Adsorption Of Environmental Antibiotics On Straw Biomass Carbon Materials Prepared By Different Methods

In recent years,antibiotics pollution are becoming the subject of growing concern.Due to the special surface structure and strong adsorption properties,biomass carbonaceous material as a new type of environmental functional material has received increasing attention in soil amendment.In this paper,we devoted to use waste maize straw of pastoral areas of Inner Mongolia as feedstock to produce carbonaceous material.The different preparation methods were adopted including burning in an open natural condition(BC_natural),pyrolysis at 700?(BC₇₀₀)and hydrothermal method?HTC?.Biochars?BC?obtained by pyrolysis were incubated in different kinds of soils,in order to examine the effect of aging treatment on the properties of BC.Three different typical antibiotics,Oxytetracycline?OTC?,Sulfamerazine?SMR?and Streptomycin?STR?,were selected as target pollutants to study the adsorption characteristics of biomass carbon materials prepared by different methods.1.In contrast,BC₇₀₀ had stronger aromaticity and stability,larger specific surface area,and BC_naturalatural had more surface functional groups and higher mineral content.BC₇₀₀ had stronger adsorption for OTC,SMR and STR than BC_natural,moreover,adsorption capacity of three antibiotics on BC follows:OTC>STR>SMR.2.Solution pH,ionic strength,and combined heavy metal contaminants can affect absorption of antibiotics to maize-straw-derived biochar.Pore-filling and?-?EDA interaction played a role in the adsorption of antibiotics.In addition,the STR,which exist mainly as cations,involveed electrostatic interactions and surface functional groups interactions during the adsorption process.While the main adsorption mechanism of OTC was surface functional group interactions.Adsorption of SMR on BC was mainly controlled by hydrophobic interactions.3.Aromaticity and total pore volumes markedly increased for both aged BC,because dissolved carbon can be readily released from bulk BC after the aging process.Biochars aged for 90 days in soil still had stronger sorption capacity for three antibiotics.The adsorption of OTC increased obviously on biochars after aging in Hohhot soil.The adsorption of SMR increased markedly on biochars after aging in Jiangxi soil.The adsorption of STR on BC_natural after aging in both soils increased,while the aged BC₇₀₀ had no significant change in its adsorption capacity.4.Hydrochars?HTC?with microsphere structure was prepared by hydrothermal carbonization method.The reaction time and acid/base additives affected the structure and adsorption properties of HTC.The adsorption capacity of antibiotics to HTC was between BC_natural and BC₇₀₀.HTC-K12 prepared by addition of KOH for 12h had higher surface acidity functional groups,larger pore size,and maximum adsorption capacity for OTC and STR.The HTC-P12 prepared by adding H₃PO₄ had a larger specific surface area and hydrophobicity,and maximum adsorption performance for SMR.