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Yang B, Zhou P, Tian L, Graham N, Li G, Su Z, Yu W. The nanoscale explanation of metal cations differences in enhancing the Fe(III) coagulation performance. WATER RESEARCH 2025; 280:123524. [PMID: 40147297 DOI: 10.1016/j.watres.2025.123524] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/24/2025] [Revised: 03/17/2025] [Accepted: 03/19/2025] [Indexed: 03/29/2025]
Abstract
Coagulation is a widely applied and important process for water treatment, and the development of improved coagulation reagents continues to be a practical objective. However, mechanisms guiding the development of composite coagulants remain insufficiently understood. In addressing this deficiency, this study has investigated the enhancement of conventional Fe(III) coagulation by composite coagulants that incorporate an additional metal salt (Me: Ca²⁺, Al³⁺, Ti⁴⁺, Zr⁴⁺), focusing on the mechanistic roles that Me constituents play in Fe-based coagulation. The effectiveness of composite coagulants was assessed through floc size and the removal of organics and phosphates. Results demonstrated that Me constituents enhance coagulation performances to varying extents, with Al³⁺ and Zr⁴⁺ showing the most significant improvements. FT-ICR MS analysis at the molecular scale reveals that additional Me facilitates the removal of humic acid, hydrophobic macromolecules, and highly aromatic organics containing polycarboxyl and secondary carbon structures. EXAFS results indicate that co-hydrolysis of Fe³⁺ with Me disrupts the formation of conventional ferrihydrite at the nanoscale of flocs and promotes the development of Fe-phosphate clusters. Me effectively reduces the corner- and edge-sharing coordination between FeO₆ octahedra within clusters, resulting in a more dispersed arrangement of FeO₆ polymers with available binding sites for the PO4 tetrahedron. The shortened Fe-P bond indicates that Me promotes a more compact link between FeO₆ octahedra and PO₄ tetrahedra. By revealing how cations in composite coagulants change the nanoscale structure of Fe flocs to affect macroscopic coagulation, this study enhances the understanding of metal ion interactions during co-hydrolysis and co-precipitation in natural systems.
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Affiliation(s)
- Bingqian Yang
- State Key Laboratory of Environmental Aquatic Chemistry, Key Laboratory of Drinking Water Science and Technology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, PR China; College of Resources and Environment, University of Chinese Academy of Sciences (UCAS), Beijing 100049, PR China
| | - Peng Zhou
- State Key Laboratory of Environmental Aquatic Chemistry, Key Laboratory of Drinking Water Science and Technology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, PR China; College of Resources and Environment, University of Chinese Academy of Sciences (UCAS), Beijing 100049, PR China
| | - Long Tian
- State Key Laboratory of Environmental Aquatic Chemistry, Key Laboratory of Drinking Water Science and Technology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, PR China; College of Resources and Environment, University of Chinese Academy of Sciences (UCAS), Beijing 100049, PR China
| | - Nigel Graham
- Department of Civil and Environmental Engineering, Imperial College London, South Kensington Campus, London SW7 2AZ, United Kingdom
| | - Guibai Li
- State Key Laboratory of Urban Water Resource and Environment (SKLUWRE), Harbin Institute of Technology, 73 Huanghe Road, Nangang District, Harbin 150090, PR China
| | - Zhaoyang Su
- State Key Laboratory of Environmental Aquatic Chemistry, Key Laboratory of Drinking Water Science and Technology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, PR China.
| | - Wenzheng Yu
- State Key Laboratory of Environmental Aquatic Chemistry, Key Laboratory of Drinking Water Science and Technology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, PR China.
