Read by QxMD icon Read

Fulvic acid

Wen Shi, Zanfang Jin, Shiyin Hu, Xiaoman Fang, Feili Li
This study evaluated the impact of dissolved organic matter (DOM) of varying molecule weights (MWs) on long-term exposure to Cu and Pb in Chlorella pyrenoidosa. Citric acid, fulvic acid, and humic acid, in the order of increasing MWs, were selected to represent DOM. The results showed that DOM with larger MWs had stronger inhibitory effects on the bioavailability of Cu to algae. However, the biosorption isotherm of Pb in the presence of DOM was different: as Pb equilibrium concentration increased, the biosorption capacity increased sharply to a maximum, then decreased...
February 2, 2017: Chemosphere
C Constantino, S D W Comber, M D Scrimshaw
The shift toward bioavailability-based standards for metals such as copper and zinc not only improves the ecological relevance of the standard but also introduces significant complexity into assessing compliance. This study examined differences in the copper and zinc complexation characteristics of effluents from a range of different sewage treatment works and in relation to so-called 'natural' samples. This information is essential to determine whether the inclusion of effluent-specific complexation characteristics within the regulatory framework could enhance the environmental relevance of compliance criteria...
February 7, 2017: Environmental Science and Pollution Research International
Hu Wu, Zhouzhou Liu, Aimin Li, Hu Yang
China is a major textile manufacturer in the world; as a result, large quantities of dyeing effluents are generated every year in the country. In this study, the performances of two cationic starch-based flocculants with different chain architectures, i.e., starch-graft-poly[(2-methacryloyloxyethyl) trimethyl ammonium chloride] (STC-g-PDMC) and starch-3-chloro-2-hydroxypropyl trimethyl ammonium chloride (STC-CTA), in flocculating dissolved organic matter (DOM) in dyeing secondary effluents were investigated and compared with that of polyaluminum chloride (PAC)...
January 24, 2017: Chemosphere
Bożena Czech
The carbon nanotubes (CNT) present in the wastewater subjected to treatment will possess altered physico-chemical properties. The changed properties will result in the unknown behavior of CNT in the environment after disposal; and it is expected to differ from their pristine analogues. In the present paper the effect of sorption of dissolved organic matter with fulvic acids (FA) as representatives onto UV and/or H2O2 treated CNT was tested. Both kinetics and mechanism of sorption was estimated. The chemical adsorption was a rate limiting step and a pseudo-second order kinetics described the sorption of FA onto UV and/or H2O2 treated CNT...
February 3, 2017: Environmental Research
Andrew Chapin Maizel, Christina K Remucal
The photochemical production of reactive species, such as triplet dissolved organic matter ((3)DOM) and singlet oxygen ((1)O2), contributes to the degradation of aquatic contaminants and is related to an array of DOM structural characteristics, notably molecular weight. In order to relate DOM molecular weight, optical properties, and reactive species production, Suwannee River (SRFA) and Pony Lake fulvic acid (PLFA) isolates are fractionated by sequential ultrafiltration and the resultant fractions are evaluated in terms of molecular composition and photochemical reactivity...
January 25, 2017: Environmental Science & Technology
Hua-Wei Wang, Xiao-Yue Li, Zhi-Peng Hao, Ying-Jie Sun, Ya-Nan Wang, Wei-Hua Li, Yiu Fai Tsang
In this study, the transformation of dissolved organic matter (DOM) in nanofiltration concentrated leachate during three ozone-based oxidation processes (i.e., O3, O3/H2O2 and O3/UV) was investigated. The transformation characteristics of DOM were evaluated by gel filtration chromatography (GFC), XAD-8 resin fractionation, excitation-emission matrix fluorescence spectroscopy (EEM) and Fourier transform infrared spectroscopy (FTIR). Compared with O3-alone process, the removal efficiencies of COD, TOC, and color were improved in O3-combined processes (i...
January 19, 2017: Journal of Environmental Management
Weiwei Li, Fenfen Zhang, Qi Ye, Dan Wu, Liying Wang, Yihua Yu, Bing Deng, Jinzhou Du
Fulvic acid (FA) plays a significant role in biogenic-elemental cycling in aquatic ecosystems which is highly dependent on their organic composition. In this study, the aquatic FA contents and binding properties during bloom and non-bloom periods in Taihu Lake were investigated by two-dimensional correlation spectroscopy Fourier transform infrared spectroscopy (2D-COS-FTIR), nuclear magnetic resonance (NMR) and elemental analysis. Compared with non-bloom FA, bloom FA was of lower nitrogen content and higher C/N ratio...
April 2017: Chemosphere
Judith Schellekens, Peter Buurman, Karsten Kalbitz, Andre van Zomeren, Pablo Vidal-Torrado, Chiara Cerli, Rob N J Comans
