scholarly journals High-Efficiency Removal of Cr(VI) from Wastewater by Mg-Loaded Biochars: Adsorption Process and Removal Mechanism

Materials ◽  
2020 ◽  
Vol 13 (4) ◽  
pp. 947
Author(s):  
Anyu Li ◽  
Hua Deng ◽  
Yanhong Jiang ◽  
Chenghui Ye
Keyword(s):  
Hexavalent Chromium ◽  
Adsorption Mechanism ◽  
High Efficiency ◽  
Adsorption Process ◽  
Raw Materials ◽  
Mechanism Analysis ◽  
Adsorption Effect ◽  
Magnetic Biochar ◽  
Before And After ◽  
Kinetics Of

Biochars were produced with magnesium chloride as an additive for the sorption of hexavalent chromium dissolved in water using five types of straw (from taro, corn, cassava, Chinese fir, and banana) and one type of shell (Camellia oleifera) as the raw materials. The removal of hexavalent chromium by the six biochars mainly occurred within 60 min and then gradually stabilized. The kinetics of the adsorption process were second order, the Langmuir model was followed, and the adsorption of Cr(VI) by the six biochars was characterized by Langmuir monolayer chemisorption on a heterogeneous surface. Banana straw biochar (BSB) had the best performance, which perhaps benefitted from its special structure and best adsorption effect on Cr(VI), and the theoretical adsorption capacity was calculated as 125.00 mg/g. For the mechanism analysis, Mg-loaded biochars were characterized before and after adsorption by Fourier transform infrared spectroscopy (FTIR), X-ray diffractometry (XRD), and scanning electron microscopy/energy dispersive spectroscopy (SEM-EDS). The adsorption mechanism differed from the adsorption process of conventional magnetic biochar, and biochar interactions with Cr(VI) were controlled mainly by electrostatic attraction, complexation, and functional group bonding. In summary, the six Mg-loaded biochars exhibit great potential advantages in removing Cr(VI) from wastewater and have promising potential for practical use, especially BSB, which shows super-high adsorption performance.

scholarly journals Synthesis of hydrated ferric oxide on cation exchange resin for phosphate and hardness removal in water

2022 ◽  
Vol 964 (1) ◽  
pp. 012032
Author(s):  
Le Ba Tran ◽  
Trung Thanh Nguyen ◽  
Tri Thich Le ◽  
Quynh Anh Nguyen Thi ◽  
Phuoc Toan Phan ◽  
...  
Keyword(s):  
Cation Exchange ◽  
Adsorption Process ◽  
Exchange Resin ◽  
Cation Exchange Resin ◽  
Phosphate Adsorption ◽  
Solution Ph ◽  
Adsorption Effect ◽  
Factors Affecting ◽  
Adsorption Condition ◽  
Before And After

Abstract In this study, a potential adsorbent was synthesized from iron salt and cation exchange resin (FeOOH@CR) and applied for phosphate adsorption in batch experiments. The characteristics of FeOOH@CR materials before and after phosphate adsorption were determined by FTIR, XRD, and SEM. The factors affecting the adsorption process such as reaction time, solution pH, material dosage, concentration, temperature, and competing ions were tested. Kinetic, thermodynamic and isothermal models of the adsorption process were applied to study the nature of the adsorption process. The properties of phosphate adsorption, effect of competitive ions and material reusability were also examined. Results showed that the adsorption time reached equilibrium after 48 h and the suitable adsorption condition was found at solution pH of 6.5, material dosage of 5 g/L. In addition, the durability of the material after 5 times of regeneration was investigated with the remained adsorption ability of about 55% as compared to the original one.

scholarly journals Highly effective removal of antibiotics from aqueous solution by magnetic ZnFe2O4/activated carbon composite

