Traditional polymeric photocatalysts are typically constructed using aromatic building blocks to enhanceπ-conjugation.However,their inherent hydrophobicity and rigid structure lead to poor dispersibility in aqueous s...Traditional polymeric photocatalysts are typically constructed using aromatic building blocks to enhanceπ-conjugation.However,their inherent hydrophobicity and rigid structure lead to poor dispersibility in aqueous solutions,resulting in significant optical losses and exciton recombination.In this study,two series of six novel polymer photocatalysts(FLUSO,FLUSO-PEG10,FLUSO-PEG30;CPDTSO,CPDTSO-PEG10,CPDTSO-PEG30)are designed and synthesized by incorporating the hydrophilic,non-conjugated polyethylene glycol(PEG)chain,into both the main and side chains of polymers.By precisely optimizing the ratio of hydrophilic PEG segments,the water dispersibility is significantly improved while the light absorption capability of the polymer photocatalysts is well maintained.The experimental results confirm that the optimized FLUSO-PEG10 exhibits excellent photocatalytic hydrogen evolution rate,reaching up to 33.9 mmol/(g·h),which is nearly three times higher than that of fullyπ-conjugated counterparts.Water contact angles and particle size analyses reveal that incorporating non-conjugated segments into the main chains enhances the capacitance of the polymer/water interface and reduces particle aggregation,leading to improved photocatalyst dispersion and enhanced charge generation.展开更多
Considering the special features of dynamic environment economic dispatch of power systems with high dimensionality,strong coupling,nonlinearity,and non-convexity,a GA-DE multi-objective optimization algorithm based o...Considering the special features of dynamic environment economic dispatch of power systems with high dimensionality,strong coupling,nonlinearity,and non-convexity,a GA-DE multi-objective optimization algorithm based on dual-population pseudo-parallel genetic algorithm-differential evolution is proposed in this paper.The algorithm is based on external elite archive and Pareto dominance,and it adopts the cooperative co-evolution mechanism of differential evolution and genetic algorithm.Average entropy and cubic chaoticmapping initialization strategies are proposed to increase population diversity.In the proposed method,we analyze the distribution of neighboring solutions and apply a new Pareto solution set pruning approach.Unlike traditional models,this work takes the transmission losses as an optimization target and overcomes complex model constraints through a dynamic relaxation constraint approach.To solve the uncertainty caused by integrating wind and photovoltaic energy in power system scheduling,a multi-objective dynamic environment economical dispatch model is set up that takes the system spinning reserve and network highest losses into account.In this paper,the DE algorithm is improved to form the DGAGE algorithm for the objective optimization of the overall power system,The DE algorithm part of DGAGE is combined with the JAYA algorithm to form the system scheduling HDJ algorithm for multiple energy sources connected to the grid.The effectiveness of the proposed method is demonstrated using CEC2022 and CEC2005 test functions,showing robust optimization performance.Validation on a classical 10-unit system confirms the feasibility of the proposed algorithm in addressing power system scheduling issues.This approach provides a novel solution for dynamic power dispatch systems.展开更多
The flotation separation of argentite from sphalerite using ammonium dibutyl dithiophosphate(ADD)was studied.Molecular simulation(MS)calculation shows that ADD is chemisorbed on argentite and sphalerite surface in the...The flotation separation of argentite from sphalerite using ammonium dibutyl dithiophosphate(ADD)was studied.Molecular simulation(MS)calculation shows that ADD is chemisorbed on argentite and sphalerite surface in the form of S—P bond.The ADD adsorption on argentite and sphalerite surface in Ag^(+)system was revealed by ICP,Zeta potential and XPS analyses.It is shown that the dissolved Ag^(+)from argentite surface can be absorbed on sphalerite surface in the form of silver hydroxide,and AgOH hydrophilic colloid prevents the adsorption of ADD on sphalerite surface.The ADD adsorption on argentite and sphalerite surface in the pulp containing silver and zinc ions was revealed by adsorption capacity and surface wettability analyses.It is shown that the combined Zn(OH)_(2) and AgOH hydrophilic colloid leads to greater ADD adsorption capacity on argentite surface and stronger surface hydrophobicity than sphalerite.Flotation tests demonstrate that ADD enables efficient separation of argentite from sphalerite in the pulp containing silver and zinc ions.展开更多
Rural domestic sewage treatment is critical for environmental protection.This study defines the spatial pattern of villages from the perspective of rural sewage treatment and develops an integrated decision-making sys...Rural domestic sewage treatment is critical for environmental protection.This study defines the spatial pattern of villages from the perspective of rural sewage treatment and develops an integrated decision-making system to propose a sewage treatment mode and scheme suitable for local conditions.By considering the village spatial layout and terrain factors,a decision tree model of residential density and terrain type was constructed with accuracies of 76.47%and 96.00%,respectively.Combined with binary classification probability unit regression,an appropriate sewage treatment mode for the village was determined with 87.00%accuracy.The Analytic Hierarchy Process(AHP),combined with the Technique for Order Preference(TOPSIS)by Similarity to an Ideal Solution model,formed the basis for optimal treatment process selection under different emission standards.Verification was conducted in 542 villages across three counties of the Inner Mongolia Autonomous Region,focusing on the standard effluent effect(0.3773),low investment cost(0.3196),and high standard effluent effect(0.5115)to determine the best treatment process for the same emission standard under different needs.The annual environmental and carbon emission benefits of sewage treatment in these villages were estimated.This model matches village density,geographic feature,and social development level,and provides scientific support and a theoretical basis for rural sewage treatment decision-making.展开更多
Tafoni are a type of cavernous weathering features widespread in different climate zones around the world,but their origin has not been fully understood.Little attention was paid on tafoni in conglomerates.Danxiashan ...Tafoni are a type of cavernous weathering features widespread in different climate zones around the world,but their origin has not been fully understood.Little attention was paid on tafoni in conglomerates.Danxiashan UNESCO Global Geopark,located within the subtropic humid region of South China,has a landscape of large tafoni that occur on cliffs of red conglomerates.Both the Dinosaur Rock and Pagoda Peak of the geopark were selected to investigate the formation mechanisms of tafoni in conglomerates.During the field investigation,the size,rock hardness,and the external and internal meteorology of tafoni were measured and tested.The texture and composition of rock samples were observed,and the ion chromatography experiments were performed as well.Results show that tafoni have well ellipsoidal openings.Clasts of the conglomerates are largely sub-rounded and poorly sorted,and the cement is dominantly composed of calcite and iron oxide.The hardness of the lips is almost equal to that of the columns,and both are slightly higher than the backwalls.Compared with the external intense environmental changes,the interior of the tafoni is characterized by smaller temperature and relative humidity ranges and windless condition.Therefore,the porous and permeable conglomerates provide favorable lithology for tafoni development,and the micro-environment within the caverns is conducive to improving water utilization efficiency and enhancing salt weathering.The salts mainly consist of sulfates and nitrates,which might be derived from frequent raining,water evaporation and red beds as well.Consequently,tafoni are the result of the synergistic effects by multiple factors,rather than a single mechanism.展开更多