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2
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Kong Y, Dai S, Chen Q, Nie Y, Ma J. Enhanced oxidation and in-situ coagulation Fe(Ⅱ)/peroxymonosulfate-Mn(Ⅶ) process for carbamazepine removal: Multiple promoting effects of Mn and direct/indirect regulation of Cl- on active substances transformation. JOURNAL OF HAZARDOUS MATERIALS 2025; 485:136933. [PMID: 39708606 DOI: 10.1016/j.jhazmat.2024.136933] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/03/2024] [Revised: 12/04/2024] [Accepted: 12/17/2024] [Indexed: 12/23/2024]
Abstract
Slow transformation efficiency of Fe(III)/Fe(II) limits the generation of radicals in peroxymonosulfate (PMS)-based advanced oxidation processes (AOPs), and these radicals was easy to be interfered by the presence of water constituents. In addition, in-situ coagulation during this oxidation process was neglected. This study proposed Fe(II)/PMS-Mn(VII) in the presence of chlorides ions (FPMC) process to reveal multiple promoting effects of Mn on redox cycle of Fe(III)/Fe(II) and different reactive mechanisms of Cl- on types of radicals generation pathways, and the in-situ coagulation enhanced mechanisms was investigated. Results showed that the dual functionality of oxidation and in-situ coagulation in FPMC process was significantly enhanced that carbamazepine (CBZ) could be efficiently and quickly removed. The reduction product Mn(III) of Mn(VII) could promote the redox cycle of Mn(II)/Mn(III) and Mn(III)/Mn(IV) that facilitated Fe(III)/Fe(II), sustaining the reactivity of the system. Cl- could significantly promote the cycling of Mn(Ⅲ)/Mn(Ⅳ) that indirectly affected the cycle of Fe(III)/Fe(II).
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Affiliation(s)
- Yanli Kong
- School of Civil Engineering and Architecture, Anhui University of Technology, Maanshan, Anhui 243002, China; Engineering Research Center of Biomembrane Water Purification and Utilization Technology, Ministry of Education, Maanshan, Anhui 243002, China
| | - Siyu Dai
- School of Civil Engineering and Architecture, Anhui University of Technology, Maanshan, Anhui 243002, China
| | - Qingwu Chen
- School of Civil Engineering and Architecture, Anhui University of Technology, Maanshan, Anhui 243002, China
| | - Yong Nie
- School of Civil Engineering and Architecture, Anhui University of Technology, Maanshan, Anhui 243002, China; Engineering Research Center of Biomembrane Water Purification and Utilization Technology, Ministry of Education, Maanshan, Anhui 243002, China
| | - Jiangya Ma
- School of Civil Engineering and Architecture, Anhui University of Technology, Maanshan, Anhui 243002, China; Engineering Research Center of Biomembrane Water Purification and Utilization Technology, Ministry of Education, Maanshan, Anhui 243002, China.
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3
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Yang C, Li Q, Chen X, Li M, He X, Li G, Shao Y, Wu J. Effects of the combined use of lanthanum carbonate and activated carbon capping materials on phosphorus and dissolved organic matter in lake sediments. ENVIRONMENTAL RESEARCH 2025; 264:120291. [PMID: 39505129 DOI: 10.1016/j.envres.2024.120291] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/05/2024] [Revised: 10/28/2024] [Accepted: 11/03/2024] [Indexed: 11/08/2024]
Abstract
Lanthanum carbonate (LC) represents a novel material for the immobilization of internal phosphorus (P) in sediments. Activated carbon (AC) is a traditional adsorbent that has been employed in the remediation of sediments on a wide scale. The objective of this study is to examine the mechanisms and effects of the combined use of LC and AC capping materials on the immobilization of P and dissolved organic matter (DOM) in sediments, through a 90-day incubation experiment. The results of isotherm experiments showed that the adsorption mechanism of P on LC and AC was mainly chemisorption. The XPS analyses showed the adsorption mechanism of P on LC was mainly ligand exchange and inner-sphere complexation; while the adsorption mechanism of P on AC was mainly ligand exchange and electrostatic adsorption. The results demonstrated that the concentrations of soluble reactive phosphorus (SRP) and DOM in the 0 to -100 mm sediment layer were reduced by 69.79% and 33.93%, respectively, in comparison to the control group with the LC + AC group. Moreover, the HCl-P and Res-P (stable P) in the 0-5 cm sediment layer were increased by 50.07% and 21.04%, respectively, in the LC + AC group. This indicates that the combined application of LC and AC has the potential to reduce the risk of P release. Furthermore, the formation of Fe(III)/Mn(IV) oxyhydroxides by LC + AC treatment resulted in an increased adsorption of SRP and DOM. Moreover, the effect of LC + AC capping on microbial community was smaller than that of LC/AC capping alone. The findings of this study indicated that the combined use of LC and AC represents a novel approach to the effective treatment of internal P and DOM in eutrophic lake sediments.
