Decontamination of Wastewater Containing Organic Pollutants: A Review

Abstract

Every day, tons of inadequately treated wastewater and industrial effluents are dumped into water bodies, resulting in contamination, changing their physical, chemical and biological characteristics and putting human and ecosystem health at risk. Several pollutants are detected in water bodies such as: dyes, drugs, trace metals, surfactants, polycyclic aromatic hydrocarbons, among others. In this context, it is important to investigate treatment methods that aim to mitigate the effects of pollution. This paper aims to present a review of treatment methods used to remove three classes of organic pollutants: dyes, pharmaceuticals and surfactants. When conducting research on these contaminants, it was observed that methods for removing dyes are the most studied, followed by pharmaceuticals and, finally, surfactants, for which a smaller number of publications is found. Among the methods used to remove these contaminants, the following will be presented in this work: adsorption, electrocoagulation, photoelectrocatalysis, electro-Fenton, anodic oxidation, ozonization and coagulation. Adsorption, coagulation and electrocoagulation are methods that promote the removal of contaminants, that is, these methods lead to separation of contaminants from the medium, instead of leading to their mineralization (total degradation). On the other hand, photoelectrocatalysis, electro-Fenton, anodic oxidation and ozonization have the characteristic of promoting partial or total degradation of pollutants.