Abstract

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Bioremediation technology plays a crucial role in ensuring ecological security when addressing petroleum hydrocarbon contamination in the environment. Its advantages include cost-effectiveness, high efficiency, minimal environmental impact, and the absence of secondary pollutants. Recently, carbon dots (CDs) have gained attention due to their exceptional properties, including quantum size, strong light absorption, tunable luminescence, high quantum yield, biocompatibility, low toxicity, and environmental friendliness. This study aims to evaluate the effectiveness of carbon dots in combination with microbial culture for the remediation of hydrocarbon-contaminated soil. Soil analysis revealed that the contaminated sample was acidic (pH 5.75±1), whereas the control sample had an alkaline pH of 7.84±1. Carbon dots synthesized using biomass was characterized via Transmission Electron Microscopy and Energy Dispersive X-ray, showing a particle size of 10 nm and elemental composition. The synthesized CDs exhibited photoluminescence under ultraviolet light. A bacterial consortium consisting of Bacillus thuringiensis, Bacillus velezensis, and Stenotrophomonas species was used to stimulate biodegradation.Gas Chromatography-Flame Ionization Detector (GC-FID) analysis over 86 days (sampled every four weeks) revealed a significant reduction in Total Petroleum Hydrocarbon (TPH). Carbon dots (CD) alone had an insignificant TPH value of (1.37±2), while microbial culture (MC) had (13.90±7).The study confirms that combining carbon dots with microbial culture significantly enhances hydrocarbon degradation in contaminated soil.

Keywords: Biostimulation, Carbon dot, Transmission Electron Microscope, Energy dispersive X-Ray