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

Abstract

Due to its high poly(vinyl) alcohol (PVA) concentration, Embroidery industry wastewater is very resistant to biodegradation and classical methods such as coagulation, and adsorption. On the other hand, high chemical consumption is required in chemical oxidation processes. In this study, wastewater containing PVA was treated by an electrooxidation process with Boron Doped Diamond (BDD) electrodes for the rst time in literature. The effects of pH (2.0-8.0), temperature (25-45 C), current (3.0-6.0 A), electrolyte concentration (NaCl of 3.0-8.0 g/L), and oxidation time (0-600 min) were determined. The total organic carbon (TOC) concentration in the wastewater was decreased from 6584 mg/L to 159.10 mg/L (97.6%) at pH 5.01, 6.0 A, 3.0 g/L of electrolyte concentration, 25°C, and 10 hours. In addition, the removal mechanism of the process was elucidated by using HPSEC, FT-IR, UV-VIS, and Fluorescence Spectroscopy methods. Characterization studies showed that the high amount of PVA in the embroidery process wastewater is degraded and the halogens have attached to the part of the polymer where the structure has deteriorated through oxidation. Raw wastewater contains a wide range of pollutants (10 3 -10 10 Da). The results showed that the EO process is not a pollutant-selective technique in terms of molecular weight and it shows its superiority over other processes.