This applied research seeks to explore feasible plant design for manufacturing insulation materials for construction projects using waste sheep fleece to address environmental issues related to wasted sheep wool and e...This applied research seeks to explore feasible plant design for manufacturing insulation materials for construction projects using waste sheep fleece to address environmental issues related to wasted sheep wool and enhance the gross national product. The process starts by collecting low-cost sheep fleece from farms and processed via a production line, including scouring, plucking, carding, thermal bonding, and packing. The design process involves determining an optimal location, infrastructure, staffing, machinery, environmental impact, and utilities. A final economic analysis is undertaken to estimate the product’s cost, selling price, and break-even point based on the anticipated capital and operational costs. The plant is intended to process 6778 tons of sheep wool annually. The study suggests that Mafraq Industrial City is a perfect location for the plant, and purchasing land and structures is the optimal option. The projected capital cost is 1,416,679 USD, while the anticipated operational costs amount to 3,206,275 USD. Insulation material production is estimated to be 114,756 m3 annually. The material may be manufactured into 1 m wide, 0.05 m thick sheets for 2.02 USD per square meter. Thus, for a 10-year plant, a 2.47 USD/m2 selling price breaks even in one year.展开更多
The direct emission of waste refinery gas after combustion will cause a severe greenhouse effect.Recovering high-value-added ethylene from wasted refinery gas has fundamental economic and environmental significance. D...The direct emission of waste refinery gas after combustion will cause a severe greenhouse effect.Recovering high-value-added ethylene from wasted refinery gas has fundamental economic and environmental significance. Due to the complexity of the composition of refinery waste gas, designing and optimizing the whole recovery process is still a challenging task. Herein, a novel process(SCOAS) was proposed to obtain polymer-grade ethylene from wasted refinery gas through a direct separation process,and heat pump-assisted thermal integration optimization(HPSCOAS) was carried out. The unique feature of the novel approach is that a new stripper and ethylene reabsorber follow the dry gas absorber to ensure ethylene recovery and methane content. An industrial model, shallow cooling oil absorption(SCOA), and concentration combined cold separation system of ethylene unit using wasted refinery gas was established to analyze the technology and environment. Based on the detailed process modeling and simulation results, the quantitative sustainability assessment of economy and environment based on product life cycle process is carried out. The results show that compared with the traditional process when the same product is obtained, the total annual cost of the HPSCOAS process is the lowest, which is 15.4% lower than that of the SCOA process and 6.1% lower than that of the SCOAS process. In addition,compared with the SCOA process and the HPSCOAS process, the SCOAS process has more environmental advantages. The non-renewable energy consumed by SCOAS is reduced by about 24.8% and 6.1%, respectively. The CO_(2) equivalent is reduced by about 38.6% and 23.7%.展开更多
An old automotive industrial site located at Mexico City with many years of operation and contaminated with heavy oil hydrocarbons, particularly spent oils, was assessed for restoration using the surfactant enhanced s...An old automotive industrial site located at Mexico City with many years of operation and contaminated with heavy oil hydrocarbons, particularly spent oils, was assessed for restoration using the surfactant enhanced soil washing (SESW) process. The main goal of this study was to characterize the contaminated soil in terms of TPHs, BTEX, PAHs, and metals contents as well as microbiologically (total heterotrophs and specific degrading microorganisms). We also aimed to determine the surfactant type and concentration to be used in the SESW process for the automotive waste oil contaminated soil. At the end, sixteen kg of contaminated soil were washed and the produced wastewater (approximately 40 L) was characterized in terms of COD, BOD;solids, and other physico-chemical parameters. The soil contained about 14,000 mg of TPH/kg soil (heavy fraction), 0.13 mg/kg of benzo (k) fluoranthene and 0.07 mg/kg of benzo (a) pyrene as well as traces of some metals. Metals concentrations were always under the maximum concentration levels suggested by Mexican regulations. 15 different surfactants were used to identify the one with the capability to achieve the highest TPH removal. Surfactants included 5 anionics, 2 zwitterionic, 5 nonionics and 3 natural gums. Sulfopon 30 at a concentration of 0.5% offered the best surfactant performance. The TPH removals employing the different surfactants were in the range from 38% to 68%, in comparison to the soil washing with water (10% of TPH removal). Once the surfactant was selected, 70 kg of soil were washed and the resulting water contained approximately 1300 mg/L of COD, 385 mg/L of BOD (BOD/COD = 0.29), 122 mg/L of MBAS, and 212 mg/L of oil and greases, among other contaminants.展开更多
In the global environment of pursuing resource regeneration and green environmental protection, more and more wasted clothing need to be solved. In order to make full use of the wasted clothing and save land and soil ...In the global environment of pursuing resource regeneration and green environmental protection, more and more wasted clothing need to be solved. In order to make full use of the wasted clothing and save land and soil resources, an idea of wasted clothing's recycling and remanufacturing is put forward. In the new idea a pricing game model is established basing on Stacklberg differential game theory between traditional and remanufactured clothing. In this model, the differences in consumers' willingness to pay and the government's subsidies are considered. Government's optimal subsidy are obtained which ensure not only the interests of manufacturers but also environmental reputation and maximum social benefits. The study is helpful to push the wasted clothing's recycling and remanufacturing plan. It makes some index more precise quantification as government's subsidy, manufacturers and the social benefits. Government and manufactures can make the detailed cooperation plan reference to it.展开更多
Electronic scrap, especially wasted printed circuit boards (PCBs), is regarded as an environmental challenge. At present, the physical separation is thought to be the environmental friendly and economical method of tr...Electronic scrap, especially wasted printed circuit boards (PCBs), is regarded as an environmental challenge. At present, the physical separation is thought to be the environmental friendly and economical method of treating and reutilizing electronic waste. An effective liberation of metals from non metallic components is a crucial step towards mechanical separation and recycling of wasted PCBs. In this paper, the selective shredding theory and mechanics characteristics of wasted PCBs were analyzed, and the shredded experiments of wasted PCBs by hammer mill were investigated. The result shows that the selective shredding exists in the wasted PCBs shredded process by hammer mill. The shredding velocity of non metallic components is far greater than that of metals in the wasted PCBs shredding, which makes the metals concentrate in the coarser fraction. And the impact force of hammer mill is superior to metal liberation from non metallic components, a satisfied metal liberation degree can be achieved in the wasted PCBs shredding by hammer mill.展开更多
