河流表层沉积物活体毒性甄别和毒性因子初探

本文选择辽河流域6个支流表层沉积物作为研究对象,利用2种底栖生物(摇蚊幼虫和河蚬)活体毒性测试方法评价了辽河流域表层沉积物毒性.研究结果显示,所有表层沉积物对摇蚊幼虫有毒性效应,显著降低了摇蚊幼虫的存活率(p<0.05);河蚬存活率有所降低,但差异不显著.沉积物活体毒性甄别结果发现,长沟子以有机物污染为主,付家窝堡和柴河以重金属污染为主,一统河和潮沟河以有机物和氨氮污染为主,而柳河以重金属和氨氮污染为主.综上所述,沉积物活体毒性甄别方法能有效甄别致毒污染物类别,同时表明不同种类底栖生物对沉积物毒性存在敏感性差异.

Exploration of toxicity factor and in vivo toxicity identification evaluation of surface sediments

The toxicity of surface sediments from 6 branches of Liaohe River was investigated using in vivo toxicity test. The tests were survival tests with two benthic invertebrates included midge (Chironomus riparius) larva and Asian freshwater clam (Corbicula fluminea). The results showed that all survival rates of midge larva exposed to surface sediments were significantly decreased compared to the controls (p<0.05), but not in Asian freshwater clam. Results of toxicity identification and evaluation in vivo showed that the main toxicity factors of Changgouzi River, Fujiawobao River and Chai River were organic pollutants and heavy metals, respectively. Moreover, the main toxicity factors of Yitong River and Chaogou River were organic pollutants and ammonia, whereas those of Liu River were heavy metals and ammonia. In summary, it is feasible to identify toxicity factors using toxicity identification and evaluation in vivo. Additionally, the results demonstrate differences in the sensitivities of species to sediment toxicities.