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Fulvic acid

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...
June 11, 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 Hilario 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 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). For the first time, a chemical kinetics model was developed to explain behavior of Fe(II) and SRFA in SLF. Model and experimental results are used to find best-fit rate coefficients for key reactions...
June 5, 2017: Environmental Science & Technology
Morgane Derrien, Yun Kyung Lee, Jae-Eun Park, Penghui Li, Meilian Chen, Sang Hee Lee, Soo Hyung Lee, Jun-Bae Lee, Jin Hur
Optical properties and molecular composition of humic substances (HS) can provide valuable information on the sources and the history of the associated biogeochemical processes. In this study, many well-known spectral and molecular characteristics were examined in eight different HS samples, which were extracted from soils and sediments located in a forested watershed, via two advanced tools including fluorescence excitation emission matrix-parallel factor analysis (EEM-PARAFAC) and high-resolution Fourier transform ion cyclotron resonance mass spectrometry (FT-ICR MS)...
June 2, 2017: Environmental Science and Pollution Research International
Erkai He, Hao Qiu, Rongliang Qiu, Charlotte Rentenaar, Quentin Devresse, Cornelis A M Van Gestel
This study aimed at investigating the influence of different fractions of dissolved organic carbon (DOC) on the uptake and toxicity of nickel (Ni) in the soil invertebrate Enchytraeus crypticus after different exposure times. The addition of DOC as humic acid (HA) or fulvic acid (FA) significantly reduced Ni uptake by E. crypticus in the soil-solution test system. Median lethal effect concentrations were calculated based on total dissolved Ni concentrations (LC50[Ni]), free Ni ion activity (LC50{Ni(2+) }), and Ni body concentrations (LC50Body-Ni )...
June 2, 2017: Environmental Toxicology and Chemistry
D L Hughes, A Afsar, L M Harwood, T Jiang, D M Laventine, L J Shaw, M E Hodson
The ability of diethylenetriaminepentaacetic acid (DTPA)-functionalised, silica-coated magnetic nanoparticles to adsorb Pb and Zn from single and bi-metallic metal solutions and from solutions containing dissolved organic carbon was assessed. In all experiments 10 mL solutions containing 10 mg of nanoparticles were used. For single metal solutions (10 mg L(-1) Pb or Zn) at pH 2 to 8, extraction efficiencies were typically >70%. In bi-metallic experiments, examining the effect of a background of either Zn or Pb (0...
May 26, 2017: Chemosphere
Heng Dong, Keyi Zhang, Xiao Han, Bin Du, Qin Wei, Dong Wei
This study was carried out to evaluate achievement, performance and characteristics of microbial products in a partial nitrification sequencing batch reactor as a pretreatment for anaerobic ammonium oxidation (anammox). After 100 days long-term operation, the effluent NO2(-)-N/NH4(+)N ratio of the reactor was average at 1.3 and NO3(-)-N concentration was low by controlling low dissolved oxygen (DO) concentration, which was considered as the ideal influent for anammox. Specific oxygen uptake rate (SOUR) implied that (SOUR)NH4 and (SOUR)NO2 of ammonia oxidizing bacteria (AOB) and nitrite oxidizing bacteria (NOB) in sludge changed from 21...
May 20, 2017: Chemosphere
Mohamed Ateia, Onur G Apul, Yuta Shimizu, Astri Muflihah, Chihiro Yoshimura, Tanju Karanfil
Natural organic matter (NOM) is a heterogeneous mixture of organic compounds that is omnipresent in natural waters. To date, the understanding of the adsorption of NOM components by carbon nanotubes (CNTs) is limited because of the limited number of comprehensive studies in the literature examining the adsorption of NOM by CNTs. In this study, 11 standard NOM samples from various sources were characterized, and their adsorption behaviors on four different CNTs were examined side-by-side using total organic carbon, fluorescence, UV-visible spectroscopy, and high-performance size-exclusion chromatography (HPSEC) analysis...
June 5, 2017: Environmental Science & Technology
Ibrahim Abusallout, Guanghui Hua
Woodchip bioreactors are increasingly being applied to remove nitrate from agricultural subsurface drainage. However, dissolved organic carbon (DOC) released from woodchips may negatively affect the aquatic ecosystems and drinking water supplies. The objective of this study was to evaluate the leaching characteristics, disinfection byproduct (DBP) formation potentials, and treatability of DOC derived from a laboratory woodchip bioreactor. Initial flush of woodchips resulted in the release of high organic content from woodchips...
May 13, 2017: Chemosphere
Tao Lou, Xuejun Wang, Guojun Song, Guangpeng Cui
The flocculant made from natural polymers gained prominence in recent years due to its eco-friendliness and low cost. In this study, two natural polymers of chitosan and fulvic acid were successfully grafted with a synthetic monomer of acrylamide as a new type of flocculant. The prepared chitosan-acrylamide-fulvic acid (CAMFA) exhibited an excellent capacity to remove three typical dyes, the color removal ratios were 97.0%, 91.6%, and 38.2%, respectively, at the dosage of 283mg/L for 100mg/L of acid blue 113, reactive black 5 and methyl orange...
