Bound in leather
WHEN the international community began to talk about eco-friendly imports about 8 years ago, Indian exporters panicked. Used to circumventing Indian pollution laws with the collusion of corrupt officials, Indian exporters realised that they dare not flout guidelines on pollutants set by importing countries.
The new standards necessitated the substitution of several chemicals used in the leather industry, which formed the bulk of Indian exports. Three years ago, Germany banned the use of pentachlorophenol (PCP), a leather preservative. More restrictions followed: chromium emission to the maximum of 120 mg per pair of shoes and volatile organic substances to less than 150 mg per metre cube.
A significant role in meeting the standards imposed by the importing countries is being played by the Central Leather Research Institute (CLRI).
The current leather manufacturing process uses several chemicals that are harmful to the environment. The process commences with the original soaking or curing process, where salt is used to preserve the raw material. When this salt is transferred into the effluent, it leads to soil salinity. But now steps are being taken to reduce the quantum of salt by first allowing the salt to naturally filter out, and then introducing mechanical desalting using a perforated drum, which removes 30 per cent of the salt. A demonstration centre based on this has already been established by CLRI in Pallavaram-Chromepet (Madras).
The CLRI has also targeted chromium, which is used extensively in the tanning process. Upto 60 per cent of the chrome used passes into the effluent. Western nations have been clamouring for chrome-free tanning. Substitutes such as aldehydes are being tried out.
Another process under pressure is the liming process for the removal of hair and other unwanted proteinous matter. Liming requires the use of toxic sulphides. The CLRI has now developed an enzyme, clarizyme, which requires only a small quantity of toxic sulphides to carry out the liming process.
In place of synthetic dyestuffs like benzedine, considered carcinogenic, natural dyestuffs obtained from the bark of trees like wattle and chestnut are being tried out.
Says P Prabhakaran, executive director of the Council for Leather Exports, "India is responsive, but overnight we can't move to processes that totally avoid substances like chromium."
Common Effluent Treatment Plants (CETPs) for recycling waste water are also to be commissioned at 8 major leather industry clusters in the country. But here too there are inherent problems. Says Mohammed Jaffer Ahamed, secretary of the All India Skin and Hide Tanners and Merchants Association, "A CETP was originally supposed to cost about Rs 1.5-2 crore. But prices have escalated to Rs 4-5 crore because of delays involving purchase and registration of land. We are helpless."