Investigating the tolerance of nano-filtration for the treatment of wastewater

ABSTRACT The textile industries generate highly concentrated and toxic waste streams which are disposed of without any pretreatment leading to environmental imbalances. Therefore, such waste streams need to be treated before directly discharging. This study explores the nano-filtration (NF) approach for dye effluent remediation. Congo red dye is the widely used chemical that imparts red colour to fabric and is highly toxic when emitted in a very minute amount of 3 mg/L. Therefore, a polyamide-based NF HFT-150 was implemented for the removal of Congo red dye (CD), noting the influences of feed pressure (1–12 kg/cm2) and inlet concentration (10–100 mg/L) used for examining the permeate flux in the process. It was reported that 99.7% removal was obtained at a feed pressure of 6 kg/cm2 with permeate flux of 7.9 mL/min cm2 for an initial concentration of 10 mg/L. Moreover, the samples from a small scale textile industry from Pali, Rajasthan, were collected, and the physicochemical properties were evaluated, revealing the total dissolved salts of 8560 mg/L. The collected sample was treated by NF HFT-150, indicating that potentially strong discolouration was reported at 6 kg/cm2 feed pressure. Therefore, it can be suggested that nano-filtration could be efficiently implemented for textile effluent treatment. Highlights A polyamide-based NF HFT-150 was implemented for the removal of Congo red dye. A strong efficacy of 99.7% was obtained at a feed pressure of 6 kg/cm2. Wastewater samples from a small-scale textile industry from Pali, Jaipur Rajasthan, were collected. NF HFT-150 membrane resulted in strong discolouration of wastewater sample at 6 kg/cm2 feed pressure. GRAPHICAL ABSTRACT