Removal of uranium and associated contaminants from aqueous solutions using functional carbon nanotubes-sodium alginate conjugates

Abstract

Synthesis of hydrophilic/hydrophobic beads from functional carbon nanotubes (CNTs) conjugated with sodium alginate was investigated. Glutaraldehyde was used as a coupling agent and Ca2+ as a crosslinking agent. The formed conjugate comprises two-dimensional sheets of sodium alginate bounded to long tufts of functional CNT tails of micro-size geometry. Detailed characterization of the conjugates was performed using thermogravimetric analysis (TGA) and its first derivative (DTG), Fourier transform infrared (FTIR), and scanning electron microscope (SEM) techniques. Different ratios of the conjugate were successfully prepared and used as biodegradable environmentally friendly sorbents. Removal of U6+, V3+, Cr3+, Mo3+, Pb2+, Mn2+, Cu2+, Ti4+ and Ni2+ from aqueous solutions using the synthesized biosorbent was experimentally demonstrated. Maximum metal uptake of 53 mg/g was achieved using the % Functional CNTs = 33 sample.