市政污泥与生活垃圾协同焚烧的二噁英排放特征及毒性当量平衡

于2016年5月和2017年1月，分别对南方某生活垃圾焚烧发电厂开展生活垃圾与市政污泥(分别为0%、5%、10%和15%)协同焚烧试验，探讨市政污泥掺烧对生活垃圾焚烧过程中PCDD/Fs排放的影响.在不同季节中，PCDD/Fs均主要分布于飞灰与炉渣中.受焚烧过程中PCDD/Fs的结构破合与重组的影响，废渣中以2, 3, 4, 7, 8-PeCDF (13.0%~72.1%)单体为主. 2016年5月，每吨焚烧原料(指生活垃圾跟污泥的混合物)混合焚烧排放的PCDD/Fs毒性当量比原料本身含有的增加了14.1~29.2 μg TEQ/t，而2017年1月则降低了9.2~9.9 μg TEQ /t.生活垃圾焚烧过程中加入市政污泥能够提高焚烧材料中的硫元素与氯元素的质量比，从而抑制PCDD/Fs的再合成.综上所述，在保证生活垃圾焚烧发电厂的电力生产条件下，适当的市政污泥与生活垃圾协同焚烧能够降低焚烧过程中的PCDD/Fs排放，从而实现市政垃圾污泥的安全处理处置.

PCDD/Fs Emission and Toxic Equivalent Balance of Municipal Sewage Sludge Cocombustion in a Solid Waste Incinerator

The influence of municipal sewage sludge (MSS) on the discharge of PCDD/Fs in the process of munici-pal solid waste (MSW) combustion is discussed. The co-incineration tests of MSW and MSS (0%, 5%, 10% and 15%, respectively) were carried out in a MSW incineration in southern China in May 2016 (wet season) and Jan 2017 (dry season). The PCDD/Fs were mainly distributed in flying ash in the wet season and in the slag in the dry season. The emission of PCDD/F per ton of raw material after incineration was 14.1~29.2 μg TEQ /t higher than that in the raw material in the wet season and was 9.2~9.9 μg TEQ /t lower in the dry season. The PCDD/Fs congener profiles were dominated by 2, 3, 4, 7, 8-PeCDF (13.0%~72.1%) in the output discard in both seasons, which can be attributed to the decomposition and recombination of PCDD/Fs. The added MSS during MSW co-incineration represses the production of PCDD/Fs due to the higher ratio of sulfur to chlorine in the incineration materials. Therefore, MSS can be an ideal candidate for MSW disposal under appropriate management.