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Fulvic acid

Shui-Wen Chang Chien, Shou-Hung Chen, Chi-Jui Li
Various properties of soil affect the partition of organic contaminants within, and conversely, the properties of the organic contaminants also directly affect their partition behavior in soil. Therefore, understanding the effects of various properties of soil on the partition of organic contaminants favors subsequent assessment and provides soil remediation methods for policymakers. This study selected pentachlorophenol (PCP), a common hydrophobic ionizable organic compound in contaminated sites worldwide, as the target contaminant...
August 12, 2017: Environmental Science and Pollution Research International
Chao Jiang, Shikha Garg, T David Waite
The effects of calcium on iron redox transformations in acidic non-irradiated and irradiated Suwannee River Fulvic Acid (SRFA) solutions are investigated in this study. Our results reveal that, even though calcium is redox-inert, it affects the redox transformations of iron with increased Fe(III) reduction rates under irradiated conditions and decreased Fe(II) oxidation rates in the dark in the presence compared to the absence of calcium. While the exact mechanism via which the Fe(III) reduction rate under irradiated conditions is impacted by calcium addition is not clear, the formation of more photo-labile weakly complexed Fe(III)SRFA is most consistent with our experimental results...
August 7, 2017: Environmental Science & Technology
Chunli Kang, Siqi Bao, Baiyan Chen, Yubo Zhong, Dongmei Huang, Yuhan Wang, Honghai Xue, Tao Tian
The photoconversion of 2-chloronaphthalene (CN-2) in water in a simulated sunlight system was investigated. The photoconversion efficiency, photoproducts and mechanisms were inspected, and the effects of inorganic ions (NO3(-), NO2(-)) and fulvic acid (FA) were discussed. The results showed that CN-2 could be transformed in water under the irradiation. NO3(-) and NO2(-) promoted the photoconversion of CN-2 owing to ·OH generated by the photolysis of NO3(-) and NO2(-); FA at a lower concentration promoted the photoconversion, but it had an inhibition effect at a higher concentration...
August 5, 2017: Bulletin of Environmental Contamination and Toxicology
Liangliang Wei, Xiaoyan An, Sheng Wang, Chonghua Xue, Junqiu Jiang, Qingliang Zhao, Felix Tetteh Kabutey, Kun Wang
In this study, the transformation of the sludge-related extracellular polymeric substances (EPS) during mesophilic anaerobic digestion was characterized to assess the effect of hydraulic retention time (HRT) on reactor deterioration/restarting. Experimental HRT variations from 20 to 15 and 10d was implemented for deterioration, and from 10 to 20d for restarting. Long-term digestion at the lowest HRT (10d) resulted in significant accumulation of hydrolyzed hydrophobic materials and volatile fatty acids in the supernatants...
July 22, 2017: Bioresource Technology
Pinjing He, Qinfang Yu, Hua Zhang, Liming Shao, Fan Lü
The effects of humic acid (HA) and fulvic acid (FA) on Cu(2+) adsorption on biochar were investigated, with mechanisms confirmed by excitation-emission matrix spectroscopy, Fourier transform infrared spectroscopy, and scanning electron microscopy. HA loading enhanced Cu(2+) adsorption on biochar, with the maximum enhancement of 55.0% occurring at an HA loading of 100 mg-C/L. The adsorbed HA introduced many additional functional groups to biochar, thus enhancing Cu(2+) adsorption, which decreased at HA concentrations >100 mg-C/L due to self-association of HA at high loading concentrations...
August 2, 2017: Scientific Reports
Haohao Wu, Xingkai Xu, Weiguo Cheng, Pingqing Fu, Fayun Li
There are large amounts of dissolved organic matter (DOM) released into the soil during spring thaw, but its bioavailability and components are still unknown. The quantity, composition and stability of DOM in water extracts of forest soils during thaw were studied after two-month freezing with 9 levels of soil moisture ranging from 10% to 90% water-filled pore space (WFPS), by measuring soil carbon dioxide (CO2) flux, biodegradable dissolved organic carbon (BDOC) and nitrogen (BDON), ultraviolet absorbance and parallel factor analysis of fluorescence excitation-emission matrices...
July 25, 2017: Scientific Reports
Chunmei Li, Donghong Wang, Xiong Xu, Meijia Xu, Zijian Wang, Ruiyang Xiao
Dissolved organic matter (DOM) can affect the performance of water treatment processes and produce undesirable disinfection by-products during disinfection. Several studies have been undertaken on the structural characterization of DOM, but its fate during drinking water treatment processes is still not fully understood. In this work, the nontargeted screening method of comprehensive two-dimensional gas chromatography-quadrupole mass spectrometry (GC×GC-qMS) was used to reveal the detailed changes of different chemical classes of compounds in DOM during conventional and advanced drinking water treatment processes at three drinking water treatment plants in China...