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Affiliation(s)
- Chenjun Yang
- National Key Laboratory of Water Disaster Prevention, Hohai University, Nanjing, 210098, China
| | - Qi Li
- National Key Laboratory of Water Disaster Prevention, Hohai University, Nanjing, 210098, China.
| | - Xiang Chen
- Nanjing Institute of Environmental Sciences, Ministry of Ecology and Environment, Nanjing, 210042, China
| | - Minjuan Li
- National Key Laboratory of Water Disaster Prevention, Hohai University, Nanjing, 210098, China
| | - Xiangyu He
- National Key Laboratory of Water Disaster Prevention, Hohai University, Nanjing, 210098, China
| | - Gaoxiang Li
- National Key Laboratory of Water Disaster Prevention, Hohai University, Nanjing, 210098, China
| | - Yichun Shao
- National Key Laboratory of Water Disaster Prevention, Hohai University, Nanjing, 210098, China
| | - Jingwei Wu
- National Key Laboratory of Water Disaster Prevention, Hohai University, Nanjing, 210098, China
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Lv Y, Wang W, Yin H. Efficacy of P-sorbent material combined with aquatic plants in controlling nutrient release from urban lake sediment: Field investigation. ENVIRONMENTAL RESEARCH 2024; 263:120233. [PMID: 39455043 DOI: 10.1016/j.envres.2024.120233] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/11/2024] [Revised: 10/22/2024] [Accepted: 10/23/2024] [Indexed: 10/28/2024]
Abstract
The release of stored nutrients from sediments is thought to substantially affect water quality in urban lakes. To explore the efficiency of different in-situ remediation methods on controlling high internal urban lake sediments, 120 days of field-enclosure experiments were conducted to investigate the efficacy of P-sorbent materials combined with aquatic plants in controlling nutrient release from urban-lake sediments. The lanthanum-modified clay (LMC) effectively reduced sediment P release flux and could temporarily lead to a small increase in N concentration in the overlying water. In contrast, Vallisneria spiralis (V. spiralis) has a relatively weak effect on controlling nutrient release and can even cause an increase in P concentration. The combined restoration technique of V. spiralis + LMC can overcome the drawbacks of a single method, reduce the nutrient content in overlying water, and inhibit the sediment internal release. Relative to the control, the V. spiralis + LMC treatment reduced mobile P content by 52.5% and increased Ca-P content by 34.5%. The added lanthanum contained material can quickly bind the readily released P in sediment and porewater, transforming it into intert P over time. Submerged macrophytes can absorb active P in water and sediments and transport oxygen to sediments promoting denitrification and N removal. The combined restoration technique synergistically combines the high P sorption affinity of LMC and the substrate improvement effect of V. spiralis, thus realizing the long-term control of endogenous release in urban lakes. This approach holds great promise for restoring urban lakes with high endogenous nutrient loading.
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Affiliation(s)
- Yaobin Lv
- State Key Laboratory of Lake Science and Environment, Nanjing Institute of Geography and Limnology, Chinese Academy of Sciences, Nanjing, 210008, China; University of Chinese Academy of Sciences, 19 Yuquan Road, Beijing, 100049, China; University of Chinese Academy of Sciences, Nanjing, Nanjing, 211135, China
| | - Weizhen Wang
- State Key Laboratory of Lake Science and Environment, Nanjing Institute of Geography and Limnology, Chinese Academy of Sciences, Nanjing, 210008, China
| | - Hongbin Yin
- State Key Laboratory of Lake Science and Environment, Nanjing Institute of Geography and Limnology, Chinese Academy of Sciences, Nanjing, 210008, China; University of Chinese Academy of Sciences, Nanjing, Nanjing, 211135, China.
