Water conservation through implementation of ultrafiltration and reverse osmosis system with recourse to recycling of effluent in textile industry–A case study

In compliance with the protection of the drinking water source in one of the state capital of India, a cluster of small scale textile industries implemented membrane processes based on treatability studies for recovery of boiler feed water quality with recourse to effluent recycling/reuse. The paper addresses to a case study in one of the textile units on upgradation of a full scale effluent treatment plant comprising chemical, biological, tertiary and advanced treatment processes. Based on the adequacy assessment of chemical and biological processes, improvement in the performance of the unit processes were achieved through optimization of coagulant dosage for chemical coagulation and build-up of active biomass in the activated sludge system. In addition, application of membrane separation processes comprising ultrafiltration and reverse osmosis units are also highlighted including disposal of reverse osmosis (RO) rejects through evaporator leading to zero liquid effluent discharge. The treatment scheme implemented resulted in conservation of around 55% of fresh water demand for industry.