2020 ◽  
Vol 82 (5) ◽  
pp. 877-886
Author(s):  
Yun-Xia Li ◽  
Lei Wang ◽  
Fang-Fang Chai ◽  
Hong-Fei Jing ◽  
Zhu-Qing Gao ◽  
...  
Keyword(s):  
Activated Carbon ◽  
Adsorption Mechanism ◽  
Adsorption Process ◽  
Carbon Composite ◽  
Liquid System ◽  
Mechanism Analysis ◽  
Solution Ph ◽  
Adsorption Capacities ◽  
Effective Removal ◽  
Solid Liquid

Abstract Water pollution from antibiotics has attracted a lot of attention for its serious threat to human health. In this study, a magnetic adsorbent (zinc ferrite/activated carbon (ZnFe2O4/AC) was synthesized via microwave method to effectively remove gemifioxacin mesylate (GEM) and moxifloxacin hydrochloride (MOX). Based on the porosity of AC and the magnetism of ZnFe2O4, the resulting ZnFe2O4/AC has high adsorption capacities and can be easily separated from the solid–liquid system via a magnetic field. The largest adsorption capacities for GEM and MOX can reach up to 433.4 mg g−1 and 388.8 mg g−1, respectively, higher than those of reported adsorbents such as MIL-101 and MOF-808. Fastest adsorptions of GEM and MOX were found at 5 min, and solution pH and coexisting salts do not have a significant influence on the adsorption process. The adsorption mechanism analysis indicates that electrostatic interaction and H-bond interaction contribute to the effective adsorption.

scholarly journals Study on the adsorption of heavy metals by biochar modified with different modifiers under room temperature

2021 ◽  
Vol 293 ◽  
pp. 03014
Author(s):  
Jiajia Ding ◽  
Yu Tian ◽  
Tao Lu ◽  
Jiang Kang
Keyword(s):  
Heavy Metal ◽  
Metal Ions ◽  
Heavy Metal Ions ◽  
Room Temperature ◽  
Adsorption Mechanism ◽  
Physical Adsorption ◽  
Complexation Reaction ◽  
Waste Biomass ◽  
Adsorption Effect ◽  
Before And After

In order to obtain an environment-friendly biochar adsorption material with excellent adsorption performance, the biochar made from corn straw was modified with FeCl3, Na2S and KMnO4 as modifiers, and the adsorption effect of biochar on several heavy metal ions in water before and after modification was studied. The properties of biochar before and after modification were characterized by SEM, XRD, FTIR and BET, and the adsorption mechanism was discussed. The results showed that the three modified reagents could effectively improve the adsorption capacity of biochar for three heavy metal ions in water, and the adsorption effect was still good at room temperature. The adsorption difference is related to the specific surface area, pore structure, aromatic structure and SiO2 content of biochar. The adsorption mechanism mainly includes the complexation reaction between physical adsorption and surface functional groups. This study is beneficial to promote the resource utilization of agricultural and forestry waste biomass, and provides a certain reference basis for related research.

scholarly journals Removal of aqueous Cr(VI) by magnetic biochar derived from bagasse

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Meina Liang ◽  
Yanmei Ding ◽  
Qing Zhang ◽  
Dunqiu Wang ◽  
Huanhuan Li ◽  
...  
Keyword(s):  
Adsorption Process ◽  
Amorphous Structure ◽  
Batch Adsorption ◽  
High Adsorption ◽  
Magnetic Biochar ◽  
Adsorption Performance ◽  
Monolayer Adsorption ◽  
Before And After ◽  
Pseudo Second Order ◽  
Cr Concentration

AbstractWe prepared a novel adsorbent functionalized by bagasse magnetic biochar (BMBC). To study the removal behaviors and mechanisms of Cr(VI) by BMBC, batch adsorption experiments were conducted by modifying variables, such as pH, adsorption time, BMBC dosages, initial Cr concentration, co-existing ions, and ionic strength, and characterizing BMBC before and after Cr(VI) adsorption. BMBC was primarily composed of Fe2O3 and Fe3O4 on bagasse boichar with an amorphous structure. The specific surface area of BMBC was 81.94 m2 g−1, and the pHpzc of BMBC was 6.2. The fabricated BMBC showed high adsorption performance of Cr(VI) in aqueous solution. The maximum Cr(VI) adsorption capacity of BMBC was 29.08 mg g−1 at 25 ºC, which was much higher than that of conventional biochar sorbents. The adsorption process followed pseudo-second-order kinetics and could be explained by the involvement of the Langmuir isotherm in monolayer adsorption. The crystalline structure of Fe3O4 in the BMBC changed slightly during the adsorption process; Fe3O4 improved the adsorption of Cr(VI) on BMB. The desorption capacity of Cr(VI) was 8.21 mg g−1 when 0.2 mol L−1 NaOH was used as the desorption solution. After being reused three times, the removal efficiency is still as high as 80.36%.