Based on the carrying capacity of the resources and the environment,this article defines the connotation of the land multifunctional space(LMFS)from three aspects,ecological protection,agricultural production and urba...Based on the carrying capacity of the resources and the environment,this article defines the connotation of the land multifunctional space(LMFS)from three aspects,ecological protection,agricultural production and urban construction,in the new era of land space planning system.Moreover,a framework is constructed for the coordinated development of the multi-functional oriented space to match the use of land space(ULS)with the supply of resources and environment(SRE).Based on this,the technology and methods of comprehensive evaluation,dominance recognition,and matching relationship division functions of the use of land space(FULS)and functions of the supply of resources and environment(FSRE)are discussed.The advantageous functions of the use of land space(AFULS)and advantageous functions of the supply of resources and environment(AFSRE)are also identified in the study area.A LMFS coordinated development system integrating“function position-comprehensive partition-regulation strategy”is proposed.Through the empirical study of Shandong province,we found that,first,the FULS of ecological protection space in the province is mainly found in high value areas,and the FSRE is mainly in low value areas,which has certain complementarity in the space.The FULS of agricultural production space is mainly observed in high value areas,the FSRE is mainly in middle value areas,and the spatial distribution is balanced and staggered.The FULS of the urban construction space and the FSRE are mainly in middle values areas,and the spatial distribution is basically similar.Second,the FULS in the study area is dominated by the single advantage of agricultural production and urban construction,while the FSRE has a relatively balanced distribution of the advantages of ecological protection,single agricultural production and compound advantages of agricultural production and urban construction,and urban construction and ecological protection.The matching between the two is mainly at high and middle levels.Specifically,70%of the province’s land space still has a certain development and utilization potential,and 30%of ULS intensity is close to or exceeds the resource and environment carrying capacity.Third,considering the comprehensive impact of resource endowment,social and economic development and policy and institutional environment on different matching relationships,this paper constructs the land spatial development strategic pattern of“two screens-seven regions-multicore”positioning and“four regions-eight categories”hierarchical area of Shandong at the macro level,and puts forward a differentiated land space development strategy.展开更多
A novel environmental friendly wheat seed coating agent was prepared from the natural polymer,biological pesticide,microfertilizer,microelements and other additives.The laboratory and field test results showed that it...A novel environmental friendly wheat seed coating agent was prepared from the natural polymer,biological pesticide,microfertilizer,microelements and other additives.The laboratory and field test results showed that it could enhance the yield up to 16% and reduce its input cost to 1/6 as compared with the conventional wheat seed coating agent.It is safe without causing any pollution and would have significant economic and environmental benefits.展开更多
The exploitation of coal resources inevitably affects, to different degrees, arable land resources and impacts the socio-economic development in mining areas. Therefore it is of great practical importance to probe the...The exploitation of coal resources inevitably affects, to different degrees, arable land resources and impacts the socio-economic development in mining areas. Therefore it is of great practical importance to probe the rules of the effect from coal resource exploration on arable land. Suitable and effective measures to compensate for damaged to and loss of arable land resources should be taken on the basis of carrying out green mining and reducing damage to limited arable land resources. We have used GIS in simulating the effect of coal resource exploration on arable land. In light of our simulation of the space-time spectrum, the effect is analyzed. Given the socio-economic development conditions of a mining area, specified rational amounts and opportunities for compensation to arable land in mining areas are explored. Finally, from a policy perspective, relevant proposals for rational arable land resource compensation are proposed to facilitate the coordinated development between coal resource exploitation and socio-economy development in mining areas.展开更多
1.Introduction In recent years,China has carried out an extensive preventative battle against air,water,and soil pollution,and the nation’s environmental quality-as reflected by conventional pollutant indicators—has...1.Introduction In recent years,China has carried out an extensive preventative battle against air,water,and soil pollution,and the nation’s environmental quality-as reflected by conventional pollutant indicators—has significantly improved.At the same time,the issue of emerging contaminants(ECs)is beginning to receive increasing attention.ECs generally refer to newly discovered or noticeable pollutants that pose risks to the ecological environment or human health.Either they have not been included in environmental management,or existing management measures are insufficient to effectively prevent and control their risks.The ECs of greatest concern generally include persistent organic pollutants(POPs),endocrine-disrupting chemicals(EDCs),pharmaceuticals and personal care products(PPCPs),and microplastics.These four categories of ECs are not entirely separate,as they interrelate with each other(Fig.1).Chemical production and product usage are the main sources of ECs.China is the world’s largest producer and consumer of bulk chemicals,and the production value of China’s chemical industry is predicted to reach 50%of the global total by 2030[1].Scientific control of ECs based on their environmental risk assessment is a necessary way to support the prevention and legal governance of ECs.展开更多
Through denoting each expert as an agent and viewing a multiple criteria decision-making as a synthesis problem of aggregating experts' ratings, a multi-agent blind model (MABM) is developed for regional eco-enviro...Through denoting each expert as an agent and viewing a multiple criteria decision-making as a synthesis problem of aggregating experts' ratings, a multi-agent blind model (MABM) is developed for regional eco-environmental quality assessment. In this model, the ratings of the evaluated object under an index, given by expert group, are first utilized to construct a series of blind numbers. In general, each index will correspond to different blind numbers. On the basis of aggregating index weights, the rank score in the form of a blind number is obtained for the evaluated object. Then, by means of calculating expected value of the above blind number, its rank score is further converted into a crisp value. By way of comparing the expected value with classification standards, eco-environmental quality of the evaluated sample could he identified successfully in the end. As a case, the MABM is used to evaluate the eco-environmental quality of Chaohu Lake basin. Study result shows that the MABM is a useful model for regional eco-environmental quality assessment.展开更多
