The fly ash from waste incineration poses a serious threat to human health due to its high content of dioxins.Hydrothermal treatment is an efficient and clean method on the decomposition and detoxifying of fly ash.To ...The fly ash from waste incineration poses a serious threat to human health due to its high content of dioxins.Hydrothermal treatment is an efficient and clean method on the decomposition and detoxifying of fly ash.To study the degradation mechanism of dioxins,this paper uses molecular dynamics(MD)to simulate the hydrothermal reaction process of polychlorinated dibenzo-p-dioxins(PCDDs)under different conditions,and the degradation mechanism of PCDDs is obtained.The results show that the degradation of PCDDs includes two pathways:the first pathway is the substitution of Cl groups by hydroxyl groups to form low-chlorine substitution products through direct hydrogenation,and the second pathway is the formation of non-toxic benzene ring structures accompanied by the cleavage of C—O bonds.The two degradation pathways of PCDDs well explain the changes in toxicity before and after the hydrothermal treatment of fly ash,which is consistent with experimental results.This study provides theoretical guidance for the harmless treatment process of fly ash via hydrothermal method.展开更多
Microplastics(MPs)are of particular concern due to their ubiquitous occurrence and propensity to interact and concentrate various waterborne contaminants from aqueous surroundings.Studies on the interaction and joint ...Microplastics(MPs)are of particular concern due to their ubiquitous occurrence and propensity to interact and concentrate various waterborne contaminants from aqueous surroundings.Studies on the interaction and joint toxicity of MPs on engineered nanoparticles(ENPs)are exhaustive,but limited research on the effect of MPs on the properties of ENPs in multisolute systems.Here,the effect of MPs on adsorption ability of ENPs to antibiotics was investigated for the first time.The results demonstrated that MPs enhanced the adsorption affinity of ENPs to antibiotics and MPs before and after aging showed different effects on ENPs.Aged polyamide prevented aggregation of ZnONPs by introducing negative charges,whereas virgin polyamide affected ZnONPs with the help of electrostatic attraction.FT-IR and XPS analyses were used to probe the physicochemical interactions between ENPs and MPs.The results showed no chemical interaction and electrostatic interactionwas the dominant force between them.Furthermore,the adsorption rate of antibiotics positively correlated with pH and humic acid but exhibited a negative correlation with ionic strength.Our study highlights that ENPs are highly capable of accumulating and transporting antibiotics in the presence of MPs,which could result in a widespread distribution of antibiotics and an expansion of their environmental risks and toxic effects on biota.It also improves our understanding of the mutual interaction of various co-existing contaminants in aqueous environments.展开更多
Hydrothermal carbonization(HTC)is a thermochemical conversion technology to produce hydrochar from wet biomass without drying,but it is time-consuming and expensive to experimentally determine the optimal HTC operatio...Hydrothermal carbonization(HTC)is a thermochemical conversion technology to produce hydrochar from wet biomass without drying,but it is time-consuming and expensive to experimentally determine the optimal HTC operational conditions of specific biomass to produce desired hydrochar.Therefore,a machine learning(ML)approach was used to predict and optimize hydrochar properties.Specifically,biochemical components(proteins,lipids,and carbohydrates)of biomass were predicted and analyzed first via elementary composition.Then,accurate single-biomass(no mixture)based ML multi-target models(average R^(2)=0.93 and RMSE=2.36)were built to predict and optimize the hydrochar properties(yield,elemental composition,elemental atomic ratio,and higher heating value).Biomass composition(elemental and biochemical),proximate analyses,and HTC conditions were inputs herein.Interpretation of the model results showed that ash,temperature,and the N and C content of biomass were the most critical factors affecting the hydrochar properties,and that the relative importance of biochemical composition(25%)for the hydrochar was higher than that of operating conditions(19%).Finally,an intelligent system was constructed based on a multi-target model,verified by applying it to predict the atomic ratios(N/C,O/C,and H/C).It could also be extended to optimize hydrochar production from the HTC of single-biomass samples with experimental validation and to predict hydrochar from the co-HTC of mixed biomass samples reported in the literature.This study advances the field by integrating predictive modeling,intelligent systems,and mechanistic insights,offering a holistic approach to the precise control and optimization of hydrochar production through HTC.展开更多
基金financially supported by the Science and Technology Innovation Program of Hunan Province(2024AQ2008)。
文摘The fly ash from waste incineration poses a serious threat to human health due to its high content of dioxins.Hydrothermal treatment is an efficient and clean method on the decomposition and detoxifying of fly ash.To study the degradation mechanism of dioxins,this paper uses molecular dynamics(MD)to simulate the hydrothermal reaction process of polychlorinated dibenzo-p-dioxins(PCDDs)under different conditions,and the degradation mechanism of PCDDs is obtained.The results show that the degradation of PCDDs includes two pathways:the first pathway is the substitution of Cl groups by hydroxyl groups to form low-chlorine substitution products through direct hydrogenation,and the second pathway is the formation of non-toxic benzene ring structures accompanied by the cleavage of C—O bonds.The two degradation pathways of PCDDs well explain the changes in toxicity before and after the hydrothermal treatment of fly ash,which is consistent with experimental results.This study provides theoretical guidance for the harmless treatment process of fly ash via hydrothermal method.
