The biodegradation of polymeric biocomposites formed from epoxidized linseed oil and various types of fillers(pine needles,pine bark,grain mill waste,rapeseed cake)and a control sample without filler was studied durin...The biodegradation of polymeric biocomposites formed from epoxidized linseed oil and various types of fillers(pine needles,pine bark,grain mill waste,rapeseed cake)and a control sample without filler was studied during 180 days of exposure to two types of forest soil:deciduous and coniferous.The weight loss,morphological,and structural changes of polymer composites were noticed after 180 days of the soil burial test.The greatest weight loss of all tested samples was observed in coniferous forest soil(41.8%–63.2%),while in deciduous forest soil,it ranged between 37.7%and 42.3%.The most significant changes in the intensities of the signals evaluated by attenuated total reflectance infrared spectroscopy,as well as morphological changes determined by scanning electron microscopy,were assessed for polymer composite with rapeseed cake and specimen without filler in coniferous forest soil and are in a good agreement with weight loss results.Whereas significantly lower changes in weight loss,morphology,and structure of polymeric film with pine bark were noticed in both soils.It was suggested that fungi of Trichoderma,Penicillium,Talaromyces and Clonostachys genera are the possible soil microorganisms that degrade linseed oil-based cross-linked polymer composites.Moreover,the novel polymer composites have the potential to be an environmentally friendly alternative to petroleum-based mulching films.展开更多
With the industrialisation,industrial byproducts are produced in large quantities and create nuisance to natural habitats.The disposal of these wastes like fly ash,marble powder,construction and demolition(C&D)was...With the industrialisation,industrial byproducts are produced in large quantities and create nuisance to natural habitats.The disposal of these wastes like fly ash,marble powder,construction and demolition(C&D)waste,brick powder,agricultural wastes etc.has become the potential threat to the ecosystem and need some real solutions.The direct disposal of such wastes into open land or water bodies causes circumambient pollution.One of the potential solutions is to utilise these wastes in the construction industry on large scale as subgrade rehab or additive to cement based materials.In the present study,the compaction and strength characteristics of stabilised soil have been studied by using various waste materials i.e.lime,cement,plastic waste,industrial waste,fibre,mushroom waste,wet olive pomace etc.and reviewed.The addition of additives improved the engineering properties of soil significantly.展开更多
Abilities of agricultural waste materials (walnut shell-WS, rice husk-RH, and peanut hull-PH) were tested as adsorbents for the adsorption of Cr(Ⅵ) from aqueous solution. Batch adsorption experiments were carried out...Abilities of agricultural waste materials (walnut shell-WS, rice husk-RH, and peanut hull-PH) were tested as adsorbents for the adsorption of Cr(Ⅵ) from aqueous solution. Batch adsorption experiments were carried out to study the adsorption kinetics mechanism of Cr(Ⅵ) effect of adsorbent dosage, pH, contact time, and temperature. The best results are obtained at 15g/L adsorbent concentration, 60min contact time, 298K temperature, and 50mg/L adsorbate initial concentration at pH 2. The adsorption isotherms, using initial concentrations of Cr(Ⅵ) between 10 and 500mg/L for the Cr(Ⅵ) removal, show the maximum metal uptake capacities of adsorbent were 10.48, 6.71, and 8.54mg/g for WS, RH, and PH, respectively. And the adsorption data fitted well to the Langmuir adsorption isotherm for WS, RH, and PH with correlation coefficients of 0.9862, 0.9723, and 0.9714, respectively. Moreover, the FTIR analysis of WS, RH, and PH before and after adsorption of Cr(Ⅵ) suggested that Cr ions were combined to some functional groups of compounds contained in these materials.展开更多
A number of waste materials were studied on their application into asphalt mixtures. Materials tested were plastic waste as (soft) granular material,ceramic waste from electrical insulators,foundry sand and sintered g...A number of waste materials were studied on their application into asphalt mixtures. Materials tested were plastic waste as (soft) granular material,ceramic waste from electrical insulators,foundry sand and sintered granulate from burned household waste. Both plastic waste,crushed ceramics and large fractions of sintered household waste could be used as partial replacement for coarse aggregates. Foundry sand could partially replace natural sand in asphalt mixtures. The first step of the study was to find out if the waste materials could satisfy basic requirements and for some if their leaching behavior was acceptable. In the next phase mixtures were designed and mechanical tests were done on several mixtures with waste components to determine indirect tensile strength,stiffness,fatigue. In order to estimate the water sensitivity of some mixtures,retained indirect tension tests were done. The properties are reported and compared with each other and reference mixtures. From the research it becomes clear that it takes a lot of work to replace virgin materials in asphalt mixtures with waste materials.展开更多
