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Yang X, Wang S, Pi K, Ge H, Zhang S, Gerson AR. Coagulation as an effective method for cyanobacterial bloom control: A review. WATER ENVIRONMENT RESEARCH : A RESEARCH PUBLICATION OF THE WATER ENVIRONMENT FEDERATION 2024; 96:e11002. [PMID: 38403998 DOI: 10.1002/wer.11002] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/15/2023] [Revised: 01/28/2024] [Accepted: 01/30/2024] [Indexed: 02/27/2024]
Abstract
Eutrophication, the over-enrichment with nutrients, for example, nitrogen and phosphorus, of ponds, reservoirs and lakes, is an urgent water quality issue. The most notorious symptom of eutrophication is a massive proliferation of cyanobacteria, which cause aquatic organism death, impair ecosystem and harm human health. The method considered to be most effective to counteract eutrophication is to reduce external nutrient inputs. However, merely controlling external nutrient load is insufficient to mitigate eutrophication. Consequently, a rapid diminishing of cyanobacterial blooms is relied on in-lake intervention, which may encompass a great variety of different approaches. Coagulation/flocculation is the most used and important water purification unit. Since cyanobacterial cells generally carry negative charges, coagulants are added to water to neutralize the negative charges on the surface of cyanobacteria, causing them to destabilize and precipitate. Most of cyanobacteria and their metabolites can be removed simultaneously. However, when cyanobacterial density is high, sticky secretions distribute outside cells because of the small size of cyanobacteria. The sticky secretions are easily to form complex colloids with coagulants, making it difficult for cyanobacteria to destabilize and resulting in unsatisfactory treatment effects of coagulation on cyanobacteria. Therefore, various coagulants and coagulation methods were developed. In this paper, the focus is on the coagulation of cyanobacteria as a promising tool to manage eutrophication. Basic principles, applications, pros and cons of chemical, physical and biological coagulation are reviewed. In addition, the application of coagulation in water treatment is discussed. It is the aim of this review article to provide a significant reference for large-scale governance of cyanobacterial blooms. PRACTITIONER POINTS: Flocculation was a promising tool for controlling cyanobacteria blooms. Basic principles of four kinds of flocculation methods were elucidated. Flocculant was important in the flocculation process.
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Affiliation(s)
- Xian Yang
- Innovation Demonstration Base of Ecological Environment Geotechnical and Ecological Restoration of Rivers and Lakes, School of Civil and Environmental Engineering, Hubei University of Technology, Wuhan, China
| | - Shulian Wang
- Innovation Demonstration Base of Ecological Environment Geotechnical and Ecological Restoration of Rivers and Lakes, School of Civil and Environmental Engineering, Hubei University of Technology, Wuhan, China
- Cooperative Innovation Center of Industrial Fermentation (Ministry of Education & Hubei Province), Hubei University of Technology, Wuhan, China
| | - Kewu Pi
- Innovation Demonstration Base of Ecological Environment Geotechnical and Ecological Restoration of Rivers and Lakes, School of Civil and Environmental Engineering, Hubei University of Technology, Wuhan, China
- National Engineering Research Center of Advanced Technology and Equipment for Water Environment Pollution Monitoring, Hubei University of Technology, Wuhan, China
| | - Hongmei Ge
- Innovation Demonstration Base of Ecological Environment Geotechnical and Ecological Restoration of Rivers and Lakes, School of Civil and Environmental Engineering, Hubei University of Technology, Wuhan, China
| | - Shuo Zhang
- Innovation Demonstration Base of Ecological Environment Geotechnical and Ecological Restoration of Rivers and Lakes, School of Civil and Environmental Engineering, Hubei University of Technology, Wuhan, China
| | - Andrea R Gerson
- Blue Minerals Consultancy, Wattle Grove, Tasmania, Australia
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Du J, Tian C, Xiao J, Liu Y, Zhang F, Gao X, Xing B, Zhao Y. Co-fermentation of titanium-flocculated-sludge with food waste towards simultaneous water purification and resource recovery. WATER RESEARCH 2024; 251:121110. [PMID: 38198972 DOI: 10.1016/j.watres.2024.121110] [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: 10/06/2023] [Revised: 01/04/2024] [Accepted: 01/05/2024] [Indexed: 01/12/2024]
Abstract
Recovery of resources from domestic sewage and food waste has always been an international-thorny problem. Titanium-based flocculation can achieve high-efficient destabilization, quick concentration and separation of organic matter from sewage to sludge. This study proposed co-fermentation of the titanium-flocculated sludge (Ti-loaded sludge) and food waste towards resource recovery by converting organic matter to value-added volatile fatty acids (VFAs) and inorganic matter to struvite and TiO2 nanoparticles. When Ti-loaded sludge and food waste were co-fermented at a mass ratio of 3:1, the VFAs yield reached 3725.2 mg-COD/L (VFAs/SCOD 91.0%), which was more than 4 times higher than the case of the sludge alone. The 48-day semicontinuous co-fermentation demonstrated stable long-term operation, yielding VFAs at 2529.0 mg-COD/L (VFAs/SCOD 89.8%) and achieving a high CODVFAs/NNH4 of 58.9. Food waste provided sufficient organic substrate, enriching plenty of acid-producing fermentation bacteria (such as Prevotella 7 about 21.0% and Bacteroides about 9.4%). Moreover, metagenomic sequencing analysis evidenced the significant increase of the relative gene abundance corresponding to enzymes in pathways, such as extracellular hydrolysis, substrates metabolism, and VFAs biosynthesis. After fermentation, the precious element P (≥ 99.0%) and extra-added element Ti (≥99.0%) retained in fermented residues, without releasing to VFAs supernatant, which facilitated the direct re-use of VFAs as resource. Through simple and commonly used calcination and acid leaching methodologies, 80.9% of element P and 82.1% of element Ti could be successfully recovered as struvite and TiO2 nanoparticles, respectively. This research provides a strategy for the co-utilization of domestic sludge and food waste, which can realize both reduction of sludge and recovery of resources.
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Affiliation(s)
- Jinming Du
- School of Water Conservancy and Environment, University of Jinan, 250022, Jinan, Shandong, China
| | - Chang Tian
- School of Environmental Science & Engineering, Qilu University of Technology (Shandong Academy of Sciences), 3501 Daxue Road, 250353, Jinan, Shandong, China
| | - Jianan Xiao
- Shandong Huankeyuan Environmental Testing Co., Ltd, 250013, Shandong, China
| | - Yuyu Liu
- School of Water Conservancy and Environment, University of Jinan, 250022, Jinan, Shandong, China
| | - Fenfen Zhang
- School of Water Conservancy and Environment, University of Jinan, 250022, Jinan, Shandong, China
| | - Xiaomei Gao
- School of Water Conservancy and Environment, University of Jinan, 250022, Jinan, Shandong, China
| | - Baoshan Xing
- Shaanxi Provincial Key Lab of Environmental Engineering, Xi'an University of Architecture and Technology, No. 13 Yanta Road, Xi'an, 710055, China
| | - Yanxia Zhao
- School of Water Conservancy and Environment, University of Jinan, 250022, Jinan, Shandong, China.
