The performance of the electrocoagulation treatment of synthetic food dye waste industry was studied using iron anode. The influence of several parameters as electrolysis current, chloride concentration, electrolysis time and pH was investigated. In order to verify these factors and their impact on the discoloration efficiency, an experimental design model was established. The mathematical model was created using a rotatable, uniform and central composite design. This model described the color removal efficiency and the energy consumption according to the studied parameters. The graphical representation of the model according to the parameters allowed us to define optimal treatment conditions. The optimal values of electrolysis current, chloride concentration, electrolysis time and pH were respectively 14.4 mA/cm 2 , 5.76 g/L, 39 mn and 7. 94.52% of color removal efficiency is achieved with an energy consumption of 3.90 KWh/m 3 .

The discoloration of Carmoisine at an initial concentration of 1 g/L, by the Fenton process (Fe2+/ H2O2) has been studied. The efficiency of this process in the discoloration of Carmoisine, as well as the influence of the reaction parameters, was discussed. The effects of initial pH, Fe2+ and H2O2 concentrations, and treatment duration on the discoloration kinetic were evaluated. Our results showed that the best discoloration efficiency has reached 94 % and was achieved in 20 minutes of treatment with 3.57 mmol/L Fe2+, 194.1 mmol/L H2O2, at pH = 3. The discoloration kinetics of the carmoisine followed the BMG model.

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The incineration of non-hazardous solid waste and its use as alternative fuel in cement manufacturing process was studied and simulated under the effect of air flow acceleration in a laboratory scale reactor. Firstly, analysis of the different waste materials (textile, wood and paper) was performed separately, showing that textile samples presented the highest levels of heavy metals (H.M). In the course of a test run using solid recovered fuel (SRF), the mass balance of heavy metals revealed that lead and chromium probably volatilized during firing while arsenic, cadmium and zinc were trapped in clinker. As to gaseous emissions, heavy metals concentration in the stack remained relatively low and below the standard limits. Secondly, the temperature and concentration of gases flue was monitored. It was shown that the combustion regime is characterized by low reaction temperatures and an oxygen-deficient environment. Air injection rate affected significantly the formation and degradation mechanisms of the emitted gases concentrations, particularly CO, CO2, NO, NOx, SO2. Textile waste exhibited the lowest concentration of emitted gases compared to the other types of waste.