REDUCTION OF HEXAVALENT CHROMIUM USING BIOFILM FORMING ISOLATES

Abstract

The toxic form of chromium found in industrial effluent which is discharged into the potable water is of high risk for the existence of the life. Removal of this element by indigenous bacterial isolates haven proven to be very effective in treatment of this waste. In this study 3 organisms isolated from different indigenous sources and are tested for the removal of Hexavalent chromium. Batch and column studies were performed for chromium reduction. Batch studies were conducted for 3 isolates with different concentrations of Cr (VI) i.e from 50 mg/L to 1000 mg/L using only nutrient broth and 5% glucose. The isolates were able to survive, resist and reduce in different concentration of Cr (VI). Column study was performed with Isolate 1 for the reduction with an initial concentration of 1000mg/l. The isolate used in sand column reduced more than 50% of the 1000mg/L of Cr(VI). The experiment has shown good results in both batch and column studies. An Initial concentration of 200 mg/L of Cr (VI) was reduced from 95 to 97 % by 3 isolates in batch experiments. The biofilm forming isolates are found to be well fit for heterogeneous sites,which is indicated by the Freundlich isothermal studies.