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Tan J, Kong L, Huang Q, Gan Y, Lu S. Harnessing the power of polyethyleneimine in modifying chitosan surfaces for efficient anion dyes and hexavalent chromium removal. Environ Res 2024; 247:118192. [PMID: 38224939 DOI: 10.1016/j.envres.2024.118192] [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: 11/18/2023] [Revised: 01/09/2024] [Accepted: 01/10/2024] [Indexed: 01/17/2024]
Abstract
In this investigation, synthesis of a surface-functionalized chitosan known as amino-rich chitosan (ARCH) was achieved by successful modification of chitosan by polyethyleneimine (PEI). The synthesized ARCH was characterized by a specific surface area of 8.35 m2 g-1 and a microporous structure, with pore sizes predominantly under 25 nm. The Zeta potential of ARCH maintained a strong positive charge across a wide pH range of 3-11. These characteristics contribute to its high adsorption efficiency in aqueous solutions, demonstrated by its application in removing various anionic dyes, including erioglaucine disodium salt (EDS), methyl orange (MO), amaranth (ART), tartrazine (TTZ), and hexavalent chromium ions (Cr(VI)). The adsorption capacities (Qe) for these contaminants were measured at 1301.15 mg g-1 for EDS, 1025.45 mg g-1 for MO, 940.72 mg g-1 for ART, 732.96 mg g-1 for TTZ, and 350.15 mg g-1 for Cr(VI). A significant observation was the rapid attainment of adsorption equilibrium, occurring within 10 min for ARCH. The adsorption behavior was well-described by the Pseudo-second-order and Langmuir models. Thermodynamic studies indicated that the adsorption process is spontaneous and endothermic in nature. Additionally, an increase in temperature was found to enhance the adsorption capacity of ARCH. The material demonstrated robust stability and selective adsorption capabilities in varied conditions, including different organic compounds, pH environments, sodium salt presence, and in the face of interfering ions. After five cycles of adsorption, ARCH maintained about 60% of its initial adsorption capacity. Due to its efficient adsorption performance, simple synthesis process, low biological toxicity, and cost-effectiveness, ARCH is a promising candidate for future water treatment technologies.
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Affiliation(s)
- Jisuan Tan
- Key Laboratory of New Processing Technology for Nonferrous Metal & Materials, Ministry of Education, Guangxi Key Laboratory of Optical and Electronic Materials and Devices, Guilin University of Technology, Guilin 541004, China; Guangxi Key Laboratory of Green Chemical Materials and Safety Technology, Beibu Gulf University, Qinzhou 515000, China.
| | - Lingzhen Kong
- Guangxi Key Laboratory of Green Chemical Materials and Safety Technology, Beibu Gulf University, Qinzhou 515000, China
| | - Qiaoxian Huang
- Guangxi Key Laboratory of Green Chemical Materials and Safety Technology, Beibu Gulf University, Qinzhou 515000, China
| | - Yulin Gan
- Guangxi Key Laboratory of Green Chemical Materials and Safety Technology, Beibu Gulf University, Qinzhou 515000, China
| | - Shaorong Lu
- Key Laboratory of New Processing Technology for Nonferrous Metal & Materials, Ministry of Education, Guangxi Key Laboratory of Optical and Electronic Materials and Devices, Guilin University of Technology, Guilin 541004, China.
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2
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Swathilakshmi AV, Poonkothai M. Ecofriendly Approach on the Removal of Reactive Orange 107 from Aqueous Solutions Using Cladophora Species as a Novel Biosorbent. Mol Biotechnol 2024; 66:500-516. [PMID: 37245201 DOI: 10.1007/s12033-023-00764-5] [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] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2023] [Accepted: 04/29/2023] [Indexed: 05/29/2023]
Abstract
The efficiency of Cladophora species for the removal of Reactive Orange 107 (RO107) from the aqueous solution was evaluated through batch adsorption studies by optimising various process parameters such as pH (3-8), dye concentration (100-500 mg/l), biosorbent concentration (100-500 mg/l), temperature (25-45 °C) and contact time (12-108 h). The results revealed that the optimum conditions for RO107 decolourisation (87%) was found on 72 h of incubation with 100 mg/l dye concentration amended with 200 mg/l biosorbent at pH 6 at 25 °C. The mechanism of dye adsorption was evaluated using isotherms, kinetics and thermodynamic models. The experimental data fitted well with Langmuir isotherm and pseudo-second-order kinetic models. Thermodynamic studies revealed that the adsorption process was endothermic, spontaneous and feasible in nature. Recovery of RO107 from the Cladophora sp. was maximum when 0.1 M HNO3 was used as an eluent. UV-Visible, FT-IR and SEM analyses reveal the interaction between the biosorbent-adsorbate and confirm the process of decolourisation by Cladophora sp. In order to evaluate the nature of the untreated and treated dye solutions, toxicological studies were conducted and the results revealed that the treated dye solution was non- toxic as compared with untreated dye solution. The results of the docking study proved that there was a substantial binding energy between RO107 and the protein (Cytochrome C6) of Cladophora sp. Hence, Cladophora sp. proves to be a promising biosorbent to decolourise RO107 and its potential can be explored in the textile sectors.
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Affiliation(s)
- A V Swathilakshmi
- Department of Zoology, School of Biosciences, Avinashilingam Institute for Home Science and Higher Education for Women, Coimbatore, Tamil Nadu, 641043, India
| | - M Poonkothai
- Department of Zoology, School of Biosciences, Avinashilingam Institute for Home Science and Higher Education for Women, Coimbatore, Tamil Nadu, 641043, India.
