Hydro-geochemistry and Pollution of Groundwater in the ESBIKHA Wetland Zone (El Mahmel-W.Khenchela. North East of Algeria)

The Esbikha wetland, covering an area of 612 ha, is located in the state of Khenchela, northeastern Algeria. In recent years, a large agricultural and para-agricultural activity has been developed in the ESBIKHA wetland, leading to an increase in water needs and deterioration in the quality of the resource, especially in light of the climate changes that the world is witnessing and the deterioration of water resources. On this basis, giving water resources priority in terms of studying and preserving is a priority. Within this context, this work aims to better understand the degree of groundwater pollution by nitrogen and phosphorous compounds and suitability for human consumption. For that, 28 groundwater samples were taken from almost the entire plain for a physicochemical study, where the physical properties (pH, temperature, electrical conductivity) were measured directly on the site, while the rest of the chemical properties (Ca, Mg, K, Na, Cl, SO4, HCO3, NH4, NO3, PO4, and NO2) were measured in the laboratory to understand the mechanisms governing the quality of water in the region. We used DIAGRAMMS software for chemical analysis, and this allowed us to determine the chemical facies of the water, and to carry out statistical analysis. We used the Principles Components Analyses (ACP) to highlight the link between the chemical. In addition, ArcGIS was used to map chemical element concentrations and to determine the Pollution spatial distribution by nitrogenous compounds and ortho-phosphates. 75% of the analyzed samples represent a high electrical conductivity greater than 2000 µs/cm, the samples which have a high electrical conductivity are located in the northeastern part of the study area, and the pH varies between 7 and 8. In general, the concentrations of the chemical elements are higher than the concentrations recommended by the World Health Organization (WHO). The Esbikha area is the site of diffuse pollution by nitrogenous compounds and ortho-phosphates (values of 124 mg/l of NO3 and 0.2 mg/l PO4 were observed in many water points). The rise in electrical conductivity is induced by the evaporation and sedimentation of the salts contained in the Esbikha waters. The waters are neutral to alkaline, and this is linked to the nature of the rocks present in the region which are essentially carbonates and evaporates (gypsum). Higher concentrations of pollutants are caused by sewage and excessive use of agricultural fertilizers. Consequently, these wetlands suffer from significant pollution that threatens the ecosystem in general and human health in particular, which requires necessary measures to be taken to reduce this problem.