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Fulvic acid

Zoltán Klencsár, Zoltán Köntös
Lignite is a rich source of humic substances such as humic and fulvic acids that are natural chelating agents with multifold applications in fields ranging from agriculture to biomedicine. Associations of heterogeneous molecular components constitute to their complex and still unresolved structure. In this work we utilize X-band electron paramagnetic resonance (EPR) spectroscopy to characterize Fe3+ and Mn2+ complexation sites in fulvic acid (FA) extracted from lignite. EPR signals of FA-Fe3+ and FA-Mn2+ complexes are identified and investigated in detail under various conditions by the means of a newly developed program code and associated analysis method that yields an accurate description of the low-field ( geff ≈ 10-3) range EPR signal by assuming discrete distributions in the axial ( D) and rhombic (λ) zero field splitting (ZFS) parameters associated with Fe3+ complexation sites...
March 19, 2018: Journal of Physical Chemistry. A
Aleicia Holland, Jenny Stauber, Chris M Wood, Melanie Trenfield, Dianne F Jolley
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...
March 2, 2018: Water Research
Bin Hua, John Yang, Fengjing Liu, Guocheng Zhu, Baolin Deng, Jingdong Mao
Characterization of dissolved organic matter/nitrogen (DOM/DON) is critical in water quality assessment and nutrient management in watershed or ecosystem. This study was to investigate the link between DOM/DON and its source using fluorescence excitation-emission matrix (EEM) spectroscopy coupled with parallel factor analysis (PARAFAC). Water samples were collected from various aquatic systems in a watershed located in central Missouri, including rural watershed with various land use and land cover (LULC), landfill, and constructed wetland...
March 6, 2018: Chemosphere
Heng Dong, Dong Wei, Jinglin Wei, Fei Han, Tao Yan, Malik Saddam Khan, Bin Du, Qin Wei
In present study, the characteristics of soluble microbial products (SMP) were evaluated in aerobic granular sludge system during denitrification process under different chemical oxygen demand/nitrogen (C/N) ratios. Batch experiment showed that the effluent nitrate (NO3 - -N) concentration were 15.24 ± 1.83 and 1.72 ± 1.53 mg/L at C/N ratio of 1 and 6, respectively. For the release of SMP, the protein (PN) and polysaccharide contents increased from 1.23 ± 0.38 and 7.46 ± 1.13 mg/L to 1...
March 9, 2018: Bioprocess and Biosystems Engineering
Bing Liu, Li Gu, Qingfei Li, Guozhong Yu, Chengmei Zhao, Huimin Zhai
Municipal wastewater treatment plant (WWTP) effluent is increasingly used as reclaimed water and as water sources for downstream areas. Effluent dissolved organic nitrogen (DON) is considered to be the precursor to nitrogen disinfection by-products (N-DBPs), which have come into increasing focus due to environmental and public health risks associated with them. Here, we investigated DON removal by pre-ozonation enhanced coagulation and found that: (1) pre-ozonation significantly enhanced the removal of DON, DOC and UV254 by coagulation...
March 7, 2018: Environmental Technology
Sergio Collado, Paula Oulego, Octavio Suárez-Iglesias, Mario Díaz
Humic and fulvic acids constitute humic substances, a complex mixture of many different acids containing carboxyl and phenolate groups, which are not only the principal soil fertility factors but also the main pollutants present in landfill leachates or natural organic matter in water. Due to their low bacterial biodegradability, fungal biodegradation processes are key for their removal. The present study compiles and comments all the available literature on decomposition of aqueous humic substances by fungi or by their extracellular enzymes alone, focusing on the influence of the reaction conditions...
March 3, 2018: Applied Microbiology and Biotechnology
Anna Kjerstine Rosenmai, Frida Niss, Geeta Mandava, Johan Lundqvist, Agneta Oskarsson
Surface water can be contaminated with pollutants from multiple sources and contain a vast number of various chemicals. In vitro bioassays are valuable tools to assess the total bioactivity of micropollutants in water samples. Besides anthropogenic chemicals, natural organic matter (NOM) is ubiquitous in water, which also may have an impact on the bioactivity in water samples. In the present study we investigated concentration-dependent effects of Nordic Aquatic fulvic acid (NA-FA) and Nordic reservoir NOM (NR-NOM) on bioactivity measured by a panel of luciferase reporter gene assays...
