Review on polycyclic aromatic hydrocarbons (PAHs) migration from wastewater

Abstract

Rapidly increasing global population and increased civilization has increased burden on potable water resources and results in larger volumes of wastewater. Physical wastewater management techniques has advanced for domestic usage and commercial effluent new conceptions about imminent wastewater treatment have been acclaimed for highly carcinogenic polycyclic aromatic hydrocarbon (PAH) compounds. The present review study emphasis on the assessment of several accessible PAHs treatment methods used in wastewater management. The elementary principles, contextual remediation mechanisms and recent development in PAHs removal practices have also been precisely explained. The comprehensive information regarding sources, dispersal, classification, physicochemical properties, PAHs toxicity for humans and aquatics life, conventional treatment procedures, and advanced oxidation processes specified can assist us to identify the PAHs problem and their intensity. The performance evaluation of different removal techniques are discussed in details and found that highest PAHs' reduction for 5-or 6-ring (99%,) while 3-ring (79% reduction) with oxidant dose of 1.64 mL/L using titanium catalyst. In case of MWTPs, with secondary techniques, the average removal efficiency found in the range of 81.1-92.9% while for AOPs are 32-99.3%. Here, overall yield through AOPs most suitable if process used with some catalyst enhanced the yield as well and suitable for high ring as well as low ring PAHs. Among various processes, advanced oxidation and catalytic oxidation processes are the most valuable and promising techniques for PAHs removal. Based on the given evidences, the AOPs coupled with catalysts have been decided as the most competent design for wastewater PAHs treatment.

Keywords: Advanced oxidation process; PAHs; performance evaluation; wastewater.