The use of biochars formed by hydrothermal carbonization for the treatment of contaminated water has been greatly limited, due to their poorly developed porosity and low content of surface functional groups. Also, the...The use of biochars formed by hydrothermal carbonization for the treatment of contaminated water has been greatly limited, due to their poorly developed porosity and low content of surface functional groups. Also, the most common modification routes inevitably require post-treatment processes, which are time-consuming and energy-wasting. Hence, the objective of this research was to produce a cost-effective biochar with improved performance for the treatment of heavy metal pollution through a facile one-step hydrothermal carbonization process coupled with ammonium phosphate, thiocarbamide, ammonium chloride or urea, without any posttreatment. The effects of various operational parameters, including type of modification reagent, time and temperature of hydrothermal treatment, and ratio of modification reagent to precursor during impregnation, on the copper ion adsorption were examined. The adsorption data fit the Langmuir adsorption isotherm model quite well. The maximum adsorption capacities （mg/g） of the biochars towards copper ions followed the order of 40-8h-1.0-APBC （95.24） 〉 140-Sh-O-BC （12.52） 〉 140-8h-1.0-TUBC （12.08） 〉 140-Sh-1.0-ACBC （7.440） 〉 140-Sh-1.0-URBC （5.277）. The results indicated that biochars modified with ammonium phosphate displayed excellent adsorption performance toward copper ions, which was 7.6-fold higher than that of the pristine biochar. EDX and FT-IR analyses before and after adsorption demonstrated that the main removal mechanism involved complexation between the phosphate groups on the surface of the modified biochars and copper ions.展开更多
Biochar is considered a potential technology to enhance chemical fertilizer use efficiency through intensification of the interactions between nutrients and the functional groups on biochar surfaces.However,little is ...Biochar is considered a potential technology to enhance chemical fertilizer use efficiency through intensification of the interactions between nutrients and the functional groups on biochar surfaces.However,little is known about how the application of activated biochars mixed with urea influences nitrogen(N)mineralization and crop performance in paddy fields.Here,a sawdust-derived fresh biochar(FBC)(ca.400℃)was activated chemically with 15%hydrogen peroxide and biologically with a nutrient solution mixed with a soil inoculum to obtain a chemically activated biochar(CBC)and a biologically activated biochar(BBC),respectively.The chemical and surface properties of FBC,CBC,and BBC were evaluated using spectroscopic methods,i.e.,Fourier transform infrared spectroscopy and 13C nuclear magnetic resonance,and potentiometric charge determination.The N retention capacity of biochars and their interaction with urea hydrolysis were examined in a laboratory incubation experiment.Additionally,a field experiment was carried out in a paddy field with the biochars unmixed or mixed with urea at a 1:1 ratio.Our results showed that negative surface functional groups and negative charges were increased on both activated biochars,especially CBC.Both activated biochars contributed to a significant reduction in urea-biochar suspension pH and increased N retention in the incubation experiment.Despite the enhanced surface properties of the activated biochars,no similar increases in rice biomass and grain yield were observed for these biochars in the field experiment.However,rice biomass,grain yield,apparent N use efficiency,and agronomic N use efficiency were significantly higher with the application of the three biochars compared to no-biochar application.Altogether,the results indicate that the application of urea mixed with biochar could enhance crop performance,especially in the case of activated biochar,which would enhance N retention in the soil,reducing N loss.展开更多
Biochar is a carbon-rich material produced through the pyrolysis of various feedstocks.It can be further modified to enhance its properties and is referred to as modified biochar(MB).The research interest in MB applic...Biochar is a carbon-rich material produced through the pyrolysis of various feedstocks.It can be further modified to enhance its properties and is referred to as modified biochar(MB).The research interest in MB application in soil has been on the surge over the past decade.However,the potential benefits of MB are considerable,and its efficiency can be subject to various influencing factors.For instance,unknown physicochemical characteristics,outdated analytical techniques,and a limited understanding of soil factors that could impact its effectiveness after application.This