Importance of the order in enhancing EfOM removal by combination of BAC and MIEX®

Biological activated carbon (BAC) is operationally a simple treatment which can be employed to remove effluent organic matter (EfOM) from secondary wastewater effluent (SWWE). Unfortunately, BAC removes only a limited amount of dissolved organic carbon (DOC). Thus, maximizing DOC removal from SWWE using BAC is a major concern in wastewater reuse. This study has investigated a hybrid system of BAC and Magnetic Ion Exchange Resin (MIEX®) for the enhanced removal of DOC. Performance of both BAC prior to MIEX® (BAC/MIEX®) and reverse (MIEX®/BAC) combination was evaluated in terms of DOC removal. The BAC/MIEX® showed much better DOC removal. This is because microbial activity in the BAC bed converted MIEX® non-amenable DOC to MIEX® amenable DOC. As a result, BAC/MIEX® combination synergised DOC removal. In addition, BAC was also found to be highly effective in reducing MIEX® dose for a given DOC removal from SWWE.