Porous materials have promise as sound insulation, heat barrier, vibration attenuation, and catalysts. Most industrial solid wastes, such as tailings, coal gangue, and fly ash are rich in silicon. Additionally, a high...Porous materials have promise as sound insulation, heat barrier, vibration attenuation, and catalysts. Most industrial solid wastes, such as tailings, coal gangue, and fly ash are rich in silicon. Additionally, a high silicon content waste is a potential raw material for the syn- thesis of silicon-based, multi-porous materials such as zeolites, mesoporous silica, glass-ceramics, and geopolymer foams. Representative sil- icon-rich industrial solid wastes (SRISWs) are the focus of this mini review of the processing and application of porous silicon materials with respect to the physical and chemical properties of the SRISW. The transformation methods of preparing porous materials from SRISWs are summarized, and their research status in micro-, meso-, and macro-scale porous materials are described. Possible problems in the application of SRISWs and in the preparation of functional porous materials are analyzed, and their development prospects are discussed. This review should provide a typical reference for the recycling and use of industrial solid wastes to develop sustainable “green materials.”展开更多
In this work,the effects of pH value of waste water and initial concentration of phosphorus on dephosphorization materials were investigated.The materials were prepared by shaping,sintering and hydrothermal reshaping ...In this work,the effects of pH value of waste water and initial concentration of phosphorus on dephosphorization materials were investigated.The materials were prepared by shaping,sintering and hydrothermal reshaping oyster shell and silica micro-powder.Different concentrations of phosphorus-contained waste water were simulated with potassium dihydrogen phosphate solution,the effect of dephosphorization was tested with phosphomolybdenum blue spectrophotometer method,and the crystal phase and microstructure of materials were characterized by XRD and SEM methods. It was indicated that dephosphorization was completed in 6 h when the initial phosphorus concentration in waste water was lower than 15 mg/L, and the dephosphorization time prolonged as the increase of phosphorus concentration. It was observed that the pH value of waste water influenced dephosphorization significantly, and neutral subalkalic environment favored dephosphorization. When the pH value was 11, the efficiency of dephosphozation was the greatest. For waste water with an initial concentration of 20 mg/L, the dephosphozation rate is close to 100% in8 h.展开更多
Discarded train brake shoes mainly consist of steel-backed friction material. To be better reutilized, its essential features and its interaction in cement-based material need to be studied. Consequently, particle siz...Discarded train brake shoes mainly consist of steel-backed friction material. To be better reutilized, its essential features and its interaction in cement-based material need to be studied. Consequently, particle size analysis, SEM, IR and TGA were used to investigate two types of waste brake shoes, i e, mechanical grinding friction reclaimed material of waste brake-shoe(G-FRMWBS) and pyrolysis-friction reclaimed materials of waste brake-shoe(P-FRMWBS). The latter exhibited less organic content, larger range of particle size distribution and smaller medium particle diameter. Both types contained inorganic particles of spherical and irregular shapes, striped with steel fiber. Upon isometric substituting fine aggregates, G-FRMWBS lifted the strength of mortar effectively that was increased by 16.6% and 17.5% when the replacing rate was 5%; the value went up to 19.2% and 19.2% when the replacing rate was 10%. Moreover, inclusion of FRMWBS enhanced the chloride penetration resistance, and optimized the pore characteristic and ITZ(interfacial transition zone) as well.展开更多
The necessity and difficulties of waste building material utilization in comprehensive land consolidation are put forward by analyzing the source,quantity and harm of waste building materials.Combined with the practic...The necessity and difficulties of waste building material utilization in comprehensive land consolidation are put forward by analyzing the source,quantity and harm of waste building materials.Combined with the practice of Shanghai,the mechanism and pattern of waste building materials recycling are explored,in order to provide the reference for recycling of waste building materials and efficient promotion of land consolidation.展开更多
This study aimed to enhance the utilization of agricultural waste and identify the most suitable agricultural waste materials for tomato cultivation. It utilized a locally modified substrate labeled as CK, along with ...This study aimed to enhance the utilization of agricultural waste and identify the most suitable agricultural waste materials for tomato cultivation. It utilized a locally modified substrate labeled as CK, along with five different groups of agricultural waste materials, designated as T1 (organic fertilizer: loessial soil: straw in a ratio of 4:5:1), T2 (organic fertilizer: loessial soil: straw: grains in a ratio of 3:5:1:1), T3 (organic fertilizer: loessial soil: straw: grains in a ratio of 2:5:1:2), T4 (organic fertilizer:loessial soil:straw:grains in a ratio of 1:5:1:3), and T5 ( loessial soil:straw:grains in a ratio of 5:1:4), the AquaCrop model was employed to validate soil water content and tomato growth and yield under these treatments. Furthermore, a multi-objective genetic algorithm was employed to determine the optimal agricultural waste materials that would ensure maximum tomato yield, water use efficiency (WUE), partial factor productivity of fertilizer (PFP) and sugar-acid ratio. The results indicated that the AquaCrop model reasonably simulated volumetric soil water content, tomato canopy cover, and biomass, with root mean square error (RMSE) ranges of 20.0-69.4 mm, 15.2%-25.1%, and 1.093-3.469 t/hm2, respectively. The CK group exhibited an R-squared (R2) value of 0.63 for volumetric soil water contents, while the ratio scenarios showed R2 values exceeding 0.80. The multi-objective genetic optimization algorithm identified T5 as the optimal ratio scenario, resulting in maximum tomato yield, WUE, PFP, and quality. This study offers a theoretical foundation for the efficient utilization of agricultural wastes and the production of high-quality fruits and vegetables.展开更多
