Research Outputs
Treatment of landfill leachates from Fez city (Morocco) using a sequence of aerobic and Fenton processes
This study aims: (a) to characterize the raw leachate generated in the landfill of Fez city, and (b) to evaluate the feasibility to apply an aerobic treatment followed by a Fenton oxidation process. The aerobic treatment was conducted in a suspended grow bioreactor during 60 days. The bioreactor was monitored every 3 days, following the variation of pH, chemical oxygen demand (COD), biochemical oxygen demand (BOD5), turbidity, conductivity, color number (CN), total suspended solids (TSS), nitrates (NO3−-N), nitrites (NO2−-N), and the absorbance values of the UV–vis spectrum. Results showed an elimination of41%, 31%, 50%, 52%, and 37%, on COD, BOD5, color number (CN), NO2−-N and NO3−-N, respectively. Thereafter, a Fenton oxidation process was successfully applied to the biological pre-treated leachate, improving the removal of COD, BOD5 and color to 73%, 99.5% and 94%, respectively.
Optimization of Fenton process operating conditions for the treatment of the landfill leachate of Fez city (Morocco)
In this work, the landfll leachate of Fez city (Morocco) is characterized physicochemically and the feasibility to apply a Fenton process is evaluated. A design of experiments based on Box–Behnken combined with a response surface methodology was used to assess the efect of three operating variables (pH, Fe2+ and H2O2 dosages) on two target responses: COD and color removal. The results of the analysis of variances demonstrate that both responses are signifcantly afected by Fe2+ dosage and pH. Statistical and graphical analyses show that maximum efciencies of 85% and 96% are obtained in terms of COD and color removal, respectively, when operating conditions are set in pH=2.8, [Fe2+]=1621 mg L−1 and [H2O2]=2500 mg L−1.
Use of coagulation-flocculation process for the treatment of the landfill leachates of Casablanca city (Morocco)
This study aims to investigate the feasibility to apply a coagulation-flocculation process to treat the landfill leachate of the municipal solid waste of Casablanca city (Morocco). Three types of coagulants are assessed: lime (Ca(OH)2), ferric chloride (FeCl3), and alum (Al2(SO4)3). Optimum conditions in terms of the removal of chemical oxygen demand (COD), heavy metals, colour and turbidity contents are determined, using a standard jar test apparatus. Optimum coagulant dosages of 52.5 g Ca(OH)2.l-1, 12 g FeCl3.l-1 and 22.5 g Al2(SO4)3.l-1 are obtained. Lime allows to remove 66.25% of COD, 98% of turbidity, 80% of colour with a low sludge volume generation (30%). When the optimum coagulant dose of FeCl3 is applied a 62.5% of COD, 92.5% of turbidity, 82% of colour are removed with less sludge volume generation (21%).Whereas when Al2(SO4)3 is used 11% COD and 6% of turbidity removal are obtained with a slightly lower sludge volume generation (11%). Regarding the analysis of metallic elements, the results show that a substantial elimination of heavy metals is reached, particularly of Cd, Cr, Cu, Fe, Ni and Pb. Treatment with lime shows a greater affinity to Cr (86%) and lower to Fe (60%). Ferric chloride allows to eliminate most of the detected metal elements with a high affinity toward Cd, Cu, Ni, Cr and Zn. Alum shows to be very suitable for Ni, Pb, Cr elimination with 95 %, 94 % and 93% removal efficiency, respectively. These results show that coagulation-flocculation could be used as a promising process for the pretreatment of landfill leachates of Casablanca city.