scholarly journals Specifically designed amine functional group doped sludge biochar for inorganic and organic arsenic removal

2021 ◽  
Vol 31 (1) ◽  
Author(s):  
Chih-Kuei Chen ◽  
Nhat-Thien Nguyen ◽  
Thuy-Trang Le ◽  
Cong-Chinh Duong ◽  
Thi-Thanh Duong
Keyword(s):  
Surface Area ◽  
Photoelectron Spectroscopy ◽  
Density Functional ◽  
Arsenic Removal ◽  
Physical Adsorption ◽  
Dimethylarsinic Acid ◽  
Chemical Adsorption ◽  
Arsenic Adsorption ◽  
Organic Arsenic ◽  
Adsorption Energies

AbstractUsages of hospital sludge as a biochar adsorbent for wastewater treatment plants were investigated. Microwave carbonization was used to carbonize the sludge and then chemically activated with ZnCl2 to increase surface area and porosity. A newly designed amine functional group’s doped Sludge Biochar Carbon (SBC) presents effective inorganic arsenic (As (III)) and organic arsenic (Dimethylarsinic Acid, DMA) adsorption in water. The pore volume, pore size distribution and specific surface area were determined by performing nitrogen adsorption-desorption measurements. The Fourier Transform Infrared of the SBC was recorded to study the functional groups at room temperature. The composition of SBC was further determined by X-ray Photoelectron Spectroscopy. In order to understand the effect of amine functional complexes on arsenic adsorption, the adsorption mechanism of As (III) and DMA on SBC surfaces modified with amine functional complexes was studied using Density Functional Theory (DFT). DFT results showed that both physical and chemical adsorption of As (III) and DMA on SBC surfaces occurred. The participation of amine functional complexes greatly promoted the surface activity of SBC surface and its adsorption capacity on arsenic. The physical adsorption energies of As (III) and DMA on SBC surface with amine functional complexes were − 38.8 and − 32.4 kJ mol− 1, respectively. The chemical adsorption energies of As (III) and DMA on SBC surface with amine functional complexes were − 92.9 and − 98.5 kJ mol− 1, respectively.

Specifically Designed Amine Functional Group Doped Sludge Biochar for Inorganic and Organic Arsenic Removal

2020 ◽  
Author(s):  
Chih-Kuei Chen ◽  
Nhat-Thien Nguyen ◽  
Thuy-Trang Le ◽  
Cong-Chinh Duong ◽  
Thi-Thanh Duong
Keyword(s):  
Surface Area ◽  
Photoelectron Spectroscopy ◽  
Density Functional ◽  
Arsenic Removal ◽  
Physical Adsorption ◽  
Inorganic Arsenic ◽  
Chemical Adsorption ◽  
Arsenic Adsorption ◽  
Organic Arsenic ◽  
Adsorption Energies

Abstract Usages of hospital sludge as a biochar adsorbent for wastewater treatment plants were investigated. Microwave carbonization was used to carbonize the sludge and then chemically activated with ZnCl 2 to increase surface area and porosity. A newly designed amine functional group’s (DETA) doped sludge biochar carbon (SBC) presents effective inorganic arsenic (As(III), As 2 O 3 ) and organic arsenic (p-ASA, C 2 H 7 AsO 2 ) adsorption in water. The pore volume, pore size distribution and specific surface area were determined by performing nitrogen adsorption-desorption measurements (BET). The Fourier transform infrared (FTIR) of the SBC was recorded to study the functional groups at room temperature. The composition of SBC was further determined by X-ray photoelectron spectroscopy (XPS). In order to understand the effect of amine functional complexes on arsenic adsorption, the adsorption mechanism of As 2 O 3 and p-ASA on SBC surfaces modified with amine functional complexes was studied using density functional theory (DFT). Results showed that both physical and chemical adsorption of As 2 O 3 and p-ASA on SBC surfaces occurred. The participation of amine functional complexes greatly promoted the surface activity of SBC surface and its adsorption capacity on arsenic. The physical adsorption energies of As 2 O 3 and p-ASA on SBC surface with amine functional complexes were -38.4 and -32.8 KJ mol -1 , respectively. Other hand, the chemical adsorption energies of As 2 O 3 and p-ASA on SBC surface with amine functional complexes were -92.9 KJ mol -1 and -98.5 KJ mol -1 , respectively.

