Electro-chlorination using Titanium Alloy Electrodes with and without Coating and Formation of Trihalomethane during Water Disinfection

Abstract

The research investigates the in-situ chlorine generation potential and durability of graphite, titanium, newly identified Ti6Al4V, and coated Ti6Al4V electrodes under varying electric voltage, electrolysis time, inter-electrode distance, and electrolyte concentration, through experimental investigations using a solar-powered electro-chlorination (EC) lab-scale set-up. The experimental observations revealed that the maximum concentration of Chlorine Stock Solution (CSS) was achieved for the coated Ti6Al4V electrode (35.45 mg/L) under optimized conditions: 10 V electric potential, 60 min electrolysis time, 4 cm inter-electrode distance, and 4 g/L electrolyte concentration, for the developed laboratory set-up. The coated Ti6Al4V electrode outperforms both graphite and the Ti6Al4V electrode without coating in terms of electrode durability, indicating the effectiveness of the coated Ti6Al4V electrode in terms of maximum chlorine generation and durability. The CSS was used for water disinfection, and the quantum of trihalomethanes (THMs) generated was measured using gas chromatography–mass spectroscopy (GC-MS). It was observed that the THMs formed after disinfection using the EC-generated CSS are below the permissible limit for drinking water. The research concludes that the solar-powered EC set-up provides a safe, sustainable, and energy-efficient solution for water disinfection. The novel coated Ti6Al4V electrode exhibits effectiveness and durability during EC, with minimum THMs formation.