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Huang Y, Liu Z, Liu H, Ma C, Chen W, Huangfu X. Treatment of wastewater containing thallium(I) by long-term operated manganese sand filter: Synergistic action of MnOx and MnOM. THE SCIENCE OF THE TOTAL ENVIRONMENT 2024; 908:168085. [PMID: 37914136 DOI: 10.1016/j.scitotenv.2023.168085] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/30/2023] [Revised: 10/05/2023] [Accepted: 10/21/2023] [Indexed: 11/03/2023]
Abstract
The long-term and stable removal of thallium (Tl) from industrial wastewater generated by mining and smelting operations remains challenging. While sand filters are commonly applied for the simultaneous removal of Mn(II) and other heavy metals, they have limited efficacy in treating Tl-contaminated wastewater. To address this gap, we operated a lab-scale Mn sand filter (MF) without added microorganisms to investigate the efficiency and mechanisms of Mn(II) and Tl(I) removal. Trends in effluent Mn(II) and Tl(I) concentrations indicated three operational stages: start-up, developing and maturation. Over time, the removal efficiency of Tl(I) gradually improved, plateauing at approximately 80 % eventually. Throughout operation, Tl(I) was sequestrated via surface complexation and ion exchange. Besides, enrichment of Sphingobium and other typical manganese oxidizing microorganisms (MnOM) during operation facilitated Mn(II) and Tl(I) oxidation and sequestration by generating biogenic manganese oxides (BioMnOx). Additionally, the accurate control of water quality and operating conditions during operation could also enhance removal efficiency. In summary, physicochemical actions of Mn oxides and biochemical actions of microorganisms synergistically contributed to the sequestration of Mn(II) and Tl(I). These findings provided a novel and sustainable method for the long-term and stable treatment of industrial wastewater containing thallium.
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Affiliation(s)
- Yuheng Huang
- Key Laboratory of Eco-Environments in Three Gorges Reservoir Region, Ministry of Education, College of Environment, and Ecology, Chongqing University, Chongqing 400044, China
| | - Ziqiang Liu
- Key Laboratory of Eco-Environments in Three Gorges Reservoir Region, Ministry of Education, College of Environment, and Ecology, Chongqing University, Chongqing 400044, China
| | - Hongxia Liu
- Key Laboratory of Eco-Environments in Three Gorges Reservoir Region, Ministry of Education, College of Environment, and Ecology, Chongqing University, Chongqing 400044, China.
| | - Chengxue Ma
- State Key Laboratory of Urban Water Resource, and Environment, School of Municipal, and Environmental Engineering, Harbin Institute of Technology, Harbin 150090, China
| | - Wanpeng Chen
- Key Laboratory of Eco-Environments in Three Gorges Reservoir Region, Ministry of Education, College of Environment, and Ecology, Chongqing University, Chongqing 400044, China
| | - Xiaoliu Huangfu
- Key Laboratory of Eco-Environments in Three Gorges Reservoir Region, Ministry of Education, College of Environment, and Ecology, Chongqing University, Chongqing 400044, China.
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Huangfu X, Liu Z, Wang H, He Q, Liu H, Liu C. Highly inhibited transport of dissolved thallium(I) in manganese oxide-coated sand: Chemical condition effects and retention mechanisms. J Environ Sci (China) 2023; 129:104-114. [PMID: 36804227 DOI: 10.1016/j.jes.2022.09.041] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2022] [Revised: 09/14/2022] [Accepted: 09/28/2022] [Indexed: 06/18/2023]
Abstract
Thallium contamination in water can cause great danger to the environment. In this study, we synthesized manganese oxide-coated sand (MOCS) and investigated the transport and retention behaviors of Tl(I) in MOCS under different conditions. Characterization methods combined with a two-site nonequilibrium transport model were applied to explore the retention mechanisms. The results showed that Tl(I) mobility was strongly inhibited in MOCS media, and the retention capacity calculated from the fitted model was 510.41 mg/g under neutral conditions. The retention process included adsorption and oxidative precipitation by the manganese oxides coated on the sand surface. Cotransport with the same concentration of Mn(II) led to halving Tl(I) retention due to competition for reactive sites. Enhanced Tl(I) retention was observed under alkaline conditions, as increasing pH promoted electronegativity on the media surface. Moreover, the competitive cation Ca2+ significantly weakened Tl(I) retention by occupying adsorption sites. These findings provide new insights into understanding Tl(I) transport behavior in water-saturated porous media and suggest that manganese oxide-coated sand can be a cost-effective filter media for treating Tl-contaminated water.