Adsorption Configurations of Iron Complexes on As(III) Adsorption Over Sludge Biochar Surface

2021 ◽  
Vol 21 (10) ◽  
pp. 5174-5180
Author(s):  
Chih-Kuei Chen ◽  
Nhat-Thien Nguyen ◽  
Cong-Chinh Duong ◽  
Thuy-Trang Le ◽  
Shiao-Shing Chen ◽  
...  
Keyword(s):  
Density Functional ◽  
Energy Savings ◽  
Wastewater Treatment Plants ◽  
Physical Adsorption ◽  
Inorganic Arsenic ◽  
Waste Recycling ◽  
Chemical Adsorption ◽  
Iron Metal ◽  
Adsorption Energies ◽  
The Impact

Waste recycling and reuse will result in significant material and energy savings. In this research, usage of hospital sludge as a biochar adsorbent for wastewater treatment plants was investigated. Microwave carbonization was used to carbonize the sludge and then chemically activated with ZnCl2to increase surface area and porosity. A newly designed iron metal doped sludge biochar carbon (SBC) has effective adsorption of inorganic arsenic (As(III), As2O3) in water. The findings clearly demonstrate the viability and utility of using hospital sludge as a source of carbon to generate SBC. The adsorption mechanism of As(III) on SBC’s iron-metal-modified surface has been studied using density functional theory (DFT) to understand the impact of functional complexes on adsorption As(III). Tests showed physical as well as chemical adsorption of As(III) on Fe-SBC surface. Fe’s involvement in functional complexes greatly fostered SBC surface activity and it’s As(III) adsorption ability. The physical adsorption energies of As(III) with Fe functional complexes on the SBC surface were −42.3 KJ mol−1. Other hand, the chemical adsorption energies of As(III) on Fe-SBC surface was −325.5 KJ mol−1. As(III) is capable of interacting in a bidentate fashion with the dopants through the protonated oxygen atoms and this conformation of the cyclic structure is higher in the adsorption energy than the others.

Microstructure and Oxygen Functional Groups on Modified Liquefied Wooden Activated Carbon Fibers with Hydrogen Peroxide

2013 ◽  
Vol 433-435 ◽  
pp. 2003-2007 ◽  
Author(s):  
Wei Gao ◽  
Gaungjie Zhao
Keyword(s):  
Hydrogen Peroxide ◽  
Activated Carbon ◽  
Surface Area ◽  
Functional Groups ◽  
Carbon Fibers ◽  
Photoelectron Spectroscopy ◽  
Density Functional ◽  
Activated Carbon Fibers ◽  
Average Pore ◽  
Oxygen Functional Groups

The aim of this study is to investigate changes in microstructure and oxygen functional groups of liquefied wood activated carbon fibers using density functional theory, FTIR, X-ray photoelectron spectroscopy. Samples were immersed with hydrogen peroxide (H2O2) at three concentrations (15, 20, and 25 wt%), three temperatures (90, 70, and 50 °C) for three periods of time (1, 2, and 3 h). The results reveals that the pores average radius narrow, and micropores turn into mesopores or macropores with the increasing process, which brings about the surface area of treated samples decrease. Numerous oxygen functional groups are observed in the treated samples, and the ratios of oxygen and carbon increase from 3.2% before treated to 14.7% with H2O2 modification. The results confirm that the average pore radius and surface area decrease during treatment due to concentration and temperature. What is more, oxygen functional groups increase significantly with increasing treatment concentration.

