gleyic Fluvisol).A pot experiment was conducted under controlled conditions where lettuce was grown for three months.After harvesting,plant biomass,and soil microbial and physicochemical properties were measured.Composted biochar and compost additives maintained a neutral soil pH,contrary to biochar applied solely or mixed with compost.The dissolved organic carbon and total nitrogen were higher in composted biochar treatments,leading to a higher proportion of humified material with a high degree of condensed aromatic groups compared to other treatments.Microbial activities were higher in the composted biochar treatments compared to those in the compost with biochar,and more specifically in the less fertile Luvisol.Finally,composted biochar increased plant growth by almost six times compared to the control without amendments,whereas the mix of biochar and compost increased it by only three times.Solely applied biochars did not affect lettuce growth.This study demonstrates that biochar composting is more beneficial than mixing biochar with compost in terms of improving soil fertility and mitigating the negative effects associated with pure biochar application.
基金supported by the Tropical and Subtropical Agriculture Research(T-STAR)' and funded by the USDA-NIFA.
文摘The purpose of this study was to quantify the release of nitrate into vadose zone as well as the nitrogen-holding capacity of compost applied on calcareous soils of northern Guam amended with both inorganic fertilizer and composted organic waste,to examine potentially adverse effect of these nutrient materials to groundwater quality.Three different nitrogen levels each of the composted organic waste and the inorganic fertilizer were applied to corn(maize)(farmland)study plots for three consecutive seasons,two dry and one rainy season.During each season,soil organic matter(SOM,w/w%)content and carbon-nitrogen ratio(C/N,w/w%),were determined for analysis of the nitrogen-holding capacity of these calcareous soils.Nitrate levels in soil pore water were also determined for study of potential groundwater contamination.For three seasons,compost plots showed higher SOM%contents and lower C/N%than fertilizer plots.That is,compost-treated soils showed higher SOM content and adsorbed more nitrogen under normalized soil mass than did fertilizer-treated soils.Nitrate levels in pore water were generally higher on compost plots during early stages of corn but were generally higher on fertilizer plots during active leaf,tasseling,and maturity stages.During the rainy season,nitrate leachate seemed to increase,but this trend could not be confirmed because rainfall amounts were not measured.Overall,composted organic waste proved to be a good amendment for soil productivity and agricultural sustainability while reducing nitrate leachate from northern Guam farmland.
文摘The fact that Morocco is an agricultural country and the large volume of biodegradable waste produced by the population make composting so important.The degradation of organic matter is facilitated by faunal and floral macro and micro-organisms that act in different stages of maturation;studies on this fauna are quite rare both nationally and internationally.On a sample of two tons of household waste,we documented invertebrates that colonized compost heaps and then assessed the changes in the structure of the invertebrate population during the different phases.Our study revealed the presence of several zoological groups colonizing the compost heaps during the different composting phases;we noted the presence of:(1)Macroscopic invertebrates,in order of number of individuals:insect larvae,ants,earthworms,sowbugs,spiders,springtails,and millipedes,and(2)Microscopic invertebrates,the most abundant in terms of individuals:mites and nematodes.As for the order of appearance,we observed that insect larvae were the first to colonize the compost heap from the very first days of installation,followed by woodlice observed during the thermophilic phase and disappearing towards the end of the process.Earthworms were observed during the end of the thermophilic phase,while springtails were observed more during the cooling and maturation phases.Our study revealed the presence of a good quality of fauna during the composting process,which are indicators of good compost quality and play a major role in the circulation of nutrients,thus ensuring the provision of essential elements for plant nutrition.
文摘Enhancing A.bisporus L.culture media with nanomaterials and some biostimulants is important for in improving mushroom productivity quantitatively and qualitatively.Magnetic iron nanoparticles(N-FeO),carbon nanotube(CNTs)suspensions,effective microorganisms(EM)bio-fertilisers,and growth stimulants(Atonik)were used individually and in combination to enhance the compost culture media.Quantitative and qualitative traits of the mushroom yield were measured.In a simple oOne-Wway experiment that included 16 treatments—Ssingle agents,two-,three-,and four-way Ccombinations and three replications—,the statistical analysis results of Duncan’'s test showed.Tthat the individual impact of the applied study treatments and their combined synergistic effects resulted in a significant increase in the traits of the number of fruiting bodies,fruiting body rate,yield quantity,mushroom biological efficiency ratio,stem length,stem diameter,head diameter,head thickness,carbohydrates content,protein content,ash,and dry matter.The application of Atonik itself resulted in the highest values of fruiting body number,yield,biological efficiency,and stem length,which were respectively were 128.33 body bags^(-1),2814 g bag-1,37.52%,and 3.03 cm,compared to the control of 32.33 body bags^(-1),749 g bag-1,9.98%,and 1.72 cm.The treatments NFeO+CNT+EM+ATO resulted in a significant increase in the traits of the fruiting body rate,stem length,and carbohydrate content by 32.69 g,3.40 cm,and 16.78%,respectively,compared to the control of 22.97 g,1.72 cm,and 8.16%,respectively.
