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Shen Q, Zhao T, Wawryk NJP, Chau KNM, Zhang D, Carroll K, Chu W, Huan T, Li XF. Nontargeted Analysis of Reactive Nitrogenous Compounds in Suwannee River Standard Reference Materials and Authentic River Water Samples. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2024; 58:15807-15815. [PMID: 39163399 PMCID: PMC11375767 DOI: 10.1021/acs.est.4c05165] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 08/22/2024]
Abstract
Concerns over toxic nitrogenous disinfection byproducts (N-DBPs) necessitate identifying their precursors in source water. Natural organic amino compounds are known precursors to N-DBPs. Three Suwannee River (SR) standard reference materials (SRMs), humic acids (HA), fulvic acids (FA), and natural organic matter (NOM), are commonly used to study DBP formation, but the chemical makeup of amino compounds in SRSRMs remains largely unknown. To address this, we combined stable hydrogen/deuterium isotope labeling, HDPairFinder bioinformatics, and nontargeted high-performance liquid chromatography-high-resolution mass spectrometry (HPLC-HRMS) to characterize these compounds in SRSRMs. This method classifies reactive amines, provides accurate masses and MS/MS spectra, and quantifies intensities. We identified 2707 high-quality features with primary and/or secondary amines in SRSRMs and 75% of them having an m/z < 300. Across all three SRSRMs, 327 amino features were detected, while 856, 794, and 200 unique features were found in SRNOM, SRHA, and SRFA, respectively. In North Saskatchewan River (NSR) samples, a total of 6449 amino features were detected, 818 of them matched those in SRSRMs, and 87% of them were different between the two rivers. Using chemical standards, we confirmed 10 compounds and tentatively identified 5 more. This study highlights similarities and differences in reactive N-precursors in SRSRMs and local river water, enhancing the understanding of geo-differences in reactive N-precursors in different source waters.
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Affiliation(s)
- Qiming Shen
- Division of Analytical and Environmental Toxicology, Department of Laboratory Medicine and Pathology, Faculty of Medicine and Dentistry, University of Alberta, Edmonton, Alberta T6G 2G3, Canada
| | - Tingting Zhao
- Department of Chemistry, Faculty of Science, University of British Columbia, Vancouver Campus, 2036 Main Mall, Vancouver, British Columbia V6T 1Z1, Canada
| | - Nicholas J P Wawryk
- Division of Analytical and Environmental Toxicology, Department of Laboratory Medicine and Pathology, Faculty of Medicine and Dentistry, University of Alberta, Edmonton, Alberta T6G 2G3, Canada
| | - K N Minh Chau
- Division of Analytical and Environmental Toxicology, Department of Laboratory Medicine and Pathology, Faculty of Medicine and Dentistry, University of Alberta, Edmonton, Alberta T6G 2G3, Canada
| | - Di Zhang
- Division of Analytical and Environmental Toxicology, Department of Laboratory Medicine and Pathology, Faculty of Medicine and Dentistry, University of Alberta, Edmonton, Alberta T6G 2G3, Canada
- State Key Laboratory of Pollution Control and Resources Reuse, College of Environmental Science and Engineering, Tongji University, Shanghai 200092, China
| | - Kristin Carroll
- Division of Analytical and Environmental Toxicology, Department of Laboratory Medicine and Pathology, Faculty of Medicine and Dentistry, University of Alberta, Edmonton, Alberta T6G 2G3, Canada
| | - Wenhai Chu
- State Key Laboratory of Pollution Control and Resources Reuse, College of Environmental Science and Engineering, Tongji University, Shanghai 200092, China
| | - Tao Huan
- Department of Chemistry, Faculty of Science, University of British Columbia, Vancouver Campus, 2036 Main Mall, Vancouver, British Columbia V6T 1Z1, Canada
| | - Xing-Fang Li
- Division of Analytical and Environmental Toxicology, Department of Laboratory Medicine and Pathology, Faculty of Medicine and Dentistry, University of Alberta, Edmonton, Alberta T6G 2G3, Canada
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Wang J, Yan H, Xin K, Tao T. Iron stability on the inner wall of prepared polyethylene drinking pipe: Effects of multi-water quality factors. THE SCIENCE OF THE TOTAL ENVIRONMENT 2019; 658:1006-1012. [PMID: 30677965 DOI: 10.1016/j.scitotenv.2018.12.127] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/25/2018] [Revised: 12/09/2018] [Accepted: 12/09/2018] [Indexed: 06/09/2023]
