Photo-alternating current-electrocoagulation technique: Studies on operating parameters for treatment of industrial wastewater

Abstract

In this investigation, several electrochemical and advanced oxidation processes (AOPs), including photolysis (UV), direct/alternating current-electrocoagulation (DC/AC/EleC), and photo-direct/alternating current-electrocoagulation (UV/DC/AC/EleC) process were examined regarding their capacity in order to reduce the amount of chemical oxygen demand (COD) and color in distillery industrial wastewater (DIW), as well as the effect these factors have on the amount of electricity required to treat the wastewater. Experimental results showed that compared to single UV, DC/EleC, AC/EleC, and hybrid UV/DC/EleC processes, the hybrid UV/AC/EleC process provided excellent color-100 % and COD-100 % removal efficiencies with a lowered usage of energy of 8.54 kWhr m−3. The influence of critical operational variables such as treatment time (30–240 min), photo (8–40 W), pulse duty cycle (0.14–0.86), current (0.15–0.90 Amp), pH (1.50–11.50), chemical oxygen demand (3000–9000 mgL−1), inter electrode spacing (1–4 cm), electrode combination (Fe/Fe, Fe/Al,Al/Fe, Al/Al), and electrolyte concentration (1–5 g L−1) on the efficiency of% color and COD removal, as well as the energy utilization of DIW were examined applying a hybrid UV/AC/EleC method. The synergistic index between UV and the AC/EleC process was also examined and discussed in this work. The UV/AC/EleC technique is the most advantageous choice in comparison to the other approaches since it can be applied to properly and efficiently remove pollutants from wastewater and industrial effluent.