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Fulvic acid

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https://www.readbyqxmd.com/read/28437609/source-and-biological-response-of-biochar-organic-compounds-released-into-water-relationships-with-bio-oil-composition-and-carbonization-degree
#1
Michele Ghidotti, Daniele Fabbri, Ondřej Mašek, Colin Logan Mackay, Marco Montalti, Andreas Hornung
Water-soluble organic compounds (WSOCs) were extracted from corn stalk biochar produced at increasing pyrolysis temperatures (350-650°C) and from the corresponding vapors, collected as bio-oil. WSOCs were characterized by gas chromatography (semi-volatile fraction), negative electron spray ionization high resolution mass spectrometry (hydrophilic fraction) and fluorescence spectroscopy. The pattern of semi-volatile WSOCs in bio-oil was dominated by aromatic products from lignocellulose, while in biochar was featured by saturated carboxylic acids from hemi/cellulose and lipids with concentrations decreased with decreasing H/C ratios...
April 24, 2017: Environmental Science & Technology
https://www.readbyqxmd.com/read/28431351/role-of-membrane-fouling-substances-on-the-rejection-of-n-nitrosamines-by-reverse-osmosis
#2
Takahiro Fujioka, Hitoshi Kodamatani, Hidenobu Aizawa, Stephen Gray, Kenneth P Ishida, Long D Nghiem
The impact of fouling substances on the rejection of four N-nitrosamines by a reverse osmosis (RO) membrane was evaluated by characterizing individual organic fractions in a secondary wastewater effluent and deploying a novel high-performance liquid chromatography-photochemical reaction-chemiluminescence (HPLC-PR-CL) analytical technique. The HPLC-PR-CL analytical technique allowed for a systematic examination of the correlation between the fouling level and the permeation of N-nitrosamines in the secondary wastewater effluent and synthetic wastewaters through an RO membrane...
April 3, 2017: Water Research
https://www.readbyqxmd.com/read/28424566/influence-of-organic-molecules-on-the-aggregation-of-tio2-nanoparticles-in-acidic-conditions
#3
Karin Danielsson, Julián A Gallego-Urrea, Martin Hassellov, Stefan Gustafsson, Caroline M Jonsson
Engineered nanoparticles released into the environment may interact with natural organic matter (NOM). Surface complexation affects the surface potential, which in turn may lead to aggregation of the particles. Aggregation of synthetic TiO2 (anatase) nanoparticles in aqueous suspension was investigated at pH 2.8 as a function of time in the presence of various organic molecules and Suwannee River fulvic acid (SRFA), using dynamic light scattering (DLS) and high-resolution transmission electron microscopy (TEM)...
2017: Journal of Nanoparticle Research: An Interdisciplinary Forum for Nanoscale Science and Technology
https://www.readbyqxmd.com/read/28407573/assessment-of-mobility-and-bioavailability-of-mercury-compounds-in-sewage-sludge-and-composts
#4
Beata Janowska, Kazimierz Szymański, Robert Sidełko, Izabela Siebielska, Bartosz Walendzik
Content of heavy metals, including mercury, determines the method of management and disposal of sewage sludge. Excessive concentration of mercury in composts used as organic fertilizer may lead to accumulation of this element in soil and plant material. Fractionation of mercury in sewage sludge and composts provides a better understanding of the extent of mobility and bioavailability of the different mercury species and helps in more informed decision making on the application of sludge for agricultural purposes...
April 10, 2017: Environmental Research
https://www.readbyqxmd.com/read/28402898/predicting-potential-release-of-dissolved-organic-matter-from-biochars-derived-from-agricultural-residues-using-fluorescence-and-ultraviolet-absorbance
#5
Ming Li, Afeng Zhang, Haiming Wu, Hai Liu, Jialong Lv
A combination of fluorescence excitation-emission (EEM) spectrophotometry with parallel factor analysis (PARAFAC) and UV-vis spectroscopy was used to assess dissolved organic matter (DOM) release by the wheat straw-derived biochar in various environmental conditions. The results showed that the concentration of dissolved organic carbon (DOC) extracted from the biochar ranged from 435 to 5000mgkg(-1), and the high DOM release would occur under the high temperature and alkaline environmental conditions. Four humic acid-like substances (C1, C2, C4 and C5), one fulvic acid-like substance (C3) and one tryptophan-like substance (C6) were identified by PARAFAC model...
