Abstract

Groundwater samples from five rural agricultural villages within the Anambra basin of southeastern Nigeria were selected for the determination of their drinking quality, hydrogeochemical characteristics, corrosivity and scaling potentials. The groundwater temperature ranged from 10 to 31 °C. The pH measurements revealed that the samples are acidic. Parameters such as total dissolved solids, electrical conductivity, magnesium, calcium, sodium, chloride, bicarbonate, sulfate and nitrate recorded scores within their respective standard limits. However, potassium and phosphate pollution was observed in some samples. Synthetic pollution index was used to summarize the drinking water quality of the samples. The results showed that 88% of the samples were moderately polluted while 12% were highly polluted. Thus, the results show that they have questionable drinking water quality. Several indices used for corrosivity and scaling analyses indicated that, although the samples pose low risk of scaling (encrustation), they are severely aggressive. Hence, they are likely to deteriorate metallic water storage and distribution facilities in the study area. The predominant water facies are Cl·SO₄–Ca·Mg and Cl·SO₄–Na·K. Multiple hydrogeochemical and chemometric analytical models were integrated to better unravel and understand the geochemical history, processes and evolution of the groundwater. All of the models used jointly indicated that mixed, multiple processes, namely mineral-rock weathering, ionic exchange processes and anthropogenic inputs, are responsible for the predominant hydrogeochemistry observed in the study area. However, in this regard, natural, geogenic processes were identified as more important factors than those from anthropogenic activities.

摘要

选择了尼日利亚东南部阿南布拉盆地五个农村的地下水样本，以确定其饮用质量、水文地球化学特征、腐蚀性和结垢潜力。地下水温度范围为 10 至 31 °C。pH 测量表明样品是酸性的。总溶解固体、电导率、镁、钙、钠、氯化物、碳酸氢盐、硫酸盐和硝酸盐等参数在各自的标准限值内记录得分。然而，在一些样品中观察到钾和磷酸盐污染。综合污染指数用于总结样品的饮用水质量。结果显示，88%的样本为中度污染，12%为高度污染。因此，结果表明，他们的饮用水质量有问题。用于腐蚀性和结垢分析的几个指标表明，尽管样品的结垢（结壳）风险较低，但它们具有严重的腐蚀性。因此，它们很可能会破坏研究区的金属水储存和分配设施。主要水相为 Cl·SO₄ –Ca·Mg 和 Cl·SO ₄ -Na·K。整合了多种水文地球化学和化学计量分析模型，以更好地揭示和了解地下水的地球化学历史、过程和演化。联合使用的所有模型表明，混合的多个过程，即矿物-岩石风化、离子交换过程和人为输入，是研究区观察到的主要水文地球化学的原因。然而，在这方面，自然地质过程被确定为比人为活动更重要的因素。