城市污水处理厂中NP_nEO的迁移转化

Transport and behavior of nonylphenol ethoxylates in a full-scale municipal wastewater treatment plant

为研究短链壬基酚聚氧乙烯醚(NPnEO,n=1,2)在城市污水处理A/O工艺中的迁移转化行为,采用固相萃取-气相色谱-质谱(SPE-GC-MS)方法测定东北某城市污水处理厂A/O工艺中短链NPnEO(n=1,2)及其代谢产物(NP)在各处理单元水相和污泥相中的含量及分布.污水处理全流程样品分析发现:进水中NP1,2EO的质量浓度较低,NP、NP1EO和NP2EO的平均质量浓度分别为1 973、1 784和891 ng/L;流经曝气沉砂池后3种物质质量浓度可达3 326、4 228和2 066 ng/L,显著高于进水中目标化合物的质量浓度水平;经厌氧池污泥的吸附作用后,NP1EO、NP2EO和NP含量显著降低;二沉池出水中质量浓度分别为351、328和159 ng/L.结果表明:厌氧段对水相中NPnEO的去除贡献较大;各处理阶段中NP1EO、NP2EO和NP的质量浓度与TOC质量浓度呈正相关.

To study the transport and behaviour of short chain nonylphenol ethoxylates（NPnEO,n=1,2） in anoxic/oxic（A/O） process of municipal wastewater treatment plant,the distribution of short chain NPnEO and NP in the aqueous phase and sludge of each unit process in a full-scale municipal wastewater treatment plant of northeast China were investigated using a solid phase extraction-gas chromatography-mass spectrometry（SPE-GC-MS）.The results showed that the influent NP,NP1EO and NP2EO were 1 973,1 784 and 891 ng/L,which were lower than those of other cities in China and many other countries,then the concentrations of three compounds increased and reached to the highest at aeration grit chamber due to the biodegradation of long chain NPnEO,which were 3 326,4 228 and 2 066 ng/L,respectively,after that the concentrations of them were dropping down significantly at anaerobic sink because of the adsorption of activated sludge,and finally the effluent NP,NP1EO and NP2EO were 351,328 and 159 ng/L.It is concluded that the anaerobic sink made more contribution for the removal of these compounds in influent.In addition,the concentrations of NP,NP1EO and NP2EO in each treatment unit have a positive correlation with their TOC content.