Investigating the potential of concentrating dyes from textile wastewater using membrane distillation process | |
| Author | Do Thi Diu |
| Call Number | AIT Thesis no.EV-16-04 |
| Subject(s) | Sewage--Purification--Oxidation Photocatalysis Water Pollution Textile waste Textile industry--Environmental aspects. |
| Note | A thesis submitted in partial fulfillment of the requirements for the degree of Master of Science in Environmental Engineering and Management |
| Publisher | Asian Institute of Technology |
| Abstract | In the textile industry, methylene blue (MB) and reactive black 5 (RB5) are two harmful synthetic dyes commonly applied in dyeing baht for colour generation. Effluent from exhausted dyeing process still remaining high concentration of dyestuffs must to be treated before discharging to the receiving water body. The novel membrane distillation (MD) process promises great potential for condensing textile dye from wastewater. It is supported by this study in which sweeping gas membrane distillation (SGMD) membrane (at bench scale, 0.255 m² membrane surface area) showed excellent dye concentrating factor, less permeate flux reduction and high dye rejection efficiency in both MB and RB5 even under prolonged operating time. After 256 h, the final MB concentration (241.61 mg/L) enhanced 9.3 times compared to its initial concentration with completely dye separation. Though, during prolonged exposure time of MB dye on membrane surface, a fouling layer formed via dye accumulation and caused permeate flux reduction (1.99 –1.0 kg/m².h). However, it can be effectively removed by a weak acid mixture of 0.1% wt. oxalic acid and 0.8% wt. citric acid. In the case of RB5, the permeate flux was relatively stable around 1.9 kg/m².h with concentrating factor achieved more than 11 times (750.59 mg/L -8454.78 mg/L) after 128h running. The SGMD membrane was able to reject above 98.3% RB5 dye from feeding solution. The reactive dye-polymeric membrane interaction and long-term use were supposed as the reasons resulting in membrane wetting. By applying ethanol and hot drying on the wetted membrane can be performed at 99.5% membrane regeneration. The cost analysis calculated based on a 1 m³/day pilot SGMD plant reveals the unit cost of treatment to be 264 $/m³. 56% of this cost is associated with heating of the feed solution, revealing this technology is more suitable when for hot wastewater stream from the textile industry, and when there is a strong potential for reusing the concentrated dyes in the dyeing process. |
| Year | 2016 |
| Type | Thesis |
| School | School of Environment, Resources, and Development (SERD) |
| Department | Department of Energy and Climate Change (Former title: Department of Energy, Environment, and Climate Change (DEECC)) |
| Academic Program/FoS | Environmental Engineering and Management (EV) |
| Chairperson(s) | Visvanathan, C.; |
| Examination Committee(s) | Annachhatre, Ajit P.;Loc, Thai Nguyen; |
| Scholarship Donor(s) | Deutscher Akademischer Austausch Dienst (DAAD);Asian Institute of Technology Fellowship; |
| Degree | Thesis (M.Sc.) - Asian Institute of Technology, 2016 |