Kinetic analysis of coupled attenuation of nitrobenzene by microbial dissimilatory iron reduction in groundwater

Abstract

Coupled attenuation system consists of iron oxides, electron donor and iron reducing bacteria. The reaction rates would be influenced by the change of any related factors. Steady state experiments were performed to investigate coupled attenuation of nitrobenzene by microbial dissimilatory iron reduction. The removal efficiency of nitrobenzene(50mg/L) was up to 78.5% while the concentration of goethite at 0.3g/L in 100 hours; In the presence of 10 mmol/L electron donor, ammonium acetate, ammonium citrate and glucose control system, the reducing efficiency of nitrobenzene(50mg/L) reach 78.5%, 74.8%, 70.0% and 69.3%, respectively. Obviously, ammonium acetate was the dominant electron donor and nitrobenzene could be utilized by iron reducing bacteria significantly; At microbial concentration gradients was 0.5−8.0×10 <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">8</sup> cells ml <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">−1</sup> ,the reduction of nitrobenzene present a peak at 4.0×108cells ml <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">−1</sup> . These results provide an evidence of coupled attenuation of organic pollution by microbial dissimilatory iron reduction.