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Câmara ABF, Silva MRL, de Longe C, Moura HOMA, Silva SRB, de Souza MAF, Rodríguez-Castellón E, de Carvalho LS. Computational and experimental assessment of efficient dye adsorption method from aqueous effluents by halloysite and palygorskite clay minerals. Environ Sci Pollut Res Int 2023:10.1007/s11356-023-31546-w. [PMID: 38158527 DOI: 10.1007/s11356-023-31546-w] [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] [Subscribe] [Scholar Register] [Received: 09/11/2023] [Accepted: 12/10/2023] [Indexed: 01/03/2024]
Abstract
The removal of dyes from effluents of textile industries represents a technological challenge, due to their significant environmental impact. The application of halloysite (Hal) and palygorskite (Pal) clay minerals as adsorbents for the removal of Congo red (CR) and methylene blue (MB) was evaluated in this work. The materials were applied both in natural and acid-treated forms, and characterized by XRD, XPS, SEM-EDS, FTIR, and N2 adsorption-desorption isotherm techniques to identify their properties and main active sites. The adsorbents showed potential to remove CR (> 98%) and MB (> 85%) within 180 min, using 0.3 g adsorbent and initial dye concentration of 250 mg L-1. Semi-empirical quantum mechanical calculations (SQM) confirmed the interaction mechanism between dyes and the adsorbents via chemisorption (- 69.0 kcal mol-1 < Eads < - 28.8 kcal mol-1), which was further observed experimentally due to the high fit of adsorption data to pseudo-second order kinetic model (R2 > 0.99) and Langmuir isotherm (R2 > 0.98). The use of Pal and Hal to remove dyes was proven to be economically and environmentally viable for industrial application.
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Affiliation(s)
- Anne B F Câmara
- Institute of Chemistry, Federal University of Rio Grande Do Norte, Energetic Technologies Research Group, Natal, 59078-900, Brazil
| | - Mariana R L Silva
- Institute of Chemistry, Federal University of Rio Grande Do Norte, Energetic Technologies Research Group, Natal, 59078-900, Brazil
| | - Clenildo de Longe
- Institute of Chemistry, Federal University of Rio Grande Do Norte, Energetic Technologies Research Group, Natal, 59078-900, Brazil
| | - Heloise O M A Moura
- Institute of Chemistry, Federal University of Rio Grande Do Norte, Energetic Technologies Research Group, Natal, 59078-900, Brazil
| | - Sérgio R B Silva
- Institute of Chemistry, Federal University of Rio Grande Do Norte, Energetic Technologies Research Group, Natal, 59078-900, Brazil
| | - Miguel A F de Souza
- Institute of Chemistry, Federal University of Rio Grande Do Norte, Energetic Technologies Research Group, Natal, 59078-900, Brazil
| | - Enrique Rodríguez-Castellón
- Dpto. de Química Inorgánica, Cristalografía y Mineralogía, Facultad de Ciencias, Universidad de Málaga, 29071, Málaga, Spain
| | - Luciene S de Carvalho
- Institute of Chemistry, Federal University of Rio Grande Do Norte, Energetic Technologies Research Group, Natal, 59078-900, Brazil.
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Esmaeili Bidhendi M, Parandi E, Mahmoudi Meymand M, Sereshti H, Rashidi Nodeh H, Joo SW, Vasseghian Y, Mahmoudi Khatir N, Rezania S. Removal of lead ions from wastewater using magnesium sulfide nanoparticles caged alginate microbeads. Environ Res 2023; 216:114416. [PMID: 36181897 DOI: 10.1016/j.envres.2022.114416] [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: 05/23/2022] [Revised: 07/24/2022] [Accepted: 09/20/2022] [Indexed: 06/16/2023]
Abstract
In this study, an adsorbent made of alginate (Alg) caged magnesium sulfide nanoparticles (MgS) microbeads were used to treat lead ions (Pb2+ ions). The MgS nanoparticles were synthesized at low temperatures, and Alg@MgS hydrogel microbeads were made by the ion exchange process of the composite materials. The newly fabricated Alg@MgS was characterized by XRD, SEM, and FT-IR. The adsorption conditions were optimized for the maximum removal of Pb2+ ions by adjusting several physicochemical parameters, including pH, initial concentration of lead ions, Alg/MgS dosage, reaction temperature, equilibration time, and the presence of co-ions. This is accomplished by removing the maximum amount of Pb2+ ions. Moreover, the adsorbent utilized more than six times with a substantial amount (not less than 60%) of Pb2+ ions was eliminated. Considering the ability of sodium alginate (SA) for excellent metal chelation and controlled nanosized pore structure, the adsorption equilibrium of Alg@MgS can be reached in 60 min, and the highest adsorption capacity for Pb2+ was 84.7 mg/g. The sorption mechanism was explored by employing several isotherms. It was found that the Freundlich model fits the adsorption process quite accurately. The pseudo-second-order model adequately described the adsorption kinetics.
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Affiliation(s)
- Mehdi Esmaeili Bidhendi
- Department of Environmental Engineering, Graduate Faculty of Environment, University of Tehran, Iran
| | - Ehsan Parandi
- Department of Food Science & Technology, Faculty of Agricultural Engineering and Technology, University of Tehran, Karaj, Iran; Food Technology and Agricultural Products Research Center, Standard Research Institute (SRI), Karaj, Iran
| | - Masoumeh Mahmoudi Meymand
- Food Technology and Agricultural Products Research Center, Standard Research Institute (SRI), Karaj, Iran
| | - Hassan Sereshti
- Department of Chemistry, Faculty of Science, University of Tehran, Tehran, Iran.
| | - Hamid Rashidi Nodeh
- Food Technology and Agricultural Products Research Center, Standard Research Institute (SRI), Karaj, Iran
| | - Sang-Woo Joo
- Department of Chemistry, Soongsil University, Seoul, 06978, South Korea
| | - Yasser Vasseghian
- Department of Chemistry, Soongsil University, Seoul, 06978, South Korea; Department of Sustainable Engineering, Saveetha School of Engineering, SIMATS, Chennai, 602105, India
| | - Nadia Mahmoudi Khatir
- Department of Biotechnology, Faculty of Biological Sciences, Alzahra University, Tehran, Iran
| | - Shahabaldin Rezania
- Department of Environment and Energy, Sejong University, Seoul, 05006, South Korea.
