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Sample records for bromates

  1. 21 CFR 172.730 - Potassium bromate.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Potassium bromate. 172.730 Section 172.730 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) FOOD FOR HUMAN... Specific Usage Additives § 172.730 Potassium bromate. The food additive potassium bromate may be...

  2. 21 CFR 137.205 - Bromated whole wheat flour.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 2 2010-04-01 2010-04-01 false Bromated whole wheat flour. 137.205 Section 137... Cereal Flours and Related Products § 137.205 Bromated whole wheat flour. Bromated whole wheat flour... of ingredients, prescribed for whole wheat flour by § 137.200, except that potassium bromate is...

  3. Drinking water toxicity study of the environmental contaminant--Bromate.

    Science.gov (United States)

    Dongmei, Liu; Zhiwei, Wang; Qi, Zhu; Fuyi, Cui; Yujuan, Shan; Xiaodong, Liu

    2015-12-01

    Bromate is a byproduct of water disinfection that is produced when waters contain bromide treated with ozone. To investigate the level of the toxicity of bromate and find the most sensitive indicators in a short time, a series of toxicological assessments were conducted including the acute toxicity, cumulative toxicity, genetic toxicity and subacute toxicity of bromate (using Potassium Bromate to represent bromate). The LD50 of orally administered Potassium Bromate was 215 mg/kg in Wistar rats and 464 mg/kg in ICR mice. The cumulative toxicity of Potassium Bromate was not obvious. The Ames test, mouse bone marrow cell micronucleus test and mouse sperm abnormality test did not indicate mutagenicity. The results of the subacute study did not exhibit significant differences in most of the parameters, except the white blood cell count, which was significantly decreased in male rats. In addition, Potassium Bromate influenced the albumin, creatinine, total cholesterol, triglycerides and glucose levels in male rats to various extents. A thorough analysis of the above tests clearly demonstrates that bromate has toxicity, not obvious cumulative toxicity and the white blood cell count can be used as an indicator to reflect the toxicity of bromate and investigate bromate's toxic mechanism.

  4. STUDIES INTO THE MECHANISMS OF POTASSIUM BROMATE INDUCED THYROID CARCINOGENESIS

    Science.gov (United States)

    Studies into the Mechanisms of Potassium Bromate Induced Thyroid Carcinogenesis. Potassium bromate (KBrO3) occurs in finished drinking water as a by-product of the ozonation disinfection process and has been found to induce thyroid follicular cell tumors in the rat after ...

  5. Manganese porphyrin sensor for the determination of bromate.

    Science.gov (United States)

    Sheen, Shanty; Jos, Theresa; Rajith, Leena; Kumar, Krishnapillai Girish

    2016-03-01

    The electro reductive behavior and determination of bromate on [5, 10, 15, 20-tetrakis (4-methoxyphenylporphyrinato] Manganese (III) chloride (TMOPPMn(III)Cl) modified Gold electrode(GE) was investigated by Square wave voltammetry (SWV). Bromate showed an irreversible reduction peak at -164 mV in 0.1 M pH 7 Na2SO4 solution. The cathodic peak of bromate showed a reduction in potential of 88 mV on modifying GE with a porphyrin film. The peak current varied linearly with concentration with a detection limit of 3.56 × 10(-9) M. The influence of pH, scan rate, supporting electrolyte and interferents on the reduction peak current of bromate were studied. The developed sensor was proposed for the determination of bromate in bread samples and compared with the standard method. PMID:27570281

  6. [Acute Toxic Effects of Bromate on Aquatic Organisms].

    Science.gov (United States)

    Wang, Zhi-wei; Liu, Dong-mei; Zhang, Wen-juan; Cui, Fu-yi

    2016-02-15

    Acute toxic effects of potassium bromate, sodium bromate and potassium bromide on luminescent bacteria, water flea, green alga and zebrafish were studied using standard toxic testing methods. The results showed that the pollutants had no effect on the luminous intensity of luminescent bacteria. The 96 h EC5. of potassium bromate on Scenedesmus obliquus was 738.18 mg x L(-1), 48 h EC50 on Daphnia magna and Moina was 154.01 mg x L(-1) was 161.80 mg x L(-1), while 48 h LC50 was 198 52 mg x L(-1), 175.68 mg x L(-1), and 96 h LC50 on zebrafish was 931.4 mg x L(-1). The 96 h EC50 of sodium bromate on Scenedesmus obliquus was 540.26 mg x L(-1), 48 h EC50 Daphnia magna and Moina was 127.90 mg x L(-1), 111.07 mg x L(-1), while 48 h LC50 was 161.80 mg x L(-1), 123.47 mg x L(-1), and 96 h LC50 on zebrafish was 1065.6 mg x L(-1). But the effects of potassium bromide on the above several kinds of aquatic organisms were far smaller than those of potassium bromate and sodium bromate. The toxic effects on test organisms were due to the impacts of bromate after the comparison of different pollutants, and the effects were more obvious with the increase of exposure time. The order of sensitivity to the toxic effects of bromate was Daphnia magna, Moina > Scenedesmus obliquus > zebrafish > Chlorella vulgaris, luminescent bacteria. PMID:27363170

  7. Reduction of Bromate Formation During Ozonation of Drinking Water

    DEFF Research Database (Denmark)

    Antoniou, Maria; Sichel, C.; Andre, K.;

    This study focused on the prevention of carcinogenic bromate formation during ozonation of tap water from the DTU university campus. To achieve this, different pre-treatments including pH-adjustment, ammonia addition and chlorine-ammonia addition, were tested. Formation of bromated was drasticall...... reduced by each pretreatment while the required ozone dose for 90% atrazine removal increased at different degree for each pre-treatment....

  8. A new electrochemical oscillatory system of bromate in alkaline solution

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    A new electrochemical oscillatory system of bromate in alkaline solution is reported. In PtBromate-Alkaline solution system, two different types of electrochemical oscillations (Type Ⅰ and Type Ⅱ) can be observed. Type Ⅰ appears before hydrogen evolution and Type Ⅱ involves periodic hydrogen evolution. Type Ⅰ relates to the adsorption/desorption of the hydrogen on platinum electrode, and Type Ⅱ with periodic oscillation stems from the coupling of electrochemical reactions (the reduction of bromate and evolution hydrogen reaction) with mass transfer (diffusion and convection). More over, under the right conditions, the two types appear in different oscillatory modes, for example,simple periodical mode and mixed one, etc,, Crossed cycle in the cyclic voltammograms, which is the basiccharacteristics for electrochemical oscillatory systems, has also been observed as expected.

  9. Bromate formation from bromide oxidation by the UV/persulfate process.

    Science.gov (United States)

    Fang, Jing-Yun; Shang, Chii

    2012-08-21

    Bromate formation from bromide oxidation by the UV/persulfate process was investigated, along with changes in pH, persulfate dosages, and bromide concentrations in ultrapure water and in bromide-spiked real water. In general, the bromate formation increased with increasing persulfate dosage and bromide concentration. The bromate formation was initiated and primarily driven by sulfate radicals (SO(4)(•-)) and involved the formation of hypobromous acid/hypobromite (HOBr/OBr(-)) as an intermediate and bromate as the final product. Under the test conditions, the rate of the first step driven by SO(4)(•-) is slower than that of the second step. Direct UV photolysis of HOBr/OBr(-) to form bromate and the photolysis of bromate are insignificant. The bromate formation was similar for pH 4-7 but decreased over 90% with increasing pH from 7 to above 9. Less bromate was formed in the real water sample than in ultrapure water, which was primarily attributable to the presence of natural organic matter that reacts with bromine atoms, HOBr/OBr(-) and SO(4)(•-). The extent of bromate formation and degradation of micropollutants are nevertheless coupled processes unless intermediate bromine species are consumed by NOM in real water. PMID:22831804

  10. MODELING CRYPTOSPORIDIUM PARVUM OOCYST INACTIVATION AND BROMATE IN A FLOW-THROUGH OZONE CONTACTOR TREATING NATURAL WATER

    Science.gov (United States)

    A reactive transport model was developed to simultaneously predict Cryptosporidium parvum oocyst inactivation and bromate formation during ozonation of natural water. A mechanistic model previously established to predict bromate formation in organic-free synthetic waters w...

  11. Determination of BROMATE AT PARTS-PER-TRILLION LEVELS BY GAS CHROMATOGRAPHY-MASS SPECTROMETRY WITH NEGATIVE CHEMICAL IONIZATION

    Science.gov (United States)

    The ozonation of bromide-containing source waters produces bromate as a class 2B carcinogenic disinfection by-product. The present work describes the determination of bromate by gas chromatography-negative chemical ionization mass spectrometry (GC-NCIMS) following a bromate react...

  12. Control of Bromate and THM Precursors Using Ozonation Combined System

    Institute of Scientific and Technical Information of China (English)

    SHU-GUANG XIE; DONG-WEN SHI; DONG-HUI WEN; RUI WANG; DAN-LI XI

    2007-01-01

    Objective To investigate the feasibility of reducing THM precursors and controlling bromate taste and odor in drinking water taken from the Yellow River by an ozonation combined system. Methods The appropriate ozone dosage was determined,and then the changes of TOC,UV254 and THM formation potential(THMFP)in the combined system were evaluated. Results One mg/L ozone could effectively remove taste and odor and meet the maximum allowable bromate level in drinking water.The pre-ozonation increased THMFP,but the conventional treatment system could effectively reduce the odor.The bio-ceramic filter could partly reduce CHCI3FP,but sometimes might increase CHCI2BrFP and CHCIBr2FP.The biological activated carbon(BAC)filter could effectively reduce CHCI3FP and CHCI2BrFP,but increase CHCIBr2FP.Compared with other filters.the fresh activated carbon(FAC)filter performed better in reducing THMFP and even reduced CHCIBrzFP.Conclusion The combined system can effectively reduce taste,odor,CHCI3FP,and CHCI2BrFP and also bring bromate under control.

  13. Bromate ion formation in dark chlorination and ultraviolet/chlorination processes for bromide-containing water

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    Bormate (BrO3-) is a carcinogenic chemical produced in ozonation or chlorination of bromide-containing water. Although its formation in seawater with or without sunlight has been previously investigated, the formation of bromate in dilute solutions,particularly raw water for water treatment plant, is unknown. In this article, the results of bench scale tests to measure the formation rates of bromate formation in dilute solutions, including de-ionized water and raw water from Yangtze River, were presented in dark chlorination and ultraviolet (UV)/chlorination processes. And the effects of initial pH, initial concentration of NaOCl, and UV light intensity on bromate formation in UV/chlorination of the diluted solutions were investigated. Detectable bromate was formed in dark chlorination of the two water samples with a relatively slow production rate. Under routine disinfecting conditions, the amount of formed bromate is not likely to exceed the national standards (10 μg/L). UV irradiation enhanced the decay of free chlorine, and,simultaneously, 6.6%-32% of Br- was oxidized to BrO3-. And the formation of bromate exhibited three stages: rapid stage, slow stage and plateau. Under the experimental conditions (pH = 4.41-11.07, CCl2= 1.23-4.50 mg/L), low pH and high chlorine concentration favored the generation of bromate. High light intensity promoted the production rate of bromate, but decreased its total generation amount due to acceleration of chlorine decomposition.

  14. Stirring and mixing effects on oscillations and inhomogeneities in the minimal bromate oscillator

    Science.gov (United States)

    Dutt, A. K.; Menzinger, M.

    1999-04-01

    Stirring and mixing effects on the oscillations and inhomogeneities in the bromate-bromide-cerous system (minimal bromate oscillator) have been investigated in a continuously fed stirred tank reactor (CSTR). A movable microelectrode is used to monitor the inhomogeneities inside the CSTR in an oscillating phase. The results are explained in terms of the theory of imperfect mixing.

  15. Pilot study on bromate reduction in ozonation of water with low carbonate alkalinities by carbon dioxide

    Institute of Scientific and Technical Information of China (English)

    Ji Li; Li Zou; Lulu Guo; Jialin Ji

    2011-01-01

    A pilot study was carried out to explore the application of carbon dioxide for pH depression in a bubble column and its ability to inhibit bromate formation for water with a low alkalinity.Results showed that in the absence of ammonia,CO2 was capable of reducing bromate 38.0%-65.4% with one-unit pH depression.CO2 caused a slightly lower bromate reduction (4.2%) than did H2SO4 when the pH was depressed to 7.4,and a more a pronounced lower reduction (8.8%) when the pH was depressed to 6.9.In the presence of 0.20mg/L-N ammonia,bromate was largely inhibited with 73.9% reduction.When the pH was depressed to 7.4,CO2 and H2SO4 showed an 11.3% and 23.5% bromate reduction respectively,demonstrating that the joint use of CO2 and ammonia might be a plausible strategy of blocking all three bromate formation pathways.CO2 could be applied through the aeration diffuser together with ozone gas,resulting in a similar bromate reduction compared with the premixing method through Venturi mixer.

  16. Bistability in an uncatalyzed bromate oscillator in a continuously fed stirred tank reactor

    Science.gov (United States)

    Dutt, Arun K.; Müller, S. C.

    1996-01-01

    Uncatalyzed gallic acid oscillating system has been investigated in a continuously fed stirred tank reactor (CSTR). In the [Bromate]0-[Bromide]0 concentration space, a region has been located where a bistability is observed between an oscillatory branch and a flow branch. To our knowledge this is the first evidence of bistability in an uncatalyzed bromate oscillator. Some observations have been explained in terms of the skeleton mechanism proposed in the past.

  17. Effects of ion-exchange treatment on bromate formation and oxidation efficiency during ozonation

    OpenAIRE

    Echigo, S.; Itoh, S.; Niwa, A

    2012-01-01

    Ion-exchange treatment is a promising technique for removing hydrophilic compounds during drinking water treatment. In this study, we applied several different ion exchangers (i.e., anion exchange resins and a hydrotalcite compound) to bromide removal to minimize bromate formation during ozonation. It was found that ion-exchange treatment affected ozone and hydroxyl radical concentration profiles as well as bromate ion concentration after ozonation. Selecting an appropriate ion exchanger is i...

  18. [Determination of trace bromate in drinking water by ion chromatography with suppressed conductivity detection].

    Science.gov (United States)

    Ying, Bo; Li, Shumin; Yue, Yinling; Xueli, E

    2006-05-01

    Bromate is a common disinfection by-product produced from the ozonation of source water containing bromide. An ion exchange chromatographic method with suppressed conductivity detection for the determination of trace bromate in drinking water was developed. The separation of the bromate in drinking water was achieved on a Metrosep A Supp 5 anion exchange column and a Metrosep A Supp 4/5 Guard column with a carbonate eluent. A new dual suppressed system, an MSM II chemical suppressor combined with a CO2 suppressor, was used to suppress the background conductivity, and to improve the detection limit of bromate. Ion chromatographic experiments were carried out by using a Metrosep A Supp 5 anion exchange column with a suppressed conductivity detector and an eluent of 3.2 mmoL/L Na2CO3-1.0 mmol/L NaHCO3 at a flow rate of 0.65 mL/min. This method had good linearity (r = 0.9999) in the range of 5-100 microg/L and high precision (relative standard deviation (RSD) water, pure water and mineral water were 96.1%-107%, and the detection limit for bromate was 0.50 microg/L. This method has a simple operation procedure, good separation results, high sensitivity and good repeatability. It can be used as a standard method for the determination of bromate in drinking water.

  19. Determination of bromate in drinking water by ultraperformance liquid chromatography-tandem mass spectrometry.

    Science.gov (United States)

    Alsohaimi, Ibrahim Hotan; Alothman, Zeid Abdullah; Khan, Mohammad Rizwan; Abdalla, Mohammad Abulhassan; Busquets, Rosa; Alomary, Ahmad Khodran

    2012-10-01

    Bromate is a byproduct formed as a result of disinfection of bromide-containing source water with ozone or hypochlorite. The International Agency for Research on Cancer has recognized bromate as a possible human carcinogen, thus it is essential to determine in drinking water. Present work highlights a development of sensitive and fast analytical method for bromate determination in drinking water by using ultraperformance liquid chromatography-tandem mass spectrometry. The quality parameters of the developed method were established, obtaining very low limit of detection (0.01 ng/mL), repeatability and reproducibility have been found to be less than 3% in terms of relative standard deviation when analyzing a bromate standard at 0.05 μg/mL with 0.4 min analysis time. Developed method was applied for the analysis of metropolitan and bottled water from Saudi Arabia; 22 samples have been analyzed. Bromate was detected in the metropolitan water samples (from desalinization source) at concentrations ranging between 3.43 and 75.04 ng/mL and in the bottled water samples at concentrations ranging between 2.07 and 21.90 ng/mL. Moreover, in comparison to established analytical methods such as liquid chromatography-tandem mass spectrometry, the proposed method was found to be very sensitive, selective and rapid for the routine analysis of bromate at low level in drinking water.

  20. A Comparison between Ion chromatography and Inductively Coupled Plasma for the Determination of Bromate in Certain Samples of Foodstuffs

    Directory of Open Access Journals (Sweden)

    Alanowd O. Mehder

    2015-06-01

    Full Text Available Ion chromatography (IC and inductively coupled plasma (ICP-MS both were applied for the determination of bromate in some food samples. Attempts were made to establish calibration curves, however in case of IC, an additional abnormal peak was found to overlap with the bromate peak. This renders IC to be unsuccessful in the determination of bromate compared to ICP-MS technique. ICP-MS was found to give accurate results; therefore, it was applied for the determination of bromate in different samples of food stuffs.

  1. Novel pre-treatments to control bromate formation during ozonation

    DEFF Research Database (Denmark)

    Antoniou, Maria; Sichel, Cosima; Andre, Klaus;

    2016-01-01

    is of high interest. This study tested improvements to conventional ozonation that reduce the formation of the oxidation-by-product bromate, while maintaining the effectiveness for removal emerging contaminants (atrazine). MnO4−, ClO2−, ClO2, ClO−, CH3COOO−, HSO5− or S2O8−2 with NH4+ were tested as pre......−-NH4+, ClO2−-NH4+ and ClO2-NH4+. MnO4−-NH4+ was the only pre-treatment that didn’t inhibit atrazine removal. When compared with the previously proposed Cl2/NH4+ pre-treatment, MnO4− + NH4+ was found as effective for preventing BrO3− formation, while atrazine removal was higher. In addition, MnO4− + NH...

  2. Bromate formation on the non-porous TiO2 photoanode in the photoelectrocatalytic system.

    Science.gov (United States)

    Selcuk, Huseyin; Sarikaya, Hasan Z; Bekbolet, Miray; Anderson, Marc A

    2006-02-01

    The increasing use of ozone in water disinfection processes has been the focus of considerable concern in regards to inorganic disinfection by product formation of bromate in waters containing bromide. Due to the public health risk caused by the presence of bromate as a suspected carcinogen, attention had been addressed to the conditions under which bromate is formed. In this study, photoanodic bromine generation and bromate (BrO(3)(-)) formation were investigated using a TiO(2) electrode in a photoelectrocatalytic (PEC) treatment process. The separation of anodic and cathodic reactions in the PEC system resulted in a pH decrease from 9.3 to 3.0 in the photoanode compartment and an increase to 11.0 in the cathode compartment. Under a photo-illumination intensity of 5.7 m W cm(-2) UV, a biasing potential of +1.0V vs SCE, a pH of 6.0 and at a NaBr concentration of 1.0 x 10(-2) M, active bromine formation increased over time with 2.4 x 10(-6) M min(-6) rate and reached a steady-state concentration of 1.44 x 10(-4) M in 60 min. Bromate formation was detected after a lag-period of 15 min and exhibited a continuous increasing trend with respect to irradiation time. No bromate formation was observed below pH 6.5 whereas an increasing bromate concentrations and pH up to pH=8.5 were noted.

  3. Room temperature phosphorimetric determination of bromate in flour based on energy transfer.

    Science.gov (United States)

    Menendez-Miranda, Mario; Fernandez-Argüelles, Maria T; Costa-Fernandez, Jose M; Pereiro, Rosario; Sanz-Medel, Alfredo

    2013-11-15

    Determination of bromate ions in contaminated flour samples by using a room temperature phosphorescence (RTP) optosensor is described. The optosensor is based on the non-radiative energy transfer from α-bromonaphthalene (a phosphorescent molecule insensitive to the presence of the analyte) acting as donor, to an energy acceptor bromate-sensitive molecule (trifluoperazine hydrochloride). The RTP emission of the selected donor greatly overlaps with the absorption spectrum of the acceptor, resulting in a decrease of the measured signal as the concentration of bromate ions increases. A simple and general procedure is proposed to carry out the incorporation of both the donor and acceptor molecules in an appropriate solid material (sensing phase) through the co-immobilization of the species in a sol-gel inorganic matrix. The optimum amounts of the sol-gel precursors, including silica precursors, type of catalysis, and concentrations of donor and acceptor molecules, have been evaluated in order to obtain the best analytical features of the proposed optosensor for bromate determination. The highly stable developed sensing phase shows a selective and reversible response towards bromate even in presence of dissolved oxygen (a well-known quencher of the RTP). The calibration graphs were linear up to 200 mg L(-1), with a detection limit for bromate dissolved in aqueous medium of 0.2 mg L(-1). Sample throughput of the proposed optosensor was about 18 measurements h(-1). Application of the developed sensing phase was successfully proved for the detection of bromate ions in commercial flours, obtaining good recoveries. PMID:24148398

  4. A simple yet effective chromogenic reagent for the rapid estimation of bromate and hypochlorite in drinking water.

    Science.gov (United States)

    Zhang, Jia; Yang, Xiurong

    2013-01-21

    We present a method for the rapid visible assay of bromate and hypochlorite in drinking water within 5 min. The assay utilizes a commercially common reagent and allows the determination of bromate and hypochlorite at several ppb levels with remarkably high selectivity over other ions.

  5. Measurement of bromate in bread by liquid chromatography with post-column flow reactor detection.

    Science.gov (United States)

    Himata, K; Noda, M; Ando, S; Yamada, Y

    2000-01-01

    This method is suitable for the determination of bromate residues in a variety of baked goods. The peer-verified method trial was performed on white bread, multigrain bread, and coffee cake spiked with known levels of potassium bromate. The analytical portion is extracted with deionized water to remove bromate from the bulk of the baked product. The aqueous extract is carried through a series of steps to remove co-extractives that would interfere with the liquid chromatography (LC) in the determinative step or hasten the deterioration of the LC column. The extract is filtered before passing it through a reversed-phase solid-phase extraction (SPE) column and a cation-exchange column in the silver form to remove lipids and chloride, respectively. Ultrafiltration is then used to remove proteins with molecular weights of >30,000 daltons. Finally, a cation-exchange column in the sodium form is used to remove silver ions from the extract. The determinative step uses LC with a reversed-phase column and an ion-pairing agent in the mobile phase. Detection is based on the post-column reaction of bromate with o-dianisidine to form an oxidation product that is quantitated spectrophotometrically at 450 nm. Overall agreement between the submitting and peer laboratories was quite good. For bromate levels of 10-52 ppb, overall mean recoveries were 76.9 and 78.8% for the submitting and peer laboratories, respectively. The standard deviations were higher for the results of the peer laboratory, probably because of the generally higher level of baseline noise present in the chromatograms. The results demonstrate that the method provides adequate accuracy with low-fat as well as high-fat foods. Bromate at levels as low as 5 ppb (ng/g) can be detected with the method. PMID:10772172

  6. Selenium dioxide catalysed oxidation of acetic acid hydrazide by bromate in aqueous hydrochloric acid medium

    Indian Academy of Sciences (India)

    R S Yalgudre; G S Gokavi

    2012-07-01

    Selenium dioxide catalysed acetic acid hydrazide oxidation by bromate was studied in hydrochloric acid medium. The order in oxidant concentration, substrate and catalyst were found to be unity. Increasing hydrogen ion concentration increases the rate of the reaction due to protonation equilibria of the oxidant. The mechanism of the reaction involves prior complex formation between the catalyst and substrate, hydrazide, followed by its oxidation by diprotonated bromate in a slow step. Acetic acid was found to be the oxidation product. Other kinetic data like effect of solvent polarity and ionic strength on the reaction support the proposed mechanism.

  7. Propagation failures, breathing fronts, and nonannihilation collisions in the ferroin-bromate-pyrocatechol system.

    Science.gov (United States)

    Harati, Mohammad; Wang, Jichang

    2009-06-01

    The emergence of propagating pulses was investigated with the photosensitive ferroin-bromate-pyrocatechol reaction in capillary tubes, in which various interesting spatiotemporal behaviors such as propagation failure, breathing fronts, and transitions between propagating pulses and fronts have been observed. Rather than a mutual annihilation, the collision of a propagating pulse and a growing front forces the front to recede gradually. A phase diagram in the pyrocatechol-bromate concentration space shows that the pulse instabilities take place throughout the conditions at which the system generates wave activities, suggesting that the presence of coupled autocatalytic feedbacks may facilitate the onset of pulse instabilities.

  8. Fe(II)–Al(III) layered double hydroxides prepared by ultrasound-assisted co-precipitation method for the reduction of bromate

    Energy Technology Data Exchange (ETDEWEB)

    Zhong, Yu [College of Environmental Science and Engineering, Hunan University, Changsha 410082 (China); Key Laboratory of Environmental Biology and Pollution Control, Hunan University, Ministry of Education, Changsha 410082 (China); Yang, Qi, E-mail: yangqi@hnu.edu.cn [College of Environmental Science and Engineering, Hunan University, Changsha 410082 (China); Key Laboratory of Environmental Biology and Pollution Control, Hunan University, Ministry of Education, Changsha 410082 (China); Luo, Kun; Wu, Xiuqiong [College of Environmental Science and Engineering, Hunan University, Changsha 410082 (China); Key Laboratory of Environmental Biology and Pollution Control, Hunan University, Ministry of Education, Changsha 410082 (China); Li, Xiaoming, E-mail: xmli@hnu.edu.cn [College of Environmental Science and Engineering, Hunan University, Changsha 410082 (China); Key Laboratory of Environmental Biology and Pollution Control, Hunan University, Ministry of Education, Changsha 410082 (China); Liu, Yang [College of Environmental Science and Engineering, Hunan University, Changsha 410082 (China); Urban and Rural Garbage Disposal Technology Research Center, Hunan Province, Changsha 410082 (China); Tang, Wangwang; Zeng, Guangming; Peng, Bo [College of Environmental Science and Engineering, Hunan University, Changsha 410082 (China); Key Laboratory of Environmental Biology and Pollution Control, Hunan University, Ministry of Education, Changsha 410082 (China)

    2013-04-15

    Highlights: ► Fe(II)–Al(III) LDHs were synthesized by ultrasound-assisted co-precipitation method. ► The Fe–Al (30 min) exhibited highly reduction reactivity on bromate. ► Pseudo-first-order model described the experimental data well. ► The mechanisms of bromate removal were proposed. -- Abstract: Bromate is recognized as an oxyhalide disinfection byproduct in drinking water. In this paper, Fe(II)–Al(III) layered double hydroxides (Fe–Al LDHs) prepared by the ultrasound-assisted co-precipitation method were used for the reduction of bromate in solution. The Fe–Al LDHs particles were characterized by X-ray diffractometer, scanning electron microscopy and thermogravimetry–differential scanning calorimetry. It was found that ultrasound irradiation assistance promoted the formation of the hydrotalcite-like phase and then improved the removal efficiency of bromate. In addition, the effects of solid-to-solution ratio, contact time, initial bromate concentration, initial pH, coexisting anions on the bromate removal were investigated. The results showed the bromate with an initial concentration of 1.56 μmol/L could be completely removed from solution by Fe–Al LDHs within 120 min. When the initial bromate concentration was 7.81 μmol/L, the Fe–Al LDHs with irradiation time of 30 min exhibited the optimum removal efficiency and the bromate removal capacity (q{sub e}) was 6.80 μmol/g. In addition, the appearance of sulfate and production of bromide were observed simultaneously in this process, which suggested that ion-exchange between sulfate and bromate, and the reduction of bromate to bromide by Fe{sup 2+} were the main mechanisms responsible for the bromate removal by Fe–Al LDHs.

