东营市挑河和神仙沟的河水重金属污染评价

为评价东营市挑河、神仙沟河水中重金属的时空分布、产生生物毒性的可能性及其综合污染水平,在夏季和秋季分别采集6个河水样品,监测7种重金属质量浓度。与国内外其他河流相比,研究区域河水中重金属(除Cd、Pb外)质量浓度均处于中等水平。大多数重金属在夏季质量浓度较高,且具有明显的空间分布。根据美国环保署制订的国家推荐性水质基准,各站位的Zn在两个季节均可能造成水生生物急性中毒;而大多数站位的Cu可能产生急性中毒(夏季)或慢性毒害(秋季)。改进型内梅罗指数计算结果表明,夏秋两季所有站位(除秋季1个站位外)的重金属综合污染水平达到严重等级,Hg对综合污染的贡献最大。Cu-Hg、Cu-Pb(挑河)及Cu-Pb-Cd(神仙沟)之间的显著正相关性与河流两侧分布的铜业、化工、电子、机械制造等企业的废水排放有关;河水Zn与上述元素大多呈显著负相关,其可能来源于沿河两侧路尘(含Zn)在河水中的沉降。

Assessment of heavy metal pollution in the surface water of Tiaohe River and Shenxiangou Brook,Dongying City,Shangdong

In this paper,an assessment has been made over the heavy metal pollution in the surface water of Tiaohe River and Shenxiangou Brook,Dongying City,Shandong.In it,we have identified and determined the concentrations of seven trace metals in the six water samples from the two rivers in summer and autumn(2015-08 and 2015-11) in hoping to find their spatiotemporal distribution and liability to produce the biological toxicity and the combined pollution associated with them.As a result,we have found that the mass concentration (μg/L) of Hg,As,Cu,Pb,Cd,Zn and Cr6+ are equal to ND-0.37,3.7-16.75,9.15 -14.95,0.65-4.70,0.10-0.24,106.8-205.7 and ND-4.71 in Tiaohe River,respectively,whereas ND-0.46,ND-8.6,8.2-39.2,2.00-15.50,0.05-0.32,132.8-211.6 and ND-4.20 in Shenxiangou Brook,correspondingly.As for the metal concentrations in the water samples under study,the contents except for those of Pb and Cd,can be taken as of the moderate level when compared to those observed in other rivers of the world.The contamination levels of the five metals (Hg,As,Cu,Pb and Cd) turn out to be rather high during the summer seasons,most of which also assume to reveal an obvious spatial fluctuation.On the other hand,if they are evaluated in accordance with the National Recommended Water Quality Criteria by US EPA,Zn on all the sites tends to induce acute toxicity during the both seasons,while Cu at most sites may cause acute and chronic toxicity during the summer and the autumn season,respectively.What is more,when the integrated pollution assessment is done by using the improved Nemero index method,the river waters from all the sites in the both seasons can be said heavily polluted except one site in autumn.It is also worthy to be noticed that Hg had a strong effect on the integrated pollution of the river water than the other metal contaminants.Besides,it has also been found that the significant positive correlation has been detected between Cu-Hg and Cu-Pb in Tiaohe River and Cu-Pb-Cd in Shenxiangou Brook,which should be attributed mainly to the copper-making sewage as well as the chemical engineering,electronic and mechanical manufacturing industry sewage from the nearby factories.Among them,Zn is supposed to be significantly negative-correlated with the metal contaminants mentioned above,implying that the metal contaminants are probably originated from the settling behavior of the road dust with zinc given off the river water.Furthermore,water temperature and oxidation-reduction potential (ORP) should also make an effect on the spatial distribution of the multi-metal pollutants from the rivers,though dissolved oxygen (DO) and pH may have little effect.