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Huang J, Tan X, Xie Y, Wu X, Dahn SL, Duan Z, Ali I, Cao J, Ruan Y. A new approach to explore and assess the sustainable remediation of chromium-contaminated wastewater by biochar based on 3E model. Chemosphere 2024; 353:141600. [PMID: 38458355 DOI: 10.1016/j.chemosphere.2024.141600] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/02/2024] [Revised: 02/16/2024] [Accepted: 02/29/2024] [Indexed: 03/10/2024]
Abstract
As a cost-effective material, biochar, known as 'black gold', has been widely used for environmental applications (EA), including chromium-contaminated wastewater remediation. However, limited reports focused on the multiple impacts of biochar, including energy consumption (EC) and environmental risk (ER). Hence, to recommend biochar as a green material for sustainable development, the three critical units were explored and quantitatively assessed based on an adapted 3E model (EA-EC-ER). The tested biochar was produced by limited-oxygen pyrolysis at 400-700 °C by using three typical biomasses (Ulva prolifera, phoenix tree, and municipal sludge), and the optimal operational modulus of the 3E model was identified using six key indicators. The findings revealed a significant positive correlation between EC and biochar yield (p < 0.05). The biochar produced by phoenix tree consumed more energy due to having higher content of unstable carbon fractions. Further, high-temperature and low-temperature biochar demonstrated different chromium removal mechanisms. Notably, the biochar produced at low temperature (400 °C) achieved better EA due to having high removal capacity and stability. Regarding ER, pyrolysis temperature of 500 °C could effectively stabilize the ecological risk in all biochar and the biochar produced by Ulva prolifera depicted the greatest reduction (37-fold). However, the increase in pyrolysis temperature would lead to an increase in global warming potential by nearly 22 times. Finally, the 3E model disclosed that the biochar produced by Ulva prolifera at 500 °C with low EC, high EA, and low ER had the most positive recommendation index (+78%). Importantly, a rapid assessment methodology was established by extracting parameters from the correlation. Based on this methodology, about eight percent of biochar can be the highest recommended from more than 100 collected peer-related data. Overall, the obtained findings highlighted that the multiple impacts of biochar should be considered to efficiently advance global sustainable development goals.
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Affiliation(s)
- Jiang Huang
- Key Laboratory of Integrated Regulation and Resource Development on Shallow Lakes, Ministry of Education, College of Environment, Hohai University, Nanjing, 210098, China
| | - Xiao Tan
- Key Laboratory of Integrated Regulation and Resource Development on Shallow Lakes, Ministry of Education, College of Environment, Hohai University, Nanjing, 210098, China.
| | - Yue Xie
- Anhui Province Agricultural Waste Fertilizer Utilization and Cultivated Land Quality Improvement Engineering Research Center, Chuzhou, 233100, China
| | - Xiaoge Wu
- College of Environmental Science and Engineering, Yangzhou University, Yangzhou, Jiangsu, 225009, China
| | - Stephen L Dahn
- Key Laboratory of Integrated Regulation and Resource Development on Shallow Lakes, Ministry of Education, College of Environment, Hohai University, Nanjing, 210098, China
| | - Zhipeng Duan
- Key Laboratory of Integrated Regulation and Resource Development on Shallow Lakes, Ministry of Education, College of Environment, Hohai University, Nanjing, 210098, China
| | - Imran Ali
- Key Laboratory of Integrated Regulation and Resource Development on Shallow Lakes, Ministry of Education, College of Environment, Hohai University, Nanjing, 210098, China
| | - Jun Cao
- National Engineering Research Center of Water Resources Efficient Utilization and Engineering Safety, Hohai University, Nanjing, 210098, China
| | - Yinlan Ruan
- Institute for Photonics and Advanced Sensing, The University of Adelaide, SA 5005, Australia
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2
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Ismail UM, Vohra MS, Onaizi SA. Adsorptive removal of heavy metals from aqueous solutions: Progress of adsorbents development and their effectiveness. Environ Res 2024; 251:118562. [PMID: 38447605 DOI: 10.1016/j.envres.2024.118562] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/31/2023] [Revised: 02/11/2024] [Accepted: 02/25/2024] [Indexed: 03/08/2024]
Abstract
Increased levels of heavy metals (HMs) in aquatic environments poses serious health and ecological concerns. Hence, several approaches have been proposed to eliminate/reduce the levels of HMs before the discharge/reuse of HMs-contaminated waters. Adsorption is one of the most attractive processes for water decontamination; however, the efficiency of this process greatly depends on the choice of adsorbent. Therefore, the key aim of this article is to review the progress in the development and application of different classes of conventional and emerging adsorbents for the abatement of HMs from contaminated waters. Adsorbents that are based on activated carbon, natural materials, microbial, clay minerals, layered double hydroxides (LDHs), nano-zerovalent iron (nZVI), graphene, carbon nanotubes (CNTs), metal organic frameworks (MOFs), and zeolitic imidazolate frameworks (ZIFs) are critically reviewed, with more emphasis on the last four adsorbents and their nanocomposites since they have the potential to significantly boost the HMs removal efficiency from contaminated waters. Furthermore, the optimal process conditions to achieve efficient performance are discussed. Additionally, adsorption isotherm, kinetics, thermodynamics, mechanisms, and effects of varying adsorption process parameters have been introduced. Moreover, heavy metal removal driven by other processes such as oxidation, reduction, and precipitation that might concurrently occur in parallel with adsorption have been reviewed. The application of adsorption for the treatment of real wastewater has been also reviewed. Finally, challenges, limitations and potential areas for improvements in the adsorptive removal of HMs from contaminated waters are identified and discussed. Thus, this article serves as a comprehensive reference for the recent developments in the field of adsorptive removal of heavy metals from wastewater. The proposed future research work at the end of this review could help in addressing some of the key limitations facing this technology, and create a platform for boosting the efficiency of the adsorptive removal of heavy metals.
