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Zhang L, Zhou J, Xiong J. Sulfoaluminate cement-modified loess as bioretention cell filler for nutrient removal from stormwater runoff. ENVIRONMENTAL RESEARCH 2024; 261:119704. [PMID: 39074772 DOI: 10.1016/j.envres.2024.119704] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/19/2024] [Revised: 07/22/2024] [Accepted: 07/27/2024] [Indexed: 07/31/2024]
Abstract
In order to reduce the consumption of sand and gravel resources, the use of loess can reduce transportation costs and realize the in-situ construction of spongy in areas with rich loess resources. But the collapsibility and low permeability of loess make it unable to be directly used as the filler of bioretention cells. In this study, sulfoaluminate cement (SAC) mixed with a small amount of basalt fiber was considered to be used for loess modification, and the physicochemical properties and nutrient removal effect of SAC-modified loess as filler in bioretention cells were comprehensively evaluated. The results showed that when the SAC dosage was 15% and the basalt fiber addition was 0% (S15B0) and 0.6% (S15B6) and the curing time was 14 days, the stability and appropriate permeability can be exhibited, which can preliminarily satisfy the requirements of bioretention cell. SAC made the maximum adsorption capacity of S15B0 and S15B6 for ammonia nitrogen (NH4+-N) and phosphate higher than that of sand by 10.96%-31.51% and 45.92%-76.72%, respectively. The hydration products in SAC modified loess can fill the internal pores of loess particles and provide structural support, and ultimately reduce the accumulated pores, mesoporous pore size (20%) and surface homogeneity. Both S15B0 and S15B6 showed good removal effects of NH4+-N and COD. The TP removal efficiency was stable at 95.43%∼99.95%. Both the antecedent drying days and the submerged zone have an effect on the nitrogen removal in the bioretention cells, where a longer antecedent drying days is detrimental to the nitrogen removal, and the installation of a submerged zone improves the nitrogen removal. The basalt fiber can enhance the transformation process from nitrate-nitrogen to nitrite-nitrogen in the bioretention cell. Therefore, the modification of SAC can provide a certain idea for the in-situ use of loess as the filler of the bioretention cell.
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Affiliation(s)
- Liyu Zhang
- Key Lab of Northwest Water Resource, Environment and Ecology, MOE, Xi'an University of Architecture and Technology, Xi'an, 710055, PR China; School of Environmental and Municipal Engineering, Xi'an University of Architecture and Technology, Yan Ta Road. No.13, Xi'an, 710055, PR China
| | - Jiajia Zhou
- Key Lab of Northwest Water Resource, Environment and Ecology, MOE, Xi'an University of Architecture and Technology, Xi'an, 710055, PR China; School of Environmental and Municipal Engineering, Xi'an University of Architecture and Technology, Yan Ta Road. No.13, Xi'an, 710055, PR China
| | - Jiaqing Xiong
- Key Lab of Northwest Water Resource, Environment and Ecology, MOE, Xi'an University of Architecture and Technology, Xi'an, 710055, PR China; School of Environmental and Municipal Engineering, Xi'an University of Architecture and Technology, Yan Ta Road. No.13, Xi'an, 710055, PR China.