The Kingdom of Saudi Arabia produces over one million metric tons annually, which returns a 20% of wasted dates annually. Lactic acid and its derivatives are widely used in food, pharmaceutical and textile industries....The Kingdom of Saudi Arabia produces over one million metric tons annually, which returns a 20% of wasted dates annually. Lactic acid and its derivatives are widely used in food, pharmaceutical and textile industries. There has been an increase in lactic acid production because it is used as a raw material to produce polylactic acid, a polymer that is used as a special medical and environmental friendly biodegradable plastic. This study aimed to use wasted dates to produce lactic acid by single culture Lactobacillus casei (ATCC 393), Lactobacillus acidophilus (CICC 6088) and the mixed culture using batch fermentation. The investigation results showed that the maximum concentration of lactic acid for ATCC 393, CICC 6088 and the mixed culture are 87, 84 and 84 g/l respectively. For single CICC 6088 and the mixed culture, the total percentage of glucose and fructose utilized was found to be 100%;76%, respectively, whereas in the case of the single culture ATCC 393, the total percentage of glucose and fructose were 100% and 72%, respectively. With regard to lactic acid concentration, and sugar consumption, the results revealed that the single culture ATCC 393 produced the optimum lactic acid of 87 g/l for 48 hr with initial sugar concentration of 90 g/l.展开更多
In this study,the feasibility of producing eco-friendly bricks by using geopolymer technology and a waste grinding wheel(WGW)from the grinding wheel industries was investigated.Nowadays,in order to meet industrial nee...In this study,the feasibility of producing eco-friendly bricks by using geopolymer technology and a waste grinding wheel(WGW)from the grinding wheel industries was investigated.Nowadays,in order to meet industrial needs,for instance,in Taiwan,approximately 500,000 grinding wheels are used annually.That is,a large number of“waste”grinding wheels are produced.Furthermore,few studies have been conducted on the use of WGWs as raw materials in geopolymer applications.The use of geopolymer technology to form bricks can avoid the utilization of clay and cement and even prevent the use of a high-temperature process in kilns.Moreover,it can decrease CO_(2) emission and energy consumption and thus,protect the environment.In this study,the following three major factors were considered:press-forming pressure(70 and 100 kgf/cm2),NaOH molar concentration(2 and 4M),and the ratio of binder fineaggregate(1:3,1:4,and 1:5).Under these conditions,the specimens were tested using the compressive strength test,water absorption test,microstructure analysis,a freezing–thawing test and toxicity characteristic leaching procedure test.The optimal formulation was composed of 1:4 binder fine-aggregate ratio,4M NaOH concentration,and 100-kgf/cm2 pressure.Furthermore,we used a WGW and achieved a compressive strength of 50.6 MPa after 28 days,which was greater than 32 MPa and conformed to the Grade A brick standard of National Standards of the Republic of China(13295).In conclusion,this brick fabrication method based on geopolymer technology was not only beneficial to the environment but also improved the efficiency of reutilizing WGW.展开更多
A hydrogen liquefaction concept with an innovative configuration and a capacity of 4 kg·s^(-1)(345.6 t·d^(-1))is developed.The concept involves an ammonia absorption refrigeration system for the pre-cooling ...A hydrogen liquefaction concept with an innovative configuration and a capacity of 4 kg·s^(-1)(345.6 t·d^(-1))is developed.The concept involves an ammonia absorption refrigeration system for the pre-cooling of hydrogen and MR streams from 25℃ to-30℃.The ammonia absorption refrigeration system is fed by exhaust gases of the Pa rand gas power plant that are normally dissipated to the environment with a temperature of 546℃.The simulation is performed by Aspen HYSYS V9.0,using two separate equations of state for simulating hydrogen and MR streams to gain more accurate results especially for ortho-para conversion.Results show that conversion enthalpy estimated by Aspen HYSYS,fits very well to the experimental data.Determining the important independent variables and composition of MRs are done using trial and error procedure,a functional and straightforward method for complicated systems.The minimum temperature limit in the cooling section is lowered,and an ortho-para converter is implemented in this section.The proposed concept performs well from energy aspects and leads to COP and SEC equal to 0.271 and 4.54 kW·h·kg^(-1),respectively.The main advantage of this study is in the low SEC,eliminating the losses of the distribution network,and improving the ability of the hydrogen liquefaction for energy storage in off-peak times.展开更多
Wasting has been observed as a common feature of the human immunodeficiency virus (HIV) disease since the first reports and its presence increases the risk of death. There is no consensus on how to manage wasting asso...Wasting has been observed as a common feature of the human immunodeficiency virus (HIV) disease since the first reports and its presence increases the risk of death. There is no consensus on how to manage wasting associated with HIV. The goal of this study was to assess the effectiveness of a locally made Chickpea Sesame Based RUTF (CS-RUTF) in treating wasting associated with HIV in developing countries. Chronically sick adults from Mangochi Health District (Malawi) with wasting and confirmed or presumptive clinical diagnosis of HIV were recruited for the study. Subjects received a daily ration of 500 grams of CS-RUTF for 3 to 5 months. Nutrition status changes and mortality were used to assess the effectiveness of the intervention. There were 3 patterns of anthropometric responses continuous weight gain (WG), static weight (SW) and continuation weight loss (WL). The distribution of the 3 patterns is 53.9% (82/154) for the WG pattern, 9.1% (14/154) for the SW pattern and 37.0% (57/154) for the WL pattern. For the WG pattern, the overall median weight gain was 4.6 (2.4 to 7.1) kg. It was 5.7 (3.5 to 7.8) kg for those who completed 3 months of sup-plementation. MUAC and BMI changes followed similar pattern than weight change. Not being on HAART, acute diarrhoea during follow up, episode of reduced appetite during follow up, missing at least one visit were identified as risk factors for intervention failure. Overall, 38.5% (72/187) of study participants died during the intervention. In conclusion, despite that the study confirms the limited impact of food based interventions on mortality among wasted HIV positive individuals, it also suggests that supplementation with CS-RUTF may be an effective intervention for reversing wasting associated with HIV if combined with HAART and specific treatment of severe opportunistic infection causing diarrhoea and reducing appetite.展开更多
