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Concentration of Copper, Lithium and Manganese were determined in the whole soft tissues of Mytilus galloprovincialis, collected from the two sites (Bni Ansar and Kariat Arekmane) of the Marchica lagoon of Morocco. The mussels were sampled on December and July of 2019. The ability of mussels to accumulate metals was arranged in the following order: Li < Cu < Mn. The levels of heavy metals in M. galloprovincialis were higher (P

Our study was based on using a freshwater aquatic species to assess the short-and long-term toxicity of an organophosphate insecticide commonly adopted by the Moroccan agriculture sector. Recently, groundwater pollution has emerged as one of the most severe environmental challenges, with a particular emphasis on levels of heavy metal pollution. Conservation efforts and efficient management of groundwater resources are required to determine the full scope of this damage. The current research answers the physical-chemical evaluation of the middle Kert basin’s water quality (Mediterranean area, Driouch province, Eastern Morocco) by collecting 42 samples and measuring pH, TDS that vary between 451 and 5841 mg/l, and EC that range from 0.72 to 9.41mS/cm2 according to ISO 5665. The samples were analyzed by ICP-MS and flame atomic absorption spectrometry to detect fluoride and arsenic content. Whose fluoride in the survey area varied from 0.01 mg/l to 2.85 mg/l. The hydro-chemical classification resulting from the Geographic Information System (GIS) statistical data analysis was used to interpret the analytical data on the phenomena responsible for the mineralization. This quantity is considerably higher than the maximum allowable level of 1.5 mg/L, which is the regulation for drinking water in Morocco. It indicates that both natural and artificial factors have contributed to the effects. Most stations have a fluoride concentration in the water, which can be used to identify them. It is a significant amount less than the values that would be ideal; just four wells have concentrations higher than the values that are legally allowed to be. The fluoride levels in the region’s water sources directly result from the natural elements that make up this particular geographic location.The same happened for arsenic, which exceeded 0.1 mg/l in just two samples.

Eutrophication of littoral seawater is estimated to be one of the main threats to marine biota. Therefore, continuous monitoring is necessary to define areas of potential risk. Our work is an essay to explore the possibility of applying the trophic state index (TRIX) to assess the state of eutrophication along the eastern coast of the Moroccan Mediterranean (Ras Kabdana-Saïdia) in concert with a number of hydro chemical parameters and nutrients descriptors aimed at selection of relevant indicators of marine coastal area ecological quality. Seawater samples were studied monthly during 2018. The following environmental parameters have been considered: temperature, salinity, pH, suspended matter, turbidity, dissolved oxygen, saturation levels, nitrite, nitrate, and orthophosphate. Principal Component Analysis was applied in order to figure out and score the most relevant combination of parameters to discriminate between sites and select representative descriptors (pressure/state) of eutrophication. The following variables are defined as relevant descriptors for classification of the sites: nutrients (N, P) and their molar ratios (N/P), the capacity of the system to produce and sustain organic matter (chlorophyll a), and the trophic state index (TRIX). The results show TRIX values below 4, the eutrophication range indicated that there is no ecological risk. The Ras Kabdana-Saïdia is located in an oligotrophic state.

This work aims to study the distribution and quantification of the genus Rhizosolenia known for its abundance and diversity among planktonic diatoms at 9 sampling stations in the Nador lagoon and during 2 seasons (spring and summer 2018). The diatoms collected in the 9 sampling stations were identified morphologically using an inverted optical microscope. A total of 10 species of the genus Rhizosolenia have been listed including: Rhizosolenia bushsolei, R alata forma alata, R bergonii, R cochlea, R hyalina, R imbricata, R setigera, R bushsolei, Rhizosolenia sp and R styliformis. The quantitative analysis of the species collected shows that the maximum cell density was recorded respectively at stations 9 and 7 located in the center of the Nador lagoon, with values of 21680 Cell/l and 15710 Cell/l. However, the minimum cell density was recorded at station 5 corresponding to Oued Bou Areg located at the edge of the lagoon with a value of 5120 Cell/l.

