Reduction of Cu+2 and Ni+2 ions from wastewater using mesoporous adsorbent: Effect of treated wastewater on corrosion behavior of steel pipelines

Abstract

LARGE amounts of highly heavy metals contaminated wastewater effluents are produced through the metal finishing and electroplating processes. In this study, mesoporous zeolite was prepared from Egyptian bentonite by alkali-hydrothermal method. The prepared zeolite was characterized by XRD technique showing the formation of crystalline phases corresponded to the zeolite structure. The adsorption performance of zeolite toward removal of copper (Cu+2) and nickel (Ni+2) ions was studied in relation to effect of contact time, concentrations of metal ions and the dose of adsorbent. The effect of Cu+2 and Ni+2 ions in treated wastewater on the corrosion behavior of steel pipelines was demonstrated. Elovich, Pseudo-first-order and Pseudo-second order kinetic models were applied. Kinetics models revealed that the adsorption of both Cu+2 and Ni+2 on zeolite was controlled by pseudo-second order kinetic and the equilibrium achieved at 90 min. Langmuir, Freundlich and Dubinin-Kaganer-Radushkevich isotherms were investigated and the results showed that the adsorption of both cations well-satisfied with Langmuir model. The free energy (E) was 10.66 and 8.772 kJ/mol for the adsorption of Cu+2 and Ni+2 ions, respectively, confirming that the adsorption mechanism is endothermic and proceed through ion-exchange. The effect of Cu+2 and Ni+2 on the corrosion behavior of steel pipelines revealed that the corrosion resistance of steel for treated and untreated water is almost the same.