Removal of reactive red 195 from dyeing wastewater using electro-Fenton process in a cell with oxygen sparged fixed bed electrodes

This research focuses on the use of electro-Fenton processes for degradation of reactive red 195, the degradation is achieved by reactions with hydroxyl radicals ( OH) which are produced from Fenton reaction using a new O2 sparged electrochemical reactor consisting of fixed bed cathode made of carbon cylinders and a horizontal array of closely packed steel screens anode. Variables studied were current density, initial dye concentration, oxygen superficial velocity, and number of graphite layers (bed thickness). Color removal efficiency reached 100 % and chemical oxygen demand (COD) removal reached 96 % for the dye initial concentration of 50 ppm at current density =2 mA/cm2, superficial oxygen velocity =0.012 cm/s, 60 miutes contact time, a cell with a three layer of graphite cylinders fixed bed cathode was used. Under these conditions, the energy consumption was found to be 17 kW.h/kg of removed dye, and the electrical cost of dye removal approximate to 0.85 $/ kg dye removed. Kinetics study revealed that dye removal takes place through a first-order reaction. The merits of the present reactor compared to the reactors used in previous studies were highlighted.

Automated summary

This research focuses on the degradation of reactive red 195 using electro-Fenton processes. The study achieved high color removal efficiency and COD removal, highlighting the advantages of the new electrochemical reactor compared to previous studies.