paper reviewed the recent literature pertaining to MB and its evolved physicochemical characteristics to provide a comprehensive understanding beyond synthesis techniques.These include surface area,porosity,alkalinity,pH,elemental composition,and functional groups.Furthermore,it explored innovative analytical methods for characterizing these properties and evaluating their effectiveness in soil applications.In addition to exploring the potential benefits and limitations of utilizing MB as a soil amendment,this article delved into the soil factors that influence its efficacy,along with the latest research findings and advancements in MB technology.Overall,this study will facilitate the synthesis of current knowledge and the identification of gaps in our understanding of MB.展开更多
Emerging contaminants(ECs)pose a growing threat to the agricultural ecosystems and human health.Biochar(BC)may be applied for the remediation of ECs in soils and water.There are some research papers that have been pub...Emerging contaminants(ECs)pose a growing threat to the agricultural ecosystems and human health.Biochar(BC)may be applied for the remediation of ECs in soils and water.There are some research papers that have been published about the potentiality of BC for the remediation of ECs in soils and water;however,there have been no critical and comprehensive review articles published on this topic up to now.Therefore,this review explores the application of pristine and modified BC for the remediation of various emerging inorganic contaminants(EICs),including vanadium(V),antimony(Sb),thallium(Tl),mercury(Hg),fluoride(F−),and rare earth elements(REEs)in soils and water.The review explores the specific mechanisms by which BC removes these EICs from water and soil.The roles of ion exchange,complexation,electrostatic interactions,and precipitation in the removal of these EICs from water by pristine and functionalized BC have been reviewed and discussed.Particular attention is also paid to the interaction and potential immobilization of those EICs in soils with pristine and functionalized BC,highlighting some applicable strategies for treating EIC-contaminated soils,particularly paddy soils,aiming to mitigate the associated ecological and human health risks.Finally,the potential environmental implications and further research on the applications of pristine and functionalized BC for remediation of EICs in water and soils have been summarized.This article provides a comprehensive overview on the potential applications of different pristine and engineered BCs for the sustainable remediation of EICs contaminated soils and water.展开更多
基金supported by the Tai Shan Scholar Foundation(No.ts201511003)the Fundamental Research Funds for the Central Universities(No.DUT17RC(3)044)
文摘The use of biochars formed by hydrothermal carbonization for the treatment of contaminated water has been greatly limited, due to their poorly developed porosity and low content of surface functional groups. Also, the most common modification routes inevitably require post-treatment processes, which are time-consuming and energy-wasting. Hence, the objective of this research was to produce a cost-effective biochar with improved performance for the treatment of heavy metal pollution through a facile one-step hydrothermal carbonization process coupled with ammonium phosphate, thiocarbamide, ammonium chloride or urea, without any posttreatment. The effects of various operational parameters, including type of modification reagent, time and temperature of hydrothermal treatment, and ratio of modification reagent to precursor during impregnation, on the copper ion adsorption were examined. The adsorption data fit the Langmuir adsorption isotherm model quite well. The maximum adsorption capacities （mg/g） of the biochars towards copper ions followed the order of 40-8h-1.0-APBC （95.24） 〉 140-Sh-O-BC （12.52） 〉 140-8h-1.0-TUBC （12.08） 〉 140-Sh-1.0-ACBC （7.440） 〉 140-Sh-1.0-URBC （5.277）. The results indicated that biochars modified with ammonium phosphate displayed excellent adsorption performance toward copper ions, which was 7.6-fold higher than that of the pristine biochar. EDX and FT-IR analyses before and after adsorption demonstrated that the main removal mechanism involved complexation between the phosphate groups on the surface of the modified biochars and copper ions.
基金grateful to the Ministry of Education,Bangladesh for funding the current work with a project(No.LS2018770)the financial support for chemical analysis provided by Spanish Ministry of Science,Innovation and Universities,Spain and the European Regional Development Fund from the European Union(EU FEDER)(No.RTI2018-099417-B-I00)thankful for receiving a fund from the Kubota Consultancy,The Netherlands(No.3710473400-2).