Solidification/stabilization (S/S) is one of the most effective methods of dealing with heavy metal contaminated soils. The effects of cyclic wetting and drying on solidified/stabilized contaminated soils were inves...Solidification/stabilization (S/S) is one of the most effective methods of dealing with heavy metal contaminated soils. The effects of cyclic wetting and drying on solidified/stabilized contaminated soils were investigated. A series of test program, unconfined compressive strength (UCS) test, TCLP leaching test and scanning electron microscopy (SEM) test, were performed on lead and zinc contaminated soils solidified/stabilized by fly ash. Test results show that UCS and the leaching characteristics of heavy metal ions of S/S contaminated soils are significantly improved with the increase of fly ash content. UCS of S/S soils firstly increases with the increase of the times of drying and wetting cycles, after reaching the peak, it decreases with it. When the pollutant content is lower (1 000 mg/kg), the TCLP concentration first slightly decreases under cyclic drying and wetting, then increases, but the change is minor. The TCLP concentration is higher under a high pollutant content of 5 000 mg/kg, and increases with the increase of the times of drying and wetting cycles. The results of scanning electron microscopy (SEM) test are consistent with UCS tests and TCLP leaching tests, which reveals the micro-mechanism of the variations of engineering properties of stabilized contaminated soils after drying and wetting cycles.展开更多
Geomechanical parameters are complex and uncertain.In order to take this complexity and uncertainty into account,a probabilistic back-analysis method combining the Bayesian probability with the least squares support v...Geomechanical parameters are complex and uncertain.In order to take this complexity and uncertainty into account,a probabilistic back-analysis method combining the Bayesian probability with the least squares support vector machine(LS-SVM) technique was proposed.The Bayesian probability was used to deal with the uncertainties in the geomechanical parameters,and an LS-SVM was utilized to establish the relationship between the displacement and the geomechanical parameters.The proposed approach was applied to the geomechanical parameter identification in a slope stability case study which was related to the permanent ship lock within the Three Gorges project in China.The results indicate that the proposed method presents the uncertainties in the geomechanical parameters reasonably well,and also improves the understanding that the monitored information is important in real projects.展开更多
In the context of global degradation and loss of natural wetlands,waterbirds have been increasingly using artificial wetlands as alternative habitats.However,waterbirds are facing various threats in these artificial w...In the context of global degradation and loss of natural wetlands,waterbirds have been increasingly using artificial wetlands as alternative habitats.However,waterbirds are facing various threats in these artificial wetlands,due to dramatic environmental changes induced by anthropogenic activities.Exploring the effects of these changes on the temporal dynamics of the waterbird communities can help understand how waterbirds adapt to environmental changes and thus formulate effective management and conservation plans.In this study,we carried out field surveys on waterbirds and environmental factors across 20 subsidence wetlands created by underground coal mining in the Huainan coal mining area in the breeding seasons of 2016 and 2021.We predicted that the waterbird assemblages(i.e.,number of individuals,species richness,Shannon-Wiener diversity,Pielou evenness and species composition) differed between the two years,and that these differences were correlated with the temporal changes in environmental factors.Across the surveyed wetlands,we recorded 26 waterbird species in 2016 and 23 in 2021.For individual wetlands,the number of waterbird individuals and species richness increased by 71.6% and 20.1%,respectively,over the five years,with no changes in Shannon-Wiener diversity and Pielou evenness.The overall increase in the number of bird individuals was mainly caused by an increase in vegetation gleaners and gulls that adapt well to anthropogenic activities.The species composition was significantly different between the two years,which was mainly caused by changes in the number of individuals of dominant species under influence of changes in human activities.For most wetlands,the temporal pairwiseβ-diversities could be explained by species turnover rather than nestedness,probably due to high mobility of waterbird species and dramatic changes in local environments.Our study suggests that waterbird communities could respond to environmental changes in subsidence wetlands,providing important implications for waterbird conservation in human-dominated artificial wetlands.展开更多
Based on Remote Sensing (RS), Geographic Information System (GIS), and combining Principal Component Analysis, this paper designed a numerical integrated evaluation model for mountain eco-environment on the base ...Based on Remote Sensing (RS), Geographic Information System (GIS), and combining Principal Component Analysis, this paper designed a numerical integrated evaluation model for mountain eco-environment on the base of grid scale. Using this model, we evaluated the mountain eco-environmental quality in a case study area-the upper reaches of Minjiang River, and achieved a good result, which accorded well with the real condition. The study indicates that, the integrated evaluation model is suitable for multi-layer spatial factor computation, effectively lowing man's subjective influence in the evaluation process; treating the whole river basin as a system, the model shows full respect to the circulation of material and energy, synthetically embodies the determining impact of such natural condition as water-heat and landform, as well as human interference in natural eco-system; the evaluation result not only clearly presents mountainous vertical distribution features of input factors, but also provides a scientific and reliable thought for quantitatively evaluating mountain eco-environment.展开更多
Bandgap engineering through single-atom site binding on semiconducting photocatalyst can boost the intrinsic activity,selectivity,carrier separation,and electron transport.Here,we report a mixed-valence Ag(0)and Ag(I)...Bandgap engineering through single-atom site binding on semiconducting photocatalyst can boost the intrinsic activity,selectivity,carrier separation,and electron transport.Here,we report a mixed-valence Ag(0)and Ag(I)single atoms co-decorated semiconducting chalcopyrite quantum dots(Ag/CuFeS_(2)QDs)photocatalyst.It demonstrates efficient photocatalytic performances for specific organic dye(rhodamine B,denoted as RhB)as well as inorganic dye(Cr(VI))removal in water under natural sunlight irradiation.The RhB degradation and Cr(VI)removal efficiencies by Ag/CuFeS_(2)QDs were 3.55 and 6.75 times higher than those of the naked CuFeS_(2)QDs at their optimal pH conditions,respectively.Besides,in a mixture of RhB and Cr(VI)solution under neutral condition,the removal ratio has been elevated from 30.2%to 79.4%for Cr(VI),and from 95.2%to 97.3%for RhB degradation by using Ag/CuFeS_(2)QDs after 2 h sunlight illumination.The intrinsic mechanism for the photocatalytic performance improvement is attributed to the narrow bandgap of the single-atomic Ag(I)anchored CuFeS_(2)QDs,which engineers the electronic structure as well as expands the optical light response range.Significantly,the highly active Ag(0)/CuFeS_(2)and Ag(I)/CuFeS_(2)effectively improve the separation efficiency of the carriers,thus enhancing the photocatalytic performances.This work presents a highly efficient single atom/QDs photocatalyst,constructed through bandgap engineering via mixed-valence single noble metal atoms binding on semiconducting QDs.It paves the way for developing high-efficiency single-atom photocatalysts for complex pollutions removal in dyeing wastewater environment.展开更多
