Wyniki wyszukiwania - BazTech

Ograniczanie wyników

Znaleziono wyników: 2

Liczba wyników na stronie

Wyniki wyszukiwania

Sortuj według:

Ogranicz wyniki do:

Physico-Chemical and Biological Characteristics of the Oum Er Rbia Estuary (North Atlantic Moroccan Coast) – Impact of Urban Wastewater

Bengriche Rachida, Bouchafra El Mostafa, Chaouite Jamila, Nafia Mohammed, Moncef Mohammed

Journal of Ecological Engineering

2024

Vol. 25, nr 1

1--16

This study aimed to monitor abiotic factors at three stations in the Oum Er Rbia estuary, not far from the mouth. The stations were situated upstream (S1), in front (S2) and downstream (S3) from the discharge of urban wastewater from the town of Azemmour, which is discharged directly without treatment near the estuary mouth. The selection of these stations appeared appropriate to assessing the quality of the waters, which are influenced by both marine hydrodynamics resulting from very low freshwater inflows and sewage discharges. Monitoring of several parameters, including temperature, pH, dissolved oxygen, conductivity, salinity, turbidity, as well as the content of chlorophyll α and pheopigments, enabled the examination of the impact of marine hydrodynamics and the and the specific characteristics of the three surveyed stations. The analyses were performed using R software version 4.2.0. The results obtained indicate that the studied physico-chemical and biological parameters exhibited variations with significant correlations. Statistical approaches allowed the determination of profiles for stations S1, S2 and S3. It is evident that S1 (located slightly far from the discharge) showed a profile that tended to differ from the other two stations, S2 and S3, especially for certain parameters (temperature, pH, turbidity, and chlorophyll a). On the other hand, all stations were impacted to some extent by the discharge of wastewater during rising tides. The present study can serve as an assessment tool to support decision-making regarding the physico-chemical quality of the waters of the Oum Er Rbia estuary.

Efflorescence of the Potentially Harmful Dinoflagellate Prorocentrum micans in the Oum Er Rbia Estuary – North Atlantic Moroccan Coasts

Bengriche Rachida, Bouchafra El Mostafa, Chaouite Jamila, Moncef Mohammed

Ecological Engineering & Environmental Technology

2023

Vol. 24, iss. 6

250--256

The present work addressed the study an episode of red waters of great extent, which was observed off the Oum Er Rbia estuary in spring 2019. The responsible species was Prorocentrum micans. The study was carried out on three stations with different characteristics, distributed in the estuary upstream and downstream of an urban wastewater discharge. The cell densities observed were maximum in March 2019. Some environmental parameters (temperature, salinity, dissolved oxygen, chlorophyll (a) and pheopigments) were simultaneously recorded. The P. micans densities increased from downstream to upstream with cell concentrations of 1.03×105 cell/l in S3, 9.1×106 cell/l in S2 and 14.11×107 cell/lin S1. The contribution of P. micans to the total dinoflagellates density was higher and reached 99.54% in station S1. These blooms would be associated with high concentrations of chlorophyll (a) and pheopigments, which equaled 40 μg/l and 909 μg/l, respectively, and dissolved oxygen supersaturations (17.05 mg/l). This phenomenon also corresponded to a marked decrease in salinity. According to the application of the Kruskal-Wallis test, the difference was found to be significant between the three stations (p = 0.0034). In addition, densities were higher in surface waters than in bottom waters at all three stations. However, this difference did not appear to be statistically significant (p > 0.05).