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2
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Wen B, Li A, Zhao J, Guo H, Fang Y, Lin Y, Cheng HB. Facile Assembly Strategy for Luminescent Lanthanide Nanoparticles with Antibacterial Activity Using Aggregation-Inducing Emission Polymers. Macromolecules 2023. [DOI: 10.1021/acs.macromol.2c02445] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/26/2023]
Affiliation(s)
- Boxin Wen
- State Key Laboratory of Organic−Inorganic Composites, Beijing Laboratory of Biomedical Materials, College of Materials Science and Engineering, Beijing University of Chemical Technology, 15 North Third Ring Road, Beijing 100029, P. R. China
| | - Ang Li
- State Key Laboratory of Organic−Inorganic Composites, Beijing Laboratory of Biomedical Materials, College of Materials Science and Engineering, Beijing University of Chemical Technology, 15 North Third Ring Road, Beijing 100029, P. R. China
| | - Jing Zhao
- State Key Laboratory of Organic−Inorganic Composites, Beijing Laboratory of Biomedical Materials, College of Materials Science and Engineering, Beijing University of Chemical Technology, 15 North Third Ring Road, Beijing 100029, P. R. China
| | - Haodan Guo
- Key Laboratory of Photochemistry, Beijing National Laboratory for Molecular Sciences, CAS Research Education Center for Excellence in Molecular Sciences, Institute of Chemistry, Chinese Academy of Sciences, Beijing 100029, P. R. China
| | - Yanyan Fang
- Key Laboratory of Photochemistry, Beijing National Laboratory for Molecular Sciences, CAS Research Education Center for Excellence in Molecular Sciences, Institute of Chemistry, Chinese Academy of Sciences, Beijing 100029, P. R. China
| | - Yuan Lin
- Key Laboratory of Photochemistry, Beijing National Laboratory for Molecular Sciences, CAS Research Education Center for Excellence in Molecular Sciences, Institute of Chemistry, Chinese Academy of Sciences, Beijing 100029, P. R. China
| | - Hong-Bo Cheng
- State Key Laboratory of Organic−Inorganic Composites, Beijing Laboratory of Biomedical Materials, College of Materials Science and Engineering, Beijing University of Chemical Technology, 15 North Third Ring Road, Beijing 100029, P. R. China
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3
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Moazami S, Kharaziha M, Emadi R, Dinari M. Multifunctional Bioinspired Bredigite-Modified Adhesive for Bone Fracture Healing. ACS APPLIED MATERIALS & INTERFACES 2023; 15:6499-6513. [PMID: 36700731 DOI: 10.1021/acsami.2c20038] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/17/2023]
Abstract
Despite recent advances in bone adhesives applied for full median sternotomy, the regeneration of bone defects has remained challenging since the healing process is hampered by poor adhesiveness, limited bioactivity, and lack of antibacterial functions. Bioinspired adhesives by marine organisms provide a novel concept to circumvent these problems. Herein, a dual cross-link strategy is employed in designing a multifaceted bioinspired adhesive consisting of a catechol amine-functionalized hyperbranched polymer (polydopamine-co-acrylate, PDA), bredigite (BR) nanoparticles, and Fe3+ ions. The hybrid adhesives exhibit strong adhesion to various substrates such as poly(methyl methacrylate), glass, bone, and skin tissues through synergy between irreversible covalent and reversible noncovalent cross-linking, depending on the BR content. Noticeably, the adhesion strength of hybrid adhesives containing 2 wt % BR nanoparticles to bone tissues is 2.3 ± 0.8 MPa, which is about 3 times higher than that of pure PDA adhesives. We also demonstrate that these hybrid adhesives not only are bioactive and accelerate in vitro bone-like apatite formation but also exhibit antibacterial properties against Staphylococcus aureus, depending on the BR concentration. Furthermore, the superior cellular responses in contact with hybrid adhesives, including improved human osteosarcoma MG63 cell spreading and osteogenic differentiation, are achieved owing to the appropriate ion release and flexibility of the cross-linked double-network adhesive. In summary, multifunctional hybrid PDA/BR adhesives with appreciable osteoconductive, mechanical, and antibacterial properties represent the potential applications for median sternotomy surgery as a bone tissue adhesive.
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Affiliation(s)
- Shima Moazami
- Department of Materials Engineering, Isfahan University of Technology, Isfahan84156-83111, Iran
| | - Mahshid Kharaziha
- Department of Materials Engineering, Isfahan University of Technology, Isfahan84156-83111, Iran
| | - Rahmatallah Emadi
- Department of Materials Engineering, Isfahan University of Technology, Isfahan84156-83111, Iran
| | - Mohammad Dinari
- Department of Chemistry, Isfahan University of Technology, Isfahan84156-83111, Iran
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4
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Zhu X, Liu J, Li L, Zhen G, Lu X, Zhang J, Liu H, Zhou Z, Wu Z, Zhang X. Prospects for humic acids treatment and recovery in wastewater: A review. CHEMOSPHERE 2023; 312:137193. [PMID: 36370766 DOI: 10.1016/j.chemosphere.2022.137193] [Citation(s) in RCA: 10] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/30/2022] [Revised: 10/26/2022] [Accepted: 11/05/2022] [Indexed: 06/16/2023]
Abstract
Clean water shortages require the reuse of wastewater. The presence of organic substances such as humic acids in wastewater makes the water treatment process more difficult. Humic acids can significantly affect the removal of heavy metals and other such toxins. Humic acids is formed by the decomposition and transformation of animal and plant remains by microorganisms, and naturally exists in soil and water. It is necessary to degrade and remove humic acids from wastewater. As it seriously human health, effective technologies for removing humic acids from wastewater have attracted great interest over the past decades. This study compared existing techniques for removing humic acids from wastewater, as well as their limitations. Physicochemical treatments including filtration and oxidation are basic and key approaches to removing humic acids. Biological treatments including enzyme and fungi-mediated humic acids degradation are economically feasible but require some scalability. In conclusion, the integrated treatment processes are more significant options for the effective removal of humic acids from wastewater. In addition, humic acids have rich utilization values. It can improve the soil, increase crop yields, and promote the removal of pollutants.
