ao0c00166_si_001.pdf (211.05 kB)
Removal of Hazardous Contaminants from Water by Natural and Zwitterionic Surfactant-modified Clay
journal contribution
posted on 2020-03-20, 08:40 authored by Hany H. Abdel Ghafar, Emad K. Radwan, Shaimaa T. El-WakeelIn this study, natural clay (NC)
was collected from Saudi Arabia
and modified by cocamidopropyl betaine (CAPB) at different conditions
(CAPB concentration, reaction time, and reaction temperature). NC
and modified clay (CAPB-NC) were characterized using X-ray diffraction,
thermogravimetric analysis, Fourier transform infrared spectroscopy,
field-emission scanning electron microscopy, and N2 adsorption
at 77 K. The adsorption efficiency of NC and CAPB-NC toward Pb2+ and reactive yellow 160 dye (RY160) was evaluated. The adsorption
process was optimized in terms of solution initial pH and adsorbent
dosage. Finally, the adsorption kinetics and isotherms were studied.
The results indicated that NC consists of agglomerated nonporous particles
composed of quartz and kaolinite. CAPB modification reduced the specific
surface area and introduced new functional groups by adsorbing on
the NC surface. The concentration of CAPB affects the adsorption of
RY160 tremendously; the optimum concentration was 2 times the cation
exchange capacity of NC. The equilibrium adsorption capacity of CAPB-NC
toward RY160 was about 6 times that of NC and was similar for Pb2+. The adsorption process followed the pseudo-second-order
kinetics for both adsorptive. RY160 adsorption on CAPB-NC occurs via
multilayer formation while Pb2+ adsorption on NC occurs
via monolayer formation..