Content area
Abstract
The adsorption of hexadecyltrimethylammonium (HDTMA) on graphene oxide (GO) was investigated to probe the molecular interaction of HDTMA adsorbed GO (GO-HDTMA) with nitrates. Physicochemical techniques including scanning electron microscope (SEM), transmission electron microscope (TEM), fourier transform infrared spectrometer (FTIR), Brunauer–Emmett–Teller (BET), X-ray diffraction (XRD), and Raman spectroscopy were used to characterize GO-HDTMA, and the effect of GO functionalization on nitrates adsorption was examined. Unmodified physical GO exhibited the weakest adsorption capability (~1.0 mmol g−1). However, nitrate adsorption was markedly enhanced by chemical GO modified with 10 mmol HDTMA (GO-HDTMA-10 mM). Which can be attributed to the various functional groups on GO and increased active sites inducing HDTMA longer chain and higher carbon content. The nitrates adsorption process attain equilibrium in 3 h with maximum adsorption density of 16 mM g−1. HDTMA adsorption was enhanced by pH changes, with pH 6 exhibiting the highest adsorption. It was found that the negative charges on GO results in the retention of HDTMA, while the hydrophobic phase created by the alkyl chain in HDTMA enables the adsorption of nitrates. The X-ray photoelectron spectrometer (XPS) analysis revealed a chemical shift caused by the adsorption of HDTMA and nitrates on the surface of GO. The reusability of the adsorbent was evaluated over four consecutive cycles. GO-HDTMA showed good removal efficiency for up to third regeneration cycles. Results reveal that the nitrates can be adsorbed more efficiently by modifying the HDTMA’s surface coverage on GO.
Details
Nitrate removal;
Scanning electron microscopy;
pH;
Water treatment;
Clean technology;
Reverse osmosis;
X-ray diffraction;
Fourier transforms;
Raman spectroscopy;
Functional groups;
Graphene;
Molecular interactions;
Nitrates;
Radiation;
Pollutants;
Adsorbents;
Energy efficiency;
Adsorption;
Infrared spectrometers;
Nutrient removal;
Photoelectrons;
Aqueous solutions;
Chemical equilibrium;
X ray photoelectron spectroscopy;
Electron microscopes;
X rays;
Morphology;
X-rays;
Hydrophobicity;
FTIR spectrometers;
Energy
; Lin, Po-Hsun 3 ; Chang, Jih-Hsing 4 ; Ku-Fan, Chen 5 ; Wang, TsingHai 6 ; Choi, Soohoon 7 ; Shan-Yi, Shen 8 ; Zhou, Shuo-Xuan 1 ; Cheng-Yu, Ho 1 ; Jenn Fang Su 9
; Chen, Ching-Lung 10
; Bhuyar, Prakash 11
1 Department of Safety, Health and Environmental Engineering Ming Chi University of Technology New Taipei City 24301 Taiwan
2 Center for Environmental Sustainability and Human Health Ming Chi University of Technology New Taipei City 24301 Taiwan
3 Graduate Institute of Environmental Engineering National Central University Taoyuan City 32001 Taiwan
4 Department of Environmental Engineering and Management Chaoyang University of Technology Taichung 413310 Taiwan
5 Department of Civil Engineering National Chi Nan University Puli Nantou 545301 Taiwan
6 Department of Chemical Engineering and Materials Science Yuan Ze University Zhongli 32003 Taiwan
7 Department of Environmental Engineering Chungnam National University 99 Daehak-ro, Daejeon Yuseong-gu 34134 Republic of Korea
8 Department of Environmental Engineering Da-Yeh University Dacun Changhua 515006 Taiwan
9 Department of Chemical and Materials Engineering Chang Gung University Taoyuan 33302 Taiwan; Division of Hematology and Oncology Department of Internal Medicine Chang Gung Memorial Hospital at Linkou Taoyuan 33302 Taiwan; Center for Sustainability and Energy Technologies Chang Gung University Taoyuan 33302 Taiwan
10 Department of Safety, Health and Environmental Engineering Ming Chi University of Technology New Taipei City 24301 Taiwan; Center for Environmental Sustainability and Human Health Ming Chi University of Technology New Taipei City 24301 Taiwan; Center for Sustainability and Energy Technologies Chang Gung University Taoyuan 33302 Taiwan
11 International Industry and Agriculture Innovation Research Center (IIAR) International College Maejo University Chiang Mai 50290 Thailand