Abstract
Iron is currently one of the main contaminants of drinking water. The inner walls of drinking pipes can cause iron to release in water chemistry, which alters the water quality, including its chloride, sulfate, bicarbonate, pH, and humic acid (HA) levels. Hence, the goal of this research was to improve our understanding of the multi-water quality factors affecting iron release in polyethylene pipes. An array of bench-scale experiments were conducted exposing model water with different concentrations of chloride, sulfate, bicarbonate, HA, and different pH levels to prepared polyethylene pipes following the response surface methodology. The single role of HA during iron release is also evaluated by changing its concentration. A comprehensive study revealed that regression models could be used to describe the relationship between the five water quality parameters and iron release. The coefficients of determination were 0.890 and 0.870 for the fitting equations of total and soluble iron concentrations in water, respectively. In the presence of HA, the concentration of iron in water increased more rapidly than that for the other four factors (chloride, sulfate, bicarbonate, and pH). In addition, the Visual MINTEQ results suggest that a lower HA concentration tended to increase the degree of saturation of iron solids. In turn, this limits iron release and considerably increases the iron concentration in water.
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Affiliation(s)
- Jiaying Wang
- Shanghai Institute of Pollution Control and Ecological Security, College of Environmental Science and Engineering, Tongji University, Siping Road, Shanghai 200092, PR China
| | - Hexiang Yan
- Shanghai Institute of Pollution Control and Ecological Security, College of Environmental Science and Engineering, Tongji University, Siping Road, Shanghai 200092, PR China
| | - Kunlun Xin
- Shanghai Institute of Pollution Control and Ecological Security, College of Environmental Science and Engineering, Tongji University, Siping Road, Shanghai 200092, PR China
| | - Tao Tao
- Shanghai Institute of Pollution Control and Ecological Security, College of Environmental Science and Engineering, Tongji University, Siping Road, Shanghai 200092, PR China; UN Environment-Tongji Institute of Environment for Sustainable Development, Siping Road, Shanghai 200092, PR China.
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Su H, Yang R, Li Y, Wang X. Influence of humic substances on iron distribution in the East China Sea. CHEMOSPHERE 2018; 204:450-462. [PMID: 29679866 DOI: 10.1016/j.chemosphere.2018.04.018] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/20/2017] [Revised: 03/31/2018] [Accepted: 04/03/2018] [Indexed: 06/08/2023]
Abstract
The influence of humic substances (specifically humic and fulvic acids, referred to as HS-HA and HS-FA) as well as other factors, such as major nutrient concentrations of total dissolved nitrogen (TDN), total dissolved phosphate (TDP) and hydrologic factors, on the distribution of total dissolved iron (DFe) and the chemical speciation of DFe was studied in the East China Sea (ECS) during a summer cruise in 2013. As the wide rage fraction of nature organic matter, the HS-HA, HS-FA in ESC contains most part of the organic ligand (Lt) of DFe. The concentrations of HS-HA, DFe and Lt in coastal water masses were higher than those in the water masses affected by the Kuroshio Current. The highest concentrations of HS-HA and DFe were observed in surface water at stations MT1 and MC4, with the value of 336.5 μg SRHA/L and 20.3 nmol/L, respectively, whereas, the lowest concentrations of HS-HA and DFe were observed in surface waters with the value of 149.6 μg SRHA/L and 0.4 nmol/L, respectively. HS-HA concentrations were more conservative than that of DFe. The DFe which were combined by unit weight HS-HA (mg-1, IB) in the surface and bottom waters quickly decreased with increasing salinities from the Yangtze River estuary to the southeast of the ECS. Average IB values in bottom waters were higher than those in surface waters. This study indicated that Yangtze River dilution water and cold water from the Yellow Sea were the main source of HS-HA and DFe in ECS.
