The technology for green and macro-conversion of solid waste biomass to prepare high-quality activated carbon demands urgent development.This study proposes a technique for synthesizing carbon adsorbents using trace K...The technology for green and macro-conversion of solid waste biomass to prepare high-quality activated carbon demands urgent development.This study proposes a technique for synthesizing carbon adsorbents using trace KOH-catalyzed CO_(2) activation.Comprehensive investigations were conducted on three aspects:physicochemical structure evolution of biochar,mechanistic understanding of trace KOH-facilitated CO_(2) activation processes,and application characteristics for CO_(2) adsorption.Results demonstrate that biochar activated by trace KOH(<10%)and CO_(2) achieves comparable specific surface area(1244.09 m^(2)/g)to that obtained with 100%KOH activation(1425.10 m^(2)/g).The pore structure characteristics(specific surface area and pore volume)are governed by CO and CH4 generated through K-salt catalyzed reactions between CO_(2) and biochar.The optimal CO_(2) adsorption capacities of KBC adsorbent reached 4.70 mmol/g(0℃)and 7.25 mmol/g(25℃),representing the maximum values among comparable carbon adsorbents.The 5%KBC-CO_(2) sample exhibited CO_(2) adsorption capacities of 3.19 and 5.01 mmol/g under respective conditions,attaining current average performance levels.Notably,CO_(2)/N_(2) selectivity(85∶15,volume ratio)reached 64.71 at 0.02 bar with robust cycling stability.Molecular dynamics simulations revealed that oxygen-containing functional groups accelerate CO_(2) adsorption kinetics and enhance micropore storage capacity.This technical route offers simplicity,environmental compatibility,and scalability,providing critical references for large-scale preparation of high-quality carbon materials.展开更多
Although the Technique for Order Preference by Similarity to Ideal Solution(TOPSIS)model has been widely applied in water quality assessment by numerous studies,several common limitations remain unresolved.Specificall...Although the Technique for Order Preference by Similarity to Ideal Solution(TOPSIS)model has been widely applied in water quality assessment by numerous studies,several common limitations remain unresolved.Specifically:1)Subjective elements in methods such as fuzzy theory and the analytic hierarchy process(AHP)may distort evaluation outcomes;2)The utilization of raw sample data is in‐sufficient when constructing evaluation matrices;3)The traditional entropy weight method in TOPSIS merely reflects statistical character‐istics of the final matrix while neglecting richer information embedded in raw datasets.To address these issues,we proximate probability distribution function of various indicators by using cubic spline interpolation and fully exploit information in the existing massive sample data.In this paper,the entropy weight method is enhanced based on the concept mentioned above and integrated with TOPSIS model to construct a novel evaluation model.Furthermore,the experimental analysis using wastewater monitoring data from Guizhou Province,China,verifies its practicality,and its results provide valuable references for local water environmental management.展开更多
基金supported by the National Natural Science Foundation of China(52376103,542B2081).
文摘The technology for green and macro-conversion of solid waste biomass to prepare high-quality activated carbon demands urgent development.This study proposes a technique for synthesizing carbon adsorbents using trace KOH-catalyzed CO_(2) activation.Comprehensive investigations were conducted on three aspects:physicochemical structure evolution of biochar,mechanistic understanding of trace KOH-facilitated CO_(2) activation processes,and application characteristics for CO_(2) adsorption.Results demonstrate that biochar activated by trace KOH(<10%)and CO_(2) achieves comparable specific surface area(1244.09 m^(2)/g)to that obtained with 100%KOH activation(1425.10 m^(2)/g).The pore structure characteristics(specific surface area and pore volume)are governed by CO and CH4 generated through K-salt catalyzed reactions between CO_(2) and biochar.The optimal CO_(2) adsorption capacities of KBC adsorbent reached 4.70 mmol/g(0℃)and 7.25 mmol/g(25℃),representing the maximum values among comparable carbon adsorbents.The 5%KBC-CO_(2) sample exhibited CO_(2) adsorption capacities of 3.19 and 5.01 mmol/g under respective conditions,attaining current average performance levels.Notably,CO_(2)/N_(2) selectivity(85∶15,volume ratio)reached 64.71 at 0.02 bar with robust cycling stability.Molecular dynamics simulations revealed that oxygen-containing functional groups accelerate CO_(2) adsorption kinetics and enhance micropore storage capacity.This technical route offers simplicity,environmental compatibility,and scalability,providing critical references for large-scale preparation of high-quality carbon materials.
文摘Although the Technique for Order Preference by Similarity to Ideal Solution(TOPSIS)model has been widely applied in water quality assessment by numerous studies,several common limitations remain unresolved.Specifically:1)Subjective elements in methods such as fuzzy theory and the analytic hierarchy process(AHP)may distort evaluation outcomes;2)The utilization of raw sample data is in‐sufficient when constructing evaluation matrices;3)The traditional entropy weight method in TOPSIS merely reflects statistical character‐istics of the final matrix while neglecting richer information embedded in raw datasets.To address these issues,we proximate probability distribution function of various indicators by using cubic spline interpolation and fully exploit information in the existing massive sample data.In this paper,the entropy weight method is enhanced based on the concept mentioned above and integrated with TOPSIS model to construct a novel evaluation model.Furthermore,the experimental analysis using wastewater monitoring data from Guizhou Province,China,verifies its practicality,and its results provide valuable references for local water environmental management.