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Affiliation(s)
- Xiaoliu Huangfu
- Key Laboratory of Eco-Environments in Three Gorges Reservoir Region, Ministry of Education, College of Environment and Ecology, Chongqing University, Chongqing 400044, China
| | - Ziqiang Liu
- Key Laboratory of Eco-Environments in Three Gorges Reservoir Region, Ministry of Education, College of Environment and Ecology, Chongqing University, Chongqing 400044, China
| | - Hainan Wang
- Key Laboratory of Eco-Environments in Three Gorges Reservoir Region, Ministry of Education, College of Environment and Ecology, Chongqing University, Chongqing 400044, China; State Key Laboratory of Pollution Control and Resource Reuse, School of Environment, Nanjing University, Nanjing 210023, China
| | - Qiang He
- Key Laboratory of Eco-Environments in Three Gorges Reservoir Region, Ministry of Education, College of Environment and Ecology, Chongqing University, Chongqing 400044, China
| | - Hongxia Liu
- Key Laboratory of Eco-Environments in Three Gorges Reservoir Region, Ministry of Education, College of Environment and Ecology, Chongqing University, Chongqing 400044, China.
| | - Caihong Liu
- Key Laboratory of Eco-Environments in Three Gorges Reservoir Region, Ministry of Education, College of Environment and Ecology, Chongqing University, Chongqing 400044, China
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Michel MM, Azizi M, Mirosław-Świątek D, Reczek L, Cieniek B, Sočo E. Significance of MnO 2 Type and Solution Parameters in Manganese Removal from Water Solution. Int J Mol Sci 2023; 24:ijms24054448. [PMID: 36901877 PMCID: PMC10003147 DOI: 10.3390/ijms24054448] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2023] [Revised: 02/06/2023] [Accepted: 02/21/2023] [Indexed: 02/26/2023] Open
Abstract
A very low concentration of manganese (Mn) in water is a critical issue for municipal and industrial water supply systems. Mn removal technology is based on the use of manganese oxides (MnOx), especially manganese dioxide (MnO2) polymorphs, under different conditions of pH and ionic strength (water salinity). The statistical significance of the impact of polymorph type (akhtenskite ε-MnO2, birnessite δ-MnO2, cryptomelane α-MnO2 and pyrolusite β-MnO2), pH (2-9) and ionic strength (1-50 mmol/L) of solution on the adsorption level of Mn was investigated. The analysis of variance and the non-parametric Kruskal-Wallis H test were applied. Before and after Mn adsorption, the tested polymorphs were characterized using X-ray diffraction, scanning electron microscope techniques and gas porosimetry analysis. Here we demonstrated the significant differences in adsorption level between MnO2 polymorphs' type and pH; however, the statistical analysis proves that the type of MnO2 has a four times stronger influence. There was no statistical significance for the ionic strength parameter. We showed that the high adsorption of Mn on the poorly crystalline polymorphs leads to the blockage of micropores in akhtenskite and, contrary, causes the development of the surface structure of birnessite. At the same time, no changes in the surfaces of cryptomelane and pyrolusite, the highly crystalline polymorphs, were found due to the very small loading by the adsorbate.
