UV-advanced oxidation process for taste and odor removal – comparing low pressure and medium pressure UV for a full-scale installation in Korea

The Water Treatment Plant (WTP) located in South Korea is a 101,000 m³/d water treatment plant using flocculation/coagulation followed by sedimentation and sand filtration plus a final chlorination step to produce drinking water from a natural reservoir. The seasonal occurrence of taste and odor compounds were driving the need for an advanced treatment step. In 2010 the operator decided to carry out pilot tests to test the possibility of removing this compound with a low or medium pressure ultraviolet-based advanced oxidation process (AOP). The pilot test showed a significant lower electrical energy demand (EED) for the low pressure system (EED = 70 W/m³) compared to the medium pressure system (EED = 144 W/m³) to achieve a 0.5 LOG reduction of 2-methylisoborneol. The results of the pilot trials were the basis for the design of the full-scale system capable of treating up to 4,419 m³/h of drinking water using low pressure lamps.