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Zaib Q, Ryenchindorj U, Putra AS, Kyung D, Park HS. Optimization of tetracycline removal from water by iron-coated pine-bark biochar. Environ Sci Pollut Res Int 2023; 30:4972-4985. [PMID: 35976587 DOI: 10.1007/s11356-022-22476-0] [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: 05/02/2022] [Accepted: 08/07/2022] [Indexed: 06/15/2023]
Abstract
We synthesized iron-coated pine-bark biochar (Fe-PBB) and determined the optimal conditions for removing the antibiotic tetracycline from water. The Fe-PBB was synthesized by depositing iron oxide on pyrolyzed pine-bark waste via a facile co-precipitation method. Characterization (SEM, EDX, and TGA) showed successful deposition of a mass of approximately 27% (w/w) iron on the PBB to synthesize Fe-PBB. Fe-PBB exhibited five times higher adsorption capacity (~ 10 mg/g) for tetracycline compared with PBB. The effects of initial tetracycline concentration, pH, temperature, and Fe-PBB dose on the adsorption removal of tetracycline from water were systematically investigated and optimized using a statistical experimental design and response surface methodology. The empirical relationship between the experimental factors and tetracycline removal was modeled, statistically validated through the analysis of variance, and used to predict the optimal conditions for adsorption removal of tetracycline. We found that ≥ 95% of the tetracycline can be removed at a tetracycline concentration of 1 mg/L, pH of 7, temperature of 50 °C, and a Fe-PBB dose of 2 g/L. The adsorption isotherm modeling study suggests that the adsorption of tetracycline can be attributed to the pore filling phenomenon and multilayer adsorption on the Fe-PBB. A thermodynamics study showed that the adsorption occurs spontaneously with an endothermic reaction.
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Affiliation(s)
- Qammer Zaib
- School of Civil and Environmental Engineering, University of Ulsan, Daehak-ro 93, Nam-gu, Ulsan, 44610, Republic of Korea
| | - Urjinlkham Ryenchindorj
- School of Civil and Environmental Engineering, University of Ulsan, Daehak-ro 93, Nam-gu, Ulsan, 44610, Republic of Korea
| | - Agusta Samodra Putra
- Department of Chemical Engineering, Ulsan College, Daehak-ro 57, Nam-gu, Ulsan, 44610, Republic of Korea
- Research Center for Sustainable Production System and Life Cycle Assessment, National Research and Innovation Agency, PUSPIPTEK Area, Serpong, 15314, Indonesia
| | - Daeseung Kyung
- School of Civil and Environmental Engineering, University of Ulsan, Daehak-ro 93, Nam-gu, Ulsan, 44610, Republic of Korea
| | - Hung-Suck Park
- School of Civil and Environmental Engineering, University of Ulsan, Daehak-ro 93, Nam-gu, Ulsan, 44610, Republic of Korea.
- Department of Chemical Engineering, Ulsan College, Daehak-ro 57, Nam-gu, Ulsan, 44610, Republic of Korea.
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Rezania S, Mojiri A, Park J, Nawrot N, Wojciechowska E, Marraiki N, Zaghloul NSS. Removal of lead ions from wastewater using lanthanum sulfide nanoparticle decorated over magnetic graphene oxide. Environ Res 2022; 204:111959. [PMID: 34474032 DOI: 10.1016/j.envres.2021.111959] [Citation(s) in RCA: 4] [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: 06/30/2021] [Revised: 08/18/2021] [Accepted: 08/22/2021] [Indexed: 06/13/2023]
Abstract
In this study, the new lanthanum sulfide nanoparticle (La2S3) was synthesized and incorporated onto magnetic graphene oxide (MGO) sheets surface to produce potential adsorbent (MGO@LaS) for efficient removal of lead ions (Pb2+) from wastewater. The synthesized MGO@LaS adsorbent was characterized using Fourier transform infrared spectroscopy, field emission scanning electron microscopy and energy-dispersive X-ray spectroscopy. The effective parameters on the adsorption process including solution pH (~5), adsorbent dosage (20 mg), contact time (40 min), initial Pb2+ concentration and temperature were studied. The removal efficiency was obtained >95% for lead ions at pH 5 with 20 mg adsorbent. To validate the adsorption rate and mechanism, the kinetic and thermodynamic models were studied based on experimental data. The Langmuir isotherm model was best fitted to initial equilibrium concentration with a maximum adsorption capacity of 123.46 mg/g. This indicated a monolayer adsorption pattern for Pb2+ ions over MGO@LaS. The pseudo-second-order as the kinetic model was best fitted to describe the adsorption rate due to high R2 > 0.999 as compared first-order. A thermodynamic model suggested a chemisorption and physisorption adsorption mechanism for Pb2+ ions uptake into MGO@LaS at different temperatures; ΔG° < -5.99 kJ mol-1 at 20 °C and ΔG° -18.2 kJ mol-1 at 45 °C. The obtained results showed that the novel nanocomposite (MGO@LaS) can be used as an alternative adsorbent in wastewater treatment.
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Affiliation(s)
- Shahabaldin Rezania
- Department of Environment and Energy, Sejong University, Seoul, 05006, South Korea.