February 14, 2018: Chemosphere
Pengkang Jin, Jina Song, Xiaochang C Wang, Xin Jin
In this study, two-dimensional correlation spectroscopy integrated with synchronous fluorescence and infrared absorption spectroscopy was employed to investigate the interaction between humic acids and aluminum coagulant at slightly acidic and neutral pH. Higher fluorescence quenching was produced for fulvic-like and humic-like fractions at pH5. At pH5, the humic-like fractions originating from the carboxylic acid, carboxyl and polysaccharide compounds were bound to aluminum first, followed by the fulvic-like fractions originating from the carboxyl and polysaccharide compounds...
February 2018: Journal of Environmental Sciences (China)
Nan Ye, Zhuang Wang, Se Wang, Hao Fang, Degao Wang
This study investigated the impact of dissolved organic matters (DOM) on the ecological toxicity of aluminum oxide nanoparticles (Al2 O3 NPs) at a relatively low exposure concentration (1 mg L-1 ). The unicellular green alga Scenedesmus obliquus was exposed to Al2 O3 NP suspensions in the presence of DOM (fulvic acid) at various concentrations (1, 10, and 40 mg L-1 ). The results show that the presence of DOM elevated the growth inhibition toxicity of Al2 O3 NPs towards S. obliquus in a dose-dependent manner...
February 22, 2018: Journal of Environmental Science and Health. Part A, Toxic/hazardous Substances & Environmental Engineering
Akin Karci, Elizabeth M Wurtzler, Armah A de la Cruz, David Wendell, Dionysios D Dionysiou
Transformation products and toxicity patterns of microcystin-LR (MC-LR), a common cyanotoxin in freshwaters, during degradation by solar photo-Fenton process were studied in the absence and presence of two major water components, namely fulvic acid and alkalinity. The transformation products m/z 795, 835, 515/1030 and 532 can be formed through attack of OH on the conjugated carbon double bonds of Adda. Transformation products with m/z 1010, 966 and 513 can be generated through the attack of OH on the methoxy group of Adda...
January 2, 2018: Journal of Hazardous Materials
Lathika Varanasi, Erica Coscarelli, Maryam Khaksari, Lynn R Mazzoleni, Daisuke Minakata
Considering the increasing identification of trace organic contaminants in natural aquatic environments, the removal of trace organic contaminants from water or wastewater discharge is an urgent task. Ultraviolet (UV) and UV-based advanced oxidation processes (AOPs), such as UV/hydrogen peroxide (UV/H 2 O 2 ), UV/free chlorine and UV/persulfate, are attractive and promising approaches for the removal of these contaminants due to the high reactivity of active radical species produced in these UV-AOPs with a wide variety of organic contaminants...
February 8, 2018: Water Research
Jiachun Yang, Li Zhang, Kechen Xu, Yongzhen Peng
This study combined spectroscopy techniques to assess the composition of refractory organics and highlighted the potential application of excitation-emission matrix (EEM) fluorescence spectroscopy within future monitoring of coal chemical wastewater treatment by the anammox process. The results showed that the anammox process could effectively degrade refractory organic substances, with fulvic-like, UV-humic acid, and Vis-humic acid component removal efficiencies of 43.61, 53.93, and 100%, respectively. In this study, EEM fluorescence spectroscopy was proven to be an effective method of assessing the removal of dissolved organic nitrogen during anammox treatment of mature coal chemical wastewater...
February 16, 2018: Environmental Science and Pollution Research International
Yunqin Cheng, Yunlu Chen, Juncheng Lu, Jianxin Nie, Yan Liu
The Fenton process is used as a tertiary treatment to remove organic pollutants from the effluent of bio-treated pharmaceutical wastewater (EBPW). The optimal and most appropriate Fenton conditions were determined by an orthogonal array test and single-factor experiments. The removal of chemical oxygen demand (COD) was influenced by the following factors in a descending order: H 2 O 2 /Fe(II) molar ratio > H 2 O 2 dosage > reaction time. Under the most appropriate Fenton conditions (H 2 O 2 /Fe(II) molar ratio of 1:1, H 2 O 2 dosage of 120 mg L -1 and reaction time of 10 min), the COD and dissolved organic carbon (DOC) were removed with efficiencies of 62 and 53%, respectively, which met the national discharge standard (GB 21903-2008) for the Lake Tai Basin, China...
February 16, 2018: Environmental Science and Pollution Research International
Dan Wang, Quang Toan Dinh, Tran Thi Anh Thu, Fei Zhou, Wenxiao Yang, Mengke Wang, Weiwei Song, Dongli Liang
To exploit the plant byproducts from selenium (Se) biofortification and reduce environmental risk of inorganic Se fertilizer, pot experiment was conducted in this study. The effects of Se-enriched wheat (Triticum aestivum L.) straw (WS + Se) and pak choi (Brassica chinensis L.) (P + Se) amendment on organo-selenium speciation transformation in soil and its bioavailability was evaluated by pak choi uptake. The Se contents of the cultivated pak choi in treatments amended with the same amount of Se-enriched wheat straw and pak choi were 1...