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Affiliation(s)
- Xuefeng Zhu
- School of Environment and Architecture, University of Shanghai for Science and Technology, Shanghai, 200093, PR China.
| | - Jiadong Liu
- School of Environment and Architecture, University of Shanghai for Science and Technology, Shanghai, 200093, PR China
| | - Liang Li
- School of Environment and Architecture, University of Shanghai for Science and Technology, Shanghai, 200093, PR China
| | - Guangyin Zhen
- Shanghai Key Lab for Urban Ecological Processes and Eco-Restoration, School of Ecological and Environmental Sciences, East China Normal University, Shanghai, 200241, PR China
| | - Xueqin Lu
- Shanghai Key Lab for Urban Ecological Processes and Eco-Restoration, School of Ecological and Environmental Sciences, East China Normal University, Shanghai, 200241, PR China
| | - Jie Zhang
- State Key Laboratory of Pollution Control and Resource Reuse, College of Environmental Science and Engineering, Tongji University, Shanghai, 200092, PR China
| | - Hongbo Liu
- School of Environment and Architecture, University of Shanghai for Science and Technology, Shanghai, 200093, PR China.
| | - Zhen Zhou
- College of Environmental and Chemical Engineering, Shanghai University of Electric Power, Shanghai, 200090, PR China
| | - Zhichao Wu
- State Key Laboratory of Pollution Control and Resource Reuse, College of Environmental Science and Engineering, Tongji University, Shanghai, 200092, PR China
| | - Xuedong Zhang
- Department of Environmental Engineering, Faculty of Environment and Civil Engineering, Jiangnan University, Wuxi, 214122, PR China.
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5
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Floc formation and growth during coagulation removing humic acid: Effect of stirring condition. Sep Purif Technol 2022. [DOI: 10.1016/j.seppur.2022.122084] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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6
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Gomes BFML, de Araújo CMB, do Nascimento BF, Freire EMPDL, Da Motta Sobrinho MA, Carvalho MN. Synthesis and application of graphene oxide as a nanoadsorbent to remove Cd (II) and Pb (II) from water: adsorption equilibrium, kinetics, and regeneration. ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH INTERNATIONAL 2022; 29:17358-17372. [PMID: 34664163 DOI: 10.1007/s11356-021-16943-3] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/12/2021] [Accepted: 10/04/2021] [Indexed: 06/13/2023]
Abstract
In this work, graphene oxide (GO) was synthesized by the modified Hummers method. The nanomaterial was characterized by FTIR and Raman spectroscopy, SEM, and pH at the point of zero charge. GO exhibited typical characteristics of graphene-based materials, indicating that graphite oxidation and exfoliation occurred successfully. Cd (II) and Pb (II) adsorption onto GO was carried out in batch systems, in which the effect of adsorbent dosage, contact time, and initial adsorbate concentration were evaluated. Langmuir, Freundlich, and Sips isotherm models, as well as pseudo order models and Elovich kinetic equation were applied to adsorption experimental data. Results indicated that increasing adsorbent mass, the removal efficiency of Cd (II) and Pb (II) increased. Freundlich isotherm better described Pb (II) adsorption (R2 = 0.96), while Cd (II) isotherm showed linear behavior. From the Akaike's AIC parameter, kinetic data were satisfactorily described by pseudo-first order (Cd (II)) and pseudo-n order (Pb (II)) models. GO was successfully subjected to five regeneration cycles, maintaining high efficiency (> 90%) in all cycles. GO showed high potential for the adsorption of Cd (II) and Pb (II) from aqueous solution, due to its high adsorption capacity, rapid Cd (II) and Pb (II) intakes, and great regeneration performance.