March 31, 2017: Journal of Hazardous Materials
https://www.readbyqxmd.com/read/28391929/photodegradation-of-17%C3%AE-ethynylestradiol-in-dissolved-humic-substances-solution-kinetics-mechanism-and-estrogenicity-variation
#6
Dong Ren, Bin Huang, Dan Xiong, Huan He, Xiangqi Meng, Xuejun Pan
17α-Ethynylestradiol (EE2) in natural waters may cause adverse effects on organisms due to its high estrogenic potency. Laboratory studies were performed to study the effects of a local humic acid (LHA), fulvic acid (LFA) and Aldrich humic acid (AHA) on the photochemical behavior and estrogenic potency of EE2. Here photolytic experiments demonstrated that pure aqueous EE2 could undergo direct and self-sensitized photodegradation at a global rate of 0.0068hr(-1). Photodegradation rate of EE2 in 5.0mg/L dissolved humic substances (DHS) was determined to be 0...
April 2017: Journal of Environmental Sciences (China)
https://www.readbyqxmd.com/read/28368590/comparison-of-direct-and-indirect-photolysis-in-imazosulfuron-photodegradation
#7
Caitlin Rering, Katryn Williams, Matt Hengel, Ronald Tjeerdema
Imazosulfuron, a sulfonylurea herbicide used in rice cultivation, has been shown to undergo photodegradation in water, but neither the photochemical mechanism nor the role of indirect photolysis is known. The purpose of this study was to investigate the underlying processes that operate on imazosulfuron during aqueous photodegradation. Our data indicate that in the presence of oxygen, most photochemical degradation proceeds through a direct singlet-excited state pathway, whereas triplet-excited state imazosulfuron enhanced decay rates under low dissolved oxygen conditions...
April 7, 2017: Journal of Agricultural and Food Chemistry
https://www.readbyqxmd.com/read/28365074/ultraviolet-b-radiation-mobilizes-uranium-from-uranium-dissolved-organic-carbon-complexes-in-aquatic-systems-demonstrated-by-asymmetrical-flow-field-flow-fractionation
#8
Sachin Vilas Nehete, Terje Christensen, Brit Salbu, Hans-Christian Teien
Humic substances have a tendency to form complexes with metal ions in aquatic medium, impacting the metal mobility, decreasing bioavailability and toxicity. Ultraviolet-B (UV-B) radiation exposure degrades the humic substance, changes their molecular weight distribution and their metal binding capacity in aquatic medium. In this study, we experimented the effect of UV-B radiation on the uranium complexed with fulvic acids and humic acids in a soft water system at different pH, uranium concentrations and radiant exposure...
March 21, 2017: Journal of Chromatography. A
https://www.readbyqxmd.com/read/28361397/integration-of-coagulation-and-adsorption-for-removal-of-n-nitrosodimethylamine-ndma-precursors-from-biologically-treated-municipal-wastewater
#9
Miaomiao Wang, Yingjie Meng, Defang Ma, Yan Wang, Fengli Li, Xing Xu, Chufan Xia, Baoyu Gao
This study investigated the N-nitrosodimethylamine (NDMA) formation potential of various dissolved organic matter (DOM) fractions in biologically treated municipal wastewater by UF fractionation, XAD-8 resin adsorption isolation, and excitation and emission matrix (EEM) fluorescence spectroscopy. Removal of various NDMA precursor fractions was also analyzed to evaluate the efficiency of traditional water treatment processes (coagulation, adsorption, and coagulation-adsorption). Results showed that NDMA were mainly formed by low molecular weight (MW) fractions (<30 kDa) and hydrophilic fractions (HiS) in biologically treated municipal wastewater...
March 30, 2017: Environmental Science and Pollution Research International
https://www.readbyqxmd.com/read/28355587/exopolymeric-substances-from-drinking-water-biofilms-dynamics-of-production-and-relation-with-disinfection-by-products
#10
M F Lemus Pérez, M Rodríguez Susa
Exopolymeric substances (EPS) as an external matrix of biofilm could react with disinfectants in drinking water networks forming disinfection by-products (DBP). Based on an experimental setup using two chlorine conditions-biofilm 1 (2.6 ± 0.8 mgCl/L) and biofilm 2 (0.7 ± 0.2 mg Cl/L)-samples of biofilms were recovered during 9 campaigns and EPS were extracted. Analyses of SUVA, fluorescence and amino acid (AA) content were carried out on the EPS to observe variation over time and correlations with DBP formation potential (DBPfp) after chlorination...
