Major Threat in Textile Wastewaters: Tackling Microplastic Pollution with Electrocoagulation Optimized Using Box-Behnken

The textile industry wastewater threatens receiving environments due to its high levels of microplastics (MPs) generated from production processes. This study, to our knowledge, is the first to investigate the optimization of MPs removal from textile industry wastewater using electrocoagulation (EC) by a Box-Behnken Design (BBD). MPs of fiber type, specifically PP type, have been detected in this wastewater at an average number of 105 ± 5 MPs/L. In the EC process using aluminum electrodes, BBD was employed to determine the effects of independent process variables (pH, current density, and time) on microplastic (MP) removal and for process optimization. According to the ANOVA results, the quadratic model created for MP removal and all independent variables were statistically significant (p < 0.05). The optimization results indicated that the optimal conditions for MP removal were pH 7.38, current density 54.16 A/m2, and time 14.96 min, resulting in an optimum MP removal efficiency of 98.10%. Validation experiments conducted under these optimal conditions achieved MP removal efficiency of 98 ± 0.23%, confirming the model’s accuracy. Additionally, the operating cost of the EC process under optimum conditions was calculated to be $0.312/m3. According to the Pareto analysis results, pH was found to be the most effective independent variable in MP removal. This study demonstrates that the MP pollution from the textile industry can be effectively removed with high efficiency and low cost using the EC process.