Informations et ressources scientifiques
sur le développement des zones arides et semi-arides

Titre : GROUND WATER POLLUTION IN THE KUFRA CITY - LIBYA

Auteur : Saeed, Hafed Saeed Saleh.

Etablissement de soutenance : Ain Shams University

Grade : Master Degree in Environmental Sciences 2022

Résumé partiel
The city of Kufra is located at the southeastern part of Libya, between latitudes 24°11”N and longitudes 23°17ˊE. An arid desert region, where groundwater is the main and only source in the region, and there is no other source of water. The city of Kufra was chosen for this study, due to the importance of groundwater in the region. The lack of sanitation networks and wastewater treatment plants, and the reliance on wastewater disposal in space and near residential neighborhoods and drinking water wells, and the lack of hydrological and environmental studies in general. The study relies on comparing the results of the analysis of samples of drinking water wells in the study area, with the specifications of the World Health Organization and the Libyan standard specifications. Seventeen groundwater samples were collected from the Drinking water wells in the city of Kufra. The collected samples were subjected to different analyses, in order to conduct hydro-chemical and bacteriological studies of the study area. The available groundwater water resources quality is assessed, their suitability for different uses are defined, especially the drinking water. The work was carried out by locating each well by GPS, coding and measuring water levels, and measurements for all wells. Samples were taken in different periods in three stages, the first in March, the second in June and the third in November of 2016. The physico-chemical parameters of the studied groundwater samples revealed that the groundwater of Kufra city are suitable, where the pH ranges from 6.1 to 7.04. The recorded temperatures of the studied groundwater of Kufra city samples are fluctuated from 25 to 30°C. The total dissolved salts (TDS) range from 160 to 1936 mg/L. Most of the studied groundwater samples have electrical conductivity (EC) values ranging from 250 to 3025 μS/cm. from the previous discussion, the physical and chemical parameters of the studied groundwater samples showed that, the groundwater of the city of Kufra is basically acidic to neutral, and the brackish nature to the water is basically fresh and conforms to the specifications except in well No. (14), in which the dissolved salts percentage exceeded the standard specifications of the World Health Organization and the Libyan. The analysis of positive ions (sodium, potassium, calcium and magnesium) shows that, some wells have high percentages of these parameters above the permissible ratios, according to the WHO standards and the Libyan standard specifications. While analyzing the negative ions (chlorine, sulphates, bicarbonate and nitrates) showed exceeding the permissible percentages in some wells. The bacterial tests in the study area indicate that, the fecal coliform bacteria per 100 ml/L is confined between 1 and 4 colony, forming units per 100 ml. Hydrochemistry results in the study area showed that, 23.5% of water is strong chloride, while 64.70% is average chloride and 11.76% is low chloride. It was classified as 100% carbonate water and 47% high sulfate water and 41% sulfate water. The groundwater in the Kufra basin was evaluated for various uses, including irrigation, and classified in terms of important properties, such as electrical conductivity (EC), total dissolved salts (TDS), residual sodium percentage (RSC) and magnesium adsorption rate (MAR).

Présentation étendue (EULC)