August 15, 2017: Carbohydrate Polymers
Shuqu Zhang, Longlu Wang, Chengbin Liu, Jinming Luo, John Crittenden, Xia Liu, Tao Cai, Jili Yuan, Yong Pei, Yutang Liu
It is attractive to photocatalytically purify wastewater and simultaneously convert solar energy into clean hydrogen energy. However, it is still a challenge owing to the relatively low photocatalytic efficiency of photocatalysts. In this study, we synthesized a molybdenum disulfide (MoS2) quantum dot-decorated 3D nanoarchitecture (MoS2QDs) of indium zinc sulfide (ZnIn2S4) and reduced grapheme oxide (MoS2QDs@ZnIn2S4@RGO) photocatalyst using a simple solvothermal method. The RGO promotes the electron transfer, and the highly dispersed MoS2QDs provides numerous catalytic sites...
May 10, 2017: Water Research
Rosa Francaviglia, Gianluca Renzi, Luigi Ledda, Anna Benedetti
Soil quality is mainly studied from the chemical and physical point of view, whereas soil biochemical and microbiological parameters are relatively more scarcely explored to assess the effect of management practices. This study aimed to evaluate soil organic carbon (SOC) and its pools; soil microbial activity parameters; and the Biological Fertility Index (BFI), in six land uses characteristics of the Mediterranean basin in north-eastern Sardinia. These land uses differed in management intensity and consisted of: tilled vineyard (TV), no tilled grassed vineyard (GV), former vineyards (FV), hay crop and pasture (HC and PA), cork oak forest (CO)...
December 1, 2017: Science of the Total Environment
Baowei Hu, Guohe Chen, Chengan Jin, Jun Hu, Chengcai Huang, Jiang Sheng, Guodong Sheng, Jingyuan Ma, Yuying Huang
Herein, a promising titanate nanotubes (TNT) anchored nanoscale zero-valent iron (NZVI) nanocomposite (NZVI/TNT) was synthesized, characterized and used for the enhanced scavenging of Cr(VI) and Se(VI) from water. The structural identification indicated that NZVI was uniformly loaded on TNT, thereby, the oxidation and aggregation of NZVI was significantly minimized. The macroscopic experimental results indicated that NZVI/TNT exhibited higher efficiency as well as rate on Cr(VI) and Se(VI) scavenging resulted from the good synergistic effect between adsorption and reduction...
April 28, 2017: Journal of Hazardous Materials
Patrick Riefer, Timm Klausmeyer, Burkhard Schmidt, Andreas Schäffer, Jan Schwarzbauer
The incorporation of xenobiotics into soil, especially via covalent bonds or sequestration has a major influence on the environmental behavior including toxicity, mobility, and bioavailability. The incorporation mode of 4-chloro-2-methylphenoxyacetic acid (MCPA) into organo-clay complexes has been investigated under a low (8.5 mg MCPA/kg soil) and high (1000 mg MCPA/kg soil) applied concentration, during an incubation period of up to 120 days. Emphasis was laid on the elucidation of distinct covalent linkages between non-extractable MCPA residues and humic sub-fractions (humic acids, fulvic acids, and humin)...
May 11, 2017: Journal of Environmental Science and Health. Part. B, Pesticides, Food Contaminants, and Agricultural Wastes
Rujun Yang, Han Su, Shenglu Qu, Xuchen Wang
The iron binding capacities (IBC) of fulvic acid (FA) and humic acid (HA) were determined in the salinity range from 5 to 40. The results indicated that IBC decreased while salinity increased. In addition, dissolved iron (dFe), FA and HA were also determined along the Yangtze River estuary's increasing salinity gradient from 0.14 to 33. The loss rates of dFe, FA and HA in the Yangtze River estuary were up to 96%, 74%, and 67%, respectively. The decreases in dFe, FA and HA, as well as the change in IBC of humic substances (HS) along the salinity gradient in the Yangtze River estuary were all well described by a first-order exponential attenuation model: y(dFe/FA/HA, S) = a0 × exp(kS) + y0...
May 3, 2017: Scientific Reports
Jos P M Vink, Andre van Zomeren, Joris J Dijkstra, Rob N J Comans
Simulating the storage of aerobic soils under water, the chemical speciation of heavy metals and arsenic was studied over a long-term reduction period. Time-dynamic and redox-discrete measurements in reactors were used to study geochemical changes. Large kinetic differences in the net-complexation quantities of heavy metals with sulfides was observed, and elevated pore water concentrations remained for a prolonged period (>1 year) specifically for As, B, Ba, Co, Mo, and Ni. Arsenic is associated to the iron phases as a co-precipitate or sorbed fraction to Fe-(hydr)oxides, and it is being released into solution as a consequence of the reduction of iron...
August 2017: Environmental Pollution
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