February 5, 2018: Chemosphere
Zhixiong Li, Gregory V Lowry, Jin Fan, Fei Liu, Jiawei Chen
Nanoscale zero valent iron particles (nano-Fe0) are attractive for in-situ groundwater remediation due to their high reactivity and ability to degrade many different classes of environmental contaminants. It is expected that adsorbed natural organic matter (NOM), which is heterogeneous and typically has a wide molecular weight (MW) distribution, will affect the reactivity and performance of nano-Fe0 as a remediation agent. However, the interaction of NOM with nano-Fe0 has not been well-studied. In this study, we used high performance size exclusion chromatography (HPSEC) to determine if there was preferential sorption of the high MW fraction of NOM onto nano-Fe0 that have a Fe0 core and a Fe-oxide shell (predominantly magnetite)...
February 9, 2018: Science of the Total Environment
Haifeng Zhang, Min Yang
To date, study on the speciation of brominated disinfection byproducts (Br-DBPs), which have higher cytotoxicity and genotoxicity than their analogous chlorinated DBPs (Cl-DBPs), formed in chloramination is still limited. In this study, the previous unknown Br-DBPs formed during chloramination of artificial drinking water were explored with electrospray ionization ultrahigh resolution Fourier transform ion cyclotron resonance mass spectrometry (ESI FT-ICR MS). In total, 193 formulae of one bromine containing Br-DBPs and 5 formulae of two bromine containing Br-DBPs were detected in the chloraminated artificial drinking water sample...
January 28, 2018: Science of the Total Environment
Lu Fan, Anlan Zhou, Linrui Zhong, Yong Liu
In order to recover mercury from high concentration Hg(II) acid wastewater, UV irradiation was used to reduce Hg(II) to Hg2Cl2 with the presence of fulvic acid and chloride ion. When simulated wastewater with Hg(II) concentration of 1000 mg L-1 was treated, > 90% of Hg(II) removal efficiency was achieved under the condition of extra Cl- dosage of 5 g L-1, FA dosage of 2 g L-1, pH of 3.0 and 120 min of UV irradiation. Kinetics study showed that the photoreduction process could be well described by pseudo-first order kinetic mode, and the Hg(II) reduction rate was tested to be 0...
February 2, 2018: Chemosphere
Chao Qin, Wei Zhang, Bing Yang, Xuwen Chen, Kang Xia, Yanzheng Gao
The sorption of polycyclic aromatic hydrocarbons (PAHs) to montmorillonites is largely influenced by their interactions with dissolved organic matter (DOM). However, the role of DOM rather than humic and fulvic acids (e.g., extracellular DNA) in the PAH sorption to soil clays is little known. Here we demonstrated that extracellular double-stranded salmon testes DNA substantially increased the sorption of phenanthrene and pyrene to Na-, Ca-, and Fe-modified montmorillonites. All PAH sorption isotherms fitted the linear and Freundlich models reasonably well (R2 = 0...
February 8, 2018: Environmental Science & Technology
Haiming Tang, Xiaoping Xiao, Chao Li, Ke Wang, Lijun Guo, Kaikai Cheng, Geng Sun, Xiaochen Pan
Soil organic matter (SOM) content and soil aggregation are essential components of soil structure, which plays an important role in soil quality and fertility. Also, the SOM content, aggregation, and humus substances in paddy field were affected by application of fertilization practices. However, there is still limited information about the effects of long-term different fertilization practices on soil aggregation and carbon content in the humic acid (C-HAF), fulvic acid (C-FAF), and humin (C-HUM) fractions under double-cropping rice (Oryza sativa L...
February 6, 2018: Environmental Science and Pollution Research International
Shuhei Shinohara, Namsoon Eom, E-Jen Teh, Kaoru Tamada, Drew Francis Parsons, Vincent S J Craig
The interactions between colloidal particles and nanoparticles determines solution stability and the structures formed when the particles are unstable to flocculation. Therefore knowledge of the inter-particle interactions is important for understanding the transport, dissolution and fate of particles in the environment. The interactions between particles are governed by the surface properties of the particles, which are altered when species adsorb to the surface. The important interactions in the environment are almost never those between the bare particles but rather those between particles that have been modified by the adsorption of natural organic materials...
February 6, 2018: Langmuir: the ACS Journal of Surfaces and Colloids
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