Rhenium is a very scarce element, occurring in the Earth's crust mainly carried by molybdenite (MoS2). Due to a very low availability comparative to actual industrial demand, rhenium is nowadays one of the most ex...Rhenium is a very scarce element, occurring in the Earth's crust mainly carried by molybdenite (MoS2). Due to a very low availability comparative to actual industrial demand, rhenium is nowadays one of the most expensive mineral commodities and an increased interest is focused on ex- ploring residues resulting from a long-term mining, particularly of sulphide ore deposits. It is therefore noteworthy to assign the presence of rhenium (in a concentration up to 3 ppm) in the waste materials from the old sulphur factory at the abandoned mine of Sao Domingos (Iberian Pyrite Belt, Southeast Portugal), exploited since the Roman occupation of Iberia. Aiming at a potential sustainable recovery of rhenium as a by-product, X-ray near-edge absorption spectroscopy (XANES) was applied to clarify the Re-binding and mode of occurrence by comparing Re L3-edge XANES spectra obtained from mine waste samples (previously fully characterized by X-ray laboratory techniques) with similar spectra collected from Re-rich molybdenites (Mo1-xRexS2) and from Re-O model compounds configuring various valences and coordination environments of rhenium ions. Obtained results are commented, ruling out a possible Re-S binding and rather conforming with the binding of rhenium to oxygen in the analysed mine waste materials.展开更多
With the adjustment of urban industrial structure,a large number of ruins have emerged in cities,and the waste materials left by these ruins not only occupy urban space resources,but also seriously damage the ecologic...With the adjustment of urban industrial structure,a large number of ruins have emerged in cities,and the waste materials left by these ruins not only occupy urban space resources,but also seriously damage the ecological environment.How to identify the value of waste materials through landscape thinking and how to rationally reuse these waste materials through landscape methods is the focus of this paper.展开更多
Autoclaved aerated concrete(AAC)has become more attractive due to its excellent and environmental-friendly properties in building construction.AAC is relatively lightweight,possesses lower thermal conductivity,higher ...Autoclaved aerated concrete(AAC)has become more attractive due to its excellent and environmental-friendly properties in building construction.AAC is relatively lightweight,possesses lower thermal conductivity,higher heat resistance,lower shrinkage,and fasten construction than normal concrete.AAC is a combination of silica sand,cement,gypsum,lime,water,and an expansion agent.To improve its physical and mechanical properties and reduce its production cost,tremendous innovations where waste materials were utilized as partial replacement of AAC materials were done.This paper is intended to present the literature on the utilization of waste materials as a means of a partial replacement in AAC materials to enhance its physical and mechanical properties and thermal performance.The physical properties such as microstructure and mechanical properties such as density,compressive strength,water absorption are presented to classify the investigation that has been done in such innovations.Apart from that,the discussion on innovations to improve its thermal performance was also presented.Based on the review,an increase of AAC application causes much waste at construction sites and recycling concrete waste powder into wall concrete;particularly,an AAC was not frequently practiced in construction.展开更多
According to the principle of belt seeding establishment of adhesive bonded fabric,applied indexes of belt seeding establishment effect were studied using carrier combination of several kinds of waste meterials under...According to the principle of belt seeding establishment of adhesive bonded fabric,applied indexes of belt seeding establishment effect were studied using carrier combination of several kinds of waste meterials under soil cover.The results showed that the effect depended on the coordinated characteristics of carrier combination from turfgrass and waste materials.It was testified that production of belt seeding was feasible using a certain kind of waste material carrier under given conditions.The study provided a scientific basis for applying evvironmental engineering to belt seeding establishment of waste materials and developing nwe industry of environmental protection.展开更多
Globally,fossil fuel dependence has created several environmental challenges and climate change.Hence,creating other alternative renewable and ecologically friendly bio-energy sources is necessary.Lignocellulosic biom...Globally,fossil fuel dependence has created several environmental challenges and climate change.Hence,creating other alternative renewable and ecologically friendly bio-energy sources is necessary.Lignocellulosic biomass has gained significant attention recently as a renewable material for biofuel production.The large amounts of plantain and banana plant parts wasted after harvesting,as well as the peels generated daily by the fruit market and industries,demonstrate the potential of bioenergy resources.This review briefly assesses plantain and banana plant biomass(PBB)generated in the developing,developed,and underdeveloped countries,the consumable parts,and feasible products yield.It emphasized the advantages and disadvantages of the commonly adopted treatment technologies of composting,incineration,and landfilling.Further,the utilization of PBB as catalysts in biodiesel synthesis was briefly highlighted.To optimize recovery of biofuel,different integration routes of pyrolysis,anaerobic digestion,fermentation,hydrothermal carbonization,hydrothermal liquefaction,and hydrothermal gasification for the valorization of the PBB were proposed.The complex compounds present in the PBB(hemicellulose,cellulose,and lignin)can be converted into valuable bio-products such as methane gas and bio-ethanol for bioenergy,and nutrients to promote bioactive ingredients.The investigation of the viability and innovation potential of the integrated routes’technology is necessary to improve the circular bio-economy and the recovery of biofuels from biomass waste,particularly PBB.展开更多