Studied the content and distribution of 18 environmental hazardous trace elementsin the lignite, fatty coal, anthracite and its burnt products by combustion simulatingexpriment in the one-dismensinal boiler.The transf...Studied the content and distribution of 18 environmental hazardous trace elementsin the lignite, fatty coal, anthracite and its burnt products by combustion simulatingexpriment in the one-dismensinal boiler.The transformations and concentration of 18 traceelements during different coal combustion were discussed.The results show that there aresome content distribution of 18 hazardous trace elements in every burnt product, but thelaw of concentration and dispersion of every trace element during different coal combustionis very different.Experiment results indicate that the transformation and concentrationof trace elements during coal combustion are related to the element contents and occur-rencesof trace elements in raw coal, but are also affected by some man-made factorssuch as the combustion method of boiler, combustion temperature and atmosphere, thetype of precipitators and so on.展开更多
This novel environmentally friendly wheat seed coating agent which has been made with natural polymer as the primary material could increase yield by about 9% compared with the conventionally virulent wheat seed coati...This novel environmentally friendly wheat seed coating agent which has been made with natural polymer as the primary material could increase yield by about 9% compared with the conventionally virulent wheat seed coating agent. In the premise of this production, the content of malondialdehyde (MDA) and peroxidase (POD) was determined. The results show that, after treated by the self-made wheat seed coating agent, the contents of the MDA were less than traditional group and the blank control group and POD contents were higher than traditional group and blank control group, this provides a good foundation on the further research of self-control wheat seed coating agent.展开更多
This paper analyzed the total factor productivity of Shandong Province and its impact on the local economic environment through Malmquist-Luenberger productivity index. The results of the paper were included as follow...This paper analyzed the total factor productivity of Shandong Province and its impact on the local economic environment through Malmquist-Luenberger productivity index. The results of the paper were included as follows. Without consideration of the environmental constraints, Index M of the total factor productivity of Shandong Province from high to low was Heze, Jinan, Qingdao, Weihai, Dongying, Zaozhuang, Jining, Tai'an, Dezhou, Liaocheng, Yantai, Zibo, Weifang, Linyi, Binzhou, Rizhao, Laiwu, among which Index M of Linyi, Binzhou, Rizhao, Laiwuwere were less than 1; taking the environmental constraints into account, Index ML of the total factor productivity of Shandong Province was reduced, from high to low was Jinan, Qingdao, Weihai, Yantai, Heze, Liaocheng, Tai'an, Weifang, Jining, Linyi, Zibo, Dongying, Zaozhuang, Rizhao, Laiwu, Binzhou, Dezhou, among which Index ML of 9 cities behind Jining were less than 1. In terms of the development mode, Jinan, Qingdao, Tai'an, Weihai, Jining and Heze were resource-conserving and environment-friendly cities; Dongying and Zaozhuang were resourceconserving and environment-polluted cities; Liaocheng, Linyi, Weifang and Yantai were resource-wasted and environment-friendly cities; Binzhou, Dezhou, Laiwu, Rizhao and Zibo were resource-wasted and environment-pol uted cities.展开更多
Coal-based soild wastes(CBSWs)are industrial byproducts that can be harmful to the environment.The exploitation and utilization of CBsWs offer societal advantages such as resource conservation,pollution reduction,and ...Coal-based soild wastes(CBSWs)are industrial byproducts that can be harmful to the environment.The exploitation and utilization of CBsWs offer societal advantages such as resource conservation,pollution reduction,and cost-effective production.However,environmentally sustainable management remains a worldwide challenge due to the substantial production volume and limited disposal capacity of CBSWs.The physicochemical properties and utilization of CBSWs are summarized,including fly ash,coal gangue and coal gasification slag.It also presents the current global applications status of CBSWs resources and examines market supply and demand.Subsequently,the paper provides an overview of studies on ways to utilise CBSWs,highlighting the primary avenues of CBSWs resource utilization which are mainly from the fields of chemical materials,metallurgy and agriculture.Furthermore,a comparative evaluation of the various methods for CBSWs resource recovery is conducted,outlining their respective advantages and disadvantages.The future development of CBSWs recycling processes is also discussed.The review concludes that while there is a growing need for attention in CBSWs recycling,its utilization will involve a combination of both large-scale treatment and refinement processes.The paper aims to offer references and insights for the effective utilization and environmental protection of CBSWs.Future direction will focus on the collaborative utilization of CBSWs,emphasizing on the combination of large-scale and high-value utilization.In addition,there is a need to establish a comprehensive database based on on-site production practices,explore on-site solutions to reduce transportation costs,and improve physicochemical properties during the production process.展开更多
The presence of heavy metals in soil negatively impacts its mechanical properties.Reactive MgO carbonation presents a promising approach to enhance the solidification of Pb-contaminated sandy soils.However,the mechani...The presence of heavy metals in soil negatively impacts its mechanical properties.Reactive MgO carbonation presents a promising approach to enhance the solidification of Pb-contaminated sandy soils.However,the mechanical properties and structural behavior of contaminated soils during carbonation can vary significantly due to differences in soil composition.This study examines the potential application and underlying mechanisms of reactive MgO carbonation in improving the mechanical properties of Pb-contaminated red clay.The findings demonstrate that Pb-contaminated red clay transitions from a plastic to a brittle state following reactive MgO carbonation.After 1 h of treatment,the strength of the red clay exceeded 3 MPa,even at high Pb^(2+)concentrations.The deformation modulus to unconfined compressive strength(UCS)ratio was calculated to be 37.761,with the failure strain primarily ranging from 1.5%to 4.0%.A strength prediction model for the reactive MgO-stabilized Pb-contaminated red clay was proposed,which showed good predictive accuracy.Furthermore,reactive MgO carbonation significantly reduced the Pb leaching concentration in the high-level Pb-contaminated soil to below 0.1 mg/L.Microscopic analysis revealed that an optimal amount of hydrated magnesium carbonates(HMCs)formed a stable and compact structure with the soil particles.However,long-term carbonation causes red clay particles to become sandy,and excessive HMCs can harm the soil structure.Therefore,to maximize the strength improvement while avoiding structural damage,the carbonation time should be controlled to 1 h.展开更多
文摘Traditional polymeric photocatalysts are typically constructed using aromatic building blocks to enhanceπ-conjugation.However,their inherent hydrophobicity and rigid structure lead to poor dispersibility in aqueous solutions,resulting in significant optical losses and exciton recombination.In this study,two series of six novel polymer photocatalysts(FLUSO,FLUSO-PEG10,FLUSO-PEG30;CPDTSO,CPDTSO-PEG10,CPDTSO-PEG30)are designed and synthesized by incorporating the hydrophilic,non-conjugated polyethylene glycol(PEG)chain,into both the main and side chains of polymers.By precisely optimizing the ratio of hydrophilic PEG segments,the water dispersibility is significantly improved while the light absorption capability of the polymer photocatalysts is well maintained.The experimental results confirm that the optimized FLUSO-PEG10 exhibits excellent photocatalytic hydrogen evolution rate,reaching up to 33.9 mmol/(g·h),which is nearly three times higher than that of fullyπ-conjugated counterparts.Water contact angles and particle size analyses reveal that incorporating non-conjugated segments into the main chains enhances the capacitance of the polymer/water interface and reduces particle aggregation,leading to improved photocatalyst dispersion and enhanced charge generation.
