Treatment of industrial wastewater via zeolite LTA fabricated from aluminosilicate contaminated with polycyclic aromatic hydrocarbons

The regeneration of spent motor oil using aluminosilicate adsorbents is a commercially established method for mitigating environmental contamination by toxic compounds. However, this process generates substantial quantities of solid waste contaminated with polycyclic aromatic hydrocarbons (SW-PAHs), which accumulate in refinery landfills and require careful management. The present study introduces an innovative approach for the efficient conversion of this residual waste into LTA-type zeolite, intended for use in wastewater treatment, specifically targeting the remediation of zinc-contaminated industrial effluent. Structural transformation of SW-PAHs was achieved through the incorporation of aluminum hydroxide and boehmite, which facilitated the hydrothermal conversion of the amorphous precursor into a mesoporous zeolite framework. The powdered material derived from a precursor containing 25% boehmite, following fusion at 800 °C, exhibited a maximum Zn²⁺ adsorption capacity of 126.6 mg g⁻¹, a value comparable to that of commercial LTA zeolite. Ultimately, the proposed process contributes to the safe utilization of hazardous components, the conservation of natural resources, and provides practical insights into the targeted fabrication of LTA zeolite, thereby offering a cost-effective and sustainable solution.