Technologies for Removal of Emerging Contaminants from Wastewater
Tahira Mahmood, Saima Momin, Rahmat Ali, Abdul Naeem, Afsar Khan
Abstract
Emerging contaminants (ECs) include both natural and man-made compounds that have recently been found to be present in wastewater and have a harmful effect on human health and aquatic environment. Several ECs such as pharmaceuticals, antibacterial, hormones, synthetic dyes, flame retardants are directly or indirectly discharged from hospitals, agricultural, industrial and other sources to the environment. Strategies have been developed to overcome the challenges faced by contaminated water treatment technologists. Advanced treatment technologies such as physical, chemical, and biological methods have been studied for ECs removal as well as for reduction of effluents levels in discharged water. Techniques such as membrane filtration, adsorption, coagulation-flocculation, solvent extraction, ion exchange, photodegradation, catalytic oxidation, electrochemical oxidation, ozonation and precipitation, etc., have been investigated. Based on past research, these techniques significantly remove one or more pollutants but are insufficient to remove most of the toxic contaminants efficiently from wastewater. Nanomaterial incorporated technologies may be a proficient approach for removing different contaminants from wastewater. These technologies are costly because of high-energy consumption during the treatment of wastewater for reuse on large scale. Consequently, comprehensive research for the improvement of wastewater treatment techniques is required to obtain complete and enhanced EC removal by wastewater treatment plants.