A flower-like BiOBr photocatalyst(CS/BiOBr)was prepared by using the carbon material derived from corn straw(CS)as the carrier.The prepared composites were characterized by X-ray diffraction(XRD),Fourier transform inf...A flower-like BiOBr photocatalyst(CS/BiOBr)was prepared by using the carbon material derived from corn straw(CS)as the carrier.The prepared composites were characterized by X-ray diffraction(XRD),Fourier transform infrared(FIIR)spectra,scanning electron microscope(SEM),X-ray photoelectron spectra(XPS),and UV-Vis diffuse reflectance spectra(UV-Vis DRS).The SEM analyses indicate that the introduction of CS promotes the formation of a unique flower-like structure in BiOBr,which not only optimizes the efficiency of light capture but also increases the specific surface area of BiOBr.The bandgap of the composite was narrower compared with the pure BiOBr.The CS/BiOBr composites exhibited higher photocatalytic activity than pure CS and BiOBr under visible light irradiation,and a higher first-order reaction rate constant(k)of 0.0437 min-1 than BiOBr(0.0146 min^(-1)),and exhibited excellent stability and reusability during the cyclic run.The enhanced photocatalytic activity is attributed to the efficient separation of photoinduced electrons and holes.Superoxide radicals and holes were the major active species.展开更多
Jerada coal mining generates extensive coal mine waste rock(CMWR)piles rich in valuable minerals,posing environmental challenges and economic opportunities.This study examines reprocessing feasibility through 3D geome...Jerada coal mining generates extensive coal mine waste rock(CMWR)piles rich in valuable minerals,posing environmental challenges and economic opportunities.This study examines reprocessing feasibility through 3D geometallurgical characterization.Sampling used down the hole hammer drilling technique(DTH)and drone surveys for topographical precision.Over 620 samples from(T01,T02,T08)underwent comprehensive analyses including particle size distribution,x-ray fluorescence(XRF),total sulfur/carbon analysis(S/C),and inductively coupled plasma mass spectrometry(ICP-MS)for physical-chemical characterization.Mineralogical aspects were explored via optical microscopy(OM),X-ray diffraction(XRD),scanning electron microscopy(SEM),electron probe microanalysis(EPMA),and laser ablation inductively coupled plasma mass spectrometry(LA-ICP-MS).Quantitative mineral evaluation by scanning electron microscope(QEMSCAN)provided mineral insights.Chemical data was used in a 3D block model to quantify residual coal.Results for the three examined CMWR piles(T01,T02,and T08)showed varying D80 from 160 to 300μm,notable carbon content averaged 12.5 wt%(T01),16 wt%(T02),and 8.5 wt%(T08).Sulfur presence exceeded 1 wt%in T08,and potential environmental concerns due to iron sulfides.Anthracite liberation was below 30 wt%.3D modeling estimated a total volume of 7 Mm3,mainly from T08,equaling 11.2 Mt.With its high carbon content and substantial tonnages,re-exploitation or alternative applications could minimize these CMWR piles environmental impact.展开更多
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
High-steep waste dumps in open-pit mines frequently demonstrate complex particle-size distributions and fractal characteristics along their slopes,which have a significant impact on slope stability.This study takes th...High-steep waste dumps in open-pit mines frequently demonstrate complex particle-size distributions and fractal characteristics along their slopes,which have a significant impact on slope stability.This study takes the Dasuji South waste dump in Inner Mongolia as a case to quantify the fractal dimensions of soil-rock mixtures at various slope heights,and to clarify how these fractal properties govern shear strength and deformation behavior under overlying stress,thereby affecting the overall stability of the waste dump slope.Field sampling and laboratory tests were conducted to determine the particle-size composition and fractal dimensions while direct shear tests were conducted and revealed that lower fractal dimensions indicating coarser particle assemblages significantly enhance shear resistance.Complementary PFC_(2)D discrete element simulations demonstrate that slopes composed of lower-fractaldimension materials deform less and contain localized deformation zones,whereas higher-fractal-dimension slopes experience more extensive displacement and a heightened risk of landslides.These findings refine our understanding of the relationship between fractal grain-size distribution and slope stability,providing a robust theoretical basis for improved stability assessment and optimized support strategies in deep open-pit mining waste dumps,and ultimately aiding in more effective disaster prevention within geotechnical engineering.展开更多
Driven by rapid technological advancements and economic growth,mineral extraction and metal refining have increased dramatically,generating huge volumes of tailings and mine waste(TMWs).Investigating the morphological...Driven by rapid technological advancements and economic growth,mineral extraction and metal refining have increased dramatically,generating huge volumes of tailings and mine waste(TMWs).Investigating the morphological fractions of heavy metals and metalloids(HMMs)in TMWs is key to evaluating their leaching potential into the environment;however,traditional experiments are time-consuming and labor-intensive.In this study,10 machine learning(ML)algorithms were used and compared for rapidly predicting the morphological fractions of HMMs in TMWs.A dataset comprising 2376 data points was used,with mineral composition,elemental properties,and total concentration used as inputs and concentration of morphological fraction used as output.After grid search optimization,the extra tree model performed the best,achieving coefficient of determination(R2)of 0.946 and 0.942 on the validation and test sets,respectively.Electronegativity was found to have the greatest impact on the morphological fraction.The models’performance was enhanced by applying an ensemble method to the top three optimal ML models,including gradient boosting decision tree,extra trees and categorical boosting.Overall,the proposed framework can accurately predict the concentrations of different morphological fractions of HMMs in TMWs.This approach can minimize detection time,aid in the safe management and recovery of TMWs.展开更多
