Faculty of Geoscience and Environmental Engineering, Southwest Jiaotong University, Chengdu 611756, China.
College of Water and Environmental Engineering, Sudan University of Science and Technology, Khartoum 12304, Sudan.
Int J Environ Res Public Health. 2020 Feb 14;17(4):1245. doi: 10.3390/ijerph17041245.
The present study proposes a new approach for indexing heavy metals ions to examine groundwater quality in North Kurdufan Province, Sudan. The new approach is developed based on the most frequently used methods for indexing heavy metals pollution in water. It is created in order to avoid the weaknesses of the current indexing systems. As per the new indexing approach, heavy metal contamination in water samples is evaluated by two types of indices: the negative evaluation index (NEI) and positive evaluation index (PEI). The water worthiness is assessed based on a pair of indices, NEI and PEI. Water quality increases with the decrease of PEI and NEI values. NEI indicates the contribution of heavy metals with a concentration not exceeding the highest desirable limit (I i ) in the water sample, while vice versa regarding the PEI. If all heavy metals concentrations in the water sample do not exceed I i , the sum of NEI should be less than zero, but not less than -100, implying that the sum of PEI will be zero. When all heavy metals concentration exceeds I i , the sum of NEI should be equal to zero, and PEI will be greater than zero. The results of the newly proposed approach have been discussed and compared with the existing indexing methods as regards to the best and worst samples. The spatial distribution of NEI and PEI are in complete agreement with the metals spatial distribution. The comparison result showed that the new index is robust, with fair calculations, and gives the best classification of groundwater quality.
本研究提出了一种新的方法，用于指示重金属离子，以检查苏丹北科尔多凡省的地下水水质。该新方法是基于最常用于指示水中重金属污染的方法开发的。它是为了避免当前索引系统的弱点而创建的。根据新的索引方法，水样中的重金属污染通过两种类型的指数进行评估：负评估指数（NEI）和正评估指数（PEI）。水样的可利用性是基于一对指数，即 NEI 和 PEI 来评估的。随着 PEI 和 NEI 值的降低，水质会提高。NEI 表示水样中浓度不超过最高理想限值（I i ）的重金属的贡献，而 PEI 则相反。如果水样中所有重金属浓度均不超过 I i ，则 NEI 的总和应小于零，但不小于-100，这意味着 PEI 的总和将为零。当水样中所有重金属浓度均超过 I i 时，NEI 的总和应为零，PEI 将大于零。已经讨论了新提出的方法的结果，并与现有的索引方法就最佳和最差样本进行了比较。NEI 和 PEI 的空间分布与金属的空间分布完全一致。比较结果表明，新指数具有稳健性，计算合理，并能对地下水质量进行最佳分类。