FIRST-PRINCIPLES STUDY OF THE ADSORPTION AND DIFFUSION OF O2 ON A Si(001) SURFACE

2011 ◽  
Vol 18 (06) ◽  
pp. 315-321
Author(s):  
CHUN YANG ◽  
CHONG YANG ◽  
PING HUANG ◽  
XIAO QIN LIANG
Keyword(s):  
First Principles ◽  
Density Functional ◽  
Early Stage ◽  
Physical Adsorption ◽  
Stable State ◽  
Surface Oxidation ◽  
Chemical Adsorption ◽  
Bridge Structure ◽  
Oxygen Bridge ◽  
And Diffusion

We apply a first-principles molecular-dynamics method based on the density functional theory to calculate several initial configurations of an O2 molecule adsorbed on a Si(001) surface. The bonding processing, adsorption energy, dynamic track, and diffusion coefficient are investigated. The results indicate that the adsorption process may be divided into four stages: physical adsorption, chemical adsorption early stage, chemical adsorption late stage, and the superficial stable state. The Si=O structure, the Si–O–Si surface oxygen-bridge structure, and the Si–O–Si oxygen-bridge structure where oxygen atoms are inserted into the backbonds between the surface and the second layer of silicon atoms in the stable adsorption structures, are beneficial to the formation of the silica tetrahedral structure. We conclude that the remarkable difference between the diffusion coefficients during the physical adsorption stage leads to different diffusion paths, which results in the formation of two concomitant stable structures in the early process of silicon surface oxidation.

Theoretical Investigation of the Adsorption of Nh3 on B-Doped Graphene

2011 ◽  
Vol 474-476 ◽  
pp. 720-724
Author(s):  
Dong Mei Bi ◽  
Liang Qiao ◽  
Xiao Ying Hu ◽  
Wen Zhi
Keyword(s):  
Charge Transfer ◽  
Electronic Structures ◽  
Density Functional ◽  
Physical Adsorption ◽  
Adsorption Properties ◽  
Charge Redistribution ◽  
Geometrical Structures ◽  
Functional Theory ◽  
Doped Graphene ◽  
Adsorption Energies

The geometrical structures, the electronic structures, and the NH3adsorption properties of pure and B-doped graphene have been investigated using density-functional theory. The density of states (DOS) of pure and B-doped graphene, the adsorption configurations and the adsorption energies of NH3adsorbed on pure and B-doped graphene, and the charge transfer between NH3and B-doped graphene have been calculated in details. The results indicate that boron doping can enhance the DOS at the Fermi level and slightly enhance the physical adsorption of NH3on the surface of graphene. Furthermore, the doping of boron can result in the charge redistribution of graphene, which can induce the charge transfer between NH3and graphene and change the transport properties of graphene.

scholarly journals Fe-FeS2 adsorbent prepared with iron powder and pyrite by facile ball milling and its application for arsenic removal

2017 ◽  
Vol 76 (1) ◽  
pp. 192-200 ◽  
Author(s):  
Xiaobo Min ◽  
Yangwenjun Li ◽  
Yong Ke ◽  
Meiqing Shi ◽  
Liyuan Chai ◽  
...  
Keyword(s):  
Adsorption Capacity ◽  
Ball Milling ◽  
Photoelectron Spectroscopy ◽  
Arsenic Removal ◽  
Molar Ratio ◽  
Arsenic Adsorption ◽  
Arsenic Uptake ◽  
X Ray ◽  
Before And After ◽  
High Arsenic

Arsenic is one of the major pollutants and a worldwide concern because of its toxicity and chronic effects on human health. An adsorbent of Fe-FeS2 mixture for effective arsenic removal was successfully prepared by mechanical ball milling. The products before and after arsenic adsorption were characterized with scanning electron microscopy, X-ray diffraction, Fourier transform infrared spectroscopy, and X-ray photoelectron spectroscopy. The adsorbent shows high arsenic removal efficiency when molar ratio of iron to pyrite is 5:5. The experimental data of As(III) adsorption are fitted well with the Langmuir isotherm model with a maximal adsorption capacity of 101.123 mg/g. And As(V) data were described perfectly by the Freundlich model with a maximal adsorption capacity of 58.341 L/mg. As(III) is partial oxidized to As(V) during the adsorption process. High arsenic uptake capability and cost-effectiveness of waste make it potentially attractive for arsenic removal.