Safety berms(also called safety bunds or windrows),widely employed in surface mining and quarry operations,are typically designed based on rules of thumb.Despite having been used by the industry for more than half a c...Safety berms(also called safety bunds or windrows),widely employed in surface mining and quarry operations,are typically designed based on rules of thumb.Despite having been used by the industry for more than half a century and accidents happening regularly,their behaviour is still poorly understood.This paper challenges existing practices through a comprehensive investigation combining full-scale experiments and advanced numerical modelling.Focusing on a Volvo A45G articulated dump truck(ADT)and a CAT 773B rigid dump truck(RDT),collision scenarios under various approach conditions and different safety berm geometries and materials are rigorously examined.The calibrated numerical model is used to assess the energy absorption capacity of safety berms with different geometry and to predict a critical velocity for a specific scenario.Back analysis of an actual fatal accident indicated that an ADT adhering to the speed limit could not be stopped by the safety berm designed under current guidelines.The study highlights the importance of considering the entire geometry and the mass and volume of the material used to build the safety berm alongside the speed and approach conditions of the machinery.The findings of the study enable operators to set speed limits based on specific berm geometries or adapt safety berm designs to match speed constraints for specific machinery.This will reduce the risk of fatal accidents and improve haul road safety.展开更多
Coal is an essential component of global energy;however,the processes of coal mining and utilization produce significant amounts of coal mine goafs,accompanied by coal-based solid wastes and emitted CO_(2),resulting i...Coal is an essential component of global energy;however,the processes of coal mining and utilization produce significant amounts of coal mine goafs,accompanied by coal-based solid wastes and emitted CO_(2),resulting in severe ecological and environmental challenges.In response to this issue,this study pro-poses a novel approach for filling coal mine goafs using cementitious materials prepared by coal-based solid wastes mineralized with CO_(2)(15%in concentration).The CO_(2) sequestration capacities of individual solid wastes are ranked as follows:carbide slag(CS)>red mud(RM)>fly ash(FA).The performance of filling material prepared from composite solid waste(FA-CS-RM)mineralized with CO_(2) meets the filling requirements of goaf.The filling material(F60C20R20)obtained by CO_(2) mineralization was 14.9 MPa in maximum compressive strength,increasing by 32.2%compared to the non-mineralized material.The prepared filling material exhibits excellent CO_(2) sequestration capacity(i.e.,14.4 kg·t^(−1) in maximum amount of CO_(2) sequestration).According to the analysis of carbon sequestration potential,in China,the annual production of FA,CS,and RM is approximately 899,30,and 107 Mt,respectively in the year of 2023.The utilization of FA,CS,and RM individually can achieve carbon emission reductions of 3.42,10.78,and 0.61 Mt,respectively.The composite solid waste(FA-CS-RM)mineralized with CO_(2) can achieve 1.23 Mt in carbon emissions reduction.Additionally,taking Yellow River Basin of China as a case study,the total volume of underground space in coal mine goafs from 2016 to 2030 is estimated at 8.16 Gm3,indicating that this technology can sequester 0.18 Gt of CO_(2).This approach offers a promising solution for large-scale flue gas CO_(2) sequestration,recycling coal-based solid wastes,and remediating coal mine goafs,contributing to green utilization of coal and the emission reduction of carbon.展开更多
Reclaimed mining-induced subsidence area soils (RMSs) could restore soil quality and crop productivity in coal mining area. This study was conducted to evaluate the effects of mineral-processing wastes (fly ash vs coa...Reclaimed mining-induced subsidence area soils (RMSs) could restore soil quality and crop productivity in coal mining area. This study was conducted to evaluate the effects of mineral-processing wastes (fly ash vs coal gangue) as backfill substrates on soil chemical and microbial properties in mining-induced subsidence area. A general higher water holding capacity (WHC) and pH had been observed in fly ash than coal gangue reconstructed soil. Soil microbial biomass C (MBC) and N (MBN), MBC/TOC (total organic carbon) ratio (qmic) were higher under the influence of the fly ash, while contents of As, Cr, C/Nbio, the basal respiration per unit of microbial biomass (QCO2) were higher under the coal gangue reconstructed mode in 0-10, 10-20, 20-50 cm layers. The microbial basal respiration was higher in 0-10, 10-20, 0-50 cm layers, while was lower in 20-50 cm layer under fly ash than that of coal gangue reconstructed mode. The lower QCO2 of fly ash mine soil suggested the lower maintenance energy requirement of the microbial community. Moreover, the contents of metals may possibly have negative implications for soil microbial and enzyme activities in reconstructed soil.展开更多
This study explores the use of black soldier fly larvae protein as a bio-based adhesive to produce particleboards from sugarcane bagasse.A comprehensive evaluation was conducted,including rheological characterization ...This study explores the use of black soldier fly larvae protein as a bio-based adhesive to produce particleboards from sugarcane bagasse.A comprehensive evaluation was conducted,including rheological characterization of the adhesive and physical–mechanical testing of the panels according to European standards.The black soldier fly larvae-based adhesive exhibited gel-like viscoelastic behavior,rapid partial structural recovery after shear,and favorable application properties.Particleboards manufactured with this adhesive and sugarcane bagasse achieved promising mechanical performance,with modulus of rupture and modulus of elasticity values of 30.2 and 3500 MPa,respectively.Internal bond strength exceeded 0.4 MPa,complying with European standard 312-3 specifications.For comparative purposes,a panel made with Eucalyptus grandis particles was also produced under the same conditions to demonstrate the versatility of the adhesive system.Compared to other bio-based and synthetic adhesives,this bio-based system showed competitive performance and derives from the bioconversion of organic residues.Protein adhesives were synthesized fromHermetia illucens larvae grown commercially on agriculturalwaste frompotato chip production,emphasizing the renewable origin of both the biomass and the final adhesive.These results highlight the potential of insect proteins as sustainable and circular alternatives for the wood panel industry.展开更多
The electromagnetic wave absorption of silicon carbide nanowires is improved by their uniform and diverse cross-structures.This study introduces a sustainable and high value-added method for synthesizing silicon carbi...The electromagnetic wave absorption of silicon carbide nanowires is improved by their uniform and diverse cross-structures.This study introduces a sustainable and high value-added method for synthesizing silicon carbide nanowires using lignite and waste silicon powder as raw materials through carbothermal reduction.The staggered structure of nanowires promotes the creation of interfacial polarization,impedance matching,and multiple loss mechanisms,leading to enhanced electromagnetic absorption performance.The silicon carbide nanowires demonstrate outstanding electromagnetic absorption capabilities with the minimum reflection loss of-48.09 d B at10.08 GHz and an effective absorption bandwidth(the reflection loss less than-10 d B)ranging from 8.54 to 16.68 GHz with a thickness of 2.17 mm.This research presents an innovative approach for utilizing solid waste in an environmentally friendly manner to produce broadband silicon carbide composite absorbers.展开更多
