Effect of NaClO disinfectant treatment on the yields, components and combustion characteristics of typical medical waste pyrolysis products

Abstract

Medical waste with pathogenic bacteria is infectious and toxic, which could cause significant harm to the environment and human health without being adequately disposed of. Pyrolysis-incineration coupled technology can realize the rapid and efficient treatment of medical waste while reducing the generation of pollutants. Whereas, the NaClO disinfection treatment, which is a necessary process prior to transfer and disposal of medical waste, has not been sufficiently described in terms of its effect on the pyrolysis yield and components characteristics of medical waste. This study clarified the influence mechanism of NaClO disinfection treatment on the yields, components, and combustion characteristics of pyrolysis products derived from typical medical waste (cotton swab sticks, masks, and latex gloves). The results showed that NaClO disinfection treatment induced depolymerization of the internal structure of the polymer and increased pyrolysis tar and syngas at 400 °C. In addition, NaClO disinfection treatment reduced syngas quality, which was attributed to generating more CO2 and inhibiting alkynes gas production under medium-low pyrolysis temperatures. Furthermore, the condensation or cyclization of light components into heavy components in the tar increased the average double-bond equivalents and oxygen content, which was detrimental to tar ignition and combustion. Moreover, the combustion performance of char was improved because there was a tendency for the conversion of graphitic carbon to fatty carbon in the char. These findings elucidate the feasibility of pyrolysis-incineration coupled technology for the fast and effective treatment of medical waste.