Drinking Water, Reservoir Water Purification Systems, Case Study Putatan/Philippines

The 100,000 m3/d Maynilad Putatan Water Treatment Plant is the largest water treatment plant in the Philippines based on microfiltrationMicrofiltration (MF) and reverse osmosisReverse osmosis (RO). It is also the first facility to use Laguna Lake as the raw water source. During the operation of the plant, several problems were encountered on the treated water quality due to high fluctuating levels of ammonia and total organic carbon (TOC)/assimilable organic carbon (AOC) and turbidity levels from the Laguna Lake. These problems reduced the life of the MF/RO membranes, thus increasing the chemical cleaning frequency and the consequent operating costs. WABAG proposed to conduct a pilot testing for a biological aerated filter to address the issues regarding the AOC, ammonia, and turbidity levels. WABAG, after successful demonstration of the process with the pilot plant, was later awarded the project for the realization of a full-scale biological aerated filter plant along with upgradation – rehabilitation of the other upstream process units in the existing plant. The project was carried out in two phases with the following scope of works: installation of a biological aerated filterBiological aerated filter (BAF), modification of the dissolved air flotationDissolved air flotation (DAF), and expansion of the plant capacity up to 150,000 m3/d by addition of ultrafiltrationUltrafiltration (UF).