Industrial waste salts are commonly used to make value-added snow-melting agents to ensure traffic safety in northern China during winter and spring after snowfall.However,heavy metals in industrial waste salts may po...Industrial waste salts are commonly used to make value-added snow-melting agents to ensure traffic safety in northern China during winter and spring after snowfall.However,heavy metals in industrial waste salts may pose certain environmental risks.Snow-melting agents and snow samples were collected and analyzed from highways,arterial roads,footbridges,and other locations in Beijing after the snowstorm in December 2023.It was found that the main component of snow-melting agents was sodium chloride with high concentrations of Cu,Mn,and Zn,which are not regulated in the current policies,despite the recent promotion of environmentally friendly snow-melting agents.The Pb,Zn and Cr contents of some snow samples exceeded the limitation value of surface water quality standards,potentially affecting the soil and water environment near roadsides,although the snow-melting agents comply with relevant standards,which indicates the policy gap in the management of recycled industrial salts.We reviewed and analyzed the relevant standards for snow-melting agents and industrial waste salts proposed nationally and internationally over the past 30 years.Through comparative analysis,we proposed relevant policy recommendations to the existing quality standards of snow-melting agents and the management regulations of industrial waste salts,and the formulation of corresponding usage strategies,aimed at reducing the potential environmental release of heavy metals from the use of snow-melting agents,thereby promoting more sustainable green urban development and environmentally sound waste management.展开更多
Foliar uptake of airborne metal(loid)s plays a crucial role in metal(loid)accumulation in plant organs and is influ-enced by the size and emission sources of aerosols.Given the high enrichment of toxic metal(loid)s in...Foliar uptake of airborne metal(loid)s plays a crucial role in metal(loid)accumulation in plant organs and is influ-enced by the size and emission sources of aerosols.Given the high enrichment of toxic metal(loid)s in submicron-scale particulates(PM1),this study established a PM1 exposure system to examine airborne metal(loid)accu-mulation and foliar physiological responses in Oryza sativa L.The results showed that the concentrations of Cu,Zn,As,Pb,and Cd in the leaves and grains were influenced not only by the airborne metal(loid)levels but also by the specific nature of the PM1 particles.The quantitative model for PM1-associated Pb entry into leaf tissue indicated that foliar Pb accumulation was primarily driven by particle adhesion,followed by hydrophilic pene-tration and trans-stomatal liquid film migration,accounting for 87%–89%of the total accumulation.The strong hygroscopicity and high Pb activity of PM1 emitted from waste incineration(WI)increased the Pb absorption coefficient via the hydrophilic and liquid film migration pathway.In contrast,the high hydrophobicity of PM1 from coal burning(CB)led to greater retention of Pb on leaf surfaces.Both foliar reactive oxygen metabolism and photosynthesis indices were sensitive to air pollution.Foliar metal(loid)accumulation and airborne PM1 concentration accounted for the variance in physiological responses in rice leaves.Our results also indicated that Pb was the key element in PM1 emissions from both coal burning(CB)and waste incineration(WI)responsible for significant physiological changes in rice leaves.展开更多
Innovations of mining technologies were proposed by beneficial utilizations of unfavorable factors such as high geostress,high geotemperature and high mining depth to achieve green mining as mining depth increases ine...Innovations of mining technologies were proposed by beneficial utilizations of unfavorable factors such as high geostress,high geotemperature and high mining depth to achieve green mining as mining depth increases inevitably.Cuttability of deep hard rock was investigated by experimental and regressed analyses to find the reasonable stress adjustment method to improve non-explosive mechanized fragmentation for hard ore-rock.A non-explosive mechanized and intellectualized mining method was proposed to continuously and precisely exploit phosphate underground,which promoted the high-recovery,low-waste and high-efficiency exploitation of phosphate with recovery rate over 90%,dilution rate near 5%and cutting efficiency about 107.7 t/h.A circular economy model and the backfill system were proposed to conduct resource utilizations of solid waste,by which the utilization amount of waste increased year after year.In 2018,the utilization amounts of phosphogypsum,yellow phosphorus slag and waste rock increased to 1853.6×10^3 t/a,291.1×10^3 t/a and 1493.8×10^3 t/a,respectively.展开更多
The changes of vegetation compositions, plant species diversity, species important value and succession of plant community were studied on waste dumps in Haizhou opencast coalmine which is located in the west of Liaon...The changes of vegetation compositions, plant species diversity, species important value and succession of plant community were studied on waste dumps in Haizhou opencast coalmine which is located in the west of Liaoning Province, China (41°41(-42°56( N, 121°1(-122°56(E). Four kinds of terraces with different ages (5, 10, 20 and 40 years) were selected for investigation of plants. Total of 63 species of natural colonized plants were recorded on the waste dump and they belong to 23 families. The main families were Compositae (15 species), Fabaceae (11 species) and Leguminosae (8 species), which accounted for 54.0% of total species and play an important role in natural vegetation recovery in waste dump area. The dominant species on 5-, 10-, 20-, 40-year-old terraces were Tribulus terrestris + Echinochloa hispidula + Salsola collina, Echinochloa hispidula + Artemisia sieversiana + Artemisia scoparia, Echinochloa hispidula + Clinelymus dahuricus + Artemisia scoparia + Artemisia sieversiana + Melilotus officinalis, Clinelymus dahuricus+Phragmites communis + Echinochloa hispidula+ Setaria viridis, respectively. According to the important value of species calculated. It is determined that Tribulus terrestris can act as pioneer species on waste dump and Clinelymus dahuricus, Phragmites communis and Echinochloah hispidula are important dominant species in vegetation restoration in Haizhou opencast coalmine. The study results can provide scientific basis for selecting and disposing appropriately plant species and rehabilitating vegetation on waste dumps of coalmine.展开更多
