Singapore to recycle and desalinate water

K S Jayaraman Singapore, Nov 25 (PTI) A water filter technology developed by an Indian government laboratory in Hyderabad is set to play a significant part in Singapore's efforts to supply clean water to its three million people. Singapore which consumes 300 million gallons of water per day depends on Malaysia for almost half its water requirement. It is seeking to reduce its dependence on its neighbour by recycling wastewater and desalinating seawater. A stainless steel water filter developed at Advanced Research Centre International (ARCI) for Powder Metallurgy in Hyderabad is expected to contribute to this effort. ARCI is run by the Indian Department of Science and Technology. It has transferred its technology to Hyflux Limited of Singapore -- a young and dynamic company that is already offering products and services in raw water treatment, purification, wastewater treatment and water recycling to industries in Singapore and China. ARCI's technology in stainless steel filters is being taken up in our committed program on water treatment, a senior official of Hyflux said in a telephone interview. He said his company would shortly start manufacturing these filters in-house using the Indian technology. R Sundaresan, Deputy Director of the Hyderabad lab told PTI that the process being transferred to Hyflux covers production of long, slender stainless steel porous tubes made by cold isostatic pressing followed by sintering in vacuum or under hydrogen.

The pores in these filters are so tiny they can filter off particles (or microbes) as small as five micrometers or five thousandths of a millimeter, he said. Much of the raw water treatment in Singapore is currently based on separation technology using polymer membranes, while wastewater treatment calls for more rugged stainless steel filters. Apart from being rugged, stainless steel offers a possibility to clean, with appropriate solvents, thereby prolonging the life of the filter, unlike membranes, which have to be discarded, Sundaresan said. The Hyflux official said sintered stainless steel porous parts developed at ARCI have the distinct advantage of higher resistance to corrosion and heat. He said that his company will have to carry out further research and development work before the ARCI filters can be turned into a commercial product. Singapore and Malaysia have long bickered over the water supply agreements signed in 1961 and 1962. Malaysia that is selling its water to Singapore at 3 sens (Rs.4) per 1000 gallons is asking for a price review but Singapore says Malaysia has no legal right for price revision. To reduce dependence on Malaysia, beginning next year, Singapore government intends to mix two million gallons a day of recycled water -- dubbed NEWater -- with water in reservoirs before being treated and piped to homes. The island state has built two water recycling plants and will build two more to meet the target of producing 55 million gallons a day of NEWater by the time the first contract with Malaysia expires in 2011.