1
|
Ahmad Shah SN, Zulfiqar S, Ruipérez F, Rafique M, Iqbal M, Forrester MJ, Sarwar Late MI, Cochran EW. An integrated experimental and theoretical approach to probe Cr(vi) uptake using decorated halloysite nanotubes for efficient water treatment. RSC Adv 2024; 14:2947-2960. [PMID: 38239454 PMCID: PMC10794904 DOI: 10.1039/d3ra07675j] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2023] [Accepted: 01/08/2024] [Indexed: 01/22/2024] Open
Abstract
Halloysite nanotubes (HNTs) were surface functionalized using four distinct chemical moieties (amidoxime, hydrazone, ethylenediamine (EDA), and diethylenetriamine (DETA)), producing modified HNTs (H1-H4) capable of binding with Cr(vi) ions. Advanced techniques like FTIR, XRD, SEM, and EDX provided evidence of the successful functionalization of these HNTs. Notably, the functionalization occurred on the surface of HNTs, rather than within the interlayer or lumen. These decorated HNTs were effective in capturing Cr(vi) ions at optimized sorption parameters, with adsorption rates ranging between 58-94%, as confirmed by atomic absorption spectroscopy (AAS). The mechanism of adsorption was further scrutinized through the Freundlich and Langmuir isotherms. Langmuir isotherms revealed the nearest fit to the data suggesting the monolayer adsorption of Cr(vi) ions onto the nanotubes, indicating a favorable adsorption process. It was hypothesized that Cr(vi) ions are primarily attracted to the amine groups on the modified nanotubes. Quantum chemical calculations further revealed that HNTs functionalized with hydrazone structures (H2) demonstrated a higher affinity (interaction energy -26.33 kcal mol-1) for the Cr(vi) ions. This can be explained by the formation of stronger hydrogen bonds with the NH moieties of the hydrazone moiety, than those established by the OH of oxime (H1) and longer amine chains (H3 and H4), respectively. Overall, the findings suggest that these decorated HNTs could serve as an effective and cost-efficient solution for treating water pollution.
Collapse
Affiliation(s)
- Syed Nadeem Ahmad Shah
- Department of Chemistry, School of Natural Sciences, National University of Sciences and Technology H-12 Islamabad 44000 Pakistan
| | - Sonia Zulfiqar
- Department of Chemistry, Faculty of Science, University of Ostrava 30. Dubna 22 Ostrava 701 03 Czech Republic
- Department of Chemical and Biological Engineering, Iowa State University Sweeney Hall, 618 Bissell Road, Ames Iowa 50011 USA
| | - Fernando Ruipérez
- POLYMAT, Physical Chemistry Department, Faculty of Pharmacy, University of the Basque Country UPV/EHU 01006 Vitoria-Gasteiz Spain
| | - Muhammad Rafique
- Department of Chemistry, Quaid-i-Azam University Islamabad 45320 Pakistan
| | - Mudassir Iqbal
- Department of Chemistry, School of Natural Sciences, National University of Sciences and Technology H-12 Islamabad 44000 Pakistan
| | - Michael J Forrester
- Department of Chemical and Biological Engineering, Iowa State University Sweeney Hall, 618 Bissell Road, Ames Iowa 50011 USA
| | | | - Eric W Cochran
- Department of Chemical and Biological Engineering, Iowa State University Sweeney Hall, 618 Bissell Road, Ames Iowa 50011 USA
| |
Collapse
|
2
|
Effect of CeO 2-Reinforcement on Pb Absorption by Coconut Coir-Derived Magnetic Biochar. Int J Mol Sci 2023; 24:ijms24031974. [PMID: 36768305 PMCID: PMC9916585 DOI: 10.3390/ijms24031974] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/24/2022] [Revised: 01/11/2023] [Accepted: 01/17/2023] [Indexed: 01/21/2023] Open
Abstract
Magnetic separable biochar holds great promise for the treatment of Pb2+-contaminated wastewater. However, the absorption effect of unmodified magnetic biochar is poor. Considering this gap in knowledge, CeO2-doped magnetic coconut coir biochar (Ce-MCB) and magnetic coconut coir biochar (MCB) for Pb2+ absorption were prepared by the impregnation method, and the efficiency of Ce-MCB for Pb2+ absorption was evaluated in comparison with MCB. Conducting the absorption experiments, the study provided theoretical support for the exploration of the absorption mechanism. The quantitative analysis exposed that the enhanced absorption capacity of Ce-MCB was attributed to the increase in oxygen-containing functional groups and mineral precipitation. The Langmuir and Freundlich isotherm model showed that Ce-MCB is a suitable adsorbent for Pb2+. The absorption characteristics of Ce-MCB was fit well with the pseudo-second-order (PSO) and Langmuir models, which revealed that the absorption of Pb2+ in water was monolayer chemisorption with a maximum theoretical adsorption capacity of 140.83 mg·g-1. The adsorption capacity of Ce-MCB for Pb(II) was sustained above 70% after four cycles. In addition, the saturation magnetization intensity of Ce-MCB was 7.15 emu·g-1, which was sufficient to separate out from the solution. Overall, Ce-MCB has wide application prospects in terms of biomass resources recycling and environmental conservation.
Collapse
|
3
|
Roychoudhury P, Bose R, Dąbek P, Witkowski A. Photonic Nano-/Microstructured Diatom Based Biosilica in Metal Modification and Removal-A Review. MATERIALS (BASEL, SWITZERLAND) 2022; 15:ma15196597. [PMID: 36233939 PMCID: PMC9572592 DOI: 10.3390/ma15196597] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/16/2022] [Revised: 09/11/2022] [Accepted: 09/19/2022] [Indexed: 05/30/2023]
Abstract
The siliceous exoskeletal shells of diatoms, commonly known as frustules, have drawn attention because of their photoluminescence property and high volume to surface area. Photonic biosilica can also enhance the plasmonic sensitivity of nanoparticles. Because of this, researchers have studied the effectiveness of various metal particles after combining with biosilica. Additionally, naturally occurring diatom-based biosilica has excellent adsorption and absorption capabilities, which have already been exploited for wastewater treatment. Moreover, the nanoporous, ultra-hydrophilic frustules can easily accumulate more molecules on their surfaces. As a consequence, it becomes easier to conjugate noble metals with silica, making them more stable and effective. The main focus of this review is to agglomerate the utility of biocompatible diatom frustules, which is a no-cost natural resource of biosilica, in metal modification and removal.
Collapse
Affiliation(s)
- Piya Roychoudhury
- Institute of Marine and Environmental Sciences, University of Szczecin, Mickiewicza 16a, 70-383 Szczecin, Poland
| | - Rahul Bose
- Department of Botany, University of Calcutta, Ballygunge Circular Road 35, Kolkata 700019, India
| | - Przemysław Dąbek
- Institute of Marine and Environmental Sciences, University of Szczecin, Mickiewicza 16a, 70-383 Szczecin, Poland
| | - Andrzej Witkowski
- Institute of Marine and Environmental Sciences, University of Szczecin, Mickiewicza 16a, 70-383 Szczecin, Poland
| |
Collapse
|
4
|
Alacabey İ. Endosulfan Elimination Using Amine-Modified Magnetic Diatomite as an Adsorbent. Front Chem 2022; 10:907302. [PMID: 35720987 PMCID: PMC9205645 DOI: 10.3389/fchem.2022.907302] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2022] [Accepted: 04/25/2022] [Indexed: 11/26/2022] Open
Abstract
Pesticides are among the most dangerous developing toxins since they are very hazardous to the environment and threaten human health. In this study, researchers successfully manufactured surface-modified magnetic diatomite (m-DE-APTES) and used them as a sorbent to extract endosulfan from an aqueous solution. There is no other study like it in the scholarly literature, and the results are astounding. Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), energy dispersive X-ray (EDX), electron spin resonance (ESR), and surface area measurements were used to analyze magnetic diatomite particles with surface modification. According to the analysis results, magnetic diatomite has a wide surface area and a porous structure. Furthermore, m-DE-APTES has a higher endosulfan adsorption capacity (97.2 mg g−1) than raw diatomite (DE) (16.6 mg g−1). Adsorption statistics agree with Langmuir adsorption isotherm (R2 = 0.9905), and the adsorption occurred spontaneously at −2.576 kj mol−1 in terms of ΔGo. Finally, m-DE-APTES are a viable alternative adsorbent for removing pesticides from aqueous solutions.
Collapse
|
5
|
Rayaroth MP, Oh D, Lee CS, Chang YS. Simultaneous removal of heavy metals and dyes in water using a MgO-coated Fe 3O 4 nanocomposite: Role of micro-mixing effect induced by bubble generation. CHEMOSPHERE 2022; 294:133788. [PMID: 35104544 DOI: 10.1016/j.chemosphere.2022.133788] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/08/2021] [Revised: 01/26/2022] [Accepted: 01/27/2022] [Indexed: 06/14/2023]
Abstract
This study focused on the development of a nano-adsorbent for contaminant removal without the use of any external energy. An eco-friendly Fe3O4@MgO core-shell nanocomposite was synthesized and tested for the removal of a heavy metal, lead (Pb2+) and a dye, rhodamine B (RhB). The addition of H2O2 into the system enabled the self-mixing of the aqueous solution containing Fe3O4@MgO through the generation of bubbles. This system showed an excellent removal efficiency of 99% in just 15 min for Pb2+ and 120 min for RhB, which is far better than the control experiment (without H2O2). The cation exchange mechanism dominated in the removal of heavy metals, while the adsorptive removal of dye proceeded through the H-bonding between Mg(OH)2 and dye molecules. The removal efficiency increased exponentially with the increase of H2O2 at the optimal concentration of 5% and it was effective over a wide pH range. Moreover, the performance of the Fe3O4@MgO-H2O2 system was verified for other heavy metals such as Cd, Ni, Zn, Co, and Cu, demonstrating that the Fe3O4@MgO-H2O2 system can be widely implemented in the treatment of real water matrices contaminated with heavy metals and organic dyes.
