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Fulvic acid

Yaling Su, En Hu, Muhua Feng, Yongdong Zhang, Feizhou Chen, Zhengwen Liu
Terrestrial chromophoric dissolved organic matter (CDOM) could subsidize lake food webs. Trophic state and altitude have a pronounced influence on the CDOM concentration and composition of a lake. The impact of future changes in solar radiation on high-altitude lakes is particularly alarming because these aquatic ecosystems experience the most pronounced radiation variation worldwide. Photodegradation experiments were conducted on terrestrial CDOM samples from oligotrophic alpine Lake Tiancai and low-altitude eutrophic Lake Xiaohu to investigate the response of bacterial growth to photodegraded CDOM...
November 30, 2016: Science of the Total Environment
Elissandro S Emídio, Vânia Calisto, Mary Rosa R de Marchi, Valdemar I Esteves
The presence of estrogenic mycotoxins, such as zearalenone (ZEN), in surface waters is an emerging environmental issue. Little is known about its phototransformation behavior, which may influence its environmental fate. In this context, the phototransformation of ZEN was investigated in pure water, river water and estuarine water using simulated sunlight irradiation. Kinetic studies revealed that two concomitant processes contribute to the fate of ZEN under solar irradiation: photoisomerization and photodegradation...
November 18, 2016: Chemosphere
Huimin Qiu, Jinju Geng, Hongqiang Ren, Lili Ding, Ke Xu, Yan Zhang
The phototransformation of phosphite (HPO3(2-), H2PO3(-), +3) from Lake Taihu water (THW) under natural sunlight was evaluated. No direct phosphite photoreaction was observed under sunlight. Suspended solids were shown to play important roles in the indirect photoreaction of phosphite in lake water. The phototransformation of phosphite followed pseudo-first-order reaction kinetics and the kinetics constants (k, d(-1)) decreased as: 0.0324 (original THW), 0.0236 (sterilized THW), 0.0109 (filtered THW) and 0...
November 8, 2016: Water Research
Dan Cai, Xiuhong Yang, Shizhong Wang, Yuanqing Chao, J L Morel, Rongliang Qiu
Dissolved organic matter (DOM) released from forest leaf litter is potentially effective for the degradation of polycyclic aromatic hydrocarbons (PAHs), yet the inherent mechanism remains insufficiently elucidated. In this study, we investigated the effects of DOM derived from Pinus elliottii and Schima superba leaf litter on the degradation of phenanthrene by the phenanthrene degrading bacterium Sphingobium sp. Phe-1. DOM from different origins and at a large range of concentrations enhanced the degradation rate of phenanthrene...
November 9, 2016: Journal of Hazardous Materials
Mukesh Kumar Awasthi, Meijing Wang, Hongyu Chen, Quan Wang, Junchao Zhao, Xiuna Ren, Dong-Sheng Li, Sanjeev Kumar Awasthi, Feng Shen, Ronghua Li, Zengqiang Zhang
This study was performed to investigate the effects of biochar as an amendment to a gaseous emissions and sewage sludge (SS) composting dynamics. Six dosage of biochar [low dosage of biochar (LDB) - 2%, 4% and 6%; and higher dosage of biochar (HDB) - 8%, 12% and 18%] were amended to a mixture of SS and wheat straw (4:1 ratio on dry weight basis) and compared to control or without additive. The HDB significantly reduced CH4, N2O and NH3 emission by 92.85-95.34%, 95.14-97.30% and 58.03-65.17%, but not the CO2 emission...
November 5, 2016: Bioresource Technology
Fulan Li, Huaming Guo, Xiaoqian Zhou, Kai Zhao, Jiaxing Shen, Fei Liu, Chao Wei
High arsenic (As) groundwater usually has high concentrations of natural organic matter (NOM). Effects of NOM on arsenic adsorption were investigated to evaluate the efficiency of modified granular natural siderite (MGNS) as an adsorbent for groundwater arsenic remediation. Humic and fulvic acids (HA/FA) were selected as model NOM compounds. In batch tests, HA or FA was either first adsorbed onto the MGNS, or applied together with dissolved arsenic to investigate effects of both adsorbed and dissolved NOM on arsenic removal...
November 5, 2016: Chemosphere
Oumar Dia, Patrick Drogui, Gerardo Buelna, Rino Dubé, Ben Salah Ihsen
Electrocoagulation (EC) was employed to treat residual organic matter from a landfill leachate pretreated by an aerated bio-filter system. Organic matter (humic acids (HA), fulvic acids (FA) and hydrophilic compounds (Hyl)) was fractionated using DAX-8 resin in order to estimate the efficiency of EC on each fraction. Initial characterization of the bio-filtrated landfill leachate showed that humic substances (HA + FA) represented nearly 90% of TOC. The effects of current densities, type of anode (Aluminum versus iron), and treatment time on the performance of COD removal were investigated...
