Development of Multi-Walled Carbon Nanotubes for Fe and Cu Ions Sorption from Pharmaceutical Wastewater

Abstract

Tnis study reports the preparation of nano-adsorbent from Multi-Walled Carbon nanotubes (MWCNTS) tor the removal Of Fe (II) and Cu (II) ions from pharmaceutical wastewater. Fe-Ni/Kaolin catalyst was prepared by wet impregnation method. The carbon nanotubes (CNTs) was synthesized in horizontal chemical vapour deposition (CVD) reactor using acetylene at 200 mL/min and nitrogen at 100 mL/min. The CVD reactor was operated at a temperature of 750 C for a period of 45 minutes. After which the as-synthesized CNTs was purified with 100 ml of 30 % HNO3 acid to give purified CNTs (P-CNTs) and functionalized with 100 mL of 20 % poly ethylene glycol (PEG) to give functionalized CNTs (F-CNTs). The catalyst and CNTs synthesized were characterized to determine its properties to determine its surface area, morphology/elemental composition and the internal morphology via Brunner Emmett Teller (BET), Scanning Electron Microscopy/ Energy Dispersion Spectroscopy (SEM/ED5) and High Resolution Transmission Electron Microscope (HRTEM) respectively. The SEM depicts the formation of long-continuous strand of CNTs formation while the HRTEM shows the hollow nature of the CNTs with multi-walls formation. T'he results obtained showed that F-CNTs produced has a larger surface area of 970.81 m2/g than P-CNTs The P-CNTs and F-CNTs were then applied for the removal of Fe (II) and Cu (II) from pharmaceutical wastewater. The effect of contact time, dosage of CNTS, and temperature for P-CNTs and F-CNTs were investigated. The optimum conditions for the adsorption of Fe and Cu ions from pharmaceutical wastewater were 60 minutes, 0.4g and 60 C respectively with %% removal of 74.37 for Fe and 79.65 for Cu ions. Freundlich models as well as pseudo-second order kinetic best fitted the adsorption of Fe and Cu from the pharmaceutical wastewater. The result revealed P-CNTs and F-CNTS were effective adsorbents for the removal of selected heavy metals from pharmaceutical wastewater.