Insight in the molecular structure of humic acid (HA) and fulvic acid (FA) can contribute to identify relationships between their molecular properties, and further our quantitative abilities to model important organic matter functions such as metal complexation and association with mineral surfaces. Pyrolysis gas chromatography/mass spectrometry (Py-GC-MS) is used to compare the molecular composition of HA and FA. A systematic comparison was obtained by using samples from different environmental sources, including solid and aqueous samples from both natural and waste sources...
January 19, 2017: Environmental Science & Technology
Tao Lin, Bingwei Hou, Jian Wang, Yaqun Xu, Wei Chen
Dissolved organic matter (DOM), as a very fine colloidal suspension, could inevitably affect the transformation process of dissolved organic nitrogen (DON) in drinking water treatment. Tryptophan and tyrosine were used as representatives of DON to investigate the interactions between amino acids and fulvic-like components of fluorescent DOM using titration experiments. The fluorescence intensity decreased significantly with the increasing fulvic acid (FA) concentration, suggesting that FA could greatly quench the intrinsic fluorescence of amino acids such as tryptophan and tyrosine...
January 18, 2017: Environmental Science and Pollution Research International
Zhuo Zeng, Ping Zheng, Aqiang Ding, Meng Zhang, Ghulam Abbas, Wei Li
Swine wastewater is one of the most serious pollution sources, and it has attracted a great public concern in China. Anaerobic digestion technology is extensively used in swine wastewater treatment. However, the anaerobic digestion effluents are difficult to meet the discharge standard. The results from batch experiments showed that plenty of refractory organic matter remained in the effluents after mesophilic anaerobic digestion for 30 days. The effluent total COD (tCOD) and soluble COD (sCOD) were 483 and 324 mg/L, respectively, with the sCOD/tCOD ratio of 0...
January 13, 2017: Environmental Science and Pollution Research International
Yang Gao, Jie He, Zhuliu He, Zhiwei Li, Bo Zhao, Yi Mu, Jeong-Yeol Lee, Zhangjie Chu
A 60-day feeding trial was conducted to determine the effect of dietary fulvic acid supplements on intestinal digestive activity (enzymatic analysis), antioxidant activity, immune enzyme activity and microflora composition of juvenile loach (initial weight of 6.2 ± 0.1 g) reared in experimental aquaria. Five test diets containing 0, 0.5, 1.0, 1.5, and 2% fulvic acid were randomly assigned to three aquaria, respectively. Elevated growth performance including final weight, weight gain (WG), specific growth rate (SGR) and feed conversion ratio (FCR) was observed in loaches that were fed fulvic acid...
January 9, 2017: Fish & Shellfish Immunology
Xin Zhong, Chongwei Cui, Shuili Yu
Ozonation of fulvic acid (FA) can result in diverse intermediate oxidation by-products, significantly affecting disinfection by-product (DBP) formation following chlorination. The objective of this study was to provide insight into ozone reaction intermediates and reveal the possible formation pathway of DBPs from ozonation of FA due to the formation of intermediate oxidation by-products. Aldehydes, aromatic acids, short-chain acids, chloroform, and dichloroacetic acid were detected at various ozone dosage additions...
January 10, 2017: Environmental Science and Pollution Research International
Dong Ren, Bin Huang, Benqin Yang, Xuejun Pan, Dionysios D Dionysiou
Photodegradation is an important abiotic pathway transforming organic pollutants in natural waters. Humic substances (HS), including humic and fulvic acids, are capable of accelerating the photodegradation of steroid estrogens. However, how the photodegradtion of the emerging pollutants influenced by HS is not clear. Thus, we studied the roles and mechanisms of HS in inducing the photodegradation of 17α-ethynylestradiol (EE2). HS generally induces EE2 photodegradation through binding and reactive species generation...
January 3, 2017: Journal of Hazardous Materials
K Afshinnia, M Baalousha
The attachment efficiency (α) is an important parameter that can be used to characterize nanoparticle (NPs) aggregation behavior and has been a topic of discussion of several papers in the past few years. The importance of α is because it is one of the key parameters that can be used to model NP environmental fate and behavior. This study uses UV-vis and laser Doppler electrophoresis to monitor the aggregation behavior of citrate-coated silver nanoparticles (cit-AgNPs) induced by Na(+) and Ca(2+) as counter ions in the presence and absence of Suwannee River fulvic acid (SRFA) as a surrogate of natural organic matter and different concentrations of phosphate buffer (0-1mM)...
December 30, 2016: Science of the Total Environment