The collected tungsten carbide/cobalt scrapped waste typically contains approximately 90% tungsten carbide and 10% cobalt.A nitric method is used to extract tungsten and cobalt from tungsten-containing waste.The waste...The collected tungsten carbide/cobalt scrapped waste typically contains approximately 90% tungsten carbide and 10% cobalt.A nitric method is used to extract tungsten and cobalt from tungsten-containing waste.The waste is first dissolved in nitric acid,which then makes cobalt soluble and becomes cobalt nitrate solution.The waste also oxidizes tungsten carbide to insoluble tungstenic acid precipitate.If tungsten carbide scraps are obtained from leftover of LCD glass cutting,after applying the same process as above,the remaining glass also needs to be separated from the tungstenic acid.XRF analysis shows that 93.8% of cobalt and 97.72% of tungsten can be obtained separately by this wet chemical method.By ICP analysis,no more tungsten ion remains after 2 h reaction in the cobalt recovery when 12 N of nitric acid is used for oxidation.The recovery materials obtained for tungsten are tungsten oxide and for cobalt a mixture of Co3O4 and CoO.展开更多
Waste printed circuit boards(WPCBs)are hazardous solid wastes that are composed of various metal and non-metal materials.Pyrolysis has long been regarded as an environmentally friendly and promising application techno...Waste printed circuit boards(WPCBs)are hazardous solid wastes that are composed of various metal and non-metal materials.Pyrolysis has long been regarded as an environmentally friendly and promising application technology for recovering organic and inorganic materials from the WPCBs.The pyrolysis atmosphere and co-existing materials are critical factors that significantly influence the pyrolysis behavior.To compare the specific effects of these factors on the pyrolysis characteristics of the WPCBs,a series of thermogravimetric and kinetics analyses has been conducted.It was then found that the apparent activation energy was reduced when pyrolyzed in CO_(2)or co-pyrolyzed with glass fibers,which was supposed to result from the enhanced diffusion and phase boundary reactions.In contrast,an increase in the apparent activation energy was observed at the early stage of the co-pyrolysis with Cu,which was inferred to be associated with the Cu-catalyzed cross-linking effects.Specifically,the formed coke might adsorb pyrolysis products and inhibit the diffusion and reduce the reactive phase boundary.Previous studies have primarily focused on the catalysis of metals in the pyrolysis of WPCBs,while other interactions as well as the kinetic effects of glass fibers and pyrolysis atmospheres have received less discussion.The study presented a comprehensive investigation of the roles played by the pyrolysis atmosphere and co-existing materials in the pyrolysis of the WPCBs.It showed that these factors could alter the reaction-controlling mechanisms by complex interactions.These findings can provide new mechanistic insights and contribute to the use and optimization of pyrolysis-based recycling technologies.展开更多
There is growing global concern over food waste and its impacts on resources, environmental issues and food security, especially in developing countries. However, knowledge of food waste, in particular, the food waste...There is growing global concern over food waste and its impacts on resources, environmental issues and food security, especially in developing countries. However, knowledge of food waste, in particular, the food wasted by consumers in restaurants, is entirely inadequate in China. Here, based on media reports and documents about food waste we provide an overview of food wasted by consumers in restaurants in China. We roughly estimated total food waste in order to uncover the seriousness of this large issue. We collected international literature referring to food waste and provided a detailed explanation of the resources and environmental costs associated with food waste. Ultimately we propose a conceptual diagram on research into catering food waste by consumers to evaluate resources and environmental costs based on life cycle assessment in China. This work will stimulate interdisciplinary research in this field.展开更多
Currently,the gradual depletion of fossil resources and the large amount of plastic waste are causing serious harm to the land and marine ecology.The rapid development of wearable smart fibers is accompanied by rapid ...Currently,the gradual depletion of fossil resources and the large amount of plastic waste are causing serious harm to the land and marine ecology.The rapid development of wearable smart fibers is accompanied by rapid growth in the material demand for fibers,and the development of green and high-performance biomass-based fibers has become an important research topic to reduce the dependence on synthetic fiber materials and the harm to the environment.Here,chitosan is first prepared from the waste material by chemical methods.Then the chitosan-based self-powered induction fibers are prepared by electrospinning core wire technique.Chitosan-based self-powered sensing fiber is ultra-light and flexible,which can achieve about 2500 collisions without damaging the surface.Chitosan-based self-powered sensing fiber can also be used in smart home sensing applications to control home appliance switches with a light touch,which has a great application prospect in smart home and wearable fields.展开更多
The global energy landscape is undergoing a profound transformation,with wind energy,especially wind power,gaining increasing prominence due to its clean,renewable nature.However,as the installed capacity of wind powe...The global energy landscape is undergoing a profound transformation,with wind energy,especially wind power,gaining increasing prominence due to its clean,renewable nature.However,as the installed capacity of wind power continues to expand,the disposal of waste wind turbine blades(WWTB)has emerged as a significant challenge.These blades are predominantly composed of epoxy resin(EP)polymers,carbon fibers(CFs),and glass fibers(GFs).Improper disposal not only exacerbates environmental concerns but also leads to the loss of valuable resources,particularly carbon-based materials.Pyrolysis technology,a versatile and environmentally sustainable method for resource recovery,has garnered considerable attention in the context of WWTB disposal.This work presents a comprehensive review of the pyrolytic recycling of WWTB,focusing on the principles and classifications of pyrolysis technology,key factors influencing the pyrolysis process,as well as the pyrolysis methods,equipment,products,and their applications.Through an in-depth analysis of the current research on the pyrolytic recycling of WWTB,this review identifies critical unresolved issues in the field and provides a forward-looking perspective on emerging research trends.展开更多
