Advances in water treatment technologies for removal of polycyclic aromatic hydrocarbons: Existing concepts, emerging trends, and future prospects

Abstract

In the last two decades, environmental experts have focused on the development of several biological, chemical, physical, and thermal methods/technologies for remediation of PAH‐polluted water. Some of the findings have been applied to field‐scale treatment, while others have remained as prototypes and semi‐pilot studies. Existing treatment options include extraction, chemical oxidation, bioremediation, photocatalytic degradation, and adsorption (employing adsorbents such as biomass derivatives, geosorbents, zeolites, mesoporous silica, polymers, nanocomposites, and graphene‐based materials). Electrokinetic remediation, advanced phytoremediation, green nanoremediation, enhanced remediation using biocatalysts, and integrated approaches are still at the developmental stage and hold great potential. Water is an essential component of the ecosystem and highly susceptible to PAH contamination due to crude oil exploration and spillage, and improper municipal and industrial waste management, yet comprehensive reviews on PAH remediation are only available for contaminated soils, despite the several treatment methods developed for the remediation of PAH‐polluted water. This review seeks to provide a comprehensive overview of existing and emerging methods/technologies, in order to bridge information gaps toward ensuring a green and sustainable remedial approach for PAH‐contaminated aqueous systems. Practitioner points Comprehensive review of existing and emerging technologies for remediation of PAH‐polluted water. Factors influencing efficiency of various methods, challenges and merits were discussed. Green nano‐adsorbents, nano‐oxidants and bio/phytoremediation are desirous for ecofriendly and economical PAH remediation. Adoption of an integrated approach for the efficient and sustainable remediation of PAH‐contaminated water is recommended.

TiO2 Photocatalysis for the Transformation of Aromatic Water Pollutants into Fuels

“…As outlined beforehand, toxic organic pollutants are widespread in the environment, thus, it is highly recommended to eliminate or reduce the concentration of such pollutants in the aquatic environment to safe levels [53,[80][81][82][83]. Numerous conventional treatment processes have been applied and tested for wastewater treatment, such as adsorption, coagulation, precipitation, biodegradation, ozonation, electrochemical oxidation, and advanced oxidation processes [43,47,[83][84][85][86][87][88].…”

Sustainable development and enhancement of cracking processes using metallic composites

“…However, the emergence of N-doped carbonsupported metal catalysts in the last decade has attracted significant attention in catalysis, and the fact that nitrogen doping can be tailored to induce other characteristics to the bulk material, other than catalysis, encourages an integrated and sustainable approach to material development [1][2][3]. Integrated approaches include catalysis-adsorption, oxidation-catalysis, photocatalysis-degradation, photodegradation-adsorption, etc., achieved with the same functionalized material/composite [117,[120][121][122]. N-doped carbon-supported metal supports have shown higher catalytic efficiency in several heterogeneous catalytic reactions, than the conventional, pristine carbon supports [3].…”

Naphthalene degradation studies using Pseudomonas sp. strain SA3 from Alang-Sosiya ship breaking yard, Gujarat

“… Adeola and Forbes (2020) have discussed technologies like solvent extraction, phytoremediation, chemical oxidation, photocatalytic degradation, electrokinetic, thermal treatment, microbial degradation and integrated remediation technologies. These methods come along with limitations such as high costs, production of toxic by-products and the genesis of a newer pollutant that may affect the environment.…”