Equilibrium and Kinetic of ultrasound-assisted adsorption of Chromium (VI) ion from electroplating wastewater using melon seed husk activated carbon

Abstract

This study was focused on the removal of Cr(VI) ions from electroplating wastewater by ultrasound-assisted adsorption onto activated carbon obtained from melon seed husk. The activated carbon was produced by carbonization of crushed melon seed husk at a temperature of 500 °C for 15 min and further activation using 1.0 M concentration of potassium chloride (KCl) at a temperature of 500 °C for 90 min in a muffle furnace. The obtained adsorption isotherm data were better fitted to the Langmuir model than Freundlich model for adsorption both in the presence and absence of ultrasound (US). The adsorbent maximum adsorption capacity for Cr(VI) ion obtained from the Langmuir isotherms, were 5.059 mg/g and 2.031 mg/g both in the presence of ultrasound and its absence, respectively. The adsorption process in the presence and absence of ultrasound obeyed the pseudo-second-order kinetics. The SEM image of activated carbon before adsorption of metal ion revealed that the surface of activated carbon contains pores with different sizes and shapes, and also showed a significant change on the surface of activated carbon after interaction with Cr(VI) ions.

Keywords

• carbonization
• activated carbon
• melon seed husk
• ultrasound-assisted adsorption