Studies on Removal of Nitrobenzene from Contaminated Water and Sediment by Bioaugmentation

Nitrobenzene is highly toxic liquid aromatic compound which is readily absorbed through the skin. Although nitrobenzene is not currently known to be a carcinogen, prolonged exposure may cause serious damage to the central nervous system, impair vision, cause liver or kidney damage, anaemia and lung irritation. Natural attenuation, biostimulation and bioaugmentation of nitrobenzene contaminated sediments were investigated and compared. The removal rate of nitrobenzene from contaminated environments with bioaugmentation was much faster than with biostimulation and natural attenuation. Within 10 days, 8 mg/kg and 56 mg/L nitrobenzene in sediment and water, respectively, were degraded with the augmentation of Pseudomonas putida isolated from the contaminated sediment. There was no distinct performance difference between natural attenuation and biostimulation, demonstrating that addition of nutrients had no effect on the bioremediation process. The information on the current phase is a crucial step in making policy decisions for the application of bioremediation.