Using Electrocoagulation-Electroflotation Technique to Treat Textile Wastewater

摘要

In EC, coagulants are delivered in situ using the corrosion of sacrificial anodes when a DC voltage is applied. Simultaneously, electrolytic gases (H_2) are generated at the cathode. Aluminum and iron materials are usually used as anodes, the dissolution of which produces hydroxides and polymeric hydroxides. These coagulants are able to destabilize colloidal suspensions and emulsions, to adsorb, neutralize or precipitate dissolved polluting species, and finally to form flocs that can be removed either by settling or flotation. In this work we have studied the influence of the operating parameters of EC-EFsuch as current density (j), water pH and conductivity (κ) on the elimination of a red dye used in the textile industry. According to the results obtained, it appears that the influence of the current density on the abatement of turbidity, the color and the COD is very significant. A rate of abatement of about 77.25% for turbidity 86.55% for the color and 78.5% for the COD was observed, when the initial concentration of the red dye C_0 = 100 mg/L, current density j= 150 A/m~2, conductivity κ=3.56 mS/cm, the inlet flow rate Q=0.15 L min~(-1), the processing time t = 40 min and the initial pH = 7.65. A model expressing the reduction of COD according to aluminum consumption, was proposed and translated in a satisfactory way the results obtained in experiments.