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 composition of paper cups creates a challenge for the recycling industry,as the paperboard–plastic film composite is hard to separate.Therefore,paper cups are sent to landfills or waste incinerators.This study ex...The composition of paper cups creates a challenge for the recycling industry,as the paperboard–plastic film composite is hard to separate.Therefore,paper cups are sent to landfills or waste incinerators.This study explores the combined use of red worms(Eisenia fetida)and Greater wax moth(Galleria mellonella)in the biodegradation of paper cups.The study investigates the conditions and combinations that promote using Eisenia fetida and Galleria mellonella for degrading paper cups.The study considered the influence of environmental temperature,the presence of food waste,varying the number of Eisenia fetida worms,and the presence of a Galleria mellonella growth-slowing agent on the degradation process.To achieve the study objectives,the study followed a quantitative approach.The study monitored the degradation of paper cup cuts that were placed in jars containing different combinations of Eisenia fetida worms,Galleria mellonella larvae,food waste,bedding material,and Galleria mellonella growth-slowing agents.The study found that the best operating temperature is 30oC.The study found that using food waste improves the performance of Eisenia fetida worms and Galleria mellonella larvae significantly.The study found that adding a Galleria mellonella growth-slowing agent slightly enhances the degradation of the paper cup.Finally,a numerical model was obtained to simulate the paper cup degradation efficiency.展开更多
A vacuum membrane distillation(VMD)process with permeate fractional condensation on membrane downstream has been developed for simultaneous recovery of phosphorus and nitrogen from liquid digestate.The polytetrafluoro...A vacuum membrane distillation(VMD)process with permeate fractional condensation on membrane downstream has been developed for simultaneous recovery of phosphorus and nitrogen from liquid digestate.The polytetrafluoroethylene(PTFE)membrane flux could reach 6000 g·m-2·h-1 with the rejection efficiency of total phosphorus(TP)over 0.99,under the condition of flowrate being 120 L·h-1 and temperature being 40°C.Membrane fouling occurred with a film of organics and microorganism deposited on the surface of the membrane.Membrane flux could be reversed after the membrane was rinsed by water.Higher feed temperature and flowrate could improve the membrane flux,while hardly affect the rejection efficiency of total phosphorus.The concentration of TP could reach 1600 mg·L-1 after membrane distillation,which is about 5 times of that in initial liquid digestate.On the downstream of the membrane,some of the permeate vapor was condensed under the vacuum condition and most of water was collected here.The remaining vapor enriched with total nitrogen(TN)was compressed and pumped to the atmospheric condition to condense.The TN concentration in atmospheric condensate was as high as 7000 mg·L-1 with the process separation factor for ammonia being enhanced to 114.展开更多
Ecological compensation is widely considered a policy that encourages farmers to recycle livestock and poultry waste for economic and ecological benefits.Therefore,based on field data from 30 counties(districts)in six...Ecological compensation is widely considered a policy that encourages farmers to recycle livestock and poultry waste for economic and ecological benefits.Therefore,based on field data from 30 counties(districts)in six cities of Shandong Province,China,this study systematically analyzes farmers'willingness to accept compensation for livestock and poultry waste resource utilization as well as its determinants.It does so using the UTAUT theoretical analysis framework,as well as the contingent valuation method and Heckman two-stage selection model.The results show that,first,72.4%of the farmers in the sample are willing to accept a certain amount of compensation—the expected value of which is RMB 98.02 per month per household—as an incentive to utilize livestock waste.Second,the key determinants of farmers'willingness to accept compensation are marital status,family annual income,concurrent business,farming scale,economic performance expectation,social performance expectation,knowledge reserve,public relations,and technical convenience.Finally,the factors that affect farmers’willingness in terms of the compensation amount are gender,age,family annual income,social performance expectation,subjective norms,and public relations.Therefore,to promote the recycling of livestock and poultry waste,this study proposes policies that promote education and technology popularization in relation to livestock and poultry waste resource utilization,provide subsidies for waste recycling,and strengthen government control and social supervision over the non-standard disposal of such waste.展开更多
Based on field research data on farmers in 30 counties(districts)of six cities in Shandong Province,this study systematically examines the methods of disposal of livestock and poultry waste and the factors that influe...Based on field research data on farmers in 30 counties(districts)of six cities in Shandong Province,this study systematically examines the methods of disposal of livestock and poultry waste and the factors that influence them,that is,the determinants of farmers’waste disposal behaviors,using the UTAUT theoretical framework and a disordered multi-class logit model.The results show that,first,economic performance expectancy,subjective norms,farming population,and poultry and livestock breeding numbers have significant effects on the four waste recycling methods considered:direct return,compost fermentation,biogas fermentation,and fresh-packed sale.Second,annual family income has a positive effect on the direct return method.Third,compost fermentation is positively affected by farmers'knowledge,distance from sources of water,and farming scale,and negatively affected by gender and marital status.Fourth,biogas fermentation is negatively affected by the age of farmers and positively affected by the farming income ratio and environmental convenience.Finally,the most important factors affecting the four methods are subjective norms,farming scale,economic performance expectancy,and farming population.Therefore,this study proposes that policies to promote resource utilization of livestock and poultry waste must prioritize raising awareness among the farmers of the advantages of resource disposal of waste;provide reasonable subsidies for waste recycling and enhance policy applicability,pertinence,and motivation;strengthen the promotion of waste recycling technology and improve the practicality of lectures or training content;and improve relevant laws and regulations and enhance authority and usability.展开更多
