Water pinch analysis using multiple contaminants for all wet streams in textile industry

Textile sector consumes huge amount of water in water intensive operations including bleaching, dyeing, and finishing. In this study, water pinch analysis (WPA) was applied on a textile industry using multiple contaminant analysis, to minimize the freshwater consumption and wastewater generation. Water design software was used for comprehensive evaluation of direct reuse and regeneration recycle options, for all wet streams of the industry. Three con-taminants including total dissolved solids (TDS), total hardness (TH) and chemical oxygen demand (COD) were selected for WPA, contrary to single contaminant approach in the past stud-ies. After applying WPA (direct reuse) one by one for each contaminant, freshwater reduction of 56.5% for TDS, 58.6% for TH and 32.8% for COD was achieved. COD is the most sensitive parameter as it gives minimum freshwater reduction, and hence was selected as a key/limiting contaminant. For regeneration recycle option, selecting moving bed biofilm reactor as regener-ation method and COD as limiting contaminant, 69.43% of freshwater reduction was achieved. By application of WPA outcomes, cost reduction of 33% and 50% of the current operating costs could be attained for direct reuse and regeneration recycle options, respectively.