Hydrochemical modeling of groundwater quality from Sinai, eastern and western deserts, Egypt

Groundwater represents the main source of water in Egypt except the area of Nile valley which depends on Nile water. In this study, 23 groundwater samples from Egyptian desert areas were collected from Western Desert, Sinai and Eastern Desert (El Sebayia and Qussier). The present study focused on assessing the hydrochemistry and suitability of groundwater for drinking and irrigation purposes. For deducing the factors controlling water hydrochemistry; Piper, Gibbs and End-member diagrams were applied. The suitability of water for drinking was assessed by water quality index (WQI) model. The applied diagrams indicated that the studied samples are mainly of Ca-Mg-Cl-SO4 facies and controlled by water-rock interaction. The WQI revealed that Western and Eastern deserts groundwater samples are of poor quality for drinking while Sinai groundwater is of marginal quality. The main problem in the Eastern Desert is the salinity, As and Cd content, while in Sinai and Western Desert is heavy metals (e.g. As, Cd, Ni and Pb) surplus the drinking water guidelines. The application of diagrams and models give a good and fast visualization of the chemistry of water. The Western Desert and Sinai groundwater can be used for irrigation safely, but Eastern Desert samples have unacceptable salinity. The occurrence of organic compounds (especially petroleum derivatives) may be attributed to the black shale beds, especially in the Carboniferous Aquifer of Sinai.