PUB trial aims to halve energy used to pre-treat seawater for desalination

Singapore is conducting trials on a new method to prepare seawater for desalination, which could potentially cut the energy used in the pre-treatment process by half. The technology being tested is ceramic membrane technology developed by Japanese firm Meiden. Currently, removing contaminants from seawater involves three stages, but the new system aims to combine these stages into a single, more compact step.

Dr Gurdev Singh, PUB's chief engineering and technology officer, stated that this could allow for producing water at the same high quality with much less energy and a smaller footprint. The trial, which began in June and will run for about six months, uses 24,000 sheets of ceramic membrane and has the potential to produce up to 6 million gallons of filtrate water per day.

The system works by seawater flowing over the porous ceramic sheets, where channels draw water through the membrane, trapping contaminants such as dirt, algae, and grease. Meiden claims that their ceramic membranes are more robust than conventional polymeric membranes and can handle challenging seawater conditions, including algal blooms and oil spills.

PUB believes that the durability of ceramic membranes can help make Singapore's water treatment processes more resilient in the face of climate change and potential incidents at sea. While ceramic membranes are more expensive to install, their longer lifespan could offset the higher upfront cost, potentially generating savings within a decade.

The trial is part of a broader effort by PUB to reduce energy and land requirements for water production while strengthening the resilience of Singapore's water supply.