Reuse of Textile Dyeing Effluents Treated with Coupled Nanofiltration and Electrochemical Processes

Abstract

The reactive dye Cibacron Yellow S-3R was selected to evaluate the feasibility of combining nanofiltration membranes with electrochemical processes to treat textile wastewater. Synthetic dyeing effluents were treated by means of two nanofiltration membranes, Hydracore10 and Hydracore50. Up to 98% of dye removal was achieved. The influence of salt concentration and pH on membrane treatment was studied. The best dye removal yield was achieved at pH 3 in the presence of 60 g/L of NaCl. After the membrane filtration, the concentrate containing high dye concentration was treated by means of an electrochemical process at three different current densities: 33, 83, and 166 mA/cm2. Results showed a lineal relationship between treatment time and applied current density. Both permeates and electrochemically-decoloured effluents were reused in new dyeing processes (100% of permeate and 70% of decoloured concentrates). Dyed fabrics were evaluated with respect to original dyeing. Colour differences were found to be into the acceptance range.

Treatment of Textile Wastewater by CAS, MBR, and MBBR: A Comparative Study from Technical, Economic, and Environmental Perspectives

“…The dyeing tests using treated water were performed with a laboratory Ti-Color dyeing machine (Prato, Italy) ( Figure 2a) under the following conditions [27]: 10 g cotton fabric, dye concentration of 3% o.w.f (overweight of fiber), liquor ratio 1:10 (1 g fiber/0.01 L dye bath). Three commercial reactive dyes supplied by Dystar were used in the water reuse study: Yellow Procion HEXL, Crimson Procion HEXL, and Navy Procion HEXL.…”

Electrochemical Treatment of Textile Dye Bath Wastewater Using Activated Carbon Cloth Electrodes

“…Several treatment technologies have been used for the treatment of textile wastewater so far. Among these methods, membrane filtration (5), photocatalytic process (6), adsorption (7), coagulation (8), advanced oxidation (9), biological processes (10), and coupled processes (11)(12)(13) are the most commonly used treatment processes. Although they have a satisfactory dye removal efficiency, some disadvantages such as an expensive investment and operating cost, formation of sludge and toxic intermediates, and membrane fouling limit the use of these technologies (4).…”

A Fenton-Like Nanocatalyst Based on Easily Separated Magnetic Nanorings for Oxidation and Degradation of Dye Pollutant

“…Therefore, there is an urgent and serious demand for efficient treatment of these discharged dyes. A great many physical and chemical methods have been exploited to remove/degrade those dyes from wastewater, such as physical adsorption, precipitation coagulation, flocculation, reverse osmosis, filtration, membrane separation, biological process, chemical oxidation, and catalytic degradation [4][5][6][7][8][9]. Nevertheless, some chemical and physical methods such as adsorption and coagulation only transfer pollutants and require more processing.…”