The impact of field aged biochar(FABC)on the adsorption kinetics and transport behavior of weakly hydrophobic antibiotics in soil is scarcely discussed.This study investigated the impact of FABC on weakly hydrophobic ...The impact of field aged biochar(FABC)on the adsorption kinetics and transport behavior of weakly hydrophobic antibiotics in soil is scarcely discussed.This study investigated the impact of FABC on weakly hydrophobic antibiotics(sulfadiazine,SD and florfenicol,FF)transport in purple soil by comparing fresh biochar(FBC),one-year aged biochar(ABC1),and five-year aged biochar(ABC5).Through batch adsorption,soil column experiments,and Hydrus 1D modeling,this study examined the evolution of physicochemical properties of biochar,their effects on soil porosity and dispersion,and antibiotic adsorption.Results showed that aging significantly altered biochar characteristics,with carbon(C)content decreasing by 10.40%while oxygen(O)content increased by 40.52%.ABC1 demonstrated optimal performance with a 99.28%increase in specific surface area(SSA)and enhanced oxygen-containing functional groups,leading to maximum antibiotic retention rates of 16.57%for SD and 24.78%for FF.Although ABC5 showed decreased SSA and adsorption capacity,it maintained stable remediation effects through enhanced biochar–soil interactions,as evidenced by increased dispersivity(λ)and hydrodynamic dispersion coefficient(D).The two-site chemical nonequilibrium model(TSM)revealed that the fraction of equilibrium adsorption sites(f)increased from 0.1164 to 0.3514 after aging,indicating improved antibiotic retention.These findings demonstrate that while one-year aging enhanced remediation capacity,five-year aging stabilized environmental effects through modified soil structure.展开更多
A new Ag/AgCl sensor for measuring marine electric fields was prepared and characterized through electrochemical methods and scanning electron microscopy.Its performance was evaluated in both laboratory and deep-water...A new Ag/AgCl sensor for measuring marine electric fields was prepared and characterized through electrochemical methods and scanning electron microscopy.Its performance was evaluated in both laboratory and deep-water settings.The study indicates that the double-pulse electrodeposition method is advantageous for producing Ag/AgCl sensors that maintain excellent stability over time.During a 20-day continuous stability test,the potential difference of the sensor consistently remained between -24.76μV and 62.07μV,with a minimum potential difference drift of 2.77μV per 24 h.All sensors accurately detected artificial signals in both the time and frequency domains,and their responses were consistent with one another.The minimum noise level of the sensor was 0.59 nV(√Hz)^(-1)@1 Hz.The sensor performed well in high-precision electric field measurements at a depth of approximately 2800 m in the South China Sea.The high stability and low noise level of the sensor make it an effective tool for detecting electrical conductivity structures beneath the seafloor.展开更多
Aging of binder affects the service life of flexible pavements.Binder’s aging involves changes in its physical,rheological,chemical,and morphological characteristics,making it hard and brittle and resulting in paveme...Aging of binder affects the service life of flexible pavements.Binder’s aging involves changes in its physical,rheological,chemical,and morphological characteristics,making it hard and brittle and resulting in pavement deterioration.Oxidation and volatalization are two main mechanisms involved in aging.Aging stiffens the binder as it increases the viscosity of binder resulting in pavement distresses like fatigue cracking,ravelling,and thermal cracking.Hence,it is obligatory to examine the aging effects on binder to predict the service life of flexible pavements.In this study,core samples are collected from 15 years aged in-service pavement section,and fresh binder was aged for varying aging duration in the laboratory to simulate field aging condition.Field aged and laboratory aged binders were subjected to physical,chemical,rheological,and morphological investigations for evaluating the variation of these properties with long-term aging(LTA).It is evident that the traffic speed influences the dynamic viscosity of binders.With aging,the rutting resis-tance of binders improved,and fatigue resistance of binders diminished considerably.15 years field aging condition is simulated in the laboratory,and the results showed that the severity of aging in binder increases with the pavement depth in the field.展开更多
基金supported by Natural Science Foundation of Sichuan Province,China(2024NSFSC0837)the Fundamental Research Funds for the Central Public-interest Scientific Institution(2024YYSKY-05)+1 种基金the Open Research Fund of Key Laboratory of Eco-industry of Ministry of Ecology and Environment,Chinese Research Academy of Environmental Sciences(2024KFF-04)the Key Research and Development Program of Ganzi Prefecture’s Science and Technology Plan(24kjjh0005).