Substantial environmental and economic benefits can be achieved by recycling used lithium-ion batteries. Hydrometallurgy is often employed to recover waste LiNi_(x)Co_(y)Mn_(z)O_(2) cathode materials. As Ni, Co and Mn...Substantial environmental and economic benefits can be achieved by recycling used lithium-ion batteries. Hydrometallurgy is often employed to recover waste LiNi_(x)Co_(y)Mn_(z)O_(2) cathode materials. As Ni, Co and Mn are transition metals, they exhibit similar properties;therefore, separating them is difficult. Thus, most researchers have focused on leaching processes, while minimal attention has been devoted to the separation of valuable metals from waste LiNi_(x)Co_(y)Mn_(z)O_(2) cathode materials. Herein, we propose an environment-friendly, gentle process involving the usage of pyrometallurgy and hydrometallurgy to gradually leach valuable metals and effectively separate them. Interestingly, Li is recovered through a reduction roasting and water leaching process using natural graphite powder, Ni and Co are recovered through ammonia leaching and extraction processes and Mn is recovered through acid leaching and evaporation–crystallization processes. Results show that ~87% Li, 97.01% Co, 97.08% Ni and 99% Mn can be leached using water, ammonia and acid leaching processes. The result obtained using the response surface methodology shows that the concentration of (NH4)2SO3 is a notable factor affecting the leaching of transition metals. Under optimal conditions, ~97.01% Co, 97.08% Ni and 0.64% Mn can be leached out. The decomposition of LiNi_(x)Co_(y)Mn_(z)O_(2) is a two-step process. This study provides valuable insights to develop an environment-friendly, gentle leaching process for efficiently recycling valuable metals, which is vital for the lithium-ion battery recycling industry.展开更多
Coarse and fine aggregate constitutes an average of approximately 55% to 80% of the total volume of concrete materials.Concrete remains the most commonly-used building material worldwide.As a result,the massive use of...Coarse and fine aggregate constitutes an average of approximately 55% to 80% of the total volume of concrete materials.Concrete remains the most commonly-used building material worldwide.As a result,the massive use of aggregate will have a direct impact on the earth′s natural resources if an appropriate replacement material is not found,violating the spirit of sustainable development.This study makes a preliminary examination of using coarse and fine aggregate produced from discarded construction materials in concrete.Results indicate that the compressive strength of densified mixture concrete at 28 days can reach 56.88 MPa(recycled materials used as coarse aggregate,and natural sand used as fine aggregate)and 53.33 MPa(recycled materials used as both coarse and fine aggregate).While this type of material is not yet fully understood,further research into this area should enable feasible applications in concrete.However,unsuitable mixtures have serious impact on the durability and overall economy of concrete.Pending further research on suitable mixture designs,a complete application of recycled aggregate in concrete can be expected.展开更多
In this experimental study,the impact of Portland cement replacement by ground granulated blast furnace slag(GGBFS)and micronized rubber powder(MRP)on the compressive,flexural,tensile strengths,and rapid chloride migr...In this experimental study,the impact of Portland cement replacement by ground granulated blast furnace slag(GGBFS)and micronized rubber powder(MRP)on the compressive,flexural,tensile strengths,and rapid chloride migration test(RCMT)of concrete were assessed.In this study,samples with different binder content and water to binder ratios,including the MRP with the substitution levels of 0%,2.5%and 5%,and the GGBFS with the substitution ratios of 0%,20%and 40%by weight of Portland cement were made.According to the results,in the samples containing slag and rubber powder in the early ages,on average,a 12.2%decrease in the mechanical characteristics of concrete was observed,nonetheless with raising the age of the samples,the impact of slag on reducing the porosity of concrete lowered the negative impact of rubber powder.Regarding durability characteristics,the RCMT results of the samples were enhanced by using rubber powder because of its insulation impact.Moreover,adding slag into the MRP-included mixtures results in a 23%reduction in the migration rate of the chloride ion averagely.At last,four mathematical statements were derived for the mechanical and durability of concrete containing the MRP and GGBFS utilizing the genetic programming method.展开更多
The CTB Water Wall project is a maximal product life cycle utilization concept study by members of the space architecture design community.Its function is to demonstrate a human space activity Cargo Transport Bag(CTB)...The CTB Water Wall project is a maximal product life cycle utilization concept study by members of the space architecture design community.Its function is to demonstrate a human space activity Cargo Transport Bag(CTB)that becomes a primary water recycling membrane element after delivery of cargo,and then a permanent architectural building block for sustainable space habitation after its use in water treatment is complete.As such,it is intended as an experiment in radical life cycle product optimization in an extremely mass-constrained application environment(human space operations).It also introduces some fundamentally interesting concepts in architectural use of waste materials in extreme environments.Finally,it is in some ways a simple,tactile and visual demonstration of how far sustainable product design can be taken,if the motivation and technical justification are present.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