| | - Amin Mojiri
- Department of Civil and Environmental Engineering, Graduate School of Advanced Science and Engineering, Hiroshima University, 1-4-1 Kagamiyama, Higashihiroshima, 739-8527, Japan
| | - Junboum Park
- Department of Civil and Environmental Engineering, Seoul National University, Seoul, South Korea
| | - Nicole Nawrot
- Gdańsk University of Technology, Faculty of Civil and Environmental Engineering, Narutowicza 11/12, 80-233, Gdańsk, Poland
| | - Ewa Wojciechowska
- Gdańsk University of Technology, Faculty of Civil and Environmental Engineering, Narutowicza 11/12, 80-233, Gdańsk, Poland
| | - Najat Marraiki
- Department of Botany and Microbiology, College of Science, King Saud University, P.O. 2455, Riyadh, 11451, Saudi Arabia
| | - Nouf S S Zaghloul
- Bristol Centre for Functional Nanomaterials, HH Wills Physics Laboratory, Tyndall Avenue, University of Bristol, Bristol, BS8 1FD, UK
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Zhang D, Huang Y, Oshita K, Takaoka M, Wang Q, Sheng C, Lin Z. Liquefied dimethyl ether based multi-stage extraction for high efficient oil recovery from spent bleaching clay. Waste Manag 2021; 136:204-212. [PMID: 34700160 DOI: 10.1016/j.wasman.2021.09.033] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [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: 03/26/2021] [Revised: 08/26/2021] [Accepted: 09/24/2021] [Indexed: 06/13/2023]
Abstract
With the increasing production of spent bleaching clay (SBC), the recovery of the waste oil in SBC is becoming an important and urgent needs for our environment and economy. In this research, we have developed a new effective recovery technique to recover oil from SBC by use of liquefied dimethyl ether (DME). Over 65 wt% oil and 81% wt.% oil are efficiently recovered from SBC under equilibrium single-stage extraction conditions and multi-stage extraction conditions, respectively based on the systematically investigation to the effects of the DME/SBC ratio, extraction time, stirring speed and extraction stage number on oil recovery via a batch extractor. Compared with using other extraction solvents, the extraction solvent DME can be reused without heating and therefore significantly reduce the energy consumption during the oil recovery process. In addition, the quantitative oil extraction relationship is derived from the adsorption equilibrium model and is well verified by experimental results. The results show a great potential for using this oil recovery technique in SBC as well as in the large amount of oily sludge and oil sands.
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Affiliation(s)
- Dong Zhang
- Department of Environmental Science and Technology, School of Energy and Environment, Southeast University, Sipailou 2, Nanjing 210096, China; Department of Environmental Engineering, Graduate School of Engineering, Kyoto University, Cluster C, Kyoto daigaku-Katsura, Nishikyo-ku, Kyoto 615-8540, Japan
| | - Ying Huang
- Department of Environmental Science and Technology, School of Energy and Environment, Southeast University, Sipailou 2, Nanjing 210096, China.
| | - Kazuyuki Oshita
- Department of Environmental Engineering, Graduate School of Engineering, Kyoto University, Cluster C, Kyoto daigaku-Katsura, Nishikyo-ku, Kyoto 615-8540, Japan.
| | - Masaki Takaoka
- Department of Environmental Engineering, Graduate School of Engineering, Kyoto University, Cluster C, Kyoto daigaku-Katsura, Nishikyo-ku, Kyoto 615-8540, Japan
| | - Quan Wang
- Department of Environmental Engineering, Graduate School of Engineering, Kyoto University, Cluster C, Kyoto daigaku-Katsura, Nishikyo-ku, Kyoto 615-8540, Japan
| | - Changdong Sheng
- Department of Environmental Science and Technology, School of Energy and Environment, Southeast University, Sipailou 2, Nanjing 210096, China
| | - Zizeng Lin
- Civil College, Nanjing Forest University, No.159, Longpan Road, Nanjing 210037, China
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Otieno AO, Home PG, Raude JM, Murunga SI, Ngumba E, Ojwang DO, Tuhkanen T. Pineapple peel biochar and lateritic soil as adsorbents for recovery of ammonium nitrogen from human urine. J Environ Manage 2021; 293:112794. [PMID: 34038825 DOI: 10.1016/j.jenvman.2021.112794] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [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: 02/26/2021] [Revised: 04/16/2021] [Accepted: 05/13/2021] [Indexed: 06/12/2023]
Abstract
Human urine is a rich source of nitrogen which can be captured to supplement the existing sources of nitrogen fertilizers thus contributing to enhanced crop production. However, urine is the major contributor of macronutrients in municipal wastewater flows resulting into eutrophication of the receiving water bodies. Herein, pineapple peel biochar (PPB), and lateritic soil (LS) adsorbents were prepared for the safe removal of ammonium nitrogen (NH4+-N) from human urine solutions. Physicochemical properties of PPB, and LS were characterized by scanning electron microscopy-energy dispersive spectroscopy (SEM-EDS), X-ray powder diffraction (XRD), Fourier transform infrared spectroscopy (FTIR) and thermogravimetric analysis (TGA) to investigate the relationship of their properties with NH4+-N adsorption. Langmuir, Freundlich, and Dubinin-Radushkevich (D-R) isotherm models were employed to correlate the experimental equilibrium adsorption data. The effect of contact time and initial concentration of NH4+-N adsorption was also evaluated. The D-R isotherm model best described the behaviour of NH4+-N adsorption on both PPB and LS based on the coefficient of correlation values. This model showed that the adsorption of NH4+-N on both samples was a physical process with PPB and LS having mean surface adsorption energies of 1.826 × 10-2, and 1.622 × 10-2 kJ/mol, respectively. The PPB exhibited a slightly higher adsorption capacity for NH4+-N (13.40 mg/g) than LS (10.73 mg/g) with the difference attributed to its higher surface area and porosity. These values are good indicators for assessing the effectiveness of the materials for adsorption of NH4+-N from human urine.
