Using The Fenton Process to Reduce the Volume of the Biological Sludge in Dairy Industries

Abstract

Introduction: Activated sludge is one of the common processes of biological treatment in industrial wastewater treatment plants. In this process, a large amount of sludge is produced which its treatment accounts for a large part of wastewater treatment costs. The aim of study was to investigate the effect of the Fenton process to reduce the volume of the biological sludge in dairy industries.

Methods: This study is an empirical one in which the effect of chemical oxidation process with hydrogen peroxide and Fenton on reduction of produced sludge in dairy industry has been investigated. For this, the effect of pH (1, 2, 3, 4 and 10), [Fe²⁺]/H₂O₂] (0.5, 1, 1.5 and 2), contact time (2 to 12) and hydrogen peroxide concentration (500, 1000, 1500, 2000, and 2500) were studied. All exams have been performed according to the Standard Method book (2005).

Results: Based on the results, the highest VSS removal rate was 82% which was obtained at contact time of 6 hours, pH of 3 and [Fe²⁺]/[H₂O₂] of 1 and hydrogen peroxide concentration of 1500 mg/l. Based on the results, in the absence of Fe²⁺ ion in, the removal efficiency of the system was zero and the highest VSS removal rate was obtained at [Fe²⁺] / [H₂O₂] of 1. Also the amount of VSS decreased with increasing hydrogen peroxide concentration.

Conclusion: The results showed that the Fenton process is a possible and effective option for reducing sludge volume in dairy industries and its application improves the quality of the sludge and stabilization process and facilitates operational conditions.