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Affiliation(s)
- Usman M Ismail
- Department of Civil and Environmental Engineering, King Fahd University of Petroleum and Minerals, Dhahran 31261, Saudi Arabia.
| | - Muhammad S Vohra
- Department of Civil and Environmental Engineering, King Fahd University of Petroleum and Minerals, Dhahran 31261, Saudi Arabia; Interdisciplinary Research Center for Construction and Building Materials, King Fahd University of Petroleum and Minerals, Dhahran 31261, Saudi Arabia
| | - Sagheer A Onaizi
- Department of Chemical Engineering, King Fahd University of Petroleum and Minerals, Dhahran 31261, Saudi Arabia; Interdisciplinary Research Center for Hydrogen and Energy Storage, King Fahd University of Petroleum and Minerals, Dhahran 31261, Saudi Arabia.
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3
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Rashidi F, Larki A, Jafar Saghanezhad S. Cost-effective removal of Cr(VI) ions from aqueous media using L-cysteine functionalized gold nanoparticles embedded in melamine-based covalent organic framework (Cys-AuNPs@COF). Spectrochim Acta A Mol Biomol Spectrosc 2024; 308:123762. [PMID: 38128331 DOI: 10.1016/j.saa.2023.123762] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/17/2023] [Revised: 11/29/2023] [Accepted: 12/10/2023] [Indexed: 12/23/2023]
Abstract
Due to the growing concern about the environmental effects of heavy metals, researchers are developing materials that possess high absorption capacity in addition to selectivity and high absorption speed. Recently, covalent organic frameworks (COFs) have been considered as emerging and promising adsorbents for the removal of many types of pollutants. In this work, a novel and selective adsorbent (Cys-AuNPs@COF) was prepared by embedding gold nanoparticles functionalized with L-cysteine in melamine-based COF for the removal of Cr(VI) ions from wastewater. The synthesized Cys-AuNPs@COF were characterizedby Fourier-transform infrared spectroscopy (FT-IR), X-ray diffraction analysis (XRD), Field emission scanning electron microscopy (FESEM), Energy-dispersive X-ray spectroscopy (EDX), Thermo-gravimetric analysis (TGA), and elemental mapping (EMA) analysis. The removal of Cr(VI) ions was performed using a batch mode process by taking advantage of response surface methodology (RSM) based on a central composite design (CCD) model. The maximum adsorption capacity of Cys-AuNPs@COF was 151.5 mg g-1. The experimental results followed the Langmuir model and showed pseudo-second-order kinetics. A portable, low-cost, and highly sensitive device with a smartphone colorimeter platform was developed for in situ measurement of trace amounts of chromium (VI) ions. Due to its simplicity and versatility, this method has the potential to serve as an alternative to conventional field analysis methods.
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Affiliation(s)
- Fatemeh Rashidi
- Department of Marine Chemistry, Faculty of Marine Science, Khorramshahr University of Marine Science and Technology, Khorramshahr, Iran
| | - Arash Larki
- Department of Marine Chemistry, Faculty of Marine Science, Khorramshahr University of Marine Science and Technology, Khorramshahr, Iran.
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Su K, Hu G, Zhao T, Dong H, Yang Y, Pan H, Lin Q. The ultramicropore biochar derived from waste distiller's grains for wet-process phosphoric acid purification: Removal performance and mechanisms of Cr(VI). Chemosphere 2024; 349:140877. [PMID: 38061559 DOI: 10.1016/j.chemosphere.2023.140877] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/18/2023] [Revised: 11/27/2023] [Accepted: 12/01/2023] [Indexed: 01/10/2024]
Abstract
Solid waste and heavy metal pollution are long-term and challenging subjects in the field of environmental engineering. In this study, we propose a sustainable approach to "treating waste with waste" by utilizing the ultramicropore biochar derived from solid waste distiller's grains as a means to remove Cr(VI) from simulated wastewater and wet phosphoric acid. The biochar prepared in this research exhibit extremely high specific surface areas (up to 2973 m2/g) and a well-developed pore structure, resulting in a maximum Cr(VI) adsorption capacity of 426.0 mg/g and over 99% removal efficiency of Cr(VI). Furthermore, the adsorbent can be reused for up to eight cycles without significant reduction in its Cr(VI) adsorption performance. Mechanistic investigations suggest that the exceptional Cr(VI) adsorption capacity can be attributed to the synergistic effect of electrostatic interaction and reduction adsorption. This study offers an alternative approach for the resource utilization of solid waste distiller's grains, and the prepared biochar holds promise for the removal of Cr(VI) from wastewater and wet-process phosphoric acid.
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Affiliation(s)
- Kai Su
- Key Laboratory of Green Chemical and Clean Energy Technology, Engineering Research Center of Efficient Utilization for Industrial Waste, School of Chemistry and Chemical Engineering, Guizhou University, Guiyang, 550025, PR China
| | - Guotao Hu
- Guizhou Wengfu (Group) Co., Ltd., Guiyang, 550025, PR China
| | - Tianxiang Zhao
- Key Laboratory of Green Chemical and Clean Energy Technology, Engineering Research Center of Efficient Utilization for Industrial Waste, School of Chemistry and Chemical Engineering, Guizhou University, Guiyang, 550025, PR China.
| | - Huinan Dong
- Key Laboratory of Green Chemical and Clean Energy Technology, Engineering Research Center of Efficient Utilization for Industrial Waste, School of Chemistry and Chemical Engineering, Guizhou University, Guiyang, 550025, PR China
| | - Yi Yang
- Guizhou Wengfu (Group) Co., Ltd., Guiyang, 550025, PR China
| | - Hongyan Pan
- Key Laboratory of Green Chemical and Clean Energy Technology, Engineering Research Center of Efficient Utilization for Industrial Waste, School of Chemistry and Chemical Engineering, Guizhou University, Guiyang, 550025, PR China.
| | - Qian Lin
- Key Laboratory of Green Chemical and Clean Energy Technology, Engineering Research Center of Efficient Utilization for Industrial Waste, School of Chemistry and Chemical Engineering, Guizhou University, Guiyang, 550025, PR China.
