Oued Nfifikh is a coastal stream of the Bouregreg and Chaouia watershed (Morocco). It passes through many rural and urban areas and receives different types of liquid and solid discharges from anthropogenic activities adopted along the watercourse. This study aims to evaluate the physicochemical quality of the water from the most accessible sites upstream and downstream of Oued Nfifikh, along with highlighting the impact of human activities on these waters' quality. For this purpose, water samples were collected and analyzed within normalized methods. Statistical analysis of the collected data shows significant spatial variations (p value < 0.05) for pH, electrical conductivity, nitrate and chloride, and for metallic trace elements (Zn, Fe, Ba, Mn, Cr and Al). Unlike (temperature, Pb, Ni, Cu and Cd), whose values do not present statistically significant variations (p value > 0.05). The study of the physicochemical quality reveals that the waters at the upstream are classed as good quality, except for site (S2), located at the upstream part of the river, it is affected by human activities. Consequently, its physicochemical composition is quite similar to that of waters of poor quality at the downstream sites. The Principal Component Analysis of the results followed by the Ascending Hierarchical Classification on the same data matrix allowed to regroup the sampling sites with similar characteristics into three distinct groups. A group of highly mineralized waters, a second group dominated by elements indicating urban pollution, and a group of waters with low mineral content and low metallic contamination indicating agricultural pollution.

As part of eco-toxicological tests on Artemia salina, the impact of the most commonly used fertilizers in Morocco was assessed (Ammonium Sulfate, Ammonium Nitrate, and a mixture of Nitrogen 10%, Phosphorus 30% and Potassium 10%), with Potassium Bichromate (K 2 Cr 2 O 7 ) as reference substance at different concentrations (10,20, 40, 80, 160, 320 mg/l), for 24 hours. The results of the statistical study revealed that the lethal effects caused by the three agrochemicals increase with the concentration and vary from one substance to another in a significant way. There is a higher sensitivity to ammonium sulphate (the concentration that kills 50% of the animals: 37.32 mg/l ± 6.09) followed by ammonium nitrate the concentration that kills 50% of the animals: 110.7 mg/l ± 7.11), and a mixture of Nitrogen 10%, Phosphorus 30% and Potassium 10% (the concentration that kills 50% of the animals: 143.13 mg/l ± 23.12). Therefore, Artemia salina exhibits sensitivity to agrochemicals and can be considered as a good biomonitoring tool for future toxicological analysis of agrochemicals.

The surface treatment industry generates effluents with a high load of highly toxic chemicals which must be treated under increasingly stringent regulation. The aim of this study was to treat the effluents of surface treatment unit of an aeronautical industry by the electrocoagulation process using aluminium electrodes. This process is used to study the performance to remove colloidal load, significant amount of oxidizable material and high levels of various metal elements (Cr, Fe, Zn, Cu and Al) from these effluents, under optimum conditions of pH 7, 8.6A of current intensity and 60 min of application. The electrocoagulation process was found to be effective in reducing turbidity (97.12%), COD (97.5%), SS (97.84%) and conductivity (96.82%), hexavalent chromium (99.99%), Zn (96.82%), Cu (94.3%), Iron (99.9%), Al (91.96%). The treated effluent conformed to the Moroccan standards of surface treatment discharge.

Oued Nfifikh is among the least studied Moroccan rivers. Thus, the primary aim of this study was to shed light on the quality of this undervalued stream. Its downstream part is affected by one of the most crucial environmental issues. It receives the discharges of wastewater evacuated precariously without prior treatment, which might lead to the degradation of the overall ecological status of this fluvial hydrosystem. This research work aimed to study the physicochemical water quality downstream the river Nfifikh through a monthly monitoring of the physicochemical parameters' indicator of pollution, from August 2018 to July 2019. The results obtained show that the stream is exposed to high pollution which is mainly organic. Consequently, the wastewater represents a major cause of water quality degradation of this receiving environment: ecological and health impacts are therefore to be expected.