文摘Rice straw,which is produced after the harvest of rice,is a major agricultural waste in the world.Rice straw has a high carbon/nitrogen ratio and is more resistant to microbial degradation than other straws because its main constituents are cellulose and hemicelluloses encrusted by lignin.When rice straw is burned,hazardous substances such as carbon dioxide,methane,carbon monoxide,and nitrogen monoxide are released into the air as smoke(less than 10μm-sized particles).The rise in the burning of rice straw has contributed to too many accidents and health issues in the general population residing in Haryana,Punjab,and Uttar Pradesh of India.These states are being urged by the National Green Tribunal to generate money instead of burning rice straw.Even though these lignocellulosic materials might be beneficial,not much has been carried out with them.This overview covers the properties of rice straw and husks,the numerous procedures used to create valuable products,and various applications that may be made for them.These include energy sources,environmental adsorbents,building supplies,and specialist commodities.
文摘Although the efficiency of poly(ethylene terephthalate)(PET)degradation has been successfully improved by depolymerase engineering,mostly by using Goodfellow-PET(gf-PET)as a substrate,efforts to degrade unpretreated PET materials with high crystallinity remain insufficient.Here,we endeavored to improve the degradation capability of a WCCG mutant of leaf-branch compost cutinase(LCC)on a unpretreated PET substrate(crystallinity>40%)by employing iterative saturation mutagenesis.Using this method,we developed a high-throughput screening strategy appropriate for unpretreated substrates.Through extensive screening of residues around the substrate-binding groove,two variants,WCCG-sup1 and WCCG-sup2,showed good depolymerization capabilities with both high-(42%)and low-crystallinity(9%)substrates.The WCCG-sup1 variant completely depolymerized a commercial unpretreated PET product in 36 h at 72℃.In addition to enzyme thermostability and catalytic efficiency,the adsorption of enzymes onto substrates plays an important role in PET degradation.This study provides valuable insights into the structure-function relationship of LCC.
基金supported by the Science and Technology Innovation Special Fund Project of Fujian Agriculture and Forestry University (No.CXZX2020073A)Project of Fujian Provincial Department of Science and Technology,China (No.2022N5007)。
文摘This study explored the combined effects of Bacillus subtilis inoculation with biochar on the evolution of bacterial communities,antibiotic resistance genes(ARGs),and mobile genetic elements(MGEs)during the composting of chicken manure.The results showed that B.subtilis inoculation combined with biochar increased bacterial abundance and diversity as well as prolonged the compost thermophilic period.Promoted organic matter biodegradation and facilitated the organic waste compost humification process,reduced the proliferation of ARGs by altering the bacterial composition.Firmicutes and Actinobacteriota were the main resistant bacteria related to ARGs and MGEs.The decrease in ARGs and MGEs was associated with the reduction in the abundance of related host bacteria.Compost inoculation with B.subtilis and the addition of biochar could promote nutrient transformation,reduce the increase in ARGs and MGEs,and increase the abundance of beneficial soil taxa.
基金supported by the Open Research Fund Program of State Environmental Protection Key Laboratory of Food Chain Pollution Control(No.FC2022YB01)the National Natural Science Foundation of China(No.32071552)+1 种基金the Independent Research Project of Science and Technology Innovation Base in Tibet Autonomous Region(No.XZ2022JR0007G)China Agricultural University-Dabeinong Group Professional degree graduate joint training reform project(No.CAUDBN PDG-JTRP).