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Liu B, Gao Y, Yue Q, Guo K, Gao B. Microcosmic mechanism analysis of the combined pollution of aged polystyrene with humic acid and its efficient removal by a composite coagulant. JOURNAL OF HAZARDOUS MATERIALS 2023; 459:132272. [PMID: 37573824 DOI: 10.1016/j.jhazmat.2023.132272] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/15/2023] [Revised: 07/24/2023] [Accepted: 08/09/2023] [Indexed: 08/15/2023]
Abstract
The composite pollutants formed by aged polystyrene (APS) and natural organic matter are complex and harmful, which lead to the deterioration of water quality. In this work, the interaction mechanism between humic acid (HA) and APS was discussed by investigating the changes in their functional groups. Besides, a novel polyaluminum-titanium chloride composite coagulant (PATC) was prepared, and its binding behaviors with HA@APS under different pH conditions were analyzed from a microscopic perspective. It was found that at pH 4, π-π conjugation was the dominant interaction between HA and APS. And the main removal mechanism of HA@APS by PATC was surface complexation. With the increase of pH, π-π conjugation, n-π electron donor-acceptor interaction (EDA), and hydrogen bonding gradually dominated the interaction between APS and HA. At pH 7, PATC hydrolyzed to form various polynuclear Al-Ti species, which could meet the demand for different binding sites of HA@APS. Under alkaline conditions, HB and n-π EDA in HA@APS were weakened, while π-π conjugation held a dominant position again. At this time, the main coagulation mechanism of PATC changed from charge neutralization to sweeping action, accompanied by hydrogen bonding. ENVIRONMENTAL IMPLICATION: Microplastics (MPs) have attracted the public's attention due to their potential toxicity to humans. The combined pollution of aged microplastics and humic acid (HA) will bring great harm to aquatic environment. The development of novel composite coagulants is hopeful to efficiently remove MPs and their combined pollutants. Elucidating the interactions between HA and aged MPs is helpful to understand the transformation and fate of MPs in actual environments, and to reveal the removal mechanism of composite pollutants by coagulation. The findings presented here will provide theoretical guidance for addressing the challenges of coagulation technology in treating new pollutants in practice.
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Affiliation(s)
- Beibei Liu
- Shandong Key Laboratory of Water Pollution Control and Resource Reuse, School of Environmental Science and Engineering, Shandong University, Qingdao 26600, PR China
| | - Yue Gao
- Shandong Key Laboratory of Water Pollution Control and Resource Reuse, School of Environmental Science and Engineering, Shandong University, Qingdao 26600, PR China
| | - Qinyan Yue
- Shandong Key Laboratory of Water Pollution Control and Resource Reuse, School of Environmental Science and Engineering, Shandong University, Qingdao 26600, PR China
| | - Kangying Guo
- Shandong Key Laboratory of Water Pollution Control and Resource Reuse, School of Environmental Science and Engineering, Shandong University, Qingdao 26600, PR China.
| | - Baoyu Gao
- Shandong Key Laboratory of Water Pollution Control and Resource Reuse, School of Environmental Science and Engineering, Shandong University, Qingdao 26600, PR China.
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Li Y, Wang Y, Jin J, Tian Z, Yang W, Graham NJD, Yang Z. Enhanced removal of trace pesticides and alleviation of membrane fouling using hydrophobic-modified inorganic-organic hybrid flocculants in the flocculation-sedimentation-ultrafiltration process for surface water treatment. WATER RESEARCH 2023; 229:119447. [PMID: 36476382 DOI: 10.1016/j.watres.2022.119447] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/23/2022] [Revised: 11/29/2022] [Accepted: 11/30/2022] [Indexed: 06/17/2023]
Abstract
Pesticide concentrations in surface water occasionally exceed regulated values due to seasonal events (rainy season in high intensity agricultural areas) or intermittent discharges (leakage, spillage, or other emergency events). The need to remove pesticide compounds in these situations poses a challenge for drinking water treatment plants (DWTPs). In this work, the performance of dosing hydrophobic-modified inorganic-organic hybrid flocculants (HOC-M; lower acute toxicity than corresponding metal salt coagulants; acceptable economic costs when M=Al or Fe; prepared in large-scale quantities), for the removal of four different pesticides (each initial concentration: 0.25 μg/L) from Yangtze River water, and in mitigating membrane fouling, by an integrated flocculation-sedimentation-ultrafiltration (FSUF) process, was evaluated over a period of 40 days; the FSUF is well-established in many DWTPs. The mechanisms underlying the treatment were unveiled by employing a combination of instrumental characterizations, chemical computations, material flow analyses, and statistical analyses. Efficient pesticide removal (80.3%∼94.3%) and membrane fouling reduction (26.6%∼37.3% and 28.3%∼57.6% for reversible and irreversible membrane resistance, respectively) in the FSUF process were achieved by dosing HOC-M, whereas conventional inorganic coagulants were substantially inferior for pesticide removal (< 50%) and displayed more severe fouling development. Hydrophobic association between the pesticides and the hydrophobic organic chain of HOC-M played a predominant role in the improvement in pesticide removal; coexisting particulate/colloid inorganic minerals and natural organic matter with HOC-M adsorbed on the surface, acting as floc building materials, provided sites for the indirect combination of pesticides into flocs. The observed fouling alleviation from dosing HOC-M was ascribed to both the pre-removal of fouling-causing materials in the flocculation-sedimentation prior to UF, and a stable hydrophilization modification effect of residual HOC-M in the UF unit. The latter effect resulted from a hydrophobic association between the PVDF substrate of the membranes and the hydrophobic organic chains of the HOC-M, causing the hydrophilic ends of the HOC-M to be exposed away from the membrane surface, thereby inhibiting foulant accumulation. This work has not only demonstrated the superior performance of dosing HOC-M in the FSUF process for trace pesticide removal in DWTPs, but also clarified the underlying mechanisms.
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Affiliation(s)
- Yunyun Li
- School of Chemistry and Materials Science, Jiangsu Provincial Key Laboratory of Material Cycling and Pollution Control, Nanjing Normal University, Nanjing 210023, China
| | - Yadong Wang
- School of Chemistry and Materials Science, Jiangsu Provincial Key Laboratory of Material Cycling and Pollution Control, Nanjing Normal University, Nanjing 210023, China
| | - Jin Jin
- School of Chemistry and Materials Science, Jiangsu Provincial Key Laboratory of Material Cycling and Pollution Control, Nanjing Normal University, Nanjing 210023, China
| | - Ziqi Tian
- Ningbo Institute of Materials Technology and Engineering, Chinese Academy of Sciences, Ningbo 315000, China
| | - Weiben Yang
- School of Chemistry and Materials Science, Jiangsu Provincial Key Laboratory of Material Cycling and Pollution Control, Nanjing Normal University, Nanjing 210023, China
| | - Nigel J D Graham
- Department of Civil and Environmental Engineering, Imperial College London, London SW7 2AZ, United Kingdom
| | - Zhen Yang
- School of Chemistry and Materials Science, Jiangsu Provincial Key Laboratory of Material Cycling and Pollution Control, Nanjing Normal University, Nanjing 210023, China.
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Xu X, Guo J, Yang R, Gao Y, Xue Y, Wang L, Zhang L, Zhang Q, Peng M, Liu X. Construction of titanium-aluminum xerogel composite coagulant for removal of tetracycline in water: synergy effects and improvement mechanisms insight. ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH INTERNATIONAL 2023; 30:18285-18295. [PMID: 36208375 DOI: 10.1007/s11356-022-23448-0] [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: 06/07/2022] [Accepted: 09/30/2022] [Indexed: 06/16/2023]
Abstract
Titanium xerogel coagulant (TXC) is a new type of coagulant that has attracted much attention in recent years. However, the tetracycline removal performance of TXC was not satisfactory because low isoelectric point (pHiep) inhibited the electrical neutralization efficiency of TXC in an alkaline environment. To overcome this shortcoming, a composite xerogel coagulant (titanium-aluminum xerogel composite coagulant) was prepared. The removal of tetracycline and turbidity was used as evaluation indexes. It was proved that the combination of aluminum (III) and titanium (IV) enhanced the resistance of TXC to pH. The synthesized titanium-aluminum xerogel composite coagulant (TXAC) has an excellent removal ability of tetracycline in a wide pH range (pH = 5-10). At pH 8.8, the dosage required to remove 80% tetracycline from water decreased from 93 (TXC) to 35 mg/L (TXAC). The reason for this improvement could be attributed to (i) aluminum (III) enhanced the electric neutralization of TXC to negatively charged pollutants in an alkaline environment; (ii) the complexing ability of organic matter and aluminum (III) was enhanced. This work provides a feasible scheme for the pretreatment of tetracycline in water to meet the pretreatment requirements of special water.