  9. Conversion of organic micropollutants with limited bromate formation during the Peroxone process in drinking water treatment

    NARCIS (Netherlands)

    Knol, A.H.; Lekkerkerker-Teunissen, K.; Houtman, C.J.; Scheideler, J.; Ried, A.; Van Dijk, J.C.

    2015-01-01

    Advanced oxidation with O3 / H2O2 (peroxone) was conducted on pilot plant scale on pre-treated Meuse river water to investigate the conversion of organic micropollutants (OMPs) and the formation of bromate. Fourteen selected model compounds were dosed to the pre-treated river water on a regular basi

  10. CONSUMER WILLINGNESS TO PAY FOR SAFETY LABELS IN NIGERIA: A CASE STUDY OF POTASSIUM BROMATE IN BREAD

    Directory of Open Access Journals (Sweden)

    O Oni

    2006-05-01

    Full Text Available The study analysed consumer willingness to pay for safety labels in Nigeria by a case study of potassium bromate in bread” in Benin City, Edo State. It specifi cally investigates factors that promote willingness to pay for label among consumers of bread in Benin City, Edo State. Data used for the study were obtained through a well-structured questionnaire from 200 respondents. Both descriptive analytical methods and probit regression models were used for the analysis. The study revealed that 73% of the respondents are in their active working age with 50 percent of the respondent being male and female respectively. 67 percent of the respondents are married with 55 percent having an average of 5 members per household. 99 percent of the respondents are educated i.e. they have the capability of being able to read and write. Respondents purchased bread mainly from hawkers (60% with about 60% of them being aware of the presence of bromate in bread. 40% of the consumers used labeling as a way of identifying bromate free bread. Other methods reported deal with differences in price of bread with same weight, aroma and taste. Result also revealed that 60% of the respondents got to know about the negative effect of bromate from news (both print and mass media. Econometric results show that variables like education, gender, income, prior knowledge of bromate and perception held by respondents of negative implications of bromate signifi cantly infl uence the willingness to pay for safety labels. Education, gender, income and prior knowledge of bromate positively infl uence the probability of consumers’ decision to pay for safety label, while price of bread and confi dence and perception held by respondents of negative implications of bromate on human health infl uence consumers willingness to pay more for safety labels. The study, thus, suggests a defi ned market for bread purchases, community based awareness programme and extension of National Agency

  11. Fast and efficient benign oxidation of native wheat starch by acidic bromate under microwave activation.

    Science.gov (United States)

    Komulainen, Sanna; Diaz, Estibaliz; Pursiainen, Jouni; Lajunen, Marja

    2013-02-15

    A simple oxidation of starch in water by bromate was substantially improved by microwave activation. In the oxidation of native wheat starch its advantages were the highly reduced need of oxidant from 1.05 to 0.1-0.25 equiv, shortened reaction time from 2 to 5.5h to 10 min, and moderate or high yields of oxidation content (degree of oxidation 0.22-0.55) of water-soluble products. Acidic treatment before the oxidation reaction promoted the carbonyl formation yielding higher contents of oxidized products (degree of oxidation 0.43-0.55) than without it (degree of oxidation 0.22-0.28). The pretreatment did not have similar effect on the amount of carboxyl groups. The oxidation route of acidic bromate oxidation of starch is discussed.

  12. Cetyltrimethylammonium-coated magnetic nanoparticles for the extraction of bromate, followed by its spectrophotometric determination

    International Nuclear Information System (INIS)

    We report on a combination of magnetic solid-phase extraction and spectrophotometric determination of bromate. Cetyltrimethylammonium ion was adsorbed on the surface of phenyl-functionalized silica-coated Fe3O4 nanoparticles (Ph-SiO2-Fe3O4), and these materials served as the sorbent. The effects of surfactant and amount of sorbent, the composition of the desorption solution, the extraction time and temperature were optimized. Under optimized conditions, an enrichment factor of 12 was achieved, and the relative standard deviation is 2.9 % (for n = 5). The calibration plot covers the 1–50 ng mL−1 range with reasonable linearity (r2 > 0.998); and the limit of detection is 0.5 ng mL−1. The method is not interfered by ionic compounds commonly found in environmental water samples. It was successfully applied to the determination of bromate in spiked water samples. (author)

  13. Application of Silver and Silver Oxide Nanoparticles Impregnated on Activated Carbon to the Degradation of Bromate.

    Science.gov (United States)

    Choi, J S; Lee, H; Park, Y K; Kim, S J; Kim, B J; An, K H; Kim, B H; Jung, S C

    2016-05-01

    Silver and silver oxide nanoparticles were impregnated on the surface of powdered activated carbon (PAC) using a single-step liquid phase plasma (LPP) method. Spherical silver and silver oxide nanoparticles of 20 to 100 nm size were dipersed evenly on the surface of PAC. The impregnated PAC exhibited a higher activity for the decomposition of bromate than bare PAC. The XPS, Raman and EDX analyses showed that the Ag/PAC composites synthesized by the LPP process. PMID:27483780

  14. Ruthenium catalyst on carbon nanofiber support layers for use in silicon-based structured microreactors, Part II: Catalytic reduction of bromate contaminants in aqueous phase

    NARCIS (Netherlands)

    Thakur, D.B.; Tiggelaar, R.M.; Weber, Y.; Gardeniers, J.G.E.; Lefferts, L.; Seshan, K.

    2011-01-01

    Catalyst layers were synthesized inside a structured channel of silicon based microreactor and used to remove bromate contaminants in water. It is demonstrated that Ru/CNF based catalyst is active for bromate reduction, resulting in turn over frequencies (TOFs) higher than conventional powdered cata

  15. Conversion of organic micropollutants with limited bromate formation during the Peroxone process in drinking water treatment

    OpenAIRE

    Knol, A.H.; Lekkerkerker-Teunissen, K.; C. J. Houtman; Scheideler, J.; Ried, A.; Van Dijk, J. C.

    2015-01-01

    Advanced oxidation with O3/H2O2 (peroxone) is conducted on pilot plant scale on pre-treated Meuse river water to investigate the conversion of organic micropollutants (OMPs) and the formation of bromate. Fourteen selected model compounds are dosed to the pre-treated river water on a regular basis to assess the efficiency of the peroxone process and to establish the influence of the water matrix. The height of the ozone dose is the main factor in the conversion of t...

  16. Surface studies on as-grown (111) faces of sodium bromate crystals

    Indian Academy of Sciences (India)

    K Kishan Rao; V Surender

    2001-12-01

    Single crystals of sodium bromate are grown at various supersaturations ranging from 3% to 8%. Surface studies have been carried out on as-grown and etched (111) faces of these crystals. Typical and systematically oriented growth hillocks are observed almost on all the faces. Further dislocation studies are made to understand the growth history of these crystals. These studies suggest that the crystals grow by 2D-growth mechanism. In addition to this, studies are also conducted on the formation of overgrowths and inclusions in these crystals.

  17. Formation of bromate during ferrate(VI) oxidation of bromide in water.

    Science.gov (United States)

    Huang, Xin; Deng, Yang; Liu, Shuang; Song, Yali; Li, Nanzhu; Zhou, Jizhi

    2016-07-01

    Ferrate (VI) is traditionally recognized as a safe oxidant without production of disinfection byproducts (DBPs). However, here we detected probable carcinogenic bromate (BrO3(-)) during ferrate(VI) oxidation of bromide (Br(-))-containing water, and evaluated the effects of pH, ferrate(VI) dose, initial Br(-) concentration, and co-existing anions on the BrO3(-) formation. BrO3(-) was produced at a moderately-weakly acidic pH condition and in the absence of phosphate that was commonly applied as a buffer and stabilizing agent in previous ferrate(VI) studies. At pH 5.0, the produced BrO3(-) was increased from 12.5 to 273.8 μg/L with the increasing initial Br(-) concentration from 200 to 1000 μg/L at 10 mg/L Fe(VI), corresponding to an increase in the molar conversion ([BrO3(-)]/initial [Br(-)]) from 2.3% to 10.3%, in a bicarbonate-buffered solution. As pH increased to 7.0, the BrO3(-) concentration gradually dropped. The BrO3(-) production appeared to be associated with the oxidation by high valence iron species (i.e. Fe(VI), Fe(V) and Fe(IV)). Two key intermediate products (i.e. hypobromous acid/hypobromite (HOBr/OBr(-)) and hydrogen peroxide (H2O2)) relevant to the bromate formation were identified. The production of HOBr, a requisite intermediate for the ensuing bromate formation, was indirectly validated through identification of bromine-containing trihalomethanes and haloacetic acids during ferrate oxidation in a natural water, though these bromo-organic DBPs produced were insignificant. Furthermore, the inhibition effects of various anions on the formation of BrO3(-) followed chloride H2O2 was detected at higher phosphate concentration. It could reduce HOBr to Br(-), thereby inhibiting the bromate formation. PMID:27153235

  18. Chlorination of bromide-containing waters: Enhanced bromate formation in the presence ofsynthetic metal oxides and deposits formed indrinking water distribution systems

    KAUST Repository

    Liu, Chao

    2013-09-01

    Bromate formation from the reaction between chlorine and bromide in homogeneous solution is a slow process. The present study investigated metal oxides enhanced bromate formation during chlorination of bromide-containing waters. Selected metal oxides enhanced the decay of hypobromous acid (HOBr), a requisite intermediate during the oxidation of bromide to bromate, via (i) disproportionation to bromate in the presence of nickel oxide (NiO) and cupric oxide (CuO), (ii) oxidation of a metal to a higher valence state in the presence of cuprous oxide (Cu2O) and (iii) oxygen formation by NiO and CuO. Goethite (α-FeOOH) did not enhance either of these pathways. Non-charged species of metal oxides seem to be responsible for the catalytic disproportionation which shows its highest rate in the pH range near the pKa of HOBr. Due to the ability to catalyze HOBr disproportionation, bromate was formed during chlorination of bromide-containing waters in the presence of CuO and NiO, whereas no bromate was detected in the presence of Cu2O and α-FeOOH for analogous conditions. The inhibition ability of coexisting anions on bromate formation at pH 8.6 follows the sequence of phosphate>>sulfate>bicarbonate/carbonate. A black deposit in a water pipe harvested from a drinking water distribution system exerted significant residual oxidant decay and bromate formation during chlorination of bromide-containing waters. Energy dispersive spectroscopy (EDS) analyses showed that the black deposit contained copper (14%, atomic percentage) and nickel (1.8%, atomic percentage). Cupric oxide was further confirmed by X-ray diffraction (XRD). These results indicate that bromate formation may be of concern during chlorination of bromide-containing waters in distribution systems containing CuO and/or NiO. © 2013 Elsevier Ltd.

  19. Complex dynamic behavior in the bromate-oxalic acid-acetone-Mn(II) oscillating reaction in a continuous stirred tank reactor (CSTR)

    Science.gov (United States)

    Silva, Lucyane C.; Faria, Roberto B.

    2007-05-01

    The oscillating reaction bromate-oxalic acid-acetone-Mn(II)-sulfuric acid was observed for the first time in a CSTR at 20 °C. Depending on the bromate concentrations and flow rate, the system showed large amplitude oscillations, two kinds of mixed mode oscillations, quasiperiodicity and bursts of large amplitude oscillations, all mapped in a phase diagram. More complex behavior was favored at low bromate concentrations. The system without acetone was discovered to oscillate too, but the more complex patterns were not seen, indicating that acetone is implied in their formation.

  20. Ion Chromatographic Method with Post-Column Fuchsin Reaction for Measurement of Bromate in Chlorinated Water

    Directory of Open Access Journals (Sweden)

    Homer C. Genuino

    2009-06-01

    Full Text Available An ion chromatographic method that employs a post-column reaction with fuchsin and spectrophotometric detection was optimized for measuring bromate (BrO3- in water. BrO3- is converted to Br2 by sodium metabisulfite and then reacted with acidic fuchsin to form a red-colored product that strongly absorbs at 530 nm. The reaction of BrO3- and fuchsin reagent is optimum at pH 3.5 and 65 oC. The method has a limit of quantitation of 4.5 µg L-1 and is linear up to 150 µg L-1 BrO3-. Recoveries from spiked samples were high ranging from 95 to 102 % using external standard calibration and 87 to 103 % using standard addition method. Intra-batch and inter-batch reproducibility studies of the method resulted to RSD values ranging from 0.62 to 2.01 % and percent relative error of 0.12 to 2.94 % for BrO3- concentrations of 10 µg L-1 and 50 µg L-1. This method is free of interferences from common inorganic anions at levels typically found in chlorinated tap drinking water without preconcentration. The optimized method can be applied to trace analysis of bromate in chlorinated tap drinking water samples.

  1. Determination of bromate in drinking water by zone electrophoresis-isotachophoresis on a column-coupling chip with conductivity detection.

    Science.gov (United States)

    Bodor, Róbert; Kaniansky, Dusan; Masár, Marián; Silleová, Katarína; Stanislawski, Bernd

    2002-10-01

    The use of capillary zone electrophoresis (CZE) on-line coupled with isotachophoresis (ITP) sample pretreatment (ITP-CZE) on a poly(methylmethacrylate) chip, provided with two separation channels in the column-coupling (CC) arrangement and on-column conductivity detection sensors, to the determination of bromate in drinking water was investigated. Hydrodynamic and electroosmotic flows of the solution in the separation compartment of the chip were suppressed and electrophoresis was a dominant transport process in the ITP-CZE separations. A high sample load capacity, linked with the use of ITP in this combination, made possible loading of the samples by a 9.2 microL sample injection channel of the chip. In addition, bromate was concentrated by a factor of 10(3) or more in the ITP stage of the separation and, therefore, its transfer to the CZE stage characterized negligible injection dispersion. This, along with a favorable electric conductivity of the carrier electrolyte solution, contributed to a 20 nmol/L (2.5 ppb) limit of detection for bromate in the CZE stage. Sample cleanup, integrated into the ITP stage, effectively complemented such a detection sensitivity and bromate could be quantified in drinking water matrices when its concentration was 80 nmol/L (10 ppb) or slightly less while the concentrations of anionic macroconstituent (chloride, sulfate, nitrate) in the loaded sample corresponding to a 2 mmol/L (70 ppm) concentration of chloride were still tolerable. The samples containing macroconstituents at higher concentrations required appropriate dilutions and, consequently, bromate in these samples could be directly determined only at proportionally higher concentrations.

  2. Simultaneous detection of perchlorate and bromate using rapid high-performance ion exchange chromatography-tandem mass spectrometry and perchlorate removal in drinking water.

    Science.gov (United States)

    West, Danielle M; Mu, Ruipu; Gamagedara, Sanjeewa; Ma, Yinfa; Adams, Craig; Eichholz, Todd; Burken, Joel G; Shi, Honglan

    2015-06-01

    Perchlorate and bromate occurrence in drinking water causes health concerns due to their effects on thyroid function and carcinogenicity, respectively. The purpose of this study was threefold: (1) to advance a sensitive method for simultaneous rapid detection of perchlorate and bromate in drinking water system, (2) to systematically study the occurrence of these two contaminants in Missouri drinking water treatment systems, and (3) to examine effective sorbents for minimizing perchlorate in drinking water. A rapid high-performance ion exchange chromatography-tandem mass spectrometry (HPIC-MS/MS) method was advanced for simultaneous detection of perchlorate and bromate in drinking water. The HPIC-MS/MS method was rapid, required no preconcentration of the water samples, and had detection limits for perchlorate and bromate of 0.04 and 0.01 μg/L, respectively. The method was applied to determine perchlorate and bromate concentrations in total of 23 selected Missouri drinking water treatment systems during differing seasons. The water systems selected include different source waters: groundwater, lake water, river water, and groundwater influenced by surface water. The concentrations of perchlorate and bromate were lower than or near to method detection limits in most of the drinking water samples monitored. The removal of perchlorate by various adsorbents was studied. A cationic organoclay (TC-99) exhibited effective removal of perchlorate from drinking water matrices.

  3. Effect of temperature in cerium-ion-catalyzed bromate-driven oscillators

    Science.gov (United States)

    Nagy, Gabriella; Körös, Endre; Oftedal, Norunn; Tjelflaat, Kjetil; Ruoff, Peter

    1996-03-01

    The influence of substrate composition and initial reagent concentrations on activation energies in closed Ce-ion catalyzed Belousov-Zhabotinsky (BZ) reactions is reported. While changes in the initial concentration of organic substrate, bromate ion or sulfuric acid showed different changes in activation energies for the various organic substrate BZ systems, for all systems it was found that lowering the Ce-ion concentration leads to a significant decrease in the overall activation energy of the oscillator. When comparing the performance of a malonic acid oscillator run in a batch or in a continuous stirred flow reactor (CSTR), it was found that under CSTR conditions Q10 values may become as low as 1.3, while for the batch system the corresponding Q10 values are about 2.3.

  4. EFFECTS OF POTASSIUM BROMATE ON THE KIDNEY AND HAEMATOLOGICAL PARAMETERS OF SWISS ALBINO MICE

    Directory of Open Access Journals (Sweden)

    MARIA STUTI

    2013-01-01

    Full Text Available The present study aimed to investigate the possible effects of potassium bromate toxicity on histological,haematological and biochemical parameters in Swiss albino mice. Mice were orally administered with potassiumbromate at the rate of 150 mg/kg body weight daily in a single dose for 30, 60 and 120 days. The chemicalsignificantly reduced the RBC count (p<0.01 Hb% (p<0.01 and platelet count (p<0.01, while it increasedsignificantly the urea (p<0.01 and creatinine level (p<0.01 and decreased total protein and Albumin (p<0.01Histopathological examination showed degenerative changes of tubular cells, cytoplasma vacuolation, cellularinfiltration, tubular dilation with eosinophilic debris and clear cell cytoplasm were observed. These findingssuggest that KBrO3 affects the physiological and biochemical activities of Swiss albino mice

  5. Catalytic effects of trace ruthenium on oxidation of dimethyl yellow with bromate and its application

    Institute of Scientific and Technical Information of China (English)

    ZHOU Zhi-rong; WANG Qun; ZHANG Shu-yuan

    2008-01-01

    A spectrophotometric method for the determination of ruthenium(Ⅲ) is described, based on its catalytic effect on the oxidation reaction of dimethyl yellow (DMY) with potassium bromate in an acid solution medium and in the presence of an OP emulsifier (p-iso-octyl phenoxy polyethoxy ethanol) at 100 ℃. This reaction was followed spectrophotometrically by measuring the decrease in the absorbance at 530 nm of the catalytic reaction of DMY. The calibration curve for the recommended method was linear in the concentration range over 0.0-1.0 μg/Land the detection limit of the method for Ru(Ⅲ) was 0.01 μg/L. The method is highly sensitive, selective and very stable and has been successfully applied for the determination of trace amounts of ruthenium in some ores and metallurgy products with the relative standard deviations (RSD) over 1.6%-2.8% and a recovery over 98.7%-104.0%.

  6. A sensitive amperometric bromate sensor based on multi-walled carbon nanotubes/phosphomolybdic acid composite film

    International Nuclear Information System (INIS)

    An amperometric sensor for bromate was developed based on multi-walled carbon nanotubes (MWNTs)/phosphomolybdic acid (PMo12) composite film coated on a pyrolytic graphite (PG) electrode. MWNTs are dispersed in PMo12 aqueous solution through spontaneous and strong chemisorption between carbon and polyoxometalate, which results in a homogeneous MWNTs/PMo12 composite. Due to the unique electronic and electrocatalytic properties of MWNTs and PMo12, the combination of MWNTs and PMo12 results in a remarkable synergistic augmentation on the response current. The bromate sensor based on the PG/MWNTs/PMo12 electrode has excellent characteristics, such as a detection limit of 0.5 μM, a sensitivity of 760.9 μA mM-1 cm-2, a response time less than 2 s and a linear range from 5 μM to 15 mM

  7. Direct injection, simple and robust analysis of trace-level bromate and bromide in drinking water by IC with suppressed conductivity detection.

    Science.gov (United States)

    Lawal, Wasiu; Gandhi, Jay; Zhang, Chunlong Carl

    2010-08-01

    Bromide is ubiquitously found in drinking water. It is introduced into source water primarily by contact with bromide-containing soils or seawater having high bromide content. Bromide is converted into carcinogenic bromate during ozonation processes employed in some drinking water and wastewater treatment plants. Therefore, monitoring of bromate in drinking water and its precursor bromide in source water is required. The purpose of this study was to survey bromide and bromate concentrations in randomly selected bottle waters of various brands and several tap water samples in the coastal Houston area using a direct-injection ion chromatography (IC) and a suppressed conductivity system. The method employs a simple isocratic IC with loop injection with calculated detection limit of 0.009 microg/L for bromate and 0.028 microg/L for bromide (250-microL sample volume). Allowing the detection of both species at the microg/L level in drinking water, this method does not require specialized instrumentation such as two-dimensional IC, expensive sample preparation, or post-column reactions. The results show that, whereas bromate remains undetected in all five tap water samples, there are significant high concentrations of bromide in the coastal Houston area (294.79 +/- 56.97 microg/L). Its link to potential seawater intrusion need to be further investigated. For bottle water samples randomly collected, 18.2% (2 out of 11) showed detectable amount of both bromide and bromate. The detection of bromate coincides with those bottle water samples that underwent ozonation treatment. Further sample campaign with exclusively ozonated bottle water samples (n = 19) showed 100% detection rate for both bromide and bromate. The 99% confidence intervals were 14.45-37.97 microg/L and 0.32-2.58 microg/L for bromide and bromate, respectively. The highest level of bromate among all ozonated bottle water samples was 7.57 microg/L, a concentration close to the U.S. EPA prescribed limit for

  8. Association of brominated proteins and changes in protein expression in the rat kidney with subcarcinogenic to carcinogenic doses of bromate

    Energy Technology Data Exchange (ETDEWEB)

    Kolisetty, Narendrababu [Department of Pharmaceutical and Biomedical Sciences, College of Pharmacy, University of Georgia, Athens, GA 30602 (United States); Bull, Richard J. [MoBull Consulting, Richland, WA 99352 (United States); Muralidhara, Srinivasa; Costyn, Leah J. [Department of Pharmaceutical and Biomedical Sciences, College of Pharmacy, University of Georgia, Athens, GA 30602 (United States); Delker, Don A. [School of Medicine, University of Utah, Salt Lake City, UT 84132 (United States); Guo, Zhongxian [Water Quality Office, Public Utilities Board, 608576 (Singapore); Cotruvo, Joseph A. [Joseph Cotruvo and Associates, LLC, Washington, DC 20016 (United States); Fisher, Jeffrey W. [National Center for Toxicological Research, FDA, Jefferson, AR 72079 (United States); Cummings, Brian S., E-mail: bsc@rx.uga.edu [Department of Pharmaceutical and Biomedical Sciences, College of Pharmacy, University of Georgia, Athens, GA 30602 (United States)

    2013-10-15

    The water disinfection byproduct bromate (BrO{sub 3}{sup −}) produces cytotoxic and carcinogenic effects in rat kidneys. Our previous studies demonstrated that BrO{sub 3}{sup −} caused sex-dependent differences in renal gene and protein expression in rats and the elimination of brominated organic carbon in their urine. The present study examined changes in renal cell apoptosis and protein expression in male and female F344 rats treated with BrO{sub 3}{sup −} and associated these changes with accumulation of 3-bromotyrosine (3-BT)-modified proteins. Rats were treated with 0, 11.5, 46 and 308 mg/L BrO{sub 3}{sup −} in drinking water for 28 days and renal sections were prepared and examined for apoptosis (TUNEL-staining), 8-oxo-deoxyguanosine (8-oxoG), 3-BT, osteopontin, Kim-1, clusterin, and p-21 expression. TUNEL-staining in renal proximal tubules increased in a dose-related manner beginning at 11.5 mg BrO{sub 3}{sup −}/L in female rats and 46 mg/L in males. Increased 8-oxoG staining was observed at doses as low as 46 mg/L. Osteopontin expression also increased in a dose-related manner after treatment with 46 mg/L, in males only. In contrast, Kim-1 expression increased in a dose-related manner in both sexes, although to a greater extent in females at the highest dose. Clusterin and p21 expression also increased in a dose-related manner in both sexes. The expression of 3-BT-modified proteins only increased in male rats, following a pattern previously reported for accumulation of α-2{sub u}-globulin. Increases in apoptosis in renal proximal tubules of male and female rats at the lowest doses suggest a common mode of action for renal carcinogenesis for the two sexes that is independent of α-2{sub u}-globulin nephropathy. - Highlights: • Bromate induced nephrotoxicity in both male and female rats by similar mechanisms. • Apoptosis was seen in both male and female rats at the lowest doses tested. • Bromate-induced apoptosis correlated to 8-oxo

  9. [Determination of trace and ultra-trace level bromate in water by large volume sample injection with enrichment column for on-line preconcentration coupled with ion chromatography].

    Science.gov (United States)

    Liu, Jing; He, Qingqing; Yang, Lili; Hu, Enyu; Wang, Meifei

    2015-10-01

    A method for the determination of trace and ultra-trace level bromate in water by ion chromatography with large volume sample injection for on-line preconcentration was established. A high capacity Dionex IonPac AG23 guard column was simply used as the enrichment column instead of the loop for the preconcentration of bromate. High purity KOH solution used as eluent for gradient elution was on-line produced by an eluent generator automatically. The results showed that a good linear relationship of bromate was exhibited in the range of 0.05-51.2 μg/L (r ≥ 0.999 5), and the method detection limit was 0.01 μg/L. Compared with conventional sample injection, the injection volume was up to 5 mL, and the enrichment factor of this method was about 240 times. This method was successfully applied for several real samples of pure water which were purchased in the supermarket, and the recoveries of bromate were between 90%-100% with the RSDs (n = 6) of 2.1%-6.4% at two spiked levels. This method without pretreatment is simple, and of high accuracy and precision. The preconcentration can be achieved by large volume sample injection. It is suitable for the analysis of trace and ultra-trace level bromate.