文摘Microbial activity and interaction are the important driving factors in the start-up phase of food waste composting at low temperature.The aim of this study was to explore the effect of inoculating Bacillus licheniformis on the degradation of organic components and the potential microbe-driven mechanism from the aspects of organic matter degradation,enzyme activity,microbial community interaction,and microbial metabolic function.The results showed that after inoculating B.licheniformis,temperature increased to 47.8℃ on day2,and the degradation of readily degraded carbohydrates(RDC)increased by 31.2%,and the bioheat production increased by 16.5%.There was an obvious enhancement of extracellular enzymes activities after inoculation,especially amylase activity,which increased by 7.68 times on day 4.The inoculated B.licheniformis colonized in composting as key genus in the start-up phase.Modular network analysis and Mantel test indicated that inoculation drove the cooperation between microbial network modules who were responsible for various organic components(RDC,lipid,protein,and lignocellulose)degradation in the start-up phase.Metabolic function prediction suggested that carbohydrate metabolisms including starch and sucrose metabolism,glycolysis/gluconeogenesis,pyruvate metabolism,etc.,were improved by increasing the abundance of related functional genes after inoculation.In conclusion,inoculating B.licheniformis accelerated organic degradation by driving the cooperation between microbial network modules and enhancing microbial metabolism in the start-up phase of composting.
基金financially supported by the National Key Research and Development Program of China(Nos.2022YFE0119100 and 2017YFE0198000)the National Natural Science Foundation of China(Nos.U21A2054,52273285,52061009 and 52262032)Guangxi Science and Technology Planning Project(No.AD21220056)。
文摘SiGe-based thermoelectric(TE)materials have gained increasing interests due to their low maintenance costs,environmental friendliness and long lifespan.However,the intrinsically high thermal conductivity of Si-based materials also results in poor TE properties.In this investigation,a zirconia(ZrO_(2))composite strategy was applied to an n-type SiGe alloy,tremendously elevating its TE performance.After mechanical alloying and spark plasma sintering(SPS)processes,the ZrO_(2)induced the formation of nanopores in the SiGe matrix via phosphorus adsorption.Moreover,such increase in porosity enhanced the phonon scattering and dramatically suppressed lattice thermal conductivity,from 2.83 to 1.59 W·m^(-1)·K^(-1)at 873 K.Additionally,reduced phosphorus doping led to an increase in Seebeck coefficients and a relatively minor decrease in electrical conductivity,The power factor didn't deteriorate significantly,either,as its maximum of~3.43 mW·m^(-1-)K^(-2)was achieved at 873 K with(Si_(0.8)Ge_(0.2))_(0.097)P_(0.03)(ZrO_(2))_(0.003).In short,a peak figure of merit(ZT)of~1.27 at 873 K and an average ZT~0.7 from 323 to 873 K were obtained.This study demonstrates that the electrical and thermal transportation of SiGe material can be synergistically tuned by compositing ZrO_(2),illustrating a novel strategy to optimize the TE properties of bulk materials.
基金supported by the National Natural Science Foundation of China(Nos.32071552,42007031,31960013,and 31800378)the Open Research Fund from the Key Laboratory of Forest Ecology in Tibet Plateau(Tibet Agriculture&Animal Husbandry University),Ministry of Education,China(No.XZAJYBSYS-2020-02)+2 种基金the Independent Research Project of Science and Technology Innovation Base in Tibet Autonomous Region(No.XZ2022JR0007G)Suzhou Science and Technology Plan Project(No.SS20200)Ministry of Urban-Rural Development and Housing Technology Demonstration Project(No.S20220395)。
文摘Additives could improve composting performance and reduce gaseous emission,but few studies have explored the synergistic of additives on H_(2)S emission and compost maturity.This research aims to make an investigation about the effects of chemical additives and mature compost on H_(2)S emission and compost maturity of kitchen waste composting.The results showed that additives increased the germination index value and H_(2)S emission reduction over 15 days and the treatment with both chemical additives and mature compost achieved highest germination index value and H_(2)S emission reduction(85%).Except for the treatment with only chemical additives,the total sulfur content increased during the kitchen waste composting.The proportion of effective sulfur was higher with the addition of chemical additives,compared with other groups.The relative abundance of H_(2)S-formation bacterial(Desulfovibrio)was reduced and the relative abundance of bacterial(Pseudomonas and Paracoccus),which could convert sulfur-containing substances and H_(2)S to sulfate was improved with additives.In the composting process with both chemical additives and mature compost,the relative abundance of Desulfovibrio was lowest,while the relative abundance of Pseudomonas and Paracoccus was highest.Taken together,the chemical additives and mature compost achieved H_(2)S emission reduction by regulating the dynamics of microbial community.
