Remediation of Polycyclic Aromatic Hydrocarbons (PAHs) in Coastal Subsurface Water by an Optimized Multilayer Ceramic Composite Superhydrophobic Membrane

Abstract

Ceramic-composite membrane-based processes emerge as an attractive choice for removal of polyaromatic hydrocarbons (PAHs) from coastal subsurface water. This study is primarily based on the development of a multilayer superhydrophobic composite membrane supported on mullite and rejection efficiency analysis of polyaromatic hydrocarbons from contaminated water. Groundwater samples collected from two different locations in Sundarban coastal areas revealed the presence of high levels of Na⁺, Cl^–, and various metal oxides along with the main contaminant PAHs (6.96–11.24 μg/mL). While the developed composite membranes could effectively remove divalent and multivalent ions, monovalent ions were separated less favorably. The removal efficiency increased with rising transmembrane pressure, achieving up to 97.55% for mildly PAH-contaminated water (6.96 μg/mL). Experimental removal rates were useful for developing predictive models, suggesting that the Spiegler–Kedem–Katchalsky-Film Theory model was suitable for describing PAH rejection in mildly contaminated water, whereas the Film Theory-Extended Nernst–Planck Equation Model better predicted PAH rejection in highly contaminated water. The developed membrane showed structural and PAH removal integrity for up to 50 days of prolonged exposure to contaminated water, depicting excellent durability and revealing the reciprocal interaction among pore statistics, removal rate, and fouling models.