The Potency of Fenton-Polyaluminum Chloride for Black Liquor Treatment

Abstract

Black liquor is one of the main by-products of the pretreatment process in bioethanol production from empty oil palm fruit bunches, with a high chemical oxygen demand (COD) and low dissolved oxygen (DO). The effect of FeSO4 as a coagulant and FeSO4–H2O2 for Fenton on the degradation of black liquor was examined. This study also identified the ability of a fungus to decolorize black liquor wastewater after the Fenton process and on original black liquor. One percent ferrous sulfate decolorized 84% of black liquor with a concentration of 30,000 ppm under the coagulation method. By adding H2O2 and FeSO4 through the Fenton process, decolorization of the original black liquor was approximately 52%. Combining Fenton and polyaluminum chloride decolorized black liquor up to 90% in 33 min, whereas Coriolus versicolor decolorized 54% and 75% Fenton-treated black liquor and original black liquor after 15 days, respectively.