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Affiliation(s)
- Austine O Otieno
- Soil, Water and Environmental Engineering Department (SWEED), Jomo Kenyatta University of Agriculture and Technology, P.O. Box 62000-00200, Nairobi, Kenya; Department of Geoscience and the Environment (DGSE), Technical University of Kenya, P.O. Box 52428-00200, Nairobi, Kenya.
| | - Patrick G Home
- Soil, Water and Environmental Engineering Department (SWEED), Jomo Kenyatta University of Agriculture and Technology, P.O. Box 62000-00200, Nairobi, Kenya
| | - James M Raude
- Soil, Water and Environmental Engineering Department (SWEED), Jomo Kenyatta University of Agriculture and Technology, P.O. Box 62000-00200, Nairobi, Kenya
| | - Sylvia I Murunga
- Agricultural and Biosystems Engineering Department (ABED), Jomo Kenyatta University of Agriculture and Technology, P.O. Box 62000-00200, Nairobi, Kenya
| | - Elijah Ngumba
- Department of Chemistry, Jomo Kenyatta University of Agriculture and Technology, P.O. Box 62000-00200, Nairobi, Kenya
| | - Dickson O Ojwang
- Department of Chemistry - Ångström Laboratory, Uppsala University, Box 538, SE-751 21, Uppsala, Sweden
| | - Tuula Tuhkanen
- Department of Biological and Environmental Science, University of Jyvaskyla, P.O. Box 35, FI-40014, Finland
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Azadegan F, Esmaeili Bidhendi M, Badiei A, Lu S, Sotoudehnia Korrani Z, Rezania S. Removal of mercury ions from aqueous by functionalized LUS-1 with Bis [3-(triethoxysilyl) propyl] tetrasulfide as an effective nanocomposite using response surface methodology (RSM). Environ Sci Pollut Res Int 2021; 30:10.1007/s11356-021-15021-y. [PMID: 34185274 DOI: 10.1007/s11356-021-15021-y] [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: 03/14/2021] [Accepted: 06/16/2021] [Indexed: 06/13/2023]
Abstract
In this study, LUS-1, as a mesoporous silica material, was functionalized using sulfur-containing ligand (Bis [3-(triethoxysilyl) propyl] tetrasulfide, TESPT) and used for mercury removal from the aqueous solution. Different characterizations such as N2 adsorption-desorption (BET), TGA, XRD, FT-IR, and SEM were used to verify the nanocomposite synthesis. In addition, the effects of several independent parameters like pH, the contact time of reaction, and adsorbent dose on the removal efficiency of mercury from aqueous in a batch system were studied using response surface methodology (RSM). Based on the results and after both theoretical and experimental studies, the optimum conditions using the LUS-1-TESPT were contact time of reaction of 23.16 min, sorbent dose of 51.12 mg, and pH of 4.5. The kinetic and isotherm models for the adsorption process showed a maximum adsorption capacity of adsorbent which was 136.73 mg g-1 with 99% removal of Hg(II) via the Langmuir model. Meanwhile, the sorbent's reusability and efficiency verified that the sorbent could be used five times after recovery with 99% efficiency.
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Affiliation(s)
- Farhang Azadegan
- State Environmental Protection Key Laboratory of Environmental Risk Assessment and Control on Chemical Process, East China University of Science and Technology, Shanghai, 200237, China
| | | | - Alireza Badiei
- School of Chemistry, College of Science, University of Tehran, Tehran, Iran
- Nanobiomedicine Center of Excellence, Nanoscience and Nanotechnology Research Center, University of Tehran, Tehran, Iran
| | - Shuguang Lu
- State Environmental Protection Key Laboratory of Environmental Risk Assessment and Control on Chemical Process, East China University of Science and Technology, Shanghai, 200237, China
- Shanghai Institute of Pollution Control and Ecological Security, Shanghai, 200098, China
| | | | - Shahabaldin Rezania
- Department of Environment and Energy, Sejong University, Seoul, 05006, South Korea.
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Fallah Z, Roberts EPL. Combined adsorption/regeneration process for the removal of trace emulsified hydrocarbon contaminants. Chemosphere 2019; 230:596-605. [PMID: 31125888 DOI: 10.1016/j.chemosphere.2019.04.224] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [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: 01/21/2019] [Revised: 04/27/2019] [Accepted: 04/30/2019] [Indexed: 06/09/2023]
Abstract
In this study a process of adsorption and electrochemical regeneration was evaluated for its efficiency in removing low concentrations of emulsified oil from produced water, which is generated as a by-product from the thermal in-situ production of heavy oil. Adsorption behavior was investigated using synthetic model emulsions and samples of produced water; theoretical models were applied to the adsorption equilibrium and kinetics. It was demonstrated that the rate of the adsorption process was controlled by external mass transport, with no contribution from intra-particle diffusion. The non-porous structure of the Graphite Intercalation Compound (GIC) adsorbent led to effective and fast adsorption of oil in less than 30 min. Based on the cryo-SEM imaging and EDX phase mapping, the underlying adsorption mechanism was envisioned in the frame of adhesion and spreading of the emulsified oil droplets on the surface of the predominately hydrophobic GIC surface. The adsorptive capacity of the GIC was 100% recoverable by electrochemical regeneration. Energy consumption for the adsorbent regeneration process was found to be 22 kWh per kg of COD removed for treatment of the synthetic emulsion and 36 kWh per kg of COD for produced water.
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Affiliation(s)
- Zohreh Fallah
- University of Calgary, Department of Chemical and Petroleum Engineering, 2500 University Drive NW, Calgary, AB T2N 1N4, Canada
| | - Edward P L Roberts
- University of Calgary, Department of Chemical and Petroleum Engineering, 2500 University Drive NW, Calgary, AB T2N 1N4, Canada.
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Li G, Cai W, Zhao R, Hao L. Electrosorptive removal of salt ions from water by membrane capacitive deionization (MCDI): characterization, adsorption equilibrium, and kinetics. Environ Sci Pollut Res Int 2019; 26:17787-17796. [PMID: 31030403 DOI: 10.1007/s11356-019-05147-5] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [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: 09/15/2018] [Accepted: 04/09/2019] [Indexed: 06/09/2023]
Abstract
Capacitive deionization (CDI) was demonstrated to be an affordable technology for reduction of salt concentrations in brackish water. In this study, a novel membrane capacitive deionization (MCDI) cell was assembled by incorporating ion exchange membranes into the CDI cell which was built with high-adsorption electrodes based on ordered mesoporous carbon. The synthesized mesoporous carbon electrode was fully characterized. The simultaneous analysis of the electrosorption capacity and adsorption/desorption kinetics was evaluated by using real power plant desulfurization wastewater. The ordered mesoporous carbon was favorable for salt ion electrosorption, and the best performance was obtained by using MCDI which improved the removal efficiency of total dissolved solids (TDSs) from 65 to 82%. The total hardness and alkalinity of the effluent after treatment could meet the requirement of water quality standard for industries. Langmuir isotherm and pseudo-first-order kinetic models were found to be in best agreement with experimental results of salt ion electrosorption. The selective transport of ions between the electrode surface and bulk solution due to the ion exchange membranes resulted in a better desalination performance of MCDI. The results presented in this paper could be used for developing new electrode materials of MCDI for desalination from water.