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Tian C, Yu H, Zhai R, Zhang J, Gao C, Qi K, Zhang Y, Ma Q, Guo M. Visible Light Photoactivity of g-C 3N 4/MoS 2 Nanocomposites for Water Remediation of Hexavalent Chromium. Molecules 2024; 29:637. [PMID: 38338381 PMCID: PMC10856395 DOI: 10.3390/molecules29030637] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/31/2023] [Revised: 01/21/2024] [Accepted: 01/26/2024] [Indexed: 02/12/2024] Open
Abstract
Water pollution has becoming an increasingly serious issue, and it has attracted a significant amount of attention from scholars. Here, in order remove heavy metal hexavalent chromium (Cr (VI)) from wastewater, graphitic carbon nitride (g-C3N4) was modified with molybdenum disulfide (MoS2) at different mass ratios via an ultrasonic method to synthesize g-C3N4/MoS2 (CNM) nanocomposites as photocatalysts. The nanocomposites displayed efficient photocatalytic removal of toxic hexavalent chromium (Cr (VI)) from water under UV, solar, and visible light irradiation. The CNM composite with a 1:2 g-C3N4 to MoS2 ratio achieved optimal 91% Cr (VI) removal efficiency at an initial 20 mg/L Cr (VI) concentration and pH 3 after 120 min visible light irradiation. The results showed a high pH range and good recycling stability. The g-C3N4/MoS2 nanocomposites exhibited higher performance compared to pure g-C3N4 due to the narrowed band gap of the Z-scheme heterojunction structure and effective separation of photo-generated electron-hole pairs, as evidenced by structural and optical characterization. Overall, the ultrasonic synthesis of g-C3N4/MoS2 photocatalysts shows promise as an efficient technique for enhancing heavy metal wastewater remediation under solar and visible light.
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Affiliation(s)
- Chunmei Tian
- College of Agriculture and Biological Science, Dali University, Dali 671000, China; (C.T.); (H.Y.); (R.Z.); (J.Z.); (C.G.)
| | - Huijuan Yu
- College of Agriculture and Biological Science, Dali University, Dali 671000, China; (C.T.); (H.Y.); (R.Z.); (J.Z.); (C.G.)
| | - Ruiqi Zhai
- College of Agriculture and Biological Science, Dali University, Dali 671000, China; (C.T.); (H.Y.); (R.Z.); (J.Z.); (C.G.)
| | - Jing Zhang
- College of Agriculture and Biological Science, Dali University, Dali 671000, China; (C.T.); (H.Y.); (R.Z.); (J.Z.); (C.G.)
| | - Cuiping Gao
- College of Agriculture and Biological Science, Dali University, Dali 671000, China; (C.T.); (H.Y.); (R.Z.); (J.Z.); (C.G.)
| | - Kezhen Qi
- College of Pharmacy, Dali University, Dali 671000, China;
| | - Yingjie Zhang
- College of Agriculture and Biological Science, Dali University, Dali 671000, China; (C.T.); (H.Y.); (R.Z.); (J.Z.); (C.G.)
- Key Laboratory of Ecological Microbial Remediation Technology of Yunnan Higher Education Institutes, Dali University, Dali 671000, China
| | - Qiang Ma
- School of Architecture and Civil Engineering, Chengdu University, Chengdu 610106, China
| | - Mengxue Guo
- Resources and Environment Institute, Yunnan Land and Resources Vocational College, Kunming 652501, China;
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Witt K, Kaczorowska MA, Bożejewicz D. Efficient, fast, simple, and eco-friendly methods for separation of toxic chromium(VI) ions based on ion exchangers and polymer materials impregnated with Cyphos IL 101, Cyphos IL 104, or D2EHPA. Environ Sci Pollut Res Int 2024; 31:7977-7993. [PMID: 38177645 PMCID: PMC10821846 DOI: 10.1007/s11356-023-31648-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/13/2023] [Accepted: 12/17/2023] [Indexed: 01/06/2024]
Abstract
In this study, we present the results of the first comparison of the elimination of toxic Cr(VI) ions, which are hazardous contamination of the environment, from aqueous solutions using ion exchangers (IEs) and polymer materials (PMs) impregnated with D2EHPA or ionic liquids (Cyphos IL 101 and Cyphos IL 104). Sorption of Cr(VI) ions and desorption from the formulated sorption materials were carried out. In comparison, classical solvent extraction was accomplished. Fourier transform infrared-attenuated total reflectance spectroscopy (FTIR-ATR), scanning electron microscopy-energy dispersive spectroscopy (SEM-EDS), and atomic force microscopy (AFM) have been used for characterization of the structure of developed IEs and PMs. The highest efficiency of adsorption of Cr(VI) ions was obtained using PMs with ionic liquids (>82%). Desorption from these materials were also very efficient (>75%). On the contrary, the application of IEs allowed for obtaining the best results of both, sorption and desorption processes when using D2EHPA (75% and 72%, respectively). The application of PMs and IEs is part of the green chemistry, and the conducted elimination of chromium(VI) ions using developed materials allows for the conclusion that they can potentially be used on a larger scale, e.g., for the treatment of industrial wastewater rich in Cr(VI) ions.