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5
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Fang J, Li Y, Su M, Cao T, Sun X, Ai Y, Qin J, Yu J, Yang M. Mitigating harmful cyanobacterial blooms in drinking water reservoirs through in-situ sediment resuspension. WATER RESEARCH 2024; 267:122509. [PMID: 39353347 DOI: 10.1016/j.watres.2024.122509] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/08/2024] [Revised: 07/30/2024] [Accepted: 09/22/2024] [Indexed: 10/04/2024]
Abstract
Mitigating harmful cyanobacterial blooms is a global challenge, particularly crucial for safeguarding source water. Given the limitations of current technologies for application in drinking water reservoirs, we propose an innovative strategy based on in-situ sediment resuspension (SR). This method's effectiveness in cyanobacterial control and its potential impacts on water quality were assessed through laboratory culture experiments and further validated via field applications in five drinking water reservoirs. The results revealed that SR could significantly mitigate cyanobacterial growth, evidenced by the treated sets (removal rate: 3.82×106 cells L-1d-1) compared to the control set (growth rate: 2.22×107 cells L-1d-1) according to the laboratory experiments. The underlying mechanisms identified included underwater light reduction (2.38× increase in extinction coefficient) and flocculation and entrainment of cells by resuspended particles (30 % reduction per operation). Additional contributions were noted in the reduction of bioavailable phosphate and remediation of anaerobic sediment characterized by increased redox potential. This facilitated the oxidation of iron, which in turn promoted the co-precipitation of phosphate (removal rate: 46 μg L-1d-1) and inhibited its release from the sediment. The SR operation, devoid of importing extra substances, represents a safe and economical technology for controlling harmful cyanobacteria in drinking water reservoirs.
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Affiliation(s)
- Jiao Fang
- State Key Laboratory of Environmental Aquatic Chemistry, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, P.O. Box 2871, Beijing 100085, PR China; School of Environment and Spatial Informatics, China University of Mining and Technology, P.O. Box 2871, Xuzhou 221116, PR China
| | - Yande Li
- Management Station of Shuangxikou Reservoir, Reservoir Management Service Center of Yuyao City, P.O. Box 2871, Ningbo, Zhejiang Province 315423, PR China
| | - Ming Su
- State Key Laboratory of Environmental Aquatic Chemistry, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, P.O. Box 2871, Beijing 100085, PR China; University of Chinese Academy of Sciences, Beijing 100049, PR China.
| | - Tengxin Cao
- State Key Laboratory of Environmental Aquatic Chemistry, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, P.O. Box 2871, Beijing 100085, PR China; University of Chinese Academy of Sciences, Beijing 100049, PR China
| | - Xufeng Sun
- Zhejiang Weicheng Huanbao Co. Ltd., Yunxiu North Road 1200, Huzhou 313200, PR China
| | - Yufan Ai
- State Key Laboratory of Environmental Aquatic Chemistry, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, P.O. Box 2871, Beijing 100085, PR China; University of Chinese Academy of Sciences, Beijing 100049, PR China
| | - Jinyi Qin
- School of Civil Engineering, Chang'an University, P.O. Box 2871, Xi'an 710054, PR China
| | - Jianwei Yu
- State Key Laboratory of Environmental Aquatic Chemistry, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, P.O. Box 2871, Beijing 100085, PR China; University of Chinese Academy of Sciences, Beijing 100049, PR China
| | - Min Yang
- State Key Laboratory of Environmental Aquatic Chemistry, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, P.O. Box 2871, Beijing 100085, PR China; University of Chinese Academy of Sciences, Beijing 100049, PR China.
