Purolite A120S weak base anion exchange resin is integral to zero liquid discharge systems in the textile dyeing industry. Used for reduction of color, Biological Oxygen Demand (BOD) and Chemical Oxygen Demand (COD) from textile dye wastewater, the resin removes color through the mechanisms of ion exchange, adsorption and filtration. Subsequent regeneration of the resin easily removes the adsorbed color, enabling repeated use of the resin and so reducing waste.
When Purolite® A120S is used in combination with Purolite® C104Plus weak acid cation resin to pretreat the feed water to a reverse (RO) plant, both color and hardness are removed from the water. This protects the RO membranes from fouling and scaling and allows the RO to operate at higher recovery rates.
The almost colorless RO reject brine produced allows recovery of the salts in the brine as Glaubers salt after additional steps of evaporation and crystallization. The high clarity of both the brine solution and the crystallized salt means these can be sustainably recycled back into the textile dyeing process, eliminating the need to dispose of solid waste.