珠江三角洲地区地下水锰的分布特征及其成因

Origin and distribution characteristics of manganese in groundwater of the Zhujiang River Delta

为了解珠江三角洲地区地下水中锰的含量及其成因,笔者采集并分析了352组地下水样和13组地表水样。结果表明:珠江三角洲地区地下水的锰含量在未检出至8.32mg/L之间,平均浓度为0.34mg/L,超标率达49.4%。在该区9个地级市范围都存在地下水锰超标现象。区内地下水的锰含量与总溶解固体(TDS)、化学需氧量(COD)以及HCO3ˉ都呈极显著的正相关关系,而与Eh呈极显著的负相关关系。珠江三角洲地区地下水中锰含量的分布与该地区的工业化程度以及所处的补、径、排条件密切相关。影响该地区地下水锰含量分布的因素主要有氧化还原环境、酸碱条件、地下水的总溶解固体、上覆盖层性质、地下水径流条件以及含水层介质等。

In order to detect the origin and content of manganese in groundwater of the Zhujiang River Delta, the authors sampled and analyzed 352 groundwater samples and 13 surface water samples. The results show that manganese content varies from the undetected level to 8.32 mg/L in groundwater of the Zhujiang River Delta, with the average manganese content being 0.34 mg/L and the standard-exceeding rate being 49.4%. The manganese content of groundwater that exceeds the standard exists in nine cities of the Zhujiang River Delta. There exists an obvious positive correlation between the manganese content and TDS, COD, and HCO3 of groundwater as well as a notable negative correlation between the manganese content and Eh of groundwater in this delta area. The distribution of manganese in groundwater is closely related to the extent of industrialization and recharge, runoff and discharge conditions of this area. Redox environment, pH condition, total dissolved solids in groundwater, property of the cover, groundwater flow conditions, and aquifer media are major factors responsible for the distribution of manganese in groundwater of the Zhujiang River Delta.