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6
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Liu L, Zhao L, Jin S, Zou W, Wang H, Xie Y, Hou C, Zhai Y, Luo P. Treatment of sludge hydrothermal carbonization wastewater by ferrous/sodium percarbonate system: Effect of wastewater composition and role of coagulation and oxidation. WATER RESEARCH 2024; 267:122531. [PMID: 39366323 DOI: 10.1016/j.watres.2024.122531] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/03/2024] [Revised: 08/15/2024] [Accepted: 09/25/2024] [Indexed: 10/06/2024]
Abstract
It is crucial to explore the effect of complex wastewater compositions on the ferrous/sodium percarbonate (Fe(Ⅱ)/SPC) system and the role of oxidation-coagulation in designing water treatment processes. This study employed redundancy analysis to investigate the effects of wastewater constituents on oxidation and coagulation. Raman analysis, X-ray Photoelectron Spectroscopy, and Fourier Transform Ion Cyclotron Resonance Mass Spectrometry were used to determine the roles of oxidation and coagulation in the system. The results showed that sulfates and phosphates formed amorphous complexes with iron species via coprecipitation, thereby promoting coagulation to remove organics. Some heavy metals can also be removed by coagulation. The co-activation of SPC by pre-existing transition metals and the added Fe(Ⅱ) facilitated the oxidative removal of organics, while chloride and arsenic were the main inhibitory inorganic substances in the system. Aromatic compounds mainly promoted coagulation, polysaccharides promoted oxidation, humic acid promoted oxidation and coagulation, and C=C/C=O inhibited the Fe(Ⅱ)/SPC system. The oxidation process removed graphitic structures and unsaturated organic matter in the region of (O/C, H/C) = (0.2-0.4, 0.9-2.0) through free radicals and generated amorphous carbon structures and saturated organic matter in the region of (O/C, H/C) = (0.3-0.7, 1.2-1.9). The coagulation process removed aromatic organics with 2-5 rings and unsaturated organics in the region of (O/C, H/C) = (0.2-0.6, 0.7-1.6) with oxygen-containing organics. The combined effects of coagulation and oxidation enhanced the removal efficiency of organic carbon by approximately 40%. This study facilitates the optimization of hydrothermal carbonization wastewater treatment and advanced oxidation processes.
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Affiliation(s)
- Liming Liu
- College of Environmental Science and Engineering, Hunan University, Changsha, 410082, P.R. China; Key Laboratory of Environmental Biology and Pollution Control, Hunan University, Ministry of Education, Changsha, 410082, P.R. China; Department of Civil and Earth Resources Engineering, Kyoto University, Kyoto, 612-8236, Japan
| | - Luna Zhao
- College of Environmental Science and Engineering, Hunan University, Changsha, 410082, P.R. China; Key Laboratory of Environmental Biology and Pollution Control, Hunan University, Ministry of Education, Changsha, 410082, P.R. China
| | - Shiyun Jin
- College of Environmental Science and Engineering, Hunan University, Changsha, 410082, P.R. China; Key Laboratory of Environmental Biology and Pollution Control, Hunan University, Ministry of Education, Changsha, 410082, P.R. China
| | - Wei Zou
- College of Environmental Science and Engineering, Hunan University, Changsha, 410082, P.R. China; Key Laboratory of Environmental Biology and Pollution Control, Hunan University, Ministry of Education, Changsha, 410082, P.R. China
| | - Hongxia Wang
- College of Environmental Science and Engineering, Hunan University, Changsha, 410082, P.R. China; Key Laboratory of Environmental Biology and Pollution Control, Hunan University, Ministry of Education, Changsha, 410082, P.R. China
| | - Yu Xie
- College of Environmental Science and Engineering, Hunan University, Changsha, 410082, P.R. China; Key Laboratory of Environmental Biology and Pollution Control, Hunan University, Ministry of Education, Changsha, 410082, P.R. China
| | - Changlan Hou
- College of Environmental Science and Engineering, Hunan University, Changsha, 410082, P.R. China; Key Laboratory of Environmental Biology and Pollution Control, Hunan University, Ministry of Education, Changsha, 410082, P.R. China
| | - Yunbo Zhai
- College of Environmental Science and Engineering, Hunan University, Changsha, 410082, P.R. China; Key Laboratory of Environmental Biology and Pollution Control, Hunan University, Ministry of Education, Changsha, 410082, P.R. China.
