Application of water quality index and statistical-hydrochemical techniques in groundwater assessment of the Quaternary aquifer, southwest Nile Delta of Egypt

Abstract

The objective of the current study is to investigate the hydrogeochemistry of the Quaternary groundwater and evaluating its suitability for drinking and irrigation needs using statistical analysis, water quality indicators and physicochemical parameters, in west of the Nile Delta, Egypt. The study area has high population growth and agricultural activities, which require groundwater protection, and predicting probable environmental problems. For these reasons, 54 groundwater samples were collected during April 2021. Hierarchical cluster analysis, Pearson, and factor analysis used for statistical analysis. Biplots, Gibbs and Piper diagrams were used to infer the geochemical processes controlling groundwater chemistry. The groundwater is affected by silicate weathering, reveres ion exchange, dissolution of CO2, and recharge from the Nile. According to the WQICCME drinking value, the groundwater ranged between fair to marginal water quality. The distribution of integrated-weight water quality index of the samples, showed that it is excellent for irrigation (< 25). The nine physicochemical parameters sodium percent (Na%), permeability index, sodium adsorption ratio, Kelley Index, residual sodium carbonate, magnesium hazard, Potential Salinity, Corrosive Ratio and Chloro-alkaline Indices revealed that most of the groundwater are of good quality and can be safely used for agricultural activities, albeit few samples due the west needs some treatment. It is recommended to minimize the fertilizers and nutrients use to decrease the anthropogenic impact on the groundwater. The reuse of irrigation water without treatment should be limited. As well, the pumping rates should be controlled to avoid aquifer salinization.