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Affiliation(s)
- Xia Xu
- School of Environmental and Safety Engineering, Changzhou University, Changzhou, 213164, China
| | - Jun Guo
- School of Environmental and Safety Engineering, Changzhou University, Changzhou, 213164, China
| | - Ruoying Yang
- School of Environmental and Safety Engineering, Changzhou University, Changzhou, 213164, China
| | - Yu Gao
- School of Environmental and Safety Engineering, Changzhou University, Changzhou, 213164, China
| | - Yingang Xue
- School of Environmental and Safety Engineering, Changzhou University, Changzhou, 213164, China.
| | - Liping Wang
- School of Environmental and Safety Engineering, Changzhou University, Changzhou, 213164, China
| | - Ling Zhang
- School of Environmental and Safety Engineering, Changzhou University, Changzhou, 213164, China
| | - Qiuya Zhang
- School of Environmental and Safety Engineering, Changzhou University, Changzhou, 213164, China
| | - Mingguo Peng
- School of Environmental and Safety Engineering, Changzhou University, Changzhou, 213164, China
| | - Xuefeng Liu
- School of Environmental and Safety Engineering, Changzhou University, Changzhou, 213164, China
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Guo K, Wang Z, Pan J, Liu B, Wang Y, Yue Q, Gao Y, Gao B. Highly efficient Al-Ti gel as a coagulant for surface water treatment: Insights into the hydrolysate transformation and coagulation mechanism. WATER RESEARCH 2022; 221:118826. [PMID: 35834971 DOI: 10.1016/j.watres.2022.118826] [Citation(s) in RCA: 12] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/18/2022] [Revised: 06/21/2022] [Accepted: 07/04/2022] [Indexed: 06/15/2023]
Abstract
In view of the insufficient coagulation efficiency of traditional inorganic coagulants, a series of Al-Ti gels with different Ti/triethanolamine (TEA), Ti/H2O, and Ti/Al molar ratios were prepared by sol-gel process in this study. Fourier transform infrared (FTIR) spectra of the Al-Ti gels preliminarily confirmed the interaction between Al and Ti by detecting the appearance of the Al-O-Ti bond. The peak shift of the chemical bonds in X-ray photoelectron spectra (XPS) and the transformation of the hydrolysate species in the Al-Ti gels were analyzed to further explore the interaction mechanism between Al and Ti. It was found that moderate TEA could inhibit the hydrolysis of Ti precursors by taking up the coordination sites of H2O to form a CO-Ti bond. Density functional theory (DFT) calculation results showed that Ti could be incorporated into the framework of aluminum hydrolysates to form an Al-O-Ti bond, and [Al2Ti2(OH)x(TEA)y(H2O)8-x-y]14-x was the most possible copolymerization hydrolysate. Based on the above research results, the most efficient Al-Ti gel was selected and applied to the actual lake water treatment. The highest UV254 removal efficiency with the addition of Al-Ti gel was > 60%, nearly 25% higher than that of Ti gel. The hydrolysates of Al-Ti gel, such as TiO(OH)2(am), Al(OH)3(am), and [Al2Ti2(OH)x(TEA)y(H2O)8-x-y]14-x, could remove organic matters through the incorporation of charge neutralization, adsorption, complexation, and sweeping effects. These results provide a new idea for studying the interaction mechanism between Al and Ti in composite coagulants, and have theoretical guiding significance to actual water treatment.
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Affiliation(s)
- Kangying Guo
- Shandong Key Laboratory of Water Pollution Control and Resource Reuse, School of Environmental Science and Engineering, Shandong University, Qingdao 266000, China
| | - Zhining Wang
- Shandong Key Laboratory of Water Pollution Control and Resource Reuse, School of Environmental Science and Engineering, Shandong University, Qingdao 266000, China
| | - Jingwen Pan
- Shandong Key Laboratory of Water Pollution Control and Resource Reuse, School of Environmental Science and Engineering, Shandong University, Qingdao 266000, China
| | - Beibei Liu
- Shandong Key Laboratory of Water Pollution Control and Resource Reuse, School of Environmental Science and Engineering, Shandong University, Qingdao 266000, China
| | - Yan Wang
- Shandong Key Laboratory of Water Pollution Control and Resource Reuse, School of Environmental Science and Engineering, Shandong University, Qingdao 266000, China
| | - Qinyan Yue
- Shandong Key Laboratory of Water Pollution Control and Resource Reuse, School of Environmental Science and Engineering, Shandong University, Qingdao 266000, China
| | - Yue Gao
- Shandong Key Laboratory of Water Pollution Control and Resource Reuse, School of Environmental Science and Engineering, Shandong University, Qingdao 266000, China.
| | - Baoyu Gao
- Shandong Key Laboratory of Water Pollution Control and Resource Reuse, School of Environmental Science and Engineering, Shandong University, Qingdao 266000, China.
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Liu B, Gao Y, Pan J, Feng Q, Yue Q, Guo K, Gao B. Coagulation behavior of polyaluminum-titanium chloride composite coagulant with humic acid: A mechanism analysis. WATER RESEARCH 2022; 220:118633. [PMID: 35613484 DOI: 10.1016/j.watres.2022.118633] [Citation(s) in RCA: 20] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/22/2022] [Revised: 05/07/2022] [Accepted: 05/16/2022] [Indexed: 06/15/2023]
Abstract
The hydrolysate species of metal-based coagulants and the binding sites of humic acid (HA) are highly dependent on the pH conditions. Exploring the binding sites and modes between coagulant hydrolysates and HA molecules is critical to understanding the coagulation mechanism. In this paper, the binding behavior between HA molecules and the hydrolysates of a polyaluminum-titanium chloride composite coagulant (PATC) was investigated under different pH conditions by semi-quantitative FTIR and XPS. It was found that oligomeric and mesopolymeric hydrolysates were the dominant species under acid conditions, which could complex with the hydroxyl and carboxyl groups of HA by forming COAl/Ti coordinate bonds. However, large amounts of H+ could compete with Al3+ and weaken the removal efficiency of HA. With the increase of pH, the hydrolysis process of the PATC and the deprotonation of HA were simultaneously underway. Under weakly acid conditions, the complexation of the aluminum hydrolysates with carboxyl groups was improved due to the gradually diminishing competition of H+ and the enhanced charge neutralization of the further polymerized hydrolysates. Consequently, the maximum UV254 removal by adding PATC was observed at pH 6. Under alkaline conditions, the sweeping effect of amorphous hydroxide dominated the HA removals, which was accompanied by the surface complexation of Al/Ti nuclear with carboxyl groups as well as the hydrogen bonds between hydroxyl and hydroxide. This study provides a new clue for the interaction mechanisms between the hydrolysates of composite coagulants and the dominant functional groups of HA at various pH conditions.
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Affiliation(s)
- Beibei Liu
- Shandong Key Laboratory of Water Pollution Control and Resource Reuse, School of Environmental Science and Engineering, Shandong University, Qingdao, 26600, PR China
| | - Yue Gao
- Shandong Key Laboratory of Water Pollution Control and Resource Reuse, School of Environmental Science and Engineering, Shandong University, Qingdao, 26600, PR China
| | - Jingwen Pan
- Shandong Key Laboratory of Water Pollution Control and Resource Reuse, School of Environmental Science and Engineering, Shandong University, Qingdao, 26600, PR China
| | - Qiyun Feng
- Shandong Key Laboratory of Water Pollution Control and Resource Reuse, School of Environmental Science and Engineering, Shandong University, Qingdao, 26600, PR China
| | - Qinyan Yue
- Shandong Key Laboratory of Water Pollution Control and Resource Reuse, School of Environmental Science and Engineering, Shandong University, Qingdao, 26600, PR China
| | - Kangying Guo
- Shandong Key Laboratory of Water Pollution Control and Resource Reuse, School of Environmental Science and Engineering, Shandong University, Qingdao, 26600, PR China.
| | - Baoyu Gao
- Shandong Key Laboratory of Water Pollution Control and Resource Reuse, School of Environmental Science and Engineering, Shandong University, Qingdao, 26600, PR China.
