Investigation in UV/Fenton treatment of black liquor

Abstract

This is an investigation in ultraviolet (UV) Fenton treatment of black liquor after paper-making. UV/Fenton is an innovative method in chemical plant and also needs SGF-1 multi-function instruments and a biochemical oxygen demand (BOD) determination instrument to test the data. In this study, the degradation of black liquor by UV light assisted Fenton-like process (Fe2+ /H2O2/UV-A) was investigated at different pH values. The effects of different process variables such as the initial Fe2+ and H2O2 concentrations, reaction time, and UV-A light on black liquor, COD removal were evaluated as well. Chemical oxygen demand (COD) and 5-day biochemical oxygen demand (BOD5) were selected as the environmental sum parameters to follow the performance of Fenton-like and photo-Fenton-like advanced oxidation processes (AOPs) on the black liquor. At optimum reaction conditions, 79.14% COD removal was achieved by the photo-Fenton-like process. Another advantage of the UV-A light-assisted Fenton-like process is the BOD5/COD ratio increased after application of the photo-Fenton-like processes. Based on the results of above experiments, it could be inferred that the photo-Fenton-like process is a suitable method for partial mineralization of black liquor.