because of conditions specific to each sampling station
"Water quality in the Northern part of Mellegue-Medjerda 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," scientists writing in the journal Environmental Earth Sciences report.
"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 (NO3 (-), NO2 (-), NH4 (+), and PO4 (3-)), Biochemical oxygen demand after five days (BOD5), 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 OM4 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," wrote I. Guasmi and colleagues.
The researchers concluded: "Indeed, water quality goes from a moderate pollution state at some sampling stations not or slightly affected by wastewaters tiffany discharges to a very strong pollution state (OPI of about 1.75) downstream of the domestic effluents inputs of Souk-Ahras city."Guasmi and colleagues published their study in Environmental Earth Sciences (Assessing the organic pollution of surface water of Medjerda watershed (NE Algeria). Environmental Earth Sciences, 2010;60(5):985-992).
"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 (NO3 (-), NO2 (-), NH4 (+), and PO4 (3-)), Biochemical oxygen demand after five days (BOD5), 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 OM4 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," wrote I. Guasmi and colleagues.
The researchers concluded: "Indeed, water quality goes from a moderate pollution state at some sampling stations not or slightly affected by wastewaters tiffany discharges to a very strong pollution state (OPI of about 1.75) downstream of the domestic effluents inputs of Souk-Ahras city."Guasmi and colleagues published their study in Environmental Earth Sciences (Assessing the organic pollution of surface water of Medjerda watershed (NE Algeria). Environmental Earth Sciences, 2010;60(5):985-992).