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Yue Y, An G, Lin L, Demissie H, Yang X, Jiao R, Wang D. Design and coagulation mechanism of a new functional composite coagulant in removing humic acid. Sep Purif Technol 2022. [DOI: 10.1016/j.seppur.2022.121016] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/23/2023]
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Wu B, Li J, Gan Y, Zhihao H, Li H, Zhang S. Titanium xerogel as a potential alternative for polymeric ferric sulfate in coagulation removal of antimony from reverse osmosis concentrate. Sep Purif Technol 2022. [DOI: 10.1016/j.seppur.2022.120863] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
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10
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Du Z, Gong Z, Qi W, Li E, Shen J, Li J, Zhao H. Coagulation performance and floc characteristics of poly-ferric-titanium-silicate-chloride in coking wastewater treatment. Colloids Surf A Physicochem Eng Asp 2022. [DOI: 10.1016/j.colsurfa.2022.128413] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
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Wang Z, Li Y, Hu M, Lei T, Tian Z, Yang W, Yang Z, Graham NJD. Influence of DOM characteristics on the flocculation removal of trace pharmaceuticals in surface water by the successive dosing of alum and moderately hydrophobic chitosan. WATER RESEARCH 2022; 213:118163. [PMID: 35151090 DOI: 10.1016/j.watres.2022.118163] [Citation(s) in RCA: 18] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/19/2021] [Revised: 01/11/2022] [Accepted: 02/03/2022] [Indexed: 06/14/2023]
Abstract
Hydrophobically-modified chitosan (HC) has emerged as a promising flocculant for trace pharmaceutical removal from surface water. However, the variation in the characteristics of dissolved organic matter (DOM) in different water sources influences the efficacy of HC in removing pharmaceutical compounds. In this work, the flocculation performance of sequentially dosing alum and HC (alum+HC) for the treatment of five water types (three synthetic waters, and samples of two real waters collected from the Yangtze River and the Thames River), having different DOM and five representative pharmaceuticals (initial concentration: 100 ng/L), was assessed by bench-scale jar tests. The DOM characteristics were correlated quantitatively with the removal efficiencies (REs) of the pharmaceuticals. Density functional theory computations were performed to illuminate the interfacial interactions in the flocculation. Alum+HC exhibited a remarkably higher RE of all five pharmaceuticals (maximum RE: 73%-95%) from all waters compared to a conventional coagulant or flocculant (alum or polyacrylamide, respectively). In contrast to using HC alone, alum+HC also achieved a higher RE of pharmaceuticals with nearly half the HC dosage, thereby enhancing the cost-effectiveness of the alum+HC dosing system. Among the different key DOM characteristics, the surface charge and molecular weight of DOM had no evident correlation with RE(pharmaceutical), but the hydrophobic/hydrophilic nature and functional group composition of organic carbon of DOM were strongly correlated: Strongly hydrophobic fractions, with C-C & C=C functional groups (binding pharmaceuticals via hydrophobic association), were beneficial, while hydrophilic fractions with C-OH groups were less effective, for pharmaceutical removal. This work showed the enhanced performance of the alum+HC dosing combination in the removal of different pharmaceutical compounds from different waters, and filled the knowledge gap regarding the performance of hydrophobically-modified flocculants in the treatment of different surface water sources.
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Affiliation(s)
- Zhangzheng Wang
- School of Chemistry and Materials Science, Jiangsu Provincial Key Laboratory of Material Cycling and Pollution Control, Nanjing Normal University, Nanjing 210046, China
| | - Yunyun Li
- School of Chemistry and Materials Science, Jiangsu Provincial Key Laboratory of Material Cycling and Pollution Control, Nanjing Normal University, Nanjing 210046, China
| | - Min Hu
- School of Chemistry and Materials Science, Jiangsu Provincial Key Laboratory of Material Cycling and Pollution Control, Nanjing Normal University, Nanjing 210046, China
| | - Tao Lei
- School of Chemistry and Materials Science, Jiangsu Provincial Key Laboratory of Material Cycling and Pollution Control, Nanjing Normal University, Nanjing 210046, China
| | - Ziqi Tian
- Ningbo Institute of Materials Technology and Engineering, Chinese Academy of Sciences, Ningbo 315000, China
| | - Weiben Yang
- School of Chemistry and Materials Science, Jiangsu Provincial Key Laboratory of Material Cycling and Pollution Control, Nanjing Normal University, Nanjing 210046, China
| | - Zhen Yang
- School of Chemistry and Materials Science, Jiangsu Provincial Key Laboratory of Material Cycling and Pollution Control, Nanjing Normal University, Nanjing 210046, China.
| | - Nigel J D Graham
- Department of Civil and Environmental Engineering, Imperial College London, SW7 2AZ, UK
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12
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Coagulation performance of Al/Fe based covalently bonded composite coagulants for algae removal. Sep Purif Technol 2022. [DOI: 10.1016/j.seppur.2021.120401] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/23/2023]
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13
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Liu B, Gao B, Guo K, Pan J, Yue Q. The interactions between Al (III) and Ti (IV) in the composite coagulant polyaluminum-titanium chloride. Sep Purif Technol 2022. [DOI: 10.1016/j.seppur.2021.120148] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
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14
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15
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Xu M, Luo Y, Wang X, Zhou L. Coagulation-ultrafiltration efficiency of polymeric Al-, Fe-, and Ti- coagulant with or without polyacrylamide composition. Sep Purif Technol 2022. [DOI: 10.1016/j.seppur.2021.119957] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
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16
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Gan Y, Zhang L, Zhang S. The suitability of titanium salts in coagulation removal of micropollutants and in alleviation of membrane fouling. WATER RESEARCH 2021; 205:117692. [PMID: 34600229 DOI: 10.1016/j.watres.2021.117692] [Citation(s) in RCA: 19] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/15/2021] [Revised: 09/01/2021] [Accepted: 09/19/2021] [Indexed: 06/13/2023]
Abstract
Coagulation is a conventional method in water treatment. In recent decades, with the rapid development of membrane filtration, the use of coagulation is facing some new challenges. How to minimize the membrane fouling became a leading-edge topic in the study of coagulation. Here, the performances of three types of titanium coagulants were evaluated in terms of both the coagulation removal of toxic micropollutants and the alleviation of membrane fouling. Three oxysalts and two antibiotics were taken as representatives of inorganic and organic micropollutants. As compared with titanium tetrachloride (TiCl4) and polytitanium chloride (PTC), titanium xerogel (TXC) with a higher polymerization degree showed much better performances in direct coagulation removal of oxysalts and antibiotics and in pre-coagulation for mitigating membrane fouling in both coagulation-sedimentation-ultrafiltration (CSUF) and in-line coagulation-ultrafiltration (CUF) processes. In the CSUF system, the membrane permeate flux with TXC pre-coagulation (89.5%) was much higher than those of TiCl4 (56.1%) and PTC (57.4%). After a 5 day continuous operation, the transmembrane pressure in the CUF system with TXC coagulation was increased only to 4.9 kPa, while those of PTC and TiCl4 were 12.2 and 18.5 kPa, respectively. The results here demonstrate that TXC is a promising coagulant for pollutant removal and membrane fouling alleviation, due to the following merits: better floc properties, weaker pH-dependence, and higher resistance to coordination with organic pollutants. The observation shed new lights on the fabrication and application of coagulants in a wide variety of scenarios.
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Affiliation(s)
- Yonghai Gan
- State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, 163 Xianlin Avenue, Nanjing 210023, China
| | - Li Zhang
- State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, 163 Xianlin Avenue, Nanjing 210023, China
| | - Shujuan Zhang
- State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, 163 Xianlin Avenue, Nanjing 210023, China.
