城市黑臭水体整治前后上覆水和孔隙水的生物毒性对比和评价

以常州市典型城市黑臭水体神童浜为对象,采用小球藻和大型溞作为急性毒性测试手段,对整治前、后神童浜4个点位的上覆水和孔隙水的毒性效应进行了对比和评价。结果表明,整治后神童浜上覆水水质明显改善;上覆水在整治前、后对小球藻生长均无抑制作用,反而呈促进作用;对黑臭水体的整治降低了上覆水和孔隙水的生物毒性,但整治后的上覆水仍存在富营养化问题,且孔隙水对水生生物仍具有一定的毒性风险。提出,利用生物毒性测试能反映出黑臭水体整治前、后的毒性变化,可应用于对黑臭水体整治效果的评价。

Assessment of Toxicity of Overlying Water and Interstitial Water for Urban Black and Odorous Water Before and After Remediation

The Chlorella vulgaris and Daphnia magna acute toxicity tests were employed to compare and evaluate the toxicity of the overlying water and interstitial water in an urban black and odorous water (Shentongbang in Changzhou) before and after remediation. The results indicated that the water quality was improved by the remediation. The growth rate of C. vulgaris were not inhibited by the overlying water, by contrast stimulated both before and after remediation. The results showed that the remediation of black and odorous river reduced the biological toxicity of the overlying water and interstitial water, but there was still eutrophication in the overlying water and the interstitial water also had certain toxic risk to aquatic organisms after remediation. The present research proved that the toxicity changes of black and odorous water could be reflected by biological toxicity tests, which could be used on the assessment of remediation effects on urban black and odorous water.