The Sorption Mechanisims Of Ciprofloxacin Onto Biochars

The contamination of farmland soil by anbiotics has aroused widely concerned due to its serious risk to human health,immobilize and remediate the antibiotic contaminated soil has attracted extensive studies.Biochars,as a new environmental material,has been widely used as an prosing soil amendment,owing to the strong adsorption affinity for organic pollutants or heavy metals.However,the coexisting of heavy metals and dissolved organic matter(DOM)in soil environment can interact with biochars and consequently to affect their adsorption.In this dissertation,research advance on the sorption of organic pollutants onto biochars was reviewed.After that,the interactions between Ciprofloxacin(CIP)and Cu2+onto biochars,as well as the effects of dissolved organic matter derived from chicken manure(CMDOM)on the adsorption of CIP and Cu2+ onto biochars were investigated;A new method was applied in this study to synthesize g-MoS2-BC composites by coating g-MoS2 nanosheets into original biochar and its adsorption behavior for CIP was studied.These results provide a theoretical basis for the remediation of CIP contaminated soil by biochar.The original conclusions of this work are listed as follows:(1)The effects of CMDOM on the adsorption of CIP and Cu2+ onto biochars has been established.The ?-? electron donor-acceptor(EDA)interactions dominantly control sorption strength for CIP onto biochars;The adsorbed Cu2+ on biochar surface could act as a bridge to provide extra sites for attaching CIP via hydrogen bond interaction and thus to increase CIP adsorption,CIP can compete active adsorption sites with Cu2+ or release Cu2+ that adsorbed onto biochars and thus to reduce its adsorption;The solid adsorbed CMDOM facilitated CIP adsorption owing to increase the content of-OH on biochar surface,which could provide more ?-electron donors and thus strengthened ?-? EDA interactions between CIP and biochars,and it also can enhance complexation of Cu2+ with adsorbed CMDOM,thus increasing Cu2+ adsorption onto biochars.(2)A new method was applied in this study to synthesize g-MoS2-BC composites and its adsorption behavior for CIP was studied.The g-MoS2-BC composites prepared in this study showed an excellent adsorption perfo rmance for CIP due to its sharp increase of surface area,appropriate pore structures and abundant ? electrons.It was found that the adsorption of CIP on g-MoS2-BC composites was involved in pore-filling effects,?-? EDA interactions,electrostatic interactions and ion exchange adsorption.