Proper treatment of acidleaching tailings(ALTs)of vanadiumbearing stone coal minerals is of great urgency.One approach is adding it into the raw materials during the preparation of lightweight aggregate(LWA).But clay ...Proper treatment of acidleaching tailings(ALTs)of vanadiumbearing stone coal minerals is of great urgency.One approach is adding it into the raw materials during the preparation of lightweight aggregate(LWA).But clay is always needed.In this paper,another solid waste,red mud,was mixed with ALTs as a source of flux components instead of clay.Evaluation of the physical characteristics,morphological structures,as well as crystal phases during the sintering process were investigated.When their mixtures with a proper ratio were sintered at 1080℃,a glassy phase with certain viscosity was formed,and the gases generated simultaneously were encapsulated by the melt.Finally,LWA with a onehour water absorption as low as 1.46%,a bulk density as low as 728.76 kgm 3 and a compressive strength as high as 10.77 MPa was fabricated.展开更多
Mine tailing soils created from the copper extraction in Touro Mine （Northwest Spain） are very degraded both physically and chemically. Three plots in this mine tailing were amended with Technosols in different prop...Mine tailing soils created from the copper extraction in Touro Mine （Northwest Spain） are very degraded both physically and chemically. Three plots in this mine tailing were amended with Technosols in different proportions in each one to know if this mixture improved the physico-chemical characteristics of the mine soil and contaminated it with heavy metals. The Technosols were made of organic wastes, including mussel residues, wood fragments, sewage sludges and paper mill ashes. An unamended area was used as a control soil. Pseudototal and diethylenetriaminepentaacetic acid （DTPA）-extractable contents of A1, Cr, Cu, Fe, Mn, Ni, Pb and Zn were determined in soil samples. The untreated soil had significant limitations for vegetation growth. All the Technosols improved the properties of the mine soil by increasing organic carbon and pH value, but they added Ni, Pb or Zn to the soil. It is advisable to check whether the heavy metal concentrations of the wastes are hazardous or not before adding to soils. It is also necessary to study the effect of these wastes over time and in more areas to conclude if they are actually favourable to restore degraded mine soils.展开更多
Amine functional group was grafted to obtain modified persimmon waste gel （NH2-CPT） with the focus of development of selective recovery of molybdenum from rhenium. The adsorption behavior of the NH2-CPT gel for vari...Amine functional group was grafted to obtain modified persimmon waste gel （NH2-CPT） with the focus of development of selective recovery of molybdenum from rhenium. The adsorption behavior of the NH2-CPT gel for various metal ions at varying hydrochloric acid concen-trations was studied. It is found that the NH2-CPT exhibits high affinity for Mo（VI） and no affinity for Re（VII）, Cu（II）, Fe（III）, Mn（VII）, and Zn（II） under the operating conditions. The maximum adsorption capacity for Mo（VI） is 172 mg·g^-1, and the adsorption behavior obeys the Langmuir model. Owing to Mo（VI） as poly-anions, the adsorption mechanism of molybdenum anions could be explained as the anion exchange reactions at weak acid concentration, while neutral molecules could be explained as the complexation reactions at strong acid concentration, respectively. In addition, its excellent adsorption characteristics for Mo（VI） are confirmed by separation of Mo（VI） from Mo to Re containing industrial effluent.展开更多
Coal is the vital resource of energy in China,but abandoned coal ash and gangue lead to the degradation of vegetation cover and reduce soil quality.Both arbuscular mycorrhizal fungi (AMF) and phosphate solubilizing ba...Coal is the vital resource of energy in China,but abandoned coal ash and gangue lead to the degradation of vegetation cover and reduce soil quality.Both arbuscular mycorrhizal fungi (AMF) and phosphate solubilizing bacteria (PSB) play a key role in biogeochemical cycle such as soil organic matter decomposition,nutrition release,and energy flow.To improve and reclamation the soil quality and ecological efficiency of the coal mining waste,we investigated the effects of an AMF strain (Glomus mosseae) and a PSB strain (Pantoesstewarti) on phytate mineralization and subsequent transfer to the host plant (Medicago sativa L.) using a two-compartment microcosm with a central 30 mm nylon mesh barrier.The results showed that significantly higher available P (AP),above ground biomass (AGB) and underground biomass (UGB) were in combined inoculation of AMF-PSB than other treatments in root and hyphae compartment.The microbial inoculum of the AMF or PSB had a significant influence on soil acid phosphatase activities (ACP).AMF-PSB enhanced phytate mineralization,improved plant biomass.AP and ACP positively influenced the AGB and UGB.AMF-PSB could be used as bioinoculant to enhance sustainable production of the plant in abandoned solid waste of coal mine.展开更多
Based on investigation of the characteristics of solid waste of two different mines, the Fenghuangshan copper mine and the Xinqiao pyrite mine in Tongling, Anhui province in central-east China, the possibility and the...Based on investigation of the characteristics of solid waste of two different mines, the Fenghuangshan copper mine and the Xinqiao pyrite mine in Tongling, Anhui province in central-east China, the possibility and the differences of acid mine drainage （AMD） of the railings and the waste rocks are discussed, and the modes of occurrence of heavy metal elements in the mine solid waste are also studied. The Fenghuangshan copper mine hardly produces AMD, whereas the Xinqiao pyrite mine does and there are also differences in the modes of occurrence of heavy metal elements in the railings. For the former, toxic heavy metals such as Cu, Pb, Zn, Cd, As and Hg exist mostly in the slag mode, as compared to the latter, where the deoxidization mode has a much higher content, indicating that large amounts minerals in the waste rocks have begun to oxidize at the earth surface. AMD is proved to promote the migration and spread of the heavy metals in mining waste rocks and lead to environmental pollution of the surroundings of the mine area.展开更多
文摘A flower-like BiOBr photocatalyst(CS/BiOBr)was prepared by using the carbon material derived from corn straw(CS)as the carrier.The prepared composites were characterized by X-ray diffraction(XRD),Fourier transform infrared(FIIR)spectra,scanning electron microscope(SEM),X-ray photoelectron spectra(XPS),and UV-Vis diffuse reflectance spectra(UV-Vis DRS).The SEM analyses indicate that the introduction of CS promotes the formation of a unique flower-like structure in BiOBr,which not only optimizes the efficiency of light capture but also increases the specific surface area of BiOBr.The bandgap of the composite was narrower compared with the pure BiOBr.The CS/BiOBr composites exhibited higher photocatalytic activity than pure CS and BiOBr under visible light irradiation,and a higher first-order reaction rate constant(k)of 0.0437 min-1 than BiOBr(0.0146 min^(-1)),and exhibited excellent stability and reusability during the cyclic run.The enhanced photocatalytic activity is attributed to the efficient separation of photoinduced electrons and holes.Superoxide radicals and holes were the major active species.
