Hierarchization of Physicochemical Factors during Simultaneous Removal of Lead and Copper from the Marrakech Municipal Discharge Soils

Heavy metals became a great concern for scientists due to their harmful action on the environment and human life. EDTA and NTA chelation capacity were used to assess soil decontamination. The effect of pH, ligand, soil solution contact time with agitation, soil solution ratio, and particle size were investigated, in order to prioritize them, using the design of experiment methodology (Doe): pH was the most influential factor while the ratio mass of the soil by the volume of the solution and particle size were of equal importance. EDTA was more effective as a chelator than NTA in removing metals from the soil. The contact time was not a significant factor; a contact time of 10 minutes was sufficient to extract the two metals studied. An extraction efficiency of 45% was achieved for Pb and 85% for Cu without optimization process

Optimization of Physicochemical Parameters during the Electrocoagulation Cadmium Elimination

The increased use of fertilizers from phosphates in agriculture generates water pollution by heavy metals contained in these phosphates at levels higher than the standards. In our study, we used a cadmium nitrate Cd(NO3)2 solution to simulate artificially polluted water, whose decontamination efficiency will be evaluated by an electrocoagulation/flotation process. During this work, we aimed to optimize the electrocoagulation process according to the following factors: initial pH of the solution, density of the electrolysis current, cell time, and nature of the supporting electrolyte and its concentration. The criteria adopted during the optimization of the process are relatively different from those used in similar studies. Indeed, we have tried to achieve maximum efficiency and also seeking to minimize costs and facilitate implementation. We achieved a 98% Cd removal efficiency from the solution at pH = 7, J = 6.25 A/m2, t = 10 min, and [K2SO4] = 0.01 M. In addition, during the characterization of the flocs obtained as a supernatant, we first highlighted the presence of Cd in this gelatinous body and then the relatively easy volatility of Cd as well as that of aluminum oxide (Al2O3)