Removal of arsenic from aqueous solution using pottery granules coated with cyst of Azotobacter and portland cement: Characterization, kinetics and modeling

Abstract

A new low cost adsorbents, pottery granules coated with cyst of Azotobacter and portland cement has been developed for aqueous arsenic removal. The developed granule is solid and porous structure forms a stable complex of Fe-Al-Si-O2 allied with cyst biomass. Batch experiments were revealed that As removal was up to 96% using PGAC beads, whereas 65% by cyst biomass. Immobilization of cyst biomass to pottery granules through portland cement improved the stability of granules and adsorption capacity. Kinetics studies revealed that Langmuir isotherm was followed with a better correlation than the Freundlich isotherm and adsorption was first order diffusion controlled. Presence of Fe-Al-Si-O2 and polysaccharide complex on the granule surface may be responsible for the adsorption of arsenic and preferentially binds to biomass containing composite than only biomass. Thus, this recently developed cost-effective novel biocomposite, PGAC granule can be used as household level to mitigate the arsenic problem. © 2011 Elsevier Ltd.