Denitrification and removal of heavy metals from waste water by immobilized microorganisms

Abstract

Pseudomonas fluorescens, immobilized on soft polyvinyl chloride granules containing up to 35% softeners as carbon source, was used for simultaneous removal of nitrate and heavy metals. In typical continuous column operation, a 100 mg/L nitrate input solution was reduced to a 20 mg/L output at a feeding rate of 1500 mL/h, with a capacity of 14 kg/day/m³, and with an efficiency of 79%. In the same column, Pb(NO₃)₂ concentration was reduced from 1.0 to 0.05−0.1 mg/L and ZnSO₄ concentration was reduced from 10 to 5 mg/L.Pseudomonas aeruginosa immobilized on an O₂ plasma-treated melt blown polypropylene web was used for removing 95% of a 1.7 nCi PuCl₄ activity from a nuclear plant waste water in a batch operation.