Acidogenic biotreatment of wastewater containing 2-nitroaniline and copper

Abstract

In the present study, laboratory investigations were carried out to evaluate the feasibility of acidogenic pretreatment of wastewater containing 2-nitroaniline and copper. The experiments were conducted using Anaerobic Toxicity Assay (ATA) Test, Anaerobic Sequencing Batch Reactor (ANSBR) and Aerobic Inhibition Test. From the experimental results, it was found that acidogenic biotreatment process could remove 2-nitroaniline effectively. Metabolites were identified as 2-methylbenzimidazole and o-phenylenediamine. Copper inhibition on bacterial activity was estimated by considering volatile fatty acids (VFAs) production. Propanoic acid was most severely affected followed by pentanoic acid, butanoic acid and ethanoic acid with increasing concentrations of copper. The removal of 2-nitroaniline was observed to be around 90 % and 78 % when the copper concentrations were 0 mg/L and 25 mg/L respectively with acclimated biomass in the ANSBR track runs. The acidogenic process could be, therefore, an attractive alternative for upgrading present aerobic treatment processes which are not so effective in removing persistent organic compounds from industrial wastewaters.