This study focuses on removing naphthalene, a carcinogenic polycyclic aromatic hydrocarbon, from wastewater through an economical and environmentally friendly method. Naphthalene, frequently found in coal tar and crude oil, presents a significant contamination risk in steel industry wastewater. In developing countries such as India, levels of naphthalene in water often exceed permissible limits, necessitating effective treatment solutions. The effectiveness of a vertical flow-constructed wetland on a laboratory scale was evaluated for naphthalene removal, utilizing Vetiver grass and Light Weight Expanded Clay Aggregate (LECA). Vetiver, a cost-effective and eco-friendly adsorbent, provides slope stabilization, soil erosion prevention, and flood and landslide mitigation benefits. LECA was selected due to its resilience, reusability, sustainability, and high hydraulic conductivity (1.15 × 10⁻3 m/sec). A 95% removal efficiency was achieved under optimal conditions, which included 10 g/L of LECA and a 30-min contact duration for an initial naphthalene concentration of 12 mg/L. The pseudo-second-order model (R2 = 0.9879) and the Freundlich model (R2 = 0.9956) provided the best fit for the kinetics and isotherm data. In a one-dimensional vertical column study, naphthalene was removed using a 30 mm deep saturated LECA bed within three days. Additionally, a laboratory-scale wetland model utilizing LECA and pure sand (1.18 mm and 4.75 mm) incorporating vetiver achieved a 97.48% reduction in naphthalene levels. Results from the CW2D, a two-dimensional constructed wetland module from the Hydrus solute transport software package, corroborated experimental data. These results suggest that treating naphthalene-contaminated industrial effluents with Vetiver and LECA in constructed wetlands may be a viable, sustainable, and environmentally benign approach.