山东某污水处理厂中环型和线型甲基硅氧烷的行为归趋

Occurrence and fate of cyclic and linear methylsiloxanes in a wastewater treatment plant in Shandong Province,China

本文研究了山东某污水处理厂污水及污泥中3种环型甲基硅氧烷(D4—D6,CMS)和12种线型甲基硅氧烷(L5—L16,LMS)的行为归趋.进水中总甲基硅氧烷(∑MS)的浓度为15.7—65.7μg·L^(-1)(平均值:39.2μg·L^(-1)),其中∑LMS占比为98. 2%.进水中∑MS浓度夏季最高(65. 7μg·L^(-1)),其次分别是秋季(41.7μg·L^(-1))、冬季(33.7μg·L^(-1))和春季(15.7μg·L^(-1)).出水中∑MS浓度为6.24—14.3μg·L^(-1)(平均值:10.6μg·L^(-1)),平均去除率为73.0%.污泥中∑MS的浓度为14.1—48.4μg·g^(-1)(平均值:20.3μg·g^(-1)),D4—D6的泥水分配系数(lg Kd)为3.84—4.44,L6—L16的lg Kd为2.24—4.30.此外,通过计算甲基硅氧烷的危险商数(hazard quotients,HQ)评估了其对水生生物的危害,发现污水处理厂出水中目标化合物的潜在危害较低.

Occurrence and fate of three cyclic( D4—D6,CMS) and twelve linear( L5—L16,LMS)methylsiloxanes in the wastewater and sludge collected from a wastewater treatment plant( WWTP)in Shandong Province were studied. The concentrations of total methylsiloxanes( ∑ MS) in the influent were 15. 7—65. 7 μg·L-1( Mean: 39. 2 μg·L-1),and ∑ LMS were the predominant( 98.2%). Influent samples collected during the summer contained the highest ∑MS concentrations( 65.7 μg·L-1),followed by autumn( 41. 7 μg·L-1),winter( 33. 7 μg·L-1) and spring( 15.7 μg·L-1). ∑ MS concentrations in the effluent were 6. 24—14. 3 μg · L-1( Mean:10.6 μg·L-1),with 73. 0% average removal efficiency. The ∑ MS concentrations in the sludge ranged from 14. 1 to 48. 4 μg·g-1( Mean: 20. 3 μg·g-1). The logarithm values of solid—liquid distribution coefficients of D4—D6 and L6—L16 were 3.84—4.44 and 2.24—4.30,respectively. In addition,the hazard quotients( HQ) of siloxanes were used to evaluate their ecological risk to aquatic organisms,results suggested that the target compounds in the effluent would pose little potential adverse ecological risk.