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Affiliation(s)
- Guiju Li
- College of Marine Science and Environment, Tianjin University of Science and Technology, Tianjin, 300457, China
- Tianjin Key Laboratory of Marine Resources and Chemistry, Tianjin, 300457, China
| | - Wenbo Cai
- College of Marine Science and Environment, Tianjin University of Science and Technology, Tianjin, 300457, China
| | - Ruihua Zhao
- College of Marine Science and Environment, Tianjin University of Science and Technology, Tianjin, 300457, China
- Tianjin Key Laboratory of Marine Resources and Chemistry, Tianjin, 300457, China
| | - Linlin Hao
- College of Marine Science and Environment, Tianjin University of Science and Technology, Tianjin, 300457, China.
- Tianjin Key Laboratory of Marine Resources and Chemistry, Tianjin, 300457, China.
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12
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Ocampo-Perez R, Padilla-Ortega E, Medellin-Castillo NA, Coronado-Oyarvide P, Aguilar-Madera CG, Segovia-Sandoval SJ, Flores-Ramírez R, Parra-Marfil A. Synthesis of biochar from chili seeds and its application to remove ibuprofen from water. Equilibrium and 3D modeling. Sci Total Environ 2019; 655:1397-1408. [PMID: 30577131 DOI: 10.1016/j.scitotenv.2018.11.283] [Citation(s) in RCA: 32] [Impact Index Per Article: 6.4] [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: 08/07/2018] [Revised: 10/17/2018] [Accepted: 11/19/2018] [Indexed: 06/09/2023]
Abstract
In this work chili seeds (Capsicum annuum) were used as raw material in the synthesis of biochar at temperatures between 400 and 600 °C. The samples were chemically, texturally and morphologically characterized and their properties were correlated with the calcination temperature. The adsorption mechanism of IBP was elucidated by analyzing the effect of solution pH, ionic strength and temperature, whereas that, the intraparticle diffusion mechanism was clarified through the application of a 3D diffusional model. The results evidenced that raising the pyrolysis temperature promotes a greater content of disordered graphitic carbon (51.6-85.02%) with small surface area (0.52-0.18 m2/g) and low quantity of functional groups. The adsorption study demonstrated that the biochar synthesized at 600 °C (C600) enhances the adsorption capacity >50 folds compared with chili seeds. Moreover, at pH = 7 the adsorption mechanism is governed by π-acceptor and attractive electrostatic interactions, whereas at basic pH the main adsorption mechanism is π-acceptor. Additionally, hydrophobic interactions become important by increasing the presence of NaCl. The application of 3D diffusional model based on surface diffusion interpreted clearly the kinetic curves obtaining values of Ds ranging from 2.31 × 10-8-2.51 × 10-8 cm2 s-1. Besides, it was determined that intraparticle mass flux is larger along the shortest axis of the seed, and always directed toward the particle center. The maximum mass flux takes place in the center of particle, and it advances like a moving front as time was increased.
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Affiliation(s)
- R Ocampo-Perez
- Centro de Investigación y Estudios de Posgrado, Facultad de Ciencias Químicas, Universidad Autónoma de San Luis Potosí, Av. Salvador Nava No.6, San Luis Potosí, SLP 78210, Mexico.
| | - E Padilla-Ortega
- Centro de Investigación y Estudios de Posgrado, Facultad de Ciencias Químicas, Universidad Autónoma de San Luis Potosí, Av. Salvador Nava No.6, San Luis Potosí, SLP 78210, Mexico
| | - N A Medellin-Castillo
- Centro de Investigación y Estudio de Posgrado, Facultad de Ingeniería, Universidad Autónoma de San Luis Potosí, Av. Salvador Nava No. 8 Zona Universitaria, San Luis Potosí, SLP 78290, Mexico
| | - P Coronado-Oyarvide
- Centro de Investigación y Estudios de Posgrado, Facultad de Ciencias Químicas, Universidad Autónoma de San Luis Potosí, Av. Salvador Nava No.6, San Luis Potosí, SLP 78210, Mexico
| | - C G Aguilar-Madera
- Facultad de Ciencias de la Tierra, Universidad Autónoma de Nuevo León, Ex Hacienda de Guadalupe, Linares, NL 67700, Mexico
| | - S J Segovia-Sandoval
- Centro de Investigación y Estudio de Posgrado, Facultad de Ingeniería, Universidad Autónoma de San Luis Potosí, Av. Salvador Nava No. 8 Zona Universitaria, San Luis Potosí, SLP 78290, Mexico
| | - R Flores-Ramírez
- CONACYT Research Fellow, Coordinación para la Innovación y Aplicación de la Ciencia y la Tecnología (CIACYT), Mexico
| | - A Parra-Marfil
- Centro de Investigación y Estudios de Posgrado, Facultad de Ciencias Químicas, Universidad Autónoma de San Luis Potosí, Av. Salvador Nava No.6, San Luis Potosí, SLP 78210, Mexico
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13
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Derylo-Marczewska A, Blachnio M, Marczewski AW, Seczkowska M, Tarasiuk B. Phenoxyacid pesticide adsorption on activated carbon - Equilibrium and kinetics. Chemosphere 2019; 214:349-360. [PMID: 30267908 DOI: 10.1016/j.chemosphere.2018.09.088] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [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: 07/10/2018] [Revised: 09/11/2018] [Accepted: 09/16/2018] [Indexed: 06/08/2023]
Abstract
The adsorption of herbicides belonging to the group of halogenated phenoxyacids on the activated carbon was studied. They are differentiated in terms of quantity and type of functional groups (such as chloride, bromide, fluoride) and their position on an aromatic ring. The experimental equilibrium data were analyzed using adsorption isotherm equations taking into account energetic heterogeneity of the adsorption systems. The calculated concentration profiles from the kinetic data were discussed applying two diffusion models, MOE, f-MOE and multi-exponential equations. The dependences between the properties of adsorbates, adsorption uptake and rate were analyzed. The adsorption affinity of pesticides was correlated with adsorbate hydrophobicity, character of functional group, molecular structure. The applicability of kinetic models and equations was investigated; the assumptions of the models were analyzed with regard to consistency with adsorption mechanism. Similarity of adsorption mechanism was found for all adsorbates confirmed by similarity of kinetic curves and corresponding distributions of rate coefficients. The differences in kinetic profiles were attributed to differentiation of herbicide's molecules - number and type of functional groups and their positions on aromatic ring.