Collapse
Affiliation(s)
- Manoj P Rayaroth
- Division of Environmental Science and Engineering, Pohang University of Science and Technology (POSTECH), Nam-gu, Pohang, 37673, Republic of Korea; Department of Process Engineering and Chemical Technology, Faculty of Chemistry, Gdansk University of Technology, 80-233, Gdańsk, 11/12 Narutowicza Str, Poland
| | - Dasom Oh
- Division of Environmental Science and Engineering, Pohang University of Science and Technology (POSTECH), Nam-gu, Pohang, 37673, Republic of Korea
| | - Chung-Seop Lee
- Division of Environmental Science and Engineering, Pohang University of Science and Technology (POSTECH), Nam-gu, Pohang, 37673, Republic of Korea
| | - Yoon-Seok Chang
- Division of Environmental Science and Engineering, Pohang University of Science and Technology (POSTECH), Nam-gu, Pohang, 37673, Republic of Korea.
| |
Collapse
|
6
|
Feng Z, Chen N, Liu T, Feng C. KHCO 3 activated biochar supporting MgO for Pb(II) and Cd(II) adsorption from water: Experimental study and DFT calculation analysis. JOURNAL OF HAZARDOUS MATERIALS 2022; 426:128059. [PMID: 34920220 DOI: 10.1016/j.jhazmat.2021.128059] [Citation(s) in RCA: 25] [Impact Index Per Article: 12.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/11/2021] [Revised: 12/06/2021] [Accepted: 12/07/2021] [Indexed: 06/14/2023]
Abstract
A new strategy that simultaneous use of KHCO3 activated biochar and nano-MgO incorporation for Pb2+ and Cd2+ removal from water was raised. After activating by KHCO3, the BC showed a higher surface area and could carry more MgO nanoparticles the BC owned. The synthesized MgO-K-BC had a large adsorption capacity for Pb2+ (1625.5 mg/g) and Cd2+ (480.8 mg/g). Multiple characterization and comparative test have been performed to demonstrate that ion-exchange, precipitation, and complexation are the main mechanisms for Pb2+ and Cd2+ removal by MgO-K-BC. In order to further explore the adsorption mechanism in-depth, the density functional theory (DFT) calculation combined with experimental results were performed. The O-top of MgO was the most stable adsorption site for Pb2+/Cd2+ adsorption compared with other adsorption sites (Mg-top, bridge, and hollow). In addition, the results of charge density maps and projected density of state (PDOS) showed that the overlap of electron cloud and orbits between MgO and Pb2+ were denser than Cd2+, indicating that MgO-K-BC had a stronger affinity for Pb2+ than Cd2+, so that, MgO-K-BC had a higher adsorption capacity for Pb2+ than Cd2+. This work provides a deep understand of the mechanism for heavy metals adsorption by metal oxide and a practical and theoretical guidance for adsorbent preparation with high adsorption ability for heavy metal.
Collapse
Affiliation(s)
- Zhengyuan Feng
- School of Water Resources and Environment, MOE Key Laboratory of Groundwater Circulation and Environmental Evolution, China University of Geosciences (Beijing), Beijing 100083, PR China
| | - Nan Chen
- School of Water Resources and Environment, MOE Key Laboratory of Groundwater Circulation and Environmental Evolution, China University of Geosciences (Beijing), Beijing 100083, PR China
| | - Tong Liu
- School of Water Resources and Environment, MOE Key Laboratory of Groundwater Circulation and Environmental Evolution, China University of Geosciences (Beijing), Beijing 100083, PR China
| | - Chuanping Feng
- School of Water Resources and Environment, MOE Key Laboratory of Groundwater Circulation and Environmental Evolution, China University of Geosciences (Beijing), Beijing 100083, PR China.
| |
Collapse
|
7
|
The preparation and characterization of calcined diatomite with high adsorption properties by CaO hydrothermal activation. Colloids Surf A Physicochem Eng Asp 2022. [DOI: 10.1016/j.colsurfa.2021.128134] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
|
8
|
Zhou W, Wu P, Zhang L, Zhu D, Zhao X, Cai Y. Heavy metal ions and particulate pollutants can be effectively removed by a gravity-driven ceramic foam filter optimized by carbon nanotube implantation. JOURNAL OF HAZARDOUS MATERIALS 2022; 421:126721. [PMID: 34358976 DOI: 10.1016/j.jhazmat.2021.126721] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/07/2021] [Revised: 07/14/2021] [Accepted: 07/20/2021] [Indexed: 06/13/2023]
Abstract
It is of great significance to develop a new gravity-driven filter to remove water pollutants, but it is still challenging. Here, a novel and simple strategy is demonstrated to manufacture fly ash (FA) ceramic foams showing a three-dimensional interconnected porous structure, with multiwalled carbon nanotubes (MWCNTs) implanted by combining carbamate grafting and polydimethylsiloxane coating. The polydimethylsiloxane formed a physical coating on the carbamate group, generating an effective thermal insulating layer on the outer side of the entire MWCNT. The FA foam, which shows a sufficient adsorption capacity for Pb(II) (51.67 ± 1.17 mg g-1) and Cd(II) (30.12 ± 0.37 mg g-1) at pH = 5, T = 25 °C, has a 96.33%, 95.12%, 89.50% removal efficiency for Cd(II), Pb(II), and particulate pollutants, and exhibits excellent recycling performance. This paper provides new opportunities to fabricate gravity-driven filters with low energy consumption for wastewater treatment.
Collapse
Affiliation(s)
- Wei Zhou
- College of Water Resources and Architectural Engineering, Northwest A&F University, Yangling, Shaanxi 712100, PR China
| | - Pute Wu
- Institute of Soil and Water Conservation, Northwest A&F University, Yangling, Shaanxi 712100, PR China.
| | - Lin Zhang
- Institute of Soil and Water Conservation, Northwest A&F University, Yangling, Shaanxi 712100, PR China
| | - Delan Zhu
- College of Water Resources and Architectural Engineering, Northwest A&F University, Yangling, Shaanxi 712100, PR China
| | - Xining Zhao
- Institute of Soil and Water Conservation, Northwest A&F University, Yangling, Shaanxi 712100, PR China
| | - Yaohui Cai
- Institute of Soil and Water Conservation, Northwest A&F University, Yangling, Shaanxi 712100, PR China
| |
Collapse
|
9
|
Khan S, Idrees M, Bilal M. Revealing and elucidating chemical speciation mechanisms for lead and nickel adsorption on zeolite in aqueous solutions. Colloids Surf A Physicochem Eng Asp 2021. [DOI: 10.1016/j.colsurfa.2021.126711] [Citation(s) in RCA: 19] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
|
10
|
Ahmed W, Mehmood S, Núñez-Delgado A, Qaswar M, Ali S, Ying H, Liu Z, Mahmood M, Chen DY. Fabrication, characterization and U(VI) sorption properties of a novel biochar derived from Tribulus terrestris via two different approaches. THE SCIENCE OF THE TOTAL ENVIRONMENT 2021; 780:146617. [PMID: 34030312 DOI: 10.1016/j.scitotenv.2021.146617] [Citation(s) in RCA: 22] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/06/2021] [Revised: 03/15/2021] [Accepted: 03/16/2021] [Indexed: 06/12/2023]
Abstract
Water contamination due to radionuclides is considered a crucial environmental issue. In this study, Tribulus terrestris plant biomass was used as a precursor for obtaining biochar (BC), that was further modified by two different methods using FeCl3 to obtain two different magnetic biochars. Both (one-step biochar, called 1S-BC, and two-steps biochar, called 2S-BC) were studied to investigate their capability for adsorbing/removing uranium (VI) from aqueous solutions. The U(VI) removal efficacy of both biochars was tested for different values of pH, ionic strength, initial concentration of U(VI) and temperature. Experimental adsorption data fitted well to the Freundlich model (achieving as highest value for adsorption capacity KF = 49.56 mg g-1 (mg L-1)-1/n, R2 = 0.99). Thermodynamic studies revealed that adsorption was endothermic, characterized by inner-sphere complexation, and entropy-driven with a relatively increased randomness in the solid-solution interface. X-ray photoelectron spectroscopy (XPS) revealed that U(VI) sorption took place by surface complexation between U(VI) and oxygen containing functional groups on both biochars. Five consecutive regeneration cycles verified an excellent reusability for 1S-BC. The overall results allow to conclude that the FeCl3 modification of the biochar obtained from Tribulus terrestris plant biomass could give an efficient alternative adsorbent for U(VI) removal in a variety of environmental conditions, promoting protection of the environment and human health, as well as facilitating resource utilization and sustainable management of the materials studied.
Collapse
Affiliation(s)
- Waqas Ahmed
- Guangdong Provincial Key Laboratory for Radionuclides Pollution Control and Resources, School of Environmental Science and Engineering, Guangzhou University, Guangzhou 510006, China; School of Civil Engineering, Guangzhou University, Guangzhou 510006, PR China
| | - Sajid Mehmood
- Guangdong Provincial Key Laboratory for Radionuclides Pollution Control and Resources, School of Environmental Science and Engineering, Guangzhou University, Guangzhou 510006, China; School of Civil Engineering, Guangzhou University, Guangzhou 510006, PR China
| | - Avelino Núñez-Delgado
- Department of Soil Science and Agricultural Chemistry, Engineering Polytechnic School, Universidade de Santiago de Compostela, 27002 Lugo, Spain
| | - Muhammad Qaswar
- Key Laboratory of Industrial Ecology and Environmental Engineering, School of Environmental Science and Technology, Dalian University of Technology, Dalian 116024, China
| | - Sehrish Ali
- National Engineering Laboratory for Improving Quality of Arable Land, Institute of Agricultural Resources and Regional Planning, Chinese Academy of Agricultural Sciences, Beijing 100081, China
| | - Huang Ying
- Guangdong Provincial Key Laboratory for Radionuclides Pollution Control and Resources, School of Environmental Science and Engineering, Guangzhou University, Guangzhou 510006, China; School of Civil Engineering, Guangzhou University, Guangzhou 510006, PR China
| | - Zequan Liu
- Guangdong Provincial Key Laboratory for Radionuclides Pollution Control and Resources, School of Environmental Science and Engineering, Guangzhou University, Guangzhou 510006, China; School of Civil Engineering, Guangzhou University, Guangzhou 510006, PR China
| | - Mohsin Mahmood
- Key Laboratory of Plant Nutrition and the Agri-environment in Northwest China, Ministry of Agriculture, College of Natural Resources and Environment, Northwest Agriculture and Forestry (A & F) University, Yangling 712100, China
| | - Di-Yun Chen
- Guangdong Provincial Key Laboratory for Radionuclides Pollution Control and Resources, School of Environmental Science and Engineering, Guangzhou University, Guangzhou 510006, China; School of Civil Engineering, Guangzhou University, Guangzhou 510006, PR China.
| |
Collapse
|
11
|
Chen L, Li Z, Li W, Chen Z, Chen G, Yang W, Zhang X, Liu X. Investigation of Adsorption Kinetics and the Isotherm Mechanism of Manganese by Modified Diatomite. ACS OMEGA 2021; 6:16402-16409. [PMID: 34235311 PMCID: PMC8246448 DOI: 10.1021/acsomega.1c01204] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/05/2021] [Accepted: 06/03/2021] [Indexed: 05/27/2023]
Abstract
Natural diatomite modified by acetic acid (C-D) and sodium hydroxide (Na-D) for adsorbing manganese (Mn) was studied. The construction and morphology of the modified diatomite were then characterized by different efficient and accurate detection methods (Fourier transform infrared, scanning electron microscopy, and Brunauer-Emmett-Teller), and it was proved that C-D and Na-D increased the surface area and void volume compared to natural diatomite, and the modification of diatomite with acetic acid and alkali also significantly changed the structure of the functional groups of diatomite, especially in Na-D. Therefore, the adsorption rate of Mn by C-D and Na-D was higher than that of natural diatomite. The optimum conditions of Mn adsorption for C-D and Na-D were pH 5.0, 40 °C, 30 min and pH 5.0, 40 °C, 120 min, respectively, and this was best illustrated by pseudo-second-order kinetics. The Mn adsorption isotherm models showed that Mn adsorption on C-D and Na-D was stable, and the Langmuir adsorption isotherm model fitted adsorption processes of natural diatomite, C-D, and Na-D well as their correlation coefficients were 0.931, 0.940, and 0.991, respectively. These results suggested that modified diatomite with acetic acid and sodium hydroxide significantly increased the adsorption rate of Mn, which had an important application prospect for the remediation of Mn pollution in soil and water.