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Affiliation(s)
- Han Su
- College of Chemistry and Chemical Engineering, Ocean University of China, 238 Songling Road, Qingdao 266100, PR China
| | - Rujun Yang
- College of Chemistry and Chemical Engineering, Ocean University of China, 238 Songling Road, Qingdao 266100, PR China.
| | - Yan Li
- College of Chemistry and Chemical Engineering, Ocean University of China, 238 Songling Road, Qingdao 266100, PR China
| | - Xuchen Wang
- College of Chemistry and Chemical Engineering, Ocean University of China, 238 Songling Road, Qingdao 266100, PR China
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Holland A, Stauber J, Wood CM, Trenfield M, Jolley DF. Dissolved organic matter signatures vary between naturally acidic, circumneutral and groundwater-fed freshwaters in Australia. WATER RESEARCH 2018; 137:184-192. [PMID: 29549800 DOI: 10.1016/j.watres.2018.02.043] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/12/2017] [Revised: 02/14/2018] [Accepted: 02/17/2018] [Indexed: 06/08/2023]
Abstract
Dissolved organic matter (DOM) plays important roles in both abiotic and biotic processes within aquatic ecosystems, and these in turn depend on the quality of the DOM. We collected and characterized chromophoric DOM (CDOM) from different Australian freshwater types (circumneutral, naturally acidic and groundwater-fed waterways), climatic regions and seasons. CDOM quality was characterized using absorbance and fluorescence spectroscopy. Excitation emission scans followed by parallel factor (PARAFAC) analysis showed that CDOM was characterized by three main components: protein-like, fulvic-like and humic-like components commonly associated with various waters globally in the Openfluor database. Principal component analysis showed that CDOM quality varied between naturally acidic, circumneutral and groundwater-fed waters, with unique CDOM quality signatures shown for each freshwater type. CDOM quality also differed significantly within some sites between seasons. Clear differences in dominant CDOM components were shown between freshwater types. Naturally acidic waters were dominated by highly aromatic (as indicated by the specific absorbance co-efficient (SAC340) and the specific UV absorbance (SUVA254) values which ranged between 31 and 50 cm2 mg-1 and 3.9-5.7 mg C-1 m-1 respectively), humic-like CDOM of high molecular weight (as indicated by abs254/365 which ranged from 3.8 to 4.3). In contrast, circumneutral waters were dominated by fulvic-like CDOM of lower aromaticity (SAC340: 7-21 cm2 mg-1 and SUVA254: 1.5-3.0 mg C-1 m-1) and lower molecular weight (abs254/365 5.1-9.3). The groundwater-fed site had a higher abundance of protein-like CDOM, which was the least aromatic (SAC340: 2-5 cm2 mg-1 and SUVA254: 0.58-1.1 mg C-1 m-1). CDOM was generally less aromatic, of a lower molecular weight and more autochthonous in nature during the summer/autumn sampling compared to winter/spring. Significant relationships were shown between various CDOM quality parameters and pH. This is the first study to show that different freshwater types (circumneutral, naturally acidic and groundwater-fed) contain distinct CDOM quality signatures in Australia, a continent with unique flora and geology.
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Affiliation(s)
- Aleicia Holland
- La Trobe University, School of Life Science, Department of Ecology, Environment and Evolution, Murray Darling Freshwater Research Centre, Albury/Wodonga Campus, Vic, Australia; CSIRO Land and Water, Lucas Heights, NSW, Australia; University of Wollongong, School of Chemistry, Centre for Molecular and Medical Biosciences, Wollongong, NSW, Australia.