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Affiliation(s)
- Magdalena M. Michel
- Institute of Environmental Engineering, Warsaw University of Life Science, 02-787 Warsaw, Poland
| | - Mostafa Azizi
- Institute of Environmental Engineering, Warsaw University of Life Science, 02-787 Warsaw, Poland
- Correspondence:
| | - Dorota Mirosław-Świątek
- Institute of Environmental Engineering, Warsaw University of Life Science, 02-787 Warsaw, Poland
| | - Lidia Reczek
- Institute of Environmental Engineering, Warsaw University of Life Science, 02-787 Warsaw, Poland
| | - Bogumił Cieniek
- Institute of Materials Engineering, University of Rzeszow, 35-310 Rzeszow, Poland
| | - Eleonora Sočo
- Department of Inorganic and Analytical Chemistry, Faculty of Chemistry, Rzeszow University of Technology, 35-959 Rzeszow, Poland
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Fernandes del Pozo D, Ahmad A, Rehman U, Verliefde A, Nopens I. A novel CFD model to predict effluent solids concentration and pressure drop in deep bed granular filters for water treatment. Sep Purif Technol 2022. [DOI: 10.1016/j.seppur.2022.121232] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
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Maie N, Anzai S, Tokai K, Kakino W, Taruya H, Ninomiya H. Using oxygen/ozone nanobubbles for in situ oxidation of dissolved hydrogen sulfide at a residential tunnel-construction site. JOURNAL OF ENVIRONMENTAL MANAGEMENT 2022; 302:114068. [PMID: 34773779 DOI: 10.1016/j.jenvman.2021.114068] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/09/2021] [Revised: 11/01/2021] [Accepted: 11/03/2021] [Indexed: 06/13/2023]
Abstract
Hydrogen sulfide (H2S) is a toxic gas, and considerable research has been conducted for its control and removal from industrial wastewater and sewage water. However, no simple and practical technology is available for degrading H2S in situ at tunnel constructing sites. On May 11, 2020, an H2S blowout accident occurred in underground soil at a residential sewer-tunnel construction site in Iwakuni City, Yamaguchi Prefecture, Japan, filling the tunnel with high concentrations of H2S gas, causing the fatality of one worker owing to emphysema. River water flowing near the site was immediately introduced into the tunnel to trap the H2S gas, generating 652-m3 water that contained high concentrations (120 mg/L) of dissolved H2S in the tunnel. To safely and quickly remove H2S in situ, the contaminated water was treated with high-density oxygen and ozone nanobubbles (O2/O3-HDNBs) generated using the ultrafine pore method. Consequently, H2S was removed from the contaminated water in 3 days. This is the first successful application of O2/O3-HDNB technology for the in situ oxidation of H2S in environmental water at a construction site. This study reports the practical application of this advanced technology and the system performance.
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Affiliation(s)
- Nagamitsu Maie
- School of Veterinary Medicine, Kitasato University, 23-35-1 Higashi, Towada, 034-8628, Aomori, Japan.
| | - Satoshi Anzai
- Anzai-Kantetsu Inc., 3-1-16 Komaoka, Tsurumi-ku, Yokohama, 230-0071, Kanagawa, Japan
| | - Kengo Tokai
- Nittoc Construction Co., Ltd., 3-10-6 Higashi-Nihonbashi, Chuo-ku, 103-0004, Tokyo, Japan
| | - Wataru Kakino
- School of Veterinary Medicine, Kitasato University, 23-35-1 Higashi, Towada, 034-8628, Aomori, Japan
| | - Hiroyuki Taruya
- School of Veterinary Medicine, Kitasato University, 23-35-1 Higashi, Towada, 034-8628, Aomori, Japan
| | - Hideki Ninomiya
- Yamaguchi Earth Engineering Coop., 2-3-13 Hirano, Yamaguchi, 753-0015, Yamaguchi, Japan
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6
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Cao V, Alyoussef G, Gatcha-Bandjun N, Gwenzi W, Noubactep C. The key role of contact time in elucidating the mechanisms of enhanced decontamination by Fe 0/MnO 2/sand systems. Sci Rep 2021; 11:12069. [PMID: 34103590 PMCID: PMC8187491 DOI: 10.1038/s41598-021-91475-x] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2021] [Accepted: 05/26/2021] [Indexed: 11/20/2022] Open
Abstract
Metallic iron (Fe0) has shown outstanding performances for water decontamination and its efficiency has been improved by the presence of sand (Fe0/sand) and manganese oxide (Fe0/MnOx). In this study, a ternary Fe0/MnOx/sand system is characterized for its discoloration efficiency of methylene blue (MB) in quiescent batch studies for 7, 18, 25 and 47 days. The objective was to understand the fundamental mechanisms of water treatment in Fe0/H2O systems using MB as an operational tracer of reactivity. The premise was that, in the short term, both MnO2 and sand delay MB discoloration by avoiding the availability of free iron corrosion products (FeCPs). Results clearly demonstrate no monotonous increase in MB discoloration with increasing contact time. As a rule, the extent of MB discoloration is influenced by the diffusive transport of MB from the solution to the aggregates at the bottom of the vessels (test-tubes). The presence of MnOx and sand enabled the long-term generation of iron hydroxides for MB discoloration by adsorption and co-precipitation. Results clearly reveal the complexity of the Fe0/MnOx/sand system, while establishing that both MnOx and sand improve the efficiency of Fe0/H2O systems in the long-term. This study establishes the mechanisms of the promotion of water decontamination by amending Fe0-based systems with reactive MnOx.