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Affiliation(s)
- Anna Derylo-Marczewska
- Faculty of Chemistry, Maria Curie-Sklodowska University, Maria Curie Sklodowska Sq. 3, 20-031 Lublin, Poland.
| | - Magdalena Blachnio
- Faculty of Chemistry, Maria Curie-Sklodowska University, Maria Curie Sklodowska Sq. 3, 20-031 Lublin, Poland.
| | - Adam Wojciech Marczewski
- Faculty of Chemistry, Maria Curie-Sklodowska University, Maria Curie Sklodowska Sq. 3, 20-031 Lublin, Poland.
| | - Malgorzata Seczkowska
- Faculty of Chemistry, Maria Curie-Sklodowska University, Maria Curie Sklodowska Sq. 3, 20-031 Lublin, Poland.
| | - Bogdan Tarasiuk
- Faculty of Chemistry, Maria Curie-Sklodowska University, Maria Curie Sklodowska Sq. 3, 20-031 Lublin, Poland.
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Srikantan C, Suraishkumar GK, Srivastava S. Effect of light on the kinetics and equilibrium of the textile dye (Reactive Red 120) adsorption by Helianthus annuus hairy roots. Bioresour Technol 2018; 257:84-91. [PMID: 29486410 DOI: 10.1016/j.biortech.2018.02.075] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [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: 11/15/2017] [Revised: 02/14/2018] [Accepted: 02/16/2018] [Indexed: 06/08/2023]
Abstract
The study demonstrates for the first time that light influences the adsorption equilibrium and kinetics of a dye by root culture system. The azo dye (Reactive Red 120) adsorption by the hairy roots of H. annuus followed a pseudo first-order kinetic model and the adsorption equilibrium parameters were best estimated using Langmuir isotherm. The maximum dye adsorption capacity of the roots increased 6-fold, from 0.26 mg g-1 under complete dark conditions to 1.51 mg g-1 under 16/8 h light/dark photoperiod. Similarly, adsorption rate of the dye and removal (%) also increased in the presence of light, irrespective of the initial concentration of the dye (20-110 mg L-1). The degradation of the azo dye upon adsorption by the hairy roots of H. annuus was also confirmed. In addition, a strategy for simultaneous dye removal and increased alpha-tocopherol (industrially relevant) production by H. annuus hairy root cultures has been proposed and demonstrated.
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Affiliation(s)
- Chitra Srikantan
- Department of Biotechnology, Bhupat & Jyoti Mehta School of Biosciences, Indian Institute of Technology Madras, Chennai 600 036, India
| | - G K Suraishkumar
- Department of Biotechnology, Bhupat & Jyoti Mehta School of Biosciences, Indian Institute of Technology Madras, Chennai 600 036, India
| | - Smita Srivastava
- Department of Biotechnology, Bhupat & Jyoti Mehta School of Biosciences, Indian Institute of Technology Madras, Chennai 600 036, India.
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Yangui A, Abderrabba M. Towards a high yield recovery of polyphenols from olive mill wastewater on activated carbon coated with milk proteins: Experimental design and antioxidant activity. Food Chem 2018; 262:102-9. [PMID: 29751896 DOI: 10.1016/j.foodchem.2018.04.091] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2017] [Revised: 03/26/2018] [Accepted: 04/22/2018] [Indexed: 11/21/2022]
Abstract
Activated carbon coated with milk proteins was used for the removal and recovery of phenolic compounds from actual olive mill wastewater (OMW). The extraction of polyphenols using the new adsorbent based on natural coating agent has significant potential compared with traditional extraction methods, as it significantly increases the extraction yield (80%) and overall efficiencies of the process for total phenols (75.4%) and hydroxytyrosol (90.6%) which is the most valuable compound. Complete discussions on the adsorption isotherms, kinetic and thermodynamic were performed and the optimum adsorption variables were investigated using the response surface methodology and the central composite experimental design. The extracted polyphenols exhibited a high antioxidant activity and a fast scavenging effect on DPPH free radical. The strategy devised in this work for polyphenol extraction using modified activated carbon with biological coating agent is of simple design, very effective and ensure the recovery of highly antioxidant extract.
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Yoon JW, Yoon TU, Kim EJ, Kim AR, Jung TS, Han SS, Bae YS. Highly selective adsorption of CO over CO 2 in a Cu(I)-chelated porous organic polymer. J Hazard Mater 2018; 341:321-327. [PMID: 28800566 DOI: 10.1016/j.jhazmat.2017.07.065] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/19/2017] [Revised: 07/25/2017] [Accepted: 07/28/2017] [Indexed: 06/07/2023]
Abstract
Cu(I) species were successfully chelated to nitrogen atoms in a nitrogen-rich porous organic polymer (SNW-1) by mixing with a CuCl solution (Scheme 1). Although pristine SNW-1 adsorbs CO2 better than CO, Cu(I)-incorporated SNW-1 (nCu(I)@SNW-1) shows selective CO adsorption over CO2 because of the π-complexation of CO with Cu(I). To the best of our knowledge, this is the first CO/CO2 selectivity observed for POP-based materials. 1.3Cu(I)@SNW-1 exhibits high CO/CO2 selectivity (23) at 1bar and a large CO working capacity (0.6mmol/g) at 0.1-1bar. Moreover, the breakthrough and thermogravimetric experiments show that 1.3Cu(I)@SNW-1 can effectively separate CO from CO2 under dynamic mixture conditions and can be easily regenerated under mild regeneration conditions without heating the column. Furthermore, 1.3Cu(I)@SNW-1 exhibited a good stability under exposure to atmospheric air for 3h or 9h. These results suggest that chelating Cu(I) species to a nitrogen-rich porous organic polymer can be an efficient strategy to separate and recover CO from CO/CO2 mixtures.