| | | | - Chris M Wood
- University of British Columbia, Department of Zoology, Vancouver, BC, Canada
| | - Melanie Trenfield
- Environmental Research Institute of the Supervising Scientist, GPO Box 461, Darwin, NT, Australia
| | - Dianne F Jolley
- University of Wollongong, School of Chemistry, Centre for Molecular and Medical Biosciences, Wollongong, NSW, Australia
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Yang R, Su H, Qu S, Wang X. Capacity of humic substances to complex with iron at different salinities in the Yangtze River estuary and East China Sea. Sci Rep 2017; 7:1381. [PMID: 28469240 PMCID: PMC5431113 DOI: 10.1038/s41598-017-01533-6] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2016] [Accepted: 03/30/2017] [Indexed: 11/09/2022] Open
Abstract
The iron binding capacities (IBC) of fulvic acid (FA) and humic acid (HA) were determined in the salinity range from 5 to 40. The results indicated that IBC decreased while salinity increased. In addition, dissolved iron (dFe), FA and HA were also determined along the Yangtze River estuary’s increasing salinity gradient from 0.14 to 33. The loss rates of dFe, FA and HA in the Yangtze River estuary were up to 96%, 74%, and 67%, respectively. The decreases in dFe, FA and HA, as well as the change in IBC of humic substances (HS) along the salinity gradient in the Yangtze River estuary were all well described by a first-order exponential attenuation model: y(dFe/FA/HA, S) = a0 × exp(kS) + y0. These results indicate that flocculation of FA and HA along the salinity gradient resulted in removal of dFe. Furthermore, the exponential attenuation model described in this paper can be applied in the major estuaries of the world where most of the removal of dFe and HS occurs where freshwater and seawater mix.
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Affiliation(s)
- Rujun Yang
- College of Chemistry and Chemical Engineering, Ocean University of China, Songling Road 238, Qingdao, 266100, P.R. China.
| | - Han Su
- College of Chemistry and Chemical Engineering, Ocean University of China, Songling Road 238, Qingdao, 266100, P.R. China
| | - Shenglu Qu
- College of Chemistry and Chemical Engineering, Ocean University of China, Songling Road 238, Qingdao, 266100, P.R. China
| | - Xuchen Wang
- College of Chemistry and Chemical Engineering, Ocean University of China, Songling Road 238, Qingdao, 266100, P.R. China
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Ren D, Huang B, Yang B, Pan X, Dionysiou DD. Mitigating 17α-ethynylestradiol water contamination through binding and photosensitization by dissolved humic substances. JOURNAL OF HAZARDOUS MATERIALS 2017; 327:197-205. [PMID: 28068644 DOI: 10.1016/j.jhazmat.2016.12.054] [Citation(s) in RCA: 31] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/19/2016] [Revised: 12/25/2016] [Accepted: 12/27/2016] [Indexed: 06/06/2023]
Abstract
Photodegradation is an important abiotic pathway transforming organic pollutants in natural waters. Humic substances (HS), including humic and fulvic acids, are capable of accelerating the photodegradation of steroid estrogens. However, how the photodegradtion of the emerging pollutants influenced by HS is not clear. Thus, we studied the roles and mechanisms of HS in inducing the photodegradation of 17α-ethynylestradiol (EE2). HS generally induces EE2 photodegradation through binding and reactive species generation. Apart from hydroxyl radical (HO), the excited triplets of humic substances (3HS*) are other key reactive species degrading EE2 by abstracting electrons. HO and 3HS* were responsible for about 60% of the overall EE2 photodegradation at 250μmol HS L-1. Most of EE2 molecules bound to the HS via H-bonding, π-π and hydrophobic interactions. The binding role of HS in promoting EE2 photodegradation was rationalized by 17β-estradiol competitive binding with EE2 to the humic and fulvic acids. Furthermore, HS-promoted photodegradation can alter EE2 toxicity to wheat, rice and Ormosia plants. This study extends our knowledge on the photochemical behaviors and ecological risks of steroid estrogens in natural waters.
