Recharge and contamination sources of shallow and deep groundwater of pleistocene aquifer in El-Sadat industrial city: isotope and hydrochemical approaches |
| |
| Authors: | M A Ahmed S G Abdel Samie H M El-Maghrabi |
| |
| Institution: | (1) National Center for Nuclear Safety and Radiation Control, AEA, Cairo, Egypt;(2) Petroleum Research Institute, Cairo, Egypt |
| |
| Abstract: | Hydrochemical and isotopic researches were conducted in El-Sadat City groundwater system to identify groundwater alteration,
recharge, residence time and extent of pollution. The groundwater salinity gradually increases as the groundwater moves from
northeastern to southwestern parts of the city. Groundwater generally shows mineralization decreasing with depth, indicating
that the possibility of recent water penetration far below the surface is limited. Shallow groundwater has an elevated level
of nitrate, which is attributed to anthropogenic sources due to intensive agricultural activity. The limit of high nitrate
water may mark the maximum penetration of groundwater from the surface, which is found in depths <100 m. The northeastern
and southwestern industrial areas are highly contaminated by some heavy metals, which may originate from some local industrial
effluents. The sewage oxidation ponds seem to show no effect on groundwater; hence, these ponds are not a point source for
these heavy metals. Dissolved ions depict five different hydrochemical facies, and stable isotopes define the recharge mechanisms,
the origin of groundwater and the hydraulic confinement of deep groundwater. The deep groundwater is untritiated and has long
residence times (in the order of thousands of years). Three different hydrochemical groups have been recognized and mapped
in El-Sadat City, based on the chemical and isotopic information of the groundwater. These groups have different levels of
contamination. The deep groundwater samples are significantly less impacted by surface activities and it appears that these
important water resources have very low recharge rates and would, therefore, be severely impacted by overabstraction. The
extensive exploitation of groundwater for drinking water supply would shortly be reflected by a gradual decline of the groundwater
table in El-Sadat City. Amelioration of groundwater quality requires further management strategies and efforts in the forthcoming
years. |
| |
| Keywords: | |
| 本文献已被 SpringerLink 等数据库收录！ |
|