The monthly variations in metal concentration of Cadmium (Cd), Zinc (Zn) and Chromium (Cr) were determined in tissues of Mytilus galloprovincialis and seawater obtained from the mussel farm installed along the Al Hoceima coasts, during the sampling period of 2018. The heavy metals encountered in the bivalves were higher than those observed in their environment with a decreasing order of Zn > Cr > Cd. The results also showed a decreasing trend for the metals studied during the summer sampling campaign. The maximum values were obtained during the wet periods. The monthly variations in trace metals observed in the mussel tissues were due to environmental parameters and the physiological state of the bivalves. Our results revealed that the average concentrations of pollutants found in M. galloprovincialis were below the limits allowed by the Food and Agriculture Organization of the United Nations (FAO) which are 2.0, 1000 and 1.0 mg/kg, for Cd, Zn and Cr, respectively in molluscan shellfish for human consumption. Therefore, the trace elements present in the tissues of Al Hoceima shore mussels do not represent a risk to human health associated with their consumption, even during the period of their maximum bioaccumulation. Our work highlights the potential use of Mytilus galloprovincialis in the Biomonitoring of metallic pollutants in this region of the northern Moroccan coasts.

The present work reports the synergistic and inhibitory adsorption effects involved in the multicomponent adsorption of heavy metal ions (Fe (II), Pb (II)), and major elements from oil mill liquid waste (OMW) using natural bentonite as adsorbent cames from Nador (North-East Morocco). Morocco is one of the most olive oil producing Mediterranean countries. This industry, which is so beneficial to the national economy, leaves two toxic and non-biodegradable residues (liquid/solid). OMW or margin is a current liquid pollutant that has been listed by the United States Environmental Protection Agency (EPA). The classical methods used for phenol removal are expensive or limited to large-scale applications such as biological and thermal decomposition methods. The margins used in the studies were collected from a semimodern oil mill (Nador-Morocco). The results of the physicochemical analyses showed that the effluents of the oil mills showed that they are highly polluted, in particular the suspended solids, COD, and iron contents of around 154.82 (mg/l) and copper 31.72 (mg/l). Samples of OMW mixed with raw bentonites at different percentages vary between 10 % and 80 %. Different interactions between bentonite and metal ions dealing with the decrease of the concentrations. This study proves that this bentonite is an effective adsorbent for the elimination of heavy metals from OMW.

The goal of this study is to look into the dominance of diatoms, specifically the genus “Pseudo-Nitzschia Sp” at the Nador lagoon level and how it relates to the physicochemical parameters of the environment. From the four sampling stations and for two seasons (spring and summer 2018). This diatom of the genus “Pseudo-Nitzschia Sp” includes toxic species capable of producing domoic acid (DA), a neurotoxin responsible for amnesic intoxication syndrome in humans. During sampling, the species “PseudoNitzschia Sp” showed variable cell densities between stations and seasons. The dominate microalgae were observed during the spring period with a maximum concentration of (4000 Cells / l). And a low viscosity during the summer seasons (140 Cells / l).

Mytilus galloprovincialis are commonly used as heavy metal biomonitors across the world. In the present work, the contents of three elements (Al, As, Li) were analyzed in Mytilus galloprovincialis using Inductively Coupled Plasma – Optical Emission Spectrometry (ICP-OES 720-ES). Samples of soft tissues are collected monthly in 2020, from three sites of the mussel farming facilities installed in the Al Hoceima Sea. The decreasing order of the mean element contents in mussel tissues was Al > As > Li. The lowest values of metallic elements were found in summer and the highest contents were indicated in winter. Positive correlations were indicated between these elements and chlorophyll a indicating the importance of diet for the bioaccumulation of metals in mussels. In addition, our results show that the temperature and the salinity increase with the decreasing of metals bioavailability suggesting the influence of chemical properties and physical kinetics changes in the solution. On the other hand, the strong correlations observed for metal contents in mussel tissues can be elucidated by their common sources. The results of this study may be useful in the use of M. galloprovincialis, in the environmental biomonitoring studies.

The present work reports the application to reduction of the organic matter and nutrients in oil mill liquid waste (OMW), using the natural calcium bentonite from Morocco as adsorbent. The margine is characterized by a high concentration of low biodegradable and highly toxic organic matter. In order to evaluated the reduction capacity of bentonite to remove organic matter and nutrients, characterization mineralogical, chemical and also morphological of adsorbent were conducted. During the experiment and in the scenarios studied, all the total of parameters adsorbed was strongly depend on the percentage of bentonite. While, the percentage of pH of OMW was gradually decreased from 4.03 to 8. 04. The COD concentrations were decreased from 172.72 to 29.71 g/l, and also the phosphorus concentrations were decreased from 1.16 to 0.29 g/l. The electrical conductivity decrease in this work from 16.93 to 0.17 mS/cm. This present work proves that calcium bentonite is an effective adsorbent for the elimination the nutrients and organic compound.