  10. Stability of penta- and hexavalent americium in the solutions of sodium peroxydisulfate and sodium bromate at intensive internal α-irradiation

    International Nuclear Information System (INIS)

    The spectrometric method has been used for studying the dependence of the rates of radiolytic reduction of Am(5) and (6) on the initial concentration of sodium persulfate and bromate, Am(5) and (6), acidity, and the dose rate of inner alpha-irradiation of the solutions. The high dose rates of inner alpha-irradiation of solutions (up to 3.25x1021 eV/lxmin-250Ci/l) have been attained with the aid of curium isotopes. The stability of americium (6) ions towards the action of ionizing radiation in solutions of sodium persulfate and bromate has been shown to be considerable lower than that of americium (5). The chemical difference has been shown in radiolytic behaviour between Am(5) and Am(6) ions in solutions of sodium persulfate and bromate. The equations have been derived showing the dependence of the rates of Am(6) and Am(5) reduction of different variables

  11. Impact of potassium bromate and potassium iodate in a pound cake system.

    Science.gov (United States)

    Wilderjans, Edith; Lagrain, Bert; Brijs, Kristof; Delcour, Jan A

    2010-05-26

    This study investigates the impact of the oxidants potassium bromate and potassium iodate (8, 16, 32, 64, and 128 micromol/g dry matter of egg white protein) on pound cake making. The impact of the oxidants on egg white characteristics was studied in a model system. Differential scanning calorimetry showed that the oxidants caused egg white to denature later. During heating in a rapid visco analyzer, the oxidants caused the free sulfhydryl (SH) group levels to decrease more intensively and over a smaller temperature range. The oxidants made the proteins more resistant to decreases in protein extractability in sodium dodecyl sulfate containing buffer during cake recipe mixing and less resistant to such decreases during cake baking. We assume that, during baking, the degree to which SH/disulfide exchange and SH oxidation can occur depends on the properties of the protein at the onset of the process. In our view, the prevention of extractability loss during mixing increased the availability of SH groups and caused more such loss during baking. During cooling, all cakes baked with added oxidants showed less collapse. On the basis of the presented data, we put forward that only those protein reactions that occur during baking contribute to the formation of a network that supports final cake structure and prevents collapse. PMID:20423045

  12. Ameliorative effects of vanillin on potassium bromate induces bone and blood disorders in vivo.

    Science.gov (United States)

    Ben Saad, H; Ben Amara, I; Krayem, N; Boudawara, T; Kallel, C; Zeghal, K M; Hakim, A

    2015-11-08

    The objective of this study was to investigate the propensity of potassium bromate (KBrO3) to induce oxidative stress in blood and bone of adult mice and its possible attenuation by vanillin. Our results demonstrated, after KBrO3 treatment, a decrease of red blood cells and hemoglobin and a significant increase of white blood cell. A decrease in plasma levels of folic acid, vitamin B12 and iron was also noted. Interestingly, an increase of lipid peroxidation, hydroperoxides, hydrogen peroxide, advanced oxidation protein products and protein carbonyl levels in erythrocytes and bone was observed, while superoxide dismutase, catalase and glutathione peroxidase activities and glutathione, non-protein thiol and vitamin C levels were decreased. KBrO3 treatment resulted in blood and bone DNA fragmentation, a hallmark of genotoxicity-KBrO3-induced, with reduction of DNA levels. Calcium and phosphorus levels showed a decrease in the bone and an increase in the plasma after KBrO3 treatment. These biochemical alterations were accompanied by histological changes in the blood smear and bone tissue. Treatment with vanillin improved the histopathological, hematotoxic and genotoxic effects induced by KBrO3. The results showed, for the first time, that the vanillin possesses a potent protective effect against the oxidative stress and genotoxicity in bone and blood of KBrO3-treated mice.

  13. Phosphomolybdate-doped-poly(3,4-ethylenedioxythiophene) coated gold nanoparticles: Synthesis, characterization and electrocatalytic reduction of bromate

    Energy Technology Data Exchange (ETDEWEB)

    Hassan, Syeda Sara [School of Chemistry, Monash University, VIC 3800 (Australia); National Center of Excellence in Analytical Chemistry, University of Sindh, Jamshoro 76080 (Pakistan); Liu, Yuping [School of Chemistry, Monash University, VIC 3800 (Australia); Sirajuddin,; Solangi, Amber Rehana [National Center of Excellence in Analytical Chemistry, University of Sindh, Jamshoro 76080 (Pakistan); Bond, Alan M., E-mail: alan.bond@monash.edu [School of Chemistry, Monash University, VIC 3800 (Australia); Zhang, Jie, E-mail: jie.zhang@monash.edu [School of Chemistry, Monash University, VIC 3800 (Australia)

    2013-11-25

    Graphical abstract: -- Highlights: •Stable and water soluble phosphomolybdate-doped-PEDOT coated gold nanoparticles were synthesized. •Electrodes modified with these nanoparticles show well defined voltammetric response and excellent stability in acidic media. •These nanocomposite catalysts exhibit an excellent catalytic activity towards electroreduction of bromate. -- Abstract: Phosphomolybdate, H{sub 3}PMo{sub 12}O{sub 40}, (PMo{sub 12})-doped-poly(3,4-ethylenedioxythiophene) (PEDOT) coated gold nanoparticles have been synthesized in aqueous solution by reduction of AuCl{sub 4}{sup −} using hydroxymethyl EDOT as a reducing agent in the presence of polystyrene sulfonate and PMo{sub 12}. The resulting PMo{sub 12}-doped-PEDOT stabilized Au nanoparticles are water soluble and have been characterized by UV–visible spectroscopy, scanning electron microscopy and electrochemistry. Glassy carbon electrodes modified with these Au nanoparticles show excellent stability and catalytic activity towards the reduction of bromate in an aqueous electrolyte solution containing 10 mM H{sub 2}SO{sub 4} and 0.1 M Na{sub 2}SO{sub 4}.

  14. Phosphomolybdate-doped-poly(3,4-ethylenedioxythiophene) coated gold nanoparticles: Synthesis, characterization and electrocatalytic reduction of bromate

    International Nuclear Information System (INIS)

    Graphical abstract: -- Highlights: •Stable and water soluble phosphomolybdate-doped-PEDOT coated gold nanoparticles were synthesized. •Electrodes modified with these nanoparticles show well defined voltammetric response and excellent stability in acidic media. •These nanocomposite catalysts exhibit an excellent catalytic activity towards electroreduction of bromate. -- Abstract: Phosphomolybdate, H3PMo12O40, (PMo12)-doped-poly(3,4-ethylenedioxythiophene) (PEDOT) coated gold nanoparticles have been synthesized in aqueous solution by reduction of AuCl4− using hydroxymethyl EDOT as a reducing agent in the presence of polystyrene sulfonate and PMo12. The resulting PMo12-doped-PEDOT stabilized Au nanoparticles are water soluble and have been characterized by UV–visible spectroscopy, scanning electron microscopy and electrochemistry. Glassy carbon electrodes modified with these Au nanoparticles show excellent stability and catalytic activity towards the reduction of bromate in an aqueous electrolyte solution containing 10 mM H2SO4 and 0.1 M Na2SO4

  15. Oscillatory dynamics in systems containing bromate and 1,4-cyclohexanedione in acidic media. I. The effect of temperature; Dinamica oscilatoria em sistemas contendo bromato e 1,4-ciclo-hexanodiona em meio acido. I. Efeito da temperatura

    Energy Technology Data Exchange (ETDEWEB)

    Oliveira, Hyrla C.L.; Oliveira, Tatiane B.; Varela, Hamilton, E-mail: varela@iqsc.usp.br [Instituto de Quimica de Sao Carlos, Universidade de Sao Paulo (IQSC/USP), Sao Carlos, SP (Brazil)

    2012-07-01

    We present in this work the influence of temperature on the dynamics of homogeneous chemical systems containing bromate and 1,4-cyclohexanedione (1,4-CHD) in acidic media. In particular, the following systems were studied: bromate/1,4-CHD/acid, bromate/1,4-CHD/ferroin/acid and bromate/1,4-CHD/trisbipyridine ruthenium/acid. Investigations were carried out by means of an electrochemical probe, at five temperatures between 5 and 45 degree C. Activation energies (Ea) were estimated in different ways for the pre-oscillatory and oscillatory regimes. In any case, the Ea was found to depend on the catalyst, composition and initial concentrations. In addition, it was observed that ferroin and trisbipyridine ruthenium act as catalysts only during the transition between the induction period and oscillatory regime. (author)

  16. Development of a miniature dielectric barrier discharge–optical emission spectrometric system for bromide and bromate screening in environmental water samples

    International Nuclear Information System (INIS)

    Graphical abstract: -- Highlights: •Dielectric barrier discharge (DBD) is for the first time used as a radiation source for the excitation of bromine and its emission. •A DBD–optical emission spectrometric (OES) system was developed for the detection of bromide and bromate. •The DBD–OES system has been demonstrated by screening trace bromide and bromate in a series of environmental water samples. -- Abstract: Dielectric barrier discharge (DBD) at atmospheric pressure provides an efficient radiation source for the excitation of bromine and it is used for the first time for optical emission spectrometric (OES) detection of bromide and bromate. A portable DBD–OES system is developed for screening potential pollution from bromide and bromate in environmental waters. Bromide is on-line oxidized to bromine for in-situ generation of volatile bromine. Meanwhile, a helium stream carries bromine into the DBD micro-plasma for its excitation at a discharging voltage of 3.7 kV and optical emission spectrometric detection with a QE65000 charge-coupled device (CCD) spectrometer in the near-infrared spectral region. Similarly, the quantification of bromate is performed by its pre-reduction into bromide and then oxidized to bromine. The spectral characteristics and configuration of the DBD micro-plasma excitation source in addition to the oxidation vapor generation of bromine have been thoroughly investigated. With a sampling volume of 1 mL, a linear range of 0.05–10.0 mg L−1 is obtained with a detection limit of 0.014 mg L−1 by measuring the emission at 827 nm. A precision of 2.3% is achieved at 3 mg L−1 bromide. The system is validated by bromine detection in certified reference material of laver (GBW10023) at mg L−1 level, giving rise to satisfactory agreement. In addition, it is further demonstrated by screening trace bromide and bromate as well as spiking recoveries in a series of environmental water samples

  17. A New Reaction for Kinetic Spetrophotometric Determination of Trace Ruthenium--Catalytic Oxidation of Methyl Green by Bromate

    Institute of Scientific and Technical Information of China (English)

    ZHOU Zhi-rong; XU Qiong; XIONG Yan; WEI Jia-wen

    2006-01-01

    A sensitive catalytic spectrophotometric method for the determination of ruthenium (Ⅲ) has been developed, based on its catalytic effect on the oxidation reaction of methyl green with potassium bromate in acid solution medium at 100 ℃. The above reaction is followed spectrophotometrically by measuring the decrease in the absorbance at 625 nm for the catalytic reaction of methyl green. The calibration curve for the recommended reaction-rate method was linear in the concentration range over 0.00-0.80 μg/L and the detection limit of the method for Ru (Ⅲ) is 0.006μg/L. Almost no foreign ions interfered in the determination at less than 25-fold concentration of Ru (Ⅲ). The method is highly sensitive, more selective and very stable, and has been successfully applied for the determination of trace ruthenium in some ores and metallurgy products.

  18. Spectrophotometric Method for Estimation of Tamsulosin Hydrochloride in Pharmaceutical Dosage Form Using Bromate-Bromide and Methyl Orange Reagent

    Directory of Open Access Journals (Sweden)

    Bharatkumar Ganeshbhai Chaudhari

    2012-09-01

    Full Text Available A simple, rapid, accurate and precise assay procedure based on Spectrophotometric method has been developed for the estimation of Tamsulosin hydrochloride in Pharmaceutical formulation. The method was based on the bromination of Tamsulosin hydrochloride with a known excess amount of Bromate-bromide mixture in acidic medium followed by the determination of surplus bromine by reacting with dye methyl orange and measuring the absorbance at 513 nm. Validation was carried out in compliance with International Conference on Harmonization guidelines. Linear regression analysis of method showed good linearity with the correlation co-efficient (r of 0.9978 with respect to absorbance in the concentration range of 2-12 μg/mL and the mean recovery for Tamsulosin hydrochloride was 99.65% ± 0.47 . The proposed method can be successfully applied for the analysis of tablet formulations.

  19. Spectrophotometric reaction rate method for the determination of osmium by its catalytic effect on the oxidation of gallocyanine by bromate.

    Science.gov (United States)

    Ensafi, A A; Shamss-E-Sollari, E

    1994-10-01

    A simple kinetic spectrophotometric method was developed for the determination of osmium. The method is based on the catalytic effect of osmium as osmium tetroxide on the oxidation of gallocyanine by bromate at pH 7. The reaction is monitored spectrophotometrically by measuring the decreasing absorbance of gallocyanine at 620 nm by the fixed-time method. A detection limit of 0.01 ng/ml and linear calibration curve from 0.1 to 100 and from 100 to 1200 ng/ml Os(VIII) is reported. The relative standard deviation for 0.0100 microg/ml Os(VIII) is 0.8% (N = 10). The method is free from most interferences. Osmium in synthetic samples is determined by this method, with satisfactory results. PMID:18966116

  20. The indirect effect of radiation reduces the repair fidelity of NHEJ as verified in repair deficient CHO cell lines exposed to different radiation qualities and potassium bromate

    Energy Technology Data Exchange (ETDEWEB)

    Bajinskis, Ainars, E-mail: ainars.bajinskis@gmt.su.se [Centre for Radiation Protection Research, Department of Genetics, Microbiology and Toxicology, Stockholm University, S-10691 Stockholm (Sweden); Olsson, Gunilla; Harms-Ringdahl, Mats [Centre for Radiation Protection Research, Department of Genetics, Microbiology and Toxicology, Stockholm University, S-10691 Stockholm (Sweden)

    2012-03-01

    The complexity of DNA lesions induced by ionizing radiation is mainly dependent on radiation quality, where the indirect action of radiation may contribute to different extent depending on the type of radiation under study. The effect of indirect action of radiation can be investigated by using agents that induce oxidative DNA damage or by applying free radical scavengers. The aim of this study was to investigate the role of the indirect effect of radiation for the repair fidelity of non-homologous end-joining (NHEJ), homologous recombination repair (HRR) and base excision repair (BER) when DNA damage of different complexity was induced by gamma radiation, alpha particles or from base damages (8-oxo-dG) induced by potassium bromate (KBrO{sub 3}). CHO cells lines deficient in XRCC3 (HRR) irs1SF, XRCC7 (NHEJ) V3-3 and XRCC1 (BER) EM9 were irradiated in the absence or presence of the free radical scavenger dimethyl sulfoxide (DMSO). The endpoints investigated included rate of cell proliferation by the DRAG assay, clonogenic cell survival and the level of primary DNA damage by the comet assay. The results revealed that the indirect effect of low-LET radiation significantly reduced the repair fidelity of both NHEJ and HRR pathways. For high-LET radiation the indirect effect of radiation also significantly reduced the repair fidelity for the repair deficient cell lines. The results suggest further that the repair fidelity of the error prone NHEJ repair pathway is more impaired by the indirect effect of high-LET radiation relative to the other repair pathways studied. The response to bromate observed for the two DSB repair deficient cell lines strongly support earlier studies that bromate induces complex DNA damages. The significantly reduced repair fidelity of irs1SF and V3-3 suggests that NHEJ as well as HRR are needed for the repair, and that complex DSBs are formed after bromate exposure.

  1. Enhanced bromate formation during chlorination of bromide-containing waters in the presence of CuO: Catalytic disproportionation of hypobromous acid

    KAUST Repository

    Liu, Chao

    2012-10-16

    Bromate (BrO3 -) in drinking water is traditionally seen as an ozonation byproduct from the oxidation of bromide (Br-), and its formation during chlorination is usually not significant. This study shows enhanced bromate formation during chlorination of bromide-containing waters in the presence of cupric oxide (CuO). CuO was effective to catalyze hypochlorous acid (HOCl) or hypobromous acid (HOBr) decay (e.g., at least 104 times enhancement for HOBr at pH 8.6 by 0.2 g L-1 CuO). Significant halate concentrations were formed from a CuO-catalyzed hypohalite disproportionation pathway. For example, the chlorate concentration was 2.7 ± 0.2 μM (225.5 ± 16.7 μg L-1) after 90 min for HOCl (Co = 37 μM, 2.6 mg L-1 Cl2) in the presence of 0.2 g L-1 CuO at pH 7.6, and the bromate concentration was 6.6 ± 0.5 μM (844.8 ± 64 μg L -1) after 180 min for HOBr (Co = 35 μM) in the presence of 0.2 g L-1 CuO at pH 8.6. The maximum halate formation was at pHs 7.6 and 8.6 for HOCl or HOBr, respectively, which are close to their corresponding pKa values. In a HOCl-Br--CuO system, BrO3 - formation increases with increasing CuO doses and initial HOCl and Br- concentrations. A molar conversion (Br - to BrO3 -) of up to (90 ± 1)% could be achieved in the HOCl-Br--CuO system because of recycling of Br - to HOBr by HOCl, whereas the maximum BrO3 - yield in HOBr-CuO is only 26%. Bromate formation is initiated by the formation of a complex between CuO and HOBr/OBr-, which then reacts with HOBr to generate bromite. Bromite is further oxidized to BrO3 - by a second CuO-catalyzed process. These novel findings may have implications for bromate formation during chlorination of bromide-containing drinking waters in copper pipes. © 2012 American Chemical Society.

  2. Vanillin mitigates potassium bromate-induced molecular, biochemical and histopathological changes in the kidney of adult mice.

    Science.gov (United States)

    Ben Saad, Hajer; Driss, Dorra; Ellouz Chaabouni, Samia; Boudawara, Tahia; Zeghal, Khaled Mounir; Hakim, Ahmed; Ben Amara, Ibtissem

    2016-05-25

    The present study aimed to explore the ability of vanillin to ameliorate the adverse effects induced by potassium bromate (KBrO3) in the renal tissue. Our results showed a significant increase in hydrogen peroxide, superoxide anion, malondialdehyde, advanced oxidation protein product and protein carbonyl levels in the kidney of KBrO3 treated mice, compared with the control group. Nephrotoxicity was evidenced by a decrease in plasma uric acid and kidney glutathione levels, Na(+)-K(+)-ATPase, lactate dehydrogenase and catalase activities. Additionally, creatinine and urea levels significantly increased in the plasma and declined in the urine. Also, Kidney glutathione peroxidase, superoxide dismutase, metallothionein (MT1 and MT2) mRNA expression remarkably increased. These modifications in biochemical and molecular values were substantiated by histopathological data. Co-treatment with vanillin restored these parameters to near control values. Interestingly, vanillin proved to possess, in vitro, a stronger scavenging radical activity than vitamin C and Trolox. Thus, vanillin inhibited KBrO3-induced damage via its antioxidant and antiradical activities as well as its capacity to protect genes expression and histopathological changes. PMID:27074584

  3. pH-oscillations in the bromate-sulfite reaction in semibatch and in gel-fed batch reactors

    Science.gov (United States)

    Poros, Eszter; Kurin-Csörgei, Krisztina; Szalai, István; Rábai, Gyula; Orbán, Miklós

    2015-06-01

    The simplest bromate oxidation based pH-oscillator, the two component BrO3--SO32- flow system was transformed to operate under semibatch and closed arrangements. The experimental preconditions of the pH-oscillations in semibatch configuration were predicted by model calculations. Using this information as guideline large amplitude (ΔpH˜3), long lasting (11-24 h) pH-oscillations accompanied with only a 20% increase of the volume in the reactor were measured when a mixture of Na2SO3 and H2SO4 was pumped into the solution of BrO3- with a very low rate. Batch-like pH-oscillations, similar in amplitude and period time appeared when the sulfite supply was substituted by its dissolution from a gel layer prepared previously in the reactor in presence of high concentration of Na2SO3. The dissolution vs time curve and the pH-oscillations in the semibatch and closed systems were successfully simulated. Due to the simplicity in composition and in experimental technique, the semibatch and batch-like BrO3--SO32- pH-oscillators may become superior to their CSTR (continuous flow stirred tank reactor) version in some present and future applications.

  4. Vanillin mitigates potassium bromate-induced molecular, biochemical and histopathological changes in the kidney of adult mice.

    Science.gov (United States)

    Ben Saad, Hajer; Driss, Dorra; Ellouz Chaabouni, Samia; Boudawara, Tahia; Zeghal, Khaled Mounir; Hakim, Ahmed; Ben Amara, Ibtissem

    2016-05-25

    The present study aimed to explore the ability of vanillin to ameliorate the adverse effects induced by potassium bromate (KBrO3) in the renal tissue. Our results showed a significant increase in hydrogen peroxide, superoxide anion, malondialdehyde, advanced oxidation protein product and protein carbonyl levels in the kidney of KBrO3 treated mice, compared with the control group. Nephrotoxicity was evidenced by a decrease in plasma uric acid and kidney glutathione levels, Na(+)-K(+)-ATPase, lactate dehydrogenase and catalase activities. Additionally, creatinine and urea levels significantly increased in the plasma and declined in the urine. Also, Kidney glutathione peroxidase, superoxide dismutase, metallothionein (MT1 and MT2) mRNA expression remarkably increased. These modifications in biochemical and molecular values were substantiated by histopathological data. Co-treatment with vanillin restored these parameters to near control values. Interestingly, vanillin proved to possess, in vitro, a stronger scavenging radical activity than vitamin C and Trolox. Thus, vanillin inhibited KBrO3-induced damage via its antioxidant and antiradical activities as well as its capacity to protect genes expression and histopathological changes.

  5. Kinetics and mechanism of oxidation of dimethyl sulphoxide by sodium bromate-sodium bisulphite reagent in aqueous medium

    Indian Academy of Sciences (India)

    J Viroopakshappa; V Jagannadham

    2002-04-01

    Rates of oxidation of dimethyl sulphoxide (DMSO) by HOBr produced in situ from sodium bromate-sodium bisulphite reagent have been studied iodometrically in aqueous medium. The order in [DMSO] is one when [DMSO] < 0.01 mol dm-3, fractional when [DMSO] is between 0.01 and 0.5 mol dm-3 and zero when (DMSO) < 0.5 mol dm-3. Different rate laws are operative under these three conditions though HOBr is the effective oxidizing species in all the cases. A mechanism involving an intermediate four-membered cyclic transition state between DMSO and HOBr (formation constant ), which decomposes in a slow step with a rate constant () has been proposed. Thermodynamic parameters for the adduct formation step and activation parameters for the first-order decomposition of the adduct step have been evaluated in the temperature range 308-323 K. Activation parameters have also been determined while the orders in [DMSO] are unity and zero. The reaction product has been identified as dimethyl sulphone (DMSO2).

  6. Formation potentials of bromate and brominated disinfection by-products in bromide-containing water by ozonation.

    Science.gov (United States)

    Lin, Tao; Wu, Shouke; Chen, Wei

    2014-12-01

    The ozonation involved in drinking water treatment raises issues of water quality security when the raw water contains bromide (Br(-)). Br(-) ions may be converted to bromate (BrO3 (-)) during ozonation and some brominated disinfection by-products (Br-DBPs) in the following chlorination. In this study, the effects of ozone (O3) dosage, contact time, pH, and Br(-) and ammonia (NH3-N) concentrations on the formation of BrO3 (-) and Br-DBPs have been investigated. The results show that decreasing the initial Br(-) concentration is an effective means of controlling the formation of BrO3 (-). When the concentration of Br(-) was lower than 100 μg/L, by keeping the ratio of O3 dosage to dissolved organic carbon (DOC) concentration at less than 1, BrO3 (-) production was effectively suppressed. The concentration of BrO3 (-) steadily increased with increasing O3 dosage at high Br(-) concentration (>900 μg/L). Additionally, a longer ozonation time increased the concentrations of BrO3 (-) and total organic bromine (TOBr), while it had less impact on the formation potentials of brominated trihalomethanes (Br-THMFP) and haloacetic acids (Br-HAAFP). Higher pH value and the presence of ammonia may lead to an increase in the formation potential of BrO3 (-) and Br-DBPs.

