Turbidity Removal from a Model Solution by Continuous Mode Electrocoagulation and Evaluation of Energy Consumption

Abstract

The purpose of the research has been the construction of a new electrocoagulation (EC) equipment and its technical evaluation in the treatment of a model solution with a high level of turbidity. The EC system contains six cells installed in series, coupled to a flocculator and a clarifier (sludge decanter), each cell unit is composed of a cylindrical aluminum (Al) anode and a solid stainless-steel rod as cathode in connection with a DC power supply, the aluminum anodes are replaced by iron (Fe) according to the proposed tests. The influence of two factors, such as the applied electric potential and the type of electrode used, on turbidity removal performance, total dissolved solids (TDS) and electrical energy consumption were examined. The tests were carried out using a two-factor factorial design, electrical potential at (0, 3, 6 and 9 V) and type of anode (aluminum and iron). The investigation of the operating parameters was carried out in continuous mode. The initial turbidity of the water to be treated was set at 84.5 NTU, a value generally found in surface water. The results showed that the best conditions for turbidity removal were at an electrical potential of nine volts reaching a removal of 82.29 % and an energy consumption for aluminum electrodes of 0.7142 kWh/m3. It is also observed that the value of total dissolved solids after treatment is still slightly high. In conclusion, electrocoagulation with Al/steel electrodes proved to be an appropriate technology for water treatment due to its turbidity removal efficiency and low electrical energy consumption.