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Affiliation(s)
- Katarzyna Witt
- Faculty of Chemical Technology and Engineering, Bydgoszcz University of Science and Technology, 3 Seminaryjna Street, 85326, Bydgoszcz, PL, Poland.
| | - Małgorzata A Kaczorowska
- Faculty of Chemical Technology and Engineering, Bydgoszcz University of Science and Technology, 3 Seminaryjna Street, 85326, Bydgoszcz, PL, Poland
| | - Daria Bożejewicz
- Faculty of Chemical Technology and Engineering, Bydgoszcz University of Science and Technology, 3 Seminaryjna Street, 85326, Bydgoszcz, PL, Poland
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Wang J, Cheng X, Li P, Fan Q, Wu D, Liang H. Activation of peroxymonosulfate with biochar-supported CuO (CuO@BC) for natural organic matter removal and membrane fouling control. Chemosphere 2023; 341:140044. [PMID: 37660795 DOI: 10.1016/j.chemosphere.2023.140044] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/07/2023] [Revised: 08/30/2023] [Accepted: 08/31/2023] [Indexed: 09/05/2023]
Abstract
To achieve excellent activation efficiency of peroxymonosulfate (PMS), this work prepared a biochar-supported CuO (CuO@BC) catalyst, and the CuO@BC/PMS system was proposed to remove the organic matter in natural surface water and reduce the fouling of ultrafiltration membrane. The successful synthesis of CuO@BC was demonstrated through characterization of its microscopic morphology and chemical composition by various techniques. The prepared heterogeneous catalyst showed a strong catalytic effect on PMS, which significantly removed natural organic matter through the production of active substances (•OH, SO4•-, O2•- and 1O2) from water. With respective degradation rates of 39.4% and 59.4%, the concentrations of DOC and UV254 dropped to 1.702 mg/L and 0.026 cm-1, respectively. Additionally, the CuO@BC/PMS oxidation displayed potent oxidation capabilities for contaminants and fluorescent organics with various molecular weights. The system effectively decreased the amount of organic matter that caused reversible and irreversible fouling of polyethersulfone membranes in natural water by 85.8% and 56.3%, respectively. The main fouling mechanisms changed as well, with standard and complete blocking dominating the entire filtration process. The results demonstrated the capacity of the CuO@BC/PMS system to remove contaminants in natural water and mitigate membrane fouling.
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Affiliation(s)
- Jingxuan Wang
- School of Municipal and Environmental Engineering, Shandong Jianzhu University, Jinan, 250101, PR China
| | - Xiaoxiang Cheng
- School of Municipal and Environmental Engineering, Shandong Jianzhu University, Jinan, 250101, PR China; Resources and Environment Innovation Institute, Shandong Jianzhu University, Jinan, 250101, PR China.
| | - Peijie Li
- State Key Laboratory of Urban Water Resource and Environment, School of Environment, Harbin Institute of Technology, Harbin, 150090, PR China.
| | - Qingshui Fan
- School of Municipal and Environmental Engineering, Shandong Jianzhu University, Jinan, 250101, PR China
| | - Daoji Wu
- School of Municipal and Environmental Engineering, Shandong Jianzhu University, Jinan, 250101, PR China; Resources and Environment Innovation Institute, Shandong Jianzhu University, Jinan, 250101, PR China
| | - Heng Liang
- State Key Laboratory of Urban Water Resource and Environment, School of Environment, Harbin Institute of Technology, Harbin, 150090, PR China
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Ding C, Cai Z, Hu C, Lei J, Wang L, Li Q, Li X, Deng J. Degradation of antiviral drug acyclovir by thermal activated persulfate process: Kinetics study and modeling. Chemosphere 2023; 323:138247. [PMID: 36842560 DOI: 10.1016/j.chemosphere.2023.138247] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/23/2022] [Revised: 01/31/2023] [Accepted: 02/23/2023] [Indexed: 06/18/2023]
Abstract
Pharmaceutical and personal care products (PPCPs) pose a great threat to water environment security. In this study, acyclovir (ACV) was efficiently degraded by thermally activated persulfate (TAP) system. The ACV degradation increased with rising reaction temperature and persulfate dosage. With the existence of inorganic anions and humic acid, ACV removal was retarded to varying degrees. Under strong alkaline condition, it was observed that the degradation of ACV was significantly inhibited. In addition, Kintecus software was employed to simulate ACV removal and achieved a good fit with the experimental results. The contribution rates of main reactive radicals under acidic, neutral, and alkaline conditions were investigated, and the contribution of hydroxyl radical (⋅OH) increased significantly under alkaline condition. The main active species were identified as sulfate radical (SO4⋅-) and ⋅OH through quenching experiment, and the second-order reaction rate constants of SO4⋅- and ∙OH reacted with ACV were calculated to be 9.17 × 109 M-1 s-1 and 2.74 × 109 M-1 s-1, respectively. The main degradation pathways included addition of free radicals, oxidation of branch chain and ring opening. The acute and chronic toxicity of intermediates to organisms predicted by ECOSAR were significantly reduced compared with that of ACV.
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Affiliation(s)
- Chunsheng Ding
- College of Civil Engineering, Zhejiang University of Technology, Hangzhou 310023, China
| | - Zhiyue Cai
- College of Civil Engineering, Zhejiang University of Technology, Hangzhou 310023, China
| | - Chenkai Hu
- College of Civil Engineering, Zhejiang University of Technology, Hangzhou 310023, China
| | - Jia Lei
- College of Civil Engineering, Zhejiang University of Technology, Hangzhou 310023, China
| | - Lei Wang
- College of Civil Engineering, Zhejiang University of Technology, Hangzhou 310023, China
| | - Qingsong Li
- Water Resources and Environmental Institute, Xiamen University of Technology, Xiamen 361005, China
| | - Xueyan Li
- School of Environmental Science and Engineering, Suzhou University of Science and Technology, Suzhou 215009, China
| | - Jing Deng
- College of Civil Engineering, Zhejiang University of Technology, Hangzhou 310023, China.