November 4, 2016: Chemosphere
Karsten E Braun, Ann-Katrin Luks, Burkhard Schmidt
The fate of (14)C-labeled herbicide prosulfocarb was studied in an agricultural soil and in a sediment-water system, the sediment part of which was derived from Yangtze Three Gorges Reservoir, China. Time-course studies were performed for 28 d and 49 d, respectively. Main transformation routes of (14)C-prosulfocarb were mineralization to (14)CO2 and formation of nonextractable residues amounting to 12.13% and 10.43%, respectively, after 28 days (soil), and 9.40% and 11.98%, respectively, after 49 d (sediment-water system)...
November 7, 2016: Journal of Environmental Science and Health. Part. B, Pesticides, Food Contaminants, and Agricultural Wastes
Jisheng Xu, Bingzi Zhao, Wenying Chu, Jingdong Mao, Jiabao Zhang
Knowledge of the structural features of humic substances (HSs) is essential for elucidating the mechanisms of humification in different soil environments and realizing their profound roles in environmental issues. The aim of this work was to investigate the chemical structures of fulvic acid (FA), humic acid (HA) and humin (HM) fractions isolated from an upland soil (Fluvisol) and a paddy soil (Anthrosol) typical in China using advanced solid-state (13)C nuclear magnetic resonance (NMR) techniques. The results revealed that there were great structural differences of HSs between the two soils...
October 25, 2016: Science of the Total Environment
Zhe Yang, Ying-Xue Sun, Tao Ye, Na Shi, Fang Tang, Hong-Ying Hu
Seawater reverse osmosis (SWRO) has been extensively applied to replenish the limited freshwater resources. One concern of such technology is the formation of disinfection by-products (DBPs) during the pre-chlorination process. For the SWRO tested in this study, the concentrations of trihalomethanes (THMs), haloacetic acids (HAAs), and haloacetonitriles (HANs) increased by 35.1, 23.7 and 4.9μg/L, respectively, after a seawater sample (with UV254/DOC of 3.7L/mg·m and Br(-) of 50.9mg/L) was pre-chlorinated (1-2mg-Cl2/L)...
October 25, 2016: Science of the Total Environment
Tânia F C V Silva, Petrick A Soares, Diego R Manenti, Amélia Fonseca, Isabel Saraiva, Rui A R Boaventura, Vítor J P Vilar
In this work, an innovative methodology for the treatment of landfill leachates, after aerobic lagooning, is proposed and adjusted at pilot-scale. This methodology involves an aerobic activated sludge biological pre-oxidation (ASBO), a coagulation/sedimentation step (240mgFe(3+)/L, at pH4.2) and a photo-oxidation through a photo-Fenton (PF) reaction (60mg Fe(2+), at pH2.8) combining solar and artificial light. The ASBO process applied to a leachate after aerobic lagooning, with high organic and nitrogen content (1...
October 22, 2016: Science of the Total Environment
Chenhao Gong, Gang Shen, Haiou Huang, Peiran He, Zhongguo Zhang, Baoqing Ma
Polycyclic aromatic hydrocarbons (PAHs) are an important class of water pollutants because of their known ecological and human toxicity. Electrocoagulation (EC) is a promising technology for mitigating industrial wastewater pollution, but the removal and transformation of PAHs during EC treatment has not yet been understood. Therefore, a paper-making wastewater effluent (PMWW) was employed in this study to investigate the relationship between PAHs' removal and transformation during EC treatment. The results show that 86% of PAHs were effectively removed not only by the electro-oxidation reactions, but also by adsorption onto Fe hydroxide flocs...
October 21, 2016: Chemosphere
Yuyang Long, Jing Xu, Dongsheng Shen, Yao Du, Huajun Feng
Leachate membrane concentrates containing high concentrations of organics and trace toxic compounds pose a major threat to the environment, and their treatment is an urgent issue. In this work, various coagulants were used to treat leachate membrane concentrates. Appropriate pH values for treatments with FeCl2, FeSO4, polyaluminum chloride, and FeCl3 were 3, 5, 5, and 4, respectively. FeCl3 achieved the highest total organic carbon (TOC) removal efficiency. The effect of the various anions in ferric coagulants [FeCl3, Fe2(SO4)3, and Fe(NO3)3] on the TOC removal efficiency was negligible...
