Low cost adsorbent to reduce disinfection by-products from drinking water in small communities

摘要

Although there are different types of treatment methods such as membrane filtration, coagulation, reverse osmosis and other adsorption processes available to reduce trihalomethanes (THMs) and haloacetic acid (HAAs), and the two major groups of disinfection by-products (DBPs) in the drinking water systems, most of these methods require trained personnel to operate and maintain the system and high capital investment and operating cost. Due to lack of skilled personnel to operate and maintain water systems and also high capital cost, it is not feasible to install such systems in small communities. The main objective of this study is to identify a cost effective adsorbent to remove DBPs and their precursors. The adsorbent developed from oil fly ash residues is available in abundance at very low cost. The adsorbent to be developed by extracting clean carbon can be easily installed and operated in small systems. In this research, the extracted adsorbent is tested with a series of experiments using raw and treated water from the Pouch Cove community near St. John's. The results show a significant removal of DBPs from tap water and precursors such as natural organic matters from intake source causing formation of DBPs after chlorination. The extracted carbon from oil fly ash shows significant removal of THMs and HAAs from drinking water and from the Pouch Cove drinking water supply system. The clean carbon is also used to remove natural organic matter and turbidity from raw water before chlorination.