Synthesis of reactive iron impregnated nanoporous activated carbon and its application in anaerobic biological treatment to enhance biodegradability of ortho-phenylenediamine

BACKGROUND O‐phenylene diamine (OPD) is a bioresistant and endocrine disrupting chemical. Fenton oxidation can partially degrade OPD, but the products formed are more bioresistant than OPD. The main objective of the present investigation is to create a novel integrated IINPAC‐H2O2 oxidation system followed by anaerobic biological treatment to destroy OPD in aqueous solution. RESULTS IINPAC‐H2O2 oxidation (pre‐treatment method) was attempted with the prepared iron impregnated nanoporous activated carbon (IINPAC) catalyst and degradation studies were carried out at optimum conditions, hydraulic reaction time 120 min; pH 7; H2O2 1.76 mmol/L−1; IINPAC 0.2 g L−1 and OPD 2000 mg L−1. The biodegradability index (BOD5/COD) of OPD was increased from 0.1 to 0.45 under optimum conditions. The IINPAC‐H2O2 treated effluent was further treated in a fluidized anaerobic reactor using Enterococcus faecalis sp. (GenBank: KF656727). CONCLUSION The integrated catalytic IINPAC‐H2O2 oxidation system and anaerobic biological treatment process removed 98.45% of COD and 79% of BOD5. Stability and reusability tests of IINPAC showed that it could retain its catalytic activity even after 15 cycles. © 2014 Society of Chemical Industry