| | - Pingping Luo
- School of Water and Environment, Chang'an University, Xi'an 710054, P.R. China
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7
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Zhao R, Li B, Chen S, Zhang B, Chen J, Sun J, Ma X. Intertwined role of mechanism identification by DFT-XAFS and engineering considerations in the evolution of P adsorbents. THE SCIENCE OF THE TOTAL ENVIRONMENT 2024; 946:174159. [PMID: 38909797 DOI: 10.1016/j.scitotenv.2024.174159] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/18/2024] [Revised: 06/18/2024] [Accepted: 06/18/2024] [Indexed: 06/25/2024]
Abstract
Adsorption method exhibits promising potential in effectively removal of phosphate from wastewater, yet it faces tremendous challenges in practical application. Limited comprehension of adsorption mechanisms and the lack of evaluation method for scaling up application are the two main obstacles. To fully realize the practical application of P adsorbents, we reviewed advanced tools, including density functional theory (DFT) and/or X-ray absorption fine structure (XAFS) to elucidate mechanisms, underscored the significance of thermodynamics and kinetics in engineering design, and proposed strategies for regenerating and reusing P adsorbents. Specifically, we delved into the utilization of DFT and XAFS to gain insights into adsorption mechanisms, focusing on active site verification and molecular interaction configurations. Additionally, we explored precise calculation methods for adsorption thermodynamics and adsorption kinetics, encompassing thermodynamic equilibrium constants, reactor selection, and the regeneration, recovery, and disposal of P adsorbents. Our comprehensive review aims to serve as a guiding light in advancing the development of highly efficient P adsorbents for engineering applications.
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Affiliation(s)
- Ruining Zhao
- School of Energy and Environmental Engineering, Hebei University of Technology, Tianjin 300401, China
| | - Benhang Li
- School of Energy and Environmental Engineering, Hebei University of Technology, Tianjin 300401, China
| | - Siyuan Chen
- School of Energy and Environmental Engineering, Hebei University of Technology, Tianjin 300401, China
| | - Boxuan Zhang
- School of Energy and Environmental Engineering, Hebei University of Technology, Tianjin 300401, China
| | - Jiale Chen
- School of Energy and Environmental Engineering, Hebei University of Technology, Tianjin 300401, China
| | - Jiahe Sun
- School of Energy and Environmental Engineering, Hebei University of Technology, Tianjin 300401, China
| | - Xiaodong Ma
- School of Energy and Environmental Engineering, Hebei University of Technology, Tianjin 300401, China.
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Liu M, Liu X, Graham NJD, Yu W. Uncovering the neglected role of anions in trivalent cation-based coagulation processes. WATER RESEARCH 2024; 254:121352. [PMID: 38401286 DOI: 10.1016/j.watres.2024.121352] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/09/2023] [Revised: 01/08/2024] [Accepted: 02/20/2024] [Indexed: 02/26/2024]
Abstract
Coagulation efficiency is heavily contingent upon a profound comprehension of the underlying mechanisms, facilitated by the evolution of coagulation theory. However, the role of anions, prevalent components in raw and wastewaters, has been relatively overlooked in this context. To address this gap, this study has investigated the impact of three common anions (i.e., chloride, sulfate, and phosphate) on Al-based coagulation. The results have shown that the influence of anions on coagulation depends predominantly on their ability to compete with hydroxyl groups throughout the entire coagulation process, encompassing hydrolysis, aggregation, and the growth of large flocs. Moreover, this competition is subject to the dual influence of both anion concentration and hydroxyl concentration (i.e., pH). The results have revealed the intricate interplay between anions and coagulants, their impact on floc structure, and their importance in optimizing coagulation efficiency and ensuring the production of high-quality water.
