Electrochemical Techniques in Textile Processes and Wastewater Treatment

Abstract

The textile industry uses the electrochemical techniques both in textile processes (such as manufacturing fibers, dyeing processes, and decolorizing fabrics) and in wastewaters treatments (color removal). Electrochemical reduction reactions are mostly used in sulfur and vat dyeing, but in some cases, they are applied to effluents discoloration. However, the main applications of electrochemical treatments in the textile sector are based on oxidation reactions. Most of electrochemical oxidation processes involve indirect reactions which imply the generation of hypochlorite or hydroxyl radical in situ. These electrogenerated species are able to bleach indigo-dyed denim fabrics and to degrade dyes in wastewater in order to achieve the effluent color removal. The aim of this paper is to review the electrochemical techniques applied to textile industry. In particular, they are an efficient method to remove color of textile effluents. The reuse of the discolored effluent is possible, which implies an important saving of salt and water (i.e., by means of the “UVEC Cell”).

Treatment of batik waste using distillation method

“…Some researchers do research, processing textile waste is adsorption of methylene blue by using activated carbon [3], electrochemical oxidation [4][5][6][7][8][9][10]. But some batik waste processing process above many weaknesses that require expensive chemicals, require the process of separation of chemicals with waste water and generate new waste derived from the remaining chemicals that have been used.…”

Reuse of textile wastewater after homogenization–decantation treatment coupled to PVDF ultrafiltration membranes

“…In general, conventional biological treatment provides good chemical oxygen demand (COD) removal, but low efficiencies in discoloration due to the chemical stability and resistance to microbiological attack of the dyes [4,5]. Chemical coagulation can remove the colour completely, but it generates a sludge which requires an additional treatment to be destroyed [6,7]. These methods are able to meet legislative requirements but they do not allow water reuse in textile processes [8].…”

Sustainable dyeing of denim using indigo dye recovered with polyvinylidene difluoride ultrafiltration membranes

“…In general, conventional biological treatment provides good COD removal, but low efficiencies in discoloration due to the chemical stability and resistance to microbiological attack of the dyes (Bes-Piá et al, 2005;Robinson et al, 2001). Chemical coagulation is a very common treatment but this method generates a sludge which requires an additional treatment to be destroyed (Sala and Gutiérrez-Bouzán, 2012). These methods are able to meet legislative requirements but they do not enable water reuse in textile processes (Barredo-Damas et al, 2010).Recently, there are an increasing number of studies based on industrial waste reuse (Huber et al, 2014;Sathishkumar et al, 2012) and on water reuse (Othman et al, 2014).…”