Partitioning and removal behaviors of PCDD/Fs, PCBs and PCNs in a modern municipal solid waste incineration system
Partitioning and removal behaviors of PCDD/Fs, PCBs and PCNs in a modern municipal solid waste incineration system
复制标题
现代城市生活垃圾焚烧系统中PCDD/Fs、PCBs和PCNs的划分和去除行为
DOI：
10.1016/j.scitotenv.2020.139134
复制
发表时间：
2020
影响因子：
9.8
通讯作者：
Zhang Haijun
中科院分区：
文献类型：
--
作者：
Ren Meihui;Lv Zhenzhong Yang;Xu Lin;Lu Qiqi;Zhang Xuefeng;Yu Ying;Fan Yun;Gao Yuan;Chen Jiping;Zhang Haijun
对一个现代化的大型城市生活垃圾焚烧系统进行了广泛的评价，以表征高毒性氯代芳烃、多氯二苯并二恶英和二苯并呋喃（PCDD/Fs）、多氯联苯（PCBs）和多氯萘（PCNs）在燃烧后区的分布及其相应的质量通量。结果表明，氯代芳烃的正辛醇-空气分配系数（KOA）可以很好地描述其在烟气/飞灰中的分配行为，且受烟气温度的影响较大。锅炉段形成的氯代芳烃93%以上被分配到烟气中，并输送到后续的烟气净化系统，烟气中92%以上的Cl 3 -8DDs、Cl 3 - 7 DFs、Cl 5 - 10 Bs和Cl 4 - 8 Ns被飞灰排放去除。质量通量计算结果表明，烟气净化系统中的记忆效应显著提高了氯代芳烃的排放水平，尤其是低氯代芳烃。记忆效应主要是由沉积颗粒介导的直接氯化机理引起的。此外，活性炭的注入会导致PCBs排放量的明显增加.研究结果为进一步减少高毒性氯代芳烃的排放提供了重要的理论依据。
An extensive evaluation on a modern full-scale municipal solid waste incineration system was conducted for characterizing the distribution of highly toxic chlorinated aromatics, polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs), polychlorinated biphenyls (PCBs) and polychlorinated naphthalenes (PCNs), and their corresponding mass fluxes in post combustion zone. It was found that the flue gas/fly ash partitioning behaviors of chlorinated aromatics could be essentially described by their octanol-air partition coefficients (KOA) and strongly affected by the flue gas temperature. Above 93% of chlorinated aromatics formed in boiler section was partitioned into the flue gas and transported into the subsequent flue gas cleaning system, in which above 92% of Cl3–8DDs, Cl3–7DFs, Cl5–10Bs and Cl4–8Ns in flue gas was removed by the discharge of fly ash. The results of mass flux calculation indicated that the memory effect in flue gas cleaning system remarkably elevated the emission levels of chlorinated aromatics, especially the less chlorinated ones. The memory effect should mainly result from the direct chlorination mechanism mediated by the deposited particles. In addition, activated carbon injection could cause an obvious increase in PCBs emission. The obtained results provided some important implications for further reducing the emission of highly toxic chlorinated aromatics.