  7. The influence of the combined effects of acute gamma-radiation, sodium bromate and sodium nitrate on lettuce (Lactuca sativa) seedling root growth

    Energy Technology Data Exchange (ETDEWEB)

    Pryakhin, E.; Osipov, D. [Urals Research Center for Radiation Medicine - URCRM (Russian Federation)

    2014-07-01

    Among special industrial reservoirs used for the storage of liquid radioactive waste of Mayak PA, Russia, one of the most radioactively contaminated is the R-17 reservoir, so-called 'Staroye Boloto' (the total β-activity of water ranged in the observation period from 0.4 MBq/l to 4.5 MBq/l, the total a-activity ranged from 43 to 420 Bq/l). Also this reservoir is characterized by high level of chemical contamination, in particular, the concentration of nitrates in water is 2.5-4,4 g/l, sodium bromate - up to 35 mg/l. One of the interesting questions is interaction of radiation and chemical contamination in their effect on living organisms in this reservoir. In laboratory experiments seeds of Lactuca sativa were used; the effect of the studied factor on the length of the sprout's root was estimated. To assess the effect of chemical toxicants the solutions of each salt in 7 different concentrations were used, distilled water was used as a control. For evaluation of acute effects of external gamma irradiation the seeds after exposure for 24 hours in distilled water, were irradiated at 7 different doses using gamma-unit on the basis of Cs-137 with the dose rate of 0.62 Gy/min. To assess the combined effects of acute external gamma irradiation, of nitrates and bromates, seeds after 24 hour exposure at each test concentration of the salts solutions were irradiated using gamma-unit. To calculate the effective concentrations or doses was used drc package for R software. To calculate the dose rate to aquatic organisms in the R-17 was used ERICA Assessment Tool 2012. It was found out that the EC50 of sodium nitrate for lettuce was 2.69 g/l, which is comparable to the concentration of nitrates in the 'Staroye Boloto'. This indicates that nitrate can have significant toxic effect on aquatic higher plants of the reservoir. The EC50 of sodium bromate was 14.6 mg/l. This is less than the maximum concentration of the substance in the R-17, which suggests

  8. The influence of the combined effects of acute gamma-radiation, sodium bromate and sodium nitrate on lettuce (Lactuca sativa) seedling root growth

    International Nuclear Information System (INIS)

    Among special industrial reservoirs used for the storage of liquid radioactive waste of Mayak PA, Russia, one of the most radioactively contaminated is the R-17 reservoir, so-called 'Staroye Boloto' (the total β-activity of water ranged in the observation period from 0.4 MBq/l to 4.5 MBq/l, the total a-activity ranged from 43 to 420 Bq/l). Also this reservoir is characterized by high level of chemical contamination, in particular, the concentration of nitrates in water is 2.5-4,4 g/l, sodium bromate - up to 35 mg/l. One of the interesting questions is interaction of radiation and chemical contamination in their effect on living organisms in this reservoir. In laboratory experiments seeds of Lactuca sativa were used; the effect of the studied factor on the length of the sprout's root was estimated. To assess the effect of chemical toxicants the solutions of each salt in 7 different concentrations were used, distilled water was used as a control. For evaluation of acute effects of external gamma irradiation the seeds after exposure for 24 hours in distilled water, were irradiated at 7 different doses using gamma-unit on the basis of Cs-137 with the dose rate of 0.62 Gy/min. To assess the combined effects of acute external gamma irradiation, of nitrates and bromates, seeds after 24 hour exposure at each test concentration of the salts solutions were irradiated using gamma-unit. To calculate the effective concentrations or doses was used drc package for R software. To calculate the dose rate to aquatic organisms in the R-17 was used ERICA Assessment Tool 2012. It was found out that the EC50 of sodium nitrate for lettuce was 2.69 g/l, which is comparable to the concentration of nitrates in the 'Staroye Boloto'. This indicates that nitrate can have significant toxic effect on aquatic higher plants of the reservoir. The EC50 of sodium bromate was 14.6 mg/l. This is less than the maximum concentration of the substance in the R-17, which suggests that sodium bromate has a

  9. Reuse of sewage sludge as a catalyst in ozonation - Efficiency for the removal of oxalic acid and the control of bromate formation

    Energy Technology Data Exchange (ETDEWEB)

    Wen, Gang [State Key Laboratory of Urban Water Resource and Environment, Harbin Institute of Technology, Harbin 150090 (China); Pan, Zhi-Hui [School Of Civil Engineering, Guangzhou University, Guangzhou 510006 (China); Ma, Jun, E-mail: majun@hit.edu.cn [State Key Laboratory of Urban Water Resource and Environment, Harbin Institute of Technology, Harbin 150090 (China); Liu, Zheng-Qian, E-mail: liuzhengqian@gmail.com [School of Environmental Science and Engineering, Huazhong University of Science and Technology, Wuhan 430074 (China); Zhao, Lei [School of Civil Engineering, Harbin Institute of Technology, Harbin 150090 (China); Li, Jun-Jing [State Key Laboratory of Urban Water Resource and Environment, Harbin Institute of Technology, Harbin 150090 (China)

    2012-11-15

    Highlights: Black-Right-Pointing-Pointer Sewage sludge was converted into catalyst (SBC) and characterized. Black-Right-Pointing-Pointer SBC can enhance oxalic acid degradation in ozonation. Black-Right-Pointing-Pointer Surface reaction mechanism is responsible for enhancement of ozonation by SBC. Black-Right-Pointing-Pointer SBC can control the formation of bromate in ozonation. Black-Right-Pointing-Pointer Several combined reasons for the control of bromate formation are proposed. - Abstract: Sewage derived sludge is produced with an annual amount increase of 2% all over the world and it is an urgent issue to be addressed by human being. In the present study, sludge was converted into sludge-based catalyst (SBC) with ZnCl{sub 2} as activation agent and characterized by several methods (e.g., scanning electron microscope, X-ray photoelectron spectroscope and Fourier transform infrared spectroscope). Then it was used as a catalyst to enhance the removal of refractory organic matter, oxalic acid, and to control the formation of bromate (BrO{sub 3}{sup -}) in bench semi-continuous ozonation experiments. The effects of various operating parameters on the control of BrO{sub 3}{sup -} formation were investigated. Furthermore, the mechanism for the enhancement of organic matter removal and the control of BrO{sub 3}{sup -} formation was discussed as well. Results indicate that the combination of SBC with ozone shows a strong synergistic effect, resulting in a notable improvement on oxalic acid removal. A crucial surface reaction mechanism for the enhancement of organic matter removal is proposed on the basis of negative effect of higher pH and no inhibition effect of tert-butanol. The control for BrO{sub 3}{sup -} formation was demonstrated and the reason for its control in the process of O{sub 3}/SBC is the combined effect of SBC reductive properties, ozone exposure decrease and hydrogen peroxide concentration increase.

  10. Acute Toxic Effects of Bromate on Aquatic Organisms%溴酸盐对水生生物的急性毒性效应

    Institute of Scientific and Technical Information of China (English)

    王执伟; 刘冬梅; 张文娟; 崔福义

    2016-01-01

    Acute toxic effects of potassium bromate, sodium bromate and potassium bromide on luminescent bacteria, water flea, green alga and zebrafish were studied using standard toxic testing methods. The results showed that the pollutants had no effect on the luminous intensity of luminescent bacteria. The 96 h EC50 of potassium bromate on Scenedesmus obliquus was 738. 18 mg•L - 1 , 48 h EC50 on Daphnia magna and Moina was 154. 01 mg•L - 1 was 161. 80 mg•L - 1 , while 48 h LC50 was 198. 52 mg•L - 1 , 175. 68 mg•L - 1 , and 96 h LC50 on zebrafish was 931. 4 mg•L - 1 . The 96 h EC50 of sodium bromate on Scenedesmus obliquus was 540. 26 mg•L - 1 , 48 h EC50 on Daphnia magna and Moina was 127. 90 mg•L - 1 , 111. 07 mg•L - 1 , while 48 h LC50 was 161. 80 mg•L - 1 , 123. 47 mg•L - 1 , and 96 h LC50 on zebrafish was 1 065. 6 mg•L - 1 . But the effects of potassium bromide on the above several kinds of aquatic organisms were far smaller than those of potassium bromate and sodium bromate. The toxic effects on test organisms were due to the impacts of bromate after the comparison of different pollutants, and the effects were more obvious with the increase of exposure time. The order of sensitivity to the toxic effects of bromate was Daphnia magna, Moina > Scenedesmus obliquus > zebrafish > Chlorella vulgaris, luminescent bacteria.%采用标准毒性测试方法,分析了溴酸钾、溴酸钠、溴化钾对水生生态系统中不同营养级生物包括发光菌、绿藻、水蚤、斑马鱼的急性毒性效应.结果表明,3种污染物对发光菌发光强度几乎没有影响,溴酸钾对斜生栅藻的96 h EC50为738.18 mg•L -1;对大型蚤和裸腹蚤的48 h EC50分别为154.01 mg•L -1 和 161.80 mg•L -1 ,48 h LC50分别为198.52 mg•L -1 和 175.68 mg•L -1;对斑马鱼的96 h LC50为931.4 mg•L -1 . 溴酸钠对斜生栅藻的96 h EC50为540.26 mg•L -1;对大型蚤和裸腹蚤的48 h EC50分别为127.90 mg•L -1 和 111.07 mg•L -1

  11. Chemoprotective effect of taurine on potassium bromate-induced DNA damage, DNA-protein cross-linking and oxidative stress in rat intestine.

    Directory of Open Access Journals (Sweden)

    Mir Kaisar Ahmad

    Full Text Available Potassium bromate (KBrO3 is widely used as a food additive and is a major water disinfection by-product. It induces multiple organ toxicity in humans and experimental animals and is a probable human carcinogen. The present study reports the protective effect of dietary antioxidant taurine on KBrO3-induced damage to the rat intestine. Animals were randomly divided into four groups: control, KBrO3 alone, taurine alone and taurine+ KBrO3. Administration of KBrO3 alone led to decrease in the activities of intestinal brush border membrane enzymes while those of antioxidant defence and carbohydrate metabolism were also severely altered. There was increase in DNA damage and DNA-protein cross-linking. Treatment with taurine, prior to administration of KBrO3, resulted in significant attenuation in all these parameters but the administration of taurine alone had no effect. Histological studies supported these biochemical results showing extensive intestinal damage in KBrO3-treated animals and greatly reduced tissue injury in the taurine+ KBrO3 group. These results show that taurine ameliorates bromate induced tissue toxicity and oxidative damage by improving the antioxidant defence, tissue integrity and energy metabolism. Taurine can, therefore, be potentially used as a therapeutic/protective agent against toxicity of KBrO3 and related compounds.

  12. Combination of UV absorbance and electron donating capacity to assess degradation of micropollutants and formation of bromate during ozonation of wastewater effluents.

    Science.gov (United States)

    Chon, Kangmin; Salhi, Elisabeth; von Gunten, Urs

    2015-09-15

    In this study, the changes in UV absorbance at 254 nm (UVA254) and electron donating capacity (EDC) were investigated as surrogate indicators for assessing removal of micropollutants and bromate formation during ozonation of wastewater effluents. To measure the EDC, a novel method based on size exclusion chromatography followed by a post-column reaction was developed and calibrated against an existing electrochemical method. Low specific ozone doses led to a more efficient abatement of EDC than of UVA254. This was attributed to the abatement of phenolic moieties in the dissolved organic matter (DOM), which lose their EDC upon oxidation, but are partially transformed into quinones, which still absorb in the measured UV range. For higher specific ozone doses, the relative EDC abatement was lower than the relative UVA abatement, which can be explained by the oxidation of UV absorbing moieties (e.g. non-activated aromatic compounds), which contribute less to EDC. The abatement of the selected micropollutants (i.e., 17α-ethinylestradiol (EE2), carbamazepine (CBZ), atenolol (ATE), bezafibrate (BZF), ibuprofen (IBU), and p-chlorobenzoic acid (pCBA)) varied significantly depending on their reactivity with ozone in the examined specific ozone dose range of 0-1.45 mgO3/mgDOC. The decrease of EE2 and CBZ with high ozone reactivity was linearly proportional to the reduction of the relative residuals of UVA254 and EDC. The abatement of ATE, BZF, IBU, and pCBA with intermediate to low ozone reactivities was not significant in a first phase (UVA254/UVA254,0 = 1.00-0.70; EDC/EDC0 = 1.00-0.56) while their abatement was more efficient than the degradation of the relative residual UVA254 and much more noticeable than the degradation of the relative residual EDC in a second phase (UVA254/UVA254,0 = 0.70-0.25; EDC/EDC0 = 0.56-0.25) because the partially destroyed UV absorbing and electron donating DOM moieties become recalcitrant to ozone attack. Bromate formation was

  13. Oscillatory reactions in the acetone-glucose-sodium bromate-sulfuric acid system with a tetraazamacrocyclic copper (II complex as a catalyst

    Directory of Open Access Journals (Sweden)

    Hu Lin

    2016-01-01

    Full Text Available The behavior of glycolysis concerning the biochemical reaction was thought to be similar to the oscillatory reaction with glucose being the substrate. The objective of this research is to find a new oscillatory system and study its relevant properties, so new Cu (II-catalyzed oscillating reaction involved glucose and acetone as the double substrates was investigated systematically. As a function of reaction temperature and concentration of glucose, bromate, and acetone, the features in this novel oscillation system was studied. The results showed that the activation energy reached up to 90.839 KJ/mol and the oxidized product of the double substrates provided the impetus in the course of the new oscillating reaction. A tentative mechanism was considered on the basis of FNK.

  14. 村镇供水中臭氧消毒副产物溴酸盐生成规律研究%Study on formation law of byproduct——bromate during ozone disinfection for rural drinking water supply

    Institute of Scientific and Technical Information of China (English)

    贾燕南; 宋卫坤; 李晓琴; 胡孟; 刘文朝

    2013-01-01

    结合村镇供水特点,本文采取三种投加方式对9省63份作为饮用水水源的地下水水样进行臭氧投加试验,考察了不同地区的水样消毒后生成溴酸盐浓度水平的差异,研究了臭氧投加量、投加方式对溴酸盐生成浓度的影响.结果表明:原水溴离子浓度越低,pH值越低,投加臭氧后生成的溴酸盐量也较小;溴酸盐生成量与臭氧投加量在一定范围内呈线性正相关关系.同一投加量下,三种臭氧投加方式对应的溴酸盐生成量由小到大依次为:投加高浓度臭氧水、水射器投加、直接通入臭氧气体.%In accordance with the characteristics of rural drinking water supply, the ozone adding experiment on the groundwater samples from 63 water sources for the rural drinking water in 9 provinces is made with three ozone dosing methods, and then the difference among the levels of bromate concentrations formed after the disinfections of the water samples from various areas is investigated and the impacts from both the ozone dosing and the dosing method on the bromate forming concentration are studied.The result shows that the less the bromonium ion concentration of the raw water is, the lower the pH value is to be, and then the less content of the bromate formed after ozone adding is to be as well, while the bromate formation shows linear positive correlation with the ozone dosage with a certain range.Under an identical dosing, the bromate formations corresponded to the three o-zone dosing methods, i.e.adding high concentration ozone water, adding by water-jet, direct adding of ozone gas, vary in an order from less to large.

  15. Determination of Bromate in Wheat Flour and Wheat Flour Products%小麦粉及小麦粉制品中溴酸盐的测定

    Institute of Scientific and Technical Information of China (English)

    陶大利; 苑向杰

    2012-01-01

    A method for determination of bromate in wheat flour and wheat flour products by Ion chromatography method is reported.The chromatographic column for DIONEX AS19(250mm×4.0mm),eluent(mobile phase) for KOH solution,Conductivity detector,extraced by pure water samples of bromate ion(BrO-3),RP(C18) column was used to remove the organic matter,the Ag/H column to remove sample extraction liquid disturbance in the chloride ion(Cl-),using ion chromatography conductivity detector for the determination,quantified by external standard method.Linear ranges of lutein was 0.05~2.0μg/mL,the linear equation was y=1.435x-0.031,relevant index R2=0.9998;Concentration in the 1.60mg/kg~4.80mg/kg range,the average recovery rate were 92.8~103.5%.%建立离子色谱法测定小麦粉及其小麦粉制品中溴酸盐的测定方法。采用的色谱柱为戴安的AS19(250×4.6mm),淋洗液(流动相)为KOH溶液。用纯水提取样品中溴酸根离子(BrO3-),经RP(C18)柱除去样品中得有机物,经Ag/H柱除去样品提取液中干扰氯离子(Cl-),采用离子交换色谱-电导检测器测定,外标法定量,经测试溴酸盐在0.05~2.0μg/mL范围内,线性良好,线性方程为y=1.435x-0.031,相关系数R=0.9998,添加浓度在1.60mg/kg~4.80mg/kg范围内,平均回收率在97.5%~98.4%之间。

  16. The Protective Effect of Ethanolic Extract of Unripe Pulp of Carica papaya (Pawpaw Against Potassium Bromate Induced Tissue Damage in Wistar Rats

    Directory of Open Access Journals (Sweden)

    S.J. Josiah

    2011-11-01

    Full Text Available The protective role of ethanolic extract of unripe pulp of Carica papaya (fruit, against potassiumbromate induced tissue damage in wistar rats was investigated. The animals were grouped into four groups (A, B, C, D of five rats. Group A was administered 1 mL of 0.25 M sucrose solution. 60 mg/kg of Potassium bromate KBrO3 was administered orally to rats in groups B, C and D. Groups C and D were pretreated with 250 and 500 mg/kg of the extracts for fourteen (14 days, respectively. The organ to body-weight ratio, total amino acid, total protein and malondialdeyde (MDA concentration in the brain, spleen, kidney, liver, and heart were colorimetrically measured as an assessment of the level of tissue damage. All the parameters studied increases significantly in all the tissues of rats group B. There was significant decrease in the organ-to-body weight ratio and total protein level in all the tissues investigated (p<0.05, when compared with Group B at both doses of the extract. The total protein level of the stomach had a drastic reduction at 500 mg/kg. Also, the Amino acid level of investigated tissues decreased significantly, while malondialdeyde levels decreased significantly in a dose dependent manner. These findings suggest that ethanolic extract of unripe pulp of Carica papaya may be protective against KBrO3 induced tissue damage in Wistar rats.

  17. Multiple linear regression model for bromate formation based on the survey data of source waters from geographically different regions across China.

    Science.gov (United States)

    Yu, Jianwei; Liu, Juan; An, Wei; Wang, Yongjing; Zhang, Junzhi; Wei, Wei; Su, Ming; Yang, Min

    2015-01-01

    A total of 86 source water samples from 38 cities across major watersheds of China were collected for a bromide (Br(-)) survey, and the bromate (BrO3 (-)) formation potentials (BFPs) of 41 samples with Br(-) concentration >20 μg L(-1) were evaluated using a batch ozonation reactor. Statistical analyses indicated that higher alkalinity, hardness, and pH of water samples could lead to higher BFPs, with alkalinity as the most important factor. Based on the survey data, a multiple linear regression (MLR) model including three parameters (alkalinity, ozone dose, and total organic carbon (TOC)) was established with a relatively good prediction performance (model selection criterion = 2.01, R (2) = 0.724), using logarithmic transformation of the variables. Furthermore, a contour plot was used to interpret the influence of alkalinity and TOC on BrO3 (-) formation with prediction accuracy as high as 71 %, suggesting that these two parameters, apart from ozone dosage, were the most important ones affecting the BFPs of source waters with Br(-) concentration >20 μg L(-1). The model could be a useful tool for the prediction of the BFPs of source water.

  18. New inorganic (an)ion exchangers with a higher affinity for arsenate and a competitive removal capacity towards fluoride, bromate, bromide, selenate, selenite, arsenite and borate

    KAUST Repository

    Chubar, Natalia

    2011-12-01

    Highly selective materials and effective technologies are needed to meet the increasingly stronger drinking water standards for targeted ionic species. Inorganic ion exchangers based on individual and mixed-metal hydrous oxides (or mixed adsorbents that contain inorganic ion exchangers in their composition) are adsorptive materials that are capable of lowering the concentrations of anionic contaminants, such as H 2AsO 4 -, H 3AsO 3, F -, Br -, BrO 3 -, HSeO 4 -, HSeO 3 - and H 3BO 3, to 10 μg/L or less. To achieve a higher selectivity towards arsenate, a new ion exchanger based on Mg-Al hydrous oxides was developed by a novel, cost-effective and environmentally friendly synthesis method via a non-traditional (alkoxide-free) sol-gel approach. The exceptional adsorptive capacity of the Mg-Al hydrous oxides towards H 2AsO 4 - (up to 200 mg[As]/gdw) is due to the high affinity of this sorbent towards arsenate (steep equilibrium isotherms) and its fast adsorption kinetics. Because of the mesoporous (as determined by N 2 adsorption and SEM) and layered (as determined by XRD and FTIR) structure of the ion-exchange material as well as the abundance of anion exchange sites (as determined by XPS and potentiometric titration) on its surface the material demonstrated very competitive (or very high) removal capacity towards other targeted anions, including fluoride, bromide, bromate, selenate, selenite, and borate. © 2011 IWA Publishing.

  19. DISSCUSS ON CONTROL TECHNOLOGIES FOR THE CONTENT OF BROMATE FROM OZONATION DISINFECTION BY-PRODUCT IN DRINKING WATER%饮用水中臭氧消毒副产物溴酸盐含量的控制技术探讨

    Institute of Scientific and Technical Information of China (English)

    张书芬; 王全林; 沈坚; 钟雄华

    2011-01-01

    The paper described the formation mechanism of bromate in the process of ozonation, and then studied control method to limit the bromated content in drinking water in the steps of pretreatment of raw water, controlment of bromate formation and removal of bromated.It is a feasible approach to adopt membrane separation technology (control of raw water conductivity and microbial content), ammonia treatment, combination of various disinfectants and using new disinfectant, optimization of ozone disinfection process and activated carbon adsorption technology to control the bromate content in drinking water.In order to get the balance of ozone, microorganisms and bromate, water characteristic, production capacity,enterprise size and running cost should be concerned.%在阐述臭氧化过程中溴酸盐的生成机理的前提下,从原水预处理、溴酸盐形成过程控制、溴酸盐形成后消除3个阶段来分析研究控制饮用水中溴酸盐含量的方法.经过探讨和实践表明,采用膜分离技术(控制原水电导率和微生物含量)、加氨、采用新型消毒剂和多种消毒剂组合使用、优化臭氧消毒工艺和活性炭吸附技术等是较为可行的控制途径.饮用水生产企业根据水源特点,生产能力,企业规模、运行成本等条件进行选择尝试,从而实现臭氧,微生物和溴酸盐之间的平衡.

  20. Possible participation of oxidative stress in causation of cell proliferation and in vivo mutagenicity in kidneys of gpt delta rats treated with potassium bromate

    International Nuclear Information System (INIS)

    Clarifying the participation of oxidative stress among possible contributing factors in potassium bromate (KBrO3)-induced carcinogenesis is of importance from the perspective of human health protection. In the present study, utilizing the antioxidative effects of α-tocopherol (α-TP) or sodium ascorbic acid (SAA) to attenuate oxidative stress, alterations in bromodeoxyuridine labeling indices (BrdU-LIs) and reporter gene mutations in kidneys of male and female gpt delta rats given KBrO3 were examined. Five male and female gpt delta rats in each group were given KBrO3 at a concentration of 500 ppm in the drinking water for 9 weeks, with 1% of α-TP or SAA administered in the diet from 1 week prior to the KBrO3 treatment until the end of the experiment. Increases in 8-hydroxydeoxyguanosine levels in kidney DNA of both sexes of rats given KBrO3 were significantly inhibited by SAA, but not α-TP. While BrdU-LIs in the proximal tubules of female rats were also significantly reduced by SAA, those in the males and gpt mutant frequencies in kidney DNA of both sexes were not affected by SAA or α-TP. Immunohistochemical and Western blot analyses for α2u-globulin strongly suggested that induction of cell proliferation observed in the males might primarily result from accumulation of this protein, independent of oxidative stress. The overall data indicated that while oxidative stress well correlates with induction of cell proliferation in females, its role in males and in generation of in vivo mutagenicity by KBrO3 in both sexes is limited

  1. Simultaneous determination of bromate, chlorite and haloacetic acids by two-dimensional matrix elimination ion chromatography with coupled conventional and capillary columns.

    Science.gov (United States)

    Teh, Hui Boon; Li, Sam Fong Yau

    2015-02-27

    A new, highly sensitive and reliable two-dimensional matrix elimination ion chromatography (IC) method was developed for simultaneous detection of bromate, chlorite and five haloacetic acids. This method combined the conventional IC in first dimension with capillary IC in the second dimension coupled with suppressed conductivity detection. The first dimension utilizes a high capacity column to partially resolve matrix from target analytes. By optimizing the cut window, the target analytes were selectively cut and trapped in a trap column through the use of a six-port valve, while the separated matrix were diverted to waste. The trapped target analytes were delivered on to the capillary column for further separation and detection. Temperature programming was used to improve selectivity in second dimension column to obtain complete resolution of the target analytes. Compared to the performance of one-dimensional IC, the two-dimensional approach resulted in a significant increase in sensitivity for all target analytes with limit of detection ranging from 0.30 to 0.64μg/L and provided more reliable analysis due to second column confirmation. Good linearity was obtained for all the target analytes with correlation coefficients >0.998. The proposed method was successfully applied to the determination of oxyhalides and haloacetic acids in various matrices with recoveries ranging from 90 to 116% and RSD less than 6.1%. The method allows direct injection of samples and the use of columns with different selectivity, thus significantly reduces the level of false positive results. The method is fully automated and simple, making it practical for routine monitoring of water quality. The satisfactory results also demonstrated that the two-dimensional matrix elimination method coupled with capillary IC is a promising approach for detection of trace substances in complex matrices.

  2. Cerium incorporated MCM-48 (Ce-MCM-48) as a catalyst to inhibit bromate formation during ozonation of bromide-containing water: Efficacy and mechanism.

    Science.gov (United States)

    Li, Weiwei; Lu, Xiaowei; Xu, Ke; Qu, Jiuhui; Qiang, Zhimin

    2015-12-01

    The composite mesoporous sieve Ce-MCM-48 (cerium incorporated MCM-48) with different Si/Ce molar ratios were synthesized hydrothermally and characterized with X-ray diffraction, X-ray photoelectron spectroscopy, BET surface area, and pHpzc. Results indicate that Ce-MCM-48, especially with a Si/Ce molar ratio of 66 (i.e., Ce66-MCM-48), could significantly inhibit bromate (BrO3(-)) formation during ozonation of Br(-)-containing water, achieving 91% of inhibition efficiency at pH 7.6 and 25 °C. An acidic or alkaline pH decreased the inhibition efficiency of Ce66-MCM-48 to some extent, but reaction temperature ranging from 15 to 30 °C had no significant impact. By comparing the bromine mass balance, aqueous O3 decomposition, and newly formed H2O2 between O3 and O3/Ce66-MCM-48 processes, the inhibition mechanism was proposed: Ce66-MCM-48 promoted aqueous O3 decomposition to generate hydroxyl radicals (OH) that could merge into H2O2, so the oxidative transformation of Br(-) and HOBr/OBr(-) by O3 and OH was primarily suppressed. The catalytic ability of Ce66-MCM-48 was continuously regenerated through the circulating reactions between Ce(III) and Ce(IV) occurring on the catalyst surface. Besides its inhibition on BrO3(-) formation, Ce66-MCM-48 could also enhance the degradation of refractory organic micropollutants. Because of these distinct merits, Ce66-MCM-48 has potential applications to water treatment by ozone.

  3. Ion chromatographic determination of trace iodate, chlorite, chlorate, bromide, bromate and nitrite in drinking water using suppressed conductivity detection and visible detection.

    Science.gov (United States)

    Binghui, Zhu; Zhixiong, Zhong; Jing, Yao

    2006-06-16

    An ion chromatography method for the simultaneous determination of trace iodate, chlorite, chlorate, bromide, bromate and nitrite in drinking water has been developed using an anion-exchange column and the suppressed conductivity detector, followed by post-column addition of reagent to enhance visible absorbance detection of ions. A high capacity anion exchange Ion Pac9-HC column (250 mm x 4 mm I.D.) was used. Eight millimole per liter sodium carbonate was used as eluent, an auto-suppression external water mode was selected, 0.5 g/l o-dianisidine.2HCl (ODA)+4.5 g/l KBr+25% methanel+5.6% nitric acid was used as post-column reagent. The post-column reaction (PCR) temperature was at 60 degrees C, and the visible absorbance detected wavelength at 450 nm. The sample's pH and coexist anions had no influence on determination. The method enjoyed a wide linear range and a good linear correlation coefficient (r>0.999). The method detection limits were between 0.023 and 2.0 microg/l. The average recoveries ranged from 87.5 to 110.0%, and the relative standard deviations (RSD) were in the range of 1.1-4.6%. The analytical results by the method of post-column addition of reagent to enhance visible absorbance detection of anions was compared with that of the suppressed conductivity detection, and the former was proved to be better in sensitivity and selectivity. The results showed that this method was accurate, sensitive and might be good for application and suitable for trace analysis at the level of mug/l.