Combustion of herb residues(HRs)for heat recovery is a good way for their utilization,but there exists such a problem as high concentration NOx emission in flue gas.The alcohol extracted herb residue(AEHR),one special...Combustion of herb residues(HRs)for heat recovery is a good way for their utilization,but there exists such a problem as high concentration NOx emission in flue gas.The alcohol extracted herb residue(AEHR),one special type of HRs,was chosen as the object and was subjected to immediate combustion in a fluidized bed reactor to investigate the characteristics of its resulting NOx emission.The results showed that,most of the NOx in the flue gas was produced from the char nitrogen(C-N);as the fuel water content increased,the NOx emission concentration exhibited a trend of first decreasing and then increasing;and a properly low combustion temperature inhibited the NOx emission upon the premise of ensuring full combustion.Air staging combustion was adopted to effectively control NOx:the NOx emission concentration in the flue gas was reduced to 296 mg⋅m3 and the NOx emission reduction rate reached 46.51%compared to conventional combustion.Co-combustion by blending wasted activated coke(WAC)into the AEHR helped both stabilize the combustion state and reduce further the NOx emission.When the blending ratio of WAC fell within a proper range of 20-30%,the NOx emission concentration in the flue gas was as low as 231.4 mg⋅m3.In addition to the dilution effect of the combustion flue gas of the blended WAC,the local reducing atmosphere caused by its incomplete combustion as well as its strong absorbability and catalytical effect was accountable for the further decrease of the NOx emission concentration.展开更多
Long-life pavement has been introduced to address the urgent need for durable and reliable transportation infrastructure.This review overviews the development of aggregates for long-life pavements and summarizes futur...Long-life pavement has been introduced to address the urgent need for durable and reliable transportation infrastructure.This review overviews the development of aggregates for long-life pavements and summarizes future research directions.The review indicates that natural aggregates,being non-renewable resources,are steadily declining in availability and may need to meet future demands.Construction solid waste aggregates are rapidly developing,with fine separation of reclaimed asphalt pavement(RAP)and reinforcement of cementbased recycled aggregates serving as key strategies to enhance their application.Industry solid waste aggregates possess properties suitable for long-life pavements and offer additional functionalities such as cooling,conductivity,and reflectivity,demonstrating significant development potential.While artificial aggregates exhibit superior performance,their large-scale application requires consideration of economic and environmental impacts.Current aggregate evaluation methods need to address the needs of long-life pavements.Aggregate performance requirements should be graded based on mechanical stress and temperature distribution,with corresponding evaluation methods and indices developed.Evaluating the mechanical properties of aggregates should align more closely with actual stress states.Tests such as triaxial,repeated load,and wheel abrasion polishing are better suited for assessing the strength and durability of long-life pavement aggregates.Similarly,evaluating aggregates'physicochemical properties should be based on studies correlating these properties with road performance,with proposed evaluation criteria.Morphological characteristics of aggregates significantly influence asphalt mixture performance,and efficient evaluation of their profile,angularity,and texture will be a key focus of future research.展开更多
Waste graphitization cathode carbon blocks are a type of hazardous solid waste generated during the aluminum electrolysis process,and their proper disposal is a key step in the resource utilization of discarded graphi...Waste graphitization cathode carbon blocks are a type of hazardous solid waste generated during the aluminum electrolysis process,and their proper disposal is a key step in the resource utilization of discarded graphite.This study utilizes the porous“defect advantage”of a cathode carbon block matrix to prepare silicon-doped and asphalt-coated detoxified and purified waste graphitization cathode carbon blocks for use as high-performance silicon/carbon composite anode materials.The results show that the uniformly silicondoped silicon/carbon composite material features a unique amorphous carbon-encapsulated“locked silicon”structure,which effectively addresses issues such as cathode volume expansion,excessive growth of the solid electrolyte interphase(SEI)film,and poor electrical contact between active materials.Consequently,electrochemical performance is enhanced.After assembly in a half-cell,the PSCC/10%Si@C(purified waste graphitization cathode carbon/10%Si@C)material exhibits optimal electrochemical stability,with an initial charging specific capacity of 514.5 mAh/g at 0.1 C(1 C=170 mA/g)and a capacity retention rate of 95.1%after 100 cycles.At a charge rate of 2.0 C,a specific capacity of 216.9 mAh/g is achieved.This technology provides a new pathway for the economical and high-value utilization of waste cathode carbon blocks and the development of low-cost,high-performance anode materials.展开更多
This study investigates the performance enhancement of super-sulfated cement(SSC)derived from arsenic-containing bio-oxidation waste(BW)through the incorporation of carbonated recycled concrete fines(CRCF).The finding...This study investigates the performance enhancement of super-sulfated cement(SSC)derived from arsenic-containing bio-oxidation waste(BW)through the incorporation of carbonated recycled concrete fines(CRCF).The findings revealed that the addition of 5wt%CRCF yields optimal performance,with compressive strengths reaching approximately 1.83,12.59,and 42.81 MPa at 1,3,and 28 d,respectively.These values represented significant increases of 408.3%,10.0%,and 14.3%compared to the reference sample.The improvement was attributed to the synergistic effects of ultrafine CRCF particles acting as fillers and nucleation sites,as well as the high reactivity of silica gels,which promoted the formation of additional hydration gels.Microstructural analysis confirmed that CRCF addition refined pore structure,and enhanced the stiffness of C-S-H gels.Furthermore,CRCF served as a net CO_(2) sink,sequestering 0.268 kg CO_(2) per kilogram of CRCF and thereby reducing the carbon footprint of SSC.In addition,the feasibility of applying CRCF-modified SSC in cemented paste backfill(CPB)is highlighted,given the high cement-related carbon footprint of conventional CPB.When 5wt%CRCFmodified SSC was employed in CPB,its 3-d compressive strength attained over 70%of that of ordinary Portland cement(OPC),while the 28-d strength was comparable to that of OPC.The proposed binder thus provides a sustainable pathway for BW valorization,combining waste utilization,carbon sequestration,and improved engineering performance.展开更多
Recycling of waste rubber(WR)is crucial for the sustainable development of the rubber industry.The enhancement of interfacial interactions is the main strategy for waste polymer recycling.However,there is a lack of me...Recycling of waste rubber(WR)is crucial for the sustainable development of the rubber industry.The enhancement of interfacial interactions is the main strategy for waste polymer recycling.However,there is a lack of methods for enhancing the interfacial interactions for WR recycling because WR contains abundant inert C―H bonds.Herein,we designed thioctic acid inverse vulcanization copolymers to endow recycled WR with dynamic disulfide interfacial interactions,significantly improving the mechanical properties of recycled WR.These disulfide interfacial interactions among the recycled WR tend to exchange,which dramatically increases the fractocohesive length and prevents stress concentration near the crack tips.When recycled WR is subjected to external stress,the loads are redistributed across a broad region of adjacent regions instead of being concentrated on a limited length scale,which resists crack propagation.This work effectively recycled WR,providing a strategy for solvent-free reaction-derived inverse vulcanization copolymers to improve the toughness of WR recycling.展开更多
