关键词: 生活垃圾焚烧飞灰, 矿化反应, CO₂封存, 响应面曲线法, 浸出毒性

Abstract: In order to realize the resource utilization of municipal solid waste incineration fly ash (MSWIFA), the direct wet mineralization carbon sequestration performance of MSWIFA was studied by single factor method and response surface methodology, and the maximum CO2 sequestration ratio was obtained. In addition, BCR speciation analysis and toxic leaching test were used to evaluate the environmental risk of heavy metals before and after the mineralization of MSWIFA. The results showed that, with the increase of reaction temperature, initial pressure, reaction time and liquid-solid ratio, the CO₂ sequestration ratio first increased and then decreased, and at the optimized condition of each single factor, the maximum CO₂ sequestration ratio were 16.71%, 15.80%, 15.36% and 14.96% at 105 ℃, 2.0 MPa, 1.5 h and 20 mL/g, respectively. Based on the response surface method, the optimal reaction conditions were obtained as follows:a pressure of 0.5 MPa, a temperature of 99.19 ℃, a reaction time of 1 h,a liquid-solid ratio of 25 mL/g, and the maximum CO2 sequestration ratio was 12.91%;after the mineralization reaction, the oxidizable form of As and Pb in the MSWIFA was transformed into residual form, the oxidizable form of Ba was transformed into reducible form, the residual and oxidizable form of Zn was transformed into reducible and acid soluble forms, and the oxidizable form of Cd was transformed into residual and reducible forms.

Key words: municipal solid waste incineration fly ash, mineralization reaction, CO₂ sequestration, response surface methodology, leaching toxicity