Collapse
Affiliation(s)
- Limei Chen
- Hunan
Province Key Laboratory of Coal Resources Clean Utilization and Mine
Environment Protection, Hunan University
of Science and Technology, Xiangtan 411201, China
| | - Zhixian Li
- Hunan
Province Key Laboratory of Coal Resources Clean Utilization and Mine
Environment Protection, Hunan University
of Science and Technology, Xiangtan 411201, China
| | - Weiya Li
- School
of Resources and Safety Engineering, Central
South University, Changsha 410083, China
| | - Zhang Chen
- Hunan
Province Key Laboratory of Coal Resources Clean Utilization and Mine
Environment Protection, Hunan University
of Science and Technology, Xiangtan 411201, China
| | - Guoliang Chen
- Hunan
Province Key Laboratory of Coal Resources Clean Utilization and Mine
Environment Protection, Hunan University
of Science and Technology, Xiangtan 411201, China
| | - Wenting Yang
- Key
Laboratory of Crop Physiology Ecology and Genetic Breeding Ministry
of Education, Jiangxi Agricultural University, Nanchang 330045, China
| | - Xinhui Zhang
- College
of Pharmacology, Ningxia Medical University, Yinchuan 750004, China
| | - Xiling Liu
- School
of Resources and Safety Engineering, Central
South University, Changsha 410083, China
| |
Collapse
|
12
|
Piri M, Sepehr E, Samadi A, Farhadi K, Alizadeh M. Application of diatomite for sorption of Pb, Cu, Cd and Zn from aqueous solutions: kinetic, thermodynamic studies and application of response surface methodology (RSM). WATER ENVIRONMENT RESEARCH : A RESEARCH PUBLICATION OF THE WATER ENVIRONMENT FEDERATION 2021; 93:714-726. [PMID: 32562331 DOI: 10.1002/wer.1377] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/21/2020] [Revised: 05/06/2020] [Accepted: 06/09/2020] [Indexed: 06/11/2023]
Abstract
Contamination of water and soil with toxic metals is a serious environmental issue. To study the Pb, Cu, Cd, and Zn sorption behavior by diatomite, batch experiments were carried out with increasing levels of initial concentration (0-200 mg/L) under different contact times (0-360 min) and temperatures (283, 293, 303, and 313 K). The effects of concentration (0-200 mg/L), pH (3-6), and ionic strength (0.01-0.06 mol/L) on the sorption were modeled using response surface methodology (RSM). Results showed that adsorption data were well-fitted by the Langmuir equation. The sorption of metals intensified by increasing initial concentration and pH but ionic strength had inverse effect. High value for R2 (0.99) and adjusted R2 (0.99) showed that the removal of ions can be described by response surface method. One-way ANOVA showed (p-value < 0.0001) that quadratic model is the best model for determining the interaction of variables. The values of the sorption energy parameter from Dubinin-Radushkevich model (E < 8 kJ K-1 mol-1 ) and negative values of ∆G showed that the sorption of the metals was physical and spontaneous. The positive values of enthalpy (ΔH) indicated that the sorption reaction of metals was endothermic at 283-313 K. PRACTITIONER POINTS: Applications of diatomite increased the sorption of Pb, Cd, Zn, and Cu from aqueous solutions. Diatomite, as low-cost adsorbent, had significant potential to sorption of ions. The sorption of heavy metals by adsorbent intensified by increasing initial concentration and pH but ionic strength had inverse effect. High value for R2 (0.99) and adj-R2 (0.99) showed that removal of metals can be described by response surface method (RSM) and the initial concentration of metal was the most significant factor.
Collapse
Affiliation(s)
- Marziyeh Piri
- Department of Soil Science, Faculty of Agriculture, Urmia University, Urmia, Iran
| | - Ebrahim Sepehr
- Department of Soil Science, Faculty of Agriculture, Urmia University, Urmia, Iran
| | - Abbas Samadi
- Department of Soil Science, Faculty of Agriculture, Urmia University, Urmia, Iran
| | - Khalil Farhadi
- Department of Chemistry, Faculty of Science, Urmia University, Urmia, Iran
| | - Mohammad Alizadeh
- Department of Food Science and Technology, Faculty of Agriculture, Urmia University, Urmia, Iran
| |
Collapse
|
13
|
Surface-functionalized pomelo peel-derived biochar with mercapto-1,2,4-triazloe for selective elimination of toxic Pb (II) in aqueous solutions. ADV POWDER TECHNOL 2021. [DOI: 10.1016/j.apt.2021.02.004] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023]
|
14
|
Ma T, Wu Y, Liu N, Yan C. Adsorption behavior of Cr(VI) and As(III) on multiwall carbon nanotubes modified by iron–manganese binary oxide (FeMnOx/MWCNTs) from aqueous solution. SEP SCI TECHNOL 2021. [DOI: 10.1080/01496395.2021.1897626] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
Affiliation(s)
- Tian Ma
- Department of Environment, Key Laboratory of Integrated Regulation and Resources Development of Shallow Lakes, Ministry of Education, Hohai University, Nanjing, China
| | - Yunhai Wu
- Department of Environment, Key Laboratory of Integrated Regulation and Resources Development of Shallow Lakes, Ministry of Education, Hohai University, Nanjing, China
| | - Ningning Liu
- Department of Environment, Key Laboratory of Integrated Regulation and Resources Development of Shallow Lakes, Ministry of Education, Hohai University, Nanjing, China
| | - Congcong Yan
- Department of Environment, Key Laboratory of Integrated Regulation and Resources Development of Shallow Lakes, Ministry of Education, Hohai University, Nanjing, China
| |
Collapse
|
15
|
Yao L, Jincheng W, Chenyang Z. Preparation of a novel flame retardant based on diatomite/polyethyleneimine modified MWCNT for applications in silicone rubber composites. J RUBBER RES 2021. [DOI: 10.1007/s42464-020-00079-z] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
|
16
|
Thomas M, Kozik V, Bąk A, Barbusiński K, Jazowiecka-Rakus J, Jampilek J. Removal of Heavy Metal Ions from Wastewaters: An Application of Sodium Trithiocarbonate and Wastewater Toxicity Assessment. MATERIALS (BASEL, SWITZERLAND) 2021; 14:655. [PMID: 33572588 PMCID: PMC7866974 DOI: 10.3390/ma14030655] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/31/2020] [Revised: 01/21/2021] [Accepted: 01/22/2021] [Indexed: 11/16/2022]
Abstract
The synthesis and application of sodium trithiocarbonate (Na2CS3) for the treatment of real galvanic wastewater in order to remove heavy metals (Cu, Cd and Zn) was investigated. A Central Composite Design/Response Surface Methodology (CCD/RSM) was employed to optimize the removal of heavy metals from industrial wastewater. Adequacy of approximated data was verified using Analysis of Variance (ANOVA). The calculated coefficients of determination (R2 and R2adj) were 0.9119 and 0.8532, respectively. Application of Na2CS3 conjugated with CCD/RSM allowed Cu, Cd and Zn levels to be decreased and, as a consequence, ∑Cu,Cd,Zn decreased by 99.80%, 97.78%, 99.78%, and 99.69%, respectively, by using Na2CS3 at 533 mg/L and pH 9.7, within 23 min. Implementation of conventional metal precipitation reagents (NaOH, Ca(OH)2 and CaO) at pH 11 within 23 min only decreased ∑Cu,Cd,Zn by 90.84%, 93.97% and 93.71%, respectively. Rotifer Brachionus plicatilis was used to conduct the assessment of wastewater toxicity. Following the application of Na2CS3, after 60 min the mortality of B. plicatilis was reduced from 90% to 25%. Engagement of Na2CS3 under optimal conditions caused the precipitation of heavy metals from the polluted wastewater and significantly decreased wastewater toxicity. In summary, Na2CS3 can be used as an effective heavy metal precipitating agent, especially for Cu, Cd and Zn.
Collapse
Affiliation(s)
- Maciej Thomas
- Chemiqua Water & Wastewater Company, Skawińska 25/1, 31-066 Kraków, Poland
| | - Violetta Kozik
- Institute of Chemistry, University of Silesia, Szkolna 9, 40-007 Katowice, Poland;
| | - Andrzej Bąk
- Institute of Chemistry, University of Silesia, Szkolna 9, 40-007 Katowice, Poland;
| | - Krzysztof Barbusiński
- Department of Water and Wastewater Engineering, Silesian University of Technology, Konarskiego 18, 44-100 Gliwice, Poland;
| | - Joanna Jazowiecka-Rakus
- Center for Translational Research and Molecular Biology of Cancer, Maria Skłodowska–Curie National Institute of Oncology–State Research Institute, Wybrzeże AK 15, 44-101 Gliwice, Poland;
| | - Josef Jampilek
- Department of Analytical Chemistry, Faculty of Natural Sciences, Comenius University, Ilkovicova 6, 84215 Bratislava, Slovakia;
| |
Collapse
|
17
|
Ma S, Poon S, Mulchandani A, Jassby D. The evolution of metal size and partitioning throughout the wastewater treatment train. JOURNAL OF HAZARDOUS MATERIALS 2021; 402:123761. [PMID: 33254774 DOI: 10.1016/j.jhazmat.2020.123761] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/15/2020] [Revised: 07/20/2020] [Accepted: 08/18/2020] [Indexed: 06/12/2023]
Abstract
Understanding the behavior of heavy metals in wastewater is critical for the development of metal removal and detection techniques. In this study, we characterize the dynamic and evolving size and partitioning behavior of lead (Pb), cadmium (Cd), and arsenite (As(III)) throughout the wastewater treatment train (WWTT). Metal concentrations were determined in three size fractions (>0.45 μm, 0.45 μm - 5 kDa, and <5 kDa), and the partitioning/complexation of the metals was quantified for the <0.45 μm fraction. Cd was found to be highly mobile, with the fraction of dissolved Cd gradually increasing throughout the WWTT. As(III) was also highly mobile, with its size distribution and partitioning remaining largely steady, except when FeCl3 was used as a flocculation agent, which led to the formation of arsenic/iron complexes. However, Pb was found primarily in complex forms or adsorbed onto inorganic particulates. The WWTT had little impact on the size and partitioning of Pb, except that the formation of the Pb/iron complex occurred after flocculation with FeCl3. An increase of water hardness slightly increased the metals in the dissolved fraction. Overall, this study provides insight into the evolution of metals throughout the WWTT, offering guidance to users and researchers regarding their treatment and detection.