基金financial support from the International Research Chairs Initiativea program funded by the International Development Research Centre,Canada(IDRC)facilitated by the Canadian Research Chairs Program(108469-001 and 109418-006).
文摘Jerada coal mining generates extensive coal mine waste rock(CMWR)piles rich in valuable minerals,posing environmental challenges and economic opportunities.This study examines reprocessing feasibility through 3D geometallurgical characterization.Sampling used down the hole hammer drilling technique(DTH)and drone surveys for topographical precision.Over 620 samples from(T01,T02,T08)underwent comprehensive analyses including particle size distribution,x-ray fluorescence(XRF),total sulfur/carbon analysis(S/C),and inductively coupled plasma mass spectrometry(ICP-MS)for physical-chemical characterization.Mineralogical aspects were explored via optical microscopy(OM),X-ray diffraction(XRD),scanning electron microscopy(SEM),electron probe microanalysis(EPMA),and laser ablation inductively coupled plasma mass spectrometry(LA-ICP-MS).Quantitative mineral evaluation by scanning electron microscope(QEMSCAN)provided mineral insights.Chemical data was used in a 3D block model to quantify residual coal.Results for the three examined CMWR piles(T01,T02,and T08)showed varying D80 from 160 to 300μm,notable carbon content averaged 12.5 wt%(T01),16 wt%(T02),and 8.5 wt%(T08).Sulfur presence exceeded 1 wt%in T08,and potential environmental concerns due to iron sulfides.Anthracite liberation was below 30 wt%.3D modeling estimated a total volume of 7 Mm3,mainly from T08,equaling 11.2 Mt.With its high carbon content and substantial tonnages,re-exploitation or alternative applications could minimize these CMWR piles environmental impact.
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supported by the National Key Research and Development Program of China(2024YFC2909500)State Key Laboratory of Intelligent Construction and Healthy Operation and Maintenance of Deep Underground Engineering(SDGZ2505)National Natural Science Foundation of China(42377148)。
文摘High-steep waste dumps in open-pit mines frequently demonstrate complex particle-size distributions and fractal characteristics along their slopes,which have a significant impact on slope stability.This study takes the Dasuji South waste dump in Inner Mongolia as a case to quantify the fractal dimensions of soil-rock mixtures at various slope heights,and to clarify how these fractal properties govern shear strength and deformation behavior under overlying stress,thereby affecting the overall stability of the waste dump slope.Field sampling and laboratory tests were conducted to determine the particle-size composition and fractal dimensions while direct shear tests were conducted and revealed that lower fractal dimensions indicating coarser particle assemblages significantly enhance shear resistance.Complementary PFC_(2)D discrete element simulations demonstrate that slopes composed of lower-fractaldimension materials deform less and contain localized deformation zones,whereas higher-fractal-dimension slopes experience more extensive displacement and a heightened risk of landslides.These findings refine our understanding of the relationship between fractal grain-size distribution and slope stability,providing a robust theoretical basis for improved stability assessment and optimized support strategies in deep open-pit mining waste dumps,and ultimately aiding in more effective disaster prevention within geotechnical engineering.
基金Project(2024JJ2074) supported by the Natural Science Foundation of Hunan Province,ChinaProject(22376221) supported by the National Natural Science Foundation of ChinaProject(2023QNRC001) supported by the Young Elite Scientists Sponsorship Program by CAST,China。
文摘Driven by rapid technological advancements and economic growth,mineral extraction and metal refining have increased dramatically,generating huge volumes of tailings and mine waste(TMWs).Investigating the morphological fractions of heavy metals and metalloids(HMMs)in TMWs is key to evaluating their leaching potential into the environment;however,traditional experiments are time-consuming and labor-intensive.In this study,10 machine learning(ML)algorithms were used and compared for rapidly predicting the morphological fractions of HMMs in TMWs.A dataset comprising 2376 data points was used,with mineral composition,elemental properties,and total concentration used as inputs and concentration of morphological fraction used as output.After grid search optimization,the extra tree model performed the best,achieving coefficient of determination(R2)of 0.946 and 0.942 on the validation and test sets,respectively.Electronegativity was found to have the greatest impact on the morphological fraction.The models’performance was enhanced by applying an ensemble method to the top three optimal ML models,including gradient boosting decision tree,extra trees and categorical boosting.Overall,the proposed framework can accurately predict the concentrations of different morphological fractions of HMMs in TMWs.This approach can minimize detection time,aid in the safe management and recovery of TMWs.
基金initiated and financially supported by Stevenson Aggregates and Fulton Hogan.