文摘This applied research seeks to explore feasible plant design for manufacturing insulation materials for construction projects using waste sheep fleece to address environmental issues related to wasted sheep wool and enhance the gross national product. The process starts by collecting low-cost sheep fleece from farms and processed via a production line, including scouring, plucking, carding, thermal bonding, and packing. The design process involves determining an optimal location, infrastructure, staffing, machinery, environmental impact, and utilities. A final economic analysis is undertaken to estimate the product’s cost, selling price, and break-even point based on the anticipated capital and operational costs. The plant is intended to process 6778 tons of sheep wool annually. The study suggests that Mafraq Industrial City is a perfect location for the plant, and purchasing land and structures is the optimal option. The projected capital cost is 1,416,679 USD, while the anticipated operational costs amount to 3,206,275 USD. Insulation material production is estimated to be 114,756 m3 annually. The material may be manufactured into 1 m wide, 0.05 m thick sheets for 2.02 USD per square meter. Thus, for a 10-year plant, a 2.47 USD/m2 selling price breaks even in one year.
基金support from the National Natural Science Foundation of China (22108307)。
文摘The direct emission of waste refinery gas after combustion will cause a severe greenhouse effect.Recovering high-value-added ethylene from wasted refinery gas has fundamental economic and environmental significance. Due to the complexity of the composition of refinery waste gas, designing and optimizing the whole recovery process is still a challenging task. Herein, a novel process(SCOAS) was proposed to obtain polymer-grade ethylene from wasted refinery gas through a direct separation process,and heat pump-assisted thermal integration optimization(HPSCOAS) was carried out. The unique feature of the novel approach is that a new stripper and ethylene reabsorber follow the dry gas absorber to ensure ethylene recovery and methane content. An industrial model, shallow cooling oil absorption(SCOA), and concentration combined cold separation system of ethylene unit using wasted refinery gas was established to analyze the technology and environment. Based on the detailed process modeling and simulation results, the quantitative sustainability assessment of economy and environment based on product life cycle process is carried out. The results show that compared with the traditional process when the same product is obtained, the total annual cost of the HPSCOAS process is the lowest, which is 15.4% lower than that of the SCOA process and 6.1% lower than that of the SCOAS process. In addition,compared with the SCOA process and the HPSCOAS process, the SCOAS process has more environmental advantages. The non-renewable energy consumed by SCOAS is reduced by about 24.8% and 6.1%, respectively. The CO_(2) equivalent is reduced by about 38.6% and 23.7%.
文摘An old automotive industrial site located at Mexico City with many years of operation and contaminated with heavy oil hydrocarbons, particularly spent oils, was assessed for restoration using the surfactant enhanced soil washing (SESW) process. The main goal of this study was to characterize the contaminated soil in terms of TPHs, BTEX, PAHs, and metals contents as well as microbiologically (total heterotrophs and specific degrading microorganisms). We also aimed to determine the surfactant type and concentration to be used in the SESW process for the automotive waste oil contaminated soil. At the end, sixteen kg of contaminated soil were washed and the produced wastewater (approximately 40 L) was characterized in terms of COD, BOD;solids, and other physico-chemical parameters. The soil contained about 14,000 mg of TPH/kg soil (heavy fraction), 0.13 mg/kg of benzo (k) fluoranthene and 0.07 mg/kg of benzo (a) pyrene as well as traces of some metals. Metals concentrations were always under the maximum concentration levels suggested by Mexican regulations. 15 different surfactants were used to identify the one with the capability to achieve the highest TPH removal. Surfactants included 5 anionics, 2 zwitterionic, 5 nonionics and 3 natural gums. Sulfopon 30 at a concentration of 0.5% offered the best surfactant performance. The TPH removals employing the different surfactants were in the range from 38% to 68%, in comparison to the soil washing with water (10% of TPH removal). Once the surfactant was selected, 70 kg of soil were washed and the resulting water contained approximately 1300 mg/L of COD, 385 mg/L of BOD (BOD/COD = 0.29), 122 mg/L of MBAS, and 212 mg/L of oil and greases, among other contaminants.
文摘In the global environment of pursuing resource regeneration and green environmental protection, more and more wasted clothing need to be solved. In order to make full use of the wasted clothing and save land and soil resources, an idea of wasted clothing's recycling and remanufacturing is put forward. In the new idea a pricing game model is established basing on Stacklberg differential game theory between traditional and remanufactured clothing. In this model, the differences in consumers' willingness to pay and the government's subsidies are considered. Government's optimal subsidy are obtained which ensure not only the interests of manufacturers but also environmental reputation and maximum social benefits. The study is helpful to push the wasted clothing's recycling and remanufacturing plan. It makes some index more precise quantification as government's subsidy, manufacturers and the social benefits. Government and manufactures can make the detailed cooperation plan reference to it.
文摘Electronic scrap, especially wasted printed circuit boards (PCBs), is regarded as an environmental challenge. At present, the physical separation is thought to be the environmental friendly and economical method of treating and reutilizing electronic waste. An effective liberation of metals from non metallic components is a crucial step towards mechanical separation and recycling of wasted PCBs. In this paper, the selective shredding theory and mechanics characteristics of wasted PCBs were analyzed, and the shredded experiments of wasted PCBs by hammer mill were investigated. The result shows that the selective shredding exists in the wasted PCBs shredded process by hammer mill. The shredding velocity of non metallic components is far greater than that of metals in the wasted PCBs shredding, which makes the metals concentrate in the coarser fraction. And the impact force of hammer mill is superior to metal liberation from non metallic components, a satisfied metal liberation degree can be achieved in the wasted PCBs shredding by hammer mill.
