Polycyclic aromatic hydrocarbons represent a major class of persistent environmental contaminants characterized by high chemical stability, lipophilicity, and toxicity. Among these, high molecular weight compounds like benzo[ghi]perylene are frequently discharged into aquatic systems via vehicle exhaust residues washed off during routine automobile cleaning. Traditional wastewater treatment strategies often struggle to eliminate these stubborn lipophilic pollutants effectively or generate harmful secondary byproducts. Consequently, developing efficient, low-cost adsorption technologies utilizing locally available biomassBiomass is a complex biological organic or non-organic solid product derived from living or recently living organism and available naturally. Various types of wastes such as animal manure, waste paper, sludge and many industrial wastes are also treated as biomass because like natural biomass these More waste has emerged as a vital environmental priority.

To address this challenge, discarded eucalyptus wood waste was converted into biochar via nitrogen-atmosphere pyrolysisPyrolysis is a thermochemical process that converts waste biomass into bio-char, bio-oil, and pyro-gas. It offers significant advantages in waste valorization, turning low-value materials into economically valuable resources. Its versatility allows for tailored products based on operational conditions, presenting itself as a cost-effective and efficient More at four-hundred-fifty degrees Celsius, followed by hydrochloric acid activation to enhance surface reactivity. Comprehensive material characterization using scanning electron microscopy, transmission electron microscopy, Fourier transform infrared spectroscopy, and surface area analysis revealed a highly porous structure interspersed with abundant oxygen-containing functional groups. These structural features facilitate contaminant capture through a combination of pore filling, hydrophobic interactions, pi-pi stacking between aromatic domains, and van der Waals forces.

Batch adsorption experiments evaluating various operational parameters demonstrated that contaminant removal is heavily governed by solution chemistry and thermodynamic conditions. Raising the temperature to sixty degrees Celsius enhanced molecular mobility and mass transfer, while adjusting the solution pH to six optimized surface interactions near the material’s zero charge point characteristics. Furthermore, regeneration studies confirmed that the spent biochar can be effectively desorbed using dilute hydrochloric acid and reused across multiple successive cycles with only minor declines in performance, underscoring its practical viability for wastewater remediation.

Source: Hasan, M. A. (2026). Adsorptive removal of benzo(ghi) perylene from vehicle-wash wastewater using eucalyptus wood waste-derived biochar. Scientific Reports, 16(1), Article in Press.