In order to recover the strip pillar coal resources, reduce the amount of gangue mountain and realize remediation of the goaf environment in the old mining area, the raw gangue filling mining technology was proposed. ...In order to recover the strip pillar coal resources, reduce the amount of gangue mountain and realize remediation of the goaf environment in the old mining area, the raw gangue filling mining technology was proposed. According to the previous practical experience, the feasibility of the implementation of raw gangue filling mining technology in the coal-pressed area was analyzed. Through the filling gangue compaction test, the deformation under different loading stages was obtained. Further, a reasonable prediction of the deformation beyond the experimental limited loading load was made based on the experimental results. Through the deformation source analysis of the whole process of gangue filling, the key factors for controlling deformation before, during, and after filling were determined. Additionally, the proportion of deformation during different stages was quantified. Considering the protection of surface buildings, mining fullness of the working face and mining technology, the production parameters of 1209 and 1210 filling working faces were preliminarily determined. Through numerical simulation, the rationality of mining scheme was verified. Based on the practice of 1209 working face and the key factors to control the deformation of gangue filling, the mining system and process in 1210 working face were optimized. According to the measured surface rock movement, raw gangue filling mining technology can meet the requirements of surface building protection level. Especially, this paper provides a method to quantitatively calculate the equivalent mining height (EMH) of raw gangue filling and its mining deformation, which has reference significance for old mining areas.展开更多
Carbonate reservoirs generally achieved relatively low primary resource recovery rates.It is therefore often necessary to clean those reservoirs up and/or stimulate them post drilling and later in their production lif...Carbonate reservoirs generally achieved relatively low primary resource recovery rates.It is therefore often necessary to clean those reservoirs up and/or stimulate them post drilling and later in their production life.A common and basic carbonate reservoir cleanup technique to remove contaminating material from the wellbore is acidizing.The efficiency of acid treatments is determined by many factors,including:the type and quantity of the acid used;the number of repeated treatments performed,heterogeneity of the reservoir,water cut of the reservoir fluids,and presence of idle zones and interlayers.Post-treatment production performance of such reservoirs frequently does not meet design expectations.There is therefore much scope to improve acidizing technologies and treatment designs to make them more reliable and effective.This review considers acid treatment technologies applied to carbonate reservoirs at the laboratory scale and in field-scale applications.The range of acid treatment techniques commonly applied are compared.Differences between specific acid treatments,such as foamed acids,acid emulsions,gelled and thickened acid systems,targeted acid treatments,and acid hydraulic fracturing are described in terms of the positive and negative influences they have on carbonate oil production rates and recovery.Opportunities to improve acid treatment techniques are identified,particularly those involving the deployment of nanoparticles(NPs).Due consideration is also given to the potential environmental impacts associated with carbonate reservoir acid treatment.Recommendations are made regarding the future research required to overcome the remaining challenges pertaining to acid treatment applications.展开更多
Given the conditions of residual coal from the boundary of a flat dipping open-pit mine,which uses strip areas mining and inner dumping with slope-covering,we propose an open-pit and underground integrated mining tech...Given the conditions of residual coal from the boundary of a flat dipping open-pit mine,which uses strip areas mining and inner dumping with slope-covering,we propose an open-pit and underground integrated mining technology for residual coal of end slopes.In the proposal a conveyance road and ventilation conveyance near the slope are built,corresponding to the pit mining area and the surface coal mine dump,as well as an interval haulage tunnel and air-inlet tunnel.The outcome shows that such mining method may reduce the effect to slope stability from underground mining,it does not affect the dumping advance and has a high recovery rate of residual coal resources.The working face is timbered by single hydraulic props,transported by a scraper conveyor and supported by coal walls.This method of mining is one of layered top coal caving,with high resource recovery,low production cost where positive economic benefit can be realized.展开更多
Absence of wastewater and solid waste facilities impacts the quality of life of many people in developing countries. Implementation of these facilities will benefit public health, water quality, livelihoods and proper...Absence of wastewater and solid waste facilities impacts the quality of life of many people in developing countries. Implementation of these facilities will benefit public health, water quality, livelihoods and property value. Additional benefits may result from the potential recovery of valuable resources from wastewater and solid waste, such as compost, energy, phosphorus, plastics and paper. Improving water quality through implementation of wastewater and solid waste interventions requires, among others, an analysis of i) sources of pollution, ii) mitigating measures and resource recovery potentials and their effect on water quality and health, and iii) benefits and costs of interventions. We present an integrated approach to evaluate costs and benefits of domestic and industrial wastewater and solid waste interventions. To