Conversion of Waste Materials into Heterogeneous Oxidation Catalysts for Treatment of Chlorinated Organics

Abstract

Waste disposal is a challenging environmental concern worldwide. Carbon-rich waste materials can be transformed into adsorbent and/or catalyst support to reduce treatment costs and promote waste recycling. In the present study, three waste materials—sewage sludge, black liquor (from pulp and paper mills), and sugar mill press mud—were converted into activated carbons which were used as support for the iron-impregnated heterogeneous Fenton-type photo catalysts. These materials were characterized and tested on synthetic wastewater containing 4-chlorophenol (4-CP) as the model compound and simulated pulp-bleaching effluent. The oxidation runs were performed at an initial reaction pH of 4.4 with stoichiometric H2O2 dose and catalyst mass loading of 1 g/L for 2 h duration. The maximum total organic carbon removal of 69% and 32% was observed for 4-CP and simulated bleaching effluent, respectively, during photocatalytic oxidation with black liquor–derived catalyst. Thus, the use of black liquor–derived catalyst for bleaching effluent can help paper mill operators handle liquid as well as solid waste in a very efficient manner.