基金funded by the Major Humanities and Social Sciences Research Projects in Zhejiang Higher Education Institutions,grant number 2023QN131National Innovation Training Program Project in China,grant number 202410451009.
文摘Considering the special features of dynamic environment economic dispatch of power systems with high dimensionality,strong coupling,nonlinearity,and non-convexity,a GA-DE multi-objective optimization algorithm based on dual-population pseudo-parallel genetic algorithm-differential evolution is proposed in this paper.The algorithm is based on external elite archive and Pareto dominance,and it adopts the cooperative co-evolution mechanism of differential evolution and genetic algorithm.Average entropy and cubic chaoticmapping initialization strategies are proposed to increase population diversity.In the proposed method,we analyze the distribution of neighboring solutions and apply a new Pareto solution set pruning approach.Unlike traditional models,this work takes the transmission losses as an optimization target and overcomes complex model constraints through a dynamic relaxation constraint approach.To solve the uncertainty caused by integrating wind and photovoltaic energy in power system scheduling,a multi-objective dynamic environment economical dispatch model is set up that takes the system spinning reserve and network highest losses into account.In this paper,the DE algorithm is improved to form the DGAGE algorithm for the objective optimization of the overall power system,The DE algorithm part of DGAGE is combined with the JAYA algorithm to form the system scheduling HDJ algorithm for multiple energy sources connected to the grid.The effectiveness of the proposed method is demonstrated using CEC2022 and CEC2005 test functions,showing robust optimization performance.Validation on a classical 10-unit system confirms the feasibility of the proposed algorithm in addressing power system scheduling issues.This approach provides a novel solution for dynamic power dispatch systems.
基金the support from the National Key Research and Development Program of China (No. 2022YFC2904504)the Science and Technology Research Project of Jiangxi Provincial Department of Education, China (No. GJJ2200864)the Gansu Provincial Key Research and Development Project, China (No. 22YF7GA073)。
文摘The flotation separation of argentite from sphalerite using ammonium dibutyl dithiophosphate(ADD)was studied.Molecular simulation(MS)calculation shows that ADD is chemisorbed on argentite and sphalerite surface in the form of S—P bond.The ADD adsorption on argentite and sphalerite surface in Ag^(+)system was revealed by ICP,Zeta potential and XPS analyses.It is shown that the dissolved Ag^(+)from argentite surface can be absorbed on sphalerite surface in the form of silver hydroxide,and AgOH hydrophilic colloid prevents the adsorption of ADD on sphalerite surface.The ADD adsorption on argentite and sphalerite surface in the pulp containing silver and zinc ions was revealed by adsorption capacity and surface wettability analyses.It is shown that the combined Zn(OH)_(2) and AgOH hydrophilic colloid leads to greater ADD adsorption capacity on argentite surface and stronger surface hydrophobicity than sphalerite.Flotation tests demonstrate that ADD enables efficient separation of argentite from sphalerite in the pulp containing silver and zinc ions.
基金supported by the Central Government Guiding Local Science and Technology Development Fund Project(No.2024SZY0343)the Joint Research Program for Ecological Conservation and High Quality Development of the Yellow River Basin(No.2022-YRUC-01-050205)+2 种基金the Higher Education Scientific Research Project of Inner Mongolia Autonomous Region(No.NJZZ23078)the project of Inner Mongolia"Prairie Talents"Engineering Innovation Entrepreneurship Talent Team,the Major Projects of Erdos Science and Technology(No.2022EEDSKJZDZX015)the Innovation Team of the Inner Mongolia Academy of Science and Technology(No.CXTD2023-01-016).
文摘Rural domestic sewage treatment is critical for environmental protection.This study defines the spatial pattern of villages from the perspective of rural sewage treatment and develops an integrated decision-making system to propose a sewage treatment mode and scheme suitable for local conditions.By considering the village spatial layout and terrain factors,a decision tree model of residential density and terrain type was constructed with accuracies of 76.47%and 96.00%,respectively.Combined with binary classification probability unit regression,an appropriate sewage treatment mode for the village was determined with 87.00%accuracy.The Analytic Hierarchy Process(AHP),combined with the Technique for Order Preference(TOPSIS)by Similarity to an Ideal Solution model,formed the basis for optimal treatment process selection under different emission standards.Verification was conducted in 542 villages across three counties of the Inner Mongolia Autonomous Region,focusing on the standard effluent effect(0.3773),low investment cost(0.3196),and high standard effluent effect(0.5115)to determine the best treatment process for the same emission standard under different needs.The annual environmental and carbon emission benefits of sewage treatment in these villages were estimated.This model matches village density,geographic feature,and social development level,and provides scientific support and a theoretical basis for rural sewage treatment decision-making.
