Composting of Disposal Organic Wastes: Resource Recovery for Agricultural Sustainability

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.

Application of UiO-66 and its composites for remediation and resource recovery of typical environmental contaminants:a review

UiO-66 series metal-organic framework materials(MOFs)are typical porous materials assembled by Zr^(4+) with a large mass-to-nucleus ratio and terephthalic acid ligands,which form tetrahedral and octahedral cages arranged in a periodic triangular window pattern.Due to the strong interaction between Zr and O,UiO-66 series MOFs exhibit high thermal stability,structural stability,and chemical stability.This article mainly reviews the applications of UiO-66 and its composites in adsorption,photocatalysis,and resource utilization,while exploring the harm of pollutants to human health and the environment.In the first part,the differences in adsorption and removal mechanisms of liquid organic pollutants,heavy metals,and volatile organic compounds(VOCs)are investigated.The results show that organic pollutants are mainly removed by physical adsorption,electrostatic interactions,hydrogen bonding,andπ-πinteractions,while heavy metals are mainly removed by chemical adsorption,electrostatic interactions,reduction,and chelation.VOCs are mainly removed by the pore volume and pore size structure of the material.Heterojunction catalysis can achieve non-toxic treatment of pollutants,and this study mainly focuses on UiO-based composite materials constructed by strategies such as semiconductor composites,ion doping,and metal/dye encapsulation.In the second part,the synergistic effect between the components of UiO-based composite materials promotes the oriented and rapid separation and transfer of earriers at the material interface,thereby promoting the generation of active species such as h^(+),·O_(2)^(-) and·OH,and achieving rapid degradation of pollutants and detoxification of heavy metals.In the third part,heterojunctions can realize the resource utilization of pollutants in water and air,producing energy-type substances such as hydrogen and methanol while solving environmental problems.In addition,this article also summarizes the harm of common typical pollutants to the environment and human health.Finally,the development prospects and unresolved problems of UiO-66-based materials in water remediation,gas purification,and environmental resource utilization are reviewed.

Nanoscale Zero-Valent Iron(nZVI)for Heavy Metal Wastewater Treatment:A Perspective

Industries such as non-ferrous metal smelting discharge billions of gallons of highly toxic heavy metal wastewater(HMW)worldwide annually,posing a severe challenge to conventional wastewater treatment plants and harming the environment.HMW is traditionally treated via chemical precipitation using lime,caustic,or sulfide,but the effluents do not meet the increasingly stringent discharge standards.This issue has spurred an increase in research and the development of innovative treatment technologies,among which those using nanoparticles receive particular interest.Among such initiatives,treatment using nanoscale zero-valent iron(nZVI)is one of the best developed.While nZVI is already well known for its site-remediation use,this perspective highlights its application in HMW treatment with metal recovery.We demonstrate several advantages of nZVI in this wastewater application,including its multifunctionality in sequestrating a wide array of metal(loid)s(>30 species);its capability to capture and enrich metal(loid)s at low concentrations(with a removal capacity reaching 500 mg·g^(-1)nZVI);and its operational convenience due to its unique hydrodynamics.All these advantages are attributable to nZVI’s diminutive nanoparticle size and/or its unique iron chemistry.We also present the first engineering practice of this application,which has treated millions of cubic meters of HMW and recovered tons of valuable metals(e.g.,Cu and Au).It is concluded that nZVI is a potent reagent for treating HMW and that nZVI technology provides an eco-solution to this toxic waste.

Enhancing the Decomposition of Paper Cups Using Galleria Mellonella and Eisenia Fetida

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.

Detoxification of chromium-containing slag by Achromobacter sp.CH-1 and selective recovery of chromium

Based on the principle of bacterial leaching and bacterial metallurgy,a novel technology for the detoxification of chromium-containing slag by Achromobacter sp.CH-1 and chromium recovery was proposed.Strain CH-1 cell morphology before and after Cr(Ⅵ) reduction was observed with a scanning electron microscope(SEM),and the reduction product is found to adhere to terminals of CH-1 cells.Energy-dispersive X-ray(EDX) and electron paramagnetic resonance(EPR) analyses reveal that the main component of the reduction product is Cr(Ⅲ).Furthermore,small and large-scale demonstration projects reveal that Achromobacter sp.can be used to detoxify chromium-containing slag and to selectively recover chromium by using this novel technique.Chromium recovery rate increases with decreasing particle sizes of chromium-containing slag and slagheap height.Chromium recovery rates in 10 t/batch and 20 t/batch of on-site demonstration projects for chromium-containing slag detoxification are more than 90%.

Vacuum-Aided Recovery Technology of Spent Ni-Cd Batteries

Recovery of Ni-Cd batteries was studied by a self-designed vacuum-aided recovering system under laboratory conditions. The fundamental research on a process of disassembling and recovering selected materials from Ni-Cd batterieswas conducted. The impacts of temperature, pressure and time were studied respectively. The mechanism of vacuum thermal recovering was also discussed. The results show that: Ni-Cd batteries can be recovered effectively byvacuum-aided recovering system at 573~1173 K. At constant pressure, the increase of temperature can improve theseparating efficiency of cadmium. When the temperature is 1173 K, the cadmium can evaporate completely fromthe residue during 3 h at 10 Pa. The reduction of pressure in the certain range is effective to separate cadmium byvacuum distillation. Distillation time is a very important factor affecting separation of cadmium.

Simultaneous recovery of phosphorus and nitrogen from liquid digestate by vacuum membrane distillation with permeate fractional condensation

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.