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Affiliation(s)
- Dong Ren
- Faculty of Environmental Science and Engineering, Kunming University of Science and Technology, Kunming, Yunnan 650500, China
| | - Bin Huang
- Faculty of Environmental Science and Engineering, Kunming University of Science and Technology, Kunming, Yunnan 650500, China
| | - Benqin Yang
- Faculty of Environmental Science and Engineering, Kunming University of Science and Technology, Kunming, Yunnan 650500, China
| | - Xuejun Pan
- Faculty of Environmental Science and Engineering, Kunming University of Science and Technology, Kunming, Yunnan 650500, China.
| | - Dionysios D Dionysiou
- Environmental Engineering and Science Program, Department of Biomedical, Chemical, and Environmental Engineering, University of Cincinnati, Cincinnati, OH 45221, USA.
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Ren D, Huang B, Yang B, Chen F, Pan X, Dionysiou DD. Photobleaching alters the photochemical and biological reactivity of humic acid towards 17α-ethynylestradiol. ENVIRONMENTAL POLLUTION (BARKING, ESSEX : 1987) 2017; 220:1386-1393. [PMID: 27825843 DOI: 10.1016/j.envpol.2016.10.096] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/25/2016] [Revised: 10/21/2016] [Accepted: 10/31/2016] [Indexed: 06/06/2023]
Abstract
Dissolved humic acid (HA) is ubiquitous in natural waters. Its presence significantly changes the photo-and bio-degradation of some organic pollutants in natural waters. The effects of photobleaching on the composition, photosensitizing property and bioavailability of HA were investigated here along with the subsequent influence on its photochemical and biological reactivity in mediating 17α-ethynylestradiol (EE2) degradation. Photobleaching transformed the refractory HA into some small molecules, including organic acids and aliphatics. Along with composition alteration, the photochemical reactivity of HA towards EE2 was slightly depressed, with 9% of the removal rate inhibited by a 70-h photobleaching. Contrarily, the reactivity of HA in mediating EE2 biodegradation by E. coli was significantly promoted by a short-term photobleaching. Compared to the biodegradation of EE2 in the pristine HA, the 10-h photobleached HA increased the biodegradation removal rate of EE2 by 25%, reaching its peak value of about 60%. However, the EE2 biodegradation was inhibited by further irradiation, and the removal rate of EE2 decreased to that in the pristine HA systems. Because no substrate competition was found between EE2 and formate or glucose, EE2 biodegradation mediated by HA in natural waters may not be affected by coexistent organics. Photodegradation and biodegradation of EE2 mediated by HA thus can be combined together by photobleaching to remove pollutants from natural waters. The results reported here could assist environmental risk assessment with respect to EE2 in natural aquatic systems.
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Affiliation(s)
- Dong Ren
- Faculty of Environmental Science and Engineering, Kunming University of Science and Technology, Kunming 650500, China
| | - Bin Huang
- Faculty of Environmental Science and Engineering, Kunming University of Science and Technology, Kunming 650500, China
| | - Benqin Yang
- Faculty of Environmental Science and Engineering, Kunming University of Science and Technology, Kunming 650500, China
| | - Fang Chen
- College of Environmental Science and Engineering, China West Normal University, Nanchong 637009, China
| | - Xuejun Pan
- Faculty of Environmental Science and Engineering, Kunming University of Science and Technology, Kunming 650500, China.
| | - Dionysios D Dionysiou
- Department of Biomedical, Chemical, and Environmental Engineering, University of Cincinnati, Cincinnati, OH 45221, USA.