基金financially supported by the National Natural Science Foundation of China(Grant Nos.41962009,41772197)the Innovation Fund of East China University of Technology(Grant No.DHYC202007)。
文摘Tafoni are a type of cavernous weathering features widespread in different climate zones around the world,but their origin has not been fully understood.Little attention was paid on tafoni in conglomerates.Danxiashan UNESCO Global Geopark,located within the subtropic humid region of South China,has a landscape of large tafoni that occur on cliffs of red conglomerates.Both the Dinosaur Rock and Pagoda Peak of the geopark were selected to investigate the formation mechanisms of tafoni in conglomerates.During the field investigation,the size,rock hardness,and the external and internal meteorology of tafoni were measured and tested.The texture and composition of rock samples were observed,and the ion chromatography experiments were performed as well.Results show that tafoni have well ellipsoidal openings.Clasts of the conglomerates are largely sub-rounded and poorly sorted,and the cement is dominantly composed of calcite and iron oxide.The hardness of the lips is almost equal to that of the columns,and both are slightly higher than the backwalls.Compared with the external intense environmental changes,the interior of the tafoni is characterized by smaller temperature and relative humidity ranges and windless condition.Therefore,the porous and permeable conglomerates provide favorable lithology for tafoni development,and the micro-environment within the caverns is conducive to improving water utilization efficiency and enhancing salt weathering.The salts mainly consist of sulfates and nitrates,which might be derived from frequent raining,water evaporation and red beds as well.Consequently,tafoni are the result of the synergistic effects by multiple factors,rather than a single mechanism.
基金National Natural Science Foundation of China,No.42077434,No.41771560Shandong Provincial Institutions of Higher Learning“Youth Innovation Team Development Plan”Project,No.2019RWG016。
文摘Based on the carrying capacity of the resources and the environment,this article defines the connotation of the land multifunctional space(LMFS)from three aspects,ecological protection,agricultural production and urban construction,in the new era of land space planning system.Moreover,a framework is constructed for the coordinated development of the multi-functional oriented space to match the use of land space(ULS)with the supply of resources and environment(SRE).Based on this,the technology and methods of comprehensive evaluation,dominance recognition,and matching relationship division functions of the use of land space(FULS)and functions of the supply of resources and environment(FSRE)are discussed.The advantageous functions of the use of land space(AFULS)and advantageous functions of the supply of resources and environment(AFSRE)are also identified in the study area.A LMFS coordinated development system integrating“function position-comprehensive partition-regulation strategy”is proposed.Through the empirical study of Shandong province,we found that,first,the FULS of ecological protection space in the province is mainly found in high value areas,and the FSRE is mainly in low value areas,which has certain complementarity in the space.The FULS of agricultural production space is mainly observed in high value areas,the FSRE is mainly in middle value areas,and the spatial distribution is balanced and staggered.The FULS of the urban construction space and the FSRE are mainly in middle values areas,and the spatial distribution is basically similar.Second,the FULS in the study area is dominated by the single advantage of agricultural production and urban construction,while the FSRE has a relatively balanced distribution of the advantages of ecological protection,single agricultural production and compound advantages of agricultural production and urban construction,and urban construction and ecological protection.The matching between the two is mainly at high and middle levels.Specifically,70%of the province’s land space still has a certain development and utilization potential,and 30%of ULS intensity is close to or exceeds the resource and environment carrying capacity.Third,considering the comprehensive impact of resource endowment,social and economic development and policy and institutional environment on different matching relationships,this paper constructs the land spatial development strategic pattern of“two screens-seven regions-multicore”positioning and“four regions-eight categories”hierarchical area of Shandong at the macro level,and puts forward a differentiated land space development strategy.
基金supported by the Scientific and Tech-nological Project of Zhejiang Province,China (ZK-20061103)
文摘A novel environmental friendly wheat seed coating agent was prepared from the natural polymer,biological pesticide,microfertilizer,microelements and other additives.The laboratory and field test results showed that it could enhance the yield up to 16% and reduce its input cost to 1/6 as compared with the conventional wheat seed coating agent.It is safe without causing any pollution and would have significant economic and environmental benefits.
基金Project 50774080 supported by the National Natural Science Foundation of China
文摘The exploitation of coal resources inevitably affects, to different degrees, arable land resources and impacts the socio-economic development in mining areas. Therefore it is of great practical importance to probe the rules of the effect from coal resource exploration on arable land. Suitable and effective measures to compensate for damaged to and loss of arable land resources should be taken on the basis of carrying out green mining and reducing damage to limited arable land resources. We have used GIS in simulating the effect of coal resource exploration on arable land. In light of our simulation of the space-time spectrum, the effect is analyzed. Given the socio-economic development conditions of a mining area, specified rational amounts and opportunities for compensation to arable land in mining areas are explored. Finally, from a policy perspective, relevant proposals for rational arable land resource compensation are proposed to facilitate the coordinated development between coal resource exploitation and socio-economy development in mining areas.
基金supported by the Major Project of National Natural Science Foundation of China(52091544).
文摘1.Introduction In recent years,China has carried out an extensive preventative battle against air,water,and soil pollution,and the nation’s environmental quality-as reflected by conventional pollutant indicators—has significantly improved.At the same time,the issue of emerging contaminants(ECs)is beginning to receive increasing attention.ECs generally refer to newly discovered or noticeable pollutants that pose risks to the ecological environment or human health.Either they have not been included in environmental management,or existing management measures are insufficient to effectively prevent and control their risks.The ECs of greatest concern generally include persistent organic pollutants(POPs),endocrine-disrupting chemicals(EDCs),pharmaceuticals and personal care products(PPCPs),and microplastics.These four categories of ECs are not entirely separate,as they interrelate with each other(Fig.1).Chemical production and product usage are the main sources of ECs.China is the world’s largest producer and consumer of bulk chemicals,and the production value of China’s chemical industry is predicted to reach 50%of the global total by 2030[1].Scientific control of ECs based on their environmental risk assessment is a necessary way to support the prevention and legal governance of ECs.
基金Under the auspices of the Natural Science Foundation of Anhui Province (No. 050450303 )
文摘Through denoting each expert as an agent and viewing a multiple criteria decision-making as a synthesis problem of aggregating experts' ratings, a multi-agent blind model (MABM) is developed for regional eco-environmental quality assessment. In this model, the ratings of the evaluated object under an index, given by expert group, are first utilized to construct a series of blind numbers. In general, each index will correspond to different blind numbers. On the basis of aggregating index weights, the rank score in the form of a blind number is obtained for the evaluated object. Then, by means of calculating expected value of the above blind number, its rank score is further converted into a crisp value. By way of comparing the expected value with classification standards, eco-environmental quality of the evaluated sample could he identified successfully in the end. As a case, the MABM is used to evaluate the eco-environmental quality of Chaohu Lake basin. Study result shows that the MABM is a useful model for regional eco-environmental quality assessment.