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Kong Y, Huang Z, Chu H, Ma Y, Ma J, Nie Y, Ding L, Chen Z, Shen J. Enhanced removal of aqueous Cr(VI) by the in situ iron loaded activated carbon through a facile impregnation with Fe(II) and Fe(VI) two step method: Mechanism study. Environ Sci Pollut Res Int 2023; 30:38480-38499. [PMID: 36577825 DOI: 10.1007/s11356-022-24876-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/11/2022] [Accepted: 12/15/2022] [Indexed: 06/17/2023]
Abstract
In this study, a novel in situ iron-loaded activated carbon (AFPAC) was prepared by a FeSO4/K2FeO4 impregnation and oxidation combination two-step supported on activated carbon for enhanced removal of Cr(VI) from aqueous solutions. Cr(VI) removal efficiency greatly increased by AFPAC more than 70% than that of fresh activated carbon (AC), which is due to rich iron oxides formed in situ and the synergistic effect between iron oxides and activated carbon. Cr(VI) adsorption behaviors on AFPAC under different water quality parameters were investigated. The maximum monolayer adsorption capacities for Cr(VI) by AFPAC are as high as 26.24 mg/g, 28.65 mg/g, and 32.05 mg/g at 25 °C, 35 °C and 45 °C at pH 4, respectively. Density functional theory (DFT) results showed that the adsorption energy of K2Cr2O7 on the surface of FeOOH was - 2.52 eV, which was greater than that on the surface of bare AC, and more charge transfer occurred during the adsorption of K2Cr2O7 on the surface of FeOOH, greatly promoting the formation of Cr = O-Fe. Cr(VI) removal by AFPAC included electrostatic attraction, redox reaction, coordinate complexation, and co-precipitation. Cr(VI) adsorption process on AFPAC consisted of the three reaction steps: (1) AFPAC was fast protonation and Cr2O72- would electrostatically attract to the positively charged AFPAC surface. (2) Cr2O72- was reduced into Cr2O3 by the carbons bond to the oxygen functionalities on activated carbon and the redox reaction process of FeSO4 and K2FeO4. (3) The inner-sphere complexes were formed, and adsorbed on AFPAC by iron oxides and then co-precipitation.
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Affiliation(s)
- Yanli Kong
- School of Civil Engineering and Architecture, Anhui University of Technology, Maanshan, 243002, Anhui, China
- Engineering Research Center of Biomembrane Water Purification and Utilization Technology, Ministry of Education, Maanshan, 243002, Anhui, China
| | - Zhiyan Huang
- School of Civil Engineering and Architecture, Anhui University of Technology, Maanshan, 243002, Anhui, China
- Engineering Research Center of Biomembrane Water Purification and Utilization Technology, Ministry of Education, Maanshan, 243002, Anhui, China
| | - Hangyu Chu
- School of Civil Engineering and Architecture, Anhui University of Technology, Maanshan, 243002, Anhui, China
- Engineering Research Center of Biomembrane Water Purification and Utilization Technology, Ministry of Education, Maanshan, 243002, Anhui, China
| | - Yaqian Ma
- School of Civil Engineering and Architecture, Anhui University of Technology, Maanshan, 243002, Anhui, China
| | - Jiangya Ma
- School of Civil Engineering and Architecture, Anhui University of Technology, Maanshan, 243002, Anhui, China.
- Engineering Research Center of Biomembrane Water Purification and Utilization Technology, Ministry of Education, Maanshan, 243002, Anhui, China.
| | - Yong Nie
- School of Civil Engineering and Architecture, Anhui University of Technology, Maanshan, 243002, Anhui, China
- Engineering Research Center of Biomembrane Water Purification and Utilization Technology, Ministry of Education, Maanshan, 243002, Anhui, China
| | - Lei Ding
- School of Civil Engineering and Architecture, Anhui University of Technology, Maanshan, 243002, Anhui, China
- Engineering Research Center of Biomembrane Water Purification and Utilization Technology, Ministry of Education, Maanshan, 243002, Anhui, China
| | - Zhonglin Chen
- State Key Laboratory of Urban Water Resources and Environment, School of Municipal & Environmental Engineering, Harbin Institute of Technology, Harbin, 150090, China
| | - Jimin Shen
- State Key Laboratory of Urban Water Resources and Environment, School of Municipal & Environmental Engineering, Harbin Institute of Technology, Harbin, 150090, China
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Abstract
To provide guidance for the selection of woody-activated carbon in the treatment of wastewater containing hexavalent chromium (Cr(VI)), the adsorption tests on two varieties of commercial woody-activated carbon powder from different manufacturers were carried out. The physicochemical properties and structural characteristics of activated carbon were studied by using elemental, chemical, and instrumental analyses. The adsorption mechanism of Cr(VI) was discussed by investigating the factors affecting the removal of hexavalent chromium. The two kinds of woody-activated carbon have microporous and mesoporous structures. Commercial woody-activated carbon No.1 (ACI) has a more extensive specific surface area and a better-developed pore structure. While ACI exhibits a higher adsorption capability when the content of Cr(VI) is high, commercial woody-activated carbon No.2 (AC) can remove hexavalent chromium fast when the concentration is low. A rise in pH value is not helpful for the materials to remove Cr(VI) from solutions. For Cr(VI) removal, the optimum pH value is 2. The adsorption of Cr(VI) by AC and ACI followed the pseudo-second-order kinetic model and Langmuir isothermal adsorption equation. The maximum adsorption value of Cr(VI) is 154.56 mg/g for AC and 241.55 mg/g for ACI. There is chemical adsorption during the Cr(VI) removal. A lot of Cr (Ⅲ) was formed by Cr(VI). The abundance of pores and the reducing ability of the materials are essential for the removal of Cr(VI).
