The Indo-Asian News Service reported that scientists are warning that rampant use of reverse osmosis (RO) filtration technology could pose a serious threat to public health in India.
One of the most popular water purifying technologies in India, the RO process is efficient in filtering out toxic substances like arsenic and fluoride, especially in areas where groundwater is heavily contaminated.
RO systems, especially those used in bottled-water manufacturing plants, dump concentrated amounts of these substances back into the aquifers.
Experts suggest that regulations may be needed to stop disposal of the waste left behind after filtering.
“What we found with our survey is that industrial firms, like bottled-water ones, have no way out but to put it back into the soil and aquifers,” said Saradindu Bhaduri, Assistant Professor, Centre for Studies in Science Policy, School of Social Sciences at Jawaharlal Nehru University (JNU).
The waste water generated by RO systems could have adverse consequences after it is dumped back into the groundwater aquifers, he told IANS.
“The waste water contains high amount of total dissolved salts like sulphates, calcium, bicarbonates and organic matter and higher concentration of arsenic and fluoride in areas where originally these elements were reported in ground water,” co-author of the study, Aviram Sharma of the JNU, said.
Published on April 25 in Current Science, the survey report titled ‘Growth of water purification technologies in the era of regulatory vacuum in India’ also questions the absence of proper methods to dispose of the contaminated waste water.
The research shows that bottled water firms of all sizes and classes, ranging from major multinationals to the vast majority of India’s 2,700 small proprietary firms, use RO-based water purification technologies in their manufacturing plants.
During industrial use, waste water accounts for 30-40 percent of the total water used. This can impact water-starved areas due to over extraction of ground water, which is a major source of fresh water in most of the regions in India, said Sharma.
Namit Bajoria, Director of Kutchina, manufacturers of consumer-based RO system in India, says “We have regulations for water quality but we don’t have regulations for the application of these processes.”
Bajoria also said that more studies were needed.