Methylene blue magnetic adsorption separation process from aqueous solution using corn cob

Abstract

Climate change and growing human, industrial and agricultural activities, in view of the growing population, constitute a threat to water resources due to all pollutant discharges that are not very biodegradable and/or toxic. Drinking water is therefore, becoming the central concern of public opinion and leaders. It therefore appears important to reduce polluting emissions at the level of effluents as much as possible. The adsorption of methylene blue (MB) on the powder of modified and magnetized corn cobs (MCC) was studied. This study aims, not only to recover this polluting waste, but also to bypass heavy separation techniques such as centrifugation, sedimentation and filtration. The prepared biosorbent was characterized by XRD and SEM. Parameters influencing the adsorption process such as contact time, adsorbent dosage, pH and temperature were determined. The kinetic study indicated that the adsorption phenomenon fits the pseudo-second-order model better. The influence of temperature on adsorption allowed the determination of thermodynamic parameters (ΔG°, ΔH° and ΔS°). The MB adsorption process by the magnetic adsorbent obeys the single-layer Langmuir model. A maximum adsorption capacity of MCC equal to 13.23 mg/g was obtained. In view of the results obtained, MCC appears to be a very favorable adsorbent for MB removal from aqueous medium.

Keywords

• Corn cobs
• Magnetic biosorbent
• Methylene blue
• Adsorption
• Modeling