Collapse
Affiliation(s)
- Shengcun Ma
- Department of Civil and Environmental Engineering, University of California, Los Angeles, CA 90095, USA
| | - Sidney Poon
- Department of Civil and Environmental Engineering, University of California, Berkeley, CA 94720, USA
| | - Ashok Mulchandani
- Department of Chemical and Environmental Engineering, University of California, Riverside, CA 92521, USA
| | - David Jassby
- Department of Civil and Environmental Engineering, University of California, Los Angeles, CA 90095, USA.
| |
Collapse
|
18
|
Wang W. Equilibrium, kinetics and thermodynamics study on the adsorption of Cr(VI) and as(III) by diatomite-modified MnO2. J DISPER SCI TECHNOL 2020. [DOI: 10.1080/01932691.2020.1845720] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
Affiliation(s)
- Wenjing Wang
- School of Civil and Hydraulic Engineering, Hefei University of Technology, Hefei, PR China
- State Key Laboratory of Urban Water Resource and Environment, Harbin Institute of Technology, Harbin, PR China
| |
Collapse
|
19
|
Removal of strontium by high-performance adsorbents Saccharomyces cerevisiae-Fe3O4 bio-microcomposites. J Radioanal Nucl Chem 2020. [DOI: 10.1007/s10967-020-07339-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
|
20
|
Khan ZH, Gao M, Qiu W, Song Z. Properties and adsorption mechanism of magnetic biochar modified with molybdenum disulfide for cadmium in aqueous solution. CHEMOSPHERE 2020; 255:126995. [PMID: 32416394 DOI: 10.1016/j.chemosphere.2020.126995] [Citation(s) in RCA: 50] [Impact Index Per Article: 12.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/20/2020] [Revised: 05/03/2020] [Accepted: 05/04/2020] [Indexed: 06/11/2023]
Abstract
In this paper, we present the preparation of MoS2-modified magnetic biochar (MoS2@MBC) as a novel adsorbent by a simple hydrothermal method. MoS2@MBC contains abundant S-containing functional groups that facilitate efficient Cd(II) removal from aqueous systems. We employed various characterization techniques to explore the morphology, surface area, and chemical composition of MoS2@MBC; these included Brunauer-Emmett-Teller analysis scanning electron microscopy, Fourier transform infrared spectroscopy, X-ray photoelectron spectroscopy, and X-ray diffraction,. The results indicated the successful decoration of the surface of MoS2@MBC with iron and MoS2, and a higher surface area of MoS2@MBC than that of unmodified biochar. Moreover, adsorption properties including thermodynamics and kinetics were investigated along with the effects of pH, humic acid, and ionic strength on the Cd(II) adsorption onto MoS2@MBC. The O-, C-, S-, and Fe-containing functional groups on the surface of MoS2@MBC led to an electrostatic attraction of Cd(II) and strong Cd-S complexation. The Langmuir and pseudo second-order models fitted best for the batch adsorption experiments results. The adsorption capacity of MoS2@MBC (139 mg g-1 on the basis of the Langmuir model) was 7.81 times higher than that of pristine biochar. The adsorption process was found to be pH-dependent. The experimental results indicated that MoS2@MBC is an effective adsorbent for removing Cd(II) from water solutions. Further, the adsorption process involved the complexation of Cd(II) with oxygen-based functional groups, ion exchange, electrostatic attraction, Cd(II)-π interactions, metal-sulfur complexation, and inner-surface complexation. This work provides new insights into the Cd(II) ions removal from water via adsorption. It also demonstrates that MoS2@MBC is an efficient and economic adsorbent to treat Cd(II)-contaminated water.
Collapse
Affiliation(s)
- Zulqarnain Haider Khan
- Agro-Environmental Protection Institute, Ministry of Agriculture of China, Tianjin, 300191, China; Chinese Academy of Agricultural Sciences, Beijing, 100081, China
| | - Minling Gao
- Department of Civil and Environmental Engineering, Shantou University, Shantou, 515063, China
| | - Weiwen Qiu
- The New Zealand Institute for Plant and Food Research Limited, Private Bag 4704, Christchurch, 8140, New Zealand
| | - Zhengguo Song
- Department of Civil and Environmental Engineering, Shantou University, Shantou, 515063, China.
| |
Collapse
|
21
|
Naturally available diatomite and their surface modification for the removal of hazardous dye and metal ions: A review. Adv Colloid Interface Sci 2020; 282:102198. [PMID: 32579950 DOI: 10.1016/j.cis.2020.102198] [Citation(s) in RCA: 56] [Impact Index Per Article: 14.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2020] [Revised: 06/09/2020] [Accepted: 06/10/2020] [Indexed: 12/18/2022]
Abstract
The presence of toxic pollutants such as dyes and metal ions at higher concentrations in water is very harmful to the environment. Removal of these pollutants using diatomaceous earth or diatomite (DE) and surface-modified DE has been extensively explored due to their excellent physio-chemical properties and low cost. Therefore, naturally available DE being inexpensive, their surface modified adsorbents could be one of the potential candidates for the wastewater treatment in the future. In this context, the current review has been summarized for the removal of both pollutants i.e., dyes and metal ions by surface-modified DE using the facile adsorption process. In addition, this review is prominently focused on the various modification process of DE, their cost-effectiveness; the physio-chemical characteristics and their maximum adsorption capacity. Further, real-time scenarios of reported adsorbents were tabulated based on the cost of the process along with the adsorption capacity of these adsorbents.
Collapse
|
22
|
Alsar Z, Duskinova B, Insepov Z. New Sorption Properties of Diatomaceous Earth for Water Desalination and Reducing Salt Stress of Plants. EURASIAN CHEMICO-TECHNOLOGICAL JOURNAL 2020. [DOI: 10.18321/ectj955] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022] Open
Abstract
A new practical application of the unique sorption abilities of Diatomaceous Earth (DE) or diatomite, a widely accessible and promising natural mineral, has been studied. By analyzing aqueous extracts of natural diatomite, it was shown that DE probably contains various inorganic salts, which are released into the solution in the form of ions, such as Cl-, SO42-, Na+, Ca2+, Mg2+, K+ and, apparently, others. Diatomite was able to exchange these ions with the environment, exhibiting the properties of a natural ion exchanger. Studying the kinetics of ion release from diatomite showed that the ion desorption process continues for 4‒5 h until the surrounding solution is saturated with ions, after which it is dynamically balanced by the sorption process. In order to significantly reduce the ionic content of diatomite, DE samples were processed in a technologically simple and environmentally friendly way. Thus, as a result of deionization, the content of ions released from diatomite significantly decreases. Deionized diatomite was applied to study the adsorption of sodium and chloride ions from aqueous solutions. The maximum adsorption was 50.2 mg/g, and the maximum degree of extraction, corresponding to the concentration range of 5‒100 mg/l, was 53.9%. The observed effect was also applicable for increasing the resistance of plants to salt stress, improving the germination and growth of wheat samples. The developed method can be used in the manufacturing of filters for water desalination, both drinking and technological; in ecology; in agriculture to reduce salt stress of plants, as well as for the restoration of lands contaminated by salt.
Collapse
|
23
|
Wei Z, Zhang Y, Wang W, Dong S, Jiang T, Wei D. Synthesis of Cost-Effective Pomelo Peel Dimethoxydiphenylsilane-Derived Materials for Pyrene Adsorption: From Surface Properties to Adsorption Mechanisms. ACS OMEGA 2020; 5:9465-9476. [PMID: 32363299 PMCID: PMC7191855 DOI: 10.1021/acsomega.0c00689] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/15/2020] [Accepted: 04/09/2020] [Indexed: 05/14/2023]
Abstract
This study investigated the adsorption behaviors of pyrene (PYR) on a pomelo peel adsorbent (PPA), biochar (PPB), and H3PO4-modified (HPP), NaOH-activated (NPP), and dimethoxydiphenylsilane-treated (DPDMS-NPP) pomelo peel materials. SEM, FTIR, and elemental analyses of DPDMS-NPP's surface structure showed that the material was characterized by a well-developed porous structure, a large specific surface area (698.52 m2 g-1), and an abundance of phenyl functional groups. These properties enhance the PYR adsorption performance of DPDMS-NPP. Experimental results indicated that the adsorption capacity of DPDMS-NPP was significantly affected by the amount of material used and the initial concentration of PYR. Kinetic assessments suggested that PYR adsorption on PPA, NPP, and DPDMS-NPP could be accurately described by the pseudo second-order model. The adsorption process was controlled by several mechanisms, including electron donor-acceptor (EDA), electrostatic, and π-π interactions as well as film and intraparticle diffusion. The adsorption isotherm studies showed that PYR adsorption on DPDMS-NPP and PPA was well described by the Langmuir model and the maximum Langmuir adsorption capacity of DPDMS-NPP was 531.9 μg g-1. Overall, the results presented herein suggested that the use of DPDMS-NPP adsorbents constitutes an economic and environmentally friendly approach for the mitigation of PYR contamination risks.
Collapse
Affiliation(s)
- Zhengwen Wei
- Key Laboratory of Subsurface Hydrology and Ecological Effects in
Arid Region of the Ministry of Education, Chang’an University, No. 126 Yanta Road, Xi’an 710054, Shaanxi, China
- School of Water and Environment, Chang’an University, Xi’an 710054, P.R. China
| | - Yaoyao Zhang
- Key Laboratory of Subsurface Hydrology and Ecological Effects in
Arid Region of the Ministry of Education, Chang’an University, No. 126 Yanta Road, Xi’an 710054, Shaanxi, China
- School of Water and Environment, Chang’an University, Xi’an 710054, P.R. China
| | - Wei Wang
- Key Laboratory of Subsurface Hydrology and Ecological Effects in
Arid Region of the Ministry of Education, Chang’an University, No. 126 Yanta Road, Xi’an 710054, Shaanxi, China
- School of Water and Environment, Chang’an University, Xi’an 710054, P.R. China
- . Phone: +86-29-82339052. Fax: +86-29-82335485
| | - Suiming Dong
- Key Laboratory of Subsurface Hydrology and Ecological Effects in
Arid Region of the Ministry of Education, Chang’an University, No. 126 Yanta Road, Xi’an 710054, Shaanxi, China
- School of Water and Environment, Chang’an University, Xi’an 710054, P.R. China
| | - Tingbo Jiang
- Key Laboratory of Subsurface Hydrology and Ecological Effects in
Arid Region of the Ministry of Education, Chang’an University, No. 126 Yanta Road, Xi’an 710054, Shaanxi, China
- School of Water and Environment, Chang’an University, Xi’an 710054, P.R. China
| | - Donghui Wei
- Key Laboratory of Subsurface Hydrology and Ecological Effects in
Arid Region of the Ministry of Education, Chang’an University, No. 126 Yanta Road, Xi’an 710054, Shaanxi, China
- School of Water and Environment, Chang’an University, Xi’an 710054, P.R. China
| |
Collapse
|
24
|
Chang J, Zhang J, Tan B, Wang Q, Liu N, Xue Q. New insight into the removal of Cd(II) from aqueous solution by diatomite. ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH INTERNATIONAL 2020; 27:9882-9890. [PMID: 31927734 DOI: 10.1007/s11356-020-07620-y] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/27/2019] [Accepted: 01/02/2020] [Indexed: 06/10/2023]
Abstract
Diatomite is an economical and environmentally friendly adsorbent, and its use has been applied widely for the treatment of water contaminated by heavy metals. Despite this, the mechanism for the removal of the heavy metal Cd(II) remains unclear. In this work, we explored the adsorption mechanism of Cd(II) by diatomite using batch experiment, and characterized the diatomite using scanning electron microscopy, energy-dispersive spectrometry, specific surface area, and pore size distribution analysis. Our results showed that, under the experimental conditions, the kinetic adsorption approached equilibrium within 5 min, and the Sips isotherm model was most suitable for data fitting. EDS characterization of the Cd-loaded diatomite indicated that Cd(II) was adsorbed onto the diatomite. Furthermore, desorption experiments showed that Ca2+ and Mg2+ in the diatomite caused an ion exchange interaction, and this was primarily responsible for Cd(II) adsorption. Moreover, we found that its contribution to the whole adsorption reaction could reach 80%, while the remainder of Cd(II) was probably trapped in the microporous structure of the diatomite. Additionally, our data indicated that the adsorption mechanism did not change significantly after regeneration. These results have provided special insight into the deep understanding of the mechanism of Cd(II) adsorption by diatomite, and could provide theoretical support and guidance for further development and application of diatomite in the treatment of Cd(II)-contaminated water. Graphical abstract.
