CERAMAC~?-19 DEMONSTRATION PLANT CERAMIC MICROFILTRATION AT CHOA CHU KANG WATERWORKS

摘要

Ceramic membrane technology is known for its robustness of the ceramic membranes, butceramic membrane systems have historically been too costly for installation in drinking watertreatment plants, primarily due to the traditional configuration of each membrane module beinghoused in individual stainless steel casings, which is costly. PWN Technologies (PWNT) hasdeveloped a different ceramic membrane system configuration, called the CeraMac? whichgreatly reduces the capital cost by housing up to 200 modules in a single, stainless steel vessel.PWNT, together with PUB, Singapore's National Water Agency, has embarked on a rigorous andsystematic evaluation of the newly developed CeraMac? system at the Choa Chu KangWaterworks (CCKWW). The demonstration plant testing began with coagulated and clarifiedfeed water from the existing CCKWW. The findings of this phase of testing were that theCeraMac? system can operate with a flux of 200 lmh, a backwash interval of 30 minutes, and anenhanced backwash interval of once every 30 backwashes when treating clarified water.Membrane permeability was stable at approximate 325 lmh/bar at a water recovery of 96.88%.In this phase, fluctuations of transmembrane pressure (TMP) and permeability were alsoobserved, mainly owing to changes in feed water quality. In a second phase of the demonstrationstudy, ozone was applied to the clarified feed water to investigate the effect on membraneoperational performance. The results of these tests exceeded expectations. The combination ofozone with CeraMac~? significantly improved the system's performance, with stable operation,lower TMP, increased permeability, and increased recovery. The CeraMac? system operatedwith a flux of ＞240 lmh, a backwash interval of 180 minutes, and an enhanced backwash intervalof once every 4 backwashes when treating ozonated clarified water. A membrane permeability of850 lmh/bar and a water recovery of 99.3 % were achieved. This flux was the maximum thatcould be achieved by the equipment that was installed in the demonstration plant.