Pollutant load discharge from a Southwestern Mediterranean river (Mazafran River, Algeria) and its impact on the coastal environment

Arabian Journal of Geosciences(2023)

Cited 5|Views6
No score
Abstract
This work aimed to assess the water quality of Mazafran River, the most important wadi in Bou-Ismail Bay, and to study the impact of its pollutant discharges into the adjacent coastal waters. To this end, a sampling campaign (August 2016) was conducted at various locations in the lower Mazafran River and the adjacent coastal waters. Collected river water samples were analysed for different pollutants and water quality parameters (chemical oxygen demand COD, biochemical oxygen demand BOD 5 , total Kjeldahl nitrogen TKN, total phosphorus TP, chlorophyll Chl a and dissolved oxygen DO). The coastal receiving waters were monitored for nutrients (NO 3 , NO 2 , PO 4 , SiO 2 ) and nutrient stoichiometry (N/P/Si), suspended particulate matter (SPM) and Chl a. Based on these results, the extent of the pollution plume was assessed. Principal component analysis (PCA) was performed using the field data to evaluate the influence of the studied parameters on the sampling station characteristics. Mazafran surface water monitoring indicates poor water quality conditions for all sampling stations, primarily because of upstream wastewater discharges. The upstream station received the highest biodegradable organic load (COD/BOD 5 ratio of 1.23) and TP level (9.7 mg/l). The midstream and downstream stations were characterised by an increase in COD/BOD 5 ratio (1.59 and 2.36, respectively) and high concentrations of TKN (85 and 54 mg/l, respectively), probably resulting from the inputs of nearby industrial effluents and nutrients runoffs. The pollutant load carried by the Mazafran River entering the coastal waters contributed to an extra enrichment of nutrients, an imbalance in N/P/Si ratio leading to a case of Si limitation, an increase of SPM concentrations and a shift in chlorophyll content. The dynamic of the pollution plume was mainly limited by the low flow discharge of the river and current circulation, which resulted in a decreasing gradient from the mouth to the open sea and from east to west. Overall, our results highlighted the heavy pollution of the Mazafran River and its negative impact on the coastal water characteristics of the surrounding area.
More
Translated text
Key words
Coastal river discharges,Mazafran River,Pollutant loads,Nutrients,Coastal waters
AI Read Science
Must-Reading Tree
Example
Generate MRT to find the research sequence of this paper
Chat Paper
Summary is being generated by the instructions you defined