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Fang K, Yuan D, Zhang L, Feng L, Chen Y, Wang Y. Effect of environmental factors on the complexation of iron and humic acid. J Environ Sci (China) 2015; 27:188-196. [PMID: 25597677 DOI: 10.1016/j.jes.2014.06.039] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2014] [Revised: 06/16/2014] [Accepted: 06/16/2014] [Indexed: 06/04/2023]
Abstract
A method of size exclusion chromatography coupled with ultraviolet spectrophotometry and off-line graphite furnace atomic absorption spectrometry was developed to assess the complexation properties of iron (Fe) and humic acid (HA) in a water environment. The factors affecting the complexation of Fe and HA, such as ionic strength, pH, temperature and UV radiation, were investigated. The Fe-HA complex residence time was also studied. Experimental results showed that pH could influence the deprotonation of HA and hydrolysis of Fe, and thus affected the complexation of Fe and HA. The complexation was greatly disrupted by the presence of NaCl. Temperature had some influence on the complexation. The yield of Fe-HA complexes showed a small decrease at high levels of UV radiation, but the effect of UV radiation on Fe-HA complex formation at natural levels could be neglected. It took about 10 hr for the complexation to reach equilibrium, and the Fe-HA complex residence time was about 20 hr. Complexation of Fe and HA reached a maximum level under the conditions of pH 6, very low ionic strength, in the dark and at a water temperature of about 25°C, for 10 hr. It was suggested that the Fe-HA complex could form mainly in freshwater bodies and reach high levels in the warm season with mild sunlight radiation. With changing environmental parameters, such as at lower temperature in winter or higher pH and ionic strength in an estuary, the concentration of the Fe-HA complex would decrease.
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Affiliation(s)
- Kai Fang
- State Key Laboratory of Marine Environmental Science, College of the Environment and Ecology, Xiamen University, Xiamen 361102, China.
| | - Dongxing Yuan
- State Key Laboratory of Marine Environmental Science, College of the Environment and Ecology, Xiamen University, Xiamen 361102, China.
| | - Lei Zhang
- State Key Laboratory of Marine Environmental Science, College of the Environment and Ecology, Xiamen University, Xiamen 361102, China.
| | - Lifeng Feng
- State Key Laboratory of Marine Environmental Science, College of the Environment and Ecology, Xiamen University, Xiamen 361102, China.
| | - Yaojin Chen
- State Key Laboratory of Marine Environmental Science, College of the Environment and Ecology, Xiamen University, Xiamen 361102, China.
| | - Yuzhou Wang
- State Key Laboratory of Marine Environmental Science, College of the Environment and Ecology, Xiamen University, Xiamen 361102, China.
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Rodríguez FJ, Schlenger P, García-Valverde M. A comprehensive structural evaluation of humic substances using several fluorescence techniques before and after ozonation. Part I: structural characterization of humic substances. THE SCIENCE OF THE TOTAL ENVIRONMENT 2014; 476-477:718-730. [PMID: 24364992 DOI: 10.1016/j.scitotenv.2013.11.150] [Citation(s) in RCA: 65] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/03/2013] [Revised: 11/26/2013] [Accepted: 11/29/2013] [Indexed: 06/03/2023]
Abstract
The main objective of this work (Part I) is to conduct a comprehensive structural characterization of humic substances, using all the current fluorescence techniques: emission scan fluorescence (ESF), synchronous fluorescence spectroscopy (SFS), total luminescence spectroscopy (TLS or EEM) through the use of both 2-D contour maps and 3-D plots, fluorescence index and the λ0.5 parameter. Four humic substances were studied in this work: three of them were provided by the International Humic Substances Society (Suwannee River Fulvic Acid Standard, Suwannee River Humic Acid Standard and Nordic Reservoir Fulvic Acid Reference) and the other one was a commercial humic acid widely used as a surrogate for aquatic humic substances in various studies (Aldrich Humic Acid: ALHA). The EEM spectra for the three natural aquatic substances were quite similar, showing two main peaks of maximum fluorescence intensity: one located in the ultraviolet region and centered at around Ex/Em values of 230/437 nm (peak A) and another one in the visible region, centered at around 335/460 nm (peak C); however, the EEM spectrum of ALHA is completely different to those of natural aquatic humic substances, presenting four poorly resolved main peaks with a high degree of spectral overlap, located at 260/462, 300/479, 365/483 and 450/524 nm. The synchronous spectra at Δλ=18 and 44 nm (especially at Δλ=18 nm) allowed the identification of a protein-like peak at λsyn around 290 nm, which was not detected in the EEM spectra; as it happened with EEM spectra, the synchronous spectra of ALHA are quite different from those of the aquatic humic substances, presenting a higher number of bands that suggest greater structural complexity and a higher degree of polydispersity. Good correlations were achieved between (13)C NMR aromaticity and both fluorescence index and λ0.5 parameter. The different spectra presented by ALHA compared to those shown by the natural aquatic humic substances for all the fluorescence techniques studied suggest an important structural difference between them, which cast doubt on the use of commercial humic acids as surrogates for natural humic substances.