Raoqiong Che, Li Huang, Jun-Wei Xu, Peng Zhao, Tao Li, Huixian Ma, Xuya Yu
Fulvic acid (FA) triggers lipid accumulation in Monoraphidium sp. FXY-10, which can produce biofuels. Therefore, the metabolism shift and gene expression changes influenced by fulvic acid should be investigated. In this study, lipid and protein contents increased rapidly from 44.6% to 54.3% and from 31.4% to 39.7% under FA treatment, respectively. By contrast, carbohydrate content sharply declined from 49.5% to 32.5%. The correlation between lipid content and gene expression was also analyzed. Results revealed that accD, ME, and GPAT genes were significantly correlated with lipid accumulation...
March 2017: Bioresource Technology
Lixiao Ni, Lili Su, Shiyin Li, Peifang Wang, Dandan Li, Xiang Ye, Yi Li, Yong Li, Yiping Li, Chao Wang
This study examines the uptake of the heavy metal cadmium (Cd) by Microcystis aeruginosa (M. aeruginosa) in the presence of dissolved organic matter (DOM) from different origins. The DOM used in this study were extracted from soil, sediment taken from Meiliang Bay at Taihu Lake and from M. aeruginosa cultured in the laboratory. The three different DOM were characterized using UV-visible absorption spectroscopy and Fourier transform infrared (FTIR) spectroscopy. The excitation-emission matrix (EEM) fluorescence spectroscopy was used to characterize the interactions of DOM with Cd(2+) ...
January 2, 2017: Environmental Toxicology and Chemistry
Dong Qing Zhang, Chin Yee Eng, David C Stuckey, Yan Zhou
The effect of zinc oxide nanoparticles (ZnO NPs) on the performance of an anoxic-aerobic submerged membrane bioreactor (MBR), and the characterization of the soluble microbial products (SMPs) produced in the presence of ZnO NPs was evaluated. Continuous operation over 144 days showed that ZnO NPs at concentrations of 10 and 50 mg/L exerted a negative impact on chemical oxygen demand (COD) and nitrogen removal, although ZnO NPs were efficiently removed in the MBR (>92%). 10 and 50 mg/L ZnO NPs decreased COD removal substantially from 93...
December 21, 2016: Chemosphere
Mostafa Zahmatkesh, Henri Spanjers, Jules B van Lier
Humic substances (HS) comprise the major content of hardly or non-biodegradable organic matters in the industrial wastewaters. Although the application of fungi has been reported before as a novel and sustainable technology for the treatment of humics, yet most of the previous studies have been performed using synthetic wastewaters. This paper presents the results of fungal treatment of a real industrial wastewater, providing insight into the main mechanisms involved and clarifying some ambiguities and uncertainties in the previous reports...
December 26, 2016: Environmental Technology
Fu-Xiang Tian, Xiao-Jun Hu, Bin Xu, Tian-Yang Zhang, Yu-Qiong Gao
The photodegradation of IO3(-) at 254nm and the formation of iodinated trihalomethanes (I-THMs) during subsequent chlorination or chloramination in the presence of natural organic matter (NOM) were investigated in this study. The thermodynamically stable IO3(-) can be degraded by UV irradiation with pseudo-first order kinetics and the quantum yield was calculated as 0.0591moleinstein(-1). Solution pH posed no remarkable influence on the photolysis rate of IO3(-). The UV phototransformation of IO3(-) was evidenced by the determination of iodide (I(-)) and hypoiodous acid (HOI) in solution...
December 6, 2016: Journal of Hazardous Materials
Junting Liang, Xuanyu Wang, Luzhi Li, Shengmin Xu, Jiang Jiang, Lijun Wu, Guoping Zhao, Shaopeng Chen
With the expanding use of engineered nanoparticles (NPs), development of a high-throughput, sensitive method for evaluating NP safety is important. In this study, we developed cell-based biosensors to efficiently and conveniently monitor NP toxicity. The biosensor cells were obtained by transiently transfecting human cells with biosensor plasmids containing a mCherry gene regulated by an inducible promoter [an activator protein 1 (AP-1) promoter, an interleukin 8 (IL8) promoter, or a B cell translocation gene 2 (BTG2) promoter], with an enhanced green-fluorescent protein gene driven by the cytomegalovirus promoter as the internal control...
December 18, 2016: Chemosphere
Fetch more papers »
Fetching more papers... Fetching...
Read by QxMD. Sign in or create an account to discover new knowledge that matter to you.
Remove bar
Read by QxMD icon Read

Search Tips

Use Boolean operators: AND/OR

diabetic AND foot
diabetes OR diabetic

Exclude a word using the 'minus' sign

Virchow -triad

Use Parentheses

water AND (cup OR glass)

Add an asterisk (*) at end of a word to include word stems

Neuro* will search for Neurology, Neuroscientist, Neurological, and so on

Use quotes to search for an exact phrase

"primary prevention of cancer"
(heart or cardiac or cardio*) AND arrest -"American Heart Association"