Aiming to the low-grade rhodium-containing waste materials, a new process was proposed to enrich and activate rhodium by smelting using iron oxide as a trapping agent and activator. A rhodium concentrate was obtained ...Aiming to the low-grade rhodium-containing waste materials, a new process was proposed to enrich and activate rhodium by smelting using iron oxide as a trapping agent and activator. A rhodium concentrate was obtained by the separation of base metals and precious metals. The concentrate was reacted with dilute aqua regia to obtain rhodium solution. The factors influencing the enrichment and activation effects were discussed in this paper. The results showed that the dissolution rate is greater than 99% under the optimum conditions. In this process, the activation of rhodium was finished in the enrichment process. The iron oxide is both a trapping agent and activator, which simplifies the process and reduce the cost.展开更多
文摘The biodegradation of polymeric biocomposites formed from epoxidized linseed oil and various types of fillers(pine needles,pine bark,grain mill waste,rapeseed cake)and a control sample without filler was studied during 180 days of exposure to two types of forest soil:deciduous and coniferous.The weight loss,morphological,and structural changes of polymer composites were noticed after 180 days of the soil burial test.The greatest weight loss of all tested samples was observed in coniferous forest soil(41.8%–63.2%),while in deciduous forest soil,it ranged between 37.7%and 42.3%.The most significant changes in the intensities of the signals evaluated by attenuated total reflectance infrared spectroscopy,as well as morphological changes determined by scanning electron microscopy,were assessed for polymer composite with rapeseed cake and specimen without filler in coniferous forest soil and are in a good agreement with weight loss results.Whereas significantly lower changes in weight loss,morphology,and structure of polymeric film with pine bark were noticed in both soils.It was suggested that fungi of Trichoderma,Penicillium,Talaromyces and Clonostachys genera are the possible soil microorganisms that degrade linseed oil-based cross-linked polymer composites.Moreover,the novel polymer composites have the potential to be an environmentally friendly alternative to petroleum-based mulching films.
文摘With the industrialisation,industrial byproducts are produced in large quantities and create nuisance to natural habitats.The disposal of these wastes like fly ash,marble powder,construction and demolition(C&D)waste,brick powder,agricultural wastes etc.has become the potential threat to the ecosystem and need some real solutions.The direct disposal of such wastes into open land or water bodies causes circumambient pollution.One of the potential solutions is to utilise these wastes in the construction industry on large scale as subgrade rehab or additive to cement based materials.In the present study,the compaction and strength characteristics of stabilised soil have been studied by using various waste materials i.e.lime,cement,plastic waste,industrial waste,fibre,mushroom waste,wet olive pomace etc.and reviewed.The addition of additives improved the engineering properties of soil significantly.
基金National Natural Science Foundations of China(No.40771185,No.51004053)Li Shang-da Scientific Research Foundation of Jimei University,China(No.ZC2011015)
文摘Abilities of agricultural waste materials (walnut shell-WS, rice husk-RH, and peanut hull-PH) were tested as adsorbents for the adsorption of Cr(Ⅵ) from aqueous solution. Batch adsorption experiments were carried out to study the adsorption kinetics mechanism of Cr(Ⅵ) effect of adsorbent dosage, pH, contact time, and temperature. The best results are obtained at 15g/L adsorbent concentration, 60min contact time, 298K temperature, and 50mg/L adsorbate initial concentration at pH 2. The adsorption isotherms, using initial concentrations of Cr(Ⅵ) between 10 and 500mg/L for the Cr(Ⅵ) removal, show the maximum metal uptake capacities of adsorbent were 10.48, 6.71, and 8.54mg/g for WS, RH, and PH, respectively. And the adsorption data fitted well to the Langmuir adsorption isotherm for WS, RH, and PH with correlation coefficients of 0.9862, 0.9723, and 0.9714, respectively. Moreover, the FTIR analysis of WS, RH, and PH before and after adsorption of Cr(Ⅵ) suggested that Cr ions were combined to some functional groups of compounds contained in these materials.
文摘A number of waste materials were studied on their application into asphalt mixtures. Materials tested were plastic waste as (soft) granular material,ceramic waste from electrical insulators,foundry sand and sintered granulate from burned household waste. Both plastic waste,crushed ceramics and large fractions of sintered household waste could be used as partial replacement for coarse aggregates. Foundry sand could partially replace natural sand in asphalt mixtures. The first step of the study was to find out if the waste materials could satisfy basic requirements and for some if their leaching behavior was acceptable. In the next phase mixtures were designed and mechanical tests were done on several mixtures with waste components to determine indirect tensile strength,stiffness,fatigue. In order to estimate the water sensitivity of some mixtures,retained indirect tension tests were done. The properties are reported and compared with each other and reference mixtures. From the research it becomes clear that it takes a lot of work to replace virgin materials in asphalt mixtures with waste materials.
基金National Natural Science Foundation of China(No.51774331)Funds for Nationsl&Local Joint Engineering Research Center of Mineral Salt Deep Utilization(No.SF202103).