EFFICIENCY OF NEW HEMOSORBENT IN ACUTE AMITRIPTYLINE AND CYCLODOL POISONING

2020 ◽  
pp. 14-18
Author(s):  
A. M. Fomin
Keyword(s):  
Clinical Effect ◽  
High Efficiency ◽  
Initial Level ◽  
Synthetic Polymer ◽  
Complex Treatment ◽  
Direct Hemoperfusion ◽  
Selective Sorption ◽  
Positive Clinical Effect ◽  
Before And After

A complex treatment of a patient with acute amitriptyline and cyclodol poisoning using enterosorption, intestinal lavage and hemosorption on a new column with a synthetic sorbent is presented. A two-layer synthetic polymer column developed for the selective sorption of cytokines by direct hemoperfusion was used for hemosorption. Quantitative determinations of amitriptyline and cyclodol levels before and after the column, as well as before and after hemosorption have showed high efficiency of the sorbent to remove the toxicant from the blood. The use of 6-hour hemosorption allowed to reduce the level of amitriptyline from the initial level by more than 4 times and the level of cyclodol - by more than 3 times to therapeutic levels and to obtain a pronounced positive clinical effect in the complex treatment of a patient with severe poisoning.

Sorption of Bisphenol A in Aqueous Solutions on Irradiated and as-Grown Multiwalled Carbon Nanotubes

2018 ◽  
Vol 69 (5) ◽  
pp. 1233-1239
Author(s):  
Raluca Madalina Senin ◽  
Ion Ion ◽  
Ovidiu Oprea ◽  
Rusandica Stoica ◽  
Rodica Ganea ◽  
...  
Keyword(s):  
Carbon Nanotubes ◽  
Bisphenol A ◽  
Aqueous Solutions ◽  
Adsorption Capacity ◽  
Multiwalled Carbon Nanotubes ◽  
Adsorption Process ◽  
Sorption Process ◽  
Multiwalled Carbon ◽  
Before And After ◽  
Kinetic Sorption

In this study, non-irradiated and weathered multiwalled carbon nanotubes (MWCNTs) obtained through irradiation, were studied as adsorbents for BPA, both nanomaterials being characterized before and after the adsorption process. The objectives of our investigation were to compare the characteristics of non-irradiated and irradiated MWCNTs, to evaluate the adsorption capacity of BPA by pristine and irradiated MWCNTs and to determine the variation of the kinetic, sorption and thermodynamic parameters during sorption process using both sorbents.

Investigation of Adsorption Effect of Carbon Monoxide on Coniine: A DFT Study

2021 ◽  
Vol 17 ◽  
Author(s):  
Siyamak Shahab ◽  
Masoome Sheikhi ◽  
Mehrnoosh Khaleghian ◽  
Marina Murashko ◽  
Mahin Ahmadianarog ◽  
...  
Keyword(s):  
Carbon Monoxide ◽  
Gas Phase ◽  
Density Functional ◽  
Energy Gap ◽  
Adsorption Effect ◽  
Chemical Shift Tensors ◽  
Solvent Water ◽  
Donor And Acceptor ◽  
Before And After ◽  
Electron Donor And Acceptor

