Textile wastewater treatment using electrocoagulation and electro-assisted fenton oxidation | |
| Author | Naqvi, Syed Mobeen Hassan |
| Call Number | AIT Thesis no.EV-26-23 |
| Subject(s) | Textile waste Textile industry--Environmental aspects Electrocoagulation |
| 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 | Textile effluent represents one of the major sources of water pollution, characterized by high colour intensity caused by the presence of recalcitrant organic pollutants, surfactants, salts, and auxiliary chemicals. Among the main issues concerning textile effluents are the high chemical oxygen demand (COD), strong colouration, and poor biodegradability of the contaminants in dyes, which render conventional treatments incapable of providing complete remediation. In this regard, an integrated electrochemical treatment process involving electrocoagulation and electrooxidation-assisted Fenton (EO-Fenton) treatment was evaluated for the optimal removal of colour and COD values, meeting discharge criteria accordingly.A synthetic textile effluent was prepared by the addition of Reactive Black 5 and Reactive Blue 19 dyes, as well as sodium chloride, sodium dodecyl sulfate, acetic acid, and glucose, to obtain a composition close to real-textile wastewater. Such an effluent had a COD of about 1560 mg/L. First of all, electrocoagulation (EC) was performed in an iron-stainless steel electrode system by means of optimizing parameters by Response Surface Methodology (RSM) using Central Composite Design (CCD). The variables involved in the optimization included pH, current density, and reaction time, all of which influenced both colour and COD removal. The optimized EC process conditions determined were an initial pH level of 5.3, current density of 17.51 mA/cm², and a reaction time of 20 min. Such conditions allowed EC treatment to serve as a good pre-treatment by eliminating considerable amounts of the pollutants and making subsequent oxidation easier.Then, the effluent treated via optimal EC conditions was used to perform an EO-Fenton process in the presence of graphite-anode and stainless-steel-cathode electrodes under acidic conditions. EO-Fenton process optimization was performed by employing Box-Behnken Design (BBD) and considering three factors, namely, the dosages of ferrous sulfate and hydrogen peroxide, and reaction time. As a result, 100% colour removal rate was observed in all EO-Fenton treatments conducted during optimization, suggesting total decolourization in all experimental design points. Since colour removal was not dependent on variable values, further modeling was concerned with COD only. Significant quadratic modelling revealed the optimum values of variables, including ferrous sulfate heptahydrate at 3.62 g/L,H2O2 (30%) at 35 mL/L, and a reaction time at 56.14 min. Under such conditions, the model predicted a maximum COD removal of 92.73%, which corresponds to a final COD of about 113.44 mg/L out of an initial 1560 mg/L. Experimental confirmation resulted in a 92.60% COD removal rate, producing an effluent having a COD of 115.49 mg/L. Based on the analysis of the treated effluent, it can be stated that the process was able to provide effluents meeting inland surface water discharge limits in Thailand, Pakistan, Bangladesh, and India. For China and Vietnam, the treatment resulted in an effluent that met sewer discharge criteria. In addition, the economic aspect of the optimized treatment process was evaluated through operating cost estimation, which showed an overall operational cost of 986.37 THB/m³.Overall, it can be stated that the sequential EC-EO-Fenton treatment system proved to be an effective method for treating textile effluents, especially for those with persistent dye compounds and high organic loads. For the future research, it is recommended to focus on improving the economic feasibility of the process, evaluate its performance with the real textile effluent under continuous-flow pilot studies, and also devise sludge management and scale-up potential. |
| Year | 2026 |
| Type | Thesis |
| School | Faculty of Civil and Environmental Engineering (2026) |
| Department | Other Field of Studies (No Department) |
| Academic Program/FoS | Environmental Engineering and Management (EEM) |
| Chairperson(s) | Ghimire, Anish |
| Examination Committee(s) | Ekbordin Winijkul;Cruz, Simon Guerrero |
| Scholarship Donor(s) | Thai Pipe Scholarship;AIT Scholarship |
| Degree | Thesis (M. Sc.) - Asian Institute of Technology, 2026 |
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