July 21, 2017: Science of the Total Environment
Wenyu Tian, Zhen Yang, Xue Zhang, Weifang Ma, Jie Jiang
Humic substances (HS) are one of the most important parts of dissolved organic matter which are ubiquitous in environments playing an important role in many (bio)geochemical processes. In order to define the effects of environmental conditions on the biological transformation of compounds in the presence of HS, microbial reduction rates of ferrihydrite under different HS concentrations, environmental temperature, and pH values were determined. The results showed that increasing the concentration of standard humic substances (Pahokee peat standard humic acids (PPHA) or Pahokee peat standard fulvic acids (PPFA)) purchased from the International Humic Substances Society could compensate for the certain gap of reduction rates between low temperature (10 °C) and high temperature (35 °C)...
July 19, 2017: Environmental Science and Pollution Research International
Meijie Ren, Harald Horn, Fritz H Frimmel
The influence of ionic strengthen and dissolved organic matter (DOM) on the aggregation of TiO2 nanoparticles (NPs) in municipal effluent was investigated. The results demonstrated that DOM promoted the mobility of NPs in aquatic system by synergism between static repulsion and steric effect, while electrolytes were opposite by charge-neutralization. The physical-chemical characteristics of DOM played the major role on the mobility of NPs. Bovine serum albumin (BSA) showed the strongest enhancement on the mobility of TiO2 NPs...
July 11, 2017: Water Research
Manabu Fujii, Erika Otani
Reactive oxygen species (ROS) such as superoxide (O2(-)) and hydrogen peroxide (H2O2) can be photochemically generated in aerobic waters containing natural organic matters (NOM) such as humic substances (HS). To investigate the effect of NOM molecular composition on the kinetics and mechanism of ROS transformation, photochemical O2(-) generation and subsequent H2O2 production via catalyzed and uncatalyzed (bimolecular dismutation) O2(-) decay were examined in the presence of 14 types of HS (pH 8.0). By using chemiluminescence and colorimetric techniques, the photochemical O2(-) generation rate, quasi-steady-state O2(-) concentration, catalyzed and uncatalyzed O2(-) decay rates, and H2O2 production rate were found to vary significantly by factors of 72, 18, 14, 320, and 7...
July 9, 2017: Water Research
Yuefei Ji, Lu Wang, Mengdi Jiang, Yan Yang, Peizeng Yang, Junhe Lu, Corinne Ferronato, Jean-Marc Chovelon
Sulfaquinoxaline (SQX) is a coccidiostatic drug widely used in poultry and swine production and has been frequently detected in various environmental compartments such as surface water, groundwater, soils, and sediments. In the present study, degradation of SQX by ferrous ion-activated peroxymonosulfate oxidation process (Fe(II)/PMS), a promising in situ chemical oxidation (ISCO) technique, was systematically investigated. Experimental results showed that Fe(II)/PMS process appeared to be more efficient for SQX removal relative to Fe(II)/persulfate process (Fe(II)/PS)...
July 5, 2017: Environmental Science and Pollution Research International
Fanhao Song, Fengchang Wu, Fei Guo, Hao Wang, Weiying Feng, Min Zhou, Yanghui Deng, Yingchen Bai, Baoshan Xing, John P Giesy
In aquatic environments, pH can control environmental behaviors of fulvic acid (FA) via regulating hydrolysis of functional groups. Sub-fractions of FA, eluted using pyrophosphate buffers with initial pHs of 3.0 (FA3), 5.0 (FA5), 7.0 (FA7), 9.0 (FA9) and 13.0 (FA13), were used to explore interactions between the various, operationally defined, FA fractions and protons, by use of EEM-PARAFAC analysis. Splitting of peaks (FA3 and FA13), merging of peaks (FA7), disappearance of peaks (FA9 and FA13), and red/blue-shifting of peaks were observed during fluorescence titration...
June 24, 2017: Science of the Total Environment
Wenming Dong, Jiamin Wan, Tetsu K Tokunaga, Benjamin Gilbert, Kenneth H Williams
In order to understand the transport and humification processes of dissolved organic matter (DOM) within sediments of a semi-arid floodplain at Rifle, Colorado, fluorescence excitation-emission matrix (EEM) spectroscopy, humification index (HIX) and specific UV absorbance (SUVA) at 254nm were applied for characterizing depth and seasonal variations of DOM composition. Results revealed that late spring snowmelt leached relatively fresh DOM from plant residue and soil organic matter down into the deeper vadose zone (VZ)...
