Sorptive removal versus catalytic degradation of aqueous BTEX: a comprehensive review from the perspective of life-cycle assessment

Abstract

Benzene, toluene, ethylbenzene, and xylene (BTEX) are commonly encountered industrial contaminants. The high consumption and unregulated discharge of carcinogenic BTE and neurotoxic X have heavily impacted the environment and water quality. Sorptive separation of BTEX from the aqueous phase is cost-effective and easy to operate; however, slower uptake, adsorbent saturation, and complexity in sorbent regeneration are primary limitations. Advanced oxidation processes (AOPs) offer faster kinetics, reusability, and better efficiency to eliminate BTEX. However, the economics, sustainability, and large-scale extensibility of AOPs need to be verified. In this context, the current review discusses recent developments in aqueous BTEX removal by sorption and AOPs. Life cycle assessment (LCA) analysis of various treatment technologies was carried out to verify the environmental compliances of the process. Based on the single point score, the sustainability ranking of the treatment technologies was: adsorption (Ads.) (0.48), ozonation (1.90), electrochemical oxidation (EO) (4.82), photocatalysis (5.43), Fenton's (7.87), ultrasound-peroxymonosulphate (US-PMS) (31.8), acoustic cavitation (AuC) (228), and hydrodynamic cavitation (HdC) (245). The lower the impact score, the higher is the sustainability of the technology to treat BTEX. Overall, this review identifies the research gaps and boosts the researchers to find out the feasibility of the proposed suggestion to minimize the pollution of hazardous BTEX.