  4. Photo-reduction of bromate in drinking water by metallic Ag and reduced graphene oxide (RGO) jointly modified BiVO4 under visible light irradiation.

    Science.gov (United States)

    Chen, Fei; Yang, Qi; Zhong, Yu; An, Hongxue; Zhao, Jianwei; Xie, Ting; Xu, Qiuxiang; Li, Xiaoming; Wang, Dongbo; Zeng, Guangming

    2016-09-15

    Bromate (BrO3(-)), an oxyhalide disinfection by-product (DBP) in drinking water, has been demonstrated to be carcinogenic and genotoxic. In the current work, metallic Ag and reduced graphene oxide (RGO) co-modified BiVO4 was successfully synthesized by a stepwise chemical method coupling with a photo-deposition process and applied in the photo-reduction of BrO3(-) under visible light irradiation. In this composite, metallic Ag acted as an electron donor or mediator and RGO enhanced the BrO3(-) adsorption onto the surface of catalysts as well as an electron acceptor to restrict the recombination of photo-generated electron-hole pairs. The Ag@BiVO4@RGO composite exhibited greater photo-reduction BrO3(-) performance than pure BiVO4, Ag@BiVO4 and RGO@BiVO4 under identical experimental conditions: initial BrO3(-) concentration 150 μg/L, catalyst dosage 0.5 g/L, pH 7.0 and visible light (λ > 420 nm). The photoluminescence spectra (PL), electron-spin resonance (ESR), photocurrent density (PC) and electrochemical impedance spectroscopy (EIS) measurements indicated that the modified BiVO4 enhanced the photo-generated electrons and separated the electron-hole pairs. The photocatalytic reduction efficiency for BrO3(-) removal decreased with the addition of electron quencher K2S2O8, suggesting that electrons were the primary factor in this photo-reduction process. The declining photo-reduction efficiency of BrO3(-) in tap water should attribute to the consumption of photo-generated electrons by coexisting anions and the adsorption of dissolved organic matter (DOM) on graphene surface. The overall results indicate a promising application potential for photo-reduction in the DBPs removal from drinking water. PMID:27311108

  5. Cerium incorporated MCM-48 (Ce-MCM-48) as a catalyst to inhibit bromate formation during ozonation of bromide-containing water: Efficacy and mechanism.

    Science.gov (United States)

    Li, Weiwei; Lu, Xiaowei; Xu, Ke; Qu, Jiuhui; Qiang, Zhimin

    2015-12-01

    The composite mesoporous sieve Ce-MCM-48 (cerium incorporated MCM-48) with different Si/Ce molar ratios were synthesized hydrothermally and characterized with X-ray diffraction, X-ray photoelectron spectroscopy, BET surface area, and pHpzc. Results indicate that Ce-MCM-48, especially with a Si/Ce molar ratio of 66 (i.e., Ce66-MCM-48), could significantly inhibit bromate (BrO3(-)) formation during ozonation of Br(-)-containing water, achieving 91% of inhibition efficiency at pH 7.6 and 25 °C. An acidic or alkaline pH decreased the inhibition efficiency of Ce66-MCM-48 to some extent, but reaction temperature ranging from 15 to 30 °C had no significant impact. By comparing the bromine mass balance, aqueous O3 decomposition, and newly formed H2O2 between O3 and O3/Ce66-MCM-48 processes, the inhibition mechanism was proposed: Ce66-MCM-48 promoted aqueous O3 decomposition to generate hydroxyl radicals (OH) that could merge into H2O2, so the oxidative transformation of Br(-) and HOBr/OBr(-) by O3 and OH was primarily suppressed. The catalytic ability of Ce66-MCM-48 was continuously regenerated through the circulating reactions between Ce(III) and Ce(IV) occurring on the catalyst surface. Besides its inhibition on BrO3(-) formation, Ce66-MCM-48 could also enhance the degradation of refractory organic micropollutants. Because of these distinct merits, Ce66-MCM-48 has potential applications to water treatment by ozone. PMID:26072989

  6. Formation of bromate and halogenated disinfection byproducts during chlorination of bromide-containing waters in the presence of dissolved organic matter and CuO

    KAUST Repository

    Liu, Chao

    2015-12-02

    Previous studies showed that significant bromate (BrO3-) can be formed via the CuO-catalyzed disproportionation of hypobromous acid (HOBr) pathway. In this study, the influence of CuO on the formation of BrO3- and halogenated disinfection byproducts (DBPs) (e.g., trihalomethanes, THMs and haloacetic acids, HAAs) during chlorination of six dissolved organic matter (DOM) isolates was investigated. Only in the presence of slow reacting DOM (from treated Colorado River water, i.e., CRW-BF-HPO), significant BrO3- formation is observed, which competes with bromination of DOM (i.e., THM and HAA formation). Reactions between HOBr and 12 model compounds in the presence of CuO indicates that CuO-catalyzed HOBr disproportionation is completely inhibited by fast reacting phenols, while it predominates in the presence of practically unreactive compounds (acetone, butanol, propionic, and butyric acids). In the presence of slow reacting di- and tri-carboxylic acids (oxalic, malonic, succinic, and citric acids), BrO3- formation varies, depending on its competition with bromoform and dibromoacetic acid formation (i.e., bromination pathway). The latter pathway can be enhanced by CuO due to the activation of HOBr. Therefore, increasing CuO dose (0-0.2 g L-1) in a reaction system containing chlorine, bromide, and CRW-BF-HPO enhances the formation of BrO3-, total THMs and HAAs. Factors including pH and initial reactant concentrations influence the DBP formation. These novel findings have implications for elevated DBP formation during transportation of chlorinated waters in copper-containing distribution systems.

  7. Photo-reduction of bromate in drinking water by metallic Ag and reduced graphene oxide (RGO) jointly modified BiVO4 under visible light irradiation.

    Science.gov (United States)

    Chen, Fei; Yang, Qi; Zhong, Yu; An, Hongxue; Zhao, Jianwei; Xie, Ting; Xu, Qiuxiang; Li, Xiaoming; Wang, Dongbo; Zeng, Guangming

    2016-09-15

    Bromate (BrO3(-)), an oxyhalide disinfection by-product (DBP) in drinking water, has been demonstrated to be carcinogenic and genotoxic. In the current work, metallic Ag and reduced graphene oxide (RGO) co-modified BiVO4 was successfully synthesized by a stepwise chemical method coupling with a photo-deposition process and applied in the photo-reduction of BrO3(-) under visible light irradiation. In this composite, metallic Ag acted as an electron donor or mediator and RGO enhanced the BrO3(-) adsorption onto the surface of catalysts as well as an electron acceptor to restrict the recombination of photo-generated electron-hole pairs. The Ag@BiVO4@RGO composite exhibited greater photo-reduction BrO3(-) performance than pure BiVO4, Ag@BiVO4 and RGO@BiVO4 under identical experimental conditions: initial BrO3(-) concentration 150 μg/L, catalyst dosage 0.5 g/L, pH 7.0 and visible light (λ > 420 nm). The photoluminescence spectra (PL), electron-spin resonance (ESR), photocurrent density (PC) and electrochemical impedance spectroscopy (EIS) measurements indicated that the modified BiVO4 enhanced the photo-generated electrons and separated the electron-hole pairs. The photocatalytic reduction efficiency for BrO3(-) removal decreased with the addition of electron quencher K2S2O8, suggesting that electrons were the primary factor in this photo-reduction process. The declining photo-reduction efficiency of BrO3(-) in tap water should attribute to the consumption of photo-generated electrons by coexisting anions and the adsorption of dissolved organic matter (DOM) on graphene surface. The overall results indicate a promising application potential for photo-reduction in the DBPs removal from drinking water.

  8. Micronucleus test of varying amounts of potassium bromate (KBrO3) on the meristematic cells of Allium cepa var. aggregatum root tips

    International Nuclear Information System (INIS)

    Four hundred twenty onion bulbs of the multiplier variety Allium cepa var. aggregatum were used as test materials to assay the micronucleus induction capacity of potassium bromate doses of 0, 5, 10, 25, 50, 75, and 100 parts per million. Microscopic analyses were done using onion root tips prepared according to a modified technique of Medina (1994). These analyses were done on root tips taken from onions grown in KBrO3 for three days and for five days. The study was conducted following a completely randomized design and the data were statistically analyzed using a non-parametric equivalent of the analysis of variance. A significant amount of micronucleated cells (MCN) were found among treated onions compared with the almost non-occurrence in the control groups (0 ppm). The Kruskal-Wallis H-test and the Wilcoxon two-samples tests revealed significant differences among treatment means and that a significant increase in the number of MCN occurs as the dose of KBr03 increased in both day experiments. Results from the higher doses of 50, 75, and 100 ppm were found to be significantly the same for the day 3 experiments while those of the day 5 higher doses are characterized by lack of clear cellular and nuclear outline such that scoring is difficult. Differences in MCN averages for the day 3 and 5 experiments appear to be insignificant. However, day 3 results show averages that are more significantly different from each other. These prove that the MCN can be used as an efficient and time-saving parameter for the allium test of chemicals with chromosome breaking capacities. (Author)

  9. Low-level bromate analysis in drinking water by ion chromatography with optimized suppressed conductivity cell current followed by a post-column reaction and UV/Vis detection.

    Science.gov (United States)

    Fotsing, Marcellin; Barbeau, Benoit; Prevost, Michele

    2011-01-01

    In the present work, a high capacity anion exchange column was used to efficiently and simultaneously separate traces of oxyhalide disinfection byproducts (DBP) anions and bromide by an ion chromatography system followed by a post-column reaction (PCR). The PCR generates in situ hydroiodic (HI) acid from the excess of potassium iodate that combines with bromate from the column effluent to form the triiodide anion detectable by UV/Vis absorbance at 352 nm. The suppressed conductivity cell current was optimized at 70 mA, with a flow rate of 1.0 mL/min and a 9 mM carbonate eluent. Its performance was investigated on a trace-level determination of bromate in ozonated municipal and bottled drinking water. Based on ozonated municipal drinking water matrix, the method detection limit of 0.27 μg BrO(-)(3)/L was evaluated with the Method Quantification Limit (MQL) of 0.89 μg BrO(-)(3)/L. However, in ultrapure water, a MDL of 0.015 μg BrO(-)(3)/L and a MRL of 0.052 μg BrO(-)(3)/L were achieved. The recovery for spiked municipal samples was in the range of 90%-115%.

  10. Dinâmica complexa no sistema bromato/hipofosfito/acetona/manganês e ferroína Complex Dynamics in the bromate/hypophosphite/acetone/manganese and ferroin system

    Directory of Open Access Journals (Sweden)

    Gustavo Tokoro

    2007-01-01

    Full Text Available New chemical systems have been recently designed for the study of complex phenomena such as oscillatory dynamics in the temporal domain and spatiotemporal pattern formation. Systems derived from oscillators based on the chemistry of bromate are the most extensively studied, with the celebrated Belousov-Zhabotinsky (BZ reaction being the most popular example. Problems such as the formation of bubbles (CO2 and solid precipitate in the course of the reaction and the occurrence of simply short-lived oscillations under batch conditions are very common and, in some cases, compromise the use of some of these systems. It is investigated in this paper the dynamic behavior of the bromate/hypophosphite/acetone/dual catalyst system, which has been sugested as an interesting alternative to circumvent those inconvenients. In this work, manganese and ferroin are employed as catalysts and the complete system (BrO3-/H2PO2-/acetone/Mn(II-ferroin is studied under batch conditions. Temporal symmetry breaking was studied in a reactor under agitation by means of simultaneous records of the potential changes of platinum and Ag/AgBr electrodes, both measured versus a reversible hydrogen electrode. Additionally, spatio-temporal formation of target patterns and spiral waves were obtained when the oscillating mixture was placed in a quasi two-dimensional reactor.

  11. Determination of Trace Nitrite and Bromate in Pure Water Samples by Ion Chroma Tography%离子色谱法测定饮用水中亚硝酸盐和溴酸盐含量的变化

    Institute of Scientific and Technical Information of China (English)

    李舒

    2011-01-01

    [目的]探讨饮用水中亚硝酸盐(NO2-)和溴酸盐(BrO3-)含量的变化.[方法]利用ICS-2000离子色谱法检测了3种饮用水中亚硝酸盐和溴酸盐在不同条件下的含量.[结果]在自来水、桶装纯净水、桶装矿泉水3种水中,亚硝酸盐含量随时间的增加有所增加,加热也未降低亚硝酸盐含量;纯水、自来水中未检测出溴酸盐,桶装矿泉水中测得的溴酸盐均随着时间的增加而增加,加热后能够较大程度上降低桶装矿泉水中溴酸盐的浓度.该方法检测的NO2-浓度在0~2 mg/L范围内有良好的线性关系(r=0.999 95),最小检测值为0.000 1 mg/L,实样加标回收率在97.34% ~ 108.61%;BrO3-浓度在0~2 mg/L范围内也有良好的线性关系(r=0.999 97),最小检测值为0.000 2 mg/L,实样加标回收率在95.93%~101.04%.[结论]该方法精密度高、操作简便、易推广.%[Objective] Changes of trace nitrite and bromate in pure water samples were explored. [ Method ] Contents of trace nitrite and bromate in three kinds of pure water samples under different conditons were determined by using ICS-2000 ion chromatography. [Result]The contents of nitrite in three samples of tap water,bottled water and bottled mineral water increased with the increase of time,but didn' t decrease under the treatment of heating. There was no bromate in pure water and tap water; the content of bromate in bottled mineral water also increased with the increase of time,and could be decreased to a much greater extent after healing. Nitrite showed good linear relationship within 0-2 mg/L (r = 0.999 95); the minimum detection value was 0.000 1 mg/L; and the sample standard addition was 97.34% - 108. 61%. Bromate also showed good linear relationship within 0 ~ 2 mg/L ( r = 0.999 97); the minimum detection value was 0.000 2 mg/L; and the sample standard addition was 95.93% ~ 101.04%. [ Conclusion]The method has high accuracy,simple operation and application.

  12. Electrosorption of Os(III)-complex at single-wall carbon nanotubes immobilized on a glassy carbon electrode: Application to nanomolar detection of bromate, periodate and iodate

    Energy Technology Data Exchange (ETDEWEB)

    Salimi, Abdollah [Department of Chemistry, University of Kurdistan, P.O. Box 416, Sanandaj (Iran, Islamic Republic of); Research Center for Nanotechnology, University of Kurdistan, P.O. Box 416, Sanandaj (Iran, Islamic Republic of)], E-mail: absalimi@uok.ac.ir; Kavosi, Begard [Department of Chemistry, University of Kurdistan, P.O. Box 416, Sanandaj (Iran, Islamic Republic of); Department of Chemistry, Arak University, P.O. Box, 38156-879 Arak (Iran, Islamic Republic of); Babaei, Ali [Department of Chemistry, Arak University, P.O. Box, 38156-879 Arak (Iran, Islamic Republic of); Hallaj, Rahman [Department of Chemistry, University of Kurdistan, P.O. Box 416, Sanandaj (Iran, Islamic Republic of)

    2008-06-16

    A simple procedure was developed to prepare a glassy carbon electrode modified with single-wall carbon nanotubes (SWCNTs) and Os(III)-complex. The glassy carbon (GC) electrode modified with CNTs was immersed into Os(III)-complex solution (direct deposition) for a short period of time (60 s). 1,4,8,12-Tetraazacyclotetradecane osmium(III) chloride, (Os(III)LCl{sub 2}).ClO{sub 4}, irreversibly and strongly adsorbed on SWCNTs immobilized on the surface of GC electrode. Cyclic voltammograms of the Os(III)-complex-incorporated-SWCNTs indicate a pair of well defined and nearly reversible redox couple with surface confined characteristic at wide pH range (1-8). The surface coverage ({gamma}) and charge transfer rate constant (k{sub s}) of the immobilized Os-complex on SWCNTs were 3.07 x 10{sup -9} mol cm{sup -2}, 5.5 ({+-}0.2) s{sup -1}, 2.94 x 10{sup -9} mol cm{sup -2}, 7.3 ({+-}0.3) s{sup -1} at buffer solution with pH 2 and 7, respectively, indicate high loading ability of SWCNTs for Os(III) complex and great facilitation of the electron transfer between electroactive redox center and carbon nanotubes immobilized on the electrode surface. Modified electrodes showed higher electrocatalytic activity toward reduction of BrO{sub 3}{sup -}, IO{sub 3}{sup -} and IO{sub 4}{sup -} in acidic solutions. The catalytic rate constants for catalytic reduction bromate, periodate and iodate were 3.79 ({+-}0.2) x 10{sup 3}, 7.32 ({+-}0.2) x 10{sup 3} and 1.75 ({+-}0.2) x 10{sup 3} M{sup -1} s {sup -1}, respectively. The hydrodynamic amperometry of rotating modified electrode at constant potential (0.3 V) was used for nanomolar detection of selected analytes. Excellent electrochemical reversibility of the redox couple, good reproducibility, high stability, low detection limit, long life time, fast amperometric response time, wide linear concentration range, technical simplicity and possibility of rapid preparation are great advantage of this sensor.

  13. 感潮珠江原水臭氧氧化副产物BrO3-预测模型的建立%Modeling of bromate formation during ozonation process of surface water in the Pearl River Basin affected by seawater intrusion

    Institute of Scientific and Technical Information of China (English)

    胡冰; 吴纯德; 张之琳; 胡彩霞; 梁佳莉; 梁国建; 刘吕刚

    2013-01-01

    以珠江流域西江中山段的感潮原水为对象,模拟其臭氧预处理、常规处理和臭氧活性炭处理,考察原水预、主臭氧对应投加量时溴酸盐生成情况,构建了预、主臭氧溴酸盐生成经验预测模型.结果表明,在预臭氧过程中,高的DOC、O3及Br-浓度,会增加溴酸盐的生成量,升高pH,提高NH3-N及IC有利于抑制溴酸盐的形成;在主臭氧过程中,升高pH,提高O3及Br-浓度,会增加溴酸盐的生成量,而高的DOC、NH3-N及IC会降低溴酸盐的形成风险.所建模型预测实际水样,发现预、主臭氧预测模型预测误差分别为33.72%和13.22%.%In this study, by selecting the raw water of Xijiang Zhongshan section of the Pearl River Basin affected by seawater intrusion and simulating the processes of preozonation, general treatment, postozonation and GAC, the bromate formation of different ozone dosages and modeling of bromate formation during preozonation and later ozonation process was studied. The results show that during preozonation process, high concentrations of DOC, O3 and Br- in raw water, lead to more generation of bromate, while pH,NH3-N and IC can suppress bromate formation under cetain conditions. During postozonation process, bromate concentration increases increases of pH value, ozone and bromine concentration, but high concentrations of DOC, NH3-N and IC reduce the risk of the bromate formation. For predicting water samples, the forecast errors of the formation modelings during preozonation process and later qzonation process are 33. 72% and 13. 22%, respectively.

  14. Seguiment i interpretació de la degradació de contaminants bromats mitjançant tècniques cromatogràfiques, espectroscòpiques i quimiomètriques

    OpenAIRE

    Mas Garcia, Silvia

    2012-01-01

    [cat]Aquesta Tesi Doctoral presenta l’estudi de degradació de dues classes de retardants de flama bromats (els difenilèters polibromats (PBDEs) i els bromofenols) mitjançant tècniques espectroscòpiques, cromatogràfiques i quimiomètriques. S’ha estudiat dos tipus de degradació: la fotodegradaciói la biodegradació. A més dels estudis específics d’aquests processos, s’ha treballat en la revisió de metodologia existent i en el desenvolupament de nous procediments per a la interpretació d’informac...

  15. 饮用水中的亚氯酸盐、氯酸盐和溴酸盐的离子色谱测定法%Determination of Chlorite ,Chlorate and Bromate in Drinking Water by Ion Chromatography

    Institute of Scientific and Technical Information of China (English)

    周虹; 周小新

    2009-01-01

    Objective To develop an ion chromatography (IC) for simultaneous determination of chlorite, chlorate and bromate in drinking water. Methods The IC separation was carried out with the IonPAC AS23 column by using 4.5 mmol/L Na_2CO_3-0.8 mmol/L NaHCO_3 at the flow rate of 1.0 ml/min. The injection volume was 250 μl.the temperature of conductivity detector cell and column were 30 ℃ and 35 ℃, respectively. The pressure upon the bottle of mobile phase was 40 kPa. The current of auto-regenerating suppressor was 25 mA. Results The results showed that in the range of 0 to 1 000 mg/L, the calibration equation for chlorite was y=0.009 6+1.600 0 x (r=0.999 3),for bromate was y=0.003 2+3.184 7 x (r=0.999 9),for chlorate was y= 0.001 8+1.788 9 x(r=0.999 9).The detection limit of chlorite,chlorate and bromate were all 5 μg/ L,the recovery rates were 89.0% -108.0% and the relative standard deviations (RSD) were 0.21%-2.70%. Conclusion The method is simple,fast,accurate, sensitive, little interference and is applicable to the simultaneous determination of chlorite, chlorate and bromate in drinking water.%目的 建立同时测定饮用水中亚氯酸盐、氯酸盐和溴酸盐的离子色谱法.方法 选择IonPacAS23色谱柱,淋洗液为4.5mmol/L Na_2CO_3-0.8 mmol/L NaHCO_3,流速为1.0 ml/min,进样量为250 μl,电导检测池温度为30℃,色谱柱温度为35 ℃,流动相瓶加压为40 kPa,抑制器抑制模式为自动再生模式,抑制器电流为25 mA.结果 在0~1 000.0 mg/L范围内,亚氯酸盐的线性方程为:y=0.009 6+1.600 0x,r=0.999 3,检出限为5μg/L;溴酸盐的线性方程为:y=0.003 2+3.184 7x,r=0.999 9,检出限为5μg/L;氯酸盐的线性方程为:y=0.001 8+1.788 9x,r=0.999 9,检出限为5μg/L.加标回收试验结果显示,该方法的平均回收率为89.0%~108.0%,RSD为0.21%~2.70%.结论 该法操作简单、快速、准确,灵敏度高、干扰少,适用于饮用水中亚氯酸盐、氯酸盐和溴酸盐的同时测定.

  16. A Preliminary Study of the Formation of Bromate By-products During Ozone Disinfection in Rural Drinking Water Supply%农村供水臭氧消毒副产物溴酸盐生成的初步研究

    Institute of Scientific and Technical Information of China (English)

    贾燕南; 魏向辉; 刘文朝

    2013-01-01

    臭氧消毒近年来为各地农村供水工程所广泛采用,但其带来的副产物溴酸盐超标问题却没有引起足够的重视.对北京若干区县的实际水样进行臭氧投加试验,考察了副产物溴酸盐的生成情况,探讨了臭氧消毒的适用性.结果表明:北京地区地下水采用臭氧消毒时溴酸盐超标的风险较高,建议在选择臭氧消毒前首先对原水进行臭氧投加试验,并考察生成溴酸盐的浓度水平;臭氧投加方式对于溴酸盐生成量的影响较大.%Ozone disinfection is widely used in many rural drinking water supply projects. However, more attention should be paid to the fact that the bromate by-product formed may be over standard in the disinfection process. In this paper, ozone adding experiments towards groundwater samples of different rural drinking water projects from various towns in Beijing are developed, and the bromate formation of the water samples is observed. Results show that risk of bromate of theses groundwater samples from Beijing exceeding the standard values is rather high after ozone disinfection. Besides, ozone dosing methods has a significant effect on formation of bromate.

  17. Validação do método de determinação simultânea dos íons brometo e bromato por cromatografia iônica em águas de consumo humano Validation of simultaneous determination of bromides and bromates by ion chromatography in drinking water

    Directory of Open Access Journals (Sweden)

    Maria Edite Pinto Gonçalves

    2004-06-01

    Full Text Available European Directive (98/83/CE, compulsory after 2008, states that bromate in drinking water must be controlled at levels below 10 mg L-1. Supporting implementation of the Directive, the European Comission has established project SMT4-CT96 2134, in collaboration with various european institutions, aiming at the identification of the interferents to the current analytical method (Ionic Chromatography with Conductimetric Detection - IC/CD, their removal and the automation of pre-treatment and injection steps, as well as the development of alternative methods. EPAL, responsible for the water supply to a great deal of Portuguese regions, has taken steps to meet these requirements. Although not part of such project, this work (the result of a project conducted under a protocol of collaboration between EPAL SA and FCUL - Faculty of Sciences, University of Lisbon, reports on studies of usefulness to laboratories planning to monitor bromate in ozone treated waters, in conditions different from those described in EPA 300.1. Simultaneous determination of bromide is justified by its role as bromate precursor.

  18. Determination of Chlorite, Bromate, Chlorate in Surface Water and Drinking Water by Ion Chromatography%离子色谱法测定地表水和饮用水中亚氯酸盐、溴酸盐和氯酸盐

    Institute of Scientific and Technical Information of China (English)

    窦艳艳; 杨丽莉; 徐荣; 胡恩宇

    2013-01-01

    采用KOH梯度淋洗离子色谱法测定地表水和饮用水中ClO2-、BrO3-和ClO3-,在试验确定的条件下,3种离子与F-、Cl-、NO2-、NO3-、SO2-4、Br-、I-等7种离子分离度良好。 ClO2-、BrO3-、ClO3-在50.0μg/L~1000μg/L范围内线性良好,检出限分别为5.2μg/L、8.9μg/L、7.6μg/L,环境水样加标平行测定的RSD分别为2.1%~5.4%、4.1%~5.4%、2.5%~4.8%,两个质量浓度水平加标的平均回收率分别为93.7%~96.5%、90.3%~94.8%、98.7%~111%。%An ion chromatography method for determining chlorite , bromate and chlorate in surface water and drinking water was studied .The separation of the anions was achieved on an IonPac AS 19 Column with KOH as eluent, the chlorite, bromate, chlorate and other 7 kinds of anions could be well separated and determined within 25 min by employing a concentration gradient .The method has good linearity during the concentration 50.0 μg/L ~1 000 μg/L.The method detection limits of chlorite, bromate and chlorate was 5.2 μg/L, 8.9 μg/L and 7.6 μg/L, respectively.The RSD of the samples were 2.1%~5.4% ( chlorite), 4.1%~5.4%(bromate), and 2.5%~4.8% (chlorate).The recoveries of chlorite, bromate and chlorate in water samples were 93.7%~96.5%, 90.3%~94.8%and 98.7%~111%.