文摘Biochar is considered a potential technology to enhance chemical fertilizer use efficiency through intensification of the interactions between nutrients and the functional groups on biochar surfaces.However,little is known about how the application of activated biochars mixed with urea influences nitrogen(N)mineralization and crop performance in paddy fields.Here,a sawdust-derived fresh biochar(FBC)(ca.400℃)was activated chemically with 15%hydrogen peroxide and biologically with a nutrient solution mixed with a soil inoculum to obtain a chemically activated biochar(CBC)and a biologically activated biochar(BBC),respectively.The chemical and surface properties of FBC,CBC,and BBC were evaluated using spectroscopic methods,i.e.,Fourier transform infrared spectroscopy and 13C nuclear magnetic resonance,and potentiometric charge determination.The N retention capacity of biochars and their interaction with urea hydrolysis were examined in a laboratory incubation experiment.Additionally,a field experiment was carried out in a paddy field with the biochars unmixed or mixed with urea at a 1:1 ratio.Our results showed that negative surface functional groups and negative charges were increased on both activated biochars,especially CBC.Both activated biochars contributed to a significant reduction in urea-biochar suspension pH and increased N retention in the incubation experiment.Despite the enhanced surface properties of the activated biochars,no similar increases in rice biomass and grain yield were observed for these biochars in the field experiment.However,rice biomass,grain yield,apparent N use efficiency,and agronomic N use efficiency were significantly higher with the application of the three biochars compared to no-biochar application.Altogether,the results indicate that the application of urea mixed with biochar could enhance crop performance,especially in the case of activated biochar,which would enhance N retention in the soil,reducing N loss.
文摘Biochar is a carbon-rich material produced through the pyrolysis of various feedstocks.It can be further modified to enhance its properties and is referred to as modified biochar(MB).The research interest in MB application in soil has been on the surge over the past decade.However,the potential benefits of MB are considerable,and its efficiency can be subject to various influencing factors.For instance,unknown physicochemical characteristics,outdated analytical techniques,and a limited understanding of soil factors that could impact its effectiveness after application.This paper reviewed the recent literature pertaining to MB and its evolved physicochemical characteristics to provide a comprehensive understanding beyond synthesis techniques.These include surface area,porosity,alkalinity,pH,elemental composition,and functional groups.Furthermore,it explored innovative analytical methods for characterizing these properties and evaluating their effectiveness in soil applications.In addition to exploring the potential benefits and limitations of utilizing MB as a soil amendment,this article delved into the soil factors that influence its efficacy,along with the latest research findings and advancements in MB technology.Overall,this study will facilitate the synthesis of current knowledge and the identification of gaps in our understanding of MB.
文摘Emerging contaminants(ECs)pose a growing threat to the agricultural ecosystems and human health.Biochar(BC)may be applied for the remediation of ECs in soils and water.There are some research papers that have been published about the potentiality of BC for the remediation of ECs in soils and water;however,there have been no critical and comprehensive review articles published on this topic up to now.Therefore,this review explores the application of pristine and modified BC for the remediation of various emerging inorganic contaminants(EICs),including vanadium(V),antimony(Sb),thallium(Tl),mercury(Hg),fluoride(F−),and rare earth elements(REEs)in soils and water.The review explores the specific mechanisms by which BC removes these EICs from water and soil.The roles of ion exchange,complexation,electrostatic interactions,and precipitation in the removal of these EICs from water by pristine and functionalized BC have been reviewed and discussed.Particular attention is also paid to the interaction and potential immobilization of those EICs in soils with pristine and functionalized BC,highlighting some applicable strategies for treating EIC-contaminated soils,particularly paddy soils,aiming to mitigate the associated ecological and human health risks.Finally,the potential environmental implications and further research on the applications of pristine and functionalized BC for remediation of EICs in water and soils have been summarized.This article provides a comprehensive overview on the potential applications of different pristine and engineered BCs for the sustainable remediation of EICs contaminated soils and water.