Farmers’willingness to accept compensation for livestock and poultry waste resource utilization and its determinants

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.

Segregation Treatment and Resource Recycling of Enteric Coating and Heparin Sodium Manufacturing Wastewater

Firstly, the water-quality characteristics of intestinal lavage wastewater and enzymolysis wastewater from the typical heparin sodium pro- ductive process were analyzed, and then the segregation treatment was applied in the treatment of enteric coating and heparin sodium manufacturing wastewater. Finally, the treatment of the two kinds of wastewater by different methods were discussed. The results showed that, COD of enzymolysis wastewater treated by centrifugation-coagulation-Fenton reagent oxidation-adsorption process was lower than 100 mg/L, while intestinal lavage wastewater treated by coagulation-ASBR-SBR process could meet the first standard of Comprehensive Discharge Standard of Sewage （GB8978-1996） after one month of continuous operation.

An analysis of farmers'resource disposal methods for livestock and poultry waste and their determinants

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.

Raw Gangue Filling Mining under Construction —A Case Study in China

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.

A critical review of self-diverting acid treatments applied to carbonate oil and gas reservoirs

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.

Application of open-pit and underground mining technology for residual coal of end slopes

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.

Chromium phosphide nanoparticles embedded in porous nitrogen-/phosphorus-doped carbon as efficient electrocatalysts for a nitrogen reduction reaction

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.

An Integrated Approach to Evaluate Benefits and Costs of Wastewater and Solid Waste Management to Improve the Living Environment: The Citarum River in West Java, Indonesia

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.

Carbon source recovery from waste sludge reduces greenhouse gas emissions in a pilot-scale industrial wastewater treatment plant

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.

废纸资源化的新技术

废纸资源化是解决环境污染、原料短缺和能源紧张问题的有效途径之一。目前,世界各国关于废纸资源化技术的研究已经取得很大进展。因为原料易得,工艺过程简单,既节约资源,又保护环境,因此,可以取行良好的经济效益和社会效益。而我国目前废纸资源化技术单一,主要用于造纸业。为了更好地节约森林资源,保护生态环境,有必要探索废纸资源化的新技术。

Effect of urban symbiosis development in China on GHG emissions reduction

This paper analyzes current urban symbiosis development and application in China, and then conducts a statistical analysis of the emissions reduction of CO2 and CH4 in relation to recovery of iron and steel scraps, waste paper, and waste plastics from 2011 to 2014 using the greenhouse gas（GHG） emission inventory calculation method provided by the IPCC. Results indicate that the cumulative recovery of renewable resources during China＇s main urban symbiosis development in 2011-2014 was 803.275 Mt, and the amount of iron and steel scraps, waste paper, and waste plastic recovery was the largest, respectively accounting for 62.2%, 18.0%, and 8.2% of total recovery in 2014. In addition, the cumulative emissions reduction of GHGs in relation to recovery of iron and steel scraps, waste paper, and waste plastics in 2011-2014 was27.962 Mt CO2-eq, 954.695 Mt CO2-eq, and 22.502 Mt CO2-eq, respectively, thereby totaling 1005.159 Mt CO2-eq. Results show a remarkable GHG emissions reduction during 2011-2014.

Dechlorination of zinc dross by microwave roasting

Traditional treatments of zinc dross have many disadvantages,such as complicated recovering process and serious environmental pollution.In this work,a new process of chlorine removal from zinc dross by microwave was proposed for solving problem of recycling the zinc dross.With better ability of absorbing the microwave than zinc oxide,the main material in zinc dross,chlorides,can be heated and evaporated rapidly during microwave roasting.Various parameters including roasting temperature,duration time and stirring speed were optimized.The microstructure of roasted materials was characterized by X-ray diffraction(XRD) and scanning electron microscope(SEM).The content of the chloride was analyzed by the method of chlorine ion selective electrode.The experiments indicate that the best duration time is 60 min with a stirring speed of 15 r/min during the microwave roasting process.The dechlorination rate reaches peak value of 88% at 700 ℃.The chlorine is removed as HCl gas when water vapor is used as activating agent,which means that it can be recovered into hydrochloride acid.

Renewable biosynthesis of isoprene from wastewater through a synthetic biology approach:the role of individual organic compounds

The biosynthesis of isoprene offers a more sustainable alternative to fossil fuel-based approaches,yet its success has been largely limited to pure organic compounds and the cost remains a challenge.This study proposes a waste-to-wealth strategy for isoprene biosynthesis utilizing genetically engineered E.coli bacteria to convert organic waste from real food wastewater.The impact of organic compounds present in wastewater on E.coli growth and isoprene production was systematically investigated.The results demonstrated that with filtration pretreatment of wastewater,isoprene yield,and production achieved 115 mg/g COD and 7.1 mg/(L·h),respectively.Moreover,even without pretreatment,isoprene yield only decreased by~24%,indicating promising scalability.Glucose,maltose,glycerol,and lactate are effective substrates for isoprene biosynthesis,whereas starch,protein,and acetate do not support E.coli growth.The optimum C/N ratio for isoprene production was found to be 8:1.Furthermore,augmenting essential nutrients in wastewater elevated the isoprene yield increased to 159 mg/g COD.The wastewater biosynthesis significantly reduced the cost(44%–53%decrease,p-value<0.01)and CO_(2)emission(46%–55%decrease,p-value<0.01)compared with both sugar fermentation and fossil fuel–based refining.This study introduced a more sustainable and economically viable approach to isoprene synthesis,offering an avenue for resource recovery from wastewater.