Assessing the organic pollution of surface water of Medjerda watershed (NE Algeria)

Abstract

Water quality in the Northern part of MellegueMedjerda watershed (East Algeria) has been adversely affected by important pollutants discharged into the Medjerda wadi without, in most cases, any treatment. Chemical and physical degradation are due to agricultural and industrial practices and domestic wastewaters. Over a three-month period, a study of the low-flow water quality characteristics throughout Medjerda wadi was undertaken. Longitudinal profiles of water quality were constructed using data from fourteen sites. All sewage, agricultural, and industrial inputs were included. Analyzed properties were nutrients (NO 3 -, NO 2 -, NH 4 ? , and PO 4 3-), Biochemical oxygen demand after five days (BOD 5 ), chemical oxygen demand (COD), and dissolved oxygen (DO). Along Medjerda wadi, all values change because of conditions specific to each sampling station. Nitrate was the most important form of nitrogen-element load (94%). Its concentration reached 34.3 mg L -1 at OM 4 point, downstream of domestic wastewater discharges. The spatial evolution of the organic pollution index (OPI) shows that the wastewater effluent constitutes the main source of pollution. Indeed, water quality goes from a moderate pollution state at some sampling stations not or slightly affected by wastewaters discharges to a very strong pollution state (OPI of about 1.75) downstream of the domestic effluents inputs of Souk-Ahras city.

Effect of Hartha and Najibia power plants on water quality indices of Shatt Al-Arab River, south of Iraq

“…The phenomenon of eutrophication leads to a decrease in the level of oxygen in water and loss of biological diversity (Vousta et al 2001). Four parameters (BOD 5 , NH 4 , NO 2 , and PO 4 ) are selected for evaluating OPI (Guasmi et al 2010). For evaluating the effect of power plants (Hartha and Najibia) on OPI in Shatt Al-Arab River, two sites are selected for sampling water: the first one is located (1000 m) north of the Hartha power plant (S2), while the second one is located at the confluence of Shatt Al-Arab River and Qarmat Ali River (S6) during the DS (August, 2016) and the WS (January, 2017) (see Tables 1 and 2).…”

A coupled modeling approach to evaluate nitrogen retention within the Shanmei Reservoir watershed, China

“…Social development and human activities, such as fertilizer application and discharge of livestock waste water and domestic sewage, have caused serious non-point pollution at the watershed scale. This has resulted in the deterioration of surface water quality and the eutrophication of rivers, lakes and reservoirs (Guasmi et al, 2010;Abdelkader et al, 2012), greatly increasing the quantity of nutrients transported by rivers from upland watersheds to the ocean (Yan et al, 2010). To fulfill the growing water demands, a large number of water conservation projects have been built to retain river water in dams and significantly changed the hydrological characteristics, physical transformations, nutrient transfers and transport fluxes (Kelly, 2001;Klaver et al, 2007).…”

Assessing the Organic Pollution and Aquaculture Activity of Surface water at Shatt-Al-Arab Estuary Southern of Iraq

“…The OPI was calculated based on Guasmi et al (2010) as the average number of classes of four properties (BOD5, NH4, NO2, PO4). The class limits of pollutants and the grid evaluation of organic pollution types were showed at Table 1 and 2.…”