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17
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Wang K, Ran T, Yu P, Chen L, Zhao J, Ahmad A, Ramzan N, Xu X, Xu Y, Shi Y. Evaluation of renewable pH-responsive starch-based flocculant on treating and recycling of highly saline textile effluents. ENVIRONMENTAL RESEARCH 2021; 201:111489. [PMID: 34166665 DOI: 10.1016/j.envres.2021.111489] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/01/2021] [Revised: 06/03/2021] [Accepted: 06/03/2021] [Indexed: 06/13/2023]
Abstract
Herein, we report a novel renewable pH-responsive starch-based flocculant (CIAT-ST) via etherifying 2-chloro-4,6-isopropylamino-[1,3,5]-triazine (CIAT) onto the starch backbones for decontamination and reuse of highly saline effluents. The obtained CIAT-ST shows a unique pH-sensibility and reversibility in response to a subtle pH change due to a pH-controllable surface charge density of polymer chains. The level of residual CIAT-ST in the solution can be facilely monitored by using UV-vis detection. The dye flocculation performance of CIAT-ST was evaluated by using a batch experiment. The results exhibited that the dye removal was highly dependent on the solution pH (optimal pH was 2), the flocculation equilibrium can be achieved within 5 min, and the maximum flocculation capacity of CIAT-ST for K-2BP and KN-B5 were calculated to be 2452.6 ± 23.9 and 792.7 ± 14.1 mg/g, respectively. The multiple flocculation mechanisms, including charge neutralization, bridging and charge patching, may participate in the flocculation process. Adjustment in pH-mediated hydrophilicity-hydrophobicity switch of flocculant facilitates readily recovery and then sequentially reused three times while retaining satisfying flocculation efficiency. A significant contribution was also confirmed that the highly saline effluents after flocculation and sedimentation were reused in three successive dyeing processes without sacrificing fabric quality (ΔE* < 1) due to relatively low polymer residuals, and the efficiency of salt reuse for consecutive regeneration processes could be achieved above 85%. The present work could provide alternative thoughts for the reutilization of spent flocculant and clarified saline wastewater, which is also an efficient and sustainable strategy for textile wastewater management.
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Affiliation(s)
- Kaixiang Wang
- Key Laboratory for Green Processing of Chemical Engineering of Xinjiang Bingtuan, School of Chemistry and Chemical Engineering, Shihezi University, Shihezi, 832003, China
| | - Tingmin Ran
- Key Laboratory for Green Processing of Chemical Engineering of Xinjiang Bingtuan, School of Chemistry and Chemical Engineering, Shihezi University, Shihezi, 832003, China
| | - Pai Yu
- Key Laboratory for Green Processing of Chemical Engineering of Xinjiang Bingtuan, School of Chemistry and Chemical Engineering, Shihezi University, Shihezi, 832003, China
| | - Long Chen
- Key Laboratory for Green Processing of Chemical Engineering of Xinjiang Bingtuan, School of Chemistry and Chemical Engineering, Shihezi University, Shihezi, 832003, China
| | - Jigang Zhao
- Key Laboratory for Green Processing of Chemical Engineering of Xinjiang Bingtuan, School of Chemistry and Chemical Engineering, Shihezi University, Shihezi, 832003, China; International Joint Research Center for Green Energy Chemical Engineering, East China University of Science and Technology, Shanghai, 200237, China.
| | - Ayyaz Ahmad
- Department of Chemical Engineering, Muhammad Nawaz Sharif University of Engineering and Technology, Multan, 60000, Pakistan
| | - Naveed Ramzan
- Department of Chemical Engineering, University of Engineering and Technology, Lahore, 54890, Pakistan
| | - Xiaolin Xu
- Key Laboratory for Green Processing of Chemical Engineering of Xinjiang Bingtuan, School of Chemistry and Chemical Engineering, Shihezi University, Shihezi, 832003, China
| | - Yisheng Xu
- Key Laboratory for Green Processing of Chemical Engineering of Xinjiang Bingtuan, School of Chemistry and Chemical Engineering, Shihezi University, Shihezi, 832003, China; State Key Laboratory of Chemical Engineering, East China University of Science and Technology, Shanghai, 200237, China
| | - Yulin Shi
- Key Laboratory for Green Processing of Chemical Engineering of Xinjiang Bingtuan, School of Chemistry and Chemical Engineering, Shihezi University, Shihezi, 832003, China.
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18
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Hossain SM, Park H, Kang HJ, Mun JS, Tijing L, Rhee I, Kim JH, Jun YS, Shon HK. Synthesis and NO x removal performance of anatase S-TiO 2/g-CN heterojunction formed from dye wastewater sludge. CHEMOSPHERE 2021; 275:130020. [PMID: 33677268 DOI: 10.1016/j.chemosphere.2021.130020] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/19/2020] [Revised: 02/11/2021] [Accepted: 02/14/2021] [Indexed: 06/12/2023]
Abstract
In this study, sludges generated from Ti-based flocculation of dye wastewater were used to retrieve photoactive titania (S-TiO2). It was heterojunctioned with graphitic carbon nitride (g-CN) to augment photoactivity under UV/visible light irradiance. Later the as-prepared samples were utilized to remove nitrogen oxides (NOx) in the atmospheric condition through photocatalysis. Heterojunction between S-TiO2 and g-CN was prepared through facile calcination (@550 °C) of S-TiO2 and melamine mix. Advanced sample characterization was carried out and documented extensively. Successful heterojunction was confirmed from the assessment of morphological and optical attributes of the samples. Finally, the prepared samples' level of photoactivity was assessed through photooxidation of NOx under both UV and visible light irradiance. Enhanced photoactivity was observed in the prepared samples irrespective of the light types. After 1 h of UV/visible light-based photooxidation, the best sample STC4 was found to remove 15.18% and 9.16% of atmospheric NO, respectively. In STC4, the mixing ratio of S-TiO2, to melamine was maintained as 1:3. Moreover, the optical bandgap of STC4 was found as 2.65 eV, where for S-TiO2, it was 2.83 eV. Hence, the restrained rate of photogenerated charge recombination and tailored energy bandgap of the as-prepared samples were the primary factors for enhancing photoactivity.
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Affiliation(s)
- Sayed Mukit Hossain
- Faculty of Engineering and IT, University of Technology Sydney, P.O. Box 123, Broadway, NSW, 2007, Australia.
| | - Heeju Park
- School of Chemical Engineering, Chonnam National University, 77 Yongbong-ro, Buk-gu, Gwangju, 61186, Republic of Korea.
| | - Hui-Ju Kang
- Department of Advanced Chemicals & Engineering, Chonnam National University, 77 Yongbong-ro, Buk-gu, Gwangju, 61186, Republic of Korea.
| | - Jong Seok Mun
- School of Chemical Engineering, Chonnam National University, 77 Yongbong-ro, Buk-gu, Gwangju, 61186, Republic of Korea.
| | - Leonard Tijing
- Faculty of Engineering and IT, University of Technology Sydney, P.O. Box 123, Broadway, NSW, 2007, Australia.
| | - Inkyu Rhee
- Department of Civil Engineering, Chonnam National University, 77 Yongbong-ro, Buk-gu, Gwangju, 61186, Republic of Korea.
| | - Jong-Ho Kim
- School of Chemical Engineering, Chonnam National University, 77 Yongbong-ro, Buk-gu, Gwangju, 61186, Republic of Korea.
| | - Young-Si Jun
- Department of Advanced Chemicals & Engineering, Chonnam National University, 77 Yongbong-ro, Buk-gu, Gwangju, 61186, Republic of Korea.
| | - Ho Kyong Shon
- Faculty of Engineering and IT, University of Technology Sydney, P.O. Box 123, Broadway, NSW, 2007, Australia.
