Remediation of cefdinir from aqueous solution using pretreated dead yeastCandida sp. SMN04 as potential adsorbent: An equilibrium, kinetics andthermodynamic studies

摘要

Cefdinir, a semi-synthetic third generation cephalosporin antibiotic being considered as an emerging pollutant which demands removal from environment. This work represents the biosorptive removal of cefdinir from aqueous solution using dead biomass of Candida sp. SMN04 as an adsorbent. Batch adsorption studies were conductedto determine the effect of various parameters viz. pH, biosorbent dosage, contact time and initial cefdinir concentration during cefdinir adsorption. The adsorbent was subjected to various pretreatments. The pretreatment with succinic acid showed maximum cefdinir removal of 81.0% compared to other pre-treatments. Among the various isotherms tested, Langmuir model fitted best showing maximum adsorption capacity 238.09 mg/grepresenting monolayer and homogeneous mode of adsorption, which was confirmed by SEM analysis. The kinetic data were found to follow pseudo-first order model suggesting physisorption as an underlying mechanism. Thermodynamic studies showed that the adsorption process was exothermic and spontaneous in nature. FT-IR analysis showed the involvement of functional groups viz., hydroxyl, carboxyl, amine and sulfide groups during cefdinir adsorption. Based on the results, it may be concluded that, the dead biomass of Candida sp. SMN04 can serve as potential adsorbent for the removal of cephalosporin antibiotics from aqueous environment.