Collapse
Affiliation(s)
- Jingjie Chang
- Beijing Key Laboratory of Water Resources and Environmental Engineering, School of Water Resources and Environment, China University of Geosciences (Beijing), Beijing, 100083, People's Republic of China
| | - Jia Zhang
- Beijing Key Laboratory of Water Resources and Environmental Engineering, School of Water Resources and Environment, China University of Geosciences (Beijing), Beijing, 100083, People's Republic of China
| | - Biqi Tan
- Beijing Key Laboratory of Water Resources and Environmental Engineering, School of Water Resources and Environment, China University of Geosciences (Beijing), Beijing, 100083, People's Republic of China
| | - Qun Wang
- Beijing Key Laboratory of Water Resources and Environmental Engineering, School of Water Resources and Environment, China University of Geosciences (Beijing), Beijing, 100083, People's Republic of China
| | - Nannan Liu
- Beijing Key Laboratory of Water Resources and Environmental Engineering, School of Water Resources and Environment, China University of Geosciences (Beijing), Beijing, 100083, People's Republic of China
| | - Qiang Xue
- Beijing Key Laboratory of Water Resources and Environmental Engineering, School of Water Resources and Environment, China University of Geosciences (Beijing), Beijing, 100083, People's Republic of China.
- MOE Key Laboratory of Groundwater Circulation and Environmental Evolution, China University of Geosciences (Beijing), Beijing, 100083, People's Republic of China.
| |
Collapse
|
25
|
Wang H, Jiang DB, Gu J, Ouyang L, Zhang YX, Yuan S. Simultaneous Removal of Phenol and Pb2+ from the Mixed Solution by Zwitterionic Poly(sulfobetaine methacrylate)-Grafted Poly(vinylbenzyl chloride) Microspheres. Ind Eng Chem Res 2020. [DOI: 10.1021/acs.iecr.9b06171] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Affiliation(s)
- Hanzhi Wang
- Low-carbon Technology & Chemical Reaction Engineering Lab, College of Chemical Engineering, Sichuan University, Chengdu 610065, China
| | - De-Bin Jiang
- Low-carbon Technology & Chemical Reaction Engineering Lab, College of Chemical Engineering, Sichuan University, Chengdu 610065, China
- State Key Laboratory of Mechanical Transmissions, College of Materials Science and Engineering, Chongqing University, Chongqing 400044, China
| | - Juntao Gu
- Low-carbon Technology & Chemical Reaction Engineering Lab, College of Chemical Engineering, Sichuan University, Chengdu 610065, China
| | - Like Ouyang
- Low-carbon Technology & Chemical Reaction Engineering Lab, College of Chemical Engineering, Sichuan University, Chengdu 610065, China
| | - Yu-Xin Zhang
- State Key Laboratory of Mechanical Transmissions, College of Materials Science and Engineering, Chongqing University, Chongqing 400044, China
| | - Shaojun Yuan
- Low-carbon Technology & Chemical Reaction Engineering Lab, College of Chemical Engineering, Sichuan University, Chengdu 610065, China
| |
Collapse
|
26
|
Yang X, Guo N, Yu Y, Li H, Xia H, Yu H. Synthesis of magnetic graphene oxide-titanate composites for efficient removal of Pb(II) from wastewater: Performance and mechanism. JOURNAL OF ENVIRONMENTAL MANAGEMENT 2020; 256:109943. [PMID: 31989978 DOI: 10.1016/j.jenvman.2019.109943] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/10/2019] [Revised: 11/22/2019] [Accepted: 11/27/2019] [Indexed: 06/10/2023]
Abstract
Magnetic graphene oxide-titanate composites (MGO@TNs) were synthesized via growing titanate nanosheets on the graphene oxide sheets with magnetite nanoparticles anchored on. The as-prepared MGO@TNs showed a hierarchical structure and large specific surface area (193.4 m2/g), which were suitable for rapid and effective adsorption of Pb(II) from wastewater. Moreover, the loaded magnetite nanoparticles guaranteed the effective magnetic separation of MGO@TNs, avoiding secondary pollution. The adsorption mechanism were illuminated to be ion exchange and surface complexation. Batch adsorption experiments showed the maximum adsorption capacity of MGO@TNs reached 322.7 mg/g for Pb(II) removal. The removal efficiency retained 89.6% after six adsorption-desorption cycles. In addition, the efficiency reached up to 99.8% when applying MGO@TNs for removal of Pb(II) from simulated realistic battery wastewater, ensuring the safe discharge of treated water. The good adsorption performance, recyclability and easy magnetic separation ability made sure that the MGO@TNs has great potential for purification of Pb(II) contaminated wastewater.
Collapse
Affiliation(s)
- Xiutao Yang
- Northeast Institute of Geography and Agroecology, Chinese Academy of Sciences, 4888 Shengbei Rd, Changchun, 130102, China; University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Na Guo
- Northeast Institute of Geography and Agroecology, Chinese Academy of Sciences, 4888 Shengbei Rd, Changchun, 130102, China
| | - Yong Yu
- Northeast Institute of Geography and Agroecology, Chinese Academy of Sciences, 4888 Shengbei Rd, Changchun, 130102, China
| | - Haiyan Li
- School of Life Science and Technology, Changchun University of Science and Technology, Changchun, 130022, China
| | - Hui Xia
- School of Physics and Electronics, Central South University, Changsha, 410083, China
| | - Hongwen Yu
- Northeast Institute of Geography and Agroecology, Chinese Academy of Sciences, 4888 Shengbei Rd, Changchun, 130102, China.
| |
Collapse
|
27
|
Wang X, Zhou J, Zhao T, Gui K, Wang J, Thomas HR. Superior activity of iron-manganese supported on kaolin for NO abatement at low temperature. J Environ Sci (China) 2020; 88:237-247. [PMID: 31862065 DOI: 10.1016/j.jes.2019.08.017] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2019] [Revised: 08/26/2019] [Accepted: 08/29/2019] [Indexed: 06/10/2023]
Abstract
A series of Fe-Mn catalysts was prepared using different supports (kaolin, diatomite, and alumina) and used for NO abatement via low-temperature NH3-selective catalytic reduction (SCR). The results showed that 12Fe-10Mn/Kaolin (with the concentration of Fe and Mn 12 and 10wt.%, respectively) exhibited the highest activity, and more than 95.8% NO conversion could be obtained within the wide temperature range of 120-300°C. The properties of the catalysts were characterized by inductively coupled plasma-atomic emission spectrometry (ICP-AES), thermogravimetry (TG), Brunner-Emmet-Teller (BET) measurements, X-ray diffraction (XRD), H2-temperature programmed reduction (H2-TPR), NH3-temperature programmed desorption (NH3-TPD), X-ray photoelectron spectroscopy (XPS), scanning electron microprobe (SEM) and energy dispersive spectroscopy (EDS) techniques. The support effects resulted in significant differences in the components and structures of catalysts. The 12Fe-10Mn/Kaolin catalyst exhibited better dispersion of active species, optimum low-temperature reduction behavior, the largest amount of normalized Brønsted acid sites, and the highest Mn4+/Mn and Fe3+/(Fe3++Fe2+), all of which may be major reasons for its superior catalytic activity.
Collapse
Affiliation(s)
- Xiaobo Wang
- School of Environmental Science, Nanjing Xiaozhuang University, Nanjing 211171, China; Geoenvironmental Research Centre, School of Engineering, Cardiff University, Cardiff CF24 3AA, UK.
| | - Jie Zhou
- School of Environmental Science, Nanjing Xiaozhuang University, Nanjing 211171, China
| | - Tong Zhao
- School of Environmental Science, Nanjing Xiaozhuang University, Nanjing 211171, China
| | - Keting Gui
- School of Energy and Environment, Southeast University, Nanjing 210096, China
| | - Jia Wang
- College of Chemical Engineering, Nanjing Forestry University, Nanjing 210037, China.
| | - Hywel R Thomas
- Geoenvironmental Research Centre, School of Engineering, Cardiff University, Cardiff CF24 3AA, UK
| |
Collapse
|
28
|
Sasirekha R, Sheena TS, Anitha R, Santhanam P, Kulandaivel J. Characterizations and analysis of genus Amphora diatom frustules: a promising biomaterial. BIOINSPIRED BIOMIMETIC AND NANOBIOMATERIALS 2019. [DOI: 10.1680/jbibn.18.00026] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/12/2023]
Abstract
In the present study, the authors have synthesized biosilica from marine diatoms (Amphora sp.) by using an optimized procedure with a combination of acid and salt washing treatments. The purification of frustules employed a simple methodology that combines acid digestion and rinsing with hydrogen peroxide. The content of Amphora sp. biosilica has been analyzed through energy-dispersive spectroscopy. The result declares the purity of biosilica, which is highly pristine in comparison to diatomaceous earth. The structural architecture of Amphora sp. is typically amorphous in nature. Moreover, Amphora sp. biosilica has a mesopore diameter and a surface area of 4·838 nm and 332 m2/g, respectively, which are relatively higher than those from previous reports. The adsorption/desorption isotherm results suggest that the derived frustules have a highly porous architecture, which shows their great potential to be used as drug delivery carriers, biosensors, biocatalysts and adsorbents in the future.
Collapse
Affiliation(s)
- Rajendran Sasirekha
- Department of Marine Science, School of Marine Sciences, Bharathidasan University, Tiruchirapalli, India
| | - Thankaraj Salammal Sheena
- Center for Nanoscience and Nanotechnology, Department of Physics, Bharathidasan University, Tiruchirapalli, India
| | - Radhakrishnan Anitha
- Department of Botany, School of Life Sciences, Bharathidasan University, Tiruchirapalli, India
| | - Perumal Santhanam
- Department of Marine Science, School of Marine Sciences, Bharathidasan University, Tiruchirapalli, India
| | - Jeganathan Kulandaivel
- Center for Nanoscience and Nanotechnology, Department of Physics, Bharathidasan University, Tiruchirapalli, India
| |
Collapse
|
29
|
Sha'arani S, Azizan SNF, Md Akhir FN, Muhammad Yuzir MA, Othman N, Zakaria Z, Mohd Noor MJM, Hara H. Removal efficiency of Gram-positive and Gram-negative bacteria using a natural coagulant during coagulation, flocculation, and sedimentation processes. WATER SCIENCE AND TECHNOLOGY : A JOURNAL OF THE INTERNATIONAL ASSOCIATION ON WATER POLLUTION RESEARCH 2019; 80:1787-1795. [PMID: 32039910 DOI: 10.2166/wst.2019.433] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
Staphylococcus sp. as Gram-positive and Escherichia coli as Gram-negative are bacterial pathogens and can cause primary bloodstream infections and food poisoning. Coagulation, flocculation, and sedimentation processes could be a reliable treatment for bacterial removal because suspended, colloidal, and soluble particles can be removed. Chemical coagulants, such as alum, are commonly used. However, these chemical coagulants are not environmentally friendly. This present study evaluated the effectiveness of coagulation, flocculation, and sedimentation processes for removing Staphylococcus sp. and E. coli using diatomite with standard jar test equipment at different pH values. Staphylococcus sp. demonstrated 85.61% and 77.23% significant removal in diatomite and alum, respectively, at pH 5. At pH 7, the removal efficiency decreased to 79.41% and 64.13% for Staphylococcus sp. and E. coli, respectively. At pH 9, there was a decrease in Staphylococcus sp. after adding diatomite or alum compared with that of E. coli. The different removal efficiencies of the Gram-positive and Gram-negative bacteria could be owing to the membrane composition and different structures in the bacteria. This study indicates that diatomite has higher efficiency in removing bacteria at pH 5 and can be considered as a potential coagulant to replace alum for removing bacteria by the coagulation process.
