Ceramic membranes trialled in Singapore for seawater reverse osmosis pre-treatment
Ceramic membranes may have historically struggled in the municipal drinking water market compared to its polymeric bigger brother, but Singapore is hoping to change that...
Ceramic membranes may have historically struggled in the municipal drinking water market compared to its polymeric bigger brother, but Singapore is hoping to change that.
Asia’s water hub was one of the first nations to trial the technology, with a S$5 million demonstration plant at the national water agency PUB’s Choa Chu Kang waterworks.
With membranes supplied by Japanese company Metawater and working with Dutch water company PWN Technologies, PUB ran the 1200 m3/day plant for 18 months.
Positive data from this trial led to the technology being adopted in the UK by utility Southern Water in 90,000 m3/day plant to treat reservoir and river water (read WWi story).
Singapore is now trialling the membranes but for use in pre-treatment for seawater reverse osmosis (SWRO) at PUB’s R&D facilty in Tuas for a period of four months.
This latest trial will involve a pilot plant with a capacity of 200 m3/day using just a single ceramic membrane of 25 m2 filtration area.
The membrane will again be supplied by Metawater, working with PWN Technologies and Indian water treatment company, VA Tech Wabag.
Objectives of the trial are:
1. To produce enough data to determine initial optimal flux for stable conditions, and show stable and reliable operation, with minimal down-time and consistent treated water quality;
2. To determine the filtered water quality (e.g. SID, turbidity, metals, organics) and its suitability for downstream RO treatment.
Despite claims of durability and ability to outlast polymeric membranes, a higher CAPEX cost has meant ceramic membranes have traditionally been used more for industrial water production, rather than municipal where they have only a 2-3% market share (read WWi article).
To address this, PWN Technologies - as part of its CeraMac technology – is bundling nearly 200 membrane vessels together, which it claims allows operators to enable an increased backwash of up to 5 bar (read WWi article).