The inhibition mechanism of VOCs and heavy metals in carbon dots synthesis wastewater

초록

Carbon dots (CDs), as eco-friendly nanomaterials, have been widely applied in environmental pollution remediation. However, the environmental issues associated with their synthesis, particularly when derived from solid waste, cannot be overlooked. During the preparation process, significant amounts of volatile organic compounds (VOCs) and heavy metals are released, posing potential ecological risks. Moreover, the inhibition mechanism between the resulting CDs and pollutant emissions under varying reaction conditions remains poorly understood. In this study, CDs were synthesized via hydrothermal carbonization of waste wood chips and rubber powder. The effects of key preparation parameters, including solvent composition, temperature, and holding time, on both CDs performance and the suppression of VOCs and heavy metal emissions in the byproduct wastewater were systematically investigated. We identified optimal synthesis conditions that simultaneously maximize CDs performance and minimize pollution release. Specifically, the highest fluorescence quantum yield, zeta potential, and effective pollutant suppression were achieved using a composite solvent system at 280 degrees C with a 4-hour holding time, while maximum fluorescence intensity and yield were obtained after 6 h. Through this "performance-environmental impact" dual-evaluation framework, we elucidated the co-evolution patterns and underlying mechanisms governing product properties and environmental loads under different synthesis conditions. This work provides essential data and a theoretical foundation for achieving an optimal balance between material performance and environmental sustainability in the resource utilization of solid waste.

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