India and the European Union have developed a cost-effective technology for treatment of sewage waste for irrigation, especially in rural areas, using natural filters like sand and plants. The project involves collecting the sewage waste before it reaches the water bodies and then treat it using natural filters like sand, gravel, pebbles and plants to remove the impurities. Under the project, many wetland plant species, such as Cannaindica, lemon grass, napier, para grass, typha, water hyacinth, water lettuce and a weed species Agaratum conyzoides, have been identified for purifying the wastewater. They are helpful in reducing the nutrient load in the free-water-surface and sub-surface constructed wetlands. The project has been undertaken in Karnataka,Maharashtra, Telangana, Uttar Pradesh and Madhya Pradesh. This is a cost-effective method to not only use the sewage, but also effectively use the water in rural areas," said Suhas Wani, Project Leader and Director, Asia Region, ICRISAT-- one of the partnering institute in the project from India.
It would cost anywhere between Rs 3 lakh and 5 lakh to build a facility like this in an area housing 2000 people, Wani said.
"We have also written to the PMO if we could integrate this with the Swachch Bharat Mission as it also involves treating of waste water," she added.
The reuse of treated wastewater to irrigate fields has shown increased yields of up to 40 per cent in crops such as okra, brinjal and chilli plant as compared to those irrigated by fresh water.
The 'Water4crops' is one of the largest technology initiatives between India-EU. India has contributed 3 million euros to the project and the EU 9 million euros. The EU consortium includes 21 partners from 8 countries while the Indian consortium has 11 research and development partners led by the International Crops Research Institute for the Semi-Arid Tropics
The project also proved that the construction of wetland reduces the amount of pollutants, chemical oxygen demand (COD) in wastewater by 30-92 per cent.
Based on the pilot sites at the ICRISAT headquarters in Hyderabad and other locations, a total of 28 watershed sites are now supported by various corporates under corporate social responsibility (CSR) projects as well as the Government of Karnataka's Bhoo Samrudhi programme and Andhra Pradesh Primary Sector Mission's (APPSM) Rythu Kosam.
It is also being piloted at a brewery in Medak in Telangana. K Vijay Raghvan, Secretary Department of Biotechnology, Ministry of Science and Technology, however, said the scheme was more effective in rural areas as compared to urban areas because the pollutants involved in urban areas need Sewage Treatment Plants (STPs).
Y S Chowdary, Minister of State, Ministry of Science & Technology highlighted the importance of treated wastewater for addressing the issues of sanitation and health in rural areas as well as water shortage for agriculture to improve livelihood.
Tomasz Kozlowski, the Ambassador of the EU to India said the project is a good example of how top-level research organisations from several European countries and India can jointly develop concrete solutions that benefit both sides.