This study analyses the seasonal distribution in the superficial sediments of the Marchica watershed of trace and major elements, grain size, and total organic carbon. Samples were taken during the wet and dry seasons of 2018 in the mainstream valleys carrying the discharges to the Marchica Lagoon. Ecotoxicological indices (Enrichment Factor, Contamination Factor, Pollution-Load Index) and sedimen-quality guidelines were used to evaluate the ecotoxicological risk. The results revealed during both wet and dry seasons contamination by lead in all stream valleys. The northwest stream valley, characterized by some industrial activities, and the stream valley crossing the abandoned mine were the most polluted by zinc and copper. Minimal pollution for Cr, Co, and Ba was found during both the wet and dry seasons. Despite the restoration actions achieved around the Ramsar site of Marchica lagoon during the last decades, the watershed continues to have a negative impact on this ecosystem. Therefore, an environmental management strategy isnecessary, taking into account the rehabilitation of the abandoned mining sites, the rational use of pesticides and fertilizers in agriculture, and the environmental responsibility of industrial companies, especially those installed before the implementation of the national law on environmental impact studies.

The goal behind this work is defined as the study of the quality of water from karst springs near quarries exploiting limestone rock in order to assess its adequacy with domestic uses. At that end, a study at the mountain level was carried out. This mountain is in the Haouz area, in Tetouan, which is located north of Morocco and shelters active quarries. This research is based on the assessment of the physico-chemical parameters of the spring water used by local residents and located near this industry. The water quality evaluation was carried out by comparing the recorded values, according to Moroccan Standards related to the quality of water for human use. The review of some parameter’s indicative of water pollution (T °, pH, electrical conductivity, dissolved oxygen, turbidity, total dissolved solids and the alkalimetric total title) revealed that the quality of the studied spring water is good and does not present any health risk to the users of this water during the winter season.

The main purpose of this study was to investigate the impact of human activities, geochemical background and seasons on pollutant pathway. Surface water, groundwater and sediments were assessed to highlight and confirm those impacts. Sixteen physico-chemical parameters were measured (T°,

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.

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