CAS Key Laboratory of Urban Pollutant Conversion, Institute of Urban Environment, Chinese Academy of Sciences, Xiamen, 361021, China; University of Chinese Academy of Sciences, Beijing, 100049, China.
CAS Key Laboratory of Urban Pollutant Conversion, Institute of Urban Environment, Chinese Academy of Sciences, Xiamen, 361021, China.
Chemosphere. 2020 Dec;260:127632. doi: 10.1016/j.chemosphere.2020.127632. Epub 2020 Jul 14.
In this study, the incineration fly ash (IFA) of municipal solid waste (MSW) and municipal sewage sludge (MSS) was synergistically subjected to hydrothermal treatment coupled with pyrolysis (HTP). The regulation of Cl removal and the destruction and detoxification of polychlorinated dibenzo-p-dioxins and polychlorinated dibenzofurans (PCDD/Fs) were investigated. The results demonstrated that during hydrothermal treatment (HTT), the Cl removal rate increased with temperature, most of the soluble chlorides were removed, and the acid dissolution of Cl in the hydro-residue was significantly reduced. At hydrothermal temperatures exceeding 180 °C, the variation in the Cl removal rate decreased. Although a certain quantity of PCDD/Fs dissolved in the hydrothermal liquid, the total destruction rate achieved by HTT remained more than 90%. The detoxification rate did not exceed 60% owing to the formation of low-chlorinated PCDD/Fs. Subsequent pyrolysis of the hydro-residue further improved the Cl removal rate, which increased with pyrolysis temperature; the Cl content of pyro-char was reduced to 1.8% and that of the leached acid was less than 0.5 mg/g at 800 °C. In addition, PCDD/Fs in tar and pyrolysis gas were not detected under optimal conditions; the PCDD/F concentration of pyro-char was reduced to 0.17 ng I-TEQ/kg. The destruction and detoxification efficiencies of PCDD/Fs reached 98.49% and 92.50%, respectively. Thus, the method of HTP was conducive to the co-disposal of IFA and MSS.
在这项研究中，城市固体废物（MSW）和城市污水污泥（MSS）的焚烧飞灰（IFA）协同进行了水热处理与热解（HTP）。研究了 Cl 的去除调节以及多氯二苯并对二恶英和多氯二苯并呋喃（PCDD/Fs）的破坏和解毒。结果表明，在水热处理（HTT）期间，Cl 的去除率随温度升高而增加，大部分可溶性氯化物被去除，水热残渣中 Cl 的酸溶解显著降低。在水热温度超过 180°C 时，Cl 去除率的变化减小。尽管一定量的 PCDD/Fs 溶解在水热液体中，但 HTT 实现的总破坏率仍超过 90%。由于形成低氯代 PCDD/Fs，解毒率未超过 60%。随后对水热残渣进行热解进一步提高了 Cl 去除率，该去除率随热解温度的升高而增加；在 800°C 时，热解炭的 Cl 含量降低至 1.8%，浸出酸的 Cl 含量低于 0.5mg/g。此外，在最佳条件下，焦油和热解气中未检测到 PCDD/Fs；热解炭中的 PCDD/F 浓度降低至 0.17ng I-TEQ/kg。PCDD/Fs 的破坏和解毒效率分别达到 98.49%和 92.50%。因此，HTP 方法有利于 IFA 和 MSS 的共处置。
