The CSIR has filed a patent for its breakthrough in leather tanning technology that does not require water.
The research carried out at CSIR-Central Leather Research Institute (CSIR-CLRI) is aimed at providing multiple benefits relating to in-process abatement of effluent problem, curtailing process steps, conservation of time and money.
Conventional chrome tanning process, which used chromium sulphate, is highly water intensive and requires around 45-60 million litres of water every day. Chemicals used in this process are also highly toxic in nature.
"Delimed skins are subjected to intermediate unit operations such as bating, pickling, before chrome tanning agent treatment and this is followed by chrome fixation in another unit operation called basification.
"Since all these operations are performed in water medium with chemicals, it uses the scarce resource of usable water and generates enormous amount of waste water containing plenty of unabsorbed hazardous chemicals," says Subhendu Chakrabarti, Senior Principal Scientist at CSIR-CLRI.
Affluents from tanneries are major sources of pollution of water bodies in many areas. The new composition for waterless chrome tanning would not only save time, but would also be economical and bring down pollution.
"A new composition for waterless chrome tanning with time saving to the extent of about 30 per cent. Delimed skins are treated with the new chrome composition without addition of any water or any other liquid medium. The process reduces number of unit operations and hence, is more economical.
"It also reduces the requirement of conventional chrome tanning agent by about 50 per cent. Moreover, absence of water in tanning ensures no effluent generation. Thus, it has environment compliance already in place," Chakrabarti says.
CSIR has already applied for the patent for the new technology, he adds.
