广西红水河中下游马山地区地下水重金属含量及分布特征

Characteristics of the content and distribution of heavy metals in groundwater in Mashan area,middle to lower Hongshui River,Guangxi,China

为了解红水河中下游马山地区地下水重金属含量及分布特征,以西南岩溶地下水污染调查评价中广西红水河中下游马山地区地下水数据为基础,对该地区27件样品的重金属含量特征、重金属间相关关系、重金属与其它化学组分的相关性以及地下水重金属分布特征进行了研究。结果表明:研究区地下水中重金属含量整体偏低,平均质量浓度顺序为Fe>(Al)>Zn>Mn>Pb>Se>As>Cd,重金属平均质量浓度均小于中国生活饮用水标准值,且绝大部分重金属含量远远低于该标准值。Mn与Fe、As、Al存在显著或极显著的正相关关系,Zn与Pb、Cd存在明显的相关性,Se与其它7种重金属的相关性均不明显,可能是由于Se与其它重金属的来源差异较大所致。地下水的酸碱性对重金属的富集影响较小,但地下水中主化学成分HCO-3和Ca2+对重金属的富集有较大影响,TDS对绝大部分重金属的影响较小,对As和Cd具有一定的影响。地下水中Mn、Zn、As、Pb、Cd、Se、Al、Fe质量浓度在空间上表现出一定的地区分布特点,整体上重金属高浓度点主要集中在马山县城周围以及古寨、乔利街乡镇周围。

Based on the groundwater data obtained from the karst groundwater and information gained from the groundwater pollution investigation and evaluation in the southwest China, this work analyzes geochemical characteristics of 10 heavy metals with 27 karst groundwater samples collected in Mashan area located in the middle to lower Honghe River. The main focus of this study is to establish a relationship between the concentrations of heavy metals and their spatial distribution and the other chemical constituents dissolved in the karst groundwater, as well as the relationship between the heavy metals studied. The results indicate that the concentration of heavy metals is lower than the upper limit for drinking water standard of China, and the contents of heavy metals in the groundwater follows a descending order as Fe〉Al〉Zn〉Mn2〉Pb〉Se〉 As〉Cd. There is a remarkably positive correlation between Mn, Fe, As and A1, and a significant positive correlation between Zn and Pb, Cd in the groundwater as well. The relationship between Se and other seven heavy metals is not that apparent, perhaps due to the diversity of the heavy metal sources. All the heavy elements have no correlation with pH, whereas the chemical contents HCO3- , Ca2＋ and HCO2 have a great impact on the heavy metal concentrations. TDS has little effect on most of the heavy metals, but a certain effect on the appearance of As and Cd. In terms of spatial distribution of the heavy metals, the localities with high concentrations mainly occur in and around the city Mashan and townships in the vicinity of Guzhai and Qiaolijie.