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Affiliation(s)
- Francisco J Rodríguez
- Department of Chemistry, Higher Polytechnic School, University of Burgos, Av. Cantabria s/n, 09006 Burgos, Spain.
| | - Patrick Schlenger
- Department of Chemistry & Biology, Faculty of Mathematics and Natural Science, University of Wuppertal, Germany.
| | - María García-Valverde
- Department of Chemistry, Faculty of Sciences, University of Burgos, Pz. Misael Bañuelos s/n, 09001 Burgos, Spain.
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Rodríguez FJ, Schlenger P, García-Valverde M. A comprehensive structural evaluation of humic substances using several fluorescence techniques before and after ozonation. Part II: evaluation of structural changes following ozonation. THE SCIENCE OF THE TOTAL ENVIRONMENT 2014; 476-477:731-742. [PMID: 24364994 DOI: 10.1016/j.scitotenv.2013.11.149] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/03/2013] [Revised: 11/26/2013] [Accepted: 11/29/2013] [Indexed: 06/03/2023]
Abstract
The main objective of this work (Part II) is to evaluate the usefulness of fluorescence techniques to monitor structural changes in humic substances produced by the ozonation treatment, using all the current fluorescence techniques: Emission scan fluorescence (ESF), synchronous fluorescence spectroscopy (SFS), total luminescence spectroscopy (TLS or EEM) through the use of both 2-D contour maps and 3-D plots, fluorescence index and the λ0.5 parameter. Four humic substances were studied in this work: three of them were provided by the International Humic Substances Society (Suwannee River Fulvic Acid Standard: SUFA, Suwannee River Humic Acid Standard: SUHA and Nordic Reservoir Fulvic Acid Reference: NOFA) and the other one was a commercial humic acid widely used as a surrogate for aquatic humic substances in various studies (Aldrich Humic Acid: ALHA). The lowest ozone dosage tested (0.25mg O3/mg TOC) caused no appreciable change in the different types of fluorescence spectra under study, therefore the structural change produced in the humic macromolecules may be considered of little significance. Concerning EEM and synchronous spectra, the two natural fulvic acids (SUFA and NOFA) showed a decrease in fluorescence intensity as ozone dosage increased, but the natural humic acid (SUHA) showed a different behaviour: an initial increase in fluorescence intensity at medium ozone dosages (1.5 mg O3/mg TOC) followed by an intensity decrease for the higher ozone dose (7.5 mg O3/mg TOC). Regarding synchronous spectra, the moderate dosage of 1.5 mg O3/mg TOC led to an increase in the fluorescence of the protein-like peak at λsyn=285 nm for the natural humic substances. The results obtained for the fluorescence index and λ0.5 may suggest that the greatest degradation of aromatic structures within the humic macromolecule occurs at high ozone dosages, whereas the predominant effect at moderate dosages would be the break-up of the humic macromolecule into lower molecular weight fragments. The behaviour of the commercial humic acid (ALHA) upon ozonation was very different from that of the natural humic substances (SUFA, SUHA and NOFA), a result that was confirmed with all the fluorescence techniques used in this study and that would cast doubt on the use of commercial humic acids as surrogates for natural humic substances.
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Affiliation(s)
- Francisco J Rodríguez
- Department of Chemistry, Higher Polytechnic School, University of Burgos, Av. Cantabria s/n, 09006 Burgos, Spain.
| | - Patrick Schlenger
- Department of Chemistry & Biology, Faculty of Mathematics and Natural Science, University of Wuppertal, Germany.
| | - María García-Valverde
- Department of Chemistry, Faculty of Sciences, University of Burgos, Pz. Misael Bañuelos s/n, 09001 Burgos, Spain.
