Sector
Textile Dyeing
Volume
75 Cu.m / day
Location
Dhaka, Bangladesh
The Challenge
Water is a business-critical issue for the apparel industries across the value chain. Focus is not only on reducing water consumption; the road to a resilient recovery lies in the economical practices of reuse of recovered RO & Salt water in textile process sequences.
Our client based in Bangladesh is involved in the business of apparel manufacturing and dyeing. Their dyeing unit generates a strong coloured effluent of 12000-13000 Pt-Co units with COD levels of 3000 mg/L. This requires an extensive colour removal treatment and COD reduction in order to achieve a significant recovery.
Novel Solution
Enviros India proposed an integrated innovative water treatment solution to reduce the textile industry water footprint, overall operating costs, and decrease the ecological impact from its wastewater discharge. The company offered a specialized solution for the dyebath effluent treatment as a means to recycle the brine saltwater in textile dyeing process. Further, the recovered RO water will be used in textile washing operations to reduce freshwater consumption costs, and maintain compliance with environmental discharge regulations.
Enviros India designed, installed, and commissioned the 75 m3/day Salt Recovery Plant on a turnkey basis, under the following scheme.
Cost Benefit of Recovered Salt
The 75 KL of effluent @ 25 GPL is subjected to RO for trans-membrane separation and concentration of salts into the brine side of RO. The salt water at brine end of RO is derived as 28 KL (38%) @ 65 GPL, recovering a wholesome 1.8 Ton of salt.
Market value of Glauber salt (at the time of writing) at Bangladesh is BDT 38,000 per Ton.
Cost savings through salt recovery
1.8 T x BDT 38,000 = BDT 70,000 (approx.) per day!
The Result
The effluent was successfully treated reducing the COD pollution and strong colours. 65 GPL of brine solution concentration was successfully achieved. The client now recovers more than 47,000 Liters of water for reuse in their process and 1.8 Tons of salt for reuse in dyeing. The treated reject water meets the environmental norms and is safe for discharge. This has resulted in steep economical savings on investment for the client.
