摘要
通过对典型煤矿区的河流表层沉积物进行调查与采样分析,探讨不同类型河流沉积物重金属质量比的变化及对水生态环境的影响。结果表明,受矸石堆场排水、矿井排水和洗煤排水的影响,煤矿区污染河流的沉积物可分为砂质沉积物、黄色泥质沉积物和黑色泥质沉积物。黄色泥质沉积物中Fe、Cd、Hg的平均质量比分别是黑色泥质沉积物的4.46倍、2.19倍、1.59倍,是砂质沉积物的2.36倍、2.43倍、1.59倍;而黄色泥质沉积物中Cr的平均质量比分别是黑色泥质沉积物和砂质沉积物的1.20倍和8.5%;黄色泥质沉积物中Pb、As的平均质量比分别是黑色泥质沉积物的22.62%和45.85%,是砂质沉积物的47.21%和88.84%。3种沉积物之间Fe和Pb的平均质量比差异较大,其次为Cd和As,再次为Hg、Zn、Mn。通过对沉积物重金属进行潜在生态风险指数(RI)分析、覆水释放与隆线溞生物毒性试验,发现3种沉积物重金属都具有很强的生态风险,其强度从大到小表现为黄色泥质沉积物、黑色泥质沉积物、砂质沉积物。
This paper is committed to an investigation on the river sediments in 2 typical coal mining areas based on their local source features by collecting 24 kinds of authentic samples.For the study purpose,we have done the latent ecological risk assessment for the heavy metal contents in different types of sediments with the so-called Hakanson potential ecological risk index.At the same time,we have also carried out the overlying water soaking test on the collected sediment samples in the laboratory,and then Daphnia carinata biological toxic test has been done by the overlying water obtained by soaking the sediments.The results of our investigation have shown that under the impact of the gangue dumps drainage,the mining drainage and the coal washing drainage,it is possible for us researchers to divide the aforementioned sediments into three sorts：the sandy sediments（SS）,the yellow argillaceous sediments（YAS） and the black argillaceous sediments（BAS）,by which we have found that the contents of the heavy metal can be listed as follows：the rates for Fe,Cd or Hg in the YAS are 4.46 times,2.19 times or 1.59 times of that in the BAS,respectively,whereas 2.36 times,2.43 times or 1.59 times of that in the SS.As to the content of Cr in the YAS,it accounts for 1.20 times of that in the BAS,and 85%of that in SS.In addition,the contents of Pb and As in the YAS are 22.62%and 45.85%of those in the BAS,and 47.21%and 88.84%of those in the SS respectively.The contents of Pb and Fe in the three sediments have the largest deviations,followed by Cd and As,then Hg,Zn and Mn.The results of Hakanson potential ecological risk assessment demonstrate that the potential ecological risk indexes（RI） of heavy metals in the three kinds of sediments in the study area have all reached the ＂ very strong＂ level On average,the RI value of the YAS may account for 1.67 times of that in the BAS,while 1.79 times of that in SS.Fe,Mn,Hg and As are the major exceeded elements in overlying water of the three kinds of sediments.The concentrations of Fe and Mn in the overlying water of YAS are equal to 1.83 times and 1.41 times of those in SS overlying water respectively,and 98.90 times and8.20 times of those in overlying water of BAS,respectively.Besides,the concentrations of Hg and As in the overlying water of BAS stand for 5.74 times and 116.91 times of those in YAS overlying water respectively,and 10.03 times and 131.06 times of those in SS overlying water.The overlying water of the three kinds of sediments have all exhibited strong toxicity towards Daphnia carinata,and its toxicity intensity generally manifests in a descending order as is shown below：YAS 〉BAS〉 SS.
出处
《安全与环境学报》
CAS
CSCD
北大核心
2017年第1期364-370,共7页
Journal of Safety and Environment
基金
国家自然科学基金项目(41661094)
贵州省联合基金项目(黔科合丁字LKN[2013]27号)
关键词
环境科学技术基础学科
煤矿区
河流沉积物
重金属
生态风险评价
basic disciplines of environmental science and technology
coal mining area
river sediment
heavy metal
ecological risk assessment
