Treatment of high-strength wastewater by Fe²⁺-activated persulphate and hydrogen peroxide

Abstract

Ferrous ion-activated persulphate and hydrogen peroxide were studied for the treatment of real high-strength industrial effluent. The Fenton process demonstrated greater organic load removal, biodegradability improvement and toxicity reduction as well as lower treatment cost than the activated persulphate system. However, the use of an activated persulphate process was more favourable due to the exothermic effect intrinsic to the Fenton reaction, which resulted in a rapid increase in the temperature of the high-strength wastewater along with excessive foam formation. Overall, for the H2O2/Fe(2+) and [Formula: see text] processes, the application of a chemical oxygen demand (COD)/oxidant/Fe(2+) weight ratio of 1/0.4/0.075 resulted in a COD removal of 58 and 50%, a 7-day biochemical oxygen demand/COD ratio increase from 0.14 to 0.3 and 0.23, and an increase in the EC50 (Daphnia magna) by 6.5-fold and 2.9-fold, respectively. The stepwise addition of the oxidant and activator was favourable for the Fenton process and resulted in negligible improvement in the wastewater treatment efficacy in the activated persulphate system.

Treatment of dye-producing chemical industry wastewater by persulfate advanced oxidation

“…Advanced oxidation technologies are suitable and effective method for the treatment of high nonbiodegradable and persistent organic pollutants in industrial wastewaters [5]. Although hydroxyl (OH •− ) production processes such as Fenton and UV photocatalysis oxidation processes have been used as advanced oxidation processes for many years, interest in the persulfate oxidation processes for producing the sulfate radical has increased for persistent organic pollutant removal in recent years [6].…”