With its breakthrough technology on waterless tanning for leather processing, the Central Leather Research Institute (CLRI) expects to save the rivers from the toxic chromium and sulphates effluents mixed in over 170 million litres of water every day.
The CLRI, part of the Council of Scientific and Industrial Research (CSIR), applied to patent the technology in 2014. It now has a “product” and a “process” for waterless and salt-less tanning, that would save water and the environment.
“To treat one kilogram of animal skin and hide about 50 litres of water is used. It’s required to wash the salts used by the tanners at primary stage to preserve the leather, making the effluents hazardous. With the dry tanning technology this would stop,” B. Chandrasekaran, Director CSIR-CLRI, told IANS.
He said that CLRI offers “Dry Tanning” as a product and another “Waterless Chrome Tanning” as a process, that requires training the tannery workers for using salts for preserving the animal skins at primary processing level.
The CLRI technology uses a conventional drum-tanning method, in which instead of lime and water, a CSIR’s patented additives are mixed. That saves water and also helps reduce the solid waste produced by lime and other chemicals.
“The technology reduces the water effluents by 90 to 95 percent,” said Chandrasekaran.
The CLRI, which is now being approached by leather companies across the globe to procure the technology, has also prepared a detailed project report (DPR) for Kanpur, Uttar Pradesh, where the largest number of tanneries are located in India.
“We have been contacted by several domestic tanneries and a big MNC that had offered Rs2 crore for the this technology,” he said.
Kanpur has over 23 percent of the country’s tanneries and uses about 20 million litres of water every day. Most of this untreated effluent flows out through over 23 major open drains into the Ganga river and are the major cause of its pollution.
“A DPR for Common Effluent Treatment Plants (CETP) for Kanpur is being finalised. The main problem is that only a few tanneries in Kanpur treat the effluents,” he said.
There are also several unauthorised tanneries in Kanpur region and about 100 were closed two years back.
Those operating water treatment plants only give primary treatment to the used water. According to environment activists, there is no proper monitoring of such treatment plants. According to green activists, it is a similar case with the tanneries of Kolkata and Tamil Nadu.