scholarly journals Bastnaesite, Barite, and Calcite Flotation Behaviors with Salicylhydroxamic Acid as the Collector

Minerals ◽  
2020 ◽  
Vol 10 (3) ◽  
pp. 282 ◽  
Author(s):  
Wenliang Xiong ◽  
Jie Deng ◽  
Kaile Zhao ◽  
Weiqing Wang ◽  
Yanhong Wang ◽  
...  
Keyword(s):  
Zeta Potential ◽  
Photoelectron Spectroscopy ◽  
Physical Adsorption ◽  
Solution Chemistry ◽  
Chemical Adsorption ◽  
Salicylhydroxamic Acid ◽  
X Ray ◽  
Ft Ir ◽  
Bastnaesite Flotation ◽  
Flotation Behavior

The flotation of bastnaesite, as a major mineral source of rare earth elements, attracting much attention in the mineral processing field, is challenging owing to the natural flotability of calcium-bearing minerals. To promote the application of flotation, we systematically investigated the flotation behavior of bastnaesite, barite, and calcite, with salicylhydroxamic acid (SHA) as the collector through micro-flotation experiments, zeta-potential measurements, Fourier transform infrared (FT-IR) analyses, X-ray photoelectron spectroscopy (XPS) analyses, and solution chemistry analyses. Micro-flotation experiments confirm that the flotability of bastnaesite is high at pH 6.5–8.5, while calcite floats at pH 8.0–9.5, and barite has little flotation response. The results of FT-IR, XPS, and zeta-potential measurements indicate that there is chemical adsorption of SHA on the bastnaesite surface, and physical adsorption also occurs. However, as for barite and calcite, there is only physical adsorption of SHA on the surfaces. The solution chemistry results show that SHA anions can interact with RE3+, REOH2+, and RE(OH)2+ on bastnaesite surfaces in aqueous suspensions, resulting in bastnaesite flotation.

Optimisation of sugar cane activated carbon for arsenic(V) and arsenic(III) removal from water

2013 ◽  
Vol 13 (2) ◽  
pp. 319-327
Author(s):  
M. Velasco-Perez ◽  
K. M. Hiscock
Keyword(s):  
Activated Carbon ◽  
Surface Area ◽  
Sugar Cane ◽  
Arsenic Removal ◽  
Low Cost ◽  
Strong Positive Correlation ◽  
Treatment Technology ◽  
Arsenic Adsorption ◽  
Activation Temperature ◽  
Strong Negative Correlation

This paper addresses the development of low-cost adsorbents for removal of arsenic from water in support of mitigation programmes in low and middle income countries. Activated carbon (AC) is a well established water treatment technology, but has high cost and low selectivity in respect of arsenic. AC made from agricultural by-products is a low-cost alternative to coal-based AC. In this study, the preparation parameters of sugar-cane activated carbon (SCAC) were optimised for arsenic(V) and arsenic(III) adsorption. The effect of preparation parameters on arsenic removal was investigated with a 23 factorial experiment. SCAC was characterised by the pH of zero charge, surface area, pore width distribution, particle size distribution and imaging under scanning electron microscopy. Activation temperature (AT) has a profound effect on arsenic adsorption; arsenic(V) adsorption increased from 2.8% at an AT of 873 K to 87.6% at an AT of 1,173 K. The percentage of arsenic removal from water has a strong positive correlation with surface area, and a strong negative correlation with micropore/pore volume ratio and the percentage in volume of particles with a size of 60–2,000 μm. In conclusion, this research shows that low-cost AC can be manufactured for removal of target pollutants, such as arsenic, from water.