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Affiliation(s)
- Mengjie Liu
- Key Laboratory of Drinking Water Science and Technology, Research Centre for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China
| | - Xun Liu
- School of Chemistry and Chemical Engineering, Beijing Institute of Technology, Beijing 100081, China
| | - Nigel J D Graham
- Department of Civil and Environmental Engineering, Imperial College London, South Kensington Campus, London SW7 2AZ, United Kingdom
| | - Wenzheng Yu
- Key Laboratory of Drinking Water Science and Technology, Research Centre for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China.
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9
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Chen X, Liu L, Wang Y, Zhou L, Xiao J, Yan W, Li M, Li Q, He X, Zhang L, You X, Zhu D, Yan J, Wang B, Hang X. The combined effects of lanthanum-modified bentonite and Vallisneria spiralis on phosphorus, dissolved organic matter, and heavy metal(loid)s. THE SCIENCE OF THE TOTAL ENVIRONMENT 2024; 917:170502. [PMID: 38301791 DOI: 10.1016/j.scitotenv.2024.170502] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/07/2023] [Revised: 01/10/2024] [Accepted: 01/25/2024] [Indexed: 02/03/2024]
Abstract
The use of lanthanum-modified bentonite (LMB) combined with Vallisneria spiralis (V∙s) (LMB + V∙s) is a common method for controlling internal phosphorus (P) release from sediments. However, the behaviors of iron (Fe) and manganese (Mn) under LMB + V∙s treatments, as well as the associated coupling effect on P, dissolved organic matter (DOM), and heavy metal(loid)s (HMs), require further investigations. Therefore, we used in this study a microelectrode system and high-resolution dialysis technology (HR-Peeper) to study the combined effects of LMB and V∙s on P, DOM, and HMs through a 66-day incubation experiment. The LMB + V∙s treatment increased the sediment DO concentration, promoting in-situ formations of Fe (III)/Mn (IV) oxyhydroxides, which, in turn, adsorbed P, soluble tungsten (W), DOM, and HMs. The increase in the concentrations of HCl-P, amorphous and poorly crystalline (oxyhydr) oxides-bound W, and oxidizable HMs forms demonstrated the capacity of the LMB + V∙s treatment to transform mobile P, W, and other HMs forms into more stable forms. The significant positive correlations between SRP, soluble W, UV254, and soluble Fe (II)/Mn, and the increased concentrations of the oxidizable HMs forms suggested the crucial role of the Fe/Mn redox in controlling the release of SRP, DOM, and HMs from sediments. The LMB + V∙s treatment resulted in SRP, W, and DOM removal rates of 74.49, 78.58, and 54.78 %, which were higher than those observed in the control group (without LMB and V∙s applications). On the other hand, the single and combined uses of LMB and V·s influenced the relative abundances of the sediment microbial communities without exhibiting effects on microbial diversity. This study demonstrated the key role of combined LMB and V∙s applications in controlling the release of P, W, DOM, and HMs in eutrophic lakes.
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Affiliation(s)
- Xiang Chen
- Nanjing Institute of Environmental Sciences, Ministry of Ecology and Environment, Nanjing 210042, China; College of Hydrology and Water Resources, Hohai University, Nanjing 210098, China
| | - Ling Liu
- College of Hydrology and Water Resources, Hohai University, Nanjing 210098, China
| | - Yan Wang
- Nanjing Institute of Environmental Sciences, Ministry of Ecology and Environment, Nanjing 210042, China
| | - Li Zhou
- Nanjing Institute of Environmental Sciences, Ministry of Ecology and Environment, Nanjing 210042, China
| | - Jing Xiao
- Nanjing Institute of Environmental Sciences, Ministry of Ecology and Environment, Nanjing 210042, China
| | - Wenming Yan
- The National Key Laboratory of Water Disaster Prevention, Hohai University, Nanjing 210098, China
| | - Minjuan Li
- The National Key Laboratory of Water Disaster Prevention, Hohai University, Nanjing 210098, China
| | - Qi Li
- College of Hydrology and Water Resources, Hohai University, Nanjing 210098, China
| | - Xiangyu He
- College of Hydrology and Water Resources, Hohai University, Nanjing 210098, China; The National Key Laboratory of Water Disaster Prevention, Hohai University, Nanjing 210098, China
| | - Lan Zhang
- Nanjing Institute of Environmental Sciences, Ministry of Ecology and Environment, Nanjing 210042, China
| | - Xiaohui You
- Nanjing Institute of Environmental Sciences, Ministry of Ecology and Environment, Nanjing 210042, China
| | - Dongdong Zhu
- Nanjing Institute of Environmental Sciences, Ministry of Ecology and Environment, Nanjing 210042, China
| | - Jiabao Yan
- Nanjing Institute of Environmental Sciences, Ministry of Ecology and Environment, Nanjing 210042, China
| | - Bin Wang
- Zhongyifeng Construction Group Co., Ltd., Suzhou 215131, China
| | - Xiaoshuai Hang
- Nanjing Institute of Environmental Sciences, Ministry of Ecology and Environment, Nanjing 210042, China.