基金This work was supported by the National Natural Science Foundation of China(No.42030704).
文摘Composting presents a viable management solution for lignocellulose-rich municipal solid waste.However,our understanding about the microbial metabolic mechanisms involved in the biodegradation of lignocellulose,particularly in industrial-scale composting plants,remains limited.This study employed metaproteomics to compare the impact of upgrading from aerated static pile(ASP)to agitated bed(AB)systems on physicochemical parameters,lignocellulose biodegradation,and microbial metabolic pathways during largescale biowaste composting process,marking the first investigation of its kind.The degradation rates of lignocellulose including cellulose,hemicellulose,and lignin were significantly higher in AB(8.21%-32.54%,10.21%-39.41%,and 6.21%-26.78%)than those(5.72%-23.15%,7.01%-33.26%,and 4.79%-19.76%)in ASP at three thermal stages,respectively.The AB system in comparison to ASP increased the carbohydrate-active enzymes(CAZymes)abundance and production of the three essential enzymes required for lignocellulose decomposition involving a mixture of bacteria and fungi(i.e.,Actinobacteria,Bacilli,Sordariomycetes and Eurotiomycetes).Conversely,ASP primarily produced exoglucanase andβ-glucosidase via fungi(i.e.,Ascomycota).Moreover,AB effectively mitigated microbial stress caused by acetic acid accumulation by regulating the key enzymes involved in acetate conversion,including acetyl-coenzyme A synthetase and acetate kinase.Overall,the AB upgraded from ASP facilitated the lignocellulose degradation and fostered more diverse functional microbial communities in large-scale composting.Our findings offer a valuable scientific basis to guide the engineering feasibility and environmental sustainability for large-scale industrial composting plants for treating lignocellulose-rich waste.These findings have important implications for establishing green sustainable development models(e.g.,a circular economy based onmaterial recovery)and for achieving sustainable development goals.
基金This work was supported by the Wild Goose Array Special Projects(No.2023STYZ002)Heilongjiang Provincial Research Institute Project(Nos.2023SSKY001 and 2022SSKY003).
文摘In this study,high temperature thermotolerant nitrifying bacteria(TNB)and high temperature thermotolerant sulfide oxidizing bacteria(TSOB)were obtained from compost samples and inoculated into sewage sludge(SS)compost.The effects of inoculation on physical and chemical parameters,ammonia and hydrogen sulfide release,nitrogen form and sulfur compound content change and physical-chemical properties during nitrogen and sulfur conversion were studied.The results showed that inoculation of TNB and TSOB increased the temperature,pH,OM degradation,C/N ratio and germination index(GI)of compost.Compared with the control treatment(CK),the addition of inoculants reduced the release of NH_(3) and H_(2)S,and transformed them into nitrogen and sulfur compounds,the hydrolysis of polymeric ferrous sulfate was promoted,resulting in relatively high content of sulfite and sulfate.At the same time,the physical and chemical properties of SS have a strong correlation with nitrogen and sulfur compounds.
文摘Drought stress(DS)and overuse of chemical fertilizers cause considerable losses in the agro-physiological as well as biochemical performance of plants.In this context,considerable effort will be required to replace chemical fertilizers(NPK)with biostimulants as an important approach to enhance the productivity and sustainability of agriculture.Here,we evaluated the effect of separating and/or combining arbuscular mycorrhizal fungi(AMF)with compost(C)in comparison to the use of NPK on the growth,physiological and biochemical of tomatoes under DS.The findings showed that DS significantly reduced the growth and physiological attributes of tomatoes.Furthermore,the treatment of AMF and C showed better results in agro-physiological and fruit quality compared to the NPK and control under DS.The combination of AMF and C(C+AMF)increased leaf water potential by 18.8%,stomatal conductance by 14.1%,fresh fruit weight by 25.0%,shoot dry matter by 104%and root dry matter by 56.1%compared to the control under DS.The study revealed that C+AMF caused a significant increase in sugar,protein and activity of polyphenoloxidase and peroxidase in leaves and fruits,and an opposite trend was observed in the case of malonaldehyde and hydrogen peroxide compared to NPK and control under DS.In conclusion,it is recommended to utilize the combination of AMF with compost to enhance the growth,yield,osmotic adjustment,and antioxidant capacity of tomato plants.This approach can boost their resilience to water stress and improve overall fruit quality.
