Electrochemical Treatment of Heavy Metal-containing Wastewater with the Removal of COD and Heavy Metal Ions

Abstract

The use of electricity to treat water was employed for the first time in the UK a century ago, and since then has been considered a highly reliable method for wastewater treatment. In recent years, the demand for hydrogen gas as a valuable, clean energy source has increased considerably; from this point of view, the electrolysis of wastewater can meet the demand for energy during the process of treating wastewater. In this work, wastewater containing heavy metal ions has been treated by an electrochemical method which not only decreased the chemical oxygen demand value and lowered the number of heavy metals ions but also generated hydrogen throughout the process. A series of experiments were performed under optimum conditions of selected electrode materials, pH values, supply power, and working time. The results obtained indicate that by controlling the key factors of the process, a practical method can be achieved for wastewater treatment which also produces a noticeable amount of green energy. Differential pulse voltammetry measurements were used to determine the properties of an industrial wastewater source before and after treatment, while scanning electron microscopy and energy dispersive X‐ray spectroscopy were applied to investigate the proficiency of the electrode material.

Nanomaterials for the Removal of Heavy Metals from Wastewater

“…Therefore, the removal of heavy metals from water is of great importance and has drawn tremendous attention. Up till now, numerous technologies have been developed to solve this problem, including chemical precipitation [7], ion exchange [8], adsorption [9], membrane filtration [10], electrochemical treatment [11], and so on. Besides, it is often the case that different techniques are combined for a better removal result [12,13].…”

Electrospark Method in Galvanic Wastewater Treatment for Heavy Metal Removal

“…In electrocoagulation methods of galvanic wastewater treatment, adsorption-active hydroxides of iron or aluminum are formed by electro erosion by the electrolytic dissolution of steel or aluminum anodes, respectively. In this case, phenomena such as water electrolysis, particles' polarization, electrophoresis, redox processes, and the interaction of electrolysis products with each other can occur in the electrolyzer [17][18][19][20]. Galvanic coagulation consists of passing wastewater through a galvanic coagulator that contains an active anode and cathode mixture, for example, iron and aluminum chips, iron chips, coke [13], etc.…”

Highly Efficient Adsorption of Cd(II) onto Carboxylated Camelthorn Biomass: Applicability of Three-Parameter Isotherm Models, Kinetics, and Mechanism

“…It has a strong ability to become enriched, and easily enters the body through the food chain, resulting in a hazard to human health through water, air, and plants [5]. A number of methods have been proposed for remediation of heavy metal ions from industrial effluents such as neutralisation, ion exchange, solvent extraction, photochemical degradation, electrochemical degradation, membrane separation, reverse osmosis, precipitation and adsorption [5][6][7][8][9][10][11], while these have been proven to be efficient, they are also expensive; by contrast adsorption provides an efficacious method for the remediation of heavy metal ions from water [12].…”