Collapse
Affiliation(s)
- Shazwana Sha'arani
- Department of Environmental Engineering and Green Technology, Malaysia-Japan International Institute of Technology, Universiti Teknologi Malaysia, Jalan Sultan Yahya Petra, 54100 Kuala Lumpur, Malaysia
| | - Siti Noor Fitriah Azizan
- Department of Environmental Engineering and Green Technology, Malaysia-Japan International Institute of Technology, Universiti Teknologi Malaysia, Jalan Sultan Yahya Petra, 54100 Kuala Lumpur, Malaysia
| | - Fazrena Nadia Md Akhir
- Department of Environmental Engineering and Green Technology, Malaysia-Japan International Institute of Technology, Universiti Teknologi Malaysia, Jalan Sultan Yahya Petra, 54100 Kuala Lumpur, Malaysia
| | - Muhamad Ali Muhammad Yuzir
- Department of Environmental Engineering and Green Technology, Malaysia-Japan International Institute of Technology, Universiti Teknologi Malaysia, Jalan Sultan Yahya Petra, 54100 Kuala Lumpur, Malaysia
| | - Nor'azizi Othman
- Department of Mechanical Precision Engineering, Malaysia-Japan International Institute of Technology, Universiti Teknologi Malaysia, Jalan Sultan Yahya Petra, 54100 Kuala Lumpur, Malaysia
| | - Zuriati Zakaria
- Department of Environmental Engineering and Green Technology, Malaysia-Japan International Institute of Technology, Universiti Teknologi Malaysia, Jalan Sultan Yahya Petra, 54100 Kuala Lumpur, Malaysia
| | - Megat Johari Megat Mohd Noor
- Department of Environmental Engineering and Green Technology, Malaysia-Japan International Institute of Technology, Universiti Teknologi Malaysia, Jalan Sultan Yahya Petra, 54100 Kuala Lumpur, Malaysia
| | - Hirofumi Hara
- Department of Chemical Process Engineering, Malaysia-Japan International Institute of Technology, Universiti Teknologi Malaysia, Jalan Sultan Yahya Petra, 54100 Kuala Lumpur, Malaysia E-mail:
| |
Collapse
|
30
|
Erol K, Yıldız E, Alacabey İ, Karabörk M, Uzun L. Magnetic diatomite for pesticide removal from aqueous solution via hydrophobic interactions. ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH INTERNATIONAL 2019; 26:33631-33641. [PMID: 31587166 DOI: 10.1007/s11356-019-06423-0] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/13/2019] [Accepted: 09/03/2019] [Indexed: 06/10/2023]
Abstract
Pesticides are highly hazardous chemicals for the environment and human health and their use in agriculture is constantly increasing. Although 1,1,1-trichloro-2,2-bis(4-chlorophenyl) ethane 4,4'-DDT was banned at developed countries, it is still one of the most dangerous of chemical due to accumulation in the environment. It is known that the toxicity of DDT affects some enzyme systems biochemically. The main motivation of this study is to develop an effective adsorbate for the removal DDT, which was chosen as a model hydrophobic pesticide, out of aqueous systems. For this purpose, the bare diatomite particles were magnetically modified and a hydrophobic ligand attached to enhance its adsorptive and physio-chemical features. Under optimal conditions, a high adsorption capacity, around 120 mg/g with the hydrophobic and magnetic diatomite particles, modification of the diatomite particles reduced average pores diameter whereas surface area and total pore volume increased (around 15-folds). After five consecutive adsorption-desorption cycles, no significant decrease in adsorption capability was observed. The adsorption isotherms (Langmuir, Freundlich, and Flory-Huggins) applied to the data indicated that the adsorption process occurred via monolayer adsorption in an entropy-driven manner. The kinetic data also revealed the quick adsorption process without any diffusion limitations. Graphical Abstract.
Collapse
Affiliation(s)
- Kadir Erol
- Department of Property Protection and Security, Osmancık Ömer Derindere Vocational School, Hitit University, 19500, Osmancık, Turkey.
| | - Emrecan Yıldız
- Department of Chemistry, Faculty of Science, Hacettepe University, 06800, Ankara, Turkey
| | - İhsan Alacabey
- Vocational School of Health Services, Mardin Artuklu University, 47200, Mardin, Turkey
| | - Muharrem Karabörk
- Department of Chemistry, Faculty of Arts and Sciences, Kahramanmaraş Sütçü İmam University, 46100, Kahramanmaraş, Turkey
| | - Lokman Uzun
- Department of Chemistry, Faculty of Science, Hacettepe University, 06800, Ankara, Turkey
- Advanced Technologies Application and Research Center, Hacettepe University, 06800, Ankara, Turkey
| |
Collapse
|
31
|
Liu Y, Hu L, Yao Y, Su Z, Hu S. Construction of composite chitosan-glucose hydrogel for adsorption of Co2+ ions. Int J Biol Macromol 2019; 139:213-220. [DOI: 10.1016/j.ijbiomac.2019.07.202] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2019] [Revised: 07/26/2019] [Accepted: 07/29/2019] [Indexed: 01/27/2023]
|
32
|
Choumane R, Peulon S. Electrodeposited birnessite thin film: An efficient eco-friendly sorbent for removing heavy metals from water. Colloids Surf A Physicochem Eng Asp 2019. [DOI: 10.1016/j.colsurfa.2019.06.013] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
|
33
|
Chu Y, Zhang X, Chen W, Wu F, Wang P, Yang Y, Tao S, Wang X. Plasma assisted-synthesis of magnetic TiO 2/SiO 2/Fe 3O 4-polyacrylic acid microsphere and its application for lead removal from water. THE SCIENCE OF THE TOTAL ENVIRONMENT 2019; 681:124-132. [PMID: 31102813 DOI: 10.1016/j.scitotenv.2019.05.064] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/23/2019] [Revised: 05/05/2019] [Accepted: 05/06/2019] [Indexed: 06/09/2023]
Abstract
Hybrid microsphere of polyacrylic acid (PAA) grafted TiO2/SiO2/Fe3O4 (TSF-PAA) was synthesized via coating polyacrylic acid on the core-shell-shell TiO2/SiO2/Fe3O4 (TSF) structure with the aid of plasma technique. The synthesized microsphere was applied to remove Pb2+ from water. The state-of-the techniques including TEM, FTIP, TGA, and XPS were used to characterize the morphology and the surface functionalities of the microsphere and confirmed that PAA was successfully grafted on TSF surfaces and active functional groups were introduced. A combination of the BET, VSM, and XRD results showed that plasma treatment decreased surface area of TSF by 36%, whereas its magnetic property and crystalline structure were not significantly altered. Both the Pb2+-sorbed magnetic TSF and TSF-PAA can be separated with a magnet from the aqueous phase. The pH and dosage changes of the microspheres exerted an intense influence on their lead removal efficiency. Compared to TSF, the removal capacity of Pb2+ by TSF-PAA was considerably improved from 65% to 95%, attributable to the fact that PAA coating induced by plasma treatment additionally introduced carboxylic and hydroxyl groups to TSF. Their introduction greatly enhanced the interaction between Pb2+ and TSF-PAA relative to that with TSF, which had hydroxyl groups only as supported by XPS analysis.
Collapse
Affiliation(s)
- Yangyang Chu
- Laboratory for Earth Surface Processes, College of Urban and Environmental Sciences, Peking University, Beijing 100871, China
| | - Xinyu Zhang
- Laboratory for Earth Surface Processes, College of Urban and Environmental Sciences, Peking University, Beijing 100871, China
| | - Weixiao Chen
- Laboratory for Earth Surface Processes, College of Urban and Environmental Sciences, Peking University, Beijing 100871, China
| | - Fan Wu
- Laboratory for Earth Surface Processes, College of Urban and Environmental Sciences, Peking University, Beijing 100871, China
| | - Peng Wang
- Water Desalination and Reuse Center, King Abdullah University of Science and Technology, Thuwal 23955-6900, Saudi Arabia
| | - Yu Yang
- Department of Civil and Environmental Engineering, University of Nevada, Reno, NV 89557, USA
| | - Shu Tao
- Laboratory for Earth Surface Processes, College of Urban and Environmental Sciences, Peking University, Beijing 100871, China
| | - Xilong Wang
- Laboratory for Earth Surface Processes, College of Urban and Environmental Sciences, Peking University, Beijing 100871, China.
| |
Collapse
|
34
|
Preparation and characterization of a novel diatomite-based composite and investigation of its adsorption properties for uranyl ions. J Radioanal Nucl Chem 2019. [DOI: 10.1007/s10967-019-06662-y] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
|
35
|
Zhang Y, Tian Z, Jing Q, Chen Y, Huang X. Removal of Cr(VI) by modified diatomite supported NZVI from aqueous solution: evaluating the effects of removal factors by RSM and understanding the effects of pH. WATER SCIENCE AND TECHNOLOGY : A JOURNAL OF THE INTERNATIONAL ASSOCIATION ON WATER POLLUTION RESEARCH 2019; 80:308-316. [PMID: 31537767 DOI: 10.2166/wst.2019.275] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
In this study, a novel composite of modified diatomite supported nanoscale zero-valent iron (mD-NZVI) was synthesized and characterized. The effects of four factors (mD-NZVI dose, temperature, contact time and initial pH) on the removal of Cr(VI) by mD-NZVI were studied by experimental work and analyzed by response surface methodology (RSM). A second-order polynomial equation fitted by Box-Behnken design was used as a statistical model and proved to be precise in describing the significance of four factors. The analysis results show that the effects of four factors on the removal efficiency of Cr(VI) were significant (F value is 19.83), initial pH was found to be the key factor. In addition, the effect of initial pH was further studied and the maximum removal efficiency of 89.34% was obtained at pH of 3, the decrease in removal efficiency with the increase in pH is a synergistic effect of Cr(VI) species, surface charge of mD-NZVI and OH- amount at different pH.
