A centre of technological excellence based in the Indian Institute of Technology in Kharagpur (IIT Kharagpur) has developed technologies focusing on water purification. These have helped deliver clean and safe drinking water as well as aided flood management across several states in the country.
The Centre for Technological Excellence in Water Purification (CTEWP) housed in IIT-Kharagpur has created an efficient, low-cost, nano-filtration-based technology to ensure access to safe and clean drinking water free of heavy metals for 25,000 people in three different locations in Telangana and Andhra Pradesh.
Further, a prototype of a highly-compact vertical modular nanofiltration membrane system designed to remove heavy metals, like iron, from groundwater has been developed by the Membrane Separations Laboratory and the Council of Scientific and Industrial Research (CSIR) Indian Institute of Chemical Technology (IICT), with support from the Department of Science and Technology (DST) Water Technology Initiative (WTI).
The technology has a capacity of 100-300 litres per hour (L/h) and is based on a hydrophilised polyamide membrane. It consists of pumps that force water through a prefilter assembly to remove suspended solids, color, odour, and then spiral wound membrane modules, which separate heavy metals. It delivers purified permeates of total dissolved solids (TDS) devoid of contaminants such as iron, arsenic, or excess hardness. Ultraviolet light is used at the end of the process to disinfect any pathogens that may be present in the tank or pipelines.
In North Guwahati, Assam, the water that children of a primary school would drink was highly contaminated with iron, high chemical oxygen demand (COD), and emanated a foul smell. To remedy this, the government installed a water treatment plant (300 L/h) in the school. The device was developed by IIT-Guwahati and designed and fabricated based on chemical less electrocoagulation technique.
Supported by the DST, the device is capable of treating Total Soluble Solvent (TSS), COD, biological oxygen demand (BOD), iron, and arsenic from contaminated drinking water below the BIS limit. More than 120 students at the school, as well as the 500 residents of the surrounding region, now have access to clean, sanitary water.
The CSIR-IICT’s team has also developed a simple, inexpensive, hand pump controlled by a hollow fibre ultrafiltration system that is easy to operate, has high mobility, occupies less space, and is lightweight. The technology supported by the DST was based on membranes called polyethersulfone hollow fibers. A total of 24 water plants were installed during recent floods in Karnataka, Maharashtra, Kerala, Bihar, Odisha, and West Bengal to provide clean and safe drinking water to 50,000 people.
The pressure generated by the hand pump to transport floodwater into the membrane module facilitates the permeation of clarified and disinfected water through the porous membrane, while a small chlorine cartridge installed at the membrane outlet leaches free chlorine to tackle any secondary contamination.
The solutions by the centre for water-related problems ranging from contamination by heavy metals to flood-related water problems have been comprehensively helping tackle health and disaster management challenges.