市政污泥掺烧对生活垃圾焚烧设施烟气中污染物排放的影响

与生活垃圾协同焚烧是污泥处置中最有前景的处置方式,但其对焚烧烟气污染物排放的影响尚未明确。利用生活垃圾焚烧炉开展生活垃圾协同处置市政污泥的试验,研究掺烧5%、10%和15%的市政污泥时焚烧烟气中酸性气体、烟尘、重金属和二噁英等的排放特征。结果表明:与单独焚烧生活垃圾的对照组相比,在各掺烧比例下,烟气中SO_2、HCl、NO_x及烟尘有一定程度的增加,但均未超过GB18485—2014《生活垃圾焚烧污染控制标准》限值;Cu、Hg排放质量浓度明显下降,Cr、Cd波动下降,Pb在高掺烧比时仍远低于限值,Ni增长幅度小于15%;二噁英总量升高,但仍符合标准限值。因此,在掺烧比例不超过15%的情况下,焚烧烟气中污染物排放仍在安全可控范围。

Gaseous pollutant emissions from the mixed combustion of the municipal solid waste incinerator with sewage sludge

In this paper,the authors intend to present his study experience with the sewage sludge co-combustion experiments in the municipal solid waste incinerators,with the respective ratios of sludge mass at about 5％,10％ and 15％ added to the respective testing groups,for,as is already known,such co-combustion is regarded as a promising way to deal with the municipal sewage sludge,though the actual impact on the pollutant discharge from the flue gas remains unknown. At the same time,the emission characteristics of the acid gases,smoke,heavy metal left-overs and dioxin in the flue gas in the different testing groups are supposed to be liable to provide basic data for generalizing the cocombustion technology. The results of our experiments prove that the concentrations of SO2,HCl,NOx and the particles in the flue gas have been slightly increased in the experimental groups,as compared with the control group in which the municipal solid wastes were made to burn separately. Thus,all the concentrations of such pollutants would remain still lower than their limits in the"Standard for Pollution Control on the Municipal Solid Waste Incineration (GB 18485-2014) ". In such a case,the concentrations of Cu and Hg may turn to get remarkably reduced noticeably in the experimental groups,while the concentrations of Cr and Cd may turn to be declining with the fluctuation going on. On the contrary,the concentrations of Pb and Ni would rise gradually with the increase of sludge ratio,whereas the concentration of Pb in the test group with sludge adding ratio of 15％ remains still lower than the maximum limit of the standard. In the similar manner, the total concentrations of dioxin may also be increased with the rise of the sludge ratio,though they may still stay within the maximum limit within the standard. What is more,the rising rate of the concentration of Ni may not go beyond 15％. Therefore,it can be concluded that when the increasing ratio of the sewage sludge to MSW under 15％,it wouldn't be possible for the pollutant emissions of the flue gas to increase significantly,and all the concentration rates would remain lower than the maximum limit within the secure and controllable range.