STUDY ON PHOSPHORUS REMOVAL USING A NEW COAGULATION SYSTEM

In this study, the conditions for coagulation and filtration to gain h igh phosphorus removal efficiency were investigated with a coagulation -filtration phosphorus removal system and its practicability was confi rmed. Sand of 0.6 mm in diameter, anthracite of 1.2 mm in diameter and a mixture of both were examined as a filter media, and the dual filte r bed proved to be superior in the aspects of pressure drop and breakt hrough. This system can be operated continuously for over 20 hours. A blocked filter bed can be recovered by backwashing. Over 80% phosphoru s removal efficiency is achieved at an LV of under 5.0 m.hr(-1). when the PAC dose is controlled so that the Al/P mole ratio would be 3.0 fo r the first period, and then subsequently around 2.0. Flocs caught in the filter further adsorb the soluble phosphorus in the wastewater, th us the chemical requirement can be reduced compared to the chemical pr ecipitation method.