THM Reduction Feasibility Study for the Water Treatment Plant at the Town of Rainy River- Ion Exchange Process with Regeneration

点击翻译按钮获取中文摘要

In Manitoba, nearly 70% of potable water treatment plants exceed the standard for the potentially carcinogenic chlorine disinfection by-products - trihalomethanes (THMs). THMs are formed when chlorine reacts with water Dissolved Organic Carbon (DOC), therefore, quality and quantity of water DOC will affect how much THMs are formed. Elevated level of THMs is a major concern for the Town of Rainy River (Ontario). The water treatment plant in Rainy River recorded elevated THMs levels in the distribution system often exceed 100 ppb with a maximum reading of 233.3 ppb in July 2010. The current Guideline for Canadian Drinking Water Quality (GCDWQ) has a THM regulation of 100 ppb which is expected to be lowered to 80 ppb in the near future following the United States Environmental Protection Agency (USEPA). DOC is typically removed by chemical coagulation, but, the efficiency of this process is quite low. In this project we aim to investigate the removal of DOC from the Rainy River using an Ion Exchange Technology. This is a relatively new technology and there are no publications describing effectiveness of this technology on the surface waters with extremely high DOC typical for the Canadian Prairie and the Shield. Two anion exchange resins will be tested; both resins are strong base anion exchange resins that can be used to remove organic acidic ions from water. The laboratory test conditions producing treated water with the lowest concentration of chlorine disinfection by-products (THMs) will be recommended to KGS for further testing in the pilot scale studies. This research will study the possible methods for improvement of removal of water DOC at the existing water treatment process at the Town of Rainy river. This study will provide KGS with the strategies to optimize the operations of the existing water plants, and allow for avoidance of costly plant upgrades which provide significant savings to the community. Many communities supplied with high DOC waters, common in the Canadian Prairies and the Shield, will benefit from this study.