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Affiliation(s)
- Jung Woon Yoon
- Department of Chemical and Biomolecular Engineering, Yonsei University, 50 Yonsei-ro, Seodaemun-gu, Seoul, 03722, Republic of Korea
| | - Tae-Ung Yoon
- Department of Chemical and Biomolecular Engineering, Yonsei University, 50 Yonsei-ro, Seodaemun-gu, Seoul, 03722, Republic of Korea
| | - Eun-Jung Kim
- Graduate School of Integrated Engineering, Yonsei University, 50 Yonsei-ro, Seodaemun-gu, Seoul, 03722, Republic of Korea
| | - Ah-Reum Kim
- Department of Chemical and Biomolecular Engineering, Yonsei University, 50 Yonsei-ro, Seodaemun-gu, Seoul, 03722, Republic of Korea
| | - Tae-Sung Jung
- Clean Fuel Laboratory, Korea Institute of Energy Research, 152 Gajeong-ro, Yuseong-gu, Daejeon 34129, Republic of Korea
| | - Sang-Sup Han
- Clean Fuel Laboratory, Korea Institute of Energy Research, 152 Gajeong-ro, Yuseong-gu, Daejeon 34129, Republic of Korea
| | - Youn-Sang Bae
- Department of Chemical and Biomolecular Engineering, Yonsei University, 50 Yonsei-ro, Seodaemun-gu, Seoul, 03722, Republic of Korea; Graduate School of Integrated Engineering, Yonsei University, 50 Yonsei-ro, Seodaemun-gu, Seoul, 03722, Republic of Korea.
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17
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Lee SC, Park S. Removal of furan and phenolic compounds from simulated biomass hydrolysates by batch adsorption and continuous fixed-bed column adsorption methods. Bioresour Technol 2016; 216:661-8. [PMID: 27289057 DOI: 10.1016/j.biortech.2016.06.007] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [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: 04/07/2016] [Revised: 06/01/2016] [Accepted: 06/02/2016] [Indexed: 05/05/2023]
Abstract
It has been proposed to remove all potential inhibitors and sulfuric acid in biomass hydrolysates generated from dilute-acid pretreatment of biomass, based on three steps of sugar purification process. This study focused on its first step in which furan and phenolic compounds were selectively removed from the simulated hydrolysates using activated charcoal. Batch adsorption experiments demonstrated that the affinity of activated charcoal for each component was highest in the order of vanillic acid, 4-hydroxybenzoic acid, furfural, acetic acid, sulfuric acid, and xylose. The affinity of activated charcoal for furan and phenolic compounds proved to be significantly higher than that of the other three components. Four separation strategies were conducted with a combination of batch adsorption and continuous fixed-bed column adsorption methods. It was observed that xylose loss was negligible with near complete removal of furan and phenolic compounds, when at least one fixed-bed column adsorption was implemented in the strategy.
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Affiliation(s)
- Sang Cheol Lee
- Department of Chemical Engineering, Kunsan National University, 558 Daehak-ro, Gunsan, Jeollabuk-do 54150, Republic of Korea.
| | - Sunkyu Park
- Department of Forest Biomaterials, North Carolina State University, 2820 Faucette Drive, Raleigh, NC 27695, USA
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Nam S, Namkoong W, Kang JH, Park JK, Lee N. Adsorption characteristics of siloxanes in landfill gas by the adsorption equilibrium test. Waste Manag 2013; 33:2091-2098. [PMID: 23684695 DOI: 10.1016/j.wasman.2013.03.024] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.3] [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: 10/01/2012] [Revised: 03/04/2013] [Accepted: 03/30/2013] [Indexed: 06/02/2023]
Abstract
Due to the increase in energy cost by constantly high oil prices and the obligation to reduce greenhouse effect gases, landfill gas is frequently used as an alternative energy source for producing heat and electricity. Most of landfill gas utility facilities, however, are experiencing problems controlling siloxanes from landfill gas as their catalytic oxidizers are becoming fouled by silicon dioxide dust. To evaluate adsorption characteristics of siloxanes, an adsorption equilibrium test was conducted and parameters in the Freundlich and Langmuir isotherms were analyzed. Coconut activated carbon (CA1), coal activated carbon (CA2), impregnated activated carbon (CA3), silicagel (NCA1), and activated alumina (NCA2) were used for the adsorption of the mixed siloxane which contained hexamethyldisiloxane (L2), octamethylcyclotetrasiloxane (D4), and decamethylcyclopentasiloxane (D5). L2 had higher removal efficiency in noncarbon adsorbents compared to carbon adsorbents. The application of Langmuir and Freundlich adsorption isotherm demonstrated that coconut based CA1 and CA3 provided higher adsorption capacity on L2. And CA2 and NCA1 provided higher adsorption capacity on D4 and D5. Based on the experimental results, L2, D4, and D5 were converted by adsorption and desorption in noncarbon adsorbents. Adsorption affinity of siloxane is considered to be affect by the pore size distribution of the adsorbents and by the molecular size of each siloxane.
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Affiliation(s)
- Sangchul Nam
- Department of Environmental Engineering, Konkuk University, Hwayang-Dong, Gwangjin-Gu, Seoul 143-701, Republic of Korea
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