Electrochemical treatment of actual dye house effluents using electrocoagulation process directly powered by photovoltaic energy

In the present work, the decolorization treatment of colored wastewaters produced from polyamide textile dyeing is studied using the electrocoagulation process with sacrificial aluminum electrodes. The electrical energy is obtained from a solar photovoltaic array by directly connecting it to the electrocoagulator without batteries. The photovoltaic electrocoagulation (PV-EC) system is made versatile according to the instantaneous solar irradiation by adjusting the wastewater flow rate to the current intensity supplied by the photovoltaic array. All the PV-EC experiments were performed in Kavala Institute of Technology (latitude 40 degrees 55, longitude 24 degrees 22, and altitude 138m above the sea level). The purpose of this paper is to investigate all parameters affecting the efficiency of the process, such as initial wastewater pH, conductivity, operating time, flow rate, and solar irradiation. The efficiency of the EC process was followed by measurements of turbidity and chemical oxygen demand (COD). According to the obtained experimental results, fast and effective decolorization of the treated wastewater occurred in a few minutes of electroprocessing. Turbidity was quantitatively reduced from 103 to 0.2 NTU, amounting to a removal percentage of over 99%, whereas COD was reduced by 65%. The proposed process is appropriate for decolorizing colored textile dye wastewaters and especially for small applications in remote and isolated locations without connection to public electric grid.