文摘Porous materials have promise as sound insulation, heat barrier, vibration attenuation, and catalysts. Most industrial solid wastes, such as tailings, coal gangue, and fly ash are rich in silicon. Additionally, a high silicon content waste is a potential raw material for the syn- thesis of silicon-based, multi-porous materials such as zeolites, mesoporous silica, glass-ceramics, and geopolymer foams. Representative sil- icon-rich industrial solid wastes (SRISWs) are the focus of this mini review of the processing and application of porous silicon materials with respect to the physical and chemical properties of the SRISW. The transformation methods of preparing porous materials from SRISWs are summarized, and their research status in micro-, meso-, and macro-scale porous materials are described. Possible problems in the application of SRISWs and in the preparation of functional porous materials are analyzed, and their development prospects are discussed. This review should provide a typical reference for the recycling and use of industrial solid wastes to develop sustainable “green materials.”
基金Supported by Fujian Science and Technology Administration (2004I003 and 20060037)
文摘In this work,the effects of pH value of waste water and initial concentration of phosphorus on dephosphorization materials were investigated.The materials were prepared by shaping,sintering and hydrothermal reshaping oyster shell and silica micro-powder.Different concentrations of phosphorus-contained waste water were simulated with potassium dihydrogen phosphate solution,the effect of dephosphorization was tested with phosphomolybdenum blue spectrophotometer method,and the crystal phase and microstructure of materials were characterized by XRD and SEM methods. It was indicated that dephosphorization was completed in 6 h when the initial phosphorus concentration in waste water was lower than 15 mg/L, and the dephosphorization time prolonged as the increase of phosphorus concentration. It was observed that the pH value of waste water influenced dephosphorization significantly, and neutral subalkalic environment favored dephosphorization. When the pH value was 11, the efficiency of dephosphozation was the greatest. For waste water with an initial concentration of 20 mg/L, the dephosphozation rate is close to 100% in8 h.
基金Funded by National Natural Science Foundation of China(Nos.51408380,No.51478278)Science and Technology Plan of Hebei Province,China(No.14273805D)+1 种基金He Bei Education Department(No.QN2016156)the Young Top Talent Science Research Project of Colleges and Universities in He Bei Province(No.BJ2014053)
文摘Discarded train brake shoes mainly consist of steel-backed friction material. To be better reutilized, its essential features and its interaction in cement-based material need to be studied. Consequently, particle size analysis, SEM, IR and TGA were used to investigate two types of waste brake shoes, i e, mechanical grinding friction reclaimed material of waste brake-shoe(G-FRMWBS) and pyrolysis-friction reclaimed materials of waste brake-shoe(P-FRMWBS). The latter exhibited less organic content, larger range of particle size distribution and smaller medium particle diameter. Both types contained inorganic particles of spherical and irregular shapes, striped with steel fiber. Upon isometric substituting fine aggregates, G-FRMWBS lifted the strength of mortar effectively that was increased by 16.6% and 17.5% when the replacing rate was 5%; the value went up to 19.2% and 19.2% when the replacing rate was 10%. Moreover, inclusion of FRMWBS enhanced the chloride penetration resistance, and optimized the pore characteristic and ITZ(interfacial transition zone) as well.
基金Sponsored by Social Development Project of “Science and Technology Innovation Action Plan” of Shanghai Science and Technology Commission in 2019 (19DZ1203400)。
文摘The necessity and difficulties of waste building material utilization in comprehensive land consolidation are put forward by analyzing the source,quantity and harm of waste building materials.Combined with the practice of Shanghai,the mechanism and pattern of waste building materials recycling are explored,in order to provide the reference for recycling of waste building materials and efficient promotion of land consolidation.
基金supported by the National Natural Science Foundation of China(Grant No.52379042)Key R&D plan of Gansu Province(Grant No.23YFFA0019)Gansu Province East-West Cooperation Project(Grant No.23CXNA0025).
文摘This study aimed to enhance the utilization of agricultural waste and identify the most suitable agricultural waste materials for tomato cultivation. It utilized a locally modified substrate labeled as CK, along with five different groups of agricultural waste materials, designated as T1 (organic fertilizer: loessial soil: straw in a ratio of 4:5:1), T2 (organic fertilizer: loessial soil: straw: grains in a ratio of 3:5:1:1), T3 (organic fertilizer: loessial soil: straw: grains in a ratio of 2:5:1:2), T4 (organic fertilizer:loessial soil:straw:grains in a ratio of 1:5:1:3), and T5 ( loessial soil:straw:grains in a ratio of 5:1:4), the AquaCrop model was employed to validate soil water content and tomato growth and yield under these treatments. Furthermore, a multi-objective genetic algorithm was employed to determine the optimal agricultural waste materials that would ensure maximum tomato yield, water use efficiency (WUE), partial factor productivity of fertilizer (PFP) and sugar-acid ratio. The results indicated that the AquaCrop model reasonably simulated volumetric soil water content, tomato canopy cover, and biomass, with root mean square error (RMSE) ranges of 20.0-69.4 mm, 15.2%-25.1%, and 1.093-3.469 t/hm2, respectively. The CK group exhibited an R-squared (R2) value of 0.63 for volumetric soil water contents, while the ratio scenarios showed R2 values exceeding 0.80. The multi-objective genetic optimization algorithm identified T5 as the optimal ratio scenario, resulting in maximum tomato yield, WUE, PFP, and quality. This study offers a theoretical foundation for the efficient utilization of agricultural wastes and the production of high-quality fruits and vegetables.
