The sequestration of^(99)Tc represents one of the most challenging tasks in nuclear waste decontamination In the event of a radioactive waste leak,^(99)TcO_(4)^(-)(a main form of^(99)Tc)would spread into the groundwa ...The sequestration of^(99)Tc represents one of the most challenging tasks in nuclear waste decontamination In the event of a radioactive waste leak,^(99)TcO_(4)^(-)(a main form of^(99)Tc)would spread into the groundwa ter,a scenario difficult to address with conventional anion exchange materials like resin and inorganic cationic sorbents.Herein,we present a nickel(II)metal-organic framework(MOF),TNU-143,featuring3D four-fold interpenetrated networks.TNU-143 exhibits efficient ReO_(4)^(-)(a nonradioactive analogue o^(99)TcO_(4)^(–))removal with fast anion exchange kinetics(<1 min),high sorption capacity(844 mg/g for ReO_(4)^(-))and outstanding selectivity over common anions.More importantly,TNU-143 shows superior stability in alkaline solution and can remove 91.6%ReO_(4)^(-)from simulated alkaline high-level waste(HLW)stream with solid-liquid ratio of 40 g/L.The uptake mechanism is elucidated by the single-crystal structure o TNU-143(Re),showing that ReO_(4)^(-)anions are firmly coordinated to nickel cation to result in a 2D lay ered structures.Density functional theory(DFT)calculations confirm the transformation from TNU-143 to TNU-143(Re)is a thermodynamically favorable process.This work presents a new approach to the removal of Re O_(4)^(-)/^(99)TcO_(4)^(-)from alkaline nulcear fuel using MOF sorbents.展开更多
Groundwater arsenic (As) contamination is a hot issue,which is severe health concern worldwide.Recently,many Fe-based adsorbents have been used for As removal from solutions.Modified granular natural siderite (MGNS),a...Groundwater arsenic (As) contamination is a hot issue,which is severe health concern worldwide.Recently,many Fe-based adsorbents have been used for As removal from solutions.Modified granular natural siderite (MGNS),a special hybrid Fe(II)/Fe(III) system,had higher adsorption capacity for As(III) than As(V),but the feasibility of its application in treating high-As groundwater is still unclear.In combination with transport modeling,laboratory column studies and field pilot tests were performed to reveal both mechanisms and factors controlling As removal by MGNS-filled filters.Results show that weakly acid pH and discontinuous treatment enhanced As(III) removal,with a throughput of 8700 bed volumes (BV) of 1.0 mg/L As(III) water at breakthrough of 10 mg/L As at pH 6.Influent HCO3^- inhibited As removal by the filters.Iron mineral species,SEM and XRD patterns of As-loading MGNS show that the important process contributing to high As(III) removal was the mineral transformation from siderite to goethite in the filter.The homogeneous surface diffusion modeling (HSDM) shows that competition between As(III) and HCO3^- with adsorption sites on MGNS was negligible.The inhibition of HCO3^- on As(III) removal was connected to inhibition of siderite dissolution and mineral transformation.Arsenic loadings were lower in field pilot tests than those in the laboratory experiments,showing that high concentrations of coexisting anions (especially HCO3^-- and SiO4^4-),high pH,low EBCT,and low groundwater temperature decreased As removal.It was suggested that acidification and aeration of high- As groundwater and discontinuous treatment would improve the MGNS filter performance of As removal from real high-As groundwater.展开更多
Microplastics(MPs)are recognized as vectors for the transport of organic contaminants in aquatic environments in addition to their own adverse effects on aquatic organisms.Per-and polyfluoroalkyl substances(PFASs)are ...Microplastics(MPs)are recognized as vectors for the transport of organic contaminants in aquatic environments in addition to their own adverse effects on aquatic organisms.Per-and polyfluoroalkyl substances(PFASs)are widely present in aquatic environments due to their widespread applications,and thus coexist with MPs.Therefore,we focus on the interaction of MPs and PFASs and related combined toxicity in aquatic environments in this work The adsorption of PFASs on MPs is critically reviewed,and new mechanisms such as halogen bonding,π-πinteraction,cation-πinteractions,and micelle formation are proposed.Moreover,the effect of MPs on the transport and transformation of PFASs in aquatic environments is discussed.Based on four typical aquatic organisms(shellfish,Daphnia,algae,and fish),the toxicity of MPs and/or PFASs at the organismal or molecular levels is also evaluated and summarized.Finally,challenges and research perspectives are proposed,and the roles of the shapes and aging process of MPs on PFAS biogeochemical processes and toxicity,especially on PFAS substitutes,are recommended for further investigation.This review provides a better understanding of the interactions and toxic effects of coexisting MPs and PFASs in aquatic environments.展开更多
DNA is the genetic material of various organisms. Extracellular DNA adsorbed or bound on surface-active particles in soils has been shown to persist for long periods against nucleases degradation and still retain the ...DNA is the genetic material of various organisms. Extracellular DNA adsorbed or bound on surface-active particles in soils has been shown to persist for long periods against nucleases degradation and still retain the ability to transform competent cells. This paper reviews some recent advances on the binding and transformation of extracellular DNA in soils, which is fundamental to understanding the nature of the soil, regulating biodiversity, and assessing the risk of releasing genetically engineered microo…展开更多
