江苏省城市污泥中多环芳烃的含量及其主要影响因素分析

采用高效液相色谱,对江苏省21家代表性城市污水处理厂污水污泥中多环芳烃含量进行了分析.结果发现,污泥中含有7-16种PAH化合物,都是以2(或3)个苯环的化合物为主,而难降解4-6个苯环的化合物所占质量分数均较低.但污水来源及其处理方式、污泥处理方法等均影响着污泥中PAHs的含量及组成,消化可明显降低污泥中PAHs的含量.污泥中∑PAHs总量在11.68-169.91 mg·kg-1,各污泥间含量差异显著;具有致癌性的PAHs含量在1.17-41.03 mg·kg-1,平均值为6.59mg·kg-1;被列入中国环境"优先污染物"的PAHs含量在4.07-59.06 mg-kg-1之间.其中萘是江苏城市污泥中均含有的PAHs化合物,而对于强致癌性化合物苯并(a)芘,其含量相对较低,在污泥中含量一般在0-2.20 mg·kg-1,平均含量为0.15mg·kg-1,远低于我国农用污泥控制标准的3.0 mg·kg-1.

Content and Its Major Influencing Factors of Polycyclic Aromatic Hydrocarbons (PAHs) in Municipal Sewage Sludge of Jiangsu Province

Sewage sludge from 21 representative sewage treatment plants of Jiangsu Provice were measured for polycyclic aromatic hydrocarbons (PAHs) using HPLC. Results showed that PAHs were widely distributed in municipal sewage sludges. Total amount of PAHs (sigma PAHs, 16 PAHs in the priority contaminants of US EPA )ranged from 11.68 mg x kg(-1) to 169.91 mg x kg(-1), depending on sludge origins. Total concentration of carcinogenic PAHs was 1.17 mg x kg(-1) to 41.03 mg x kg(-1) with an average value of 6.59 mg x kg(-1). Total amount of PAHs classified as a priority contaminants in the light of regulations of EPA China was from 4.07 mg x kg(-1) to 59.06 mg x kg(-1). PAH Compounds with two or three benzene rings were dominant among the 7-16 PAHs found in the sludge, while the percentage of compounds containing four to six benzene rings was low. Naphthalin was the main PAHs' compounds in the selected municipal sludg. The concentration of BaP, a strong carcinogenic PAH, was found in sludge with 0-2.20 mg x kg(-1) and the average of 0.15 mg x kg(-1), which was much less than 3.0 mg x kg(-1) of the control standard of sludge land application. Furthermore, it was also noted that wastewater types, sewage treatment techniques, and anaerobically sludge digestion had great effects on PAHs contents in sludge.