Reciclagem de placas eletrônicas de dispositivos eletrônicos para fumar na síntese de catalisador para degradação de corante

Abstract

Electronic smoking devices (ESDs), popularly known as electronic cigarettes, have become one of the main emerging waste types due to their increasing consumption and improper disposal, containing toxic substances such as nicotine, heavy metals, plastics, and lithium-ion batteries. The lack of regulations regarding the disposal and recycling of this waste in Brazil aggravates its environmental impacts. In this context, this study proposed the recycling of electronic boards from electronic cigarettes seized by the Federal Police for the production of a catalyst through the hydrothermal carbonization (HTC) technique, using rice husk as a complementary biomass. The objective was to evaluate the efficiency of this material in the degradation of the turquoise remazol dye and to investigate the phytotoxicity of the treated effluent through a bioassay with Allium cepa seeds. The electronic components and rice husk were previously ground and sieved, then subjected to HTC at 180 °C for 8 hours. The resulting hydrochar was activated by acid washing and applied in degradation assays using hydrogen peroxide (H₂O₂) and peroxydisulfate (PDS) as oxidizing agents. Low degradation efficiency was observed in the presence of H₂O₂, with only 5.08% actual dye removal, possibly due to limited catalytic interaction with the hydrochar. In contrast, the use of PDS resulted in higher efficiency, reaching 77.47% removal, indicating greater oxidative potential of the system. Nevertheless, the treated effluent exhibited high phytotoxicity, completely inhibiting the germination of Allium cepa seeds in all treatments. The presence of fungi after five days may have partially influenced the results, but the marked difference compared to the control confirms the toxic potential of the intermediates formed during the oxidative process. These findings demonstrate that recycling ESDs can yield materials with environmental applications; however, the degradation pathway studied still requires adjustments to improve catalytic efficiency and reduce the toxicity of the treated effluents.