  19. 生活饮用水中溴酸盐、氯酸盐和亚氯酸盐的离子色谱测定法%Determination of bromate, chlorate, and chlorite in drinking water by ion chromatography

    Institute of Scientific and Technical Information of China (English)

    孙卫明; 孙建飞; 王权帅

    2013-01-01

    [ Objective ] To establish a method for determination of bromate, chlorate, and chlorite in drinking water by ion chroma-tography. [ Methods] ] After filtration by 0.22 μm membrane filter, The water samples were put into the ion exchange system of ion chromatography, with the potassium hydroxide eluent. Different ions separated with the different affinity in one separation column and determined quantitatively by the external standard method. [ Results] Recoveries of bromate were 87.5% to 116.0% , and the relative standard deviation (RSD) was 69% ; recoveries of chlorate were 86. 8% to 99.0% , with RSD of 1. 21% ; recoveries of chlorite of 80.1% to 87.0% , with the RSD of 0.93% and the correlation coefficients of all 3 ions were r >0.999 0. [ Conclusion] This method is simple, rapid, can obtain satisfactory separation, with high sensitivity and precision. Also, the recovery meets the methodological requirements. Above all, this method is entirely suitable for the simultaneous determination of bromate, chlorate, and chlorite in drinking water.%目的 建立离子色谱法测定生活饮用水中有溴酸盐、氯酸盐、亚氯酸盐的检测方法.方法 水样经0.22 μm滤膜过滤后,随氢氧化钾淋洗液进入离子色谱的离子交换系统.根据分离柱对不同离子的亲和力不同进行分离,外标法定量.结果 溴酸盐回收率为87.5% ~ 116.0%,相对标准偏差为2.69%;氯酸盐回收率为86.8%~ 99.0%,相对标准偏差为1.21%;亚氯酸盐回收率为80.1% ~ 87.0%,相对标准偏差为0.93%.以上3个项目相关系数均大于0.999 0.结论 该方法检测速度快,样品处理简便,能获得满意的分离效果,具有较高的灵敏度和精密度,回收率也满足方法学要求,完全适合于生活饮用水中有溴酸盐、氯酸盐、亚氯酸盐的同时测定.

  20. Catalytic Spectrophotometric Determination of Formaldehyde in Shrimp Samples with Potassium Bromate-two Cresol Orange System%溴酸钾-二甲酚橙催化褪色光度法测定虾仁中甲醛含量

    Institute of Scientific and Technical Information of China (English)

    熊海涛

    2012-01-01

    A new catalytic spectrophotometric method was developed for the determination of formaldehyde based on its catalytic effect on the oxidation reactions of two cresol orange by potassium bromate in phosphoric acid medium.And the fading obeyed Lambert-Beer law with the concentration of formaldehyde in a certain range.Under the optimal condition,the linear range of the determination for formaldehyde was 0.05~0.80 μg/mL with a detection limit of 0.013 μg/mL.And the detection recovery was from 97.5%~105%.The method could be used to determine formaldehyde content in shrimp samples with satisfactory results.%研究发现,在磷酸介质中,甲醛可以在一定温度下催化溴酸钾氧化二甲酚橙使其褪色,且褪色程度(ΔA)与甲醛的浓度在一定的范围内符合朗伯-比尔定律,据此建立了催化光度法测定甲醛含量的新方法。在最优的试验条件下,方法的线性范围为0.05~0.80μg/mL,检出限为0.013μg/mL,回收率在95%~110%之间。可用于虾仁中甲醛含量的测定,其效果令人满意。

  1. 溴酸钾-基橙-铁试剂-(V)体系催化光度法测定痕量钒%A modified spectrophotometric determination of vanadium by catalysis of the methyl orange-tiron-bromate reaction

    Institute of Scientific and Technical Information of China (English)

    杨武; 张煊; 管飞

    2000-01-01

    讨论了在钛铁试剂活化下钒催化溴酸钾氧化甲基橙的最佳反应条件,建立了测定钒的新方法.在0.1mol·L-1H2SO4溶液中,506nm处监测反应,可测定0.1~100.0ng·mL-1范围的钒.方法检测下限可达30pg·mL-1,比文献方法提高了30余倍.用于铝合金及食品样中钒的测定,结果满意.%Conditions are described for improving the speed and sensitivity of a catalytic determination of vanadium.The reaction of methyl orange with potassium bromate using tiron as an activator at 0.1 mol·L-1 sulfuric acid and spectrophotometric measurement at 506 nm are recommended.Reagent concentration,reaction temperature and pH were studied in detail.The calibration curves are obtained over the range 0.1~100.0 ng·mL-1 of vanadium by fixed-time method and the detection limit was down to 30pg·mL-1,which was about 30 times better than the previous methods.The improved method was applied to determination of vanadium in aluminum alloy and food samples with satisfactory results.

  2. Immobilization of [Cu(bpy){sub 2}]Br{sub 2} complex onto a glassy carbon electrode modified with {alpha}-SiMo{sub 12}O{sub 40}{sup 4-} and single walled carbon nanotubes: Application to nanomolar detection of hydrogen peroxide and bromate

    Energy Technology Data Exchange (ETDEWEB)

    Salimi, Abdollah [Department of Chemistry, University of Kurdistan, P.O. Box 416, Sanandaj (Iran, Islamic Republic of); Research Center for Nanotechnology, University of Kurdistan, P.O. Box 416, Sanandaj (Iran, Islamic Republic of)], E-mail: absalimi@uok.ac.ir; Korani, Aazam; Hallaj, Rahman; Khoshnavazi, Roshan [Department of Chemistry, University of Kurdistan, P.O. Box 416, Sanandaj (Iran, Islamic Republic of); Hadadzadeh, Hasan [Department of Chemistry, Isfahan University of Technology, Isfahan 84156-83111 (Iran, Islamic Republic of)

    2009-03-02

    A simple procedure has been used for preparation of modified glassy carbon electrode with carbon nanotubes and copper complex. Copper complex [Cu(bpy){sub 2}]Br{sub 2} was immobilized onto glassy carbon (GC) electrode modified with silicomolybdate, {alpha}-SiMo{sub 12}O{sub 40}{sup 4-} and single walled carbon nanotubes (SWCNTs){sub .} Copper complex and silicomolybdate irreversibly and strongly adsorbed onto GC electrode modified with CNTs. Electrostatic interactions between polyoxometalates (POMs) anions and Cu-complex, cations mentioned as an effective method for fabrication of three-dimensional structures. The modified electrode shows three reversible redox couples for polyoxometalate and one redox couple for Cu-complex at wide range of pH values. The electrochemical behavior, stability and electron transfer kinetics of the adsorbed redox couples were investigated using cyclic voltammetry. Due to electrostatic interaction, copper complex immobilized onto GC/CNTs/{alpha}-SiMo{sub 12}O{sub 40}{sup 4-} electrode shows more stable voltammetric response compared to GC/CNTs/Cu-complex modified electrode. In comparison to GC/CNTs/Cu-complex the GC/CNTs/{alpha}-SiMo{sub 12}O{sub 40}{sup 4-} modified electrodes shows excellent electrocatalytic activity toward reduction H{sub 2}O{sub 2} and BrO{sub 3}{sup -} at more reduced overpotential. The catalytic rate constants for catalytic reduction hydrogen peroxide and bromate were 4.5({+-}0.2) x 10{sup 3} M{sup -1} s{sup -1} and 3.0({+-}0.10) x 10{sup 3} M{sup -1} s{sup -1}, respectively. The hydrodynamic amperommetry technique at 0.08 V was used for detection of nanomolar concentration of hydrogen peroxide and bromate. Detection limit, sensitivity and linear concentration range proposed sensor for bromate and hydrogen peroxide detection were 1.1 nM and 6.7 nA nM{sup -1}, 10 nM-20 {mu}M, 1 nM, 5.5 nA nM{sup -1} and 10 nM-18 {mu}M, respectively.

  3. Ion chromatography for simultaneous determination of bromate,chlorite and chlorate in drinking water%用离子色谱法同时测定生活饮水中溴酸盐、亚氯酸盐、氯酸盐

    Institute of Scientific and Technical Information of China (English)

    齐春华; 张颖; 王化勇

    2012-01-01

    Objective; To develop an ion chromatography (IC ) for simultaneous determination of chlorite, chlorate and bromate in drinking water. Methods: The IC separation was carried out with the IonPAC AS19 column by using hydroxide eluent at the flow rate of 1.0 ml/min. The injection volume was 500 jxl. Conductivity detection cell temperature was set at 30℃ , column temperature was set at 35℃. Suppressor was in automatic regeneration mode, suppressor current was 87 mA. Results: The results showed that in the range of 0 μg/L to 500 μg/L, the linear e-quation of chlorite was y =2. 640x -0.027, r =0.9999, the detection limit was 0. 1 μg/L; In the range of 0 μg/L ~ 100 μg/L, the linear equation of bromate was y = 1. 342x - 0. 003 , r - 0. 9999 , detection limit was 0. 5 μg/L; In the range of 0 μg/L -500 μg/L, the linear equation of chlorate was y =2. 157x -0. 043 , r -0. 9999, the detection limit was 0.2 μg/L. The recovery rates were 99. 70% ~102.6% and the relative standard deviations (RSD) were 1. 16% ~3.56%. Conclusion; The method is simple,fast,accurate, sensitive, little interference and applicable to the simultaneous determination of chlorite, chlorate and bromate in drinking water.%目的:建立能够同时测定生活饮用水中亚氯酸盐、氯酸盐和溴酸盐的离子色谱法.方法:选择Ion-PacAS19色谱柱,淋洗液为氢氧根淋洗液,流速为1.0 ml/min,进样量为500μl,电导检测池温度为30℃,色谱柱温度为35℃,抑制器抑制模式为自动再生模式,抑制器电流为87 mA.结果:在0μg/L ~ 500.0 μg/L范围内,亚氯酸盐的线性方程为:y=2.640x-0.027,r=0.9999,检出限为0.1 μg/L;在0μg/L ~ 100.0 μg/L溴酸盐的线性方程为:y=1.342x-0.003,r=0.9999,检出限为0.5 μg/L;在0μg/L~500.0 μg/L氯酸盐的线性方程为:y=2.157x-0.043,r=0.9999,检出限为0.2μg/L.加标回收试验结果显示,该方法的平均回收率为99.7% ~102.6%,RSD为1.16% ~3.56%.结论:该法操作简单、快速、准

  4. 大体积直接进样离子色谱法测定饮用水中痕量溴酸盐的方法研究%Determination of trace bromate in drinking water by Large volume direct injection ion chromatography method

    Institute of Scientific and Technical Information of China (English)

    杨国栋

    2012-01-01

    Objective:To establish a large volume direct injection ion chromatography method for conductivity detection of bro-mate in drinking water. Methods; Dionex ICS -20Q0 ion chromatography, EGC II KOH eluent generator, Dionex Ionpac AS19 analytical column, DS6 thermal conductivity detector and ASRS300 anion suppressor were involved in this method. The 10 mmol/L~35 mmol/L KOH was used for gradient elution at the flow rate of 1. 00 ml/min, and the injection volume was 500 ul. Results:It was obtained from the experiment that the correlation coefficient was 0.9999, precision was RSD < 2% , average recoveries were between 95.0% ~ 107% and the minimum detection limit was 5 ug/L. Conclusion; The method has the advantages of simple operation, rapidness, high sensitivity, good reproducibility, which can be used for the analysis of trace bro-roate in drinking water.%目的:建立一种大体积直接进样,电导检测饮用水中痕量溴酸盐的离子色谱分析法.方法:采用Dionex ICS -2000型离子色谱仪,EGCⅡKOH淋洗液自动发生器,10 mmol/L~ 35 mmol/L KOH梯度淋洗,流速1.00 ml/min,Dionex Ionpac AS19型分析柱,DS6型热电导检测器,ASRS300阴离子抑制器,进样体积500μl等分析条件.结果:经实验得到相关系数r =0.9999,精密度RSD <2%,平均加标回收率在95.0%~107%之间,方法的最低检出限为5μg/L.结论:该方法具有操作简单、快速、灵敏度高、重现性好等优点,可应用于饮用水中痕量溴酸盐的分析测定.

  5. Simultaneous analysis of iodate,iodide,bromate and bromide by ion chromatography with ultraviolet detection%离子色谱-紫外检测法同时分析碘酸根、碘离子、溴酸根和溴离子

    Institute of Scientific and Technical Information of China (English)

    李朦; 于泓; 郑秀荣

    2014-01-01

    An analytical method of ion chromatography with ultraviolet detection has been developed and applied for the simultaneous determination of iodate,iodide,bromate and bro-mide. The separation was performed on a quaternary ammonium type anion exchange column with citric acid and acetonitrile as mobile phase. The effects of the detection wavelength,the kind and concentration of the mobile phase and other parameters on separation and detection of the four ions were investigated. The retention rules were studied and the chromatographic con-ditions were optimized. Under the conditions of 210 nm as detection wavelength,0. 9 mL / min as flow rate,40 ℃ as column temperature,and 1. 0 mmol / L citric acid-acetonitrile(85 :15,v /v;pH 5. 0)as mobile phase,the four ions were completely separated and the system peaks and other common anions didn’t interfere with the determination. The detection limits of the four ions(S / N = 3)were 0. 07 - 0. 16 mg / L. The relative standard deviations of the retention times and peak areas obtained by determining samples five times continuously were below 1% . The spiked recoveries of the four anions were from 98. 0% to 102% . This method has been success-fully used to determine ionic liquids synthesized by chemistry laboratory and underground water samples. The results were accurate and reliable.%建立了同时分析碘酸根、碘离子、溴酸根和溴离子的离子色谱-紫外检测分析方法。用季铵型阴离子交换柱,以柠檬酸-乙腈为流动相,采用紫外检测器实现了4种离子的同时分离和检测。研究了检测波长和流动相种类、浓度、pH 值等因素对4种离子分离和测定的影响,探讨了保留规律,优化了色谱分析条件。在检测波长为210 nm、流动相为1.0 mmol / L 柠檬酸-乙腈(85:15,v / v;pH 5.0)、流速为0.9 mL / min、柱温为40℃条件下,4种离子完全分离,且系统峰不干扰测定。4种离子的检出限(S / N =3)为0

  6. Substitute of potassium bromate%溴酸钾的替代物

    Institute of Scientific and Technical Information of China (English)

    岑涛

    2006-01-01

    介绍了溴酸钾等化学氧化剂在面包烘焙中的基本作用,以及酶制剂、乳化剂和非溴酸钾化学氧化剂替代溴酸钾的功能和非溴酸钾改良剂在面包焙烤实验中的效果.

  7. Evaluation of pre-treatments for inhibiting bromate formation during ozonation

    DEFF Research Database (Denmark)

    Antoniou, Maria; Andersen, Henrik Rasmus

    2011-01-01

    limit of 10 μg/L. Depression of solution pH to 6.0, reduced BrO3- formation to half, but it was still well above the water limit. Pre-treatment with NH4+ also reduced BrO3- formation by approximately 50%, though it reduced atrazine degradation to 65%. Pre-treatment with Cl2/NH4+ reduced BrO3- formation......This study compared several pre-treatment methods for inhibiting BrO3- formation during ozonation of tap water, from the DTU campus, including H2O2 addition (perozone), pH-depression, NH4+ and Cl2/NH4+ addition. At the same time, the inhibition of atrazine and carbamazepine removal was evaluated...

  8. Sensitive Spectrophotometric Determination of Atenolol in Pharmaceutical Formulations Using Bromate-Bromide Mixture as an Eco-Friendly Brominating Agent

    Directory of Open Access Journals (Sweden)

    Kudige N. Prashanth

    2012-01-01

    Full Text Available Three simple and sensitive spectrophotometric methods are proposed for the determination of atenolol (ATN in bulk drug and tablets. The methods are based on the bromination of ATN by the bromine generated in situ by the action of the acid on the bromate–bromide mixture followed by the determination of unreacted bromine by reacting with a fixed amount of either meta-cresol purple (MCP and measuring the absorbance at 540 nm (method A and 445 nm (method B or erioglaucine (EGC and measuring the absorbance at 630 nm (method C. Beer's law is valid within the concentration ranges of 1.0–20.0, 2.0–40.0 and 1.0–8.0 μg/mL for method A, method B and method C, respectively. The calculated molar absorptivities were found to be 1.20×104, 4.51×103 and 3.46×104  L/mol⋅cm for method A, method B and method C, respectively. Sandell’s sensitivity values, correlation coefficients, limits of detection and quantification are also reported. Recovery results were statistically compared with those of a reference method by applying Student’s t- and F-test. The novelty of the present study is the measurement of two different colors using MCP, that is, red-pink color of MCP in acid medium at 540 nm and yellowish-orange color of brominated MCP at 445 nm.

  9. 焙烧条件对Ru/AC催化剂去除溴酸盐的影响%Effect of Calcination Conditions on the Activity of Activated Carbon Supported with Ruthenium Catalyst for Bromate Reduction

    Institute of Scientific and Technical Information of China (English)

    朱佳; 董紫君; 陶益; 董文艺

    2014-01-01

    考察了以RuCl3·3H2O为前驱物,以AC(颗粒活性炭)为载体制备Ru/AC时,焙烧氛围、焙烧温度、焙烧时间对Ru/AC催化活性的影响,并利用XPS(X-ray photoelectron spectra,X射线光电子能谱分析)、BET(brunner-emmet-teller method,比表面积测定)和SEM(scanning electronic microscopy,扫描电镜)等手段对样品进行了表征.结果表明,不同焙烧氛围中制备的Ru/AC活性有较大差异:在N2焙烧氛围中,容易形成去除BrO3-的有效活性组分(RuO2);而在真空焙烧氛围中,几乎没有活性组分的产生;在H2-N2[φ(H2)为1.5%,φ(N2)为98.5%]氛围中焙烧,负载在AC上的活性组分有Ru0(单质钌)和RuO2.焙烧温度对Ru/AC去除BrO3的性能有着较为显著的影响,高温有利于AC的石墨化进程,载体性能得到优化;但焙烧温度过高(1 000℃)时,会产生金属颗粒团聚现象;最适宜的焙烧温度为900℃.Ru/AC的活性随着焙烧时间的延长呈先增后降的趋势;焙烧时间为3h时,载体的比表面积和孔容积得到提高且有效活性组分能够均匀地分散在AC载体上.综上,Ru/AC催化剂的最优焙烧条件:焙烧氛围为N2,焙烧温度为900℃,焙烧时间为3h.在该条件下制备的Ru/AC利于形成去除BrO3-的活性物质RuO2,并且其能够均匀地分布在AC载体上,使催化反应进行得更为彻底,可在2h内将BrO3-全部去除.

  10. Determination of trace silver by solid substrate-room temperature phosphorescence quenching method based on double catalytic system of meta-nitrophenyfluorone-polyoxyethylene-chromium-potassium bromate-β-cyclodextrin

    Science.gov (United States)

    Jiaming, Liu; Xuan, Lin; Aihong, Wu; Li-Xiang, Hu; Hangxia, HE; Honghua, Huang; Longdi, Li; Shaoqin, Lin

    2006-09-01

    A new solid substrate-room temperature phosphorescence (SS-RTP) quenching method for the determination of trace silver has been established. It is based on the fact that when using Mg 2+ as ion perturber and β-CD as surfactant, the system of meta-nitrophenyfluorone (R)-polyoxyethylene-Cr(III) can emit strong and stable room temperature phosphorescence signal on filter paper whose surface is modified by polyvinyl alcohol (PVA)-H 3BO 3-NaOH. Ag(I) can catalyze KBrO 3 oxidizing R-PEO-Cr(III) system which causes the quenching of SS-RTP. The reducing value of phosphorescence intensity (Δ Ip) is directly proportional to the concentration of Ag(I) in the range of 3.2-160 ag spot -1 (corresponding concentration: 2.43 fg ml -1, the sample volume: 0.40 μl spot -1) with a detection limit (LD) of 0.97 ag spot -1. The regression equation of working curve can be expressed as Δ Ip = 13.92 + 0.3089 m (ag spot -1) ( r = 0.9983, n = 6). This method has many advantages, such as a wide linear dynamic range, high sensitivity, good repeatability and selectivity. It has been applied to the determination of trace silver in real samples with satisfactory results. What is more, the mechanism of SS-RTP quenching method based on Ag(I) catalyzing KBrO 3 oxidizing meta-nitrophenyfluorone has also been discussed.

  11. Control of Bromate of Drinking Water in Ozone Disinfection Process%饮用水臭氧消毒过程中溴酸盐含量的控制途径

    Institute of Scientific and Technical Information of China (English)

    刘长江; 贾娜; 韩梅

    2014-01-01

    本文论述了给水处理中溴酸根(BrO3-)的控制方法.BrO3-的生成与Br-初始浓度、臭氧投加量、水中天然有机物(NOM)的种类利浓度、有机碳浓度、以及水的pH值等多种因素有关.目前研究较多的削减BrO3-生成势的方法包括降低原水溴离子浓度、改变氯氨工艺、pH值、加氨(NH3)、加羟基自由基抑制剂、加过氧化氢(H2O2)以及多相催化臭氧氧化等多种方法.相比较而言,多相催化臭氧氧化方法克服了向水中投加化学试剂的主要缺点,副作用小,具有较好的发展前景.

  12. Interaction between gaseous ozone and crystalline potassium bromide

    Science.gov (United States)

    Levanov, A. V.; Maksimov, I. B.; Isaikina, O. Ya.; Antipenko, E. E.; Lunin, V. V.

    2016-07-01

    The formation of nonvolatile products of the oxidation of a bromide ion during the interaction between gaseous ozone and powdered crystalline KBr is studied. It is found that potassium bromate KBrO3 is the main product of the reaction. The influence of major experimental factors (the duration of ozonation, the concentration of ozone, the humidity of the initial gas, and the temperature) on the rate of formation of bromate is studied. The effective constants of the formation of bromate during the interaction between O3 and Br- in a heterogeneous gas-solid body system and in a homogeneous aqueous solution are compared.

  13. OZONE CONTACTOR FLOW VISUALIZATION AND CHARACTERIZATION USING 3-DIMENSIONAL LASER INDUCED FLUORESCENCE

    Science.gov (United States)

    Hydrodynamics of ozone contactors have a crucial impact on efficient inactivation of pathogens such as Cryptosporidium as well as control of disinfection byproducts such as bromate. Improper mixing behaviors including short-circuiting, internal recirculation and presence...

  14. Combination of ozonation and photocatalysis for purification of aqueous effluents containing formic acid as probe pollutant and bromide ion.

    Science.gov (United States)

    Parrino, F; Camera-Roda, G; Loddo, V; Palmisano, G; Augugliaro, V

    2014-03-01

    The treatment by advanced oxidation processes (AOPs) of waters contaminated by organic pollutants and containing also innocuous bromide ions may generate bromate ions as a co-product. In the present work heterogeneous photocatalysis and ozonation have individually been applied and in combination (integrated process) to degrade the organic compounds in water containing also bromide anions. The results show that: i) the sole photocatalysis does not produce bromate ions and in the case of its presence, it is able to reduce bromate to innocuous bromide ions; ii) the integration of photocatalysis and ozonation synergistically enhances the oxidation capabilities; and iii) in the integrated process bromate ions are not produced as long as some oxidizable organics are present.

  15. 40 CFR 141.64 - Maximum contaminant levels for disinfection byproducts.

    Science.gov (United States)

    2010-07-01

    ... in this paragraph (a): Disinfection byproduct Best available technology Bromate Control of ozone... source water: Disinfection byproduct Best available technology Total trihalomethanes (TTHM) and... disinfection byproducts. 141.64 Section 141.64 Protection of Environment ENVIRONMENTAL PROTECTION...

  16. The Effect of Ozonation Process on Bromide-Containing Groundwaters in Bandung Area and Its Surroundings

    Directory of Open Access Journals (Sweden)

    Mindriany Syafila

    2012-11-01

    Full Text Available Disinfection process was applied as the last step of the water treatment to kill pathogenic bacteria in the water. However, according to several studies, the ozonation disinfection process could form undesired by-products. One of the by-products potentially affecting human life is bromate produced from bromide ionic-containing water. This study was carried out to examine the effect of raw water characteristics and pH on bromate formation. Also, the performance of bromate formation for a period of exposure time was analyzed. Raw waters taken from four different areas around Bandung were exposed to ozone introduced to a reactor with a flow rate of 2 L/min. The pH of the raw waters varied from 4, 7 to 10. The results show that there was no evidence of an initial bromide ion concentration, whereas a change in pH value gives a significantly different outcome. In acidic condition (pH of 4 the bromate formation tends to decrease, whereas when the pH value increases to a pH of 10, the bromate formation increases. Therefore, for drinking water with a neutral pH, when bromide ions are detected in the raw water, the drinking water may be toxic due to the presence of bromate.

  17. 溴酸钾体系十二烷基苯磺酸钠动力学分光光度法测定食品中痕量铜(Ⅱ)%Determination of Trace Cu (Ⅱ) in Foods by Kinetic Spectrophotometry with Potassium Bromate-Sodium Dodecyl Benzene Sulfonate System

    Institute of Scientific and Technical Information of China (English)

    沈淑君; 李术艳

    2016-01-01

    研究了在表面活性剂十二烷基苯磺酸钠存在下,在pH=9.00的氨性缓冲溶液中,铜(Ⅱ)对溴酸钾氧化中性红褪色有明显的催化作用.通过测定595 nm下吸光度值的变化及其与铜(Ⅱ)浓度的线性关系,建立了分光光度法测定铜(Ⅱ)的新方法.方法的线性范围为0.012~0.12 μg/mL,线性方程为:△A=6.995c-0.0977,相关系数r=0.9992,检出限为7.74×10-10 g/mL.用于食品及水样中痕量铜的测定,结果令人满意,相对标准偏差(RSD,n=6)为1.8%~2.3%.

  18. Catalytic Kinetic Potentiometry for the Determination of Trace Nitrite by the Potassium Bromate-Iodide System%溴酸钾-碘离子体系催化动力学电位法测定痕量亚硝酸根

    Institute of Scientific and Technical Information of China (English)

    刘金霞; 程伟; 孙炳耀

    2002-01-01

    实验中发现NO-2对KBrO3氧化I-的反应有很强的催化作用.可用碘离子选择电极跟踪反应过程,由此建立了测定痕量NO-2的新方法.在适宜条件下,该指示反应为一级反应,反应速度可用电位变化ΔE表示.当时间固定,ΔE与NO-2浓度在0~16×10-6 mol/L范围内呈线性关系,检出限为14×10-10 mol/L.该方法已用于肉类、蔬菜、粮食和血清中NO-2的测定,得到了可靠结果.

  19. 饮用水臭氧消毒副产物——溴酸盐产生机理及影响因素研究进展%Research Advance of Mechanism and Influencing Factors About Ozone Disinfection By-product: Bromate in Drinking Water

    Institute of Scientific and Technical Information of China (English)

    刘利兵; 庞月红; 钱和; 姜雪

    2010-01-01

    随着饮用水安全问题的凸显,饮用水在臭氧消毒过程中产生的消毒副产物溴酸盐也引起了广大消费者的普遍关注.综述了臭氧消毒过程中溴酸盐的产生机理及其对人体健康的影响,并进一步阐述了影响消毒过程中溴酸盐产生的理化因素,为人们正确认识溴酸盐的危害,合理选择饮用水消毒方法和优化消毒工艺提供理论依据.

