Pre-Treatment of Textile Industry Wastewater Using Ceramic Membranes

Abstract

Textile dyeing processes are among the most environment unfriendly industrial processes, because they produce coloured wastewaters that are heavily polluted with dyes, textile auxiliaries and chemicals. The wastewaters originating from dyeing processes are generally characterized by the high content of color caused by the dyestuffs; salts; chemical oxygen demand (COD) deriving from additives such as acetic acid, detergents and complexing agents; suspended solids including fibers; high temperature and broadly fluctuating pH. Since textile is one of the major industries and it utilizes a huge volume of water, membrane technology can be an efficient and cost-effective method for treating textile effluents. Membrane separation process is a novel separation technology with high separation efficiency, low energy consumption, easy operation, and no pollution. In the present work, ceramic membranes have been evaluated for their suitability in removing COD, colour, conductivity, TDS, turbidity etc. to treat the wastewaters of textile processing. A low-cost ceramic membrane has been prepared in laboratory using paste method. The prepared membrane had a porosity of 40% with an average pore diameter of 274 nm. The water permeability of the membrane was 1376 L/m2.h.bar. The prepared membrane showed excellent corrosion resistance against basic medium. Two types of wastewater, namely, sulphate containing and chloride containing textile dye bath effluents have been collected from a cotton mill located in Ludhiana. The wastewater has been analysed for contaminants before and after the dead-end microfiltration experiments. Complete (100%) removal of TSS was obtained for both types of wastewater. Considerable removal of COD, TDS, BOD and color has been achieved in the microfiltration process. The results showed that the prepared membrane has a very good potential to be used for pretreatment of textile dye bath effluent prior to NF/RO.