TITLE:
Remediation of Heavy Metal (Cd, Cr, Cu, Co, and Ni) Ions from Kaolinite Clay Using Molecular Micelles Chelators and D-Optimum Experimental Design
AUTHORS:
Sayo O. Fakayode, Ashley M. Taylor, Maya McCoy, Sri Lanka Owen, Whitney E. Stapleton, Carmen Grady, David A. Pollard
KEYWORDS:
Heavy Metal Ion Remediation; Molecular Micelles Chelator; D-Optimum Experimental Design; Kaolinite Clay
JOURNAL NAME:
Journal of Environmental Protection,
Vol.4 No.8,
August
5,
2013
ABSTRACT: This study investigated the potential
utility of poly (sodium N-undecanoyl-L-leucyl-valinate) (poly-L-SULV), poly (sodium N-undecanoyl-L-leucyl-alanate) (poly-L-SULA), and poly (sodium N-undecanoyl-glycinate)
(poly-SUG) molecular micelles (MMs) as chelators for heavy metal (Cd,
Cr, Cu, Co, and Ni) ion remediation of kaolinite clay using D-optimum
experimental design. D-optimum experimental design was employed to
simultaneously investigate the influence of design variables such as the buffer
pH, chelator concentration, and centrifuge speed to evaluate the optimum
conditions and to reduce the time and cost of metal ion remediation. The
partition coefficients of the metal ion concentrations between the kaolinite
clay and chelator equilibrium were also evaluated. In addition, the influence
of metal ion concentrations on the remediation capability of the chelators was
evaluated by conducting remediation studies at four different (10 ppm, 40 ppm,
60 ppm, and 80 ppm) metal ion concentrations. In general, the results of the
remediation efficiency and partition coefficients obtained in this study are
highly metal ion dependent and also dependent upon the chelator used for the
remediation. Specifically, the remediation efficiency of the molecular micelles
was found to be comparable to or better than the corresponding remediation efficiency obtained when SDS
or EDTA was used for the remediation. However, at optimum conditions, poly-SULV
and poly-L-SULA molecular micelle chelators demonstrated superior remediation
efficiencies for Cr, with remediation efficiency of 99.9 ± 8.7% and 99.1 ± 0.7%,
respectively.