  20. Kinetic spectrophotometric determination of trace thallium(Ⅲ) based on the discoloring reaction of arsenazo M by oxidation of potassium bromate%溴酸钾氧化偶氮胂M褪色动力学光度法测定痕量铊(Ⅲ)

    Institute of Scientific and Technical Information of China (English)

    周之荣; 张纪文; 周瑜芬; 魏家文

    2006-01-01

    基于0.08 mol/LH2SO4介质中,痕量铊(Ⅲ)催化溴酸钾氧化偶氮胂M(AsAM)的褪色反应,建立了测定痕量铊(Ⅲ)的催化光度法.讨论了酸度、反应物浓度、反应温度、时间、干扰离子等因素的影响.研究了反应的最佳条件,并测定了一些动力学参数,催化反应的表观活化能为70.12kJ/mol.方法检出限为0.17μg/L,线性范围为0~20 μg/L.在25 mL溶液中,测定0.5μg铊(Ⅲ)的相对标准偏差为3.4%(n=11).结合溶剂萃取分离技术,用于测定废水及土壤样品中痕量铊(Ⅲ),回收率为97.0%~103.0%.

  1. Formation of hazardous inorganic by-products during electrolysis of seawater as a disinfection process for desalination.

    Science.gov (United States)

    Oh, Byung Soo; Oh, Sang Guen; Hwang, Youn Young; Yu, Hye-Weon; Kang, Joon-Wun; Kim, In S

    2010-11-01

    From our previous study, an electrochemical process was determined to be a promising tool for disinfection in a seawater desalination system, but an investigation on the production of several hazardous by-products is still required. In this study, a more intensive exploration of the formation patterns of perchlorate and bromate during the electrolysis of seawater was conducted. In addition, the rejection efficiencies of the targeted by-products by membrane processes (microfiltration and seawater reverse osmosis) were investigated to uncover the concentrations remaining in the final product from a membrane-based seawater desalination system for the production of drinking water. On the electrolysis of seawater, perchlorate did not provoke any problem due to the low concentrations formed, but bromate was produced at a much higher level, resulting in critical limitation in the application of the electrochemical process to the desalination of seawater. Even though the formed bromate was rejected via microfiltration and reverse osmosis during the 1st and 2nd passes, the residual concentration was a few orders of magnitude higher than the USEPA regulation. Consequently, it was concluded that the application of the electrochemical process to seawater desalination cannot be recommended without the control of bromate.

  2. Formation of hazardous inorganic by-products during electrolysis of seawater as a disinfection process for desalination.

    Science.gov (United States)

    Oh, Byung Soo; Oh, Sang Guen; Hwang, Youn Young; Yu, Hye-Weon; Kang, Joon-Wun; Kim, In S

    2010-11-01

    From our previous study, an electrochemical process was determined to be a promising tool for disinfection in a seawater desalination system, but an investigation on the production of several hazardous by-products is still required. In this study, a more intensive exploration of the formation patterns of perchlorate and bromate during the electrolysis of seawater was conducted. In addition, the rejection efficiencies of the targeted by-products by membrane processes (microfiltration and seawater reverse osmosis) were investigated to uncover the concentrations remaining in the final product from a membrane-based seawater desalination system for the production of drinking water. On the electrolysis of seawater, perchlorate did not provoke any problem due to the low concentrations formed, but bromate was produced at a much higher level, resulting in critical limitation in the application of the electrochemical process to the desalination of seawater. Even though the formed bromate was rejected via microfiltration and reverse osmosis during the 1st and 2nd passes, the residual concentration was a few orders of magnitude higher than the USEPA regulation. Consequently, it was concluded that the application of the electrochemical process to seawater desalination cannot be recommended without the control of bromate. PMID:20869752

  3. Analytic Solution of the Three-Variable Dynamical Equations of Oscillation Phenomena in B-Z Reaction

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    The dynamical behaviour of the inorganic bromate oscillator catalyzed by manganese ions in the B-Z reaction is discussed, a three-variable nonlinear dynamical equations of the oscillation phenomena have been obtained, and an analytic solution and numerical results of the equations are given.

  4. Characterization of the chlorate reductase from Pseudomonas chloritidismutans

    NARCIS (Netherlands)

    Wolterink, A.F.W.M.; Schiltz, E.; Hagedoorn, P.L.; Hagen, W.R.; Kengen, S.W.M.; Stams, A.J.M.

    2003-01-01

    A chlorate reductase has been purified from the chlorate-reducing strain Pseudomonas chloritidismutans. Comparison with the periplasmic (per)chlorate reductase of strain GR-1 showed that the cytoplasmic chlorate reductase of P. chloritidismutans reduced only chlorate and bromate. Differences were al

  5. DEMONSTRATION OF THE HIPOX ADVANCED OXIDATION TECHNOLOGY FOR THE TREATMENT OF MTBE-CONTAMINATED GROUNDWATER

    Science.gov (United States)

    The HiPOx technology is an advanced oxidation process that incorporates high-precision delivery of ozone and hydrogen peroxide to chemically destroy organic contaminants with the promise of minimizing bromate formation. A MTBE-contaminated groundwater from the Ventura County Nav...

  6. Copper and silver halates

    CERN Document Server

    Woolley, EM; Salomon, M

    2013-01-01

    Copper and Silver Halates is the third in a series of four volumes on inorganic metal halates. This volume presents critical evaluations and compilations for halate solubilities of the Group II metals. The solubility data included in this volume are those for the five compounds, copper chlorate and iodate, and silver chlorate, bromate and iodate.

  7. Ozone and hydrogen peroxide applications for disinfection by-products control in drinking water

    International Nuclear Information System (INIS)

    A great interest has been developed during the last years for ozone in drinking water treatments thanks to its strong oxidant and disinfectant power and for its efficiency in disinfection by-products (DBPs) precursors removal. However ozonization produces some specific DBPs, such as aldehydes and ketones; moreover, the presence of bromide in raw water engages ozone in a complex cycle in which both organic bromide and inorganic bromate are end products. In this paper the combination of hydrogen peroxide with ozone (known as peroxone process) and the ozone alone process were experimented on one surface water coming from the lake of Brugneto (Genova) in order to investigate bromate formation and trihalomethanes precursors removal during the oxidation process. The results show that the advanced peroxone process can be applied for bromate reduction (about 30-40%) with better results in comparison with the ozone alone process, while no advantages are shown for THMs precursors removal. The addition of in-line filtration step after pre-oxidation improves both bromate and THMs precursors removal, particularly with increasing hydrogen peroxide/ozone ratio in the oxidation step

  8. 9 CFR 113.408 - Avian mycoplasma antigen.

    Science.gov (United States)

    2010-01-01

    ... requirements. A 2.5 ml sample of completed antigen shall be diluted with 2.5 ml of buffer solution formulated... with 9 CFR 114.8. If phenol is used, a direct titration with a standardized bromide-bromate solution... tested against the antigens diluted 1:4 in buffer solution formulated in the same manner as the...

  9. Efficient oxidative deprotection of trimethylsilyl, tetrahydropyranyl and methoxymethyl ethers under solvent-free conditions

    Institute of Scientific and Technical Information of China (English)

    Farhad Shirini; Saeideh Saeidi

    2008-01-01

    A mild, efficient and fast method for direct oxidation of trimethylsilyl, tetrahydropyranyl and methoxymethyl ethers to their corresponding carbonyl compounds using trinitratocerium (IV) bromate (TNCB) supported on NaHSO4·H2O under solvent-flee conditions is reported.

  10. 臭氧消毒水中溴酸盐生成及其控制

    Institute of Scientific and Technical Information of China (English)

    王文生; 陈存坤; 于晋泽; 纪海鹏; 贾凝

    2014-01-01

    Based on introducing the application of the technology of ozone disinfection on water treatment and food disinfection, the formation and influencing factors of bromate during the process of ozone disinfection are reviewed. The main factors influencing the formation of bromate are summarized,including the content of bromate in drinking water,ozone dosage and dosing mode,the temperature and pH value of water,ionic strength and the adding additive. The main ways that controls the formation of bromate are concluded.%在介绍臭氧消毒技术在饮用水处理及食品消毒中应用的基础上,对臭氧在水处理消毒杀菌过程中溴酸盐生成及影响因素进行综述;阐明影响溴酸盐生成的主要因素,包括原水中溴化物含量、臭氧投加量和投加方式、臭氧处理时水温及pH值、水中离子强度和投加催化剂等;总结控制溴酸盐生成的主要途径。

  11. Period-doubling and chaotic oscillations in the ferroin-catalyzed Belousov-Zhabotinsky reaction in a CSTR

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    The ferroin-catalyzed Belousov-Zhabotinsky(BZ) reaction,the oxidation of malonic acid by acidic bromate,is the most commonly investigated chemical system for understanding spatial pattern forma-tion. Various oscillatory behaviors were found from such as mixed-mode and simple period-doubling oscillations and chaos on both Pt electrode and Br-ISE at high flow rates to mixed-mode oscillations on Br-ISE only at low flow rates. The complex dynamic behaviors were qualitatively reproduced with a two-cycle coupling model proposed initially by Gy?rgyi and Field. This investigation offered a proper medium for studying pattern formation under complex temporal dynamics. In addition,it also shows that complex oscillations and chaos in the BZ reaction can be extended to other bromate-driven nonlinear reaction systems with different metal catalysts.

  12. Period-doubling and chaotic oscillations the ferroin-catalyzed Belousov-Zhabotinsky reaction in a CSTR

    Institute of Scientific and Technical Information of China (English)

    ZONG ChunYan; GAO QingYu; WANG YuMei; FENG JiaMin; MAO ShanCheng; ZHANG Lu

    2007-01-01

    The ferroin-catalyzed Belousov-Zhabotinsky (BZ) reaction, the oxidation of malonic acid by acidic bromate, is the most commonly investigated chemical system for understanding spatial pattern formation. Various oscillatory behaviors were found from such as mixed-mode and simple period-doubling oscillations and chaos on both Pt electrode and Br-ISE at high flow rates to mixed-mode oscillations on Br-ISE only at Iow flow rates. The complex dynamic behaviors were qualitatively reproduced with a two-cycle coupling model proposed initially by Gy(o)rgyi and Field. This investigation offered a proper medium for studying pattern formation under complex temporal dynamics. In addition, it also shows that complex oscillations and chaos in the BZ reaction can be extended to other bromate-driven nonlinear reaction systems with different metal catalysts.

  13. Belousov-Zhabotinsky oscillatory reaction. Kinetics of malonic acid decomposition

    Directory of Open Access Journals (Sweden)

    LJILJANA KOLAR-ANIC

    2000-10-01

    Full Text Available The kinetics of the Belousov-Zhabotinsky (BZ oscillatory reaction was analyzed. With this aim, the time evolution of a reaction mixture composed of malonic acid, bromate, sulfuric acid and cerium(III was studied at 298 K. Pseudo-first order kinetics with respect to malonic acid as the species undergoing decomposition with a corresponding rate constant, k = 7.5×10-3 min-1, was found.

  14. New considerations on hydrogen peroxide and related substances as food additives in view of carcinogenicity.

    Science.gov (United States)

    Ito, R

    1982-01-01

    The use of hydrogen peroxide as a labile and safe food preservative in fish cake and boiled noodles has recently been restricted by the Japanese government, since hyperplasia has been found in the duodenum of mice after long-term peroral study. The action of compounds with resembling mode of action, potassium bromate as an improving agent in bread, and sodium chlorate as a weed killer are discussed in this paper in view of developmental and environmental pharmacology. PMID:7078983

  15. O-Anisidine as Indicator in Titrimetric Determination of Ascorbic Acid and Isonicotinic Acid Hydrazide in Pharmaceutical Formulations

    OpenAIRE

    Andrews, B. S. A.; B.Sreenivas Rao; Som Shankar Dubey; B.Venkata Kiran

    2010-01-01

    Inspite of the beautiful red coloured oxidized product of O-anisidine, the studies on its application in analytical techniques are scanty. So, authors have taken up the investigation on the utility of O-anisidine as a new Analytical reagent in the bromatometric-Indicator reaction. The detailed reaction on the potassium bromate and OAnisidine has enabled the authors to utilize O-Anisidine in titration of Ascorbic Acid and Isonicitonic Acid Hydrazide. Suitable conditions has been established wi...

  16. Monobromination of Activated Aromatic Compounds withPolyvinylbenzyltriphenylphosphonium Supported Tribromide

    Institute of Scientific and Technical Information of China (English)

    WU Ming-Hu; YANG Gui-Chun; CHEN Zu-Xing

    2001-01-01

    Chloromethylated crosslinked co-polyvinylbenzene-divinylber-zene (2% DVB) was treated with triphenylphospbhie and then with sodium bromate and hydrobromic acid to afford red col-ored insoluble polyvinylbenzyltriphenylphosphon supportedtribromide.This reagent could be used as a mild and efficient monobrominating reagent for activated aromatic compounds such as phenols,aromatic,aromatic amines and acety-lanilines with good yields and high para-selectivity.

  17. Utilization of a Green Brominating Agent for the Spectrophotometric Determination of Pipazethate HCl in Pure Form and Pharmaceutical Preparations

    OpenAIRE

    Ayman A. Gouda

    2013-01-01

    Five simple, accurate, and sensitive spectrophotometric methods (A–E) have been described for the indirect assay of pipazethate HCl (PZT) either in pure form or in pharmaceutical preparations. The proposed methods are based on the bromination of pipazethate HCl with a solution of excess bromate-bromide mixture in hydrochloric acid medium and subsequent estimation of the residual bromine by different reaction schemes. In the first three methods (A–C), the determination of the residual bromine ...

  18. Modélisation du procédé d'ozonation lors de la potabilisation des eaux - Application au contrôle des sous-produits de désinfection: du laboratoire à l'unité industrielle

    OpenAIRE

    Mandel, Pierre

    2010-01-01

    Facing major challenges, management of ozonation process will increasingly need prediction tools based on modelling. Dealing with different types of waters (chemistry) and different types of tanks (hydraulics), modelling of ozonation units has to adapt to site-specific conditions. The main objective of this work was to develop an integrated modelling procedure for industrial ozonation processes for predicting concentration profiles of: ozone, bromate and specific micropollutants. Two types of...

  19. A Novel Chemical Oscillator with Tyrosine as the Substrate

    Institute of Scientific and Technical Information of China (English)

    Wu YANG; Jie REN; Jin Zhang GAO; Hua YANG; Dong Yu Lü; Xiu Hui LIU

    2003-01-01

    A new chemical oscillating reaction system involving the manganese(II)-catalyzed reaction among potassium bromate, acetone and tyrosine in acidic medium was described in this paper. The apparent activation energy of the induction period (Ein) and that of oscillation period (Ep) were calculated, Ein=110.61KJ/mol, Ep=159.41KJ/mol. The optimum concentration of each reactant was investigated and a steady chemical oscillating system was obtained.

  20. An Investigation on Physical and Chemical Quality of Spring Waters

    Directory of Open Access Journals (Sweden)

    Fesem BAŞARI

    2010-12-01

    Full Text Available Objective: The aim of this study was to analyse the chemical and physical qualities of spring water coming to Water Chemistry Laboratory of Adana Hygiene Institute in 2009. The water quality parameters analysed were colour, flavor, odour, turbidity, conductivity, pH, iron, aluminum, boron, manganese, arsenic, ammonia, ozone and bromate. Method: The spring water samples coming to the laboratory, colour in 59 samples, flavor in 22 samples, odour in 57 samples, turbidity and bromate in 61 samples, pH in 63 samples, conductivity in 62 samples, aluminum and iron in 30 samples, boron in 15 samples, arsenic and manganese in 18 samples, ammonia in 60 samples, ozone in 48 samples were studied. ISO (International Organization for Standardization, DIN (Deutsches Institut für Normung, TS (Turkish Standard methods were used for study. The results evaluated according to criterion of ‘‘Regulation on the Quality of Water Intended for Human Comsumption’’.Results: As a result of physical analysis of spring water, turbidity was assigned in just two (%3,2 of 61 samples. pH and conductivity were studied in 63 and in 62 samples respectively and all the values were appropriate. Higher concentrations than the regulation limits were found for bromate in three samples (4,9 % of 61, and in one sample of respectively boron (6,7 % out of 15, manganese (5,6 % out of 18 and arsenic (5,6% out of 18. Aluminum, ammonia, iron and ozone values in the analized samples were not found over the limits.Conclusion: Being found of bromate rates high was related to ozonize. And found of boron, manganese and arsenic was a symptom of dangerous pollution in terms of health. So, spring water pollution control essential for public health.

  1. AOPs with ozone and UV radiation in drinking water: contaminants removal and effects on disinfection byproducts formation.

    Science.gov (United States)

    Collivignarelli, C; Sorlini, S

    2004-01-01

    In this study, the advanced oxidation with ozone and UV radiation (with two low pressure UV lamps, at 254 and 185 nm wavelength) were experimented on a surface water in order to study the removal of two odorous compounds (geosmin and 2-methylisoborneol) and a pesticide (metolachlor), the influence on organic compounds (UV absorbance and THM precursors) and bromate formation. Different batch tests were performed with ozone concentration up to 10 mg/L, UV dose up to 14,000 J/m2 and a maximum contact time of 10 minutes. The main results show that metolachlor can be efficiently removed with ozone alone while for geosmin and MIB a complete removal can be obtained with the advanced oxidation of ozone (with concentration of 1.5-3 mg/L and contact time of 2-3 minutes) with UV radiation (with doses of 5,000-6,000 J/m2). As concerns the influence on the organic precursors, all the experimented processes show a medium removal of about 20-40% for UV absorbance and 15-30% for THMFP (trihalomethanes formation potential). As concerns bromate formation, the advanced oxidation of ozone/UV 254 nm shows a bromate formation that is about 40% lower with respect to conventional oxidation with ozone.

  2. The Effect of Different Boiling and Filtering Devices on the Concentration of Disinfection By-Products in Tap Water

    Directory of Open Access Journals (Sweden)

    Glòria Carrasco-Turigas

    2013-01-01

    Full Text Available Disinfection by-products (DBPs are ubiquitous contaminants in tap drinking water with the potential to produce adverse health effects. Filtering and boiling tap water can lead to changes in the DBP concentrations and modify the exposure through ingestion. Changes in the concentration of 4 individual trihalomethanes (THM4 (chloroform (TCM, bromodichloromethane (BDCM, dibromochloromethane (DBCM, and bromoform (TBM, MX, and bromate were tested when boiling and filtering high bromine-containing tap water from Barcelona. For filtering, we used a pitcher-type filter and a household reverse osmosis filter; for boiling, an electric kettle, a saucepan, and a microwave were used. Samples were taken before and after each treatment to determine the change in the DBP concentration. pH, conductivity, and free/total chlorine were also measured. A large decrease of THM4 (from 48% to 97% and MX concentrations was observed for all experiments. Bromine-containing trihalomethanes were mostly eliminated when filtering while chloroform when boiling. There was a large decrease in the concentration of bromate with reverse osmosis, but there was a little effect in the other experiments. These findings suggest that the exposure to THM4 and MX through ingestion is reduced when using these household appliances, while the decrease of bromate is device dependent. This needs to be considered in the exposure assessment of the epidemiological studies.

  3. ERK Oscillation-Dependent Gene Expression Patterns and Deregulation by Stress-Response

    Energy Technology Data Exchange (ETDEWEB)

    Waters, Katrina M.; Cummings, Brian S.; Shankaran, Harish; Scholpa, Natalie E.; Weber, Thomas J.

    2014-09-15

    Studies were undertaken to determine whether ERK oscillations regulate a unique subset of genes in human keratinocytes and subsequently, whether the p38 stress response inhibits ERK oscillations. A DNA microarray identified many genes that were unique to ERK oscillations, and network reconstruction predicted an important role for the mediator complex subunit 1 (MED1) node in mediating ERK oscillation-dependent gene expression. Increased ERK-dependent phosphorylation of MED1 was observed in oscillating cells compared to non-oscillating counterparts as validation. Treatment of keratinocytes with a p38 inhibitor (SB203580) increased ERK oscillation amplitudes and MED1 and phospho-MED1 protein levels. Bromate is a probable human carcinogen that activates p38. Bromate inhibited ERK oscillations in human keratinocytes and JB6 cells and induced an increase in phospho-p38 and decrease in phospho-MED1 protein levels. Treatment of normal rat kidney cells and primary salivary gland epithelial cells with bromate decreased phospho-MED1 levels in a reversible fashion upon treatment with p38 inhibitors (SB202190; SB203580). Our results indicate that oscillatory behavior in the ERK pathway alters homeostatic gene regulation patterns and that the cellular response to perturbation may manifest differently in oscillating vs non-oscillating cells.

  4. Implications of sequential use of UV and ozone for drinking water quality.

    Science.gov (United States)

    Meunier, Laurence; Canonica, Silvio; von Gunten, Urs

    2006-05-01

    The formation of bromate levels exceeding the drinking water standard of 10 microg L-1 may impose the reduction of ozone doses used in the treatment of drinking water. This paper illustrates the procedure of evaluating the use of reduced ozone doses while implementing an additional UV disinfection step for an actual drinking water treatment plant. Ozonation was performed at low ozone doses in bench-scale experiments with a pretreated river water from the Paris area (France). At the low ozone dose of 0.5 mg L-1, bromate formation could be kept below 0.4 microg L-1, while inactivation of vegetative bacteria and UV-resistant viruses was calculated to exceed 5 log units, and a substantial decoloration (31% of the absorption at lambda=254 nm) was achieved. Based on the measured transient ozone and OH radical concentrations, the oxidation of micropollutants was calculated. Fast reacting micropollutants containing phenol, amine or double bond moieties, such as sulfamethoxazole, diclofenac and 17-alpha-ethinylestradiol, were completely oxidized. Slow-reacting synthetic micropollutants, e.g., atrazine, iopromide and methyl tertiary butyl ether (MTBE), were oxidized by only 20%, 20% and 10%, respectively, and the taste and odor compounds 2-methylisoborneol (MIB) and geosmin by 40% and 50%, respectively. The addition of an UV treatment step to the existing treatment train, which should guarantee disinfection of ozone-resistant pathogenic microorganisms, including Cryptosporidium parvum oocysts, has negligible effects on water matrix components but may induce significant transformation of micropollutants. Overall, the combination of ozonation at reduced doses and UV treatment leads to an improved water quality with regard to disinfection, oxidation of micropollutants and minimization of bromate.

  5. Speciation of the bio-available iodine and bromine forms in edible seaweed by high performance liquid chromatography hyphenated with inductively coupled plasma-mass spectrometry

    International Nuclear Information System (INIS)

    Highlights: ► Bioavailable iodine and bromine speciation in edible seaweed were developed. ► In vitro dialyzability was used to assess the bioavailable fractions. ► AEC hyphenated with inductively coupled plasma-mass spectrometry was used. ► Iodide, MIT, DIT, bromide and bromate were found in dialyzates from edible seaweed. ► Positive correlation between bioavailability and protein contents was found. - Abstract: A bioavailability study based on an in vitro dialyzability approach has been applied to assess the bio-available fractions of iodine and bromine species from edible seaweed. Iodide, iodate, 3-iodo-tyrosine (MIT), 3,5-diiodo-tyrosine (DIT), bromide and bromate were separated by anion exchange chromatography under a gradient elution mode (175 mM ammonium nitrate plus 15% (v/v) methanol, pH 3.8, as a mobile phase, and flow rates within the 0.5–1.5 mL min−1 range). Inductively coupled plasma-mass spectrometry (ICP-MS) was used as a selective detector for iodine (127I) and bromine (79Br). Low dialyzability ratios (within the 2.0–18% range) were found for iodine species; whereas, moderate dialyzability percentages (from 9.0 to 40%) were obtained for bromine species. Iodide and bromide were the major species found in the dialyzates from seaweed, although MIT and bromate were also found in the dialyzates from most of the seaweed samples analysed. However, DIT was only found in dialyzates from Wakame, Kombu, and NIES 09 (Sargasso) certified reference material; whereas, iodate was not found in any dialyzate. Iodine dialyzability was found to be dependent on the protein content (negative correlation), and on the carbohydrate and dietary fibre levels (positive correlation). However, bromine dialyzability was only dependent on the protein amount in seaweed (negative correlation).

  6. Oscillatory behaviour of isomers of hydroxybenzoic acid with and without catalyst

    Energy Technology Data Exchange (ETDEWEB)

    Nath, Masood A.; Rastogi, R.P.; Peerzada, G.M. [University of Kashmir, Srinagar (India). Dept. of Chemistry]. E-mail: nath_masood@yahoo.co.in

    2009-07-01

    The present work establishes and compares the oscillatory behaviour of mono-, di- and trihydroxybenzoic acids as organic substrates in acidic bromate (1.0 mol L{sup -1} H{sub 2}SO{sub 4}) without catalyst and in the presence of Mn{sup 2+} ion as the main catalyst. The oscillations are also affected by other catalyst such as Fe{sup 2+} ion. Further, the oscillations start diminishing in mixed catalyst systems. The experimental parameters were obtained potentiometrically and the results have been interpreted on the basis of FKN mechanism. (author)

  7. Association between age and repair of oxidatively damaged DNA in human peripheral blood mononuclear cells

    DEFF Research Database (Denmark)

    Løhr, Mille; Jensen, Annie; Eriksen, Louise;

    2015-01-01

    damaged DNA in peripheral blood mononuclear cells (PBMCs). We isolated PBMCs from subjects aged 18-83 years, as part of a health survey of the Danish population that focussed on lifestyle factors. The level of DNA repair activity was measured as incisions on potassium bromate-damaged DNA by the comet...... assay. There was an inverse association between age and DNA repair activity with a 0.65% decline in activity per year from age 18 to 83 (95% confidence interval: 0.16-1.14% per year). Univariate regression analysis also indicated inverse associations between DNA repair activity and waist-hip ratio (P...

