Removal of Disinfection By-Products (DPBs) By Electro-Coagulation Process in a Continuous Flow Reactor As a Localized Water Treatment Technology

Nowadays, chlorine is commonly used as the disinfectants in water treatment process.  However, it would react with nature organic matter (NOM) to product disinfection by-products (DBPs) such as trihalomethanes (THMs) and Haloacetic acids (HAAs).  The above DBPs presented in drinking water have been considered as toxic materials because they would result in Bladder cancer, rectal cancer, colon cancer and brain cancer according to the laboratory animals.  The standard regulations for THMs in drinking water are 0.1 mg/L in both European Union and Taiwan.  On the other hand, the USEPA formulated the standard concentration for disinfectant-disinfection by-products from 100 ug/L to 80 ug/L and would be further restricted to 40 ug/L in the future.  

Electrocoagulation (EC) is an electrochemical process for treating wastewater by using sacrificial anodes to produce coagulant precursors into solution.  In that case, aluminum ions would be released from the sacrificial anode instead of traditional coagulant, e.g., aluminum salts, thereby increasing the treatment efficiency.  In general, the removal efficiency of EC process for wastewater treatment is depended on the characteristic of wastewater quality and operation parameters.  Therefore, the purposes of this investigation are to (1) evaluate the removal performance of THMs, biochemical oxygen demand (BOD) and suspended solid (SS) in wastewater by applying the continuous flow reactor with EC process, and (2) investigate the effects of different operating conditions including pH values, voltage and electrical conductivity on the removal efficiency of DBPs.