Bio-removal of nickel from electroplating industry

Abstract

Ni (II) has been designated as a priority pollutant by the US Environmental Protection Agency (USEPA) due to its ability to cause mutations and cancer in humans. The risk
associated with soil and groundwater contamination of nickel waste generated by many industries is high, and therefore Ni (II) remediation is of critical importance. It is discharged into the environment through the disposal of wastes from industries like Electroplating industry, metallurgical and metal finishing, textiles and ceramics, pigment and wood preservatives, photographic sensitizer manufacturing, etc. In the environment nickel occurs in divalent and tetravalent forms. Comparative to tetravalent, divalent nickel is more hazardous to the environment. Electroplating industry which commonly use nickel metal for plating process, discharges the effluents into the environment containing Nickel in excess of the maximum permissible limits. According to W .H.O. standards the permissible limits for nickel in effluent is 3mg/l and in drinking water is 0.02 mg/l. Staphylococcus sp. has polyphosphate in its cell, which is responsible for sequestering nickel. Using chemical and biological methods conjointly can decrease the cost of remediating contaminated sites. Microbial reduction of Ni(II), an important aspect of biological remediation, requires the knowledge of microorganisms capable of reducing Ni(II) and the mechanisms involved in the reduction processes. Staphylococcus sp. has polyphosphate in its cell, which is responsible for sequestering nickel. The present study is an attempt to evaluate the bio-removal of nickel from wastewater, which is collected and characterized from an electroplating industry, Coimbatore, Tamilnadu, RSP ,Rourkela. Staphylococcus cultured in the lab is used for the removal of nickel. The overall objective of this study was to investigate the effect of various parameters like pH, inoculum volume, sugar amount, initial nickel concentration on nickel reduction by indigenous soil isolated bacteria isolated from soil contaminated sites.