Physico-Chemical Analysis and Aerobic Bioremediation of Paint Effluent Using Pseudomonas aeruginosa and Bacillus subtilis

Abstract

Bioremediation uses biological techniques to reduce the harmful effects of pollutants in   the environment, including wastewater. It is a handy tool for various applications in environmental protection. In developing strategies for bioremediation of paint effluent, untreated paint effluent from Dulux Plc was inoculated with two aerobic microorganisms, Pseudomonas aeruginosa and Bacillus subtilis. Microbiological and physicochemical analysis was carried out for five weeks upon inoculation of effluent with Pseudomonas aeruginosa P, Bacillus subtilis B, in separate setups, effluent sample inoculated with both organisms M, to observe their synergy and  effluent sample without inoculation, served as a control sample to compare the abilities of the  native effluent microflora with that of the introduced microorganisms. The cultures of microorganisms were observed in nutrient broth until the exponential phase before their inoculation into the effluent sample. The bacterial cultures of Pseudomonas aeruginosa, Bacillus subtilis  and consortium contained 4.2 x 108cfu/ml, 3.8 x 109cfu/ml and 5.2 x 109cfu/ml, respectively,   when inoculated into the experimental setups P, B and M, in the experimental samples,  BOD and all the inorganic nutrient sources tested decreased rapidly with a proportional increase  in the population densities. This trend was firm for PO43- and NO3, which eventually became  limiting in the experimental and control samples. Inoculating microorganisms with the addition of appropriate inorganic nutrients may be a suitable method for rapid bioremediation of paint effluent.