Electrochemical Degradation of Methylene Blue by a Flexible Graphite Electrode: Techno-Economic Evaluation

Abstract

In this study, electrochemical removal of methylene blue (MB) from water using commercially available and low-cost flexible graphite was investigated. The operating conditions such as initial dye concentration, initial solution pH, electrolyte dose, electrical potential, and operating time were investigated. The Box-Behnken experimental design (BBD) was used to optimize the system’s performance with the minimum number of tests possible, as well as to examine the independent variables’ impact on the removal efficiency, energy consumption, operating cost, and effluent MB concentration. The electrical potential and electrolyte dosage both improved the MB removal efficiency, since increased electrical potential facilitated production of oxidizing agents and increase in electrolyte dosage translated into an increase in electrical current transfer. As expected, MB removal efficiency increased with longer operational periods. The combined effects of operating time–electrical potential and electrical potential–electrolyte concentration improved the MB removal efficiency. The maximum removal efficiency (99.9%) and lowest operating cost (0.012 $/m 3 ) were obtained for initial pH 4, initial MB concentration 26.5 mg/L, electrolyte concentration 0.6 g/L, electrical potential 3 V, and operating time 30 min. The reaction kinetics was maximum for pH 5, and as the pH increased the reaction rates decreased. Consequent techno-economic assessment showed that electrochemical removal of MB using low-cost and versatile flexible graphite had a competitive advantage.

Bifunctional Electrocatalysts for Overall and Hybrid Water Splitting

“…Another typical pollutant in wastewater from textile, cosmetic, paper, and leather industries is organic dye, − which is generally carcinogenic and mutagenic to organisms. Integrating electrochemical oxidative decomposition of these organic dyes with preferred kinetics and HER to achieve simultaneous hydrogen evolution and dye degradation would gain both economic and ecological benefits.…”

Mechanism and Techno‐Economic Analysis of the Electrochemical Process

“…Recently, Goren et al [93] made a techno-economic evaluation for the degradation of methylene blue (MB) dye using graphite electrodes. Electric potential (EP) was found the most effective parameter for the operating cost (OC) of the system.…”

“…Consequently, factors such as pH, electric dose, electrolyte concentration, and operating time were taken. The optimized conditions obtained for the highest removal efficiency and the lowest operating cost were calculated to be 99.9 % and 0.012 $ m -3 , respectively, at pH 4, 26.5 mg L -1 MB concentration, 0.6 g L -1 NaCl concentration, and 3 V electric potential for 30 min time [93].…”

Supramolecular Structural-Based Graphene Oxide Lamellar Membrane for Removing Environmental Pollutants from Wastewater

“…Therefore, developing a method or technology for the desalination of seawater and industrial wastewater is of prime importance. Till now, several separation methods, including evaporation, pressure-induced solid particle removal, adsorption, electrochemical operations, and coagulation or flocculation have been developed for the purification and desalination of wastewater. However, these methods have a few drawbacks, such as low efficiency, tediousness, and expense.…”