多环芳烃类有机污染土作为水泥生料的热解析实验

THERMAL DESORPTION EXPERIMENT OF POLYCYCLIC AROMATIC HYDROCARBONS CONTAMINATED SOIL USED AS CEMENT RAW MEAL

采集首钢焦化车间周边土壤,分别进行了TG曲线、素土热处理及生料热处理实验,结果表明:所取土壤中含有多种PAHs类有机污染物,多环芳烃总含量约156.39 mg/kg。PAHs污染土在低于850℃条件下,失重可分为失水、有机物分解及无机碳酸盐分解三个阶段。随着加热温度的增加,素土中的总PAHs去除率升高。将污染土替代水泥硅质原料配制水泥生料,经300℃处理,污染土中PAHs除了萘、苊、二氢苊及蒽外,其他有机物均有残留,说明水泥生料对污染物有一定的吸附作用。600℃处理后,除少量菲残留外,其余有机物基本没有残留。因此,PAHs进入水泥窑协同处置,尤其要考虑生料磨及二级悬浮预热器的烟气中污染物含量。

Taking polluted soil surrounding a Shougang coking workshop as sample object,TG analysis,and thermal analysis on raw soil and cement raw mill experiments were conducted,the results showed that: The polluted soil contained various organic pollutants of PAHs, and the total concentration of PAHs was about 156. 39 mg / kg. Weight loss of the soil contaminated by PAHs could be divided into three stages at 850 ℃ : Water losing stage,organic matter decomposition stage,and inorganic carbonate decomposition stage. With the increase of heating temperature,removal rate of total PAHs in raw soil went up. Using polluted soil as cement siliceous raw material,except naphthalene,acenaphthene,two hydrogen acenaphthene and anthracene,other organic compounds of PAHs had residues at 300 ℃ and small amounts of phenanthrene had residue at600 ℃,showing that cement raw material had certain adsorption on PAHs pollutants. Therefore,when polluted soil of PAHs was coprocessed into the cement kiln,the content of pollutants in flue gas volatilization should be focused on.