Green Remediation of Carbamazepine from Water Using Novel Magnetic Iron Modified Carbonized Baggasse: Kinetics, Equilibrium and Mechanistic Studies
Selly Jemutai-Kimosop *
Masinde Muliro University of Science and Technology, P.O.Box 190, Kakamega, Kenya
Veronica A. Okello
Machakos University, P.O.Box 136-90100, Machakos, Kenya
Francis Orata
Masinde Muliro University of Science and Technology, P.O.Box 190, Kakamega, Kenya
Zachary M. Getenga
Chuka University, P.O.Box 109-60400, Chuka, Kenya
Victor O. Shikuku
Maseno University, Private Bag, Maseno, Kenya
*Author to whom correspondence should be addressed.
Abstract
Baggasse derived biochar magnetically modified with iron (α-Fe2O3-CBG) was fabricated, characterized and applied as a low-cost adsorbent for the removal of carbamazepine (CBZ), a pharmaceutically active compound which has been reported as an emergent water contaminant. Characterization of the synthesized (α-Fe2O3-CBG) composite showed that iron was effectively impregnated onto the carbonized bagasse network. The composite was able to achieve 60.9 % CBZ removal within a period of 4 hours. The time-dependency adsorption data followed the pseudo-second order kinetic law while the intraparticle diffusion model indicated that pore diffusion is not the sole operative rate-determining mechanism with significant boundary layer effects. Freundlich model best explained the equilibrium sorption data. The adsorption extent was also strongly pH-dependent though adsorption mechanism is significantly driven by electrostatic interactions at lower pH. Furthermore, magnetic separation of the contaminant-laden adsorbent was successfully accomplished.
Keywords: Carbamazepine, adsorption, water, magnetic, iron-oxide