基金the project MinReMol(Ref.EXPL/AAG-REC/0978/2012),financed by FEDER Funds through the Operational Program on Competitive Factors(COMPETE:FCOMP-01-0124-FEDER-027516)by national funds through the Portuguese Foundation for Science and Technology(FCT-MCTES)support of FCT-MCTES through the Strategic Project LA25-2011-2012(ref.PEst-C/CTM/LA0025/2011).
文摘Rhenium is a very scarce element, occurring in the Earth's crust mainly carried by molybdenite (MoS2). Due to a very low availability comparative to actual industrial demand, rhenium is nowadays one of the most expensive mineral commodities and an increased interest is focused on ex- ploring residues resulting from a long-term mining, particularly of sulphide ore deposits. It is therefore noteworthy to assign the presence of rhenium (in a concentration up to 3 ppm) in the waste materials from the old sulphur factory at the abandoned mine of Sao Domingos (Iberian Pyrite Belt, Southeast Portugal), exploited since the Roman occupation of Iberia. Aiming at a potential sustainable recovery of rhenium as a by-product, X-ray near-edge absorption spectroscopy (XANES) was applied to clarify the Re-binding and mode of occurrence by comparing Re L3-edge XANES spectra obtained from mine waste samples (previously fully characterized by X-ray laboratory techniques) with similar spectra collected from Re-rich molybdenites (Mo1-xRexS2) and from Re-O model compounds configuring various valences and coordination environments of rhenium ions. Obtained results are commented, ruling out a possible Re-S binding and rather conforming with the binding of rhenium to oxygen in the analysed mine waste materials.
文摘With the adjustment of urban industrial structure,a large number of ruins have emerged in cities,and the waste materials left by these ruins not only occupy urban space resources,but also seriously damage the ecological environment.How to identify the value of waste materials through landscape thinking and how to rationally reuse these waste materials through landscape methods is the focus of this paper.
基金The financial supports are from the Ministry of Education Malaysia under the Fundamental Research Grant Scheme(FRGS/1/2018/TK06/UKM/02/1).
文摘Autoclaved aerated concrete(AAC)has become more attractive due to its excellent and environmental-friendly properties in building construction.AAC is relatively lightweight,possesses lower thermal conductivity,higher heat resistance,lower shrinkage,and fasten construction than normal concrete.AAC is a combination of silica sand,cement,gypsum,lime,water,and an expansion agent.To improve its physical and mechanical properties and reduce its production cost,tremendous innovations where waste materials were utilized as partial replacement of AAC materials were done.This paper is intended to present the literature on the utilization of waste materials as a means of a partial replacement in AAC materials to enhance its physical and mechanical properties and thermal performance.The physical properties such as microstructure and mechanical properties such as density,compressive strength,water absorption are presented to classify the investigation that has been done in such innovations.Apart from that,the discussion on innovations to improve its thermal performance was also presented.Based on the review,an increase of AAC application causes much waste at construction sites and recycling concrete waste powder into wall concrete;particularly,an AAC was not frequently practiced in construction.
基金supported by National Science Foundation of China (5 98780 33) Young Science Foundation of Tianjin- 2 1Centuries(97370 5 111)
文摘According to the principle of belt seeding establishment of adhesive bonded fabric,applied indexes of belt seeding establishment effect were studied using carrier combination of several kinds of waste meterials under soil cover.The results showed that the effect depended on the coordinated characteristics of carrier combination from turfgrass and waste materials.It was testified that production of belt seeding was feasible using a certain kind of waste material carrier under given conditions.The study provided a scientific basis for applying evvironmental engineering to belt seeding establishment of waste materials and developing nwe industry of environmental protection.
基金This work was supported by the Start-Up Funding for Research of Nanchang Institute of Science and Technology(NGRCZX-22-03)School of Environment and Civil Engineering,Nanchang,Jiangxi,China.
文摘Globally,fossil fuel dependence has created several environmental challenges and climate change.Hence,creating other alternative renewable and ecologically friendly bio-energy sources is necessary.Lignocellulosic biomass has gained significant attention recently as a renewable material for biofuel production.The large amounts of plantain and banana plant parts wasted after harvesting,as well as the peels generated daily by the fruit market and industries,demonstrate the potential of bioenergy resources.This review briefly assesses plantain and banana plant biomass(PBB)generated in the developing,developed,and underdeveloped countries,the consumable parts,and feasible products yield.It emphasized the advantages and disadvantages of the commonly adopted treatment technologies of composting,incineration,and landfilling.Further,the utilization of PBB as catalysts in biodiesel synthesis was briefly highlighted.To optimize recovery of biofuel,different integration routes of pyrolysis,anaerobic digestion,fermentation,hydrothermal carbonization,hydrothermal liquefaction,and hydrothermal gasification for the valorization of the PBB were proposed.The complex compounds present in the PBB(hemicellulose,cellulose,and lignin)can be converted into valuable bio-products such as methane gas and bio-ethanol for bioenergy,and nutrients to promote bioactive ingredients.The investigation of the viability and innovation potential of the integrated routes’technology is necessary to improve the circular bio-economy and the recovery of biofuels from biomass waste,particularly PBB.