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Affiliation(s)
- Brener Felipe Melo Lima Gomes
- Department of Rural Technology, Universidade Federal Rural de Pernambuco, R. Dom Manuel de Medeiros, Recife, PE, 52171-900, Brazil.
| | - Caroline Maria Bezerra de Araújo
- Department of Chemical Engineering, Universidade Federal de Pernambuco, Av. Prof. Moraes Rego 1235, Recife, PE, 50670-910, Brazil
| | - Bruna Figueiredo do Nascimento
- Department of Chemical Engineering, Universidade Federal de Pernambuco, Av. Prof. Moraes Rego 1235, Recife, PE, 50670-910, Brazil
| | | | - Mauricio Alves Da Motta Sobrinho
- Department of Chemical Engineering, Universidade Federal de Pernambuco, Av. Prof. Moraes Rego 1235, Recife, PE, 50670-910, Brazil
| | - Marilda Nascimento Carvalho
- Department of Chemical Engineering, Universidade Federal de Pernambuco, Av. Prof. Moraes Rego 1235, Recife, PE, 50670-910, Brazil
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7
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Maki H, Baba K, Oh Y, Mizuhata M. Analysis of hydrolysis reaction of aluminum polynuclear complex with Cl− and SO42− anions by quantitative multinuclear NMR and evaluation of coagulation behavior of model sludge water. Colloids Surf A Physicochem Eng Asp 2021. [DOI: 10.1016/j.colsurfa.2021.127623] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
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8
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Flocculation properties of eight microalgae induced by aluminum chloride, chitosan, amphoteric polyacrylamide, and alkaline: Life-cycle assessment for screening species and harvesting methods. ALGAL RES 2021. [DOI: 10.1016/j.algal.2021.102226] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
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9
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Wu Z, Zhang X, Pang J, Zhang X, Li J, Li J, Zhang P. Humic Acid Removal from Water with PAC-Al 30: Effect of Calcium and Kaolin and the Action Mechanisms. ACS OMEGA 2020; 5:16413-16420. [PMID: 32685804 PMCID: PMC7364432 DOI: 10.1021/acsomega.0c00532] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 02/06/2020] [Accepted: 06/19/2020] [Indexed: 06/11/2023]
Abstract
Polyaluminum chloride with a dominant species of Al30 (PAC-Al30) was prepared in laboratory and used for humic acid (HA) removal from water. The action properties and mechanisms of PAC-Al30, HA, calcium, and kaolin were tested and discussed. The results showed that the existence of calcium or kaolin contributed to the HA removal when the PAC-Al30 dosage was deficient and had no obvious effect when the amount of PAC-Al30 was sufficient. When the PAC-Al30 dosage was 0.01 and 0.02 mmol/L, the HA removal rate was increased by 66.59 and 42.20%, respectively, with a calcium concentration of 2.0 mmol/L, or increased by 53.31 and 40.92%, respectively, with the kaolin particle concentration of 150 mg/L. Calcium could compress the double electrical layers or complex with HA to neutralize a part of the surface negative charge of HA, but could not make the water system reach its isoelectric point. The mechanisms of calcium and kaolin's promoting coagulation effect were adsorption neutralization and collision aggregation respectively, but these actions were much weaker than that of PAC-Al30 with HA. The adsorption neutralization capacity of PAC-Al30 was calculated to be nearly 60 times than that of calcium, and the higher γ value of calcium modified by the Sips equation may indicate that the adsorption or neutralization sites of calcium on HA were pickier than PAC-Al30.