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Affiliation(s)
- Hua Wang
- College of Chemistry and Chemical Engineering, Yulin City, 719000, China,Shaanxi Provincial Key Laboratory of Clean Utilization of Low-Modified Coal, Yulin City, 719000, China,Corresponding author. College of Chemistry and Chemical Engineering, Yulin University, Chongwen Road No.51, Yulin City, 719000, Shaanxi Province, China.
| | - Wencheng Wang
- College of Chemistry and Chemical Engineering, Yulin City, 719000, China
| | - Song Zhou
- College of Chemistry and Chemical Engineering, Yulin City, 719000, China
| | - Xuchun Gao
- College of Chemistry and Chemical Engineering, Yulin City, 719000, China,Shaanxi Provincial Key Laboratory of Clean Utilization of Low-Modified Coal, Yulin City, 719000, China
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11
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Liu B, Xin YN, Zou J, Khoso FM, Liu YP, Jiang XY, Peng S, Yu JG. Removal of Chromium Species by Adsorption: Fundamental Principles, Newly Developed Adsorbents and Future Perspectives. Molecules 2023; 28:molecules28020639. [PMID: 36677697 PMCID: PMC9861687 DOI: 10.3390/molecules28020639] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 12/08/2022] [Revised: 12/24/2022] [Accepted: 01/05/2023] [Indexed: 01/11/2023]
Abstract
Emerging chromium (Cr) species have attracted increasing concern. A majority of Cr species, especially hexavalent chromium (Cr(VI)), could lead to lethal effects on human beings, animals, and aquatic lives even at low concentrations. One of the conventional water-treatment methodologies, adsorption, could remove these toxic Cr species efficiently. Additionally, adsorption possesses many advantages, such as being cost-saving, easy to implement, highly efficient and facile to design. Previous research has shown that the application of different adsorbents, such as carbon nanotubes (carbon nanotubes (CNTs) and graphene oxide (GO) and its derivatives), activated carbons (ACs), biochars (BCs), metal-based composites, polymers and others, is being used for Cr species removal from contaminated water and wastewater. The research progress and application of adsorption for Cr removal in recent years are reviewed, the mechanisms of adsorption are also discussed and the development trend of Cr treatment by adsorption is proposed.
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Affiliation(s)
- Bo Liu
- State Key Laboratory of Vanadium and Titanium Resources Comprehensive Utilization, Panzhihua 617000, China
| | - Ya-Nan Xin
- State Key Laboratory of Vanadium and Titanium Resources Comprehensive Utilization, Panzhihua 617000, China
| | - Jiao Zou
- College of Chemistry and Chemical Engineering, Central South University, Changsha 410083, China
- School of Chemistry and Materials Engineering, Huizhou University, Huizhou 516007, China
| | - Fazal Muhammad Khoso
- College of Chemistry and Chemical Engineering, Central South University, Changsha 410083, China
| | - Yi-Ping Liu
- College of Chemistry and Chemical Engineering, Central South University, Changsha 410083, China
| | - Xin-Yu Jiang
- College of Chemistry and Chemical Engineering, Central South University, Changsha 410083, China
| | - Sui Peng
- State Key Laboratory of Vanadium and Titanium Resources Comprehensive Utilization, Panzhihua 617000, China
- Correspondence: (S.P.); (J.-G.Y.); Tel./Fax: +86-731-88879616 (J.-G.Y.)
| | - Jin-Gang Yu
- College of Chemistry and Chemical Engineering, Central South University, Changsha 410083, China
- Correspondence: (S.P.); (J.-G.Y.); Tel./Fax: +86-731-88879616 (J.-G.Y.)
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12
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Li Y, Lan L, Zhou F, Peng J, Guo L, Wang F, Zhang Z, Wang L, Mao J. Flexible and easy-handling pristine polypyrrole membranes with bayberry-like vesicle structure for enhanced Cr(VI) removal from aqueous solution. J Hazard Mater 2022; 439:129598. [PMID: 35872453 DOI: 10.1016/j.jhazmat.2022.129598] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/30/2022] [Revised: 07/08/2022] [Accepted: 07/12/2022] [Indexed: 06/15/2023]
Abstract
Polypyrrole has been extensively explored for Cr(VI) removal from wastewater towing to the advantages of superior performance, low cost, facile synthesis, and high environmental stability. However, the unsatisfactory adsorption capacity and complicated process of adsorbent separation from aqueous solutions remain a huge challenge, limiting its practical application. Herein, a flexible PPy membrane with bayberry-like vesicle structures (PPy-B) was prepared via template-assisted interfacial polymerization. It was found that sodium sulfosalicylate not only improved the flexibility and strength of the PPy-B membrane for easy-handling but also participated in the polymerization of PPy as a dopant to improve the specific surface area and doping level for increasing adsorption sites. Benefiting from these, the easy-handling PPy-B membrane exhibited a high adsorption capacity (586.90-682.50 mg/g at 298-318 K), a high reusability (five adsorption-desorption cycles), and a high ultimate adsorption capacity after adsorption-desorption cycles until membrane failure (1174.86 mg/g at 298 K). The proposed mechanisms of the enhanced Cr(VI) removal involve electrostatic adsorption, reduction, and ion exchange. This flexible PPy membrane therefore shows attractive advantages in wastewater treatment.