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19
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Moreno-Gil N, Badillo-Almaraz VE, Pérez-Hernández R, López-Reyes C, Issac-Olivé K. Comparison of the sorption behavior of 99Mo by Ti-, Si-, Ti-Si-xerogels and commercial sorbents. J Radioanal Nucl Chem 2021. [DOI: 10.1007/s10967-021-07663-6] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
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20
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Gao B, Chang Q, Yang H. Selective adsorption of ofloxacin and ciprofloxacin from a binary system using lignin-based adsorbents: Quantitative analysis, adsorption mechanisms, and structure-activity relationship. THE SCIENCE OF THE TOTAL ENVIRONMENT 2021; 765:144427. [PMID: 33418328 DOI: 10.1016/j.scitotenv.2020.144427] [Citation(s) in RCA: 17] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/14/2020] [Revised: 11/26/2020] [Accepted: 12/06/2020] [Indexed: 06/12/2023]
Abstract
A series of actinia-shaped lignin-based adsorbents (LNAEs) featuring lignin (LN) as the core and grafted poly(acrylic acid) (PAA) as the tentacle were designed and fabricated. Two fluoroquinolones (FQs) with similar molecular structures, ofloxacin (OFL) and ciprofloxacin (CIP), were used as targets to study the selective adsorption performance of LNAEs associated with the structural effects of the LN-based adsorbents in FQs binary aqueous system. The adsorption of the two FQs by LNAEs complied with the competitive Langmuir isothermal model, and showed selective removal of CIP over OFL due to the additional negative charge-assisted hydrogen bond (CAHB) formed between the carboxyl group of LNAEs and the secondary amino group of CIP, in addition to the effects of electrostatic attraction and normal hydrogen bonds, according to quantitative studies and density functional theory analysis. A binary nonlinear model based on phenomenological theory was applied to study the effects of PAA branched-chain length and distribution on the selective adsorption performance of the LN-based adsorbents. Accordingly, the branched-chain distribution played a more important role and higher distribution density of branched PAA could expose more adsorption sites on LNAEs' surface and improve the adsorptive selectivity. This study offers a well understanding of the structure-activity relationship of the surface grafting-modified adsorbents in binary pollutant systems and fundamental guidance for the exploitation and design of novel and efficient adsorbents.
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Affiliation(s)
- Boqiang Gao
- State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Nanjing 210023, PR China
| | - Qianqian Chang
- State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Nanjing 210023, PR China
| | - Hu Yang
- State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Nanjing 210023, PR China.
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21
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Xu M, Wang X, Zhou B, Zhou L. Pre-coagulation with cationic flocculant-composited titanium xerogel coagulant for alleviating subsequent ultrafiltration membrane fouling by algae-related pollutants. JOURNAL OF HAZARDOUS MATERIALS 2021; 407:124838. [PMID: 33352421 DOI: 10.1016/j.jhazmat.2020.124838] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/02/2020] [Revised: 12/04/2020] [Accepted: 12/10/2020] [Indexed: 06/12/2023]
Abstract
In-line coagulation-ultrafiltration is reliable to achieve the safe disposal of algae-laden water with alleviated membrane fouling. Poly(diallyl dimethyl ammonium chloride) (PDADMAC)-composited titanium xerogel (TXC) coagulant (abbreviated as P-T) was reported to possess better resistance to organic matter loads, and its mitigation effect on subsequent ultrafiltration efficiency towards algae-related pollutants was investigated in this study. Results showed that P-T coagulation effectively mitigated membrane fouling over pH 5.0-9.0, whereas TXC only worked better under acidic condition. Acidic environment facilitated algae and organic matter removal by pre-coagulation, thus greatly improving ultrafiltration efficiency. Under neutral and alkaline conditions, PDADMAC portion in P-T enhanced the coagulation removal towards algae and protein constituents, and simultaneously promoted the formation of flocs with unique porous structure, which jointly contributed to its high-efficient alleviation ability. Nevertheless, PDADMAC increased adhesion force between P-T coagulated flocs and membrane surface, thus slightly reducing the recovery rate of membrane flux at pH 5.0. Pearson correlation analyses implied that removing algae cells would prevent reversible fouling-induced flux decline, whereas eliminating organic matter could greatly promote ultrafiltration efficiency via mitigating irreversible fouling. Therefore, elevating removal efficiency of organic matters is still the major objective for ultrafiltration pretreatment technologies and the optimization direction towards TXC-based coagulants.
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Affiliation(s)
- Min Xu
- Department of Environmental Engineering, College of Resources and Environmental Sciences, Nanjing Agricultural University, Nanjing 210095, PR China
| | - Xiaomeng Wang
- Department of Environmental Engineering, College of Resources and Environmental Sciences, Nanjing Agricultural University, Nanjing 210095, PR China.
| | - Bo Zhou
- Department of Environmental Engineering, College of Resources and Environmental Sciences, Nanjing Agricultural University, Nanjing 210095, PR China
| | - Lixiang Zhou
- Department of Environmental Engineering, College of Resources and Environmental Sciences, Nanjing Agricultural University, Nanjing 210095, PR China
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22
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Wang X, Xu J, Xu M, Zhou B, Liang J, Zhou L. High-efficient removal of arsenite by coagulation with titanium xerogel coagulant. Sep Purif Technol 2021. [DOI: 10.1016/j.seppur.2020.118047] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
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23
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Gao B, Chang Q, Cai J, Xi Z, Li A, Yang H. Removal of fluoroquinolone antibiotics using actinia-shaped lignin-based adsorbents: Role of the length and distribution of branched-chains. JOURNAL OF HAZARDOUS MATERIALS 2021; 403:123603. [PMID: 32777749 DOI: 10.1016/j.jhazmat.2020.123603] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/08/2020] [Revised: 07/05/2020] [Accepted: 07/27/2020] [Indexed: 06/11/2023]
Abstract
A series of actinia-shaped lignin-based adsorbents (LNAEs) featuring lignin(LN) as the core and grafted poly(acrylic acid) (PAA) as the tentacle were designed and fabricated. LNAEs were applied to remove ofloxacin and ciprofloxacin from water, and their maximum adsorption capacities were 0.835 and 0.965 mmol/g at pH 6.0, respectively. However, their adsorption capacities were up to about 20 % and 31 % reductions in the present of NaCl and humic acid, respectively. Electrostatic attraction (EA) and hydrogen bonding (HB), including ordinary HB and negative charged auxiliary HB, were mainly involved in adsorption. Experimental and calculation results indicated HB contributes more than EA. The effects of two structural factors of LNAEs, namely, PAA branched-chain length(L) and distribution density(D), on the adsorption performance associated with HB and EA, were quantitatively discussed using a binary nonlinear model based on phenomenological theory. The fitting results were completely consistent with the experimental findings. D was more efficient than L in promoting HB and EA in adsorption due to the cooperative effects of adjacent branched-chains and enhanced activity of terminal groups. This study provides a better understanding of the structure-activity relationship of surface grafting-modified adsorbents and fundamental guidance for the exploitation and design of novel and efficient adsorbents.
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Affiliation(s)
- Boqiang Gao
- State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Nanjing, 210023, PR China
| | - Qianqian Chang
- State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Nanjing, 210023, PR China
| | - Jun Cai
- State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Nanjing, 210023, PR China
| | - Zhonghua Xi
- State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Nanjing, 210023, PR China
| | - Aimin Li
- State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Nanjing, 210023, PR China
| | - Hu Yang
- State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Nanjing, 210023, PR China.