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Affiliation(s)
- Zhen Wu
- Department
of Chemical Engineering, Ordos Institute
of Technology, Ordos 017000, China
- Department
of Water Resources & Environmental Treatment, Redbud Innovation Institute, Ordos 017000, China
| | - Xian Zhang
- Department
of Chemical Engineering, Ordos Institute
of Technology, Ordos 017000, China
- Department
of Water Resources & Environmental Treatment, Redbud Innovation Institute, Ordos 017000, China
| | - Jinglin Pang
- Department
of Water Resources & Environmental Treatment, Redbud Innovation Institute, Ordos 017000, China
| | - Xianming Zhang
- Department
of Water Resources & Environmental Treatment, Redbud Innovation Institute, Ordos 017000, China
| | - Juan Li
- College
of Environmental Science and Engineering, Beijing Forestry University, Beijing 100083, China
| | - Jiding Li
- Department
of Chemical Engineering, Tsinghua University, Beijing 100084, China
| | - Panyue Zhang
- College
of Environmental Science and Engineering, Beijing Forestry University, Beijing 100083, China
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10
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Gong S, He T, Huang Q, Shu X, Zhou X. Anchoring PNIPAM on ATP Surface via hydrogen bonding and coordination for a temperature-responsive adsorption of hydrophobic drug. SN APPLIED SCIENCES 2020. [DOI: 10.1007/s42452-020-2643-1] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022] Open
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11
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Zhou Q, Chen W, Jiang X, Liu H, Ma S, Wang B. Preparation of a novel nitrogen-containing graphitic mesoporous carbon for the removal of acid red 88. Sci Rep 2020; 10:1353. [PMID: 31992724 PMCID: PMC6987219 DOI: 10.1038/s41598-020-57823-z] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2019] [Accepted: 12/19/2019] [Indexed: 11/10/2022] Open
Abstract
A novel nitrogen-containing graphitic mesoporous carbon was prepared through MnO-templated method using polyacrylonitrile (PAN) as both carbon and nitrogen sources, and MnCO3 as both template and catalyst precursors. The effects of preparation conditions on the physicochemical properties of obtained samples were systematically investigated. The results showed that as the decrease of the weight ratios of PAN and MnO (2:1-1:4), the increase of carbonization temperature (700-900 °C) and pre-oxidation temperature (180-200 °C), the samples had higher specific surface area, mesopores volume and ratios, up to 507 m2/g, 0.824 cm3/g and 96.83%, respectively. Moreover, the prepared samples presented relatively high graphitic degree and nitrogen contents (~2.21%). The adsorption capacity for acid red 88 (AR88) was as high as 309 mg/g, which were dramatically affected by the mesoporous properties and C- and N-containing groups on the surface of prepared carbon. The rich graphic carbon and pyridine-N in mesoporous carbon generated π-π dispersion and electrostatic interaction with AR88, respectively, which jointly were responsible for the adsorption process. The results of the isotherm and kinetic studies indicated that the AR88 adsorption on mesoporous carbon could be well depicted using Langmuir model and pseudo-2nd-order model.
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Affiliation(s)
- Qiying Zhou
- College of Architecture and Environment, Sichuan University, Chengdu, 610065, China.,National Engineering Research Centre for Flue Gas Desulfurization, Chengdu, 610065, China
| | - Wenhua Chen
- College of Architecture and Environment, Sichuan University, Chengdu, 610065, China.,National Engineering Research Centre for Flue Gas Desulfurization, Chengdu, 610065, China
| | - Xia Jiang
- College of Architecture and Environment, Sichuan University, Chengdu, 610065, China. .,National Engineering Research Centre for Flue Gas Desulfurization, Chengdu, 610065, China.
| | - Hongying Liu
- College of Architecture and Environment, Sichuan University, Chengdu, 610065, China.,National Engineering Research Centre for Flue Gas Desulfurization, Chengdu, 610065, China
| | - Shenggui Ma
- College of Architecture and Environment, Sichuan University, Chengdu, 610065, China.,National Engineering Research Centre for Flue Gas Desulfurization, Chengdu, 610065, China
| | - Bangda Wang
- College of Architecture and Environment, Sichuan University, Chengdu, 610065, China.,National Engineering Research Centre for Flue Gas Desulfurization, Chengdu, 610065, China
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12
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Wu Z, Zhang X, Pang J, Li J, Li J, Zhang P. High-poly-aluminum chloride sulfate coagulants and their coagulation performances for removal of humic acid. RSC Adv 2020; 10:7155-7162. [PMID: 35493884 PMCID: PMC9049776 DOI: 10.1039/c9ra10189f] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2019] [Accepted: 01/21/2020] [Indexed: 12/23/2022] Open
Abstract
