CHENNAI: With rising demand and increasing water scarcity, the only source of water is the sea, sewage and industrial waste water, which have to be treated, reused and managed without harming the environment, said Rajiv Mittal, Managing Director and Group CEO VA Tech Wabag, an Indian Multinational Water Technology Company. He was delivering the T S Narayanaswami Memorial Endowment Lecture at Alagappa College of Technology on Thursday.
Mittal termed seawater, sewage and industrial water ‘difficult water’. “It is difficult because we have to give extra treatment to make it readily acceptable for drinking and potable purposes,” he said. Managing such difficult water is a challenging task for chemical engineers as they have to develop cost effective methods make it eco-friendly.
He spoke about five strategies to ensure water security, which include- making rain water harvest mandatory, interlinking of rivers, promoting recycling and reuse of water, setting up of desalination plants and creating awareness on the need for judicious use and conservation of water and to educate people for positive mindset that ‘difficult water’ is a resource and not a liability. Desalination is a viable, reliable, sustainable and affordable alternative source of water.
Complimenting the Tamil Nadu government on setting up two 100 mld (million litres per day) desalination plants at Minjur and Nemmeli making Tamil Nadu the ‘Desalination capital of India’, he said. “Chennai will get another desalination plant of 150 mld. This will come up on the vacant space in the same premises where the existing 100 mld Nemmeli plant is located. It was also recently announced that the fourth desalination plant will be set up at Perur close to Nemmeli.
The Perur facility will be the largest among the four plants with 400 mld capacity,” he said. The Tamil Nadu government has planned two more such projects at Ramanathapuram and Tuticorin district. All these projects will enable supply of high quality drinking water that would be available even during the dry period, he said.
While there is acceptance on water reuse for industry, it is not readily accepted when it comes to potable purposes.
Namibia has been using direct potable reuse water for more than 15 years and nobody has fallen sick so far. “This was designed, built and operated by Wabag. Technology is not the issue, but the real challenge is public acceptance,” he said. Giving some more examples, he said Chennai Metrowater had adopted sustainable water strategies like water recycle and reuse. It has also come up with supplying treated waste water to the construction industry. “Chennai Metro Water recently awarded an ambitious water recycle project, based on RO process, to Wabag, to meet the water requirement of industries in and around Oragadam,” he said.