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Affiliation(s)
- Yimeng Li
- Key Laboratory of Textile Science & Technology, Ministry of Education, College of Textiles, Donghua University, Shanghai 201620, China; Key Laboratory of Textile Industry for Biomedical Textile Materials and Technology, Donghua University, Shanghai 201620, China
| | - Lizhen Lan
- Key Laboratory of Textile Science & Technology, Ministry of Education, College of Textiles, Donghua University, Shanghai 201620, China; Key Laboratory of Textile Industry for Biomedical Textile Materials and Technology, Donghua University, Shanghai 201620, China
| | - Fengkai Zhou
- Key Laboratory of Textile Science & Technology, Ministry of Education, College of Textiles, Donghua University, Shanghai 201620, China; Key Laboratory of Textile Industry for Biomedical Textile Materials and Technology, Donghua University, Shanghai 201620, China
| | - Jiamin Peng
- Key Laboratory of Textile Science & Technology, Ministry of Education, College of Textiles, Donghua University, Shanghai 201620, China; Key Laboratory of Textile Industry for Biomedical Textile Materials and Technology, Donghua University, Shanghai 201620, China
| | - Lamei Guo
- Key Laboratory of Textile Science & Technology, Ministry of Education, College of Textiles, Donghua University, Shanghai 201620, China
| | - Fujun Wang
- Key Laboratory of Textile Science & Technology, Ministry of Education, College of Textiles, Donghua University, Shanghai 201620, China; Key Laboratory of Textile Industry for Biomedical Textile Materials and Technology, Donghua University, Shanghai 201620, China
| | - Ze Zhang
- Axe médecine régénératrice, Centre de recherche du CHU de Québec - Université Laval, Québec, QC G1V 0A6, Canada; Département de chirurgie, Faculté de médecine, Université Laval, Centre de recherche du CHU de Québec - Université Laval, Québec, QC G1V 0A6, Canada
| | - Lu Wang
- Key Laboratory of Textile Science & Technology, Ministry of Education, College of Textiles, Donghua University, Shanghai 201620, China; Key Laboratory of Textile Industry for Biomedical Textile Materials and Technology, Donghua University, Shanghai 201620, China
| | - Jifu Mao
- Key Laboratory of Textile Science & Technology, Ministry of Education, College of Textiles, Donghua University, Shanghai 201620, China; Key Laboratory of Textile Industry for Biomedical Textile Materials and Technology, Donghua University, Shanghai 201620, China.
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Liu Y, Shan H, Pang Y, Zhan H, Zeng C. Iron modified chitosan/coconut shell activated carbon composite beads for Cr(VI) removal from aqueous solution. Int J Biol Macromol 2022; 224:156-169. [DOI: 10.1016/j.ijbiomac.2022.10.112] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2022] [Revised: 10/03/2022] [Accepted: 10/12/2022] [Indexed: 11/05/2022]
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14
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Wang D, Gong C, Zhao H. Au NPs@NC@MnO2 with exceptional nano-enzyme activity for sensitive colorimetric detection of Cr (VI). Microchem J 2022. [DOI: 10.1016/j.microc.2022.107706] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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15
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Li Y, Li H, Jiang S, Zhou Y, Cao D, Che X, Yang Y, Shang J, Cheng X. Enhanced adsorption for fluoroquinolones by MnOx-modified palygorskite composites: Preparation, properties and mechanism. Sep Purif Technol 2022; 299:121468. [DOI: 10.1016/j.seppur.2022.121468] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
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Khurshid H, Mustafa MRU, Isa MH. Adsorption of chromium, copper, lead and mercury ions from aqueous solution using bio and nano adsorbents: A review of recent trends in the application of AC, BC, nZVI and MXene. Environ Res 2022; 212:113138. [PMID: 35364043 DOI: 10.1016/j.envres.2022.113138] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/16/2021] [Revised: 02/18/2022] [Accepted: 03/15/2022] [Indexed: 06/14/2023]
Abstract
Recent trends in adsorption of Chromium (Cr), Copper (Cu), Lead (Pb) and Mercury (Hg) in wastewater using (i) carbonaceous materials including activated carbon (AC) and biochar (BC), and (ii) nanomaterials including nano zero-valent iron (nZVI) and MXenes have been discussed in this paper. It has been found that adsorption capacity depends largely on the adsorbent modification technique, initial pH of wastewater, dosage of adsorbent, contact time and initial concentration of the pollutants. The pH value ranges for maximum removal of Cr, Cu, Pb and Hg have been reported as 2-4, 5-6, 5-8 and 3-8, respectively. Up to 99% removal of metals has been reported using AC, BC, nZVI and MXene. The mechanism involves the reduction and chemical adsorption of metals. AC and BC have a higher surface area (up to 5000 m2/g) compared to nZVI (up to 500 m2/g) and MXene (up to 67.66 m2/g). However, the higher reactivity and regeneration capacity of nZVI and MXene make them suitable adsorbents. From a practical point of view the application of adsorbents for real effluents, cost analysis, regeneration capability and reuse of heavy metals are some aspects that need attention in future studies. The removal efficiencies of AC and BC are comparable to the nZVI and MXene. The cost analysis may be an attractive aspect to decide the future application of these adsorbents at large scale.
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Affiliation(s)
- Hifsa Khurshid
- Department of Civil & Environmental Engineering, Universiti Teknologi PETRONAS, 32610, Seri Iskandar, Perak Darul Ridzuan, Malaysia.
| | - Muhammad Raza Ul Mustafa
- Department of Civil & Environmental Engineering, Universiti Teknologi PETRONAS, 32610, Seri Iskandar, Perak Darul Ridzuan, Malaysia; Centre for Urban Resource Sustainability, Institute of Self-Sustainable Building, Universiti Teknologi PETRONAS, Seri Iskandar, 32610, Perak, Malaysia
| | - Mohamed Hasnain Isa
- Civil Engineering Programme, Faculty of Engineering, Universiti Teknologi Brunei, Tungku Highway, Gadong, BE1410, Brunei Darussalam
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Sinha R, Kumar R, Sharma P, Kant N, Shang J, Aminabhavi TM. Removal of hexavalent chromium via biochar-based adsorbents: State-of-the-art, challenges, and future perspectives. J Environ Manage 2022; 317:115356. [PMID: 35623129 DOI: 10.1016/j.jenvman.2022.115356] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/21/2022] [Revised: 05/01/2022] [Accepted: 05/17/2022] [Indexed: 06/15/2023]
Abstract
Chromium originates from geogenic and extensive anthropogenic activities and significantly impacts natural ecosystems and human health. Various methods have been applied to remove hexavalent chromium (Cr(VI)) from aquatic environmental matrices, including adsorption via different adsorbents, which is considered to be the most common and low-cost approach. Biochar materials have been recognized as renewable carbon sorbents, pyrolyzed from various biomass at different temperatures under limited/no oxygen conditions for heavy metals remediation. This review summarizes the sources, chemical speciation & toxicity of Cr(VI) ions, and raw and modified biochar applications for Cr(VI) remediation from various contaminated matrices. Mechanistic understanding of Cr(VI) adsorption using different biochar-based materials through batch and saturated column adsorption experiments is documented. Electrostatic interaction and ion exchange dominate the Cr(VI) adsorption onto the biochar materials in acidic pH media. Cr(VI) ions tend to break down as HCrO4-, CrO42-, and Cr2O72- ions in aqueous solutions. At low pH (∼1-4), the availability of HCrO4- ions attributes the electrostatic forces of attraction due to the available functional groups such as -NH4+, -COOH, and -OH2+, which encourages higher adsorption of Cr(VI). Equilibrium isotherm, kinetic, and thermodynamic models help to understand Cr(VI)-biochar interactions and their adsorption mechanism. The adsorption studies of Cr(VI) are summarized through the fixed-bed saturated column experiments and Cr-contaminated real groundwater analysis using biochar-based sorbents for practical applicability. This review highlights the significant challenges in biochar-based material applications as green, renewable, and cost-effective adsorbents for the remediation of Cr(VI). Further recommendations and future scope for the implications of advanced novel biochar materials for Cr(VI) removal and other heavy metals are elegantly discussed.