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24
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Dong W, Yang L, Qian F, Lv Z, Wu C, Xiang T, Chen D. Sandwiched meshes with superwettability for oil/water separation and heavy metal ion absorption. ASIA-PAC J CHEM ENG 2020. [DOI: 10.1002/apj.2542] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Affiliation(s)
- Wei Dong
- School of Civil Engineering and Architecture Anhui University of Technology Ma'anshan Anhui China
- School of Metallurgical Engineering Anhui University of Technology Ma'anshan Anhui China
| | - Ling Yang
- College of Materials Science and Technology Nanjing University of Aeronautics and Astronautics Nanjing Jiangsu China
| | - Fuping Qian
- School of Civil Engineering and Architecture Anhui University of Technology Ma'anshan Anhui China
| | - Zhong Lv
- School of Civil Engineering and Architecture Anhui University of Technology Ma'anshan Anhui China
| | - Chunhua Wu
- School of Civil Engineering and Architecture Anhui University of Technology Ma'anshan Anhui China
| | - Tengfei Xiang
- School of Civil Engineering and Architecture Anhui University of Technology Ma'anshan Anhui China
- Institute of Green Building Materials Anhui University of Technology Ma'anshan Anhui China
| | - Depeng Chen
- School of Civil Engineering and Architecture Anhui University of Technology Ma'anshan Anhui China
- Institute of Green Building Materials Anhui University of Technology Ma'anshan Anhui China
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25
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Yang Z, Hou T, Ma J, Yuan B, Tian Z, Yang W, Graham NJD. Role of moderately hydrophobic chitosan flocculants in the removal of trace antibiotics from water and membrane fouling control. WATER RESEARCH 2020; 177:115775. [PMID: 32278991 DOI: 10.1016/j.watres.2020.115775] [Citation(s) in RCA: 42] [Impact Index Per Article: 10.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/27/2019] [Revised: 03/26/2020] [Accepted: 03/31/2020] [Indexed: 05/09/2023]
Abstract
In this paper we describe the preparation and testing of a new class of chitosan-based flocculants for the treatment of surface waters containing antibiotic compounds. Three forms of moderately hydrophobic chitosan flocculants (MHCs) were prepared by chemically grafting hydrophobic branches with different lengths onto hydrophilic chitosan and these were evaluated by jar tests and a bench-scale continuous flow ultrafiltration (UF) membrane process with coagulation/sedimentation pre-treatment. Tests were conducted using both synthetic and real surface water in which norfloxacin and tylosin were added as representative antibiotics at an initial concentration of 0.1 μg/L. In jar tests, the MHCs achieved similar high removal efficiencies (REs) of turbidity and UV254 absorbance, but much higher REs of the two antibiotics (71.7-84.7% and 68.7-76.6% for synthetic and river waters, respectively), compared to several commercial flocculants; the superior performance was attributed to an enhanced hydrophobic interaction and H-bonding between the flocculants and antibiotics. The presence of suspended kaolin particles and humic acid enhanced the antibiotic removal, speculated to be through MHC bridging of the kaolin/humic acid and antibiotic molecules. In the continuous flow tests involving flocculation/sedimentation-UF for 40 days, an optimal MHC achieved a much greater performance than polyaluminium chloride in terms of the overall removal of antibiotics (RE (norfloxacin) of ∼90% and RE (tylosin) of ∼80%) and a greatly reduced rate of membrane fouling; the latter resulting from a more porous and looser structure of cake layer, caused by a surface-modification-like effect of residual MHC on the hydrophobic PVDF membrane. The results of this study have shown that MHCs offer a significant advance over the use of existing flocculants for the treatment of surface water.
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Affiliation(s)
- Zhen Yang
- School of Chemistry and Materials Science, Jiangsu Provincial Key Laboratory of Materials Cycling and Pollution Control, Nanjing Normal University, Nanjing, 210023, PR China.
| | - Tianyang Hou
- School of Chemistry and Materials Science, Jiangsu Provincial Key Laboratory of Materials Cycling and Pollution Control, Nanjing Normal University, Nanjing, 210023, PR China.
| | - Jiangya Ma
- School of Civil Engineering and Architecture, Anhui University of Technology, Maanshan, Anhui, 243002, China.
| | - Bo Yuan
- Jiangsu Sinography Testing Co., Ltd., Nanjing, 210061, PR China.
| | - Ziqi Tian
- Ningbo Institute of Materials Technology & Engineering, Chinese Academy of Sciences, Ningbo, 315000, PR China.
| | - Weiben Yang
- School of Chemistry and Materials Science, Jiangsu Provincial Key Laboratory of Materials Cycling and Pollution Control, Nanjing Normal University, Nanjing, 210023, PR China.
| | - Nigel J D Graham
- Department of Civil and Environmental Engineering, Imperial College London, South Kensington Campus, London, SW7 2AZ, UK.
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26
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Zhao Y, Chi Y, Tian C, Liu Y, Li H, Wang A. Recycling of titanium-coagulated algae-rich sludge for enhanced photocatalytic oxidation of phenolic contaminants through oxygen vacancy. WATER RESEARCH 2020; 177:115789. [PMID: 32304907 DOI: 10.1016/j.watres.2020.115789] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/28/2020] [Revised: 03/16/2020] [Accepted: 04/02/2020] [Indexed: 06/11/2023]
Abstract
In the 21st century, sludge disposal and resource recycling are global issues. Titanium coagulation has received increasing attention due its strong coagulation capability and sludge recycling. Titanium coagulation is highly efficient for the treatment of algae-laden micro-polluted surface water; however, the safe disposal of titanium-coagulated algae-rich sludge remains a challenge. Here, we report on the recycling of titanium-coagulated algae-rich sludge for the production of functional TiO2 nanoflowers (TNFs) through a simple hydrothermal and calcination process. Anatase TNFs (particle size of 10-15 nm) with petal-like structures (mesoporous), relatively high specific surface areas, i.e. 299.4 m2g-1, and low band gaps, i.e. 2.67 eV (compared to P-25), were obtained. Additionally, oxygen vacancy (OV) was generated on the surface of the recycled TNFs based on electron paramagnetic resonance (EPR) results, which were verified by the first-principles calculations within density-functional theory. These TNFs display high photocatalytic performance for the degradation of diverse phenolic organic contaminants, such as bisphenol A, diphenyl phenol, p-tert-butyl phenol, and resorcinol, i.e. > 95%, under mild ultraviolet light irradiation and without any sacrificial reagents. Formation of OV on TNFs not only efficiently inhibited the recombination of photo-generated electrons and holes but also facilitated contaminant adsorption and photo-generated electron transfer on the surface of the recycled TNFs, thereby promoting the generation of holes and hydroxyl and superoxide radicals which were regarded as the reactive oxygen species for attacking contaminants in the reactions. This study proposes a new perspective on recycling chemical-coagulated sludge for producing functional nanomaterials as photocatalysts.
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Affiliation(s)
- Yanxia Zhao
- School of Water Conservancy and Environment, University of Jinan, 250022, Jinan, Shandong, China.
| | - Yuantong Chi
- School of Water Conservancy and Environment, University of Jinan, 250022, Jinan, Shandong, China
| | - Chang Tian
- School of Environmental Science & Engineering, Qilu University of Technology (Shandong Academy of Sciences), 3501 Daxue Road, 250353, Jinan, Shandong, China
| | - Yan Liu
- School of Water Conservancy and Environment, University of Jinan, 250022, Jinan, Shandong, China
| | - Haibo Li
- Environmental Engineering Department, Research Development Center, China Vanke Co., Ltd., 518083, Shenzhen, China
| | - Aizhu Wang
- Shandong Collaborative Innovation Center of Technology and Equipment for Biological Diagnosis and Therapy, Institute for Advanced Interdisciplinary Research (iAIR), University of Jinan, Jinan, 250022, China
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27
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Wang Y, Hou T, Yang Z, Zhao L, Wu W, Yang W, Graham NJD. Nitrogen-Free Cationic Starch Flocculants: Flocculation Performance, Antibacterial Ability, and UF Membrane Fouling Control. ACS APPLIED BIO MATERIALS 2020; 3:2910-2919. [PMID: 35025338 DOI: 10.1021/acsabm.9b01129] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
In light of growing concerns about the formation of nitrogen-based disinfection byproducts (N-DBP) and the possible contribution from the use of quaternary-ammonium-containing flocculants, there is growing interest in the alternative use of quaternary phosphonium salts, which have been reported to have a lower DBP formation potential, stronger cationic properties, lower cytotoxicity, and greater stability. In this study, the performance of N-free quaternary-phosphonium-modified starch flocculants (S-BTP), synthesized through a facile one-step method using commercially available raw materials, in the treatment of bacteria-laden waters (E. coli as the model bacteria) was assessed in both jar tests and a bench-scale continuous-flow flocculation-sedimentation-ultrafiltration process. In jar tests, the effects of the cationic degree of substitution (DS) and dosage of the flocculant, solution pH, and presence of model contaminants on treatment performance were studied. One particular flocculant (S-BTP3), with a DS of 19.3%, displayed high removal efficiencies of E. coli, turbidity, and UV254 from water, comparable with those of ammonium-based analogues and conventional alum, via a combination of charge attraction, polymer bridging, and antibacterial effects. S-BTP3 also possessed better bactericidal properties (99.4% of E. coli killed) than alum (41.4% killed) and did not cause the release of intracellular substances into the treated water. In the continuous-flow flocculation-sedimentation-UF tests, S-BTP3 was superior to alum in the flocculation and antibacterial performance, and in mitigating UF membrane fouling. The results have clearly demonstrated the multiple benefits of the use of N-free cationic starch flocculants in water treatment as an alternative to conventional chemicals.
