Nouha El Allaoui’s research while affiliated with Sidi Mohamed Ben Abdellah University and other places

In recent years, the quality of the surface water of the city of Fez has deteriorated due to the development of various anthropic activities, ill-considered modernization, unregulated discharge of wastewater and solid waste. This is a worrying threat to human health and the environment. Previous studies on these wadis have shown that Tghat and Zhoun wadis are the most polluted [1]; [2]; [3]. Adequate treatment of effluents upstream is therefore of crucial importance. The objective of this study is to contribute to the treatment of endocrine pollutants discharged upstream of these two wadis after their characterization and monitoring of their pollutant load for six months (El Madani et al., 2019). The most polluted wadis of the city of Fez [2] by coagulation-flocculation.The results showed that these effluents have a medium faecal load and are loaded by organic pollution at the limit of biodegradability rich in nitrogen and phosphorus matter and a high metallic load with endocrine disrupting effect, mainly Cr, As, Pb and Cd.The treatment of these pollutants by coagulation-flocculation with aluminum sulphate of the effluents studied under optimal conditions of pH, a dose of coagulant and flocculant and coagulation and flocculation agitation speeds, allowed the reduction of almost all the organic matter and 90 to 96% of the metal load.

Bipolar electrocoagulation with aluminum sacrificial electrodes was designed to simultaneously remove of Cr(VI), phosphorus, chemical oxygen demand and turbidity from both tanning, domestic and industrial wastewater. The experimental setup was demonstrated in semi‐industrial scale for remediation of effluents released from Fez city (Morocco), which exhibited in highly variable composition and pH. The results showed that the elimination levels are enhancing with increasing of the energy consumption and electrode amount. The optimum conditions of the electrocoagulation process to reduce the pollutants in over 90% were identified at current density of 5 mA.cm–2 that takes around 10 to 30 min at neutral pH. Thus, the proposed method could be considered as an effective approach in the conventional treatment of wastewater from artisanal activities.

The large-scale removal of colloidal contaminants from artisanal activities was conducted through optimized bipolar electrocoagulation with lower energy consumption and aluminum sacrificial electrodes. As a result, over 90% simultaneous removal of total chromium, phosphorus, chemical oxygen demand and turbidity contents was achieved for relative short time (10–30 min), neutral pH of 7.0–7.5 and minimized current density. By optimization of the applied electrochemical parameters the elimination of carcinogenic colloidal chromium and organic mixture was modeled in a reproducible manner, and the reached purification levels of the effluents were acceptable for their reuse in the household. The practical usage of reported electrocoagulation design was successfully demonstrated as an effective alternative of the current conventional method for treatment of the tanning, domestic and artisanal industrial wastewater in Fez city, Morocco.

The sewerage of Fez City receives different industrial effluents (tannery, brassware, dyeing, pottery...). The district of Ain Nokbi includes most of the craft activities, which discharge untreated into public networks or directly to Oued Sebou. The space-time monitoring of physical-chemical parameters, compared to Moroccan standard of rejection, reveals that the wastewaters from this district and surroundings, containing huge quantities of SS, cyanide, mineral and organic matter with variable biodegradability, and a very high metal load in chromium presented as chromium III which can reach as average values (4009 ; 927mg.L-1) in SS, (3329 ; 1342 mgO2.L-1 ) in COD, (251.1 ; 171.7 mg.L-1) TKN, (307 ; 101 mg.L-1) in CN- and (97 ; 12 mg.L-1) Cr III respectively for P1 and P2. While statistical analysis revealed a strong positive correlation between the chemical parameters. They are opposed to the physical parameters of the (F1 * F2) CPA plan. Disposing of this wastewater, either in networks or consolidations in nature can have adverse effects on the biological treatment station of Fez city, also on the health of the population and the aquatic life of Oued Sebou. In this sense a physic-chemical pre-treatment of these effluents is a must to ensure a healthy environment in this town.