Degradation of Lindane by persulfate/ferrioxalate/solar light process: Influential operating parameters, kinetic model and by-products

Abstract

This work describes the removal of lindane by persulfate activated with ferrioxalate under simulated solar light irradiation and circumneutral pH conditions. The influence of the main operating parameters is evaluated, and a kinetic model based on a radical mechanism is proposed and validated. To do this, synthetic solutions polluted with lindane and different amounts of oxidant and catalyst were employed. Results show that it is possible to completely remove lindane in 300 min using 2.29 mM persulfate and 0.12 mM ferrioxalate. Furthermore, chloride mineralization higher than 90% is achieved under these conditions. On the other hand, the main intermediate organic compounds are identified, and a degradation pathway based on the formation of sulfonated organics is proposed. Finally, the kinetic model proposed fits well with the experimental results and can help to predict the degradation of lindane in more complex effluents and under different operating conditions.