城市回用水致突变性研究

Study on Mutagenic Effect of Reclaimed Water in Tianjin

目的对城市回用水的致突变性进行分析。方法于2005年9月(丰水期)和2006年4月(枯水期)采集处理前、后的城市回用水水样,利用固相萃取和气相色谱-质谱联用(GC-MS)技术测定城市回用水中16种多环芳烃(PAHs)的含量。采用Ames试验检测其致突变性,设2000、1000、500、250ml/皿(相当于原水的体积)4个剂量组,以及溶剂对照组和阳性对照组[敌克松(50μg/皿)]。结果丰水期和枯水期两次水样中均检测出PAHs,主要为芴和菲,其次为萘、苊、二氢苊、蒽、荧蒽、芘等。丰水期进水水样中16种PAHs的总浓度为1777.9ng/L,出水水样为1380.1ng/L;枯水期进水水样中16种PAHs的总浓度为2225.1ng/L,出水水样为1827.1ng/L。在无代谢活化系统条件下,丰水期进水水样对TA98菌株在2000ml/皿及TA100菌株在1000ml/皿时;出水水样对TA98在250ml/皿时,TA100菌株在500ml/皿时,回变菌落数均超过溶剂对照组1倍以上,且具有剂量-反应关系。枯水期进、出水样对TA98、TA100菌株在250ml/皿时,回变菌落数均超过溶剂对照组1倍以上,且具有剂量-反应关系。水样在2000ml/皿时,不同程度地出现抑菌现象。结论城市回用水含有一定量的PAHs,Ames试验表明城市回用水处理后并未完全去除有机污染物,仍具有致突变作用。

Objective To study the mutagenic effect of reclaimed water in Tianjin. Methods Reverse phase C-18 solidphase extraction （RP-C18SPE） was used for the extraction of target compounds from water samples. Ames test was used to detect mutation. Results PAHs were detected in both low-water and high-water period,including fluorene, phenanthrene, naphthalene, acenaphthylene and acenaphthene. In the high-water period, the total concentration of 16 kinds of PAHs was 1 777.9 ng/L and 1 380.1 ng/L in untreated reclaimed water and treated reclaimed water respectively, in the low-water period,it was 2 225.1 ng/L and 1 827.1 ng/L respectively. Ames test showed that both untreated reclaimed water and treated reclaimed water could induce mutation of TA98 and TA100 strains with a dose-response relationship. Conclusion The reclaimed water used in Tianjin still contains PAHs of a certain level, which have mutagenic effect.