PERFORMANCE ANALYSES OF A FULL-SCALE RAINWATER TREATMENT UNIT USING DIRECT FILTRATION AND STARCH AS PRIMARY COAGULANT

Abstract

The aim of this study was to investigate the performance of an experimental rainwater treatment system for non-potable uses. Without the first-flush discharge it was expected to control the quality of captured rainwater and to minimize the rainwater by-pass caused by the first-flush strategy. A full-scale direct filtration unit was operated and a solution of natural corn starch was used as the primary coagulant. The color, turbidity e coliform efficiencies of the unit was analyzed based on filtration loads and the net water production was estimated. The results pointed out turbidity removal up to 70.8% and color removal up to 61.0%. The backwash of the filtering system was completed in 3 minutes at the rate of 1,440 m3/m2day with consumption of treated water from 0.5% to 2.2%, based on the potentially harvesting. Keywords: Rainwater, catchment, treatment, utilization, economy.