ja_mageia

Cleaner Technology means an Eco-Friendly system process where the discharge of the tannery will be as less harmful as possible and the product coming out of the process will have no environmental threat. At the same time the product will be high in quality and the total cost of production will be reduced because of the change in effluent discharge.

The key targets that were identified in Hazaribagh Tanneries are:

• Replacement of chromium
• More effective use of chromium
• More efficient use of chemicals
• Sulphide free unhairing, possibly with hair recovery
• Utilization of wastes
• Re-use of water
• Odor control
• Solvent free finishing
• N-free Deliming
• Hide chilling to avoid salt in the effluent
• Hair recovery processes to reduce BOD/COD of the effluent
• Enzyme-assisted unhairing to reduce sulphide
• C02 deliming to reduce ammonia in effluent
• Better uptake/exhaustion of chrome or chrome recovery/recycling to reduce chrome in the effluent
• Alternative mineral tanning agents to avoid chrome in effluent or solid wastes
• Water-based and solvent-free top coats to avoid VOC

Some achievements:

1. successful demonstration of the hair saving process and scope for reduction of COD/BOD load in effluents from beam house
2. improved conventional tanning reduction of Cr in spent liquor from 5600 mg/l to 1100 mg/l
3. recommendations towards proper water management and reduction of water consumption

Water meter installation by UNIDO National Expert:

Water consumption of a tannery is an influencing factor in environment pollution, CETP, cost of discharging effluent of a tannery and above all quality of the processed leather. Low water consumption is highly recommended for SCP. Normally in developed countries only 15-20 cubic meter water is used for tanning and re-tanning of one ton leather. Whereas we are using 35-40 cubic meters per ton. By installing water meter on pilot basis in selected tanneries during February 2010, the project already achieved some success in water management where 20-25% less water is needed.

Plan for development in drum technology:

We found that water consumption is high in the drums currently used in Hazaribag tanneries. The project proposes new technology and modification of drums so that waeffter consumption will come down from 30 to 15 cubic meter and the project intends to set up some upgraded drums on a pilot basis to introduce the technology.

Solar energy:

Solar energy can be effectively used in the tanneries to reduce energy consumption. To demonstrate this effectiveness the Re-Tie Bangladesh Project has installed a solar energy system at M/S Lien Tannery, Hazaribag.

Chemical preparation tank:

As a part of SCP, for maximum input of chemicals into leather, the project has installed a chemical preparation tank at M/S Lien Tannery, so that waste water COD and BOD can be better regulated.

Hair saving machine:

Conventional liming method produces high COD, BOD, and SULPHIDE and NITROGEN content. By installing advanced liming technology for hair saving at Bay Tannery in Hazaribag, the project has achieved success in lowering COD, BOD, organic and sulphide content.

Equipment Distribution:

The project has distributed several equipments to different tanneries which will assist in achieving cleaner production.  Among these equipments are high efficient pH meter, Boehme meter, thermometer, moisture meter etc. These digital instruments are helping to control the process in tanneries and as a result less chemicals are now used and quality of the leather has also improved compared to the period before using these meters.

Waste Management:

Recently chrome was detected in the poultry and fish feed available in market, which comes from the solid waste from tanneries which is used to produce these feeds. Some of our National Experts investigated the matter and informed the media in a TV program on waste management by the channel ATN Bangla. An international expert engaged by the project, Mr. Patrick Zerhusen, took some feed samples produced from the tannery bi products and confirmed through tests that chrome was indeed present. Amid the media awareness the High Court has recently banned all production of fish and poultry feed made from tannery wastes until safe and chrome free production technology are found and implemented. It may be noted that chrome is carcinogenic and mixed in the food chain can cause cancer in humans, among other diseases. The Re-Tie Bangladesh Project is also working, through the efforts of UNIDO technical experts, to find sustainable technology that will address the matter.

Chrome reduction in spent liquor:

The UNIDO International Expert Mr. Patrick Zerhusen did some trial to reduce chrome in s;pent liquor. In our country around 7- 8% chrome is used to produce a wet blue, much of which goes to the spent liquor instead of being absorbed by the pelt. As a result excess chrome of the spent liquor (5600 mg/l) is harming the environment. The project has successfully made a trial in Apex tannery using only 5.5% chrome.