Experimental analysis of integrated ultrafiltration and reverse osmosis process for water recovery from textile wastewaters: economic, and environmental perspective

Textile industries are significant contributors to wastewater generation due to the nature of their manufacturing processes. Wastewater is produced at various stages of textile production, including pre-treatment, dyeing, printing, finishing, and washing. Traditional effluent treatment plants (ETP) reduce the pollution load of the wastewater before discharging it into the environment. However, ETP-treated water may not qualify for reuse in the production process. Textile industries are known to consume significant amounts of water, including groundwater, in their manufacturing processes. The extraction of groundwater by textile industries can contribute to the depletion of local water sources, which can have severe environmental and social consequences. This study focused on evaluating the effectiveness of ultrafiltration (UF) and reverse osmosis (RO) as advanced treatment processes to recycle textile wastewater in Bangladesh. A mobile UF and RO unit setup was utilized at six selected local factory sites to further treat the effluent discharged from their effluent treatment plants. A specific permeate-to-reject flow rate ratio of 60:40 was maintained in the RO unit during advanced treatment to assess the changes in water quality in the permeate and reject streams and the efficiency of contaminant removal. The results of the study indicated that the recovered water quality met the process water quality standards, which is suitable for use in local textile factories. The corresponding capital and operational costs for water recovery were estimated for the selected textile industries. The analysis revealed that the cost of advanced water treatment amounted to approximately $0.24 per cubic meter of water recovered. Furthermore, the study demonstrated that it was possible to reduce the blue water footprint of the factories by up to 60% based on the operating configuration of the RO unit. Additionally, a substantial reduction in the grey water footprint was observed, varying from 217 to 28024 m3 day-1. This leads to a reduction in the total water footprint of the selected factories in the range of 37.6% to 89.3%.