基金Foundation item: Projects(41172273, 40802079, 51108288) supported by the National Natural Science Foundation of China Project(KLE-TJGE-B1106) supported by the Opening Fund of Key Laboratory of Geotechnical and Underground Engineering of Ministry of Education (Tongji University), China
文摘Solidification/stabilization (S/S) is one of the most effective methods of dealing with heavy metal contaminated soils. The effects of cyclic wetting and drying on solidified/stabilized contaminated soils were investigated. A series of test program, unconfined compressive strength (UCS) test, TCLP leaching test and scanning electron microscopy (SEM) test, were performed on lead and zinc contaminated soils solidified/stabilized by fly ash. Test results show that UCS and the leaching characteristics of heavy metal ions of S/S contaminated soils are significantly improved with the increase of fly ash content. UCS of S/S soils firstly increases with the increase of the times of drying and wetting cycles, after reaching the peak, it decreases with it. When the pollutant content is lower (1 000 mg/kg), the TCLP concentration first slightly decreases under cyclic drying and wetting, then increases, but the change is minor. The TCLP concentration is higher under a high pollutant content of 5 000 mg/kg, and increases with the increase of the times of drying and wetting cycles. The results of scanning electron microscopy (SEM) test are consistent with UCS tests and TCLP leaching tests, which reveals the micro-mechanism of the variations of engineering properties of stabilized contaminated soils after drying and wetting cycles.
基金Projects(2013BAB02B01,2013BAB02B03)supported by the National Key Technologies R&D Program of ChinaProjects(41072224,41272347)supported by the National Natural Science Foundation of China
文摘Geomechanical parameters are complex and uncertain.In order to take this complexity and uncertainty into account,a probabilistic back-analysis method combining the Bayesian probability with the least squares support vector machine(LS-SVM) technique was proposed.The Bayesian probability was used to deal with the uncertainties in the geomechanical parameters,and an LS-SVM was utilized to establish the relationship between the displacement and the geomechanical parameters.The proposed approach was applied to the geomechanical parameter identification in a slope stability case study which was related to the permanent ship lock within the Three Gorges project in China.The results indicate that the proposed method presents the uncertainties in the geomechanical parameters reasonably well,and also improves the understanding that the monitored information is important in real projects.
基金the National Natural Science Foundation of China(grant 31970500 and 31770571)the Excellent Youth Project of the Anhui Natural Science Foundation(grant 2108085Y09)。
文摘In the context of global degradation and loss of natural wetlands,waterbirds have been increasingly using artificial wetlands as alternative habitats.However,waterbirds are facing various threats in these artificial wetlands,due to dramatic environmental changes induced by anthropogenic activities.Exploring the effects of these changes on the temporal dynamics of the waterbird communities can help understand how waterbirds adapt to environmental changes and thus formulate effective management and conservation plans.In this study,we carried out field surveys on waterbirds and environmental factors across 20 subsidence wetlands created by underground coal mining in the Huainan coal mining area in the breeding seasons of 2016 and 2021.We predicted that the waterbird assemblages(i.e.,number of individuals,species richness,Shannon-Wiener diversity,Pielou evenness and species composition) differed between the two years,and that these differences were correlated with the temporal changes in environmental factors.Across the surveyed wetlands,we recorded 26 waterbird species in 2016 and 23 in 2021.For individual wetlands,the number of waterbird individuals and species richness increased by 71.6% and 20.1%,respectively,over the five years,with no changes in Shannon-Wiener diversity and Pielou evenness.The overall increase in the number of bird individuals was mainly caused by an increase in vegetation gleaners and gulls that adapt well to anthropogenic activities.The species composition was significantly different between the two years,which was mainly caused by changes in the number of individuals of dominant species under influence of changes in human activities.For most wetlands,the temporal pairwiseβ-diversities could be explained by species turnover rather than nestedness,probably due to high mobility of waterbird species and dramatic changes in local environments.Our study suggests that waterbird communities could respond to environmental changes in subsidence wetlands,providing important implications for waterbird conservation in human-dominated artificial wetlands.
文摘Based on Remote Sensing (RS), Geographic Information System (GIS), and combining Principal Component Analysis, this paper designed a numerical integrated evaluation model for mountain eco-environment on the base of grid scale. Using this model, we evaluated the mountain eco-environmental quality in a case study area-the upper reaches of Minjiang River, and achieved a good result, which accorded well with the real condition. The study indicates that, the integrated evaluation model is suitable for multi-layer spatial factor computation, effectively lowing man's subjective influence in the evaluation process; treating the whole river basin as a system, the model shows full respect to the circulation of material and energy, synthetically embodies the determining impact of such natural condition as water-heat and landform, as well as human interference in natural eco-system; the evaluation result not only clearly presents mountainous vertical distribution features of input factors, but also provides a scientific and reliable thought for quantitatively evaluating mountain eco-environment.
基金financially supported by the National Natural Science Foundation of China(Nos.21777045,61875119)Distinguished Young Scholar Fund from Natural Science Funds of Guangdong Province,China(No.2020B151502094)+1 种基金the program for Professor of Special Appointment(Eastern Scholar)at Shanghai Institutions of Higher Learning,Shanghai Rising-Star Program(No.19QA1404000)Shanghai Talent Development Fund.
文摘Bandgap engineering through single-atom site binding on semiconducting photocatalyst can boost the intrinsic activity,selectivity,carrier separation,and electron transport.Here,we report a mixed-valence Ag(0)and Ag(I)single atoms co-decorated semiconducting chalcopyrite quantum dots(Ag/CuFeS_(2)QDs)photocatalyst.It demonstrates efficient photocatalytic performances for specific organic dye(rhodamine B,denoted as RhB)as well as inorganic dye(Cr(VI))removal in water under natural sunlight irradiation.The RhB degradation and Cr(VI)removal efficiencies by Ag/CuFeS_(2)QDs were 3.55 and 6.75 times higher than those of the naked CuFeS_(2)QDs at their optimal pH conditions,respectively.Besides,in a mixture of RhB and Cr(VI)solution under neutral condition,the removal ratio has been elevated from 30.2%to 79.4%for Cr(VI),and from 95.2%to 97.3%for RhB degradation by using Ag/CuFeS_(2)QDs after 2 h sunlight illumination.The intrinsic mechanism for the photocatalytic performance improvement is attributed to the narrow bandgap of the single-atomic Ag(I)anchored CuFeS_(2)QDs,which engineers the electronic structure as well as expands the optical light response range.Significantly,the highly active Ag(0)/CuFeS_(2)and Ag(I)/CuFeS_(2)effectively improve the separation efficiency of the carriers,thus enhancing the photocatalytic performances.This work presents a highly efficient single atom/QDs photocatalyst,constructed through bandgap engineering via mixed-valence single noble metal atoms binding on semiconducting QDs.It paves the way for developing high-efficiency single-atom photocatalysts for complex pollutions removal in dyeing wastewater environment.
