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Fulvic acid

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...
November 2016: 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...
October 7, 2016: Journal of Environmental Radioactivity
Liwen Qiang, Meng Chen, Ling-Yan Zhu, Wei Wu, Qiang Wang
As one of the most popular carbon-based nano-materials, graphene oxide (GO) has the potential to be released in aquatic environment and interact with some coexistent organic pollutants, such as perfluorooctane sulfonate (PFOS), which is an emerging persistent organic pollutant. In this study, the adsorption of PFOS on GO in presence of fulvic acid (FA), the impacts of GO and FA on PFOS toxicokinetics in carp (Cyprinus carpio), and in vitro digestion behaviors were examined. The results indicated that PFOS could be strongly adsorbed on GO with a Freundlich affinity coefficient KF of 580 ± 205 (mg/g)/(mg/L)n, while the adsorption was suppressed by FA due to competitive adsorption...
October 10, 2016: Environmental Science & Technology
Jun Hou, Yangyang Yang, Peifang Wang, Chao Wang, Lingzhan Miao, Xun Wang, Bowen Lv, Guoxiang You, Zhilin Liu
Extracellular polymeric substances (EPS) are key components of the cyanobacterium Microcystis aeruginosa and play an important role in cyanobacteria blooms formation. Here, we analyzed the effects of 48-h exposure to nanosized CeO2 (n-CeO2), CuO (n-CuO), and ZnO (n-ZnO) on the production and composition of EPS of M. aeruginosa. Toxicity experiments revealed that soluble nanoparticles (NPs) (n-ZnO, n-CuO) demonstrated higher toxicity to cells and caused membrane damage. The production of LB-EPS increased by 34...
October 5, 2016: Environmental Science and Pollution Research International
Yan Dang, Yuqing Lei, Zhao Liu, Yiting Xue, Dezhi Sun, Li-Ying Wang, Dawn E Holmes
A considerable amount of leachate with high fulvic acid (FA) content is generated during the municipal solid waste (MSW) incineration process. This incineration leachate is usually processed by downstream bio-methanogenic treatment. However, few studies have examined the impact that these compounds have on methanogenesis and how they are degraded and transformed during the treatment process. In this study, a laboratory-scale expanded granular sludge bed (EGSB) reactor was operated with MSW incineration leachate containing various concentrations of FA (1500 mg/L to 8000 mg/L) provided as the influent...
September 23, 2016: Water Research
Xiaolei Shi, Chunhua Xu, Hongying Hu, Fang Tang, Lijuan Sun
Meeting the regulatory discharge standards for pulp and paper mill wastewater has become ever more difficult because of its recalcitrant and colored dissolved organic matter (DOM). In this study, the variation of DOM from the secondary effluent of pulp and paper mill wastewater before and after coagulation was investigated based on hydrophobicity/hydrophilicity, apparent molecular weight (MW) and fluorescence. DOM fractions of the secondary effluent were all with the apparent MW <20 kDa. Particularly, the hydrophobic acids (HOA) fraction, mainly composed of humic-like materials, was the major component, and it also had the highest color and SUVA254 (UV254 to dissolved organic carbon ratio)...
September 2016: Water Science and Technology: a Journal of the International Association on Water Pollution Research
Meththika Vithanage, Hasintha Wijesekara, S S Mayakaduwa
Dissolved Organic Carbon (DOC) from landfill leachate may become potentially harmful when it combines with other organic or inorganic substances in wastewaters. Therefore, the aim of this study was to extract and analysis of DOC fractions in uncontrolled dumpsite at Gohagoda, Sri Lanka. Total organic carbon (TOC) and DOC in the leachate were measured. DOC fractions; humic acids (HA), fulvic acids (FA) and the hydrophilic fraction (Hyd) were isolated and purified with the resin techniques. Spectroscopic techniques and elemental analysis were performed to characterize isolated fractions of DOCs...
September 27, 2016: Environmental Technology
Ye Yuan, Peng Zhang, Andreas Schäffer, Burkhard Schmidt
As ultimate sink for xenobiotics released into the environment, sediments play an important role concerning the evaluation of the fate of foreign compounds. 3,4-Dichloroaniline (3,4-DCA) is a degradation product of herbicide propanil and some urea herbicides. Propanil was extensively used worldwide in rice cultivation. The aim of the study was to examine the fate of (14)C-labeled 3,4-DCA in a sediment-water system; the sediment was derived from a rice field in Northern Italy. After application of (14)C-3,4-DCA, a time-course study was performed using incubation periods from 4h to 56days...
September 23, 2016: Science of the Total Environment
Yi Zhang, Neil V Blough
A molecular probe, 3-amino-2,2,5,5,-tetramethy-1-pyrrolydinyloxy (3ap), was employed to determine the formation rates of one-electron reducing intermediates generated photochemically from both untreated and borohydride-reduced Suwanee River fulvic and humic acids (SRFA and SRHA, respectively). This stable nitroxyl radical reacts rapidly with reducing radicals and other one-electron reductants to produce a relatively stable product, the hydroxylamine, which can be derivatized with fluorescamine, separated by HPLC and quantified fluorimetrically...
October 6, 2016: Environmental Science & Technology
John M Pettibone, Jingyu Liu
To probe the transformation pathways of metallic nanomaterials, measurement tools capable of detecting and characterizing the broad distribution of products with limited perturbation are required. Here, we demonstrate the detection of transformation products resulting from 40 kDa PVP-coated silver nanoparticles (AgNPs) reacted in aerated, sulfide-containing water and EPA moderately hard reconstituted water standard. Using single particle inductively coupled plasma mass spectrometry, silver mass preservation in primary AgNP populations during sulfidation was observed under all reaction conditions examined...
October 4, 2016: Environmental Science & Technology
Kai Li, Dong Wei, Tao Yan, Bin Du, Qin Wei
The objective of this study was to evaluate the responses of soluble microbial products (SMP) and extracellular polymeric substances (EPS) to the presence of toxic 2,6-dichlorophenol (2,6-DCP) in aerobic granular sludge (AGS) system. Batch experiment showed that NH4(+)-N removal efficiency significantly decreased from 99.6% to 47.2% in the toxic 2,6-DCP of 20 mg/L. Moreover, the inhibition degrees of 2,6-DCP on (SOUR)H, [Formula: see text] and [Formula: see text] were 7.8%, 32.1% and 9.5%, respectively. The main components of SMP, including protein (PN) and polysaccharide (PS) increased from 2...
December 1, 2016: Journal of Environmental Management
Songwen Tan, Weiguo Li
This paper presents an experimental study on behaviour of fouling-related components during saline wastewater treatments in an enhanced mesoporous membrane bioreactor (MBR) system integrated with a biological contact oxidation reactor (BCOR). By monitoring the transmembrane pressure, the MBR system without BCOR assistance was observed to get membrane fouling easier during saline wastewater treatments. Typically, the concentration of total EPS gradually increased in the MBR system over the operation time, while no significant change in its concentration was observed in the BCOR-MBR system...
November 2016: Bioresource Technology
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