A review of electrocoagulation technology for the treatment of textile wastewater

Abstract

<jats:title>Abstract</jats:title><jats:p>The conventional coagulation technique of textile wastewater treatments is plagued with the issue of low removal rate of pollutants and generation of a large quantity of sludge. Recently, electrocoagulation (EC) technique gained immense attention due to its efficiency. The technique involves dissolution of the sacrificial anodes to provide an active metal hydroxide as a strong coagulant that destabilizes and amasses particles and then removes them by precipitation or adsorption. EC process is influenced by operating parameters such as applied current density, electrodes material and configuration, type of electrical connection, pH and conductivity of the solution, and mixing state. Consequently, this work reviewed the major and minor reactions of EC process with operational parameters, design of EC cell, mass transfer studies and modeling, and industrial wastewater applications. The work also includes comparison of EC technique with conventional coagulation and combinations with other techniques. Special emphasis is on removal of pollutants from textile wastewater. Further, the electrical energy supplies and cost analysis are also discussed. Even though several publications have covered EC process recently, no review work has treated the systematic process design and how to minimize the effect of passivation layer deposited on the surface of the electrodes. EC process with rotating electrodes has been recommended to reduce this phenomenon. The effect of electrodes geometry is considered to enhance the conductivity of the cell and reduce energy consumption. The studies of ionic mass transfer were not implemented before special by limiting current method during the EC process. Moreover, no aforementioned studies used computational fluid dynamics modeling to present the mass transfer inside the EC reactor.</jats:p>

Removal of Congo red aqueous solution using Leucaena leucocephala seed’s extract as natural coagulant

“…Textile industry consumes huge amount of water and chemicals during its operation. Consequently, a high volume of wastewater containing acids, solvents, starch, bleaching agents, dyes, etc., that contribute to high level of biological oxygen demand (BOD), chemical oxygen demand (COD), turbidity, toxic chemicals, and dyes (Naje et al 2016;Verma et al 2012) is usually generated. In developing countries, textile wastewater is most of the time directly discharged to river body without further treatment.…”

Modeling and Simulation in Engineering Modeling of the Electrocoagulation Processes in Nonisothermal Conditions

“…, and ϕ � (y * − y) • δ − 1/2 are corresponding regularizing transformations. Expressions for regular parts of the asymptotic solutions are found as a result of applying the procedure of substitution of the series (9) and (10) and the equation of coefficients for the same powers of the small parameter and solving the corresponding problems:…”

“…e change in concentration S is described by means of the scalar transport equation with the contributions of turbulent [10]:…”

A Review of Promising Electrocoagulation Technology for the Treatment of Wastewater

“…In solution the positively charged ions are attracted with the negatively charged hydroxides to produce ionic hydroxides that have a strong attraction towards dispersed particles as well as counter ions to cause coagulation [12].…”