文摘Safety berms(also called safety bunds or windrows),widely employed in surface mining and quarry operations,are typically designed based on rules of thumb.Despite having been used by the industry for more than half a century and accidents happening regularly,their behaviour is still poorly understood.This paper challenges existing practices through a comprehensive investigation combining full-scale experiments and advanced numerical modelling.Focusing on a Volvo A45G articulated dump truck(ADT)and a CAT 773B rigid dump truck(RDT),collision scenarios under various approach conditions and different safety berm geometries and materials are rigorously examined.The calibrated numerical model is used to assess the energy absorption capacity of safety berms with different geometry and to predict a critical velocity for a specific scenario.Back analysis of an actual fatal accident indicated that an ADT adhering to the speed limit could not be stopped by the safety berm designed under current guidelines.The study highlights the importance of considering the entire geometry and the mass and volume of the material used to build the safety berm alongside the speed and approach conditions of the machinery.The findings of the study enable operators to set speed limits based on specific berm geometries or adapt safety berm designs to match speed constraints for specific machinery.This will reduce the risk of fatal accidents and improve haul road safety.
基金supported by the National Natural Science Foundation of China(U21A20321 and 22378241)Research Project Supported by Shanxi Scholarship Council of China(2024-015).
文摘Coal is an essential component of global energy;however,the processes of coal mining and utilization produce significant amounts of coal mine goafs,accompanied by coal-based solid wastes and emitted CO_(2),resulting in severe ecological and environmental challenges.In response to this issue,this study pro-poses a novel approach for filling coal mine goafs using cementitious materials prepared by coal-based solid wastes mineralized with CO_(2)(15%in concentration).The CO_(2) sequestration capacities of individual solid wastes are ranked as follows:carbide slag(CS)>red mud(RM)>fly ash(FA).The performance of filling material prepared from composite solid waste(FA-CS-RM)mineralized with CO_(2) meets the filling requirements of goaf.The filling material(F60C20R20)obtained by CO_(2) mineralization was 14.9 MPa in maximum compressive strength,increasing by 32.2%compared to the non-mineralized material.The prepared filling material exhibits excellent CO_(2) sequestration capacity(i.e.,14.4 kg·t^(−1) in maximum amount of CO_(2) sequestration).According to the analysis of carbon sequestration potential,in China,the annual production of FA,CS,and RM is approximately 899,30,and 107 Mt,respectively in the year of 2023.The utilization of FA,CS,and RM individually can achieve carbon emission reductions of 3.42,10.78,and 0.61 Mt,respectively.The composite solid waste(FA-CS-RM)mineralized with CO_(2) can achieve 1.23 Mt in carbon emissions reduction.Additionally,taking Yellow River Basin of China as a case study,the total volume of underground space in coal mine goafs from 2016 to 2030 is estimated at 8.16 Gm3,indicating that this technology can sequester 0.18 Gt of CO_(2).This approach offers a promising solution for large-scale flue gas CO_(2) sequestration,recycling coal-based solid wastes,and remediating coal mine goafs,contributing to green utilization of coal and the emission reduction of carbon.
基金Projects(2013CB227904)supported by the National Basic Research Program of ChinaProjects(2011QNB13)supported by Fundamental Research Funds for the Central Universities,ChinaProjects(51374208,51004100)supported by the National Natural Science Foundation of China
文摘Reclaimed mining-induced subsidence area soils (RMSs) could restore soil quality and crop productivity in coal mining area. This study was conducted to evaluate the effects of mineral-processing wastes (fly ash vs coal gangue) as backfill substrates on soil chemical and microbial properties in mining-induced subsidence area. A general higher water holding capacity (WHC) and pH had been observed in fly ash than coal gangue reconstructed soil. Soil microbial biomass C (MBC) and N (MBN), MBC/TOC (total organic carbon) ratio (qmic) were higher under the influence of the fly ash, while contents of As, Cr, C/Nbio, the basal respiration per unit of microbial biomass (QCO2) were higher under the coal gangue reconstructed mode in 0-10, 10-20, 20-50 cm layers. The microbial basal respiration was higher in 0-10, 10-20, 0-50 cm layers, while was lower in 20-50 cm layer under fly ash than that of coal gangue reconstructed mode. The lower QCO2 of fly ash mine soil suggested the lower maintenance energy requirement of the microbial community. Moreover, the contents of metals may possibly have negative implications for soil microbial and enzyme activities in reconstructed soil.
基金supported by the Consejo Nacional de Investigaciones Cientificas y Tecnicas(CONICET)via grant Proyectos de Investigacion Plurianuales(PIP 2021:2894)Agencia I+D+i via grant Proyectos de Investigacion Cientifica y Tecnologica(PICT-2021-I-A-00294).
文摘This study explores the use of black soldier fly larvae protein as a bio-based adhesive to produce particleboards from sugarcane bagasse.A comprehensive evaluation was conducted,including rheological characterization of the adhesive and physical–mechanical testing of the panels according to European standards.The black soldier fly larvae-based adhesive exhibited gel-like viscoelastic behavior,rapid partial structural recovery after shear,and favorable application properties.Particleboards manufactured with this adhesive and sugarcane bagasse achieved promising mechanical performance,with modulus of rupture and modulus of elasticity values of 30.2 and 3500 MPa,respectively.Internal bond strength exceeded 0.4 MPa,complying with European standard 312-3 specifications.For comparative purposes,a panel made with Eucalyptus grandis particles was also produced under the same conditions to demonstrate the versatility of the adhesive system.Compared to other bio-based and synthetic adhesives,this bio-based system showed competitive performance and derives from the bioconversion of organic residues.Protein adhesives were synthesized fromHermetia illucens larvae grown commercially on agriculturalwaste frompotato chip production,emphasizing the renewable origin of both the biomass and the final adhesive.These results highlight the potential of insect proteins as sustainable and circular alternatives for the wood panel industry.
