Treatment of embroidery wastewater containing poly(vinyl alcohol) by electrooxidation process

Embroidery industry wastewater contains high levels of polyvinyl alcohol (PVA), making it resistant to biodegradation and conventional treatment methods such as coagulation and adsorption. Chemical oxidation processes have been successfully used to treat PVA-containing effluents, but the high chemical demand raises significant environmental and sustainability concerns. Recent studies are focused on finding innovative and efficient chemical approaches to effectively treat PVA-containing effluents. This work used an electrooxidation process (EO) with boron-doped diamond electrodes to treat wastewater containing PVA for the first time in the literature. The effects of pH (2.0-8.0), temperature (25-45 degrees C), current (3.0-6.0 A), electrolyte concentration (NaCl of 3.0-8.0 g/L), and oxidation time (0-6000 min) on the removal of total organic Carbon (TOC) were investigated. The pollutant removal mechanism of the process was elucidated using high-performance size exclusion chromatography, Fourier-transform infrared, Ultraviolet-visible, and Fluorescence Spectroscopy methods. The results showed that TOC concentrations significantly dropped from 6584 to 159.10 mg/L after 10 h of treatment at 6.0 A, pH 5.01, and 25, with an estimated 97.6% removal efficiency. Characterization studies showed that much of the wastewater's PVA is broken down, and the halogens are bound to the degraded part of the polymer. The raw wastewater used contained a wide range of pollutants (103-1010 Da). The results showed that the pollutants in the wastewater were successfully removed by EO irrespective of the molecular size. These results demonstrate the superiority of EO over treatment techniques that exhibit selectivity for pollutants with different molecular weights.