污泥掺烧对焚烧后固体废物污染物排放的影响

在佛山某生活垃圾焚烧发电厂开展生活垃圾掺烧市政污泥工业试验,分析5%、10%、15%的市政污泥掺烧对电厂焚烧后固体废物中重金属和二噁英排放的影响。结果表明,掺烧污泥使Cd在飞灰中的分布提高了40%以上,但其他重金属的分布特征仍主要受各自沸点的影响。焚烧固废中重金属含量受污泥的引入影响普遍不显著,飞灰中Cu浸出质量浓度上升20%,Ni、Pb、Hg、Cr的浸出质量浓度波动下降;炉渣中重金属浸出质量浓度波动较大。焚烧飞灰中总二噁英含量与污泥掺烧比例成负相关,且与投料中的Cl质量分数成正相关,与S质量分数成负相关。因此,低于15%的污泥掺烧比例不会显著提升焚烧固废中污染物排放浓度。

Influence of the municipal solid residue on the municipal solid waste emission

The present article is aimed at making an investigation of the impact of the municipal solid residue on the total emission of the municipal solid waste (short for MSW).As is known,there exist large amounts of leachable heavy metals and other toxic equivalents (TEQ) dioxins in the said waste.The present author has first of all done a commercial test in the respect of the cocombustion products as regard to the sludge and MSW in a MSW incineration power plant in Foshan city,affiliated to Guangdong administration,so as to pursue the impact of the solid sludge on the pollutant content rate of the incineration residues.In the process of our investigation and examination,we have added a certain ratio of sludge mass at about 5％,10％ and 15％ to each testing group,respectively.And,then,an analysis has been done of the heavy metal concentration rates and the leaching features in addition to the TEQ dioxins in the residues left over from the aforementioned incineration examinations.Furthermore,the mass balance of the heavy metal and the dioxins in their own corresponding correlation with the dioxins and Cl,S has also been properly analyzed.This newly made analysis shows that,in the co-combustion process,over the 40％ of the content of Cd in the fly ash has been increased to the original mass amount,though the distributive content concentration rates of the other heavy metal residues remain dominated by their own boiling points,which is much similar to those of the control group.What is more,the concentration rates of the heavy metal contents in the residue tend be reluctant to show any significant change due to the introduction of the sludge.On the other hand,the leaching toxicity of Cu in the fly ash has been found slightly increased by over 20％ whereas the contents of Ni,Pb,Hg,Cr reveal a fluctuating decrease trend.Therefore,we have found that the leaching toxicity of such heavy metal contents in the slag has been fluctuating,which may probably suggest the anisotropism of the municipal solid wastes.Besides,the entire dioxin concentration rate shows a negative correlation with the sludge mass ratio.At the same time,the total dioxin concentration in the residues has been found positively related to the Cl concentration,though negatively correlated with the S content rate in the material input,which suggests that the sludge can constructively become the inhibiting factors of the dioxin generation,whereas the introduction of sludge into the waste may not have any significant effect on the distribution of the dioxin monomers.Therefore,it can be concluded that it wouldn't be possible for the municipal solid waste incineration power plant to increase the pollutant emission in the incineration residue rate if the co-combustible factor can be kept less than 15％ of the sludge increase.