support a policy maker in formulating a cost and environmentally effective approach, we quantified the impact of these interventions on 1) water quality improvement, 2) resource recovery potential, and 3) monetized benefits versus costs. The integration of technical, hydrological, agronomical and socio-economic elements to derive these three tangible outputs in a joint approach is a novelty. The approach is demonstrated using the heavily polluted Indonesian Upper Citarum River in the Bandung region. Domestic interventions, applying simple (anaerobic filter) technologies, were economically most attractive with a benefit cost ratio (BCR) of 3.2, but could not reach target water quality standards. To approach the target water quality, both advanced domestic (nutrient removal systems) and industrial wastewater treatment interventions were required, leading to a BCR of 2. We showed that benefits from selling recovered resources represent here an additional driver for improving water quality and outweigh the additional costs for resource recovery facilities. While included benefits captured some of the major items, these may have been undervalued. Based on these findings, water quality interventions justify their costs and are socially and economically beneficial.展开更多
Carbon cycle regulation and greenhouse gas(GHG)emission abatement within wastewater treatment plants(WWTPs)can theoretically improve sustainability.Currently,however,large amounts of external carbon sources used for d...Carbon cycle regulation and greenhouse gas(GHG)emission abatement within wastewater treatment plants(WWTPs)can theoretically improve sustainability.Currently,however,large amounts of external carbon sources used for deep nitrogen removal and waste sludge disposal aggravate the carbon footprint of most WWTPs.In this pilot-scale study,considerable carbon was preliminarily recovered from primary sludge(PS)through short-term(five days)acidogenic fermentation and subsequently utilized on-site for denitrification in a wool processing industrialWWTP.The recovered sludge-derived carbon sources were excellent electron donors that could be used as additional carbon supplements for commercial glucose to enhance denitrification.Additionally,improvements in carbon and nitrogen flow further contributed to GHG emission abatement.Overall,a 9.1%reduction in sludge volatile solids was achieved from carbon recovery,which offset 57.4%of external carbon sources,and the indirect GHG emissions of the target industrial WWTP were reduced by 8.05%.This study demonstrates that optimizing the allocation of carbon mass flow within a WWTP has numerous benefits.展开更多
The resource recovery of heavy metals from effluent has significant environmental implications and potential commercial value.Chromium phosphide nanoparticles embedded in a nitrogen-/phosphorus-doped porous carbon mat...The resource recovery of heavy metals from effluent has significant environmental implications and potential commercial value.Chromium phosphide nanoparticles embedded in a nitrogen-/phosphorus-doped porous carbon matrix(CrP/NPC)are synthesized via a consecutive Cr^(6+)leachate treatment and resource recovery process.Electrochemical testing shows that CrP/NPC shows excellent nitrogen reduction reaction(NRR)performance,which yields the highest NH_(3) production rate of 22.56μg h^(−1) mg^(−1)_(cat).and Faradaic efficiency(16.37%)at−0.5 V versus the reversible hydrogen electrode in a 0.05M Na_(2)SO_(4) aqueous solution,as well as robust catalytic stability.The isotopic experiments using ^(15)N^(2) as a nitrogen source confirm that the detected NH_(3) is derived from the NRR process.Finally,density functional theory(DFT)calculations show that the electron deficiency environment of the Cr site can significantly reduce the barrier of the NRR process and promote the formation of intermediate species.展开更多
Red mud is a byproduct of alumina refining of bauxite ores,and is a significant source for extracting scandium.However,a large amount of iron in red mud makes it difficult to recover scandium because Fe(III) and Sc(Ⅲ...Red mud is a byproduct of alumina refining of bauxite ores,and is a significant source for extracting scandium.However,a large amount of iron in red mud makes it difficult to recover scandium because Fe(III) and Sc(Ⅲ) have similar physicochemical properties.In this study,a new method was developed for selective separation of iron and scandium in acid leachate of red mud using D201 resin.Theoretical calculations indicate that the ferric species mainly exists as FeCl3 or FeCl4-at chloride concentration above 6.65 mol/L,while scandium still exists as SCl2+,making it possible to selectively separate iron fro m scandium through anion resin adso rption.The factors affecting the adso rption of iron and scandium such as chloride conce ntratio n,resin dosage,adso rption time,and temperature were evaluated in batch experiments,The Langmuir model was successfully applied to both iron and scandium adsorption,and the maximum adsorption capacities of iron and scandium are 147.06 and 0.95 mg/g,respectively,indicating a significant difference between iron and scandium.Raman analysis further demonstrates that the iron is adsorbed onto D201 resin as FeCl4 anion.展开更多
Wastewaters from various process industries,namely food and agricultural,sugar mill,brewery,milk,vegetable and fruit,and meat and fsheries processing industries and their wastewater efuents contain nutrients,organic m...Wastewaters from various process industries,namely food and agricultural,sugar mill,brewery,milk,vegetable and fruit,and meat and fsheries processing industries and their wastewater efuents contain nutrients,organic matter,inorganic,heavy metals,suspended solids,and pathogens.The discharges of non-treated wastewater enter the nearby aquatic ecosystem(e.g.,lakes,rivers)and are a signifcant concern due to the presence of diferent nutrients,competing ions and C containing pollutants.It causes excessive growth of algae,loss of habitat/species,and other negative impacts on human health/environment.In the present review,diferent treatment approaches have been discussed in utilizing these nutrients to synthesize value-added products such as biopolymer,biofuel,pigment,organic acid,or enzymes.These biopolymers can be used to prepare various food products/packaging materials.Dextran,chitosan,carrageenan,alginate,and pectin are good examples of non-food biopolymers.Besides these products,poly-β-hydroxybutyrate(PHB)synthesis from wastewater nutrients is reported as a new source of bio-nanocomposite materials/biopolymer-based coatings.In this review,the diferent treatment approaches are discussed,which are being used worldwide for the removal/recovery of nutrients,toxic pollutants,and the potential resource recovery of value-added products from wastewater.展开更多