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Affiliation(s)
- Rama Sinha
- School of Ecology and Environment Studies, Nalanda University, Rajgir, Bihar, 803 116, India
| | - Rakesh Kumar
- School of Ecology and Environment Studies, Nalanda University, Rajgir, Bihar, 803 116, India
| | - Prabhakar Sharma
- School of Ecology and Environment Studies, Nalanda University, Rajgir, Bihar, 803 116, India.
| | - Nishi Kant
- Department of Environmental Science and Engineering, Indian Institute of Technology (Indian School of Mines), Dhanbad, 826 004, Jharkhand, India
| | - Jianying Shang
- Department of Soil and Water Science, China Agricultural University, Beijing, 100083, China
| | - Tejraj M Aminabhavi
- School of Advanced Sciences, KLE Technological University, Hubballi, 580 031, India; School of Engineering, University of Petroleum and Energy Studies, Bidholi, Dehradun, Uttarakhand, 248 007, India; Department of Chemistry, Karnatak University, Dharwad, 580 003, India.
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18
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Yuan D, Zhai Z, Zhu E, Liu H, Jiao T, Tang S. Humic Acid Removal in Water via UV Activated Sodium Perborate Process. Coatings 2022; 12:885. [DOI: 10.3390/coatings12070885] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Abstract
Humic acid (HA) has complex molecular structure and is capable of adsorption, ion exchange, and chelation with organic and inorganic pollutants in water bodies, worsening water quality and jeopardizing human health and ecological environment. How to effectively remove HA from water is one of the research focuses of this paper. In this study, the UV-activated sodium perborate (SPB) synergistic system (UV/SPB) was established to eliminate HA in water. The effects of initial HA concentration, SPB dose, and initial pH value on the HA elimination were determined, and the main mechanisms of the synergy and HA degradation were explored. The outcomes show that the HA elimination ratio by the sole UV and only SPB system were only 0.5% and 1.5%, respectively. The HA removal of UV/SPB reached 88.8%, which can remove HA more effectively than other systems. Free radical masking experiment proved that hydroxyl radical produced by SPB activation is the main active substance for HA removal. The results of UV-vis absorption spectrum, absorbance ratio, specific UV absorbance, and excitation–emission matrix spectroscopy verified that the UV/SPB system can effectively decompose and mineralize HA.
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Retnam B, Balamirtham H, Aravamudan K. Maximizing Adsorption Involving Three Solutes on Enhanced Adsorbents Using the Mixture-Process Variable Design. ACS Omega 2022; 7:19561-19578. [PMID: 35721906 PMCID: PMC9202268 DOI: 10.1021/acsomega.2c01284] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/03/2022] [Accepted: 05/19/2022] [Indexed: 06/15/2023]
Abstract
Unmodified (UN), acid-treated (AT) and microwave-acid-treated (MAT) activated carbons were optimized for their solute removal efficacies by adjusting feed mixture compositions and process conditions. Acetaminophen, benzotriazole, and caffeine were used either individually or as binary/ternary mixtures in this study. The process conditions considered were the pH, adsorbent dosage, and type of adsorbent. Experimental responses such as total adsorbent loading (q total) and total percentage removal (PRtotal) were fitted with empirical models that had high adjusted R 2 (>0.95), insignificant lack of fit (p-value > 0.22), and high model predictive R 2 (>0.93). Mixture compositions of the feed were found to interact significantly not only among themselves but with process variables as well. Hence, adsorption optimization must simultaneously consider mixture as well as process variables. The conventional response surface methodology for mixtures, termed as ridge analysis, optimizes mixture compositions at specified values of process variables. An improved steepest ascent method which considers mixture and process variables simultaneously was developed in this work. This could track the path of steepest ascent toward globally optimal settings, from any arbitrary starting point within the design space. For the chosen adsorbent, optimal settings for feed mixture compositions and pH were found to change along this steepest ascent path. The feed compositions, pH, and adsorbent dosage identified for maximum adsorbent utilization were usually quite different from those identified for maximum total percentage removal. When both these objectives were optimized together, the most favorable compromise solutions for q total and PRtotal were, respectively, 264.1 mg/g and 43.4% for UN, 294.9 mg/g and 52.5% for AT, and 336.6 mg/g and 55.9% for MAT.
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Affiliation(s)
- Bharathi
Ganesan Retnam
- Department
of Chemical Engineering, Indian Institute
of Technology Madras, Chennai 600036, India
- Department
of Chemical Engineering, KPR Institute of
Engineering and Technology, Coimbatore 641 407, India
| | - Hariharan Balamirtham
- Department
of Chemical Engineering, Indian Institute
of Technology Madras, Chennai 600036, India
| | - Kannan Aravamudan
- Department
of Chemical Engineering, Indian Institute
of Technology Madras, Chennai 600036, India
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