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.

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.

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.

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.

EMERGING TRENDS IN ELECTRICAL ENERGY USAGE AT CANADIAN (ONTARIO) MUNICIPAL WASTEWATER TREATMENT FACILITIES AND STRATEGIES FOR IMPROVING ENERGY EFFICIENCY

1994 ◽  
Vol 30 (4) ◽  
pp. 17-23 ◽  
Author(s):  
B. Evans ◽  
P. Laughton
Keyword(s):  
Wastewater Treatment ◽  
Municipal Wastewater ◽  
Energy Savings ◽  
Wastewater Treatment Plants ◽  
Sewage Treatment ◽  
Target Area ◽  
Municipal Wastewater Treatment ◽  
Sewage Treatment Plants ◽  
The Impact ◽  
Ontario Hydro

The province of Ontario is Canada's most populous province with over 8 million residents out of a total population of 27 million. The Province is situated in the eastern portion of North America and stretches from 41°N to 50° N. All the Great Lakes fall within Ontario's boundaries and the Province is estimated to have over 280,000 lakes. The area along Lake Ontario is home to 5 million of the residents who are serviced by 11 large sewage treatment plants. The remaining 403 treatment plants are scattered throughout the province. with an average size of 20 000 m3/d. Ontario Hydro commissioned a study of the wastewater treatment plants to identify the main power users at the various types of sewage treatment plants, as well as potential areas within each plant where significant energy savings could be generated. By using this information, Ontario Hydro hoped to assess the potential to reduce the load and identify any electrical efficiency improvements, fuel switching and load shifting opportunities that may exist as well as the impact of environmental regulations on power saving initiatives. It was found that several major opportunities existed. These included:■ that up to 25% of power currently used can be reduced by introducing energy efficient measures■ of all the unit operations in wastewater treatment plants, aeration accounts for 42% of the power usage, influent and effluent pumping - 20%, and dewatering - 6%. Of this influent and effluent pumping, specifically influent represented the best target area as significant aeration system upgrade had already taken place.

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 Combinations of Freeze-Dried Amorphous Vardenafil Hydrochloride with Saccharides as A Way to Enhance Dissolution Rate and Permeability

2021 ◽  
Vol 14 (5) ◽  
pp. 453
Author(s):  
Gabriela Wiergowska ◽  
Dominika Ludowicz ◽  
Kamil Wdowiak ◽  
Andrzej Miklaszewski ◽  
Kornelia Lewandowska ◽  
...  
Keyword(s):  
Physicochemical Properties ◽  
Density Functional ◽  
Hydroxypropyl Methylcellulose ◽  
Fold Increase ◽  
Crystalline Form ◽  
Amorphous Form ◽  
Freeze Dried ◽  
Apparent Solubility ◽  
Gastrointestinal Epithelium ◽  
The Impact

To improve physicochemical properties of vardenafil hydrochloride (VAR), its amorphous form and combinations with excipients—hydroxypropyl methylcellulose (HPMC) and β-cyclodextrin (β-CD)—were prepared. The impact of the modification on physicochemical properties was estimated by comparing amorphous mixtures of VAR to their crystalline form. The amorphous form of VAR was obtained as a result of the freeze-drying process. Confirmation of the identity of the amorphous dispersion of VAR was obtained through the use of comprehensive analysis techniques—X-ray powder diffraction (PXRD) and differential scanning calorimetry (DSC), supported by FT-IR (Fourier-transform infrared spectroscopy) coupled with density functional theory (DFT) calculations. The amorphous mixtures of VAR increased its apparent solubility compared to the crystalline form. Moreover, a nearly 1.3-fold increase of amorphous VAR permeability through membranes simulating gastrointestinal epithelium as a consequence of the changes of apparent solubility (Papp crystalline VAR = 6.83 × 10−6 cm/s vs. Papp amorphous VAR = 8.75 × 10−6 cm/s) was observed, especially for its combinations with β-CD in the ratio of 1:5—more than 1.5-fold increase (Papp amorphous VAR = 8.75 × 10−6 cm/s vs. Papp amorphous VAR:β-CD 1:5 = 13.43 × 10−6 cm/s). The stability of the amorphous VAR was confirmed for 7 months. The HPMC and β-CD are effective modifiers of its apparent solubility and permeation through membranes simulating gastrointestinal epithelium, suggesting a possibility of a stronger pharmacological effect.

scholarly journals An Evaluation of the Impact of the Amount of Potassium Hydroxide on the Porous Structure Development of Activated Carbons

Materials ◽  
2021 ◽  
Vol 14 (8) ◽  
pp. 2045
Author(s):  
Mirosław Kwiatkowski ◽  
Elżbieta Broniek ◽  
Vanessa Fierro ◽  
Alain Celzard
Keyword(s):  
Density Functional Theory ◽  
Porous Structure ◽  
Potassium Hydroxide ◽  
Density Functional ◽  
Activated Carbons ◽  
Chemical Activation ◽  
Appropriate Technology ◽  
Functional Theory ◽  
Homogeneous Surface ◽  
The Impact