Collapse
Affiliation(s)
- Yongxiang Zhang
- College of Architecture and Civil Engineering, Beijing University of Technology, Beijing 100124, China E-mail:
| | - Zhenjun Tian
- College of Architecture and Civil Engineering, Beijing University of Technology, Beijing 100124, China E-mail:
| | - Qi Jing
- College of Architecture and Civil Engineering, Beijing University of Technology, Beijing 100124, China E-mail:
| | - Yuanyuan Chen
- College of Architecture and Civil Engineering, Beijing University of Technology, Beijing 100124, China E-mail:
| | - Xuezheng Huang
- College of Architecture and Civil Engineering, Beijing University of Technology, Beijing 100124, China E-mail: ; School of Civil Engineering, Nanyang Institute of Technology, Nanyang 473004, China
| |
Collapse
|
36
|
Zhao Y, Tian G, Duan X, Liang X, Meng J, Liang J. Environmental Applications of Diatomite Minerals in Removing Heavy Metals from Water. Ind Eng Chem Res 2019. [DOI: 10.1021/acs.iecr.9b01941] [Citation(s) in RCA: 45] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Yan Zhao
- (Key Laboratory of Special Functional Materials for Ecological Environment and Information, Ministry of Education, Hebei University of Technology, Tianjin 300130, People’s Republic of China
| | - Guangyan Tian
- (Key Laboratory of Special Functional Materials for Ecological Environment and Information, Ministry of Education, Hebei University of Technology, Tianjin 300130, People’s Republic of China
- Institute of Power Source and Ecomaterials Science, Hebei University of Technology, Tianjin 300130, People’s Republic of China
| | - Xinhui Duan
- (Key Laboratory of Special Functional Materials for Ecological Environment and Information, Ministry of Education, Hebei University of Technology, Tianjin 300130, People’s Republic of China
- Institute of Power Source and Ecomaterials Science, Hebei University of Technology, Tianjin 300130, People’s Republic of China
| | - Xiuhong Liang
- (Key Laboratory of Special Functional Materials for Ecological Environment and Information, Ministry of Education, Hebei University of Technology, Tianjin 300130, People’s Republic of China
- Institute of Power Source and Ecomaterials Science, Hebei University of Technology, Tianjin 300130, People’s Republic of China
| | - Junping Meng
- (Key Laboratory of Special Functional Materials for Ecological Environment and Information, Ministry of Education, Hebei University of Technology, Tianjin 300130, People’s Republic of China
- Institute of Power Source and Ecomaterials Science, Hebei University of Technology, Tianjin 300130, People’s Republic of China
| | - Jinsheng Liang
- (Key Laboratory of Special Functional Materials for Ecological Environment and Information, Ministry of Education, Hebei University of Technology, Tianjin 300130, People’s Republic of China
- Institute of Power Source and Ecomaterials Science, Hebei University of Technology, Tianjin 300130, People’s Republic of China
| |
Collapse
|
37
|
Uogintė I, Lujanienė G, Mažeika K. Study of Cu (II), Co (II), Ni (II) and Pb (II) removal from aqueous solutions using magnetic Prussian blue nano-sorbent. JOURNAL OF HAZARDOUS MATERIALS 2019; 369:226-235. [PMID: 30776605 DOI: 10.1016/j.jhazmat.2019.02.039] [Citation(s) in RCA: 33] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/26/2018] [Revised: 02/06/2019] [Accepted: 02/11/2019] [Indexed: 05/26/2023]
Abstract
In this study magnetic Prussian blue (MPB) was synthesized and applied as sorbent for the efficient removal of heavy metals (Cu (II), Co (II), Ni (II) and Pb (II)) from aqueous solution. The average diameter of nanoparticles was found to be about 15 nm. The experimental results were fitted to Langmuir, Freundlich and Dubinin-Radushkevich models with high regression coefficients. The kinetics data were expressed by pseudo-first-order, pseudo-second-order and intraparticle diffusion models. The influence of initial concentration, sorbent dosage and time on the heavy metals sorption efficiency was studied using response surface methodology (RSM). Analysis of variance (ANOVA) was included to assess the adequacy of the model.
Collapse
Affiliation(s)
- I Uogintė
- Center for Physical Sciences and Technology, Savanorių ave. 231, LT-02300 Vilnius, Lithuania.
| | - G Lujanienė
- Center for Physical Sciences and Technology, Savanorių ave. 231, LT-02300 Vilnius, Lithuania
| | - K Mažeika
- Center for Physical Sciences and Technology, Savanorių ave. 231, LT-02300 Vilnius, Lithuania
| |
Collapse
|
38
|
Ciesielczyk F, Żółtowska-Aksamitowska S, Jankowska K, Zembrzuska J, Zdarta J, Jesionowski T. The role of novel lignosulfonate-based sorbent in a sorption mechanism of active pharmaceutical ingredient: batch adsorption tests and interaction study. ADSORPTION 2019. [DOI: 10.1007/s10450-019-00099-1] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
|
39
|
Demirbas O, Calimli MH, Kuyuldar E, Alma MH, Nas MS, Sen F. Equilibrium, Kinetics, and Thermodynamic of Adsorption of Enzymes on Diatomite Clay Materials. BIONANOSCIENCE 2019. [DOI: 10.1007/s12668-019-00615-1] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/23/2023]
|
40
|
Sun C, Chen T, Huang Q, Wang J, Lu S, Yan J. Enhanced adsorption for Pb(II) and Cd(II) of magnetic rice husk biochar by KMnO 4 modification. ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH INTERNATIONAL 2019; 26:8902-8913. [PMID: 30715697 DOI: 10.1007/s11356-019-04321-z] [Citation(s) in RCA: 22] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/13/2018] [Accepted: 01/22/2019] [Indexed: 05/22/2023]
Abstract
Novel KMnO4-treated magnetic biochar (FMBC) was successfully synthesized by addition of Fe(NO3)3 during carbonization and KMnO4 treatment following for Pb(II) and Cd(II) adsorption. SEM-EDS, XPS, and ICP-AES were used to evaluate the FMBC and magnetic biochar (FBC) on surface morphology, surface chemistry characteristics, surface functional groups, and Pb(II) and Cd(II) adsorption behavior. Results showed that the Langmuir maximum adsorption quantity of FMBC reached 148 mg/g for Pb(II) and 79 mg/g for Cd(II), nearly 7 times of that of FBC. The enhancement of FMBC for heavy metal adsorption was due to the successful load of manganese oxides and the increased oxygen functional groups consistent with XPS and FTIR results. The adsorption capacities of FMBC were maintained over 95% when the pH value was higher than 2.5 and 3.5 for Pb(II) and Cd(II), respectively. The adsorption performances of both heavy metals by FMBC were hardly influenced by ionic strength and humid acid. The adsorption capacities of FMBC could maintain over 50% and 87% after four cycles for Pb(II) and Cd(II), respectively. The saturation magnetization of FMBC was about 11.5 emu/g, which did not change after adsorption. This work proposed a new method to fabricate a magnetic biochar with high adsorption capacities of heavy metals Pb(II) and Cd(II).
Collapse
Affiliation(s)
- Chen Sun
- State Key Laboratory of Clean Energy Utilization, Zhejiang University, Hangzhou, 310027, China
| | - Tong Chen
- State Key Laboratory of Clean Energy Utilization, Zhejiang University, Hangzhou, 310027, China.
| | - Qunxing Huang
- State Key Laboratory of Clean Energy Utilization, Zhejiang University, Hangzhou, 310027, China
| | - Jun Wang
- Everbright Envirotech (China) Ltd. Institute of Incineration Technology, Nanjing, 211106, China
| | - Shengyong Lu
- State Key Laboratory of Clean Energy Utilization, Zhejiang University, Hangzhou, 310027, China
| | - Jianhua Yan
- State Key Laboratory of Clean Energy Utilization, Zhejiang University, Hangzhou, 310027, China
| |
Collapse
|
41
|
Formation of Palygorskite Clay from Treated Diatomite and its Application for the Removal of Heavy Metals from Aqueous Solution. WATER 2018. [DOI: 10.3390/w10091257] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Environmental contamination by toxic heavy metals is a serious worldwide phenomenon. Thus, their removal is a crucial issue. In this study, we found an efficient adsorbent to remove Cu2+ and Ni2+ from aqueous solution using two materials. Chemical modification was used to obtain palygorskite clay from diatomite. The adsorbents were characterized using X-ray florescence, Fourier transform infrared spectroscopy and X-ray diffraction. The effects of contact time, initial concentration, temperature and pH on the adsorption process were investigated. Our results showed that the (%) of maximum adsorption capacity of diatomite was 78.44% for Cu2+ at pH 4 and 77.3% for Ni2+ at pH 7, while the (%) of the maximum adsorption on palygorskite reached 91% for Cu2+ and 87.05% for Ni2+, in the same condition. The results indicate that the pseudo-second-order model can describe the adsorption process. Furthermore, the adsorption isotherms could be adopted by the Langmuir and the Freundlich models with good correlation coefficient (R2). Thus, our results showed that palygorskite prepared from Tunisian diatomite is a good adsorbent for the removal of heavy metals from water.
Collapse
|
42
|
Shi W, Lü C, He J, En H, Gao M, Zhao B, Zhou B, Zhou H, Liu H, Zhang Y. Nature differences of humic acids fractions induced by extracted sequence as explanatory factors for binding characteristics of heavy metals. ECOTOXICOLOGY AND ENVIRONMENTAL SAFETY 2018; 154:59-68. [PMID: 29454987 DOI: 10.1016/j.ecoenv.2018.02.013] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/04/2017] [Revised: 02/01/2018] [Accepted: 02/02/2018] [Indexed: 06/08/2023]
Abstract
The composition and structure of Humic acid (HA) is so heterogeneous that it brings significant barriers to investigate the interaction between HA and heavy metal ions. The isolation of HA with relatively homogeneity is a key to reveal the binding mechanisms between HA and heavy metals. In this work, ten HA fractions (HAs) were obtained by sequential alkali extraction procedure and nature differences of the extracted HAs were considered as explanatory factors for binding characteristics of Cu2+, Pb2+ and Cd2+. The results indicate that more large molecular weight (MW) HA subunits, less carboxyl and phenolic group contents, weaker aromaticity and polarity were measured with increasing extractions, inducing weaker binding capacity of HAs. Ligand binding and bi-Langmuir models indicated that the sorption capacity and binding affinity of earlier extracted HAs were higher than the latter ones. The peak area changes at 3427, 1599, and 619 cm-1 pre- and post-adsorption in FTIR spectra suggested carboxyl, phenolic and nitrogen-containing groups were involved in the adsorption process. At the same time, the peak area difference between HAs and HAs-metal (ΔS) of phenolic groups were 8.22-20.50, 6.81-21.11 and 10.66-19.80% for Cu2+, Pb2+ and Cd2+, respectively, ΔS of carboxyl groups 6.64-17.03, 8.96-16.82 and 9.45-17.85% for Cu2+, Pb2+ and Cd2+, respectively, ΔS of nitrogen-containing groups 0.33-0.48, 0.20-1.38 and 0.31-0.59% for Cu2+, Pb2+ and Cd2+, respectively. ΔS of phenolic and carboxyl groups were larger than those of nitrogen-containing groups, implying that these two groups were the predominant binding sites suppliers for metal ions, which were also supported by the results of correlation analysis. This work is helpful to insight the environmental impacts of natural organic matter and the fate of heavy metals in natural environment.
