Performance evaluation of a novel electrolytic reactor with rotating and non rotating bipolar disc electrodes for synthetic textile wastewater treatment

Abstract

Textile industry is one of the leading polluters of surface water due to the presence of various types of dyes and other hazardous pollutants. In this study, a novel rotating bipolar disc electrolytic (RBDE) reactor was designed for the treatment of textile wastewater and the performance was evaluated. The turbulence created in the system and enhanced mass transport (coagulants/ions) improved the overall performance of electrolytic cell during rotation. The effect of various parameters like current density, electrical conductivity, pH, rotation speed, and pollutant concentration on the performance of the RBDE reactor was examined in terms of COD, colour and TSS removal. Complete decolorization was obtained in 2 min and 6 min of electrolysis time in rotating and non-rotating mode of operation. COD removal was 4.8 times more in rotating electrode system (230.4 mg/L to 14.05 mg/L, 93.9% removal) compared to static mode of electrodes (230.4 mg/L to 67.9 mg/L, 70.6% removal), in 10 min of electrolysis time. Profilometry analysis confirmed that the rotation increased the electrode dissolution (8.1 μm in static and 62.3 μm in rotating electrodes) and also decreased the thickness of oxide film formation on cathode surface compared to static electrodes (0.55 μm on rotating and 6.48 μm on static electrodes). Moreover, RBDE reduced the energy consumption (1.4 kW h/kg dye) compared to static (2.1 kW h/kg) electrodes system for the complete decolourization of Rhodamine B (RB) dye.