October 17, 2016: Chemosphere
Yi Qin, Hui Zhu, Mi Zhang, Huifen Zhang, Cheng Xiang, Baocai Li
The chemical composition of fulvic acid (FA) with a molecular weight below 500 (FA-500) was analyzed, and its activity on promoting the seed germination of wheat was studied in this paper. The FA-500 was obtained by membrane separation technology and qualitatively and quantitatively analyzed by using gas chromatography-mass spectrometry combined with the retention index. Forty-seven constituents were identified, including structures with ester, acid and alcohol groups, which accounted for 95% of the total composition...
October 13, 2016: Molecules: a Journal of Synthetic Chemistry and Natural Product Chemistry
Chenyi Yuan, Mrinal Chakraborty, Silvio Canonica, Linda Kay Weavers, Christopher M Hadad, Yu-Ping Chin
Isoproturon (IPU) is a phenylurea herbicide used to control broad-leaf grasses on grain fields. Photosensitized transformation induced by excited triplet states of dissolved organic matter (3DOM*) has been identified as an important degradation pathway for IPU in sunlit waters, but the reappearance of IPU in the absence of light is observed after the initial photolysis. In this study, we elucidate the kinetics of this photo-degradation and dark-reappearance cycling of IPU in the presence of DOM proxies (aromatic ketones and reference fulvic acids)...
October 14, 2016: Environmental Science & Technology
Jared B Shaw, Tzu-Yung Lin, Franklin E Leach, Aleksey V Tolmachev, Nikola Tolić, Errol W Robinson, David W Koppenaal, Ljiljana Paša-Tolić
We provide the initial performance evaluation of a 21 Tesla Fourier transform ion cyclotron resonance mass spectrometer operating at the Environmental Molecular Sciences Laboratory at the Pacific Northwest National Laboratory. The spectrometer constructed for the 21T system employs a commercial dual linear ion trap mass spectrometer coupled to a FTICR spectrometer designed and built in-house. Performance gains from moving to higher magnetic field strength are exemplified by the measurement of peptide isotopic fine structure, complex natural organic matter mixtures, and large proteins...
October 12, 2016: Journal of the American Society for Mass Spectrometry
Pingping Zhai, Xuan Chen, Wenbo Dong, Hongjing Li, Jean-Marc Chovelon
This study aimed to investigate the degradation of triclosan (TCS) in the presence of p-aminobenzoic acid (PABA) under simulated sunlight irradiation (λ ≥ 290 nm). The effect of PABA concentration, pH, dissolved organic matter (DOM), and DOM-hydrolytic Fe(III) species complexes on the photodegradation of TCS in the presence of PABA (TCS-PABA) was also studied. The photolysis of TCS-PABA obeyed pseudo-first-order kinetics well, and the degradation of TCS-PABA enhanced with increasing solution pH (from 3...
October 13, 2016: Environmental Science and Pollution Research International
Hyeonyong Chung, Won Jung Ju, Eun Hea Jho, Kyoungphile Nam
Two-chamber microbial fuel cells (MFCs) were used to study the applicability of MFCs for hexavalent chromium (Cr(VI)) detection in water. The microbial acetate oxidation in the anode and the Cr(VI) reduction in the cathode together generated voltages, which were used to indicate the change in Cr(VI) concentrations of the cathode under varying conditions of pH, ionic strength, co-existing Fe(II) concentration, and organic matter concentration. The MFC-based Cr(VI) detector showed a significant change in voltage with increasing Cr(VI) concentration at pH 1 and 2, but not at higher pH conditions...
December 0: Environmental Monitoring and Assessment
Taylor A Brown, Benjamin A Jackson, Benjamin J Bythell, Alexandra C Stenson
The belief that chromatographic separation of complex environmental mixtures or natural organic matter (NOM) produces featureless humps from which little, if anything, can be learned is still pervasive. Meanwhile improvements in chromatography and the use of information-rich detection methods have led to meaningful fractionation and revealed consistent data. Here, we build on this work and developed a robust, facile two-dimensional separation with high orthogonality between dimensions. We illustrate that re-injections of fractions (both in the first and in the second dimension) leads to individual peaks at the expected retention times and use information-rich detection to investigate the basis on which NOM is fractionated...
October 5, 2016: Journal of Chromatography. A
Hilary P Emerson, Katherine A Hickok, Brian A Powell
Previous field experiments have suggested colloid-facilitated transport via inorganic and organic colloids as the primary mechanism of enhanced actinide transport in the subsurface at former nuclear weapons facilities. In this work, research was guided by the hypothesis that humic substances can enhance tetravalent actinide (An(IV)) migration by coating and mobilizing natural colloids in environmental systems and increasing An(IV) sorption to colloids. This mechanism is expected to occur under relatively acidic conditions where organic matter can sorb and coat colloid surfaces and facilitate formation of ternary colloid-ligand-actinide complexes...
December 2016: Journal of Environmental Radioactivity
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