High-poly-aluminum chloride sulfate (HPACS) coagulants with different [SO42−]/[Al3+] molar ratio (S) were prepared and proved to have high coagulation efficiency for the removal of humic acid and strong stability for storage and application. The results showed that the higher the SO42− addition, the bigger the aluminum polymerization particles and the more the polymerization Alc existed in the prepared HPACS coagulants. The HPACS exhibited higher coagulation efficiency, a better aging stability and stronger resistance to the change of pH and Ca2+ concentration of raw water than the polyaluminum chloride (PAC) and poly-aluminum chloride sulfate (PACS) reported before. The Sips adsorption neutralization model was established to illustrate the relationship between coagulant dosage and zeta potential of the water system. The adsorption neutralization capacity was proved to be HPACS (S = 0) > HPACS (S = 0.02) > HPACS (S = 0.06) > HPACS (S = 0.10), which was not completely consistent with the coagulation effect of HPACS with different S values and indicated that in addition to adsorption neutralization, actions like bridge-aggregation, precipitation, and sweep-flocculation also played an important role during HPACS coagulation. Moreover, the negative Gibbs free energy indicated that the coagulant adsorption neutralization reaction was a spontaneous process. Effect of aging time of HPACS on HA removal (with a minimum absolute deviation of 5%).![]()
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Affiliation(s)
- Zhen Wu
- Department of Chemical Engineering
- Ordos Institute of Technology
- Ordos 017000
- China
- Department of Water Resources & Environmental Treatment
| | - Xian Zhang
- Department of Chemical Engineering
- Ordos Institute of Technology
- Ordos 017000
- China
- Department of Water Resources & Environmental Treatment
| | - Jinglin Pang
- Department of Chemical Engineering
- Ordos Institute of Technology
- Ordos 017000
- China
| | - Juan Li
- College of Environmental Science and Engineering
- Beijing Forestry University
- Beijing 100083
- China
| | - Jiding Li
- Department of Chemical Engineering
- Tsinghua University
- Beijing 100084
- China
| | - Panyue Zhang
- College of Environmental Science and Engineering
- Beijing Forestry University
- Beijing 100083
- China
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13
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Wang Z, Nan J, Ji X, Yang Y. Effect of the micro-flocculation stage on the flocculation/sedimentation process: The role of shear rate. THE SCIENCE OF THE TOTAL ENVIRONMENT 2018; 633:1183-1191. [PMID: 29758870 DOI: 10.1016/j.scitotenv.2018.03.286] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/05/2018] [Revised: 03/03/2018] [Accepted: 03/23/2018] [Indexed: 06/08/2023]
Abstract
Dynamic analysis on the variation of particle size distribution (PSD) and the fractal characteristics of PSD (Df) were investigated to better understand the continuous procedure of the floc growth and optimize the control of flocculation process. It was found that the flocculation process could be divided into three stages, i.e., the micro-flocculation stage, the growth stage and the steady (or breakage) stage. As the stage which is crucial to the morphology of micro-flocs (the building blocks of large flocs), the micro-flocculation stage plays an important role on flocculation/sedimentation process. The results showed that an increase in shear rate (11s-1<G<30s-1) during the micro-flocculation stage contributed to micro-flocs with larger size and more compact structure. As shear rate further increased (30s-1<G<55s-1), the micro-floc average size gently decreased from 13.61μm to 10.91μm, whereas two-dimension fractal dimension of micro-flocs gradually increased from 1.85 to 1.89. This indicated that further increase of shear rate during the micro-flocculation was incline to the formation of smaller micro-flocs with more compact structure. According to the results of final floc properties, the moderate shear rate (G=30s-1) benefited to the micro-floc formation to form final flocs with desired properties, further improved the treatment efficiency in the whole process. Based on the kinetics in the micro-flocculation stage, a conceptual model was proposed to describe the micro-floc growth under different shear rates, further revealed the reason for the different properties of final flocs under various shear rate during the micro-flocculation stage. Combining the results with model, it was concluded that shear rate during the micro-flocculation stage mainly affected final flocs by the domination of micro-floc structure. This research gives indications both for theoretical and actual works to improve the efficiency in the solid/liquid process.
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Affiliation(s)
- Zhenbei Wang
- State Key Laboratory of Urban Water Resource and Environment, School of Environment, Harbin Institute of Technology, Harbin 150090, People's Republic of China
| | - Jun Nan
- State Key Laboratory of Urban Water Resource and Environment, School of Environment, Harbin Institute of Technology, Harbin 150090, People's Republic of China.
| | - Xiaoyu Ji
- State Key Laboratory of Urban Water Resource and Environment, School of Environment, Harbin Institute of Technology, Harbin 150090, People's Republic of China
| | - Yueming Yang
- State Key Laboratory of Urban Water Resource and Environment, School of Environment, Harbin Institute of Technology, Harbin 150090, People's Republic of China
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14
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Wang W, Yue Q, Li R, Song W, Gao B, Shen X. Investigating coagulation behavior of chitosan with different Al species dual-coagulants in dye wastewater treatment. J Taiwan Inst Chem Eng 2017. [DOI: 10.1016/j.jtice.2017.06.052] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
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