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Affiliation(s)
- Viet Cao
- Faculty of Natural Sciences, Hung Vuong University, Nguyen Tat Thanh Street, Viet Tri, Phu Tho, 35120, Vietnam
| | - Ghinwa Alyoussef
- Angewandte Geologie, Universität Göttingen, Goldschmidtstraße 3, 37077, Göttingen, Germany
| | - Nadège Gatcha-Bandjun
- Department of Chemistry, Faculty of Science, University of Maroua, BP 46, Maroua, Cameroon
| | - Willis Gwenzi
- Biosystems and Environmental Engineering Research Group, Department of Agricultural and Biosystems Engineering, University of Zimbabwe, P.O. Box MP167, Mt. Pleasant, Harare, Zimbabwe
| | - Chicgoua Noubactep
- Angewandte Geologie, Universität Göttingen, Goldschmidtstraße 3, 37077, Göttingen, Germany.
- Centre for Modern Indian Studies (CeMIS), Universität Göttingen, Waldweg 26, 37073, Göttingen, Germany.
- Department of Water and Environmental Science and Engineering, Nelson Mandela African Institution of Science and Technology, P.O. Box 447, Arusha, Tanzania.
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7
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Efimova NV, Krasnopyorova AP, Yuhno GD, Sofronov DS, Rucki M. Uptake of Radionuclides 60Co, 137Cs, and 90Sr with α-Fe 2O 3 and Fe 3O 4 Particles from Aqueous Environment. MATERIALS 2021; 14:ma14112899. [PMID: 34071340 PMCID: PMC8199396 DOI: 10.3390/ma14112899] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/30/2021] [Revised: 05/21/2021] [Accepted: 05/26/2021] [Indexed: 11/16/2022]
Abstract
In the paper, investigation results of the uptake efficiency of radionuclides 60Co, 90Sr, and 137Cs dissolved in water onto iron oxides α-Fe2O3 and Fe3O4 are presented. It was found that sorption efficiency increased for higher pH values. Independent of the oxide nature, the uptake characteristics are the best toward 60Co and the worst toward 137Cs, forming the row as follows: 60Co > 90Sr > 137Cs. The highest sorption ability at pH 9 was found for magnetite Fe3O4, which was 93%, 73%, and 26% toward 60Co, 90Sr, and 137Cs, respectively, while the respective percentages for hematite α-Fe2O3 were 85%, 41%, and 18%. It was assumed that the main sorption mechanism was ion exchange. That may explain some decrease of the sorption efficiency in drinking water due to the interfering presence of magnesium and calcium cations. The obtained results indicated the feasibility of the tested sorbents and their merits, especially in terms of relatively high uptake coefficients, low costs, availability, and lack of toxicity.
