电镀污泥焚烧过程中的热分析以及重金属的迁移规律

选取一种典型的含重金属危险废弃物电镀污泥,研究了电镀污泥的热特性以及不同重金属元素———铅(Pb)、镉(Cd)、铜(Cu)、锌(Zn)、镍(Ni)和锰(Mn)在焚烧产物中的迁移和排放特征.热重分析结果表明,干电镀污泥热重的升温过程中主要有几个失重高峰:100℃,150℃和600℃,其中100℃和150℃主要是电镀污泥中的挥发酚的析出,以及一些有机物质的热解和焚烧,而600℃主要是碳酸盐分解的结果;从能谱分析可知电镀污泥主要由O,S,Al,Ca,Cr,Fe等元素,还有一些次要元素如Mg,Cu,Zn,P,Cl,C组成.升温过程中,非金属元素C和Cl有较为明显的下降,Cr,Fe,Mg在900℃以内变化不大.从迁移规律实验可知,重金属Mn、Pb、Ni和Cu在焚烧过程中随着温度升高含量逐渐降低,其中又以Ni的含量下降最为明显,而Cd则正好相反有明显的富集效应.

Thermal Analysis and the Distribution Rule of Heavy Metals During Electroplating Sludge Combustion

A representative hazardous waste containing heavy metal is electroplating sludge, Thermal characteristic and the distribution of different heavy metal elements (Pb, Cd, Cu, Zn, Ni and Mn) was studied. The results of experiment show that from thermal analysis, in the process of experiment of thermal gravity there are some peaks of weight loss as 100 degrees C, 150 degrees C and 600 degrees C among these peaks, the peaks of 100 degrees C and 150 degrees C is caused by that the volatile separated out and organic matter combusted and pyrolysed at the same time, the peak of 600 degrees C is produced by the carbonate decomposed. From EDS analysis, electroplating sludge is composed by these main elements which are O, S, Al, Ca, Cr and Fe, and other secondary elements such as Mg, Cu, Zn, P, Cl and C. In the process of temperature promoted, the quantity of nonmetal such as C and Cl is decreased, and the quantity of Cr, Fe, and Mg is steady within 900 degrees C. From the experiment of distribution rule, the quantity of Mn, Pb, Ni and Cu decreased in the process of combustion while the furnace temperature raised,among these heavy metal the quantity of Ni decrease most obviously,and on the contrary the quantity of Cd enrich obviously in this process.