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Project

Textile Wastewater Treatment System Integrated with Constructed Wetland

Textile industries produce colored wastewater effluent from dyeing and finishing processes. In the dyeing process, some of the dyes are not fixed to the fabrics. Most of these dyes resist degradation by conventional wastewater treatment processes. Dyes also persist in the environment because they are made to have high stability against light, detergents, chemicals, and perspiration. Coagulation, flocculation, and common sedimentation are used to remove dyes from wastewaters. However, the methods are less effective for color removal, and produce large amount of sludge which its disposal remains to be a big challenge. Other methods are membrane filtration, nanofiltration, advanced oxidation process and reverse osmosis are also used to remove dyes and organic matter. But the methods are expensive to acquire as well as high running costs. Examining these methods in detail, they are not feasible for treating textile wastewater. This is due to intensive technology, power demand, and high investment and maintenance costs. Different treatment alternatives have been studied to remove dyes from textile wastewaters, biological methods remain to be considered as most economical and environmentally safe. From the industrial survey, it has been observed that, most of the textile dyes used are azo dyes. In general, complete degradation of azo dye requires both anaerobic and aerobic biological processes. Anaerobic process breaks azo bonds and hence remove color. The aromatic amines from azo bond breaking process can be mineralized under aerobic conditions. Studies have been conducted mostly on synthetic textile wastewater for color removal, with no information on the products of decoloration. These studies have been conducted in regions with large temperature variation at different seasons of the year, especially in the northern hemisphere. The PhD study is aimed at developing a system integrated with constructed wetland to treat textile wastewater. The study is going to use combined sequential biological treatments, anaerobic followed by aerobic together with some physicochemical pre-treatments. The constructed wetland will be used as a tertiary process of textile wastewater treatment. A constructed wetland may provide both anaerobic and aerobic environments for textile wastewater treatment. The study shall establish conditions and combination of technologies that will give optimum and economical ways of decoloration as well as pollutants removal from textile wastewater in tropical areas where the temperature variation between seasons is low.

Date:18 Sep 2019 →  26 Jun 2023
Keywords:Dyes, Decoloration, Biological treatment of wastewater
Disciplines:(Waste)water treatment processes, Solid state and soft matter chemistry, Textile technology, Biocatalysis
Project type:PhD project