Direct filtration of Procion dye bath wastewaters by nanofiltration membranes: flux and removal characteristics

Abstract

The treatment and reuse of industrial wastewaters by membrane processes has become more attractive in the last few years due to constraints on water usage. The aim of this study was to investigate the direct filtration of reactive dye house wastewaters by nanofiltration membranes based on permeate flux, and sodium chloride and colour removal. Experiments were performed using both synthetic and industrial dye bath wastewaters with the fluxes of the industrial dye bath wastewaters lower than those of the synthetic solutions. The effects of operating conditions such as pressure and pH were assessed. Studies with DS5 DK type (polysulfone-polyamide) membranes showed that nanofiltration membranes are suitable for direct treatment of wastewaters and the permeate quality was appropriate for reuse in the dyeing process. Pre-treatment and neutralisation were important for recovery of large amounts of salt and water from the permeate stream. Neutralisation of the solution with HCl rather than H 2 SO 4 gave a better permeate from the point of view of the reuse. The highest permeate flux and colour removal and the lowest salt removal were achieved with the HCl neutralisation.  2003 Society of Chemical IndustryKeywords: nanofiltration; neutralisation; reactive dye; membrane fouling; NaCl recovery INTRODUCTIONAs groundwater levels decrease and industrial water prices increase, there is an emphasis on identifying and investing in new water sources for future demands. Such alternative processes include desalination of brackish and sea water, and the reclamation and reuse of wastewaters. Several new unit processes for water and wastewater treatment such as membrane technology have been used in desalination and reclamation of both municipal and industrial wastewaters.

Fabrication and characterization of hydroxylated and carboxylated multiwalled carbon nanotube/polyethersulfone (PES) nanocomposite hollow fiber membranes

“…Membranes have been widely used for the treatment of drinking water [1] as well as for the treatment of various industrial [2,3] and municipal wastewaters [4]. Hollow fibers have been found to be a particularly efficient geometry for many membrane applications [5][6][7][8] due to the high surface to volume ratios (packing density) and favorable mass transfer properties.…”

Removal of Dye from Textile Wastewater Using Plant Oils Under Different pH and Temperature Conditions

“…These include: adsorption [10] , nanofiltration [11,12] , colloidal gas aphrons [13] , ultrasonic decomposition [14] , electro coagulation [15] , coagulation and precipitation [16] , advanced chemical oxidation [17] , electrochemical oxidation [18][19] , photooxidation [18] , predispersed solvent extraction [20] , ozonation [21][22][23][24] , supported liquid membrane [2,25,26] , liquid-liquid extraction [25,27] and aerobic and anaerobic biological processes [28,29] . The advantages and disadvantages of some methods of dye removal from wastewater are given in Table 1.…”

Influence of Temperature and pH on the Stability and Colorimetric Measurement of Textile Dyes

“…More advanced treatment processes include: electro coagulation [26] , ultrasonic decomposition [27] , advanced chemical oxidation [28] , electrochemical oxidation [29,30] , photooxidation [29] , nanofiltration, [31,32] , colloidal gas aphrons [33] , pre-dispersed solvent extraction [34] , ozonation [35][36][37][38] , supported liquid membrane [9,13,39] and liquid-liquid extraction [9,40] . Traditionally, the colourimetric measurement technique has been used to evaluate the effectiveness of these various dye removal methods.…”