scholarly journals Lanthanum Exchanged Keggin Structured Heteropoly Compounds for Biodiesel Production

Catalysts ◽  
2019 ◽  
Vol 9 (12) ◽  
pp. 979 ◽  
Author(s):  
Badriah Al-Shammari ◽  
Qana A. Alsulami ◽  
Katabathini Narasimharao
Keyword(s):  
High Activity ◽  
Surface Area ◽  
Photoelectron Spectroscopy ◽  
Physical Adsorption ◽  
Acid Sites ◽  
Biodiesel Production ◽  
One Pot ◽  
Exchange Method ◽  
X Ray ◽  
Basic Sites

La-exchanged 12-tungstophosphoric acid (LaxTPA) and 12-molybdophosphoric acid (LaxMPA) salts (x = 0.25, 0.50, 0.75 and 1.00) were prepared via an ion exchange method. The physico-chemical characteristics of the materials were analyzed by using elemental analysis, X-ray diffraction (XRD), Fourier transformed infrared (FT-IR) spectroscopy, scanning electron microscopy (SEM), N2-physical adsorption, X-ray photoelectron spectroscopy (XPS), and acidity-basicity measurements. The results indicated that La was introduced into the secondary structure of heteropolyacid (HPA) and have not influenced the primary structure, which effectively improved the surface area and pore size. Acidity-basicity studies indicated that incorporation of La resulted in a decrease in the number of acid sites and an increase in the number of basic sites. The catalytic activity of samples was studied in transesterification of glyceryl tributyrate with methanol and LaxTPA samples which exhibited high activity compared to LaxMPA samples due to having more active basic sites and a larger surface area. Calcined LaxTPA samples showed excellent stability, outstanding recyclability, and high activity for one pot transesterification and esterification processes. This outcome was attributed to the presence of balanced acidic and basic sites.

scholarly journals Novel Design of Amine and Metal Hydroxide Functional Group Modified Onto Sludge Biochar for Arsenic Removal

2021 ◽  
Author(s):  
Chih-Kuei Chen ◽  
Nhat-Thien Nguyen ◽  
Thuy-Trang Le ◽  
Cong-Chinh Duong ◽  
Cong-Nguyen Nguyen ◽  
...  
Keyword(s):  
Density Functional ◽  
Arsenic Removal ◽  
Operating Cost ◽  
Adsorption Efficiency ◽  
Arsenic Adsorption ◽  
Adsorption Method ◽  
Simple Method ◽  
Electrostatic Adsorption ◽  
Operation Conditions ◽  
Oxidation Reduction

Abstract Among the arsenic removal technologies, the adsorption method is found to be an efficient, inexpensive and simple method with obvious advantages and application value for arsenic removal in water. While, each method has its limitations, the traditional adsorption method used for arsenic removal due to its high operating cost and low adsorption efficiency. Consequently, this study explicitly designed sludge biochar (SB) adsorbed for arsenic removal with lower operation costs and higher adsorption efficiency properties. Generally, biochar only relies on micropores for pollutant adsorption, but physical adsorption is not highly efficient for arsenic removal. Therefore, in order to improve the removal efficiency of arsenic by SB, diethylenetriamine (DETA) and FeCl3 were used in this study to modify the surface of SB by an immersion method. The modified SB has not only pore adsorption characteristics but also electrostatic adsorption, oxidation-reduction and complexation characteristics. The objectives of this research are to obtain optimum operation conditions by assessing the effect of different Fe content, pH and initial concentration on adsorbing arsenic. The arsenic adsorption mechanism on SB was studied using Density Functional Theory (DFT) to understand the functional effect on arsenic adsorption. Results showed the presence of amine and iron oxyhydroxides functional greatly promoted SB surface activity and its arsenic adsorption potential. DFT model result is the same as the result of arsenic adsorption performance with the high adsorption energy. The reaction mechanism is divided into four pathways, including oxidation-reduction, complexation, electrostatic adsorption and pore adsorption.

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