基金supported by the National Natural Science Foundation of China(No.52436008)the Inner Mongolia Science and Technology Projects,China(Nos.JMRHZX20210003 and 2023YFCY0009)+3 种基金the Huaneng Group Co Ltd.,China(No.HNKJ23-H50)the National Natural Science Foundation of China(No.22408044)the China Postdoctoral Science Foundation(No.2024M761877)the National Key R&D Program of China(No.SQ2024YFD2200039)。
文摘The electromagnetic wave absorption of silicon carbide nanowires is improved by their uniform and diverse cross-structures.This study introduces a sustainable and high value-added method for synthesizing silicon carbide nanowires using lignite and waste silicon powder as raw materials through carbothermal reduction.The staggered structure of nanowires promotes the creation of interfacial polarization,impedance matching,and multiple loss mechanisms,leading to enhanced electromagnetic absorption performance.The silicon carbide nanowires demonstrate outstanding electromagnetic absorption capabilities with the minimum reflection loss of-48.09 d B at10.08 GHz and an effective absorption bandwidth(the reflection loss less than-10 d B)ranging from 8.54 to 16.68 GHz with a thickness of 2.17 mm.This research presents an innovative approach for utilizing solid waste in an environmentally friendly manner to produce broadband silicon carbide composite absorbers.
基金supported by the National Natural Science Foundation of China(No.22176200)the Industrial Innovation Entrepreneurial Team Project of Ordos 2021.
文摘Industrial waste salts are commonly used to make value-added snow-melting agents to ensure traffic safety in northern China during winter and spring after snowfall.However,heavy metals in industrial waste salts may pose certain environmental risks.Snow-melting agents and snow samples were collected and analyzed from highways,arterial roads,footbridges,and other locations in Beijing after the snowstorm in December 2023.It was found that the main component of snow-melting agents was sodium chloride with high concentrations of Cu,Mn,and Zn,which are not regulated in the current policies,despite the recent promotion of environmentally friendly snow-melting agents.The Pb,Zn and Cr contents of some snow samples exceeded the limitation value of surface water quality standards,potentially affecting the soil and water environment near roadsides,although the snow-melting agents comply with relevant standards,which indicates the policy gap in the management of recycled industrial salts.We reviewed and analyzed the relevant standards for snow-melting agents and industrial waste salts proposed nationally and internationally over the past 30 years.Through comparative analysis,we proposed relevant policy recommendations to the existing quality standards of snow-melting agents and the management regulations of industrial waste salts,and the formulation of corresponding usage strategies,aimed at reducing the potential environmental release of heavy metals from the use of snow-melting agents,thereby promoting more sustainable green urban development and environmentally sound waste management.
基金supported by a grant from NIH(R01AI132695)to RM。
文摘Chronic wasting disease—a prion disease affecting cervids:Many neurological conditions,including Alzheimer's and Parkinson's diseases,amyotrophic lateral sclerosis,frontotemporal dementias,among others,are caused by the accumulation of misfolded proteins in the brain.These diseases affect not only humans,but also animals.
基金supported by the National Natural Science Foundation of China(Nos.42077367 and 21677123).
文摘Foliar uptake of airborne metal(loid)s plays a crucial role in metal(loid)accumulation in plant organs and is influ-enced by the size and emission sources of aerosols.Given the high enrichment of toxic metal(loid)s in submicron-scale particulates(PM1),this study established a PM1 exposure system to examine airborne metal(loid)accu-mulation and foliar physiological responses in Oryza sativa L.The results showed that the concentrations of Cu,Zn,As,Pb,and Cd in the leaves and grains were influenced not only by the airborne metal(loid)levels but also by the specific nature of the PM1 particles.The quantitative model for PM1-associated Pb entry into leaf tissue indicated that foliar Pb accumulation was primarily driven by particle adhesion,followed by hydrophilic pene-tration and trans-stomatal liquid film migration,accounting for 87%–89%of the total accumulation.The strong hygroscopicity and high Pb activity of PM1 emitted from waste incineration(WI)increased the Pb absorption coefficient via the hydrophilic and liquid film migration pathway.In contrast,the high hydrophobicity of PM1 from coal burning(CB)led to greater retention of Pb on leaf surfaces.Both foliar reactive oxygen metabolism and photosynthesis indices were sensitive to air pollution.Foliar metal(loid)accumulation and airborne PM1 concentration accounted for the variance in physiological responses in rice leaves.Our results also indicated that Pb was the key element in PM1 emissions from both coal burning(CB)and waste incineration(WI)responsible for significant physiological changes in rice leaves.
基金Projects(41630642,51904335,51904333)supported by the National Natural Science Foundation of China
文摘Innovations of mining technologies were proposed by beneficial utilizations of unfavorable factors such as high geostress,high geotemperature and high mining depth to achieve green mining as mining depth increases inevitably.Cuttability of deep hard rock was investigated by experimental and regressed analyses to find the reasonable stress adjustment method to improve non-explosive mechanized fragmentation for hard ore-rock.A non-explosive mechanized and intellectualized mining method was proposed to continuously and precisely exploit phosphate underground,which promoted the high-recovery,low-waste and high-efficiency exploitation of phosphate with recovery rate over 90%,dilution rate near 5%and cutting efficiency about 107.7 t/h.A circular economy model and the backfill system were proposed to conduct resource utilizations of solid waste,by which the utilization amount of waste increased year after year.In 2018,the utilization amounts of phosphogypsum,yellow phosphorus slag and waste rock increased to 1853.6×10^3 t/a,291.1×10^3 t/a and 1493.8×10^3 t/a,respectively.
文摘The changes of vegetation compositions, plant species diversity, species important value and succession of plant community were studied on waste dumps in Haizhou opencast coalmine which is located in the west of Liaoning Province, China (41°41(-42°56( N, 121°1(-122°56(E). Four kinds of terraces with different ages (5, 10, 20 and 40 years) were selected for investigation of plants. Total of 63 species of natural colonized plants were recorded on the waste dump and they belong to 23 families. The main families were Compositae (15 species), Fabaceae (11 species) and Leguminosae (8 species), which accounted for 54.0% of total species and play an important role in natural vegetation recovery in waste dump area. The dominant species on 5-, 10-, 20-, 40-year-old terraces were Tribulus terrestris + Echinochloa hispidula + Salsola collina, Echinochloa hispidula + Artemisia sieversiana + Artemisia scoparia, Echinochloa hispidula + Clinelymus dahuricus + Artemisia scoparia + Artemisia sieversiana + Melilotus officinalis, Clinelymus dahuricus+Phragmites communis + Echinochloa hispidula+ Setaria viridis, respectively. According to the important value of species calculated. It is determined that Tribulus terrestris can act as pioneer species on waste dump and Clinelymus dahuricus, Phragmites communis and Echinochloah hispidula are important dominant species in vegetation restoration in Haizhou opencast coalmine. The study results can provide scientific basis for selecting and disposing appropriately plant species and rehabilitating vegetation on waste dumps of coalmine.