This paper presents the results of an evaluation of the impact of the amount of potassium hydroxide on the obtained porous structure of the activated carbons derived from the shells of pistachios, hazelnuts, and pecans by carbonization and subsequent chemical activation with potassium hydroxide by different adsorption methods: Brunauer–Emmett–Teller, Dubinin–Raduskevich, the new numerical clustering-based adsorption analysis, Quenched Solid Density Functional Theory, and 2D-Non-linear Density Functional Theory for Heterogeneous Surfaces, applied to nitrogen adsorption isotherms at −196 °C. Based on the conducted research, a significant potential for the production of activated carbons from waste materials, such as nut shells, has been demonstrated. All the activated carbons obtained in the present study at the activator/char mass ratio R = 4 exhibited the most developed porous structure, and thus very good adsorption properties. However, activated carbons obtained from pecan shells deserve special attention, as they were characterized by the most homogeneous surface among all the samples analyzed, i.e., by a very desirable feature in most adsorption processes. The paper demonstrates the necessity of using different methods to analyze the porous structure of activated carbons in order to obtain a complete picture of the studied texture. This is because only a full spectrum of information allows for correctly selecting the appropriate technology and conditions for the production of activated carbons dedicated to specific industrial applications. As shown in this work, relying only on the simplest methods of adsorption isotherm analysis can lead to erroneous conclusions due to lack of complete information on the analyzed porous structure. This work thus also explains how and why the usual characterizations of the porous structure of activated carbons derived from lignocellulosic biomass should not be taken at face value. On the contrary, it is advisable to cross reference several models to get a precise idea of the adsorbent properties of these materials, and therefore to propose the most suitable production technology, as well as the conditions of the preparation process.

scholarly journals Energy Performance Assessment of Innovative Building Solutions Coming from Construction and Demolition Waste Materials

Materials ◽  
2021 ◽  
Vol 14 (5) ◽  
pp. 1226
Author(s):  
Beatriz Fraga-De Cal ◽  
Antonio Garrido-Marijuan ◽  
Olaia Eguiarte ◽  
Beñat Arregi ◽  
Ander Romero-Amorrortu ◽  
...  
Keyword(s):  
Thermal Insulation ◽  
Energy Demand ◽  
Energy Savings ◽  
Flow Analysis ◽  
Weather Conditions ◽  
Energy Performance ◽  
Construction And Demolition Waste ◽  
The European Union ◽  
Demolition Waste ◽  
The Impact

Prefabricated solutions incorporating thermal insulation are increasingly adopted as an energy conservation measure for building renovation. The InnoWEE European project developed three technologies from Construction and Demolition Waste (CDW) materials through a manufacturing process that supports the circular economy strategy of the European Union. Two of them consisted of geopolymer panels incorporated into an External Thermal Insulation Composite System (ETICS) and a ventilated façade. This study evaluates their thermal performance by means of monitoring data from three pilot case studies in Greece, Italy, and Romania, and calibrated building simulation models enabling the reliable prediction of energy savings in different climates and use scenarios. Results showed a reduction in energy demand for all demo buildings, with annual energy savings up to 25% after placing the novel insulation solutions. However, savings are highly dependent on weather conditions since the panels affect cooling and heating loads differently. Finally, a parametric assessment is performed to assess the impact of insulation thickness through an energy performance prediction and a cash flow analysis.

scholarly journals Impact of Hotel Guests’ Trends to Recycle Food Waste to Obtain Bioenergy

2021 ◽  
Vol 13 (6) ◽  
pp. 3094
Author(s):  
Wagih Salama ◽  
Essam Abdelsalam
Keyword(s):  
Food Waste ◽  
Alternative Energy ◽  
Waste Recycling ◽  
Environmental Preservation ◽  
Alternative Energy Sources ◽  
Effective Role ◽  
Food Waste Recycling ◽  
Intentions To Participate ◽  
Hotel Managers ◽  
The Impact

Hotels face many issues related to food waste management, which is considered a serious environmental and socioeconomic issue in the 21st century. The improper disposal of food waste causes greenhouse gases emissions, consequently badly affecting the environment. This research aims to measure the impact of customer trends in changing the pattern of food waste disposal and recycling into bioenergy relating to hotel purposes and contributing to reducing hotel energy costs in Egypt. Two survey questionnaires were designed for hotel managers and guests, with 25 and 300 forms, respectively. The results indicated that hotel managers are highly willing to recycle food waste to produce bioenergy and hence play an effective role in environmental preservation. Such alternative energy sources are less expensive than conventional ones. This study revealed guests’ intentions to participate in the process of preserving the surrounding environment, as well as their preferences to stay in hotels that are practicing food waste recycling operations. Limitations can be seen in the lack of advertising for such hotels as well the high cost of staying in green and ecological hotels.

scholarly journals Proposal to Refine Solar Radiation of Typical Meteorological Year Database and Evaluation on the Influence of Air-Conditioning Load

Atmosphere ◽  
2021 ◽  
Vol 12 (4) ◽  
pp. 524
Author(s):  
Jihui Yuan ◽  
Kazuo Emura ◽  
Craig Farnham
Keyword(s):  
Solar Radiation ◽  
Air Conditioning ◽  
Energy Savings ◽  
Energy Resource ◽  
Global Solar Radiation ◽  
Resource Assessment ◽  
Weather Data ◽  
Diffuse Solar Radiation ◽  
Chinese Standard ◽  
The Impact

The Typical meteorological year (TMY) database is often used to calculate air-conditioning loads, and it directly affects the building energy savings design. Among four kinds of TMY databases in China—including Chinese Typical Year Weather (CTYW), International Weather for Energy Calculations (IWEC), Solar Wind Energy Resource Assessment (SWERA) and Chinese Standard Weather Data (CSWD)—only CSWD is measures solar radiation, and it is most used in China. However, the solar radiation of CSWD is a measured daily value, and its hourly value is separated by models. It is found that the cloud ratio (diffuse solar radiation divided by global solar radiation) of CSWD is not realistic in months of May, June and July while compared to the other sets of TMY databases. In order to obtain a more accurate cloud ratio of CSWD for air-conditioning load calculation, this study aims to propose a method of refining the cloud ratio of CSWD in Shanghai, China, using observed solar radiation and the Perez model which is a separation model of high accuracy. In addition, the impact of cloud ratio on air-conditioning load has also been discussed in this paper. It is shown that the cloud ratio can yield a significant impact on the air conditioning load.

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