基金supported by supported by Yunnan Major Scientific and Technological Projects(China)(No.202202AG050003).
文摘Substantial environmental and economic benefits can be achieved by recycling used lithium-ion batteries. Hydrometallurgy is often employed to recover waste LiNi_(x)Co_(y)Mn_(z)O_(2) cathode materials. As Ni, Co and Mn are transition metals, they exhibit similar properties;therefore, separating them is difficult. Thus, most researchers have focused on leaching processes, while minimal attention has been devoted to the separation of valuable metals from waste LiNi_(x)Co_(y)Mn_(z)O_(2) cathode materials. Herein, we propose an environment-friendly, gentle process involving the usage of pyrometallurgy and hydrometallurgy to gradually leach valuable metals and effectively separate them. Interestingly, Li is recovered through a reduction roasting and water leaching process using natural graphite powder, Ni and Co are recovered through ammonia leaching and extraction processes and Mn is recovered through acid leaching and evaporation–crystallization processes. Results show that ~87% Li, 97.01% Co, 97.08% Ni and 99% Mn can be leached using water, ammonia and acid leaching processes. The result obtained using the response surface methodology shows that the concentration of (NH4)2SO3 is a notable factor affecting the leaching of transition metals. Under optimal conditions, ~97.01% Co, 97.08% Ni and 0.64% Mn can be leached out. The decomposition of LiNi_(x)Co_(y)Mn_(z)O_(2) is a two-step process. This study provides valuable insights to develop an environment-friendly, gentle leaching process for efficiently recycling valuable metals, which is vital for the lithium-ion battery recycling industry.
文摘Coarse and fine aggregate constitutes an average of approximately 55% to 80% of the total volume of concrete materials.Concrete remains the most commonly-used building material worldwide.As a result,the massive use of aggregate will have a direct impact on the earth′s natural resources if an appropriate replacement material is not found,violating the spirit of sustainable development.This study makes a preliminary examination of using coarse and fine aggregate produced from discarded construction materials in concrete.Results indicate that the compressive strength of densified mixture concrete at 28 days can reach 56.88 MPa(recycled materials used as coarse aggregate,and natural sand used as fine aggregate)and 53.33 MPa(recycled materials used as both coarse and fine aggregate).While this type of material is not yet fully understood,further research into this area should enable feasible applications in concrete.However,unsuitable mixtures have serious impact on the durability and overall economy of concrete.Pending further research on suitable mixture designs,a complete application of recycled aggregate in concrete can be expected.
文摘In this experimental study,the impact of Portland cement replacement by ground granulated blast furnace slag(GGBFS)and micronized rubber powder(MRP)on the compressive,flexural,tensile strengths,and rapid chloride migration test(RCMT)of concrete were assessed.In this study,samples with different binder content and water to binder ratios,including the MRP with the substitution levels of 0%,2.5%and 5%,and the GGBFS with the substitution ratios of 0%,20%and 40%by weight of Portland cement were made.According to the results,in the samples containing slag and rubber powder in the early ages,on average,a 12.2%decrease in the mechanical characteristics of concrete was observed,nonetheless with raising the age of the samples,the impact of slag on reducing the porosity of concrete lowered the negative impact of rubber powder.Regarding durability characteristics,the RCMT results of the samples were enhanced by using rubber powder because of its insulation impact.Moreover,adding slag into the MRP-included mixtures results in a 23%reduction in the migration rate of the chloride ion averagely.At last,four mathematical statements were derived for the mechanical and durability of concrete containing the MRP and GGBFS utilizing the genetic programming method.
文摘The CTB Water Wall project is a maximal product life cycle utilization concept study by members of the space architecture design community.Its function is to demonstrate a human space activity Cargo Transport Bag(CTB)that becomes a primary water recycling membrane element after delivery of cargo,and then a permanent architectural building block for sustainable space habitation after its use in water treatment is complete.As such,it is intended as an experiment in radical life cycle product optimization in an extremely mass-constrained application environment(human space operations).It also introduces some fundamentally interesting concepts in architectural use of waste materials in extreme environments.Finally,it is in some ways a simple,tactile and visual demonstration of how far sustainable product design can be taken,if the motivation and technical justification are present.
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The Nationa lBasic Research Program(973Plan)of China(2010CB735501)
文摘Aiming to the low-grade rhodium-containing waste materials, a new process was proposed to enrich and activate rhodium by smelting using iron oxide as a trapping agent and activator. A rhodium concentrate was obtained by the separation of base metals and precious metals. The concentrate was reacted with dilute aqua regia to obtain rhodium solution. The factors influencing the enrichment and activation effects were discussed in this paper. The results showed that the dissolution rate is greater than 99% under the optimum conditions. In this process, the activation of rhodium was finished in the enrichment process. The iron oxide is both a trapping agent and activator, which simplifies the process and reduce the cost.