Collapse
Affiliation(s)
- Wenjing Shi
- School of Ecology and Environment, Inner Mongolia University, Hohhot 010021, China
| | - Changwei Lü
- School of Ecology and Environment, Inner Mongolia University, Hohhot 010021, China; Institute of Environmental Geology, Inner Mongolia University, Hohhot 010021, China.
| | - Jiang He
- School of Ecology and Environment, Inner Mongolia University, Hohhot 010021, China; Institute of Environmental Geology, Inner Mongolia University, Hohhot 010021, China.
| | - He En
- School of Ecology and Environment, Inner Mongolia University, Hohhot 010021, China
| | - Manshu Gao
- School of Ecology and Environment, Inner Mongolia University, Hohhot 010021, China
| | - Boyi Zhao
- School of Ecology and Environment, Inner Mongolia University, Hohhot 010021, China
| | - Bin Zhou
- Tianjin Academy of Environmental Sciences, Tianjin 300191, China
| | - Haijun Zhou
- School of Ecology and Environment, Inner Mongolia University, Hohhot 010021, China
| | - Hualin Liu
- Institute of Water Research for Pastoral Area, Ministry of Water Resources, Hohhot 010020, China
| | - Yu Zhang
- College of Animal Science, Inner Mongolia Agricultural University, Hohhot 010010, China
| |
Collapse
|
43
|
Ji S, Miao C, Liu H, Feng L, Yang X, Guo H. A Hydrothermal Synthesis of Fe 3O 4@C Hybrid Nanoparticle and Magnetic Adsorptive Performance to Remove Heavy Metal Ions in Aqueous Solution. NANOSCALE RESEARCH LETTERS 2018; 13:178. [PMID: 29900488 PMCID: PMC5999597 DOI: 10.1186/s11671-018-2580-8] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/24/2018] [Accepted: 05/24/2018] [Indexed: 05/12/2023]
Abstract
Advanced core-shelled material with a high specific area has been considered as an effective material to remove heavy metal from aqueous solutions. A core-shelled Fe3O4@C hybrid nanoparticle aggregates with environmental-friendly channel in the study. Moreover, the higher exposure of adsorption sites can be achieved for the special configuration that higher Brunauer-Emmet-Teller (BET) surface area reaches up to 238.18 m2 g-1. Thus, a more efficiently heavy metal ion removal is obtained, Pb (II), Cd (II), Cu (II), and Cr (VI) up to 100, 99.2, 96.6, and 94.8%, respectively. In addition, the products are easy to be separated from the aqueous solutions after adsorption, due to the relative large submicrometer size and the enhanced external magnetic fields introduced by the iron-based cores. We provide an ideal mode to remove heavy metal ions using core-shelled Fe3O4@C under the water treatment condition. A new approach is clarified that core-shell nano/micro-functional materials can be synthesized well on large scales which are used in many fields such as environmental remediation, catalyst, and energy.
Collapse
Affiliation(s)
- Siping Ji
- School of Chemistry Science and Engineering, Yunnan University, No. 2, CuiHu North Road, Kunming, 650091 China
- Joint Research Centre for International Cross-border Ethnic Regions Biomass Clean Utilization in Yunnan, Yunnan University of Nationalities, Kunming, 650500 China
| | - Changlin Miao
- School of Chemistry Science and Engineering, Yunnan University, No. 2, CuiHu North Road, Kunming, 650091 China
| | - Hui Liu
- School of Chemistry Science and Engineering, Yunnan University, No. 2, CuiHu North Road, Kunming, 650091 China
| | - Lili Feng
- Joint Research Centre for International Cross-border Ethnic Regions Biomass Clean Utilization in Yunnan, Yunnan University of Nationalities, Kunming, 650500 China
| | - Xiangjun Yang
- School of Chemistry Science and Engineering, Yunnan University, No. 2, CuiHu North Road, Kunming, 650091 China
| | - Hong Guo
- School of Chemistry Science and Engineering, Yunnan University, No. 2, CuiHu North Road, Kunming, 650091 China
| |
Collapse
|
44
|
A PTA@MIL-101(Cr)-diatomite composite as catalyst for efficient oxidative desulfurization. INORG CHEM COMMUN 2018. [DOI: 10.1016/j.inoche.2017.11.008] [Citation(s) in RCA: 30] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
|
45
|
Liu G, Mei H, Zhu H, Fang M, Alharbi NS, Hayat T, Chen C, Tan X. Investigation of U(VI) sorption on silica aerogels: Effects of specific surface area, pH and coexistent electrolyte ions. J Mol Liq 2017. [DOI: 10.1016/j.molliq.2017.09.066] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023]
|
46
|
Ling LL, Liu WJ, Zhang S, Jiang H. Magnesium Oxide Embedded Nitrogen Self-Doped Biochar Composites: Fast and High-Efficiency Adsorption of Heavy Metals in an Aqueous Solution. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2017; 51:10081-10089. [PMID: 28753301 DOI: 10.1021/acs.est.7b02382] [Citation(s) in RCA: 162] [Impact Index Per Article: 23.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/27/2023]
Abstract
Lead (Pb) pollution in natural water bodies is an environmental concern due to toxic effects on aquatic ecosystems and human health, while adsorption is an effective approach to remove Pb from the water. Surface interactions between adsorbents and adsorbates play a dominant role in the adsorption process, and properly engineering a material's surface property is critical to the improvement of adsorption performance. In this study, the magnesium oxide (MgO) nanoparticles stabilized on the N-doped biochar (MgO@N-biochar) were synthesized by one-pot fast pyrolysis of an MgCl2-loaded N-enriched hydrophyte biomass as a way to increase the exchangeable ions and N-containing functional groups and facilitate the adsorption of Pb2+. The as-synthesized MgO@N-biochar has a high performance with Pb in an aqueous solution with a large adsorption capacity (893 mg/g), a very short equilibrium time (<10 min), and a large throughput (∼4450 BV). Results show that this excellent adsorption performance can be maintained with various environmentally relevant interferences including pH, natural organic matter, and other metal ions, suggesting that the material may be suitable for the treatment of wastewater, natural bodies of water, and even drinking water. In addition, MgO@N-biochar quickly and efficiently removed Cd2+ and tetracycline. Multiple characterizations and comparative tests have been performed to demonstrate the surface adsorption and ion exchange contributed to partial Pb adsorption, and it can be inferred from these results that the high performance of MgO@N-biochar is mainly due to the surface coordination of Pb2+ and C═O or O═C-O, pyridinic, pyridonic, and pyrrolic N. This work suggests that engineering surface functional groups of biochar may be crucial for the development of high performance heavy metal adsorbents.
Collapse
Affiliation(s)
- Li-Li Ling
- CAS Key Laboratory of Urban Pollutant Conversion, Department of Chemistry, University of Science and Technology of China , Hefei 230026, China
| | - Wu-Jun Liu
- CAS Key Laboratory of Urban Pollutant Conversion, Department of Chemistry, University of Science and Technology of China , Hefei 230026, China
| | - Shun Zhang
- CAS Key Laboratory of Urban Pollutant Conversion, Department of Chemistry, University of Science and Technology of China , Hefei 230026, China
| | - Hong Jiang
- CAS Key Laboratory of Urban Pollutant Conversion, Department of Chemistry, University of Science and Technology of China , Hefei 230026, China
| |
Collapse
|
47
|
Nosrati A, Larsson M, Lindén JB, Zihao Z, Addai-Mensah J, Nydén M. Polyethyleneimine functionalized mesoporous diatomite particles for selective copper recovery from aqueous media. ACTA ACUST UNITED AC 2017. [DOI: 10.1016/j.minpro.2017.07.001] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
|
48
|
Effect of various environmental factors on the adsorption of U(VI) onto biochar derived from rice straw. J Radioanal Nucl Chem 2017. [DOI: 10.1007/s10967-017-5414-8] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023]
|
49
|
Du Y, Wang J, Zou Y, Yao W, Hou J, Xia L, Peng A, Alsaedi A, Hayat T, Wang X. Synthesis of molybdenum disulfide/reduced graphene oxide composites for effective removal of Pb(II) from aqueous solutions. Sci Bull (Beijing) 2017; 62:913-922. [PMID: 36659461 DOI: 10.1016/j.scib.2017.05.025] [Citation(s) in RCA: 55] [Impact Index Per Article: 7.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2017] [Revised: 05/12/2017] [Accepted: 05/18/2017] [Indexed: 01/21/2023]
Abstract
In this work, a facile method was adopted to synthesize molybdenum disulfide/reduced graphene oxide (MoS2/rGO) composites through an l-cysteine-assisted hydrothermal technique. The as-prepared MoS2/rGO composites were firstly applied as adsorbents for efficient elimination of Pb(II) ions. Batch adsorption experiments showed that the adsorption of Pb(II) on MoS2/rGO followed pseudo-second-order kinetic model well. The adsorption of Pb(II) was intensely pH-dependent, ionic strength-dependent at pH < 9.0 and ionic strength-independent at pH > 9.0. The presence of humic acid (HA) enhanced Pb(II) adsorption obviously. The MoS2/rGO composites exhibited excellent adsorption capacity of 384.16mgg-1 at pH 5.0 and T=298.15K, which was superior to MoS2 (279.93mgg-1) and many other adsorbents. The thermodynamic parameters suggested that the adsorption process of Pb(II) on MoS2/rGO composites was spontaneous (ΔGθ<0) and endothermic (ΔHθ>0). The interaction of Pb(II) and MoS2/rGO was mainly dominated by electrostatic attraction and surface complexation between Pb(II) and oxygen-containing functional groups of MoS2/rGO. This work highlighted the application of MoS2/rGO as novel and promising materials in the efficient elimination of Pb(II) from contaminated water and industrial effluents in environmental pollution management.
Collapse
Affiliation(s)
- Yi Du
- College of Environmental Science and Engineering, North China Electric Power University, Beijing 102206, China; School of Nuclear Science and Technology, University of South China, Hengyang 421001, China
| | - Jian Wang
- College of Environmental Science and Engineering, North China Electric Power University, Beijing 102206, China
| | - Yidong Zou
- College of Environmental Science and Engineering, North China Electric Power University, Beijing 102206, China
| | - Wen Yao
- College of Environmental Science and Engineering, North China Electric Power University, Beijing 102206, China
| | - Jing Hou
- College of Environmental Science and Engineering, North China Electric Power University, Beijing 102206, China.
| | - Liangshu Xia
- School of Nuclear Science and Technology, University of South China, Hengyang 421001, China
| | - Anguo Peng
- School of Nuclear Science and Technology, University of South China, Hengyang 421001, China.
| | - Ahmed Alsaedi
- NAAM Research Group, Faculty of Science, King Abdulaziz University, Jeddah 21589, Saudi Arabia
| | - Tasawar Hayat
- NAAM Research Group, Faculty of Science, King Abdulaziz University, Jeddah 21589, Saudi Arabia
| | - Xiangke Wang
- College of Environmental Science and Engineering, North China Electric Power University, Beijing 102206, China; School of Nuclear Science and Technology, University of South China, Hengyang 421001, China; NAAM Research Group, Faculty of Science, King Abdulaziz University, Jeddah 21589, Saudi Arabia; Collaborative Innovation Center of Radiation Medicine of Jiangsu Higher Education Institutions, School for Radiological and Interdisciplinary Sciences, Soochow University, Suzhou 215123, China.
| |
Collapse
|
50
|
Han H, Cheng C, Hu S, Li X, Wang W, Xiao C, Xu Z, Shao D. Facile synthesis of gelatin modified attapulgite for the uptake of uranium from aqueous solution. J Mol Liq 2017. [DOI: 10.1016/j.molliq.2017.03.076] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
|