Characterization of water and sediment quality of Oued Laya (Sousse/Tunisia)

In tunisia,the economic,industrial and agricultural development represents a potential threat to the quality of water resources by the lack of control of effluent discharge into the natural environment. furthermore,the national policy for the management and protection of natural environment quality is not sufficiently advanced. indeed,there is no tunisian standard for monitoring the quality of water and sediments of rivers. our paper aims to provide an inventory of water and sediment quality of oued laya located in the zone of akouda in sousse region (tunisia) which proved to be a major nuisance for the residents. six waters and two sediment samples were collected for analysis. water analyzes are focused on some physico-chemical parameters,ammonium,phosphorus content and heavy metals. for the sediments,the analyses concerned heavy metals and polycyclic aromatic hydrocarbons (pah). furthermore,in the absence of tunisian standard,the french system seq-eau was used to assess the quality of water and sediment of oued laya for the biology aptitude. for water,results show,generally,a high organic and oxydible matter,and a contamination by phosphorus content which justifies the eutrophication of the river by the presence of algae. some heavy metals (cadmium,copper,chromium,nickel,tin,selenium,manganese,iron) were quantified but their concentrations were below the accepted standard used in this study. we can also note the absence of mercury,arsenic,zinc and antimony in all analyzed water samples. for sediments,analyzes show their contamination by heavy metals and pahs. according to the french standard,poor quality can be attributed to oued laya sediments.