Removal of Atrazine by coupling Fenton reaction with bioreactor in series

Abstract

Atrazine is a commonly used weedicide in agriculture fields. Owing to its long half-life (125 days) and slow-biodegradability, it adds to problematic residues in the environment. It is known to disrupt endocrine and reproductive systems and has potential to damage vital organs such as liver, kidney and heart. While atrazine is banned in European countries, many countries, such as India, China, and the USA it is still in use widely. In atrazine biodegradation, batch bioreactors are most commmon cost effective alternative to conventional methods. However, it has only major limitation of slow rate of degradation. In this work, we explored coupling of UV-Fenton and biological method for atrazine removal and also optimized the process parameters. In the bioreactor, Loofa was used as the packing media on which consortia was immobilized. The performance of coupled system was studied with an initial atrazine concentration of 300 mg/L. Overall, maximum removal efficiency of 93% was achieved for the coupled system. GC-MS analysis of residual treated effluent sample was performed to identify the intermediate compound. Two metabolites biuret and urea were identified which confirmed the degradation of atrazine. The growth kinetic parameters <i>µ_max</i> (0.224 per day) and <i>K_S</i> (106.64) were calculated using Monod model. The coupling method was found superior than individual chemical and biological methods for treatment of atrazine.