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Affiliation(s)
- Natalya V. Efimova
- Department of Radiochemistry and Radioecology, V.N. Karazin Kharkiv National University, 4 Svobody Sq., 61022 Kharkiv, Ukraine; (N.V.E.); (A.P.K.); (G.D.Y.)
| | - Alla P. Krasnopyorova
- Department of Radiochemistry and Radioecology, V.N. Karazin Kharkiv National University, 4 Svobody Sq., 61022 Kharkiv, Ukraine; (N.V.E.); (A.P.K.); (G.D.Y.)
| | - Galina D. Yuhno
- Department of Radiochemistry and Radioecology, V.N. Karazin Kharkiv National University, 4 Svobody Sq., 61022 Kharkiv, Ukraine; (N.V.E.); (A.P.K.); (G.D.Y.)
| | - Dmitry S. Sofronov
- State Scientific Institution «Institute for Single Cristal», National Academy of Sciences, 60 Nauky Avenue, 61001 Kharkiv, Ukraine;
| | - Mirosław Rucki
- Faculty of Mechanical Engineering, Kazimierz Pulaski University of Technology and Humanities in Radom, ul. Stasieckiego 54, 26-600 Radom, Poland
- Correspondence:
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8
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Cao V, Alyoussef G, Gatcha-Bandjun N, Gwenzi W, Noubactep C. Characterizing the impact of MnO 2 addition on the efficiency of Fe 0/H 2O systems. Sci Rep 2021; 11:9814. [PMID: 33963252 PMCID: PMC8105408 DOI: 10.1038/s41598-021-89318-w] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2021] [Accepted: 04/21/2021] [Indexed: 11/23/2022] Open
Abstract
The role of manganese dioxide (MnO2) in the process of water treatment using metallic iron (Fe0/H2O) was investigated in quiescent batch experiments for t ≤ 60 d. MnO2 was used as an agent to control the availability of solid iron corrosion products (FeCPs) while methylene blue (MB) was an indicator of reactivity. The investigated systems were: (1) Fe0, (2) MnO2, (3) sand, (4) Fe0/sand, (5) Fe0/MnO2, and (6) Fe0/sand/MnO2. The experiments were performed in test tubes each containing 22.0 mL of MB (10 mg L−1) and the solid aggregates. The initial pH value was 8.2. Each system was characterized for the final concentration of H+, Fe, and MB. Results show no detectable level of dissolved iron after 47 days. Final pH values varied from 7.4 to 9.8. The MB discoloration efficiency varies from 40 to 80% as the MnO2 loading increases from 2.3 to 45 g L−1. MB discoloration is only quantitative when the operational fixation capacity of MnO2 for Fe2+ was exhausted. This corresponds to the event where adsorption and co-precipitation with FeCPs is intensive. Adsorption and co-precipitation are thus the fundamental mechanisms of decontamination in Fe0/H2O systems. Hybrid Fe0/MnO2 systems are potential candidates for the design of more sustainable Fe0 filters.
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Affiliation(s)
- Viet Cao
- Faculty of Natural Sciences, Hung Vuong University, Nguyen Tat Thanh Street, Viet Tri, Phu Tho, 35120, Vietnam
| | - Ghinwa Alyoussef
- Angewandte Geologie, Universität Göttingen, Goldschmidtstraße 3, 37077, Göttingen, Germany
| | - Nadège Gatcha-Bandjun
- Faculty of Science, Department of Chemistry, University of Maroua, BP 46, Maroua, Cameroon
| | - Willis Gwenzi
- Biosystems and Environmental Engineering Research Group, Department of Agricultural and Biosystems Engineering, University of Zimbabwe, P.O. Box MP167, Mt. Pleasant, Harare, Zimbabwe
| | - Chicgoua Noubactep
- Angewandte Geologie, Universität Göttingen, Goldschmidtstraße 3, 37077, Göttingen, Germany. .,Centre for Modern Indian Studies (CeMIS), Universität Göttingen, Waldweg 26, 37073, Göttingen, Germany. .,Department of Water and Environmental Science and Engineering, Nelson Mandela African Institution of Science and Technology, P.O. Box 447, Arusha, Tanzania.
