Magnetic adsorbents for the treatment of water/wastewater—A review

In recent years, adsorption has displayed promising and effective results as a treatment technology for water and wastewater by industries. In the process, a number of adsorbents have been synthesized and applied for the treatment of pollutants such as metals, dyes, pharmaceutical products in solutions. However, for adsorption to be unconditionally adopted by industries, a few obstacles such as high capital cost, difficult segregation of adsorbent from solution, and complex synthesis processes need to be addressed. The removal of suspend adsorbents in wastewater from a continuous flow system is a challenge which if addressed properly would enable us to recover the spent adsorbent efficiently. The spent adsorbents can then be regenerated and used again by the industries thereby leading to reduced capital investment. Therefore, studies have been carried out aiming at the incorporation of magnetism in such adsorbents to aid their removal from wastewater. This review aims to comprehensively list and discuss adsorbents which exhibit magnetic properties and their adsorption behaviour under diverse conditions. The literature survey presented in this paper renders evidence to the good potential of magnetic adsorbents to remove various pollutants from wastewater. However, the practical utility of such adsorbents needs to be explored before they can be commercially applied.