基金supported by National Natural Science Foundation of China(No.22171210)Research Project of Tianjin Education Commission(No.2023KJ182)Tianjin Research Innovation Project for Postgraduate Students(No.2022BKY200)。
文摘The sequestration of^(99)Tc represents one of the most challenging tasks in nuclear waste decontamination In the event of a radioactive waste leak,^(99)TcO_(4)^(-)(a main form of^(99)Tc)would spread into the groundwa ter,a scenario difficult to address with conventional anion exchange materials like resin and inorganic cationic sorbents.Herein,we present a nickel(II)metal-organic framework(MOF),TNU-143,featuring3D four-fold interpenetrated networks.TNU-143 exhibits efficient ReO_(4)^(-)(a nonradioactive analogue o^(99)TcO_(4)^(–))removal with fast anion exchange kinetics(<1 min),high sorption capacity(844 mg/g for ReO_(4)^(-))and outstanding selectivity over common anions.More importantly,TNU-143 shows superior stability in alkaline solution and can remove 91.6%ReO_(4)^(-)from simulated alkaline high-level waste(HLW)stream with solid-liquid ratio of 40 g/L.The uptake mechanism is elucidated by the single-crystal structure o TNU-143(Re),showing that ReO_(4)^(-)anions are firmly coordinated to nickel cation to result in a 2D lay ered structures.Density functional theory(DFT)calculations confirm the transformation from TNU-143 to TNU-143(Re)is a thermodynamically favorable process.This work presents a new approach to the removal of Re O_(4)^(-)/^(99)TcO_(4)^(-)from alkaline nulcear fuel using MOF sorbents.
基金financially supported by National Natural Science Foundation of China (Grant Nos.41672225 and 41222020)the Fundamental Research Funds for the Central Universities (Grant No.2652013028)the Fok Ying Tung Education Foundation, China (Grant No.131017)
文摘Groundwater arsenic (As) contamination is a hot issue,which is severe health concern worldwide.Recently,many Fe-based adsorbents have been used for As removal from solutions.Modified granular natural siderite (MGNS),a special hybrid Fe(II)/Fe(III) system,had higher adsorption capacity for As(III) than As(V),but the feasibility of its application in treating high-As groundwater is still unclear.In combination with transport modeling,laboratory column studies and field pilot tests were performed to reveal both mechanisms and factors controlling As removal by MGNS-filled filters.Results show that weakly acid pH and discontinuous treatment enhanced As(III) removal,with a throughput of 8700 bed volumes (BV) of 1.0 mg/L As(III) water at breakthrough of 10 mg/L As at pH 6.Influent HCO3^- inhibited As removal by the filters.Iron mineral species,SEM and XRD patterns of As-loading MGNS show that the important process contributing to high As(III) removal was the mineral transformation from siderite to goethite in the filter.The homogeneous surface diffusion modeling (HSDM) shows that competition between As(III) and HCO3^- with adsorption sites on MGNS was negligible.The inhibition of HCO3^- on As(III) removal was connected to inhibition of siderite dissolution and mineral transformation.Arsenic loadings were lower in field pilot tests than those in the laboratory experiments,showing that high concentrations of coexisting anions (especially HCO3^-- and SiO4^4-),high pH,low EBCT,and low groundwater temperature decreased As removal.It was suggested that acidification and aeration of high- As groundwater and discontinuous treatment would improve the MGNS filter performance of As removal from real high-As groundwater.
基金funded by the National Natural Science Foundation of China(Nos.U2106213,41907332,and 42192572)the National Postdoctoral Program for Innovative Talents of China(BX20190306)+2 种基金the Taishan Scholars Program of Shandong Province(China)(tsqn201909051)the Fundamental Research Funds for the Central Universities(China)(202141003)the USDA Hatch Program(USA)(MAS 00549).
文摘Microplastics(MPs)are recognized as vectors for the transport of organic contaminants in aquatic environments in addition to their own adverse effects on aquatic organisms.Per-and polyfluoroalkyl substances(PFASs)are widely present in aquatic environments due to their widespread applications,and thus coexist with MPs.Therefore,we focus on the interaction of MPs and PFASs and related combined toxicity in aquatic environments in this work The adsorption of PFASs on MPs is critically reviewed,and new mechanisms such as halogen bonding,π-πinteraction,cation-πinteractions,and micelle formation are proposed.Moreover,the effect of MPs on the transport and transformation of PFASs in aquatic environments is discussed.Based on four typical aquatic organisms(shellfish,Daphnia,algae,and fish),the toxicity of MPs and/or PFASs at the organismal or molecular levels is also evaluated and summarized.Finally,challenges and research perspectives are proposed,and the roles of the shapes and aging process of MPs on PFAS biogeochemical processes and toxicity,especially on PFAS substitutes,are recommended for further investigation.This review provides a better understanding of the interactions and toxic effects of coexisting MPs and PFASs in aquatic environments.
文摘DNA is the genetic material of various organisms. Extracellular DNA adsorbed or bound on surface-active particles in soils has been shown to persist for long periods against nucleases degradation and still retain the ability to transform competent cells. This paper reviews some recent advances on the binding and transformation of extracellular DNA in soils, which is fundamental to understanding the nature of the soil, regulating biodiversity, and assessing the risk of releasing genetically engineered microo…
