Anoxic biodegradation of a surrogate naphthenic acid coupled to reduction of nitrite

Batch experiments revealed the optimum temperature as 24 ± 2 °C and that the nitrite inhibitory effect was severe at 1150 mg nitrite L−1. Maximum biodegradation rates in the stirred tank and biofilm reactors were 14.4 and 82.2 mg L−1 h−1, and the corresponding nitrite reduction rates were 44.2 and 361.6 mg L−1 h−1, respectively. Using the experimental data, maximum specific growth rate (μm), saturation constant (Ks), and yield (Y) were determined as 0.4 h−1, 20.9 mg trans-4MCHCA L−1, and 0.3 mg biomass (mg trans-4MCHCA)−1, respectively. Comparison of anoxic biodegradation results with nitrate and nitrite demonstrated the superiority of nitrate as an electron acceptor for anoxic biodegradation of NAs.