Abstract

BIOLOGICAL TREATMENT OF SEWAGE WATER BY HEAVY METAL RESISTANT BACTERIA

Madhulika Chauhan* and Manu Solanki

Abstract

Industrial effluents should be treated for their high BOD before they are discharged into the environment. Most of the inoculated bacteria used for the removal of high BOD are not efficient as they cannot withstand the high concentrations of heavy metals present in the effluents. In the present investigation 20 cellulose degrading bacteria having high resistance to heavy metals were isolated from soil collected from four different sites of industrial area of Faridabad. One heavy metal sensitive bacteria (HMS-1) were also checked for enzymatic activities. Among the 20 isolates, 12 isolates showed higher cellulose reduction activity when compared to other strains varying from 16 to 83%. Further they also exhibited the starch hydrolysis activity varying from 16 to 66%. Finally these isolates were also checked for bioremediation of sewage water and it has been observed that they have the great potential to reduce various parameters such as BOD and COD as compared to HMS-1 strain. The bacterial isolates were screened for metal resistance against Cd, Ni, Pb and Hg. A particular high value of MIC was observed for cadmium ranging from 200ppm to 250ppm. Data indicated that the isolated bacteria have a great potential in organic matter degradation of industrial effluents having high concentration of heavy metals as compared to heavy metal sensitive bacteria.

Keywords: Cellulose, sewage water, heavy metal resistant bacteria, Starch, soil sample, Heavy metals.