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Schriewer A, Wehlmann A, Wuertz S. Improving qPCR efficiency in environmental samples by selective removal of humic acids with DAX-8. J Microbiol Methods 2011; 85:16-21. [DOI: 10.1016/j.mimet.2010.12.027] [Citation(s) in RCA: 62] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2010] [Revised: 12/20/2010] [Accepted: 12/22/2010] [Indexed: 11/15/2022]
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Trenfield MA, McDonald S, Kovacs K, Lesher EK, Pringle JM, Markich SJ, Ng JC, Noller B, Brown PL, van Dam RA. Dissolved organic carbon reduces uranium bioavailability and toxicity. 1. Characterization of an aquatic fulvic acid and its complexation with uranium[VI]. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2011; 45:3075-3081. [PMID: 21351802 DOI: 10.1021/es103330w] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/30/2023]
Abstract
Fulvic acid (FA) from a tropical Australian billabong (lagoon) was isolated with XAD-8 resin and characterized using size exclusion chromatography, solid state cross-polarization magic angle spinning, 13C nuclear magnetic resonance spectroscopy, elemental analysis, and potentiometric acid-base titration. Physicochemical characteristics of the billabong FA were comparable with those of the Suwannee River Fulvic Acid (SRFA) standard. The greater negative charge density of the billabong FA suggested it contained protons that were more weakly bound than those of SRFA, with the potential for billabong water to complex less metal contaminants, such as uranium (U). This may subsequently influence the toxicity of metal contaminants to resident freshwater organisms. The complexation of U with dissolved organic carbon (DOC) (10 mg L(-1)) in billabong water was calculated using the HARPHRQ geochemical speciation model and also measured using flow field-flow fractionation combined with inductively coupled plasma mass-spectroscopy. Agreement between both methods was very good (within 4% as U-DOC). The results suggest that in billabong water at pH 6.0, containing an average DOC of 10 mg L(-1) and a U concentration of 90 μg L(-1), around 10% of U is complexed with DOC.
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Affiliation(s)
- Melanie A Trenfield
- Ecotoxicology Program, Environmental Research Institute of the Supervising Scientist, GPO Box 461, Darwin, NT 0801, Australia.
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Tsuda K, Mori H, Asakawa D, Yanagi Y, Kodama H, Nagao S, Yonebayashi K, Fujitake N. Characterization and grouping of aquatic fulvic acids isolated from clear-water rivers and lakes in Japan. WATER RESEARCH 2010; 44:3837-3846. [PMID: 20569962 DOI: 10.1016/j.watres.2010.04.038] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/28/2009] [Revised: 04/13/2010] [Accepted: 04/27/2010] [Indexed: 05/29/2023]
Abstract
Characteristics of aquatic fulvic acids (FAs) from 10 clear waters in Japan (around the temperate zone) were revealed by several analytical techniques-high performance size exclusion chromatography (HPSEC), elemental analysis, liquid-state (13)C NMR spectroscopy, isotopic analyses (delta(13)C and delta(15)N), and compared with those of International Humic Substances Society (IHSS) standard samples including FAs from brown waters (Suwannee, Pony, and Nordic FAs). Generally clear-water FAs were different from brown-water FAs in chemical properties. Weight-average molecular weights (Mw) of the clear-water FAs were similar to each other, whereas their elemental compositions and carbon species distribution were different. The clear-water FAs all exhibited a high proportion of alkyl carbons, which may be attributed to microbial activity. delta(13)C and delta(15)N values of the FAs indicated that there would be a huge gap between origin and chemical structure of clear-water FA. Results of the chemical structural analyses described above were not always linked to those of the isotopic analyses (delta(13)C and delta(15)N). Multivariate statistical analysis, i.e. cluster and principal component analysis was applied to reveal differences or similarities in a more objective manner. The FAs were always classified into two clear-water groups and one brown-water group. Aryl-C and O-Alkyl-C contents were important for the grouping. We speculate that the grouping might depend on the differences of aquatic microbial activity caused by the differences of residence time of water.
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Affiliation(s)
- Kumiko Tsuda
- Graduate School of Science and Technology, Kobe University, Rokkodai 1, Kobe 657-8501, Japan
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