State Key Laboratory for Clean Energy Utilization, Institute for Thermal Power Engineering, Zhejiang University, Hangzhou 310027, China.
State Key Laboratory for Clean Energy Utilization, Institute for Thermal Power Engineering, Zhejiang University, Hangzhou 310027, China.
Chemosphere. 2018 Oct;208:176-184. doi: 10.1016/j.chemosphere.2018.05.161. Epub 2018 May 28.
Mechanochemical degradation (MCD) is employed for the dechlorination of polychlorinated dibenzo-p-dioxins (PCDD) and -furans (PCDF) in filter ashes from municipal solid waste incinerators, respectively with the assist of six additive systems. The evolution of PCDD/F-signatures in all eleven samples are systematically monitored and studied at the level of individual congeners, and special attention is paid to CP-route congeners, 2,3,7,8-substitution, 1,9-substitution, and 4,6-PCDF. The PCDD/F-isomers distribution follows an analogous pattern, indicating the similar acting mechanism for all additives: additives transfer electrons to attack the CCl bond and then expulse chlorine. MC dechlorination is not favored for the chlorine on β-position (2,3,7,8-position). The oxygen with stronger electronegativity in PCDD/Fs negatively influences CCl bond to accept donated electrons, hindering the removal of chlorine on 1,9-position for PCDD, and chlroine on 4,6-position for PCDF. Finally, two fair dechlorination pathways for PCDD and PCDF are respectively proposed based on the detailed analysis of CP-route congeners. The evolution of PCDD-signatures is clear, yet obscure for PCDF-signatures, which still requires further investigations.
机械化学降解（MCD）分别用于城市固体废物焚烧炉过滤器灰烬中多氯二苯并对二恶英（PCDD）和多氯二苯并呋喃（PCDF）的脱氯，各有六个添加剂系统辅助。在所有 11 个样品中，系统地监测和研究了个别同系物水平上的 PCDD/F 特征的演变，并特别关注 CP 途径同系物、2,3,7,8 位取代、1,9 位取代和 4,6-PCDF。PCDD/F-异构体的分布遵循类似的模式，表明所有添加剂的作用机制相似：添加剂将电子转移以攻击 CCl 键，然后逐出氯。MC 脱氯不利于β位（2,3,7,8 位）上的氯。PCDD/Fs 中电负性更强的氧负性影响 CCl 键以接受供体电子，阻碍 PCDD 上 1,9 位的氯和 PCDF 上 4,6 位的氯的去除。最后，根据 CP 途径同系物的详细分析，分别提出了两种用于 PCDD 和 PCDF 的合理脱氯途径。PCDD 特征的演变很明显，而 PCDF 特征的演变则不明显，这仍需要进一步研究。
