Abstract: Electrochemical method was used to pretreat the nitrobenzene containing wastewater. A set of orthogonal experiments was carried out to study the influencing factors. Test results showed that under the optimum conditions of an electrolysis voltage of 15 V, an electrolysis current of 0.30 A, a pH value of 3 and a reaction time of 50 min, the removal rate of nitrobenzene was 100%. The pretreated wastewater was easy to be biodegraded. By treating with microorganism for 14 h, the removal rates of aniline and COD reached 99.5% and 82%, respectively. After 18 h biodegradation, the COD removal rate could reach 94%, indicating that most of the organic compounds in the wastewater were biodegraded to CO2 and H2O.

Key words: electrochemistry, nitrobenzene, orthogonal experiment, electrolysis mechanism, co-biodegradation