Department of Earth Science, Sapienza University, Piazzale Aldo Moro 5, 00185, Rome, Italy.
Department of Environmental Biology, Sapienza University, Piazzale Aldo Moro 5, 00185, Rome, Italy.
Environ Sci Pollut Res Int. 2019 Jan;26(1):62-77. doi: 10.1007/s11356-018-3474-0. Epub 2018 Oct 24.
Many areas in the Southern African Development Community are data-poor and poorly accessible. Water quality assessment in these areas therefore has to rely on the limited available data, coupled with restricted field sampling. This paper documents the first evaluation of the main geochemical processes and impact of anthropogenic and natural sources of contamination on the groundwater quality of the aquifer system used for domestic and agricultural purposes in Limpopo National Park, Gaza Province, Southern Mozambique. Twenty-five groundwater and surface water samples were collected during two field campaigns, one in October 2016 (the end of the arid period) and the other in March 2017 (the end of the wet period). In the field, the researchers analysed chemical-physical parameters such as temperature, pH and EC. In the laboratory, the major ions (boron, Na, Ca, K, Mg) and anions (Cl, SO, NO, HCO, CO) were determined, and almost all groundwater samples fall into the brackish water category. The B/Cl ratio and δB concentrations were then measured to better understand the origin of these brackish waters. The direct relationship between boron and chlorine and δB concentrations above 40‰ suggests the presence of fossil water in the aquifer. The groundwater in this area was found to be above the limits stated as desirable by the Department of Water and Sanitation (DWS) and the World Health Organisation for domestic and irrigation purposes. The suitability of the groundwater for drinking purposes was also evaluated, with the results indicating that it is not suitable. The values of the sodium absorption ratio, sodium percentage and electrical conductivity show that most of the groundwater samples are also not suitable for agricultural purposes. However, the surface waters have higher quality for both domestic and irrigation purposes. The water of Massingir Lake turns out to be the most suitable resource for a possible rural development plan for the area.
南非发展共同体的许多地区数据匮乏，难以获取。因此，这些地区的水质评估必须依赖有限的可用数据，并结合有限的实地采样。本文记录了首次评估主要地球化学过程以及人为和自然污染源对用于林波波省、加扎省、莫桑比克南部的莱博洛国家公园国内和农业目的的含水层系统地下水质量的影响。在两次实地考察中收集了 25 个地下水和地表水样本，一次是在 2016 年 10 月（干旱期结束），另一次是在 2017 年 3 月（湿润期结束）。在野外，研究人员分析了化学物理参数，如温度、pH 值和 EC 值。在实验室，测定了主要离子（硼、钠、钙、钾、镁）和阴离子（氯、硫、硝、碳酸氢根、碳酸根），几乎所有的地下水样本都属于微咸水类别。然后测量硼/氯比值和 δB 浓度，以更好地了解这些微咸水的来源。硼和氯之间的直接关系以及 δB 浓度高于 40‰表明含水层中存在古水。该地区的地下水被发现超过了南非水务和卫生部 (DWS) 和世界卫生组织规定的国内和灌溉用途的理想限值。还评估了地下水用于饮用水的适宜性，结果表明它不适宜。钠离子吸收率、钠百分比和电导率的值表明，大多数地下水样本也不适用于农业用途。然而，地表水在国内和灌溉方面的水质更高。马辛吉尔湖的水对于该地区可能的农村发展计划来说是最合适的资源。