The increasing amount of food waste from various industrial,agricultural,and household sources is an environmental burden if managed inappropriately.Numerous waste management approaches have been developed for the dis...The increasing amount of food waste from various industrial,agricultural,and household sources is an environmental burden if managed inappropriately.Numerous waste management approaches have been developed for the disposal of food waste,but still suffer from either high cost,production of toxic by-products,or secondary environmental pollutions.Herein,we report a new and sustainable plasma electrolysis biorefinery route for the rapid and efficient liquefaction of food waste.During the plasma electrolysis process,only the solvent is added to liquefy the waste,and anions in the waste can contribute to catalyzing the biowaste conversion.While liquefying the waste,the highly reactive species produced in the plasma electrolysis process can efficiently reduce the content of O,N,and Cl in the liquefied products and oxidize most of the metals into solid residues.Especially,the removal rate of Na and K elements was greater than 81%,which is significantly higher than using the traditional oil bath liquefaction,resulting in a relatively high-quality biocrude oil with a high heating value of 25.86 MJ·kg^(-1).Overall,this proposed strategy may provide a new sustainable and eco-friendly avenue for the power-to-chemicals valorization of food waste under benign conditions.展开更多
This study reports the feasibility of using municipal wastewater biosolids as an alternative carbon source for biological phosphorus removal.The biosolids were treated by a lowtemperature,thermal alkaline hydrolysis p...This study reports the feasibility of using municipal wastewater biosolids as an alternative carbon source for biological phosphorus removal.The biosolids were treated by a lowtemperature,thermal alkaline hydrolysis process patented by Lystek International Inc.(Cambridge,ON,Canada)to produce short-chain volatile fatty acids and other readily biodegradable organics.Two sequencing batch reactors(SBRs)were operated with synthetic volatile fatty acids(Syn VFA)and readily biodegradable organics produced from the alkaline hydrolysis of municipal wastewater biosolids(Lystek)as the carbon source,respectively.Municipal wastewaters with different strengths and COD:N:P ratios were tested in the study.The reactors’performances were compared with respect to nitrogen and phosphorus removal.It was observed that phosphorus removal efficiencies were between 98%–99%and 90%–97%and nitrogen removal efficiencies were 78%–81%,and 67%for the Syn VFA and Lystek,respectively.However,the kinetics for phosphorus release and uptake during the anaerobic and aerobic stages with Lystek were observed to be significantly lower than Syn VFA due to the presence of higher order VFAs(C4 and above)and other fermentable organics in the Lystek.展开更多
Ammonium sorption and recovery processes typically take place in conventional packed columns,with a configuration that enables maximum sorption by the sorbents.However,batch or semi-continuous operations in packed col...Ammonium sorption and recovery processes typically take place in conventional packed columns,with a configuration that enables maximum sorption by the sorbents.However,batch or semi-continuous operations in packed columns have associated issues such as scaling and frequent backwashing requirements,which are economically prohibitive.As an alternative,ammonium sorption could occur in well-mixed continuously stirred tanks,which would allow for the ammonium sorption process to be retrofitted in existing wastewater treatment plants,provided that efficient sorbent separation can be achieved.This study demonstrates,for the first time,the preparation of magnetic poly(acrylic acid)-based(PAA)ammonium sorbents through the incorporation of magnetic(Fe_(3)O_(4))nanoparticles(MNP)produced via scalable and cost-effective electrochemical synthesis.The MNP and PAA hydrogels were synthesized independently and the MNPs subsequently integrated into the PAA hydrogel network by particle diffusion and physical entrapment.No adverse effects on swelling and ammonium sorption following immersion in either synthetic or real sewage were observed after MNPs were incorporated into the hydrogels.Importantly,PAA-MNP hydrogels demonstrated high ammonium sorption efficiencies(80-93%)in real sewage and achieved rapid ammonium recovery of 73±1.1% within 15 min of mild acid washing(pH 4)15 min at a maximum recovery.展开更多
By 2050,the societal needs and innovation drivers of the 21st century will be in full swing:mitigating climate change,minimizing anthropogenic effects on natural ecosystems,navigating scarcity of natural resources,and...By 2050,the societal needs and innovation drivers of the 21st century will be in full swing:mitigating climate change,minimizing anthropogenic effects on natural ecosystems,navigating scarcity of natural resources,and ensuring equitable access to quality of life will have matured from future needs to exigent realities.Water is one such natural resource,and will need to be treated and transported to maximize resource efficiency.In particular,wastewater will be mined for the valuable product precursors it contains,which will require highly selective separation processes capable of capturing specific target compounds from complex solutions.As a case study,we focus on the nitrogen cycle because it plays a central role in both natural and engineered systems.Nitrogen occurs as several species,including ammonia,a fertilizer and precursor to many nitrogen products,and nitrate,a fertilizer and component of explosives.We describe two applications of selective separations:selective materials and electrochemical processes.Ultimately,this perspective outlines the next thirty years of modular,selective,resource-efficient separations that will play a major role in enabling element-specific circular economies and redefining wastewater as a resource.展开更多
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funded by the Deanship of Scientific Research at the University of Jordan.