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Affiliation(s)
- Yadong Wang
- School of Chemistry and Materials Science, Jiangsu Provincial Key Laboratory of Materials Cycling and Pollution Control, Nanjing Normal University, Nanjing 210023, P.R. China
| | - Tianyang Hou
- School of Chemistry and Materials Science, Jiangsu Provincial Key Laboratory of Materials Cycling and Pollution Control, Nanjing Normal University, Nanjing 210023, P.R. China
| | - Zhen Yang
- School of Chemistry and Materials Science, Jiangsu Provincial Key Laboratory of Materials Cycling and Pollution Control, Nanjing Normal University, Nanjing 210023, P.R. China.,Department of Civil and Environmental Engineering, Imperial College London, South Kensington Campus, London SW72AZ, U.K
| | - Lina Zhao
- School of Chemistry and Materials Science, Jiangsu Provincial Key Laboratory of Materials Cycling and Pollution Control, Nanjing Normal University, Nanjing 210023, P.R. China
| | - Wei Wu
- Jiangsu Academy of Environmental Industry and Technology Co. Ltd, Nanjing 210036, P.R. China
| | - Weiben Yang
- School of Chemistry and Materials Science, Jiangsu Provincial Key Laboratory of Materials Cycling and Pollution Control, Nanjing Normal University, Nanjing 210023, P.R. China
| | - Nigel J D Graham
- Department of Civil and Environmental Engineering, Imperial College London, South Kensington Campus, London SW72AZ, U.K
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Hossain SM, Park MJ, Park HJ, Tijing L, Kim JH, Shon HK. Preparation and characterization of TiO 2 generated from synthetic wastewater using TiCl 4 based coagulation/flocculation aided with Ca(OH) 2. JOURNAL OF ENVIRONMENTAL MANAGEMENT 2019; 250:109521. [PMID: 31521035 DOI: 10.1016/j.jenvman.2019.109521] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/12/2019] [Revised: 08/13/2019] [Accepted: 09/02/2019] [Indexed: 06/10/2023]
Abstract
This study focused on the preparation of undoped and Ca-doped titania from flocculation generated sludge. Initially, TiCl4 was utilised to perform coagulation and flocculation in synthetic wastewater and an optimised dose of coagulant was determined by evaluating the turbidity, dissolved organic carbon (DOC) and zeta potential of the treated water. Later, using Ca(OH)2 as a coagulant aid, the effects on effluent pH, turbidity and DOC removal were investigated. Both Ca-doped and undoped anatase TiO2 were prepared from the flocculated sludge for morphological and photocatalytic evaluation. During the standalone use of TiCl4, maximum turbidity and DOC removal were found at 11.63 and 14.54 mg Ti/L, respectively. At the corresponding coagulant dose, rapid deprotonation of water caused the pH of the effluent to reach below 3.77 mg Ti/L. Whereas, when using Ca(OH)2 as a coagulant aid, a neutral pH (7.26) was attained at a simultaneous dosing of 32.40 mg Ca/L and 14.54 mg Ti/L. When aided with Ca(OH)2, the turbidity removal was further increased by 54.28% and the DOC removal was somewhat similar to the standalone use of TiCl4. TiO2 was prepared by incinerating the collected sludge at 600 °C for 2 h. Both XRD and SEM analysis were conducted to observe the morphology of the prepared titania. The XRD pattern of the TiO2 showed only an anatase phase along with the presence of a high atomic proportion of Ca (4.14%). Consequently, a high amount of Ca atoms inhibited the level of TiO2 phase and no obvious presence of CaO was observed. The prepared Ca-doped TiO2 at the optimised dose of Ca(OH)2 was found to be inferior to the undoped TiO2 during the photodegradation of acetaldehyde. However, a reduced dose of Ca(OH)2 (<15 mg Ca/L) exhibited a substantial increase in photoactivity under UV irradiance.
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Affiliation(s)
- Sayed Mukit Hossain
- School of Civil and Environmental Engineering, Faculty of Engineering and IT, University of Technology, Sydney, P.O. Box 123, Broadway, NSW, 2007, Australia
| | - Myoung Jun Park
- School of Civil and Environmental Engineering, Faculty of Engineering and IT, University of Technology, Sydney, P.O. Box 123, Broadway, NSW, 2007, Australia
| | - Hee Ju Park
- School of Chemical Engineering, Chonnam National University, Gwangju, 61186, South Korea
| | - Leonard Tijing
- School of Civil and Environmental Engineering, Faculty of Engineering and IT, University of Technology, Sydney, P.O. Box 123, Broadway, NSW, 2007, Australia
| | - Jong-Ho Kim
- School of Chemical Engineering, Chonnam National University, Gwangju, 61186, South Korea.
| | - Ho Kyong Shon
- School of Civil and Environmental Engineering, Faculty of Engineering and IT, University of Technology, Sydney, P.O. Box 123, Broadway, NSW, 2007, Australia.
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Wang X, Gan Y, Zhang S. Improved resistance to organic matter load by compositing a cationic flocculant into the titanium xerogel coagulant. Sep Purif Technol 2019. [DOI: 10.1016/j.seppur.2018.10.038] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/28/2022]
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30
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Gao B, Li P, Yang R, Li A, Yang H. Investigation of multiple adsorption mechanisms for efficient removal of ofloxacin from water using lignin-based adsorbents. Sci Rep 2019; 9:637. [PMID: 30679691 PMCID: PMC6346052 DOI: 10.1038/s41598-018-37206-1] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2018] [Accepted: 12/05/2018] [Indexed: 11/09/2022] Open
Abstract
Two series of lignin (LN)-based adsorbents, namely, cross-linked lignin (LNEs) with different crosslinking densities and carboxymethyl cross-linked lignin (LNECs) with various degrees of carboxymethyl substitution, were prepared to remove ofloxacin (OFL), a popular fluoroquinolone (FQ) antibiotic, from water. LNEs and LNECs exhibited satisfactory performance in OFL adsorption. Both of them had high adsorption capacity (the maximum contribution of 0.828 mmol/g), good anti-interference to some inorganic salts, and efficient regeneration and reuse performance. The crosslinking density and degree of carboxymethyl substitution strongly affected the content and distribution of oxygen-containing groups in these LN-based adsorbents, which played important roles in OFL adsorption. The pH dependencies of the adsorption performance of LNEs and LNECs indicated the involvement of multiple adsorption mechanisms, including hydrogen bond, electrostatic attraction, π-π electron-donor-acceptor interactions, and negative charge-assisted hydrogen bond. Different mechanisms were dominant under various pH levels, in a near neutral pH, the synergistic effect of electrostatic attraction and π-π interaction allows LINEs and LINECs to reach maximum adsorption capacity. Five FQs with similar structures and their two sub structural analogs were compared in terms of adsorption behavior and electrostatic potential by density functional theory using quantum chemical calculation. FQs with secondary amino groups and low π electron cloud density readily bound to LN-based adsorbents. Hence, LNEs and LNECs were efficient and environment-friendly adsorbents.
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Affiliation(s)
- Boqiang Gao
- State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Nanjing, 210023, P. R. China
| | - Pei Li
- State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Nanjing, 210023, P. R. China
| | - Ran Yang
- State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Nanjing, 210023, P. R. China
| | - Aimin Li
- State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Nanjing, 210023, P. R. China
| | - Hu Yang
- State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Nanjing, 210023, P. R. China.
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