Eco-Friendly Treatment Strategies for Wastewater Containing Dyes and Heavy Metals

Abstract

In the present scenario, people are suffering due to the scarcity of freshwater and clean drinking water and it remains a worldwide problem. Fast growth of industries and urban localities and change in lifestyle lead to the increase in the necessity of different kinds of synthetic materials and have led to pollution of water. Water pollution is a major environmental issue faced by the modern world, which leads to ecological disequilibrium that can cause harmful effect on flora and fauna of the ecosystem. Heavy metals and synthetic dyes are the major pollutants to be prioritized in wastewater treatment because of their lethal toxicity. Heavy metal poisoning in human being could have a direct impact on the drinking water, on the very air for breathing, and on the food chain. Synthetic dyes which are in use are highly poisonous and difficult to degrade because of their complex form. At present, researchers are focused on the treatment of wastewater containing toxic and complex organic contaminants. Adsorption is a promising technology for treating wastewater with heavy metal contaminants. Recovery and reusability of the adsorbents make adsorption an eco-friendly and cost-effective technology. Photocatalysis is a highly proven treatment technique for dyes intoxicated wastewater. Conversion of non-biodegradable and complex organic dyes into simple biodegradable molecules by photocatalysis is a greater addition in wastewater treatment. Concentration of heavy metal ions could be measured throughout the treatment process using Atomic Absorption Spectrophotometer (AAS), and for dyes, UV–Visible Spectrophotometer could be employed. Kinetic modeling and adsorption isotherms would pave the way for the better understanding of the rate and nature of the adsorption of heavy metals. Biochemical oxygen demand (BOD), chemical oxygen demand (COD), and eco-toxicity studies are used to monitor the treatment processes.