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9
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Charbonnet JA, Duan Y, van Genuchten CM, Sedlak DL. Regenerated Manganese-Oxide Coated Sands: The Role of Mineral Phase in Organic Contaminant Reactivity. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2021; 55:5282-5290. [PMID: 33750102 DOI: 10.1021/acs.est.0c05745] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/12/2023]
Abstract
Manganese oxide-coated sand can oxidize electron-rich organic contaminants, but after extended exposure to contaminated water its reactivity decreases. To assess the potential for regenerating geomedia, we measured the ability of passivated manganese-oxide coated sand to oxidize bisphenol A after treatment with oxidants, acid, or methanol. Among the regenerants studied, KMnO4, HOCl, HOBr, and pH 2 or 3 HCl solutions raised the average oxidation state of the Mn, but only HOCl and HOBr restored the reactivity of passivated geomedia to levels comparable to those of the virgin manganese-oxide coated sand. Treatment with HCl restored about one third of the reactivity of the material, likely due to dissolution of reduced Mn. Mn K-edge X-ray absorption spectroscopy data indicated that the reactive manganese oxide phases present in virgin geomedia and geomedia regenerated with HOCl or HOBr had nanocrystalline cryptomelane-like structures and diminished Mn(III) abundance relative to the passivated geomedia. KMnO4-regenerated geomedia also had less Mn(III), but it exhibited less reactivity with bisphenol A because regeneration produced a structure with characteristics of δ-MnO2. The results imply that manganese oxide reactivity depends on both oxidation state and crystal structure; the most effective chemical regenerants oxidize Mn(III) to Mn(IV) oxides exhibiting nanocrystalline, cryptomelane-like forms.
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Affiliation(s)
- Joseph A Charbonnet
- National Science Foundation Engineering Research Center for Reinventing the Nation's Urban Water Infrastructure (ReNUWIt) and Department of Civil & Environmental Engineering, University of California, Berkeley, California United States
| | - Yanghua Duan
- National Science Foundation Engineering Research Center for Reinventing the Nation's Urban Water Infrastructure (ReNUWIt) and Department of Civil & Environmental Engineering, University of California, Berkeley, California United States
| | - Case M van Genuchten
- Geochemistry Department of the Geological Survey of Denmark and Greenland (GEUS), Copenhagen, Denmark
| | - David L Sedlak
- National Science Foundation Engineering Research Center for Reinventing the Nation's Urban Water Infrastructure (ReNUWIt) and Department of Civil & Environmental Engineering, University of California, Berkeley, California United States
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The Suitability of Methylene Blue Discoloration (MB Method) to Investigate the Fe0/MnO2 System. Processes (Basel) 2021. [DOI: 10.3390/pr9030548] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023] Open
Abstract
The typical time-dependent decrease of the iron corrosion rate is often difficult to consider while designing Fe0-based remediation systems. One of the most promising approaches is the amendment with manganese dioxide (Fe0/MnO2 system). The resulting system is a very complex one where characterization is challenging. The present communication uses methylene blue discoloration (MB method) to characterize the Fe0/MnO2 system. Shaken batch experiments (75 rpm) for 7 days were used. The initial MB concentration was 10 mg L−1 with the following mass loading: [MnO2] = 2.3 g L−1, [sand] = 45 g L−1, and 0 < [Fe0] (g L−1) ≤ 45. The following systems where investigated: Fe0, MnO2, sand, Fe0/MnO2, Fe0/sand, and Fe0/MnO2/sand. Results demonstrated that MB discoloration is influenced by the diffusive transport of MB from the solution to the aggregates at the bottom of the test-tubes. Results confirm the complexity of the Fe0/MnO2/sand system, while establishing that both MnO2 and sand improve the efficiency of Fe0/H2O systems in the long-term. The mechanisms of water decontamination by amending Fe0-based systems with MnO2 is demonstrated by the MB method.