June 1, 2017: Water Research
https://www.readbyqxmd.com/read/28333457/two-dimensional-offline-chromatographic-fractionation-for-the-characterization-of-humic-like-substances-in-atmospheric-aerosol-particles
#11
Tobias Spranger, Dominik van Pinxteren, Hartmut Herrmann
Organic carbon in atmospheric particles comprises a large fraction of chromatographically unresolved compounds, often referred to as humic-like substances (HULIS), which influence particle properties and impacts on climate, human health and ecosystems. To better understand its composition, a two-dimensional (2D) offline method combining size-exclusion (SEC) and reversed-phase liquid chromatography (RP-HPLC) using a new spiked gradient profile is presented. It separates HULIS into 55 fractions of different size and polarity, with estimated ranges of molecular weight and octanol/water partitioning coefficient (log P) from 160-900 g/mol and 0...
March 23, 2017: Environmental Science & Technology
https://www.readbyqxmd.com/read/28333435/laser-desorption-ionization-coupled-to-fticr-mass-spectrometry-for-studies-of-natural-organic-matter
#12
John W T Blackburn, Will Kew, Margaret C Graham, Dušan Uhrín
Laser desorption/ionization (LDI) was investigated as an ionization method for Fourier transform ion cyclotron resonance mass spectrometry (FTICR MS) studies of natural organic matter (NOM). Using International Humic Substances Society standards, Suwannee River fulvic acid (SRFA) and Suwannee River natural organic matter (SRNOM), LDI was found to ionize a very similar set of compounds (>90% of molecular formulas identity) to the matrix assisted laser desorption/ionization (MALDI), while producing higher quality spectra...
March 31, 2017: Analytical Chemistry
https://www.readbyqxmd.com/read/28324841/metal-mobilization-from-metallurgical-wastes-by-soil-organic-acids
#13
Anna Potysz, Malgorzata Grybos, Jakub Kierczak, Gilles Guibaud, Patrice Fondaneche, Piet N L Lens, Eric D van Hullebusch
Three types of Cu-slags differing in chemical and mineralogical composition (historical, shaft furnace, and granulated slags) and a matte from a lead recovery process were studied with respect to their susceptibility to release Cu, Zn and Pb upon exposure to organic acids commonly encountered in soil environments. Leaching experiments (24-960 h) were conducted with: i) humic acid (20 mg/L) at pH t0 = 4.4, ii) fulvic acid (20 mg/L) at pH t0 = 4.4, iii) an artificial root exudates (ARE) (17.4 g/L) solution at pH t0 = 4...
March 8, 2017: Chemosphere
https://www.readbyqxmd.com/read/28299570/occurrence-and-photodegradation-of-methylmercury-in-surface-water-of-wen-rui-tang-river-network-wenzhou-china
#14
Shuihong Pan, Chuchu Feng, Jialu Lin, Lidong Cheng, Chengjun Wang, Yuegang Zuo
The spatial distribution and seasonal variations of methylmercury (MeHg) in Wen-Rui-Tang (WRT) River network were investigated by monitoring the MeHg concentrations in surface water samples collected from 30 sites across the river network over four seasons. Detection frequencies and concentrations of MeHg were generally higher in January, indicating that low sunlight irradiation, wind speed, and temperature conditions might enhance the persistence of MeHg in surface water. The MeHg levels varied with sampling locations, with the highest concentrations being observed in the industrial area especially around wastewater outfall, revealing that the mercury contamination in WRT River mainly comes from the industrial wastewater...
March 16, 2017: Environmental Science and Pollution Research International
https://www.readbyqxmd.com/read/28290085/oxidation-of-indometacin-by-ferrate-vi-kinetics-degradation-pathways-and-toxicity-assessment
#15
Junlei Huang, Yahui Wang, Guoguang Liu, Ping Chen, Fengliang Wang, Jingshuai Ma, Fuhua Li, Haijin Liu, Wenying Lv
The oxidation of indometacin (IDM) by ferrate(VI) (Fe(VI)) was investigated to determine the reaction kinetics, transformation products, and changes in toxicity. The reaction between IDM and Fe(VI) followed first-order kinetics with respect to each reactant. The apparent second-order rate constants (k app) decreased from 9.35 to 6.52 M(-1) s(-1), as the pH of the solution increased from 7.0 to 10.0. The pH dependence of k app might be well explained by considering the species-specific rate constants of the reactions of IDM with Fe(VI)...