文摘Proper treatment of acidleaching tailings(ALTs)of vanadiumbearing stone coal minerals is of great urgency.One approach is adding it into the raw materials during the preparation of lightweight aggregate(LWA).But clay is always needed.In this paper,another solid waste,red mud,was mixed with ALTs as a source of flux components instead of clay.Evaluation of the physical characteristics,morphological structures,as well as crystal phases during the sintering process were investigated.When their mixtures with a proper ratio were sintered at 1080℃,a glassy phase with certain viscosity was formed,and the gases generated simultaneously were encapsulated by the melt.Finally,LWA with a onehour water absorption as low as 1.46%,a bulk density as low as 728.76 kgm 3 and a compressive strength as high as 10.77 MPa was fabricated.
文摘Mine tailing soils created from the copper extraction in Touro Mine （Northwest Spain） are very degraded both physically and chemically. Three plots in this mine tailing were amended with Technosols in different proportions in each one to know if this mixture improved the physico-chemical characteristics of the mine soil and contaminated it with heavy metals. The Technosols were made of organic wastes, including mussel residues, wood fragments, sewage sludges and paper mill ashes. An unamended area was used as a control soil. Pseudototal and diethylenetriaminepentaacetic acid （DTPA）-extractable contents of A1, Cr, Cu, Fe, Mn, Ni, Pb and Zn were determined in soil samples. The untreated soil had significant limitations for vegetation growth. All the Technosols improved the properties of the mine soil by increasing organic carbon and pH value, but they added Ni, Pb or Zn to the soil. It is advisable to check whether the heavy metal concentrations of the wastes are hazardous or not before adding to soils. It is also necessary to study the effect of these wastes over time and in more areas to conclude if they are actually favourable to restore degraded mine soils.
基金financially supported by the National Natural Science Foundation of China(Nos.21171080 and21201094)the National Science and Technology Pillar Program(No.2012BAF03B02)+1 种基金the Scientific Research Foundation for the Returned Overseas Chinese Scholars,State Education Ministry(No.2011-1139)the Program for Liaoning Excellent Talents in University(No.LJQ2012001)
文摘Amine functional group was grafted to obtain modified persimmon waste gel （NH2-CPT） with the focus of development of selective recovery of molybdenum from rhenium. The adsorption behavior of the NH2-CPT gel for various metal ions at varying hydrochloric acid concen-trations was studied. It is found that the NH2-CPT exhibits high affinity for Mo（VI） and no affinity for Re（VII）, Cu（II）, Fe（III）, Mn（VII）, and Zn（II） under the operating conditions. The maximum adsorption capacity for Mo（VI） is 172 mg·g^-1, and the adsorption behavior obeys the Langmuir model. Owing to Mo（VI） as poly-anions, the adsorption mechanism of molybdenum anions could be explained as the anion exchange reactions at weak acid concentration, while neutral molecules could be explained as the complexation reactions at strong acid concentration, respectively. In addition, its excellent adsorption characteristics for Mo（VI） are confirmed by separation of Mo（VI） from Mo to Re containing industrial effluent.
基金We gratefully acknowledge the State Key Research Development Program of China(Grant No.2016YFC0501106)and the National Natural Science Foundation of China(Project 51574253).
文摘Coal is the vital resource of energy in China,but abandoned coal ash and gangue lead to the degradation of vegetation cover and reduce soil quality.Both arbuscular mycorrhizal fungi (AMF) and phosphate solubilizing bacteria (PSB) play a key role in biogeochemical cycle such as soil organic matter decomposition,nutrition release,and energy flow.To improve and reclamation the soil quality and ecological efficiency of the coal mining waste,we investigated the effects of an AMF strain (Glomus mosseae) and a PSB strain (Pantoesstewarti) on phytate mineralization and subsequent transfer to the host plant (Medicago sativa L.) using a two-compartment microcosm with a central 30 mm nylon mesh barrier.The results showed that significantly higher available P (AP),above ground biomass (AGB) and underground biomass (UGB) were in combined inoculation of AMF-PSB than other treatments in root and hyphae compartment.The microbial inoculum of the AMF or PSB had a significant influence on soil acid phosphatase activities (ACP).AMF-PSB enhanced phytate mineralization,improved plant biomass.AP and ACP positively influenced the AGB and UGB.AMF-PSB could be used as bioinoculant to enhance sustainable production of the plant in abandoned solid waste of coal mine.
基金supported by the National Natural Science Foundation of China(Nos 40452072 and 40472026)the National Natural Science Foundation of Anhui province.
文摘Based on investigation of the characteristics of solid waste of two different mines, the Fenghuangshan copper mine and the Xinqiao pyrite mine in Tongling, Anhui province in central-east China, the possibility and the differences of acid mine drainage （AMD） of the railings and the waste rocks are discussed, and the modes of occurrence of heavy metal elements in the mine solid waste are also studied. The Fenghuangshan copper mine hardly produces AMD, whereas the Xinqiao pyrite mine does and there are also differences in the modes of occurrence of heavy metal elements in the railings. For the former, toxic heavy metals such as Cu, Pb, Zn, Cd, As and Hg exist mostly in the slag mode, as compared to the latter, where the deoxidization mode has a much higher content, indicating that large amounts minerals in the waste rocks have begun to oxidize at the earth surface. AMD is proved to promote the migration and spread of the heavy metals in mining waste rocks and lead to environmental pollution of the surroundings of the mine area.