July 2017: Journal of Environmental Sciences (China)
Tianyu Zhang, Tao Wang, Yujuan Lu
The bioavailability and toxicity of zinc to aquatic life depend on dissolved organic matter (DOM), such as Suwannee River Fulvic Acid (SRFA), which plays an important role in the speciation of zinc. This study examined reactions of SRFA with zinc at different concentrations from pH 3.0 to 9.0, and competitive binding of calcium/magnesium and zinc to SRFA at pH 6.0, using in situ absorbance. Interactions of Zn(2+) with SRFA chromophores were evidenced by the emergence of features in Zn-differential spectra. Among all Zn(2+)-SRFA systems, dominant peaks, located at 235, 275 and 385 nm, and the highest intensity at 235 nm indicated the replacement of protons by the bound Zn(2+)...
June 22, 2017: Environmental Geochemistry and Health
Wenhao Wang, Min Chen, Laodong Guo, Wen-Xiong Wang
The Jiulong River estuary, located in the southeastern China, suffered from metal pollution due to industrial effluent releases. Mixing of effluent and estuarine water may have significantly affected the size distribution of trace metals and their environmental fate. In the present study, colloidal size distribution of organic matter and selected metals were quantified using asymmetric flow field-flow fractionation (AF4) and ICP-MS. We demonstrated a dominance of dissolved metals in the 1-10kDa fraction, and metals such as Cu, Zn, Ni, Co, Pb, Cd and Mn were mostly regulated by terrestrial fulvic acid...
June 19, 2017: Science of the Total Environment
Qiyuan Sun, Juan Jiang, Yuyi Zheng, Feifeng Wang, Chunshan Wu, Rong-Rong Xie
The distribution variation in chromophoric dissolved organic matter (CDOM) content in mid-latitude subtropical drinking water source reservoirs (MDWSRs) has great significance in the security of aquatic environments and human health. CDOM distribution is heavily influenced by biogeochemical processes and anthropogenic activity. However, little is known regarding the impact of component variation and phytoplankton growth on CDOM distribution variation in MDWSR. Therefore, samples were collected from a representative MDWSR (the Shanzai Reservoir) for analysis...
July 2017: Environmental Science and Pollution Research International
Chen Song, Xiaoling Liu, Yonghui Song, Ruixia Liu, Hongjie Gao, Lu Han, Jianfeng Peng
Elimination of black-stinking water contamination has been listed as an urgent task in the Water pollution prevention action plan promulgated by State Council of China. However, the key blackening and stinking pollutants and their sources are still unclear. In this study, water quality of a black-stinking urban river in Beijing, Dongsha River, was evaluated firstly; then the distribution of the blackening and stinking pollutants was investigated, and the key pollutants and their potential sources were identified; and finally, the health risk of those pollutants was assessed...
June 5, 2017: Journal of Environmental Management
Wei Wu, Guoqiang Shan, Qian Xiang, Yinqing Zhang, Shujun Yi, Lingyan Zhu
Large volume production and application of nano-TiO2 make it inevitably release to natural waters and its environmental behaviors would be affected by natural organic matters. In this study, the mechanisms of humic acid (HA) affecting the photocatalytic performance of nano-TiO2 were elucidated by using three HA fractions from the same source but with different polarities. Bulk HA was fractionated on a silica gel column to get three fractions with polarity increasing in the order of FA, FB and FC. FA was fulvic acid-like while FB and FC were humic acid-like...
May 11, 2017: Water Research
Linee Goswami, Anil Nath, Sweety Sutradhar, Satya Sundar Bhattacharya, Ajay Kalamdhad, Kowsalya Vellingiri, Ki-Hyun Kim
Utilization of different types of solid wastes through composting is important for environmental sustainability and restoring soil quality. Although drum composting is an efficient technology, the possibility of heavy metal contamination restricts its large-scale use. In this research, a field experiment was conducted to evaluate the impact of water hyacinth drum compost (DC) and traditional vermicompost (VC) on soil quality and crop growth in an agro-ecosystem cultivated intensively with tomato and cabbage as test crops...
June 2, 2017: Journal of Environmental Management
David H Gonzalez, Christopher K Cala, Qiaoyun Peng, Suzanne E Paulson
Oxidative stress mediated by reactive oxygen species (ROS) is a hypothesized mechanism for particulate-matter related health effects. Fe(II) is a key player in ROS formation in surrogate lung fluid (SLF) containing antioxidants. Humic-like substances (HULIS) in particulate matter such as biomass burning aerosol chelate Fe(II), but the effect on ROS formation in the presence of lung antioxidants is not known. We use Suwanee River Fulvic Acid (SRFA) as a surrogate for HULIS and investigate its effect on OH formation from Fe(II)...
June 20, 2017: Environmental Science & Technology
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