文摘The composition of paper cups creates a challenge for the recycling industry,as the paperboard–plastic film composite is hard to separate.Therefore,paper cups are sent to landfills or waste incinerators.This study explores the combined use of red worms(Eisenia fetida)and Greater wax moth(Galleria mellonella)in the biodegradation of paper cups.The study investigates the conditions and combinations that promote using Eisenia fetida and Galleria mellonella for degrading paper cups.The study considered the influence of environmental temperature,the presence of food waste,varying the number of Eisenia fetida worms,and the presence of a Galleria mellonella growth-slowing agent on the degradation process.To achieve the study objectives,the study followed a quantitative approach.The study monitored the degradation of paper cup cuts that were placed in jars containing different combinations of Eisenia fetida worms,Galleria mellonella larvae,food waste,bedding material,and Galleria mellonella growth-slowing agents.The study found that the best operating temperature is 30oC.The study found that using food waste improves the performance of Eisenia fetida worms and Galleria mellonella larvae significantly.The study found that adding a Galleria mellonella growth-slowing agent slightly enhances the degradation of the paper cup.Finally,a numerical model was obtained to simulate the paper cup degradation efficiency.
基金supported by the Fundamental Research Funds for the Central Universities(No.20822041B4013)Key Laboratory of Development and Application of Rural Renewable Energy,Ministry of Agriculture and Rural Affairs,China(No.18H0491)。
文摘A vacuum membrane distillation(VMD)process with permeate fractional condensation on membrane downstream has been developed for simultaneous recovery of phosphorus and nitrogen from liquid digestate.The polytetrafluoroethylene(PTFE)membrane flux could reach 6000 g·m-2·h-1 with the rejection efficiency of total phosphorus(TP)over 0.99,under the condition of flowrate being 120 L·h-1 and temperature being 40°C.Membrane fouling occurred with a film of organics and microorganism deposited on the surface of the membrane.Membrane flux could be reversed after the membrane was rinsed by water.Higher feed temperature and flowrate could improve the membrane flux,while hardly affect the rejection efficiency of total phosphorus.The concentration of TP could reach 1600 mg·L-1 after membrane distillation,which is about 5 times of that in initial liquid digestate.On the downstream of the membrane,some of the permeate vapor was condensed under the vacuum condition and most of water was collected here.The remaining vapor enriched with total nitrogen(TN)was compressed and pumped to the atmospheric condition to condense.The TN concentration in atmospheric condensate was as high as 7000 mg·L-1 with the process separation factor for ammonia being enhanced to 114.
基金supported by the National Natural Science Foundation of China“Behavioral Experiment and Policy Research of Pig Farmers when Diseased Dead Pigs Entering the Market”[Grant number 71540008]the Key Projects of the National Natural Science Foundation of China“Experimental Assessment of Agricultural Producer Safety Production Policy and Its Combined Design:Taking the Treatment of Diseased Dead Pigs as an Example”[Grant number.71673115]+3 种基金the Fundamental Research Funds for the Central Universities“Food Safety Risk Management Logic and Realistic Path Based on Big Data”[Grant number JUSRP1808ZD]the National College Student Innovation Training Program[Grant number 201810295025]the National Key R&D Program Funding Project[Grant number 2018YFC1603303]the National Key R&D Program Funding Project[Grant number 2018YFC1604000].
文摘Ecological compensation is widely considered a policy that encourages farmers to recycle livestock and poultry waste for economic and ecological benefits.Therefore,based on field data from 30 counties(districts)in six cities of Shandong Province,China,this study systematically analyzes farmers'willingness to accept compensation for livestock and poultry waste resource utilization as well as its determinants.It does so using the UTAUT theoretical analysis framework,as well as the contingent valuation method and Heckman two-stage selection model.The results show that,first,72.4%of the farmers in the sample are willing to accept a certain amount of compensation—the expected value of which is RMB 98.02 per month per household—as an incentive to utilize livestock waste.Second,the key determinants of farmers'willingness to accept compensation are marital status,family annual income,concurrent business,farming scale,economic performance expectation,social performance expectation,knowledge reserve,public relations,and technical convenience.Finally,the factors that affect farmers’willingness in terms of the compensation amount are gender,age,family annual income,social performance expectation,subjective norms,and public relations.Therefore,to promote the recycling of livestock and poultry waste,this study proposes policies that promote education and technology popularization in relation to livestock and poultry waste resource utilization,provide subsidies for waste recycling,and strengthen government control and social supervision over the non-standard disposal of such waste.
基金supported by the National Natural Science Foundation of China“Behavioral Experiment and Policy Research of Pig Farmers when Diseased Dead Pigs Entering the Market”[Gant number 71540008]the Key Projects of National Natural Science Foundation of China“Experimental Assessment of Agricultural Producer Safety Production Policy and Its Combined Design:Taking the Treatment of Diseased Dead Pigs as an Example”[Grant number 71673115]+3 种基金the Fundamental Research Funds for the Central Universities“Food Safety Risk Management Logic and Realistic Path Based on Big Data”[Grant number.JUSRP1808ZD]the National College Student Innovation Training Program[grant number.201810295025]the National Key R&D Program Funding Project[Grant number.2018YFC1603303]the National Key R&D Program Funding Project[Grant number.2018YFC1604000].