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11
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Krupińska I. Removing Iron and Organic Substances from Water over the Course of Its Treatment with the Application of Average and Highly Alkaline Polyaluminium Chlorides. Molecules 2021; 26:molecules26051367. [PMID: 33806418 PMCID: PMC7961557 DOI: 10.3390/molecules26051367] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2021] [Revised: 02/22/2021] [Accepted: 02/25/2021] [Indexed: 11/29/2022] Open
Abstract
In topic-related literature pertaining to the treatment of water, there is a lack of information on the influence of iron ions in highly basic polyaluminum chlorides on the efficiency of purifying water with increased contents of organic substance. The aim of this work was to determine the changes in the content of organic substances as well as iron compounds in water intended for human consumption following unit treatment processes with particular attention paid to the coagulation process. As coagulants, polyaluminium chloride PAXXL10 with an alkalinity of 70%, as well as polyaluminium chloride PAXXL1911 with an alkalinity of 85% the composition of which also contained iron, were tested. The analysis of the obtained results showed that iron compounds and organic substances were removed to the greatest extent by the coagulation process, which also had a significant influence on the final efficiency of water treatment. The effectiveness of water treatment was determined by the type of tested polyaluminum chloride, which influenced the formation of iron-organic complexes. The reason behind the formation of colored iron-organic complexes during coagulation using PAXXL1911 coagulant was the high pH (approx. 8), at which the functional groups of organic substances, due to their dissociation, are more reactive in relation to iron, and possibly the fact of introducing additional iron ions along with the coagulant.
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Affiliation(s)
- Izabela Krupińska
- Faculty of Civil Engineering, Architecture and Environmental Engineering, Institute of Environmental Engineering, University of Zielona Góra, 15 Prof. Z. Szafrana St, 65-516 Zielona Góra, Poland
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12
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The Kinetics of Manganese Sorption on Ukrainian Tuff and Basalt—Order and Diffusion Models Analysis. MINERALS 2020. [DOI: 10.3390/min10121065] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
The study aimed to determine the nature of the kinetics of the manganese sorption process on Ukrainian tuff and basalt at different temperatures characteristic of the natural water environment. The scope of the research included manganese sorption kinetic test on natural mineral sorbents at temperatures of 10, 17.5 and 25 °C in slightly acidic conditions. Sorption (pseudo-first order, pseudo-second order and Elovich models) and diffusion kinetic models (liquid film diffusion and intraparticle diffusion) were used in the analysis of test results. The manganese sorption process on both tuff and basalt proceeded quickly. The dynamic equilibrium state of manganese sorption settled after 35 and 45 min on tuff and basalt respectively. Although the process took place in a slightly acidic environment and below pHPZC of the sorbents, possible electrostatic repulsion did not inhibit the removal of Mn. The Mn sorption on both materials followed the PSO kinetics model. Based on the diffusion kinetic models, it was determined that Mn sorption process on both materials was influenced by diffusion through the boundary layer and intraparticle diffusion. The differences in removal efficiency and rate of Mn sorption in the temperature range of 10–25 °C were not found.
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13
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The Impact of Microstructure of Filtration Materials on Its Auto-Activation for Manganese Removal from Groundwater. MINERALS 2020. [DOI: 10.3390/min10060502] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
The study investigates the impact of pore structure parameters of three chemically non-active filtration materials on the auto-activation time and the height of the filtration zone for manganese removal from groundwater. At a technical scale, the activation is a long process which may require a period of up to three months. The process can be shortened by the use of porous filtration materials. In this study, three filtration materials (silica sand, chalcedonite sand, GAC—granulated activated carbon) were investigated using subcritical nitrogen adsorption and mercury injection capillary pressure measurements. These methods provide a comprehensive evaluation of pore structure parameters, including specific surface area (SSA), micro- and mesopore volumes, and an extended range of pore size distribution (PSD). The studied materials provided a wide range of micro- and mesopore volumes as well as SSA. In order to investigate the auto-activation time of filtration material—the time required to achieve the requested quality of the filtrate—and the height of the filtration zone, a pilot experiment was conducted for 1950 h. The pilot installation consisted of three-meters-high (10 cm diameter) filtration columns filled with the tested filtration materials. The results indicate that the internal pore structure and the investigated auto-activation parameters are correlated. Both auto-activation time and the size of the filtration zone were influenced by the mesopore volume and the associated SSA of the tested materials. The micropore volume was less effective in improving the autoactivation parameters. The research results indicated the importance of pore structure characteristics which should be considered prior to time-consuming pilot and technological tests.
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