Search

Ibn Tofail University of Kenitra, Morocco, is committed to a national policy of control and mobilization of water resources and the adoption of a planning approach and integrated water management. Within this framework, the university, which contains 40,000 students, produces a quantity of wastewater of 200 m3 per day. After treatment, the water is used for watering the university’s green space. The treatment process chosen is a membrane bioreactor (MBR), which is considered to be energy intensive. Therefore, the production of energy for the station will be made by renewable energy wind and photovoltaic (PV). The dimensioning of the MBR was made by a research department, which estimated that the energy necessary for the station is 1061.76 kW h/day. The aim of this work is to dimension and optimize the platform for the production of energy, using the Matlab program for the wind turbine and the PVsyst program for PV. The results of coupling our plant with an on-grid PV system and wind turbine show that it was able to reach an electrical coverage of about 72% of the wastewater treatment (WWT) plant’s energy needs. Thus, an estimated reduction of electricity of 0.53 euro on each m3 of water produced by the WWT plant and thus 106.76 euro on the 200 m3 produced daily by the station.

The aim of this research is to compare the influence of initial ion concentration on nitrate transfer in nanofiltration (NF) and reverse osmosis (RO) membranes. To accomplish this study, three mathematical models were employed: Kedem-Katchalsky (KK), Spiegler-Kedem (SK), and Nernst-Planck model coupled with film theory (NP-FT). While the KK and SK models do not consider the concentration polarization layer (CP) or electrostatic interaction, they can determine the convective concentration (Cconv), diffusive flux (Jdiff), reflection coefficient (σ), and permeability (Ps) of nitrate ions. The NP-FT model considers the impact of the CP layer and enables the assessment of the thickness (δ) of the CP layer, Ps, and σ. The research was conducted on actual groundwater that was doped with NaNO3 at various initial nitrate concentrations (IC) (50, 100, 200, 300, and 400 mg/L) using the NE90 membrane for NF and RE-BN for RO. The obtained results indicate that the rejection of nitrate ions depends on the pressure and initial concentration, with a more significant dependence observed in the case of the NE90 membrane. The KK and SK models' parameters (Cconv, Jdiff, Ps, and σ) depend on the IC, but this dependence is more pronounced for NF than RO. Both types of ion transfer, convection and diffusion, are present in both membranes with a predominance of diffusion, and their contribution depends on IC. The thickness δ determined by the NP-FT model for both membranes was negligible for RO, and about 10-8 m for NF. [ABSTRACT FROM AUTHOR]

The manufacture of the handcrafted items is carried out in a succession of deposit baths and rinses. However, this process gives rise to complex and highly loaded effluents, including a mixture of heavy metals (Cu(II), Ag(I) and Ni(II)). Therefore, to meet the Moroccan discharge limits, it is necessary to treat these effluents before discharging them into the natural environment. The objective of this study is the comparison of electrodialysis (ED) and reverse osmosis (RO) in the reduction of heavy metals in brassware wastewater of the city of Fez (Morocco). The first part is devoted to the study of the influence of the operating parameters of RO (transmembrane pressure (TMP) and recovery rate) on the quality of the permeate. The rejection (R) of metal ions (Cu(II), Ag(I) and Ni(II)) increases with TMP, but decreases with the increase in the recovery rate. The maximum values of 96%, 66.39% and 99.6% have been reached for Cu(II), Ag(I) and Ni(II), respectively. The second part of this work focuses on the feasibility of ED in the removal of heavy metals. The influence of the demineralization rate (DR) on the quality of the dilute is studied. Results show that the removal rate of cations (Cu(II), Ag(I) and Ni(II)) increases with the increase of DR and reaches, respectively 98%, 95% and 97% for a DR of 90%. Finally, a comparison between RO and ED based on the water quality delivered and the energy consumed is performed under optimal operating conditions. [ABSTRACT FROM AUTHOR]

The groundwater in the region of Sidi Taibi (Kenitra, Morocco) is intended for human consumption and agriculture. However, this water is largely contaminated with nitrate, which poses a serious threat to human health. This situation is at the origin of the construction in 2014 of the first nitrate removal plant, using nanofiltration (NF) coupled to an electrochemical disinfection system, and supplied with renewable energies (photovoltaic and wind). The unit was installed at Al Annouar high school in Sidi Taibi to supply 1,200 students with potable water, with a production capacity of 500 L/h (3 L/d/student). The local groundwater is nitrated and slightly brackish. This work aims at studying the impact of recycled ratios of brine on nitrate removal and electrochemical disinfection performances. For this reason, two configurations are evaluated separately at a different recycled ratio of brine. The studied configurations are NF90-NF90 and NF270-NF90. The results show that NF90-NF90 configuration with brine recycling can only be technically feasible under the following conditions: brine recycling ratio of 70%, a recovery rate of 85% and a flow rate of 260 L/h intended to be blended with the nanofiltered water which is directed to the electrolytic cell (first mode). On the other hand, NF270-NF90 configuration presents two installations that are feasible to be combined with the electrolyzer. The first one is set for a recovery rate of 60% and a brine recycling ratio of 40% (second mode). The second one is optimized for a recovery rate of 75% and a recycled ratio of the brine of 10% (third mode). The three optimized modes present remarkable qualitative, quantitative, and energy performances. [ABSTRACT FROM AUTHOR]