March 13, 2017: Environmental Science and Pollution Research International
https://www.readbyqxmd.com/read/28259581/potential-rainfall-intensity-and-ph-driven-shifts-in-the-apparent-fluorescent-composition-of-dissolved-organic-matter-in-rainwater
#16
Yongqiang Zhou, Xiaolong Yao, Yibo Zhang, Kun Shi, Yunlin Zhang, Erik Jeppesen, Guang Gao, Guangwei Zhu, Boqiang Qin
Perturbations of rainwater chromophoric dissolved organic matter (CDOM) fluorescence induced by changes in rainfall intensity and pH were investigated by field observations and laboratory pH titrations. Microbial humic-like fluorophores dominated the rainwater CDOM pool, followed by tryptophan-like and tyrosine-like substances. Increased rainfall intensity had notable dilution effects on all six fluorescent components (C1-C6) identified using parallel factor (PARAFAC) analysis, the effect being especially pronounced for the microbial humic-like C1, tryptophan-like C3, and tyrosine-like C5...
March 1, 2017: Environmental Pollution
https://www.readbyqxmd.com/read/28249210/elimination-of-microcystin-lr-and-residual-mn-species-using-permanganate-and-powdered-activated-carbon-oxidation-products-and-pathways
#17
Boyoung Jeong, Min-Seok Oh, Hyun-Mee Park, Chanhyuk Park, Eun-Ju Kim, Seok Won Hong
The oxidation of microcystin-LR (MC-LR) in deionized water (DI) and river water using potassium permanganate (KMnO4) at a neutral pH and at 23 ± 2 °C was investigated. These two aqueous systems (i.e., DI and river water) gave comparable second-order rate constants (289.9 and 285.5 M(-1)s(-1) (r(2) > 0.99), respectively), which confirmed the effectiveness of this oxidation process for the treatment of natural surface water. The presence of either humic or fulvic acid reduced the removal efficiency of MC-LR, with the latter exhibiting a greater inhibitory effect...
February 20, 2017: Water Research
https://www.readbyqxmd.com/read/28248517/determining-the-concentration-dependent-transformations-of-ag-nanoparticles-in-complex-media-using-sp-icp-ms-and-au-ag-core-shell-nanoparticles-as-tracers
#18
Ruth C Merrifield, Chady Stephan, Jamie Lead
The fate, behavior, and impact of engineered nanoparticles (NPs) in toxicological and environmental media are driven by complex processes which are difficult to quantify. A key limitation is the ability to perform measurements at low and environmentally relevant concentrations, since concentration may be a key factor determining fate and effects. Here, we use single particle inductively coupled mass spectroscopy (SP-ICP-MS) to measure directly NP diameter and particle number concentration of suspensions containing gold-silver core-shell (Au@Ag) NPs in EPA moderately hard water (MHW) and MHW containing 2...
March 1, 2017: Environmental Science & Technology
https://www.readbyqxmd.com/read/28244332/effect-of-fulvic-and-humic-acids-on-iron-and-manganese-homeostasis-in-rats
#19
József Szabó, András Valentin Vucskits, Erzsébet Berta, Emese Andrásofszky, András Bersényi, István Hullár
The objective of this study was to investigate the effects of fulvic acid (FA) and humic acid (HA) as the two main compounds of humic substances, separately on Fe and Mn homeostasis. Seventy-two male Wistar rats were randomly divided into 9 experimental groups. The control diet (AIN-93G formula) and diets supplemented with 0.1%, 0.2%, 0.4% and 0.8% HA or FA were fed for 26 days. Fe and Mn concentrations of the large intestinal content, liver, kidney, femur and hair were determined. No significant differences were observed in the production parameters...
March 2017: Acta Veterinaria Hungarica
https://www.readbyqxmd.com/read/28228360/earthworms-change-the-quantity-and-composition-of-dissolved-organic-carbon-and-reduce-greenhouse-gas-emissions-during-composting
#20
Abebe Nigussie, Sander Bruun, Andreas de Neergaard, Thomas W Kuyper
Dissolved organic carbon (DOC) has recently been proposed as an indicator of compost stability. We assessed the earthworms' effect on DOC content and composition during composting, and linked compost stability to greenhouse gas emissions and feeding ratio. Earthworms reduced total DOC content, indicating larger stability of vermicompost than of thermophilic compost. The concentrations of humic acid and fulvic acid were reduced by earthworms, whereas there was no significant effect on hydrophobic neutrals and hydrophilics...
February 19, 2017: Waste Management
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