Comparison of Coal-, Coconut-, and Wood-Based Activated Carbons for Removal of Organic Matters in Wastewater Treatment Plant Effluent

Abstract

Objectives : This study investigated the removal of dissolved organic materials by coal-, coconut-, and wood-based activated carbons to assess the addition of an activated carbon process to a publicly owned treatment works (POTW).Methods : We assessed the removal of total organic carbon (TOC) by each process in the POTW, and examined the removal of TOC and UVA254 upon adding different amounts of coal-, coconut- and wood-based activated carbons (50, 100, 200, 300, and 400 mg/L) with various contact time (10, 20, 30, 60, 120 min).Results and Discussion : Approximately 80% of TOC was removed throughout the POTW compared to the influent. The activated carbon adsorption tests of coagulated wastewater revealed that the removal rate of TOC and UVA254 from coal-based activated carbon was higher than those of coconut-based and wood-based activated carbons. The removal rate of dissolved organic materials was highest in ozone treated wastewater in all types of activated carbons, followed by ultraviolet disinfected wastewater and coagulated wastewater.Conclusions : It was possible to remove an additional 35-55% of dissolved organic materials upon addition of activated carbon to the treated wastewater although the removal depends on the material of the activated carbon, the injection amount, and the contact time. If an activated carbon process is adopted to the POTW, it can meet the effluent water quality standards (TOC).