文摘The Kingdom of Saudi Arabia produces over one million metric tons annually, which returns a 20% of wasted dates annually. Lactic acid and its derivatives are widely used in food, pharmaceutical and textile industries. There has been an increase in lactic acid production because it is used as a raw material to produce polylactic acid, a polymer that is used as a special medical and environmental friendly biodegradable plastic. This study aimed to use wasted dates to produce lactic acid by single culture Lactobacillus casei (ATCC 393), Lactobacillus acidophilus (CICC 6088) and the mixed culture using batch fermentation. The investigation results showed that the maximum concentration of lactic acid for ATCC 393, CICC 6088 and the mixed culture are 87, 84 and 84 g/l respectively. For single CICC 6088 and the mixed culture, the total percentage of glucose and fructose utilized was found to be 100%;76%, respectively, whereas in the case of the single culture ATCC 393, the total percentage of glucose and fructose were 100% and 72%, respectively. With regard to lactic acid concentration, and sugar consumption, the results revealed that the single culture ATCC 393 produced the optimum lactic acid of 87 g/l for 48 hr with initial sugar concentration of 90 g/l.
文摘In this study,the feasibility of producing eco-friendly bricks by using geopolymer technology and a waste grinding wheel(WGW)from the grinding wheel industries was investigated.Nowadays,in order to meet industrial needs,for instance,in Taiwan,approximately 500,000 grinding wheels are used annually.That is,a large number of“waste”grinding wheels are produced.Furthermore,few studies have been conducted on the use of WGWs as raw materials in geopolymer applications.The use of geopolymer technology to form bricks can avoid the utilization of clay and cement and even prevent the use of a high-temperature process in kilns.Moreover,it can decrease CO_(2) emission and energy consumption and thus,protect the environment.In this study,the following three major factors were considered:press-forming pressure(70 and 100 kgf/cm2),NaOH molar concentration(2 and 4M),and the ratio of binder fineaggregate(1:3,1:4,and 1:5).Under these conditions,the specimens were tested using the compressive strength test,water absorption test,microstructure analysis,a freezing–thawing test and toxicity characteristic leaching procedure test.The optimal formulation was composed of 1:4 binder fine-aggregate ratio,4M NaOH concentration,and 100-kgf/cm2 pressure.Furthermore,we used a WGW and achieved a compressive strength of 50.6 MPa after 28 days,which was greater than 32 MPa and conformed to the Grade A brick standard of National Standards of the Republic of China(13295).In conclusion,this brick fabrication method based on geopolymer technology was not only beneficial to the environment but also improved the efficiency of reutilizing WGW.
文摘A hydrogen liquefaction concept with an innovative configuration and a capacity of 4 kg·s^(-1)(345.6 t·d^(-1))is developed.The concept involves an ammonia absorption refrigeration system for the pre-cooling of hydrogen and MR streams from 25℃ to-30℃.The ammonia absorption refrigeration system is fed by exhaust gases of the Pa rand gas power plant that are normally dissipated to the environment with a temperature of 546℃.The simulation is performed by Aspen HYSYS V9.0,using two separate equations of state for simulating hydrogen and MR streams to gain more accurate results especially for ortho-para conversion.Results show that conversion enthalpy estimated by Aspen HYSYS,fits very well to the experimental data.Determining the important independent variables and composition of MRs are done using trial and error procedure,a functional and straightforward method for complicated systems.The minimum temperature limit in the cooling section is lowered,and an ortho-para converter is implemented in this section.The proposed concept performs well from energy aspects and leads to COP and SEC equal to 0.271 and 4.54 kW·h·kg^(-1),respectively.The main advantage of this study is in the low SEC,eliminating the losses of the distribution network,and improving the ability of the hydrogen liquefaction for energy storage in off-peak times.
文摘Wasting has been observed as a common feature of the human immunodeficiency virus (HIV) disease since the first reports and its presence increases the risk of death. There is no consensus on how to manage wasting associated with HIV. The goal of this study was to assess the effectiveness of a locally made Chickpea Sesame Based RUTF (CS-RUTF) in treating wasting associated with HIV in developing countries. Chronically sick adults from Mangochi Health District (Malawi) with wasting and confirmed or presumptive clinical diagnosis of HIV were recruited for the study. Subjects received a daily ration of 500 grams of CS-RUTF for 3 to 5 months. Nutrition status changes and mortality were used to assess the effectiveness of the intervention. There were 3 patterns of anthropometric responses continuous weight gain (WG), static weight (SW) and continuation weight loss (WL). The distribution of the 3 patterns is 53.9% (82/154) for the WG pattern, 9.1% (14/154) for the SW pattern and 37.0% (57/154) for the WL pattern. For the WG pattern, the overall median weight gain was 4.6 (2.4 to 7.1) kg. It was 5.7 (3.5 to 7.8) kg for those who completed 3 months of sup-plementation. MUAC and BMI changes followed similar pattern than weight change. Not being on HAART, acute diarrhoea during follow up, episode of reduced appetite during follow up, missing at least one visit were identified as risk factors for intervention failure. Overall, 38.5% (72/187) of study participants died during the intervention. In conclusion, despite that the study confirms the limited impact of food based interventions on mortality among wasted HIV positive individuals, it also suggests that supplementation with CS-RUTF may be an effective intervention for reversing wasting associated with HIV if combined with HAART and specific treatment of severe opportunistic infection causing diarrhoea and reducing appetite.