文摘Based on field research data on farmers in 30 counties(districts)of six cities in Shandong Province,this study systematically examines the methods of disposal of livestock and poultry waste and the factors that influence them,that is,the determinants of farmers’waste disposal behaviors,using the UTAUT theoretical framework and a disordered multi-class logit model.The results show that,first,economic performance expectancy,subjective norms,farming population,and poultry and livestock breeding numbers have significant effects on the four waste recycling methods considered:direct return,compost fermentation,biogas fermentation,and fresh-packed sale.Second,annual family income has a positive effect on the direct return method.Third,compost fermentation is positively affected by farmers'knowledge,distance from sources of water,and farming scale,and negatively affected by gender and marital status.Fourth,biogas fermentation is negatively affected by the age of farmers and positively affected by the farming income ratio and environmental convenience.Finally,the most important factors affecting the four methods are subjective norms,farming scale,economic performance expectancy,and farming population.Therefore,this study proposes that policies to promote resource utilization of livestock and poultry waste must prioritize raising awareness among the farmers of the advantages of resource disposal of waste;provide reasonable subsidies for waste recycling and enhance policy applicability,pertinence,and motivation;strengthen the promotion of waste recycling technology and improve the practicality of lectures or training content;and improve relevant laws and regulations and enhance authority and usability.
文摘In order to recover the strip pillar coal resources, reduce the amount of gangue mountain and realize remediation of the goaf environment in the old mining area, the raw gangue filling mining technology was proposed. According to the previous practical experience, the feasibility of the implementation of raw gangue filling mining technology in the coal-pressed area was analyzed. Through the filling gangue compaction test, the deformation under different loading stages was obtained. Further, a reasonable prediction of the deformation beyond the experimental limited loading load was made based on the experimental results. Through the deformation source analysis of the whole process of gangue filling, the key factors for controlling deformation before, during, and after filling were determined. Additionally, the proportion of deformation during different stages was quantified. Considering the protection of surface buildings, mining fullness of the working face and mining technology, the production parameters of 1209 and 1210 filling working faces were preliminarily determined. Through numerical simulation, the rationality of mining scheme was verified. Based on the practice of 1209 working face and the key factors to control the deformation of gangue filling, the mining system and process in 1210 working face were optimized. According to the measured surface rock movement, raw gangue filling mining technology can meet the requirements of surface building protection level. Especially, this paper provides a method to quantitatively calculate the equivalent mining height (EMH) of raw gangue filling and its mining deformation, which has reference significance for old mining areas.
基金supported by the Tomsk Polytechnic University development program.
文摘Carbonate reservoirs generally achieved relatively low primary resource recovery rates.It is therefore often necessary to clean those reservoirs up and/or stimulate them post drilling and later in their production life.A common and basic carbonate reservoir cleanup technique to remove contaminating material from the wellbore is acidizing.The efficiency of acid treatments is determined by many factors,including:the type and quantity of the acid used;the number of repeated treatments performed,heterogeneity of the reservoir,water cut of the reservoir fluids,and presence of idle zones and interlayers.Post-treatment production performance of such reservoirs frequently does not meet design expectations.There is therefore much scope to improve acidizing technologies and treatment designs to make them more reliable and effective.This review considers acid treatment technologies applied to carbonate reservoirs at the laboratory scale and in field-scale applications.The range of acid treatment techniques commonly applied are compared.Differences between specific acid treatments,such as foamed acids,acid emulsions,gelled and thickened acid systems,targeted acid treatments,and acid hydraulic fracturing are described in terms of the positive and negative influences they have on carbonate oil production rates and recovery.Opportunities to improve acid treatment techniques are identified,particularly those involving the deployment of nanoparticles(NPs).Due consideration is also given to the potential environmental impacts associated with carbonate reservoir acid treatment.Recommendations are made regarding the future research required to overcome the remaining challenges pertaining to acid treatment applications.
文摘Given the conditions of residual coal from the boundary of a flat dipping open-pit mine,which uses strip areas mining and inner dumping with slope-covering,we propose an open-pit and underground integrated mining technology for residual coal of end slopes.In the proposal a conveyance road and ventilation conveyance near the slope are built,corresponding to the pit mining area and the surface coal mine dump,as well as an interval haulage tunnel and air-inlet tunnel.The outcome shows that such mining method may reduce the effect to slope stability from underground mining,it does not affect the dumping advance and has a high recovery rate of residual coal resources.The working face is timbered by single hydraulic props,transported by a scraper conveyor and supported by coal walls.This method of mining is one of layered top coal caving,with high resource recovery,low production cost where positive economic benefit can be realized.