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Wang X, Li Y, Wen X, Liu L, Zhang L, Long M. Cooperation of ferrous ions and hydrated ferric oxide for advanced phosphate removal over a wide pH range: Mechanism and kinetics. WATER RESEARCH 2024; 249:120969. [PMID: 38086202 DOI: 10.1016/j.watres.2023.120969] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/24/2023] [Revised: 11/16/2023] [Accepted: 12/01/2023] [Indexed: 01/03/2024]
Abstract
Excessive phosphate loading leads to eutrophication problems in rivers or lakes and causes serious environmental and economic damages, urging new technologies to reduce effluent phosphate at ultra-low levels. As a promising candidate, adsorption over metal oxides is restricted by the released hydroxide anions (OH-) through ligand exchange, which elevates pH and suppresses further adsorption. In this contribution, we found ferrous ions (Fe2+) significantly enhance phosphate removal over hydrated ferric oxide (HFO) in a wide pH range via a cooperation of adsorption and precipitation, and clarified the synergistic mechanism by a series of characterizations and the modified models of adsorption isotherms and pseudo second-order kinetics. The combination of Fe2+and HFO removed up to 51.7 mg/g of phosphate at pH 4.0, with 43.6 and 8.1 mg/g attributing to adsorption and precipitation, respectively. In comparison to HFO alone, HFO/Fe2+ system achieved 2.2-fold increase in phosphate removal, 1.9-fold increase in phosphate adsorption capacity, and 3.4-fold increase in phosphate removal rate. The enhancement is understood by that hydroxide anions released from ligand exchange over HFO are neutralized by protons produced from the oxidative precipitation of ferrous ions. The HFO/Fe2+ combining system is promising to realize advanced removal of low concentration phosphate containing wastewater, and these findings bring new insights for the development of novel phosphate removal technologies through a rational design of a combination process.
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Affiliation(s)
- Xiaohui Wang
- School of Environmental Science and Engineering, Key Laboratory of Thin Film and Microfabrication Technology (Ministry of Education), Shanghai Jiao Tong University, Shanghai 200240, China
| | - Yang Li
- School of Environmental Science and Engineering, Key Laboratory of Thin Film and Microfabrication Technology (Ministry of Education), Shanghai Jiao Tong University, Shanghai 200240, China
| | - Xue Wen
- School of Environmental Science and Engineering, Key Laboratory of Thin Film and Microfabrication Technology (Ministry of Education), Shanghai Jiao Tong University, Shanghai 200240, China
| | - Liyan Liu
- Student Innovation Center, Shanghai Jiao Tong University, Shanghai 200240, China
| | - Lizhi Zhang
- School of Environmental Science and Engineering, Key Laboratory of Thin Film and Microfabrication Technology (Ministry of Education), Shanghai Jiao Tong University, Shanghai 200240, China
| | - Mingce Long
- School of Environmental Science and Engineering, Key Laboratory of Thin Film and Microfabrication Technology (Ministry of Education), Shanghai Jiao Tong University, Shanghai 200240, China.
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