基金Supported by the project of National Science Council in Taiwan(No.:NSC-95-2622-E-159)
文摘The collected tungsten carbide/cobalt scrapped waste typically contains approximately 90% tungsten carbide and 10% cobalt.A nitric method is used to extract tungsten and cobalt from tungsten-containing waste.The waste is first dissolved in nitric acid,which then makes cobalt soluble and becomes cobalt nitrate solution.The waste also oxidizes tungsten carbide to insoluble tungstenic acid precipitate.If tungsten carbide scraps are obtained from leftover of LCD glass cutting,after applying the same process as above,the remaining glass also needs to be separated from the tungstenic acid.XRF analysis shows that 93.8% of cobalt and 97.72% of tungsten can be obtained separately by this wet chemical method.By ICP analysis,no more tungsten ion remains after 2 h reaction in the cobalt recovery when 12 N of nitric acid is used for oxidation.The recovery materials obtained for tungsten are tungsten oxide and for cobalt a mixture of Co3O4 and CoO.
基金supported by the National Natural Science Foundation of China(Nos.52270132 and U20A20273).
文摘Waste printed circuit boards(WPCBs)are hazardous solid wastes that are composed of various metal and non-metal materials.Pyrolysis has long been regarded as an environmentally friendly and promising application technology for recovering organic and inorganic materials from the WPCBs.The pyrolysis atmosphere and co-existing materials are critical factors that significantly influence the pyrolysis behavior.To compare the specific effects of these factors on the pyrolysis characteristics of the WPCBs,a series of thermogravimetric and kinetics analyses has been conducted.It was then found that the apparent activation energy was reduced when pyrolyzed in CO_(2)or co-pyrolyzed with glass fibers,which was supposed to result from the enhanced diffusion and phase boundary reactions.In contrast,an increase in the apparent activation energy was observed at the early stage of the co-pyrolysis with Cu,which was inferred to be associated with the Cu-catalyzed cross-linking effects.Specifically,the formed coke might adsorb pyrolysis products and inhibit the diffusion and reduce the reactive phase boundary.Previous studies have primarily focused on the catalysis of metals in the pyrolysis of WPCBs,while other interactions as well as the kinetic effects of glass fibers and pyrolysis atmospheres have received less discussion.The study presented a comprehensive investigation of the roles played by the pyrolysis atmosphere and co-existing materials in the pyrolysis of the WPCBs.It showed that these factors could alter the reaction-controlling mechanisms by complex interactions.These findings can provide new mechanistic insights and contribute to the use and optimization of pyrolysis-based recycling technologies.
文摘There is growing global concern over food waste and its impacts on resources, environmental issues and food security, especially in developing countries. However, knowledge of food waste, in particular, the food wasted by consumers in restaurants, is entirely inadequate in China. Here, based on media reports and documents about food waste we provide an overview of food wasted by consumers in restaurants in China. We roughly estimated total food waste in order to uncover the seriousness of this large issue. We collected international literature referring to food waste and provided a detailed explanation of the resources and environmental costs associated with food waste. Ultimately we propose a conceptual diagram on research into catering food waste by consumers to evaluate resources and environmental costs based on life cycle assessment in China. This work will stimulate interdisciplinary research in this field.
基金The authors are grateful for the support received from National Natural Science Foundation of China(Grant No.22109012)Natural Science Foundation of the Beijing Municipality(Grant No.2212052)the Fundamental Research Funds for the Central Universities(Grant No.E1E46805).
文摘Currently,the gradual depletion of fossil resources and the large amount of plastic waste are causing serious harm to the land and marine ecology.The rapid development of wearable smart fibers is accompanied by rapid growth in the material demand for fibers,and the development of green and high-performance biomass-based fibers has become an important research topic to reduce the dependence on synthetic fiber materials and the harm to the environment.Here,chitosan is first prepared from the waste material by chemical methods.Then the chitosan-based self-powered induction fibers are prepared by electrospinning core wire technique.Chitosan-based self-powered sensing fiber is ultra-light and flexible,which can achieve about 2500 collisions without damaging the surface.Chitosan-based self-powered sensing fiber can also be used in smart home sensing applications to control home appliance switches with a light touch,which has a great application prospect in smart home and wearable fields.
基金Supported by the National Natural Science Foundation of China(22468035,22468036,22368038,22308048)the Natural Science Foundation of Inner Mongolia(2024QN02018,2025MS02030)+2 种基金First-class Discipline Research Special Project of Inner Mongolia(YLXKZX-NGD-045)Inner Mongolia Autonomous Region Postgraduate Research Innovation Project(KC2024047B)Research Foundation for Introducing High-level Talents in Inner Mongolia Autonomous Region。
文摘The global energy landscape is undergoing a profound transformation,with wind energy,especially wind power,gaining increasing prominence due to its clean,renewable nature.However,as the installed capacity of wind power continues to expand,the disposal of waste wind turbine blades(WWTB)has emerged as a significant challenge.These blades are predominantly composed of epoxy resin(EP)polymers,carbon fibers(CFs),and glass fibers(GFs).Improper disposal not only exacerbates environmental concerns but also leads to the loss of valuable resources,particularly carbon-based materials.Pyrolysis technology,a versatile and environmentally sustainable method for resource recovery,has garnered considerable attention in the context of WWTB disposal.This work presents a comprehensive review of the pyrolytic recycling of WWTB,focusing on the principles and classifications of pyrolysis technology,key factors influencing the pyrolysis process,as well as the pyrolysis methods,equipment,products,and their applications.Through an in-depth analysis of the current research on the pyrolytic recycling of WWTB,this review identifies critical unresolved issues in the field and provides a forward-looking perspective on emerging research trends.
基金supported by the National Key Research and Development Program of China(Grant No.2019YFC1906805).
文摘Combustion of herb residues(HRs)for heat recovery is a good way for their utilization,but there exists such a problem as high concentration NOx emission in flue gas.The alcohol extracted herb residue(AEHR),one special type of HRs,was chosen as the object and was subjected to immediate combustion in a fluidized bed reactor to investigate the characteristics of its resulting NOx emission.The results showed that,most of the NOx in the flue gas was produced from the char nitrogen(C-N);as the fuel water content increased,the NOx emission concentration exhibited a trend of first decreasing and then increasing;and a properly low combustion temperature inhibited the NOx emission upon the premise of ensuring full combustion.Air staging combustion was adopted to effectively control NOx:the NOx emission concentration in the flue gas was reduced to 296 mg⋅m3 and the NOx emission reduction rate reached 46.51%compared to conventional combustion.Co-combustion by blending wasted activated coke(WAC)into the AEHR helped both stabilize the combustion state and reduce further the NOx emission.When the blending ratio of WAC fell within a proper range of 20-30%,the NOx emission concentration in the flue gas was as low as 231.4 mg⋅m3.In addition to the dilution effect of the combustion flue gas of the blended WAC,the local reducing atmosphere caused by its incomplete combustion as well as its strong absorbability and catalytical effect was accountable for the further decrease of the NOx emission concentration.
