THE INVESTIGATION OF THE ADVANCED TREATMENT OF MUNICIPAL WASTE-WATER BY MODULAR FLOTATION-FILTRATION SYSTEMS AND REUSE FOR IRRIGATION

The objective of this study was to provide clarified municipal wastewa ter effluent at the turbidity level of less than 2.0 NTU and reuse for landscape irrigation (golf course). For that purpose, during pilot-st udy first was used a combined flotation-filtration module-clarifier al one (Alternative I). A particularly designed configuration of the prim ary flotation unit and combined flotation-filtration clarifier, as a m odular clarification system was used in the next step of the investiga tion (Alternative II). In addition, start up of the full scale plant w as performed as well, In the first phase of this study, the impact of the type and concentration of coagulant and flocculant was tested. As a result, mechanisms of flocculation were proposed, Only under the mod erate hydraulic loads (75.7-151.4 LPM) during pilot tests by Alternati ve I, was it possible to reach satisfactory turbidity reduction. By th e Alternative II, the clarification performance was improved under the higher hydraulic load (302.8 LPM). The kinetics of the investigated f lotation systems were assesed by empirical flotation models, Based on the pilot-study, Alternative II is recommended in order to reduce the high solids loadings under a higher hydraulic load, and it provided ir rigation water at a required rate of 3785 m(3)/d during start up and o ptimization of the hill scale plant. Copyright (C) 1996 IAWQ.