: For the first time in the present study, the non-bonded interaction of the Coniine (C8H17N) with carbon monoxide (CO) was investigated by density functional theory (DFT/M062X/6-311+G*) in the gas phase and solvent water. The adsorption of the CO over C8H17N was affected on the electronic properties such as EHOMO, ELUMO, the energy gap between LUMO and HOMO, global hardness. Furthermore, chemical shift tensors and natural charge of the C8H17N and complex C8H17N/CO were determined and discussed. According to the natural bond orbital (NBO) results, the molecule C8H17N and CO play as both electron donor and acceptor at the complex C8H17N/CO in the gas phase and solvent water. On the other hand, the charge transfer is occurred between the bonding, antibonding or nonbonding orbitals in two molecules C8H17N and CO. We have also investigated the charge distribution for the complex C8H17N/CO by molecular electrostatic potential (MEP) calculations using the M062X/6-311+G* level of theory. The electronic spectra of the C8H17N and complex C8H17N/CO were calculated by time dependent DFT (TD-DFT) for investigation of the maximum wavelength value of the C8H17N before and after the non-bonded interaction with the CO in the gas phase and solvent water. Therefore, C8H17N can be used as strong absorbers for air purification and reduce environmental pollution.

scholarly journals A Brief Review on Solvent-Free Synthesis of Zeolites

Materials ◽  
2021 ◽  
Vol 14 (4) ◽  
pp. 788
Author(s):  
Jinlin Mei ◽  
Aijun Duan ◽  
Xilong Wang
Keyword(s):  
High Efficiency ◽  
Raw Materials ◽  
Solvent Free ◽  
High Yield ◽  
Control Synthesis ◽  
Mechanical Mixing ◽  
Synthesis Mechanism ◽  
Wastewater Pollution ◽  
Low Efficiency ◽  
Solvent Free Synthesis

The traditional hydrothermal method to prepare zeolite will inevitably use a large amount of water as a solvent, which will lead to higher autogenous pressure, low efficiency, and wastewater pollution. The solvent-free method can be used to synthesize various types of zeolites by mechanical mixing, grinding, and heating of solid raw materials, which exhibits the apparent advantages of high yield, low pollution, and high efficiency. This review mainly introduces the development process of solvent-free synthesis, preparation of hierarchical zeolite, morphology control, synthesis mechanism and applications of solvent-free methods. It can be believed that solvent-free methods will become a research focus and have enormous industrial application potential.

Study on leaching kinetics of hexavalent chromium from aged calcium-free chromium slag

2021 ◽  
pp. 1-13
Author(s):  
Quan Qi ◽  
Liang Li ◽  
Liangyu Wei ◽  
Baoming Hu ◽  
Zheng Liu ◽  
...  
Keyword(s):  
Hexavalent Chromium ◽  
Resource Utilization ◽  
Scientific Basis ◽  
Diffusion Reaction ◽  
Leaching Kinetics ◽  
Leaching Rate ◽  
Chromium Slag ◽  
Leaching Solution ◽  
Main Components ◽  
Kinetics Of

To provide a scientific basis for the resource utilization of chromium slag, this article studies the release law of hexavalent chromium in the aged calcium-free chromium slag. XRD (X-ray diffractometer) and MLA (Mineral Liberation Analyzer) were used to analyze the composition of the chromium slag; using sulfuric acid-nitric acid as the leaching solution, the release law of hexavalent chromium in chromium slag and the leaching kinetics were studied. The results show that main components of the chromium slag are magnesioferrite, chromite, hematite, hydrargillite, and spinel; chromium is mainly present in chromite and magnesioferrite; the leaching rate of hexavalent chromium increases with the increase of temperature or the decrease of pH. The analysis of leaching kinetics shows the leaching rate is controlled by the internal diffusion reaction, and the apparent activation energy is 11.93 kJ·mol–1. The chromium slag is aged in high temperature seasons, which is conducive to the precipitation of hexavalent chromium in the chromium slag, can increase the yield of chromate in the roasting kiln, and is conducive to resource utilization; chromium slag should be stored in order to prevent acid rain erosion which leads to environmental pollution risk (e.g. drinking water).

Sign in / Sign up

Export Citation Format

Share Document