文摘Absence of wastewater and solid waste facilities impacts the quality of life of many people in developing countries. Implementation of these facilities will benefit public health, water quality, livelihoods and property value. Additional benefits may result from the potential recovery of valuable resources from wastewater and solid waste, such as compost, energy, phosphorus, plastics and paper. Improving water quality through implementation of wastewater and solid waste interventions requires, among others, an analysis of i) sources of pollution, ii) mitigating measures and resource recovery potentials and their effect on water quality and health, and iii) benefits and costs of interventions. We present an integrated approach to evaluate costs and benefits of domestic and industrial wastewater and solid waste interventions. To support a policy maker in formulating a cost and environmentally effective approach, we quantified the impact of these interventions on 1) water quality improvement, 2) resource recovery potential, and 3) monetized benefits versus costs. The integration of technical, hydrological, agronomical and socio-economic elements to derive these three tangible outputs in a joint approach is a novelty. The approach is demonstrated using the heavily polluted Indonesian Upper Citarum River in the Bandung region. Domestic interventions, applying simple (anaerobic filter) technologies, were economically most attractive with a benefit cost ratio (BCR) of 3.2, but could not reach target water quality standards. To approach the target water quality, both advanced domestic (nutrient removal systems) and industrial wastewater treatment interventions were required, leading to a BCR of 2. We showed that benefits from selling recovered resources represent here an additional driver for improving water quality and outweigh the additional costs for resource recovery facilities. While included benefits captured some of the major items, these may have been undervalued. Based on these findings, water quality interventions justify their costs and are socially and economically beneficial.
基金supported by the Key Research and Development Project of Shandong Province,China(2020CXGC011202-004)the State Key Laboratory of Urban Water Resources and Environment(Harbin Institute of Technology),China(No.2022TS26)the Shenzhen Science and Technology Innovation Program,China(KQTD20190929172630447).
文摘Carbon cycle regulation and greenhouse gas(GHG)emission abatement within wastewater treatment plants(WWTPs)can theoretically improve sustainability.Currently,however,large amounts of external carbon sources used for deep nitrogen removal and waste sludge disposal aggravate the carbon footprint of most WWTPs.In this pilot-scale study,considerable carbon was preliminarily recovered from primary sludge(PS)through short-term(five days)acidogenic fermentation and subsequently utilized on-site for denitrification in a wool processing industrialWWTP.The recovered sludge-derived carbon sources were excellent electron donors that could be used as additional carbon supplements for commercial glucose to enhance denitrification.Additionally,improvements in carbon and nitrogen flow further contributed to GHG emission abatement.Overall,a 9.1%reduction in sludge volatile solids was achieved from carbon recovery,which offset 57.4%of external carbon sources,and the indirect GHG emissions of the target industrial WWTP were reduced by 8.05%.This study demonstrates that optimizing the allocation of carbon mass flow within a WWTP has numerous benefits.
基金This study was supported by Taishan Scholars Project Special Funds(tsqn201812083)the Natural Science Foundation of Shandong Province(ZR2019YQ20 and 2019JMRH0410)the National Natural Science Foundation of China(51972147,52022037 and 52002145).
文摘The resource recovery of heavy metals from effluent has significant environmental implications and potential commercial value.Chromium phosphide nanoparticles embedded in a nitrogen-/phosphorus-doped porous carbon matrix(CrP/NPC)are synthesized via a consecutive Cr^(6+)leachate treatment and resource recovery process.Electrochemical testing shows that CrP/NPC shows excellent nitrogen reduction reaction(NRR)performance,which yields the highest NH_(3) production rate of 22.56μg h^(−1) mg^(−1)_(cat).and Faradaic efficiency(16.37%)at−0.5 V versus the reversible hydrogen electrode in a 0.05M Na_(2)SO_(4) aqueous solution,as well as robust catalytic stability.The isotopic experiments using ^(15)N^(2) as a nitrogen source confirm that the detected NH_(3) is derived from the NRR process.Finally,density functional theory(DFT)calculations show that the electron deficiency environment of the Cr site can significantly reduce the barrier of the NRR process and promote the formation of intermediate species.
基金Project supported by the Natural National Science Foundation of China(21707167)。
文摘Red mud is a byproduct of alumina refining of bauxite ores,and is a significant source for extracting scandium.However,a large amount of iron in red mud makes it difficult to recover scandium because Fe(III) and Sc(Ⅲ) have similar physicochemical properties.In this study,a new method was developed for selective separation of iron and scandium in acid leachate of red mud using D201 resin.Theoretical calculations indicate that the ferric species mainly exists as FeCl3 or FeCl4-at chloride concentration above 6.65 mol/L,while scandium still exists as SCl2+,making it possible to selectively separate iron fro m scandium through anion resin adso rption.The factors affecting the adso rption of iron and scandium such as chloride conce ntratio n,resin dosage,adso rption time,and temperature were evaluated in batch experiments,The Langmuir model was successfully applied to both iron and scandium adsorption,and the maximum adsorption capacities of iron and scandium are 147.06 and 0.95 mg/g,respectively,indicating a significant difference between iron and scandium.Raman analysis further demonstrates that the iron is adsorbed onto D201 resin as FeCl4 anion.