基金supported by the National Youth Foundation of China(No.52000064)the National Natural Science Foundation of China(No.U20A20323)+5 种基金the Natural Science Foundation of Hunan Province(No.2023JJ0013)the Special Funding for the Construction of Hunan’s Innovative Province(No.2021SK2040)the Science and Technology Innovation Program of Hunan Province(No.2021RC3133)the National Youth Foundation of China(No.52300227)the HunanMunicipal Natural Science Foundation(No.2023JJ41048)the Changsha Municipal Natural Science Foundation(No.kq2208423).
文摘Microplastics(MPs)are of particular concern due to their ubiquitous occurrence and propensity to interact and concentrate various waterborne contaminants from aqueous surroundings.Studies on the interaction and joint toxicity of MPs on engineered nanoparticles(ENPs)are exhaustive,but limited research on the effect of MPs on the properties of ENPs in multisolute systems.Here,the effect of MPs on adsorption ability of ENPs to antibiotics was investigated for the first time.The results demonstrated that MPs enhanced the adsorption affinity of ENPs to antibiotics and MPs before and after aging showed different effects on ENPs.Aged polyamide prevented aggregation of ZnONPs by introducing negative charges,whereas virgin polyamide affected ZnONPs with the help of electrostatic attraction.FT-IR and XPS analyses were used to probe the physicochemical interactions between ENPs and MPs.The results showed no chemical interaction and electrostatic interactionwas the dominant force between them.Furthermore,the adsorption rate of antibiotics positively correlated with pH and humic acid but exhibited a negative correlation with ionic strength.Our study highlights that ENPs are highly capable of accumulating and transporting antibiotics in the presence of MPs,which could result in a widespread distribution of antibiotics and an expansion of their environmental risks and toxic effects on biota.It also improves our understanding of the mutual interaction of various co-existing contaminants in aqueous environments.
基金supported by the National Key Research and Development Program of China(2021YFE0104900)the Open Project of Xiangjiang Laboratory(22xj03003)the Science and Technology Innovation Program of Hunan Province(2021RC4005,2021GK1210).
文摘Hydrothermal carbonization(HTC)is a thermochemical conversion technology to produce hydrochar from wet biomass without drying,but it is time-consuming and expensive to experimentally determine the optimal HTC operational conditions of specific biomass to produce desired hydrochar.Therefore,a machine learning(ML)approach was used to predict and optimize hydrochar properties.Specifically,biochemical components(proteins,lipids,and carbohydrates)of biomass were predicted and analyzed first via elementary composition.Then,accurate single-biomass(no mixture)based ML multi-target models(average R^(2)=0.93 and RMSE=2.36)were built to predict and optimize the hydrochar properties(yield,elemental composition,elemental atomic ratio,and higher heating value).Biomass composition(elemental and biochemical),proximate analyses,and HTC conditions were inputs herein.Interpretation of the model results showed that ash,temperature,and the N and C content of biomass were the most critical factors affecting the hydrochar properties,and that the relative importance of biochemical composition(25%)for the hydrochar was higher than that of operating conditions(19%).Finally,an intelligent system was constructed based on a multi-target model,verified by applying it to predict the atomic ratios(N/C,O/C,and H/C).It could also be extended to optimize hydrochar production from the HTC of single-biomass samples with experimental validation and to predict hydrochar from the co-HTC of mixed biomass samples reported in the literature.This study advances the field by integrating predictive modeling,intelligent systems,and mechanistic insights,offering a holistic approach to the precise control and optimization of hydrochar production through HTC.
