New entry point of membrane technology for public water treatment plants in Malaysia

Abstract

Membrane applications in public water treatment plants (WTP) in Malaysia have seen more setbacks than successes. Its early applications in a few locations encountered operational problems which saw many systems cease operations due to high operating expenses, membrane fouling or poor raw water quality. The main issue, however, was financial-related in view of the fact that the water tariff has been regulated and heavily subsidised. Both capital expenses (CAPEX) and operating expenses (OPEX) have not been affordable within such a framework. The power consumption of a 3 million L d-1 (MLD) hybrid membrane WTP subjected to study consumed 1.5 kWh m-3 of electricity as compared with 0.43 kWh m-3 for a conventional system in the same district. Besides that, cartridge filters had to be changed on a weekly basis as compared with filter media which can last more than 5 years. Capital cost of a membrane WTP is at least twice more expensive than conventional systems. Based on the standard of raw water adopted in the Malaysia, it is imperative that operators raise raw water quality standards prior to treatment whether through natural process or forced, physically or chemically. Downstream reservoir, river bank infiltration and radial well system have been applied in several projects in Malaysia and had successfully resulted in the high quality of raw water. However it has always been restricted from being implemented holistically due to financial constraints. Hybrid offriver storage implemented as interim measure to improve raw water quantity had indicated prospect of improving raw water to reach higher standards. This paper compares the raw water quality of various non-conventional raw water abstractions, followed by discussion on the proposed entry point of membrane systems in Malaysia for public WTPs.