文摘The impact of field aged biochar(FABC)on the adsorption kinetics and transport behavior of weakly hydrophobic antibiotics in soil is scarcely discussed.This study investigated the impact of FABC on weakly hydrophobic antibiotics(sulfadiazine,SD and florfenicol,FF)transport in purple soil by comparing fresh biochar(FBC),one-year aged biochar(ABC1),and five-year aged biochar(ABC5).Through batch adsorption,soil column experiments,and Hydrus 1D modeling,this study examined the evolution of physicochemical properties of biochar,their effects on soil porosity and dispersion,and antibiotic adsorption.Results showed that aging significantly altered biochar characteristics,with carbon(C)content decreasing by 10.40%while oxygen(O)content increased by 40.52%.ABC1 demonstrated optimal performance with a 99.28%increase in specific surface area(SSA)and enhanced oxygen-containing functional groups,leading to maximum antibiotic retention rates of 16.57%for SD and 24.78%for FF.Although ABC5 showed decreased SSA and adsorption capacity,it maintained stable remediation effects through enhanced biochar–soil interactions,as evidenced by increased dispersivity(λ)and hydrodynamic dispersion coefficient(D).The two-site chemical nonequilibrium model(TSM)revealed that the fraction of equilibrium adsorption sites(f)increased from 0.1164 to 0.3514 after aging,indicating improved antibiotic retention.These findings demonstrate that while one-year aging enhanced remediation capacity,five-year aging stabilized environmental effects through modified soil structure.
基金supported by the National Natural Science Foundation of China(Nos.U23B20158,91958210,42004055)。
文摘A new Ag/AgCl sensor for measuring marine electric fields was prepared and characterized through electrochemical methods and scanning electron microscopy.Its performance was evaluated in both laboratory and deep-water settings.The study indicates that the double-pulse electrodeposition method is advantageous for producing Ag/AgCl sensors that maintain excellent stability over time.During a 20-day continuous stability test,the potential difference of the sensor consistently remained between -24.76μV and 62.07μV,with a minimum potential difference drift of 2.77μV per 24 h.All sensors accurately detected artificial signals in both the time and frequency domains,and their responses were consistent with one another.The minimum noise level of the sensor was 0.59 nV(√Hz)^(-1)@1 Hz.The sensor performed well in high-precision electric field measurements at a depth of approximately 2800 m in the South China Sea.The high stability and low noise level of the sensor make it an effective tool for detecting electrical conductivity structures beneath the seafloor.
文摘Aging of binder affects the service life of flexible pavements.Binder’s aging involves changes in its physical,rheological,chemical,and morphological characteristics,making it hard and brittle and resulting in pavement deterioration.Oxidation and volatalization are two main mechanisms involved in aging.Aging stiffens the binder as it increases the viscosity of binder resulting in pavement distresses like fatigue cracking,ravelling,and thermal cracking.Hence,it is obligatory to examine the aging effects on binder to predict the service life of flexible pavements.In this study,core samples are collected from 15 years aged in-service pavement section,and fresh binder was aged for varying aging duration in the laboratory to simulate field aging condition.Field aged and laboratory aged binders were subjected to physical,chemical,rheological,and morphological investigations for evaluating the variation of these properties with long-term aging(LTA).It is evident that the traffic speed influences the dynamic viscosity of binders.With aging,the rutting resis-tance of binders improved,and fatigue resistance of binders diminished considerably.15 years field aging condition is simulated in the laboratory,and the results showed that the severity of aging in binder increases with the pavement depth in the field.
