Abstract
An estimated 2.73×1012 gallons of water are generated annually in the automotive sector, resulting in complex wastewater streams. Pollutant-free water from this sector is essential for a safe environmental footprint for various applications, as wastewater causes corrosion, equipment blockages, and increased chemical costs via vehicle wash bays, paint/coating shops, plating lines, and coolant handling, mapping nanomaterial functions to automotivetypical contaminants (oils/greases, surfactants, dyes, heavy metals: Pb, Cu, Zn, and Cr). Average water-contaminant loads, including grease and oil (1100 mg.L-1), COD (4500 mg.L-1), and overall suspended solids (3500 mg.L-1), create some level of health risk, and treatment methods have shifted from the physical techniques of gravity separation, dissolved air flotation, and demulsification, which involve nanotechnology, to hybridization. With a perwash prediction of globally used vehicles in 2015, 218 billion liters of wastewater run off to potential water streams, initiating water-nanoparticle mobility before it can be treated for re-use. Based on their high surface-to-volume ratio, nanoscale size, ordered structure, and filtration competence resulting from their inherent mechanical, thermal, antifouling, and antibacterial properties, nano-engineered materials, including nano-adsorbents, nanomembranes, and nano-catalysts, are specifically used to overcome the limitations of conventional wastewater treatment methods. Oil-based wastewater treated with magnetic sorbent nanoparticles acts as an emulsifier, thereby containing microbes and causing microorganism-infested wastewater. Therefore, an effective means of treating wastewater with a variety of compositions is nanoenhanced bioremediation. Hence, a nanotechnology technique that fuses bioremediation and nano-remediation to achieve nano-enhanced bioremediation for completely enhanced wastewater remediation is proposed to abate environmental pollution. However, long-term risks and lifecycle assessments of nanomaterial deployment in wastewater treatment will further validate the degree of trade-off between its specific automotive service applications and safety, with regulatory frameworks to meet longterm sustainability goals.