Industrial Wastewater Treatment Using Eco-Friendly Techniques

Abstract

This work investigates the treatment of industrial wastewater namely: “Cooling tower blowdown water” using an eco-friendly technique (e.g. Electrocoagulation (EC)). The electrocoagulation system is characterized by the fact that the water to be treated passes through an electrochemical cell with aluminum, iron, magnesium, and zinc plates. When an electrical current is applied to an amperage that allows an optimum current density to produce the aluminum required to form metal hydroxides. Real samples have been collected from the urea fertilizer plant (Helwan Fertilizer Company) in Egypt. Initially, a batch mode was used to optimize the design parameters: type of the electrode, inter-electrode distance, current density, and electrolysis time. The optimal parameters were found to be at a current density of 14.29 mA/cm2; inter-electrode distance of 1.0 cm and electrolysis time 120 min with an aluminum electrode. The performance of the continuous up-flow reactor with these parameters was satisfactory, the maximum removal efficiency of hardness ions reached to 80.42 % and silica to 99.74% at a flow rate of 41.67 mL/min with an operating cost of 0.49 US$/m3 treated water using aluminum electrodes. SEM-EDX, XRD, FTIR, and SVI, which investigates the surface morphology, structure crystalline type, functional groups and settling ability of EC sludge. EDX exposed the existence of hardness ions and silica in the EC sludge which confirmed the removal of these scale species from cooling tower blowdown water. The conclusion can be drawn that electrocoagulation may successfully be applied with Al-electrode to treat cooling tower blowdown water for its reuse.