基金Supported by the National Natural Science Key Foundation of China(40133010)Natural Science Foundation of China of Anhui University of Science and Technology for ph.D to Research(DG414)
文摘Studied the content and distribution of 18 environmental hazardous trace elementsin the lignite, fatty coal, anthracite and its burnt products by combustion simulatingexpriment in the one-dismensinal boiler.The transformations and concentration of 18 traceelements during different coal combustion were discussed.The results show that there aresome content distribution of 18 hazardous trace elements in every burnt product, but thelaw of concentration and dispersion of every trace element during different coal combustionis very different.Experiment results indicate that the transformation and concentrationof trace elements during coal combustion are related to the element contents and occur-rencesof trace elements in raw coal, but are also affected by some man-made factorssuch as the combustion method of boiler, combustion temperature and atmosphere, thetype of precipitators and so on.
文摘This novel environmentally friendly wheat seed coating agent which has been made with natural polymer as the primary material could increase yield by about 9% compared with the conventionally virulent wheat seed coating agent. In the premise of this production, the content of malondialdehyde (MDA) and peroxidase (POD) was determined. The results show that, after treated by the self-made wheat seed coating agent, the contents of the MDA were less than traditional group and the blank control group and POD contents were higher than traditional group and blank control group, this provides a good foundation on the further research of self-control wheat seed coating agent.
基金Sponsored by Key Research and Development Project of Shandong Province(2016GSF117021)Research Development Program of Colleges and Universities in Shandong Province(J15LD04)Scientific Research Project for Statistics of Shandong Province(2014YBXM210)
文摘This paper analyzed the total factor productivity of Shandong Province and its impact on the local economic environment through Malmquist-Luenberger productivity index. The results of the paper were included as follows. Without consideration of the environmental constraints, Index M of the total factor productivity of Shandong Province from high to low was Heze, Jinan, Qingdao, Weihai, Dongying, Zaozhuang, Jining, Tai'an, Dezhou, Liaocheng, Yantai, Zibo, Weifang, Linyi, Binzhou, Rizhao, Laiwu, among which Index M of Linyi, Binzhou, Rizhao, Laiwuwere were less than 1; taking the environmental constraints into account, Index ML of the total factor productivity of Shandong Province was reduced, from high to low was Jinan, Qingdao, Weihai, Yantai, Heze, Liaocheng, Tai'an, Weifang, Jining, Linyi, Zibo, Dongying, Zaozhuang, Rizhao, Laiwu, Binzhou, Dezhou, among which Index ML of 9 cities behind Jining were less than 1. In terms of the development mode, Jinan, Qingdao, Tai'an, Weihai, Jining and Heze were resource-conserving and environment-friendly cities; Dongying and Zaozhuang were resourceconserving and environment-polluted cities; Liaocheng, Linyi, Weifang and Yantai were resource-wasted and environment-friendly cities; Binzhou, Dezhou, Laiwu, Rizhao and Zibo were resource-wasted and environment-pol uted cities.
基金supported by the following:“National Natural Science Foundation of China”(22478231)“Natural Science Foundation of Henan”(242300421449)“Fundamental Research Program of Shanxi Province”(202403021221011).
文摘Coal-based soild wastes(CBSWs)are industrial byproducts that can be harmful to the environment.The exploitation and utilization of CBsWs offer societal advantages such as resource conservation,pollution reduction,and cost-effective production.However,environmentally sustainable management remains a worldwide challenge due to the substantial production volume and limited disposal capacity of CBSWs.The physicochemical properties and utilization of CBSWs are summarized,including fly ash,coal gangue and coal gasification slag.It also presents the current global applications status of CBSWs resources and examines market supply and demand.Subsequently,the paper provides an overview of studies on ways to utilise CBSWs,highlighting the primary avenues of CBSWs resource utilization which are mainly from the fields of chemical materials,metallurgy and agriculture.Furthermore,a comparative evaluation of the various methods for CBSWs resource recovery is conducted,outlining their respective advantages and disadvantages.The future development of CBSWs recycling processes is also discussed.The review concludes that while there is a growing need for attention in CBSWs recycling,its utilization will involve a combination of both large-scale treatment and refinement processes.The paper aims to offer references and insights for the effective utilization and environmental protection of CBSWs.Future direction will focus on the collaborative utilization of CBSWs,emphasizing on the combination of large-scale and high-value utilization.In addition,there is a need to establish a comprehensive database based on on-site production practices,explore on-site solutions to reduce transportation costs,and improve physicochemical properties during the production process.
基金supported by the National Key Research and Development Program of China(Grant No.2023YFC3707900)the National Natural Science Foundation of China(Grant Nos.42030710 and 42472337).
文摘The presence of heavy metals in soil negatively impacts its mechanical properties.Reactive MgO carbonation presents a promising approach to enhance the solidification of Pb-contaminated sandy soils.However,the mechanical properties and structural behavior of contaminated soils during carbonation can vary significantly due to differences in soil composition.This study examines the potential application and underlying mechanisms of reactive MgO carbonation in improving the mechanical properties of Pb-contaminated red clay.The findings demonstrate that Pb-contaminated red clay transitions from a plastic to a brittle state following reactive MgO carbonation.After 1 h of treatment,the strength of the red clay exceeded 3 MPa,even at high Pb^(2+)concentrations.The deformation modulus to unconfined compressive strength(UCS)ratio was calculated to be 37.761,with the failure strain primarily ranging from 1.5%to 4.0%.A strength prediction model for the reactive MgO-stabilized Pb-contaminated red clay was proposed,which showed good predictive accuracy.Furthermore,reactive MgO carbonation significantly reduced the Pb leaching concentration in the high-level Pb-contaminated soil to below 0.1 mg/L.Microscopic analysis revealed that an optimal amount of hydrated magnesium carbonates(HMCs)formed a stable and compact structure with the soil particles.However,long-term carbonation causes red clay particles to become sandy,and excessive HMCs can harm the soil structure.Therefore,to maximize the strength improvement while avoiding structural damage,the carbonation time should be controlled to 1 h.