基金sponsored by the National Natural Science Foundation of China(52178420,52408476)Research Project of Liaoning Provincial Transportation Construction Investment Group Co.,Ltd.(202410)+1 种基金Postdoctoral Fellowship Program of CPSF(GZC20242207)the Fundamental Research Funds for the Central Universities(HIT.DZJJ.2023086).
文摘Long-life pavement has been introduced to address the urgent need for durable and reliable transportation infrastructure.This review overviews the development of aggregates for long-life pavements and summarizes future research directions.The review indicates that natural aggregates,being non-renewable resources,are steadily declining in availability and may need to meet future demands.Construction solid waste aggregates are rapidly developing,with fine separation of reclaimed asphalt pavement(RAP)and reinforcement of cementbased recycled aggregates serving as key strategies to enhance their application.Industry solid waste aggregates possess properties suitable for long-life pavements and offer additional functionalities such as cooling,conductivity,and reflectivity,demonstrating significant development potential.While artificial aggregates exhibit superior performance,their large-scale application requires consideration of economic and environmental impacts.Current aggregate evaluation methods need to address the needs of long-life pavements.Aggregate performance requirements should be graded based on mechanical stress and temperature distribution,with corresponding evaluation methods and indices developed.Evaluating the mechanical properties of aggregates should align more closely with actual stress states.Tests such as triaxial,repeated load,and wheel abrasion polishing are better suited for assessing the strength and durability of long-life pavement aggregates.Similarly,evaluating aggregates'physicochemical properties should be based on studies correlating these properties with road performance,with proposed evaluation criteria.Morphological characteristics of aggregates significantly influence asphalt mixture performance,and efficient evaluation of their profile,angularity,and texture will be a key focus of future research.
基金supported by the National Natural Science Foundation of China(No.52274346).
文摘Waste graphitization cathode carbon blocks are a type of hazardous solid waste generated during the aluminum electrolysis process,and their proper disposal is a key step in the resource utilization of discarded graphite.This study utilizes the porous“defect advantage”of a cathode carbon block matrix to prepare silicon-doped and asphalt-coated detoxified and purified waste graphitization cathode carbon blocks for use as high-performance silicon/carbon composite anode materials.The results show that the uniformly silicondoped silicon/carbon composite material features a unique amorphous carbon-encapsulated“locked silicon”structure,which effectively addresses issues such as cathode volume expansion,excessive growth of the solid electrolyte interphase(SEI)film,and poor electrical contact between active materials.Consequently,electrochemical performance is enhanced.After assembly in a half-cell,the PSCC/10%Si@C(purified waste graphitization cathode carbon/10%Si@C)material exhibits optimal electrochemical stability,with an initial charging specific capacity of 514.5 mAh/g at 0.1 C(1 C=170 mA/g)and a capacity retention rate of 95.1%after 100 cycles.At a charge rate of 2.0 C,a specific capacity of 216.9 mAh/g is achieved.This technology provides a new pathway for the economical and high-value utilization of waste cathode carbon blocks and the development of low-cost,high-performance anode materials.
基金supports from the National Natural Science Foundation of China(No.52304148)the Youth Project of Shanxi Basic Research Program(No.202203021212262).
文摘This study investigates the performance enhancement of super-sulfated cement(SSC)derived from arsenic-containing bio-oxidation waste(BW)through the incorporation of carbonated recycled concrete fines(CRCF).The findings revealed that the addition of 5wt%CRCF yields optimal performance,with compressive strengths reaching approximately 1.83,12.59,and 42.81 MPa at 1,3,and 28 d,respectively.These values represented significant increases of 408.3%,10.0%,and 14.3%compared to the reference sample.The improvement was attributed to the synergistic effects of ultrafine CRCF particles acting as fillers and nucleation sites,as well as the high reactivity of silica gels,which promoted the formation of additional hydration gels.Microstructural analysis confirmed that CRCF addition refined pore structure,and enhanced the stiffness of C-S-H gels.Furthermore,CRCF served as a net CO_(2) sink,sequestering 0.268 kg CO_(2) per kilogram of CRCF and thereby reducing the carbon footprint of SSC.In addition,the feasibility of applying CRCF-modified SSC in cemented paste backfill(CPB)is highlighted,given the high cement-related carbon footprint of conventional CPB.When 5wt%CRCFmodified SSC was employed in CPB,its 3-d compressive strength attained over 70%of that of ordinary Portland cement(OPC),while the 28-d strength was comparable to that of OPC.The proposed binder thus provides a sustainable pathway for BW valorization,combining waste utilization,carbon sequestration,and improved engineering performance.
基金financially supported by the National Natural Science Foundation of China(No.52363007)。
文摘Recycling of waste rubber(WR)is crucial for the sustainable development of the rubber industry.The enhancement of interfacial interactions is the main strategy for waste polymer recycling.However,there is a lack of methods for enhancing the interfacial interactions for WR recycling because WR contains abundant inert C―H bonds.Herein,we designed thioctic acid inverse vulcanization copolymers to endow recycled WR with dynamic disulfide interfacial interactions,significantly improving the mechanical properties of recycled WR.These disulfide interfacial interactions among the recycled WR tend to exchange,which dramatically increases the fractocohesive length and prevents stress concentration near the crack tips.When recycled WR is subjected to external stress,the loads are redistributed across a broad region of adjacent regions instead of being concentrated on a limited length scale,which resists crack propagation.This work effectively recycled WR,providing a strategy for solvent-free reaction-derived inverse vulcanization copolymers to improve the toughness of WR recycling.