文摘Wastewaters from various process industries,namely food and agricultural,sugar mill,brewery,milk,vegetable and fruit,and meat and fsheries processing industries and their wastewater efuents contain nutrients,organic matter,inorganic,heavy metals,suspended solids,and pathogens.The discharges of non-treated wastewater enter the nearby aquatic ecosystem(e.g.,lakes,rivers)and are a signifcant concern due to the presence of diferent nutrients,competing ions and C containing pollutants.It causes excessive growth of algae,loss of habitat/species,and other negative impacts on human health/environment.In the present review,diferent treatment approaches have been discussed in utilizing these nutrients to synthesize value-added products such as biopolymer,biofuel,pigment,organic acid,or enzymes.These biopolymers can be used to prepare various food products/packaging materials.Dextran,chitosan,carrageenan,alginate,and pectin are good examples of non-food biopolymers.Besides these products,poly-β-hydroxybutyrate(PHB)synthesis from wastewater nutrients is reported as a new source of bio-nanocomposite materials/biopolymer-based coatings.In this review,the diferent treatment approaches are discussed,which are being used worldwide for the removal/recovery of nutrients,toxic pollutants,and the potential resource recovery of value-added products from wastewater.
基金supported by the National Natural Science Foundation of China(Grant No.51877184).
文摘The increasing amount of food waste from various industrial,agricultural,and household sources is an environmental burden if managed inappropriately.Numerous waste management approaches have been developed for the disposal of food waste,but still suffer from either high cost,production of toxic by-products,or secondary environmental pollutions.Herein,we report a new and sustainable plasma electrolysis biorefinery route for the rapid and efficient liquefaction of food waste.During the plasma electrolysis process,only the solvent is added to liquefy the waste,and anions in the waste can contribute to catalyzing the biowaste conversion.While liquefying the waste,the highly reactive species produced in the plasma electrolysis process can efficiently reduce the content of O,N,and Cl in the liquefied products and oxidize most of the metals into solid residues.Especially,the removal rate of Na and K elements was greater than 81%,which is significantly higher than using the traditional oil bath liquefaction,resulting in a relatively high-quality biocrude oil with a high heating value of 25.86 MJ·kg^(-1).Overall,this proposed strategy may provide a new sustainable and eco-friendly avenue for the power-to-chemicals valorization of food waste under benign conditions.
基金financial support from the Natural Sciences and Engineering Research Council of Canada
文摘This study reports the feasibility of using municipal wastewater biosolids as an alternative carbon source for biological phosphorus removal.The biosolids were treated by a lowtemperature,thermal alkaline hydrolysis process patented by Lystek International Inc.(Cambridge,ON,Canada)to produce short-chain volatile fatty acids and other readily biodegradable organics.Two sequencing batch reactors(SBRs)were operated with synthetic volatile fatty acids(Syn VFA)and readily biodegradable organics produced from the alkaline hydrolysis of municipal wastewater biosolids(Lystek)as the carbon source,respectively.Municipal wastewaters with different strengths and COD:N:P ratios were tested in the study.The reactors’performances were compared with respect to nitrogen and phosphorus removal.It was observed that phosphorus removal efficiencies were between 98%–99%and 90%–97%and nitrogen removal efficiencies were 78%–81%,and 67%for the Syn VFA and Lystek,respectively.However,the kinetics for phosphorus release and uptake during the anaerobic and aerobic stages with Lystek were observed to be significantly lower than Syn VFA due to the presence of higher order VFAs(C4 and above)and other fermentable organics in the Lystek.
基金supported by The University of Queensland scholarship awardUQ New Staff Startup-up Grant scheme.
文摘Ammonium sorption and recovery processes typically take place in conventional packed columns,with a configuration that enables maximum sorption by the sorbents.However,batch or semi-continuous operations in packed columns have associated issues such as scaling and frequent backwashing requirements,which are economically prohibitive.As an alternative,ammonium sorption could occur in well-mixed continuously stirred tanks,which would allow for the ammonium sorption process to be retrofitted in existing wastewater treatment plants,provided that efficient sorbent separation can be achieved.This study demonstrates,for the first time,the preparation of magnetic poly(acrylic acid)-based(PAA)ammonium sorbents through the incorporation of magnetic(Fe_(3)O_(4))nanoparticles(MNP)produced via scalable and cost-effective electrochemical synthesis.The MNP and PAA hydrogels were synthesized independently and the MNPs subsequently integrated into the PAA hydrogel network by particle diffusion and physical entrapment.No adverse effects on swelling and ammonium sorption following immersion in either synthetic or real sewage were observed after MNPs were incorporated into the hydrogels.Importantly,PAA-MNP hydrogels demonstrated high ammonium sorption efficiencies(80-93%)in real sewage and achieved rapid ammonium recovery of 73±1.1% within 15 min of mild acid washing(pH 4)15 min at a maximum recovery.
文摘By 2050,the societal needs and innovation drivers of the 21st century will be in full swing:mitigating climate change,minimizing anthropogenic effects on natural ecosystems,navigating scarcity of natural resources,and ensuring equitable access to quality of life will have matured from future needs to exigent realities.Water is one such natural resource,and will need to be treated and transported to maximize resource efficiency.In particular,wastewater will be mined for the valuable product precursors it contains,which will require highly selective separation processes capable of capturing specific target compounds from complex solutions.As a case study,we focus on the nitrogen cycle because it plays a central role in both natural and engineered systems.Nitrogen occurs as several species,including ammonia,a fertilizer and precursor to many nitrogen products,and nitrate,a fertilizer and component of explosives.We describe two applications of selective separations:selective materials and electrochemical processes.Ultimately,this perspective outlines the next thirty years of modular,selective,resource-efficient separations that will play a major role in enabling element-specific circular economies and redefining wastewater as a resource.