  8. Ozone and hydrogen peroxide applications for disinfection by-products control in drinking water; Applicazioni con ozono e perossido di idrogeno per il controllo dei sottoprodotti di disinfezione nelle acque potabili

    Energy Technology Data Exchange (ETDEWEB)

    Collivignarelli, C.; Sorlini, S. [Brescia Univ., Brescia (Italy). Dipt. di Ingegneria Civile; Colombino, M. [Azienda Mediterranea Gas e Acqua, Genoa (Italy); Riganti, V. [Pavia Univ., Pavia (Italy). Dipt. di Chimica Generale

    2001-04-01

    A great interest has been developed during the last years for ozone in drinking water treatments thanks to its strong oxidant and disinfectant power and for its efficiency in disinfection by-products (DBPs) precursors removal. However ozonization produces some specific DBPs, such as aldehydes and ketones; moreover, the presence of bromide in raw water engages ozone in a complex cycle in which both organic bromide and inorganic bromate are end products. In this paper the combination of hydrogen peroxide with ozone (known as peroxone process) and the ozone alone process were experimented on one surface water coming from the lake of Brugneto (Genova) in order to investigate bromate formation and trihalomethanes precursors removal during the oxidation process. The results show that the advanced peroxone process can be applied for bromate reduction (about 30-40%) with better results in comparison with the ozone alone process, while no advantages are shown for THMs precursors removal. The addition of in-line filtration step after pre-oxidation improves both bromate and THMs precursors removal, particularly with increasing hydrogen peroxide/ozone ratio in the oxidation step. [Italian] Un notevole interesse e' stato mostrato di recente per l'utilizzo dell'ozono nei trattamenti di potabilizzazione sia per il suo forte potere ossidante e disinfettante sia per la capacita' di rimuovere alcuni precursori di formazione dei sottoprodotti di ossidazione (OBPs). Tuttavia, anche l'ozono puo' produrre a sua volta alcuni specifici sottoprodotti, quali aldeidi e chetoni; inoltre, la presenza di bromuro nell'acqua grezza coinvolge l'ozono in una serie di reazioni che portano alla formazione di composti organici bromurati e di sottoprodotti inorganici, i piu' noti tra i quali sono i bromati. In questo articolo vengono presentati i risultati di alcuni trattamenti di ossidazione convenzionali a base di ozono combinato con perossido di idrogeno

  9. The role of Ce(III) in BZ oscillating reactions

    Science.gov (United States)

    Nogueira, Paulo A.; Varela, Hamilton; Faria, Roberto B.

    2012-03-01

    Herein we present results on the oscillatory dynamics in the bromate-oxalic acid-acetone-Ce(III)/Ce(IV) system in batch and also in a CSTR. We show that Ce(III) is the necessary reactant to allow the emergence of oscillations. In batch, oscillations occur with Ce(III) and also with Ce(IV), but no induction period is observed with Ce(III). In a CSTR, no oscillations were found using a freshly prepared Ce(IV), but only when the cerium-containing solution was aged, allowing partial conversion of Ce(IV) to Ce(III) by reaction with acetone.

  10. A Pendulum-Like Motion of Nanofiber Gel Actuator Synchronized with External Periodic pH Oscillation

    Directory of Open Access Journals (Sweden)

    Shuji Hasimoto

    2011-02-01

    Full Text Available In this study, we succeeded in manufacturing a novel nanofiber hydrogel actuator that caused a bending and stretching motion synchronized with external pH oscillation, based on a bromate/sulfite/ferrocyanide reaction. The novel nanofiber gel actuator was composed of electrospun nanofibers synthesized by copolymerizing acrylic acid and hydrophobic butyl methacrylate as a solubility control site. By changing the electrospinning flow rate, the nanofiber gel actuator introduced an anisotropic internal structure into the gel. Therefore, the unsymmetrical motion of the nanofiber actuator was generated.

  11. Ultra-trace analysis of nitrite in food samples by flow injection with spectrophotometric detection

    Energy Technology Data Exchange (ETDEWEB)

    Ensafi, A.A.; Bagherian Dehaghei, G. [College of Chemistry, Isfahan University of Technology, Isfahan (Iran, Islamic Republic of)

    1999-01-01

    A flow injection system with spectrophotometric detection is proposed for the determination of low levels of nitrite based on its catalytic effect on the oxidation of gallocyanine by bromate in acidic media. Various analytical parameters such as acidity, reagent concentration, flow rate, sample size, time, temperature, and interfering species were studied. The calibration graph was linear for 0.020-0.500 {mu}g/mL of nitrite. The method is successfully applied to food samples. Up to 30 {+-} 5 samples can be analyzed per hour. (orig.) With 3 figs., 3 tabs., 17 refs.

  12. Evaluation of the sensitivity of three sublethal cytotoxicity assays in human HepG2 cell line using water contaminants

    OpenAIRE

    Jondeau, Adeline; DAHBI, Laurence; Bani-Estivals, Marie-Helene; Chagnon, Marie-Christine

    2006-01-01

    The in vitro toxicological index IC50 (the millimolar concentration of compound which inhibits response assay by 50% compared to the solvent control) of 11 water contaminants (acrylamide, atrazine, B[a]P, BPA, 2,4-DAT, 17-alphaEE, H(2)O(2), 4-OP, sodium bromate, sodium chlorate, sodium nitrate) was evaluated on the human hepatoma (HepG2) cells using three short-term bioassays related to their morbidity status [radiometric RNA synthesis assay (RNA), luminometric ATP assay (ATP), fluorometric A...

  13. ESTERIFICATION OF ACRYLIC ACID WITH 1-BUTANOL IN LIQUID PHASE CATALYZED WITH AL-MCM-41

    OpenAIRE

    Edson Avellaneda Maytán; Gustavo Paim Valença

    2010-01-01

    This work studies the esterification of acrylic acid with 1-butanol using Al-MCM-41 as catalyst with different degrees of acidity at different temperatures. Al-MCM-41 synthesis was made from bromate Cetyl trimethyl ammonium using as router agent, NH4OH (25%), deionized H2O and Al2(SO4)3. Catalytic tests were carried out by groups and worked with temperature ranges among (333 to 348) K and a small sample was collected at predetermined intervals of time for subsequent gas chromatography analysi...

  14. Removal of micro-pollutants from drinking water with advanced oxidation processes

    OpenAIRE

    Sander, Fabian

    2009-01-01

    This thesis determines the feasibility of ozone gas and ultraviolet (UV)technologies to reduce pollutants from drinking water. The merging of both techniques, ozone and UV, is known as a so called advanced oxidation process (AOP). ITT Wedeco is developing new technologies to meet the growing concern of water works to remove micro-pollutants from their water. The emphasis of this work was put on the formation of the oxidation by-product bromate and the removal of the solvent 1.4 dioxane fr...

  15. EFFECTS STUDY OF NIGELLA SATIVA, ITS OIL AND THEIR COMBINATION WITH VITAMIN E ON OXIDATIVE STRESS IN RATS

    OpenAIRE

    Amr A. Rezq

    2014-01-01

    Antioxidants or free radical scavengers are very important in protecting the living cells against any damage induced by free radicals. The effects of Nigella Sativa Extract (NSE), Nigella Sativa Oil (NSO) and Vitamin E (Vit. E) and the combination of NSE or NSO with Vit. E on potassium bromate (KBrO3)-induced oxidative stress in male rats were investigated. Forty nine Sprague Dawley male rats were weighingv 185±5 g and 10-12 weeks old were used to achieve the pre...

  16. Determination of Trace Titanium by Catalytic Kinetic Spectrophtometry

    Institute of Scientific and Technical Information of China (English)

    ZHAI Qing-zhou; ZHANG Hao

    2007-01-01

    The optimum conditions of discoloring reaction of DBM-arsenazo oxidized by potassium bromate and catalyzed by trace titanium ( Ⅳ ) are studied and a new catalytic-kinetic spectrophotometric method for determination of trace titanium is developed. The linear range of determination of titanium ( Ⅳ ) is 0 - 48 ng/mL at 530 nm. The detection limit of the method is 0.084 ng/mL. The method is used for the determination of titanium in water samples and the analytical results are in excellent agreement with those by atomic absorption spectrometry.

  17. Catalytic spectrophotometric determination of trace selenium in microemulsion after separation and enrichment by SDG

    Institute of Scientific and Technical Information of China (English)

    LI Huizhi; ZHAI Diantang; FAN Yingju

    2006-01-01

    A new catalytic spectrophotometric method was developed for the determination of trace amount of Se(Ⅳ) in microemulsion medium. The method is based on the catalytic effect of traces of Se(Ⅳ) on the oxidation of2',4'-dichlorophenylfluorone (p-CPF) by potassium bromate with HNO3 as an activator in the presence of nonionic microemulsion medium. Under optimum conditions, the calibration graph is linear in the range of 0.4-15 μg. L-1 of Se(Ⅳ) atseparated and enriched by sulphydryl dextrane gel (SDG). The method has been applied for determination of trace selenium with satisfactory results.

  18. Renal deterioration caused by carcinogens as a consequence of free radical mediated tissue damage: a review of the protective action of melatonin.

    Science.gov (United States)

    Gultekin, Fatih; Hicyilmaz, Hicran

    2007-10-01

    This brief review summarizes some of the publications that document the preventive role of melatonin in kidney damage caused by carcinogens such as 2-nitropropane, arsenic, carbon tetrachloride, nitrilotriacetic acid and potassium bromate. Numerous chemicals generate excessive free radicals that eventually induce renal worsening. Melatonin partially or totally prevents free radical mediated tissue damages induced by many carcinogens. Protective actions of melatonin against the harmful effects of carcinogens are believed to stem from its direct free radical scavenging and indirect antioxidant activities. Dietary or pharmacologically given melatonin may attenuate the oxidative stress, thereby mitigating the subsequent renal damage. PMID:17823789

  19. Renal deterioration caused by carcinogens as a consequence of free radical mediated tissue damage: a review of the protective action of melatonin

    Energy Technology Data Exchange (ETDEWEB)

    Gultekin, Fatih; Hicyilmaz, Hicran [Suleyman Demirel University, School of Medicine, Department of Biochemistry, Isparta (Turkey)

    2007-10-15

    This brief review summarizes some of the publications that document the preventive role of melatonin in kidney damage caused by carcinogens such as 2-nitropropane, arsenic, carbon tetrachloride, nitrilotriacetic acid and potassium bromate. Numerous chemicals generate excessive free radicals that eventually induce renal worsening. Melatonin partially or totally prevents free radical mediated tissue damages induced by many carcinogens. Protective actions of melatonin against the harmful effects of carcinogens are believed to stem from its direct free radical scavenging and indirect antioxidant activities. Dietary or pharmacologically given melatonin may attenuate the oxidative stress, thereby mitigating the subsequent renal damage. (orig.)

  20. UV-based advanced oxidation processes for the treatment of odour compounds: efficiency and by-product formation.

    Science.gov (United States)

    Zoschke, Kristin; Dietrich, Norman; Börnick, Hilmar; Worch, Eckhard

    2012-10-15

    The occurrence of the taste and odour compounds geosmin and 2-methyl isoborneol (2-MIB) affects the organoleptic quality of raw waters from drinking water reservoirs worldwide. UV-based oxidation processes for the removal of these substances are an alternative to adsorption and biological processes, since they additionally provide disinfection of the raw water. We could show that the concentration of geosmin and 2-MIB could be reduced by VUV irradiation and the combination of UV irradiation with ozone and hydrogen peroxide in pure water and water from a drinking water reservoir. The figure of merit EE/O is an appropriate tool to compare the AOPs and showed that VUV and UV/O(3) yielded the lowest treatment costs for the odour compounds in pure and raw water, respectively. Additionally, VUV irradiation with addition of ozone, generated by the VUV lamp, was evaluated. The generation of ozone and the irradiation were performed in a single reactor system using the same low-pressure mercury lamp, thereby reducing the energy consumption of the treatment process. The formation of the undesired by-products nitrite and bromate was investigated. The combination of VUV irradiation with ozone produced by a VUV lamp avoided the formation of relevant concentrations of the by-products. The internal generation of ozone is capable to produce ozone concentrations sufficient to reduce EE/O below 1 kWh m(-3) and without the risk of the formation of nitrite or bromate above the maximum contaminant level.

  1. Extraction of palm tree cellulose and its functionalization via graft copolymerization.

    Science.gov (United States)

    Al-Hoqbani, Abdulmajeed A; Abdel-Halim, E S; Al-Deyab, Salem S

    2014-09-01

    The work in this paper was planned with the aim of extracting the cellulosic component of palm tree waste and functionalizing this cellulose through graft copolymerization with acrylic acid. The cellulose extraction included hot alkali treatment with aqueous sodium hydroxide to remove the non-cellulosic binding materials. The alkali treatment was followed by an oxidative bleaching using peracid/hydrogen peroxide mixture with the aim of removing the rest of non-cellulosic materials to improve the fiber hydrophilicity and accessibility towards further grafting reaction. Optimum conditions for cellulose extraction are boiling in 5% (W/V) NaOH in a material to liquor ratio of 1:20 for 1 h then bleaching with 60 ml/l bleaching mixture at initial pH value of 6.5 for 30 min. The pH of the bleaching medium is turned to the alkaline range 11 and bleaching continues for extra 30 min. Graft copolymerization reaction was initiated by potassium bromate/thiourea dioxide redox system. Optimum conditions for grafting are 30 mmol of potassium bromate, 30 mmol of thiourea dioxide and 150 g of acrylic acid (each per 100 g of cellulose). The polymerization reaction was carried out for 120 min at 50°C using a material to liquor ratio of 1:20. PMID:25020080

  2. Green synthesis of 5-bromo-vanillin%5-溴香兰素的绿色合成

    Institute of Scientific and Technical Information of China (English)

    彭安顺; 英荣建

    2009-01-01

    以冰醋酸为溶剂,香兰素为原料,AlBr3为催化剂,HBrO3与KBrO3为溴化剂合成了5-溴香兰素.采用正交实验法考察了影响收率的因素.最佳条件为:香兰素、KBrO3与AlBr3的物质的量的摩尔比为1:0.5:0.056,反应时间6.0h,反应温度30℃.在优化条件下收率可达90.4%.产物结构通过IR、1HNMR、熔点测定和元素分析得以确认.%5-bromo-vanillin was synthesizedby using vanillin as raw material,aluminium chloride as catalyst, hydrobromic acid and potassium bromate as brominating agent and acetic acid as solvent.Factors influencing the yield were investigated by the orthogonal experimental method.The optimum conditions are as follows:Vanillin: potassium bromate:aluminium chloride is 1mol:0.5mol:0.056mol, reaction time is 6.0h,reaction temperature is 30%. The yield is above 90.4% under the optimum conditions. The title compound was characterized by IR,1H NMR,mp. Measurement and element analysis.

  3. Synthesis of α-Bromine- Terminated Polystyrene Macroinitiator and Its Initiation of MMA Polymerization by ATRP

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    In the present paper the synthesis of block copolymers via the transformation from living anionic polymerization (LAP) to atom transfer radical polymerization (ATRP) was described. Α-Bromine-terminated polystyrenes(PStBr) in the LAP step was prepared by using n-BuLi as initiator, tetrahydrofuran (THF) as the activator, α-methylstyrene (α-MeSt) as the capping group and liquid bromine (Br2) as the bromating agent. The effects of reaction conditions such as the amounts of α-MeSt, THF, and Br2 as well as molecular weight of polystyrene on the bromating efficiency (BE) and coupling extent (CE) were examined. The present results show that the yield of PStBr obtained was more than 93.8% and the coupling reaction was substantially absent. PStBr was further used as the macroinitiator in the polymerization of methyl-methacrylate(MMA) in the presence of copper(Ⅰ) halogen and 2,2-bipyridine(bpy) complexes. It was found that the molecular weight of the resulted PSt-b-PMMA increased linearly with the increase of the conversion of MMA and the polydispersity was 1.2-1.6. The structures of PStBr and P(St-b-MMA) were characterized by 1H NMR spectra.

  4. Second-order advantage from kinetic-spectroscopic data matrices in the presence of extreme spectral overlapping

    Energy Technology Data Exchange (ETDEWEB)

    Culzoni, Maria J. [Laboratorio de Desarrollo Analitico y Quimiometria (LADAQ), Catedra de Quimica Analitica I, Facultad de Bioquimica y Ciencias Biologicas, Universidad Nacional del Litoral, Ciudad Universitaria, Santa Fe S3000ZAA (Argentina); Goicoechea, Hector C. [Laboratorio de Desarrollo Analitico y Quimiometria (LADAQ), Catedra de Quimica Analitica I, Facultad de Bioquimica y Ciencias Biologicas, Universidad Nacional del Litoral, Ciudad Universitaria, Santa Fe S3000ZAA (Argentina)], E-mail: hgoico@fbcb.unl.edu.ar; Ibanez, Gabriela A.; Lozano, Valeria A. [Departamento de Quimica Analitica, Facultad de Ciencias Bioquimicas y Farmaceuticas, Universidad Nacional de Rosario and Instituto de Quimica Rosario (IQUIR-CONICET), Suipacha 531, Rosario S2002LRK (Argentina); Marsili, Nilda R. [Laboratorio de Desarrollo Analitico y Quimiometria (LADAQ), Catedra de Quimica Analitica I, Facultad de Bioquimica y Ciencias Biologicas, Universidad Nacional del Litoral, Ciudad Universitaria, Santa Fe S3000ZAA (Argentina); Olivieri, Alejandro C. [Departamento de Quimica Analitica, Facultad de Ciencias Bioquimicas y Farmaceuticas, Universidad Nacional de Rosario and Instituto de Quimica Rosario (IQUIR-CONICET), Suipacha 531, Rosario S2002LRK (Argentina)], E-mail: aolivier@fbioyf.unr.edu.ar; Pagani, Ariana P. [Departamento de Quimica Analitica, Facultad de Ciencias Bioquimicas y Farmaceuticas, Universidad Nacional de Rosario and Instituto de Quimica Rosario (IQUIR-CONICET), Suipacha 531, Rosario S2002LRK (Argentina)

    2008-04-28

    Multivariate curve resolution coupled to alternating least-squares (MCR-ALS) has been employed to model kinetic-spectroscopic second-order data, with focus on the achievement of the important second-order advantage, under conditions of extreme spectral overlapping among sample components. A series of simulated examples shows that MCR-ALS can conveniently handle the studied analytical problem unlike other second-order multivariate calibration algorithms, provided matrix augmentation is implemented in the spectral mode instead of in the usual kinetic mode. The approach has also been applied to three experimental examples, which involve the determination of: (1) the antiparkinsonian carbidopa (analyte) in the presence of levodopa as a potential interferent, both reacting with cerium (IV) to produce the fluorescent species cerium (III) with different kinetics; (2) Fe(II) (analyte) in the presence of the interferent Zn(II), both catalyzing the oxidation of methyl orange with potassium bromate; and (3) tartrazine (analyte) in the presence of the interferent brilliant blue, both oxidized with potassium bromate, with the interferent leading to a product with an absorption spectrum very similar to tartrazine. The results indicate good analytical performance towards the analytes, despite the intense spectral overlapping and the presence of unexpected constituents in the test samples.

  5. Kinetic spectrophotometric determination of trace amounts of selenium and vanadium

    Energy Technology Data Exchange (ETDEWEB)

    Safavi, A.; Sedghy, H.R.; Shams, E. [Dept. of Chemistry, Shiraz Univ. (Iran)

    1999-11-01

    A sensitive kinetic spectrophotometric method has been developed for the determination of Se(IV) over the range of 45 to 4000 ng in 10 mL of solution. The method is based on the catalytic effect of Se(IV) on the reduction reaction of bromate by hydrazinium dichloride, with subsequent reaction of Ponceau S with products of the above reaction (chlorine and bromine), causing color changing of Ponceau S. Method development includes optimization of time interval for measurement of slope, pH, reagents concentration, and temperature. The optimized conditions yielded a theoretical detection limit of 33 ng/10 mL of solution of Se(IV). The interfering effects were studied and removed. The method was applied to the determination of selenium in spiked water, Kjeldahl tablet, selenium tablet, and shampoo. Vanadium(V) has an inhibition effect on the catalyzed reaction of bromate and hydrazine by selenium. Using this effect, V(V) can be determined in the range of 70 to 2500 ng in 10 mL of solution. The optimization procedure includes pH and selenium concentration. An extraction method was used for interference removal. The method was applied to the determination of vanadium in petroleum. (orig.)

  6. Preozonation of bromide-bearing source water in south China

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    The effectiveness of preozonation was evaluated on treating a bromide-bearing dam source water in south China through batch-scale experiments. Preozonation at ozone doses of 0.5-1.0 mg/L (at ozone consumption base) enhanced total organic carbon(TOC) removal through coagulation, and resulted in an almost linear reduction of ultraviolet absorbance at 254 nm (UV254). The removals of TOC (after coagulation) and UV254 at the ozone dose of 1.0 mg/L were 36% and 70%, respectively. Preozonation at an ozone dose between 0.5 and 1.0 mg/L resulted in the removal of disinfection byproducts formation potential (DBFP) including trihalomethane formation potential (THMFP) and haloacetic acid formation potential (HAAFP) for about 50%. The removals of THMFP and HAAFP decreased with the further increase of ozone dose. Ozonation of bromide-bearing water (bromide concentration,34 μg/L) produced a bromate concentration under the detection limit(2 μg/L) at ozone doses < 1.5 mg/L. However, bromate >10 μg/L could be produced when the bromide concentration was increased to 96 μg/L.

  7. Acute and chronic toxicity of selected disinfection byproducts to Daphnia magna, Cyprinodon variegatus, and Isochrysis galbana.

    Science.gov (United States)

    Fisher, Daniel; Yonkos, Lance; Ziegler, Gregory; Friedel, Elizabeth; Burton, Dennis

    2014-05-15

    Ballast water treatment has become a major issue in the last decade due to the problem of invasive species transported and released by the uptake and discharge of ballast water for shipping operations. One of the important issues considering ballast water treatment is to determine whether treated ballast water, once discharged, is safe to the aquatic environment. The International Maritime Organization (IMO) Marine Environmental Protection Committee (MEPC) has determined that prior to approval of a ballast water management system, aquatic toxicity data must be available for both the active substance and relevant byproducts. Many proposed ballast water treatment systems use chlorine as the active ingredient. Although there are sufficient toxicity data concerning active substances such as chlorine, there are limited toxicity data concerning disinfection (halogenated) byproducts including dibromochloromethane, four haloacetic acids and sodium bromate. Acute and chronic toxicity were determined for these disinfection byproducts (DBPs). Acute toxicity values ranged from 96-h LC50s of 46.8 mg/l for Daphnia magna for both dibromochloromethane and sodium bromate to a 96-h LC50 of 376.4 mg/l for Cyprinodon variegatus for tribromoacetic acid. Acute Isochrysis galbana population growth effect values ranged from a 72-h EC10 of 39.9 mg/l for dichloroacetic acid to a 72-h EC50 of 15,954 mg/l for sodium bromate. Chronic toxicity mortality/reproduction effects values for D. magna ranged from a 21-d IC25 of 160.9 mg/l for tribromoacetic acid to a 21-d LOEC of 493.0 mg/l for trichloroacetic acid. Chronic toxicity mortality/growth values for C. variegatus ranged from a 32-d IC25 of 246.8 mg/l for trichloroacetic acid to a 32-d LOEC of 908.1 mg/l for tribromoacetic acid. I. galbana 96-h chronic population growth effects values ranged from an EC10 of 38.5 mg/l for trichloroacetic acid to an LOEC of 500.0 mg/l for tribromoacetic acid. Acute to chronic ratios for all of these

  8. Semiconductor-mediated photocatalysed degradation of two selected azo dye derivatives, amaranth and bismarck brown in aqueous suspension.

    Science.gov (United States)

    Tariq, M Abu; Faisal, M; Muneer, M

    2005-12-01

    Semiconductor-mediated photocatalysed degradation of two selected azo dye derivatives such as amaranth (1) and bismarck brown (2) has been investigated in aqueous suspension by monitoring the change in substrate concentration employing UV spectroscopic analysis technique as a function of irradiation time. The degradation was studied under different conditions such as types of TiO(2), pH, substrate concentration, catalyst concentration, and in the presence of electron acceptors such as hydrogen peroxide (H(2)O(2)), potassium bromate (KBrO(3)) and ammonium persulphate (NH(4))(2)S(2)O(8) besides air. The degradation rates were found to be strongly influenced by all the above parameters. The photocatalyst Degussa P25 showed comparatively highest photocatalytic activity. The dye derivative, bismarck brown (2) was found to degrade faster than amaranth dye (1).

  9. 3-溴-4-羟基-5-甲氧基苯甲酸甲酯的合成%Synthesis of 3-bromo-4-hydroxy-5-methoxy-benzoic Acid Methyl Ester

    Institute of Scientific and Technical Information of China (English)

    闫慧丽; 张立新; 张慧芳; 马甲民

    2011-01-01

    以香兰素为主要原料,经溴水溴代得溴代香兰素,再经氧化银氧化制取溴代香兰酸,最后与甲醇发生酯化反应,成功制得3-溴-4-羟基-5-甲氧基苯甲酸甲酯,总收率66.4%.各步反应的生成物提纯后经过1H-NMR、IR进行表征.%3-bromo4-hydroxy-5-methoxy-benzoic acid methyl ester in total yield of 66.4% is synthesized from vanillin via bromation by bromide, oxidation over silver oxide and esterification with methanol.The products from different steps are identified by 1H-NMR and IR.

  10. A fixed cations and low Tg polymer: the poly(4-vinyl-pyridine) quaternized by poly(ethylene oxide) links. Conductivity study; Un electrolyte polymere a cations fixes et bas Tg: les poly(4-vinylpyridine) quaternisees par des chainons de poly(oxyde d`ethylene). Etude de la conductivite

    Energy Technology Data Exchange (ETDEWEB)

    Gramain, Ph. [Ecole Nationale Superieure de Chimie de Montpellier, 34 (France); Frere, Y. [Centre National de la Recherche Scientifique (CNRS), 67 - Strasbourg (France). Institut Charles Sadron

    1996-12-31

    The spontaneous ionic polymerization of 4-vinyl-pyridine in presence of mono-tosylated or bromated short chains of poly(ethylene oxide)-(PEO) is used to prepare amorphous comb-like poly-cations with low Tg. The polymer electrolyte properties of these new structures have been studied without any addition of salts. The ionic conductivity of these fixed cation poly-electrolytes depends on the length of the grafted PEO and varies from 10{sup -7} to 10{sup -4} S/cm between 25 and 80 deg. C. It is only weakly dependent on the nature of the cation but it is controlled by the movements of the pyridinium cation which are facilitated by the plastifying effect of the POE chains which do not directly participate to the ionic transport. (J.S.) 17 refs.

  11. Photoassisted Degradation of a Herbicide Derivative, Dinoseb, in Aqueous Suspension of Titania

    Directory of Open Access Journals (Sweden)

    Niyaz A. Mir

    2012-01-01

    Full Text Available The titanium dioxide (TiO2 photoassisted degradation of herbicide dinoseb has been examined in aqueous suspensions under UV light irradiation. The degradation kinetics were studied under various conditions such as substrate concentration, type of catalyst, catalyst dosage, pH, and light intensity as well as in presence of electron acceptors such as hydrogen peroxide, potassium bromate, and potassium persulphate under continuous air purging, and the degradation rates were found to be strongly influenced by these parameters. The Degussa P25 was found to be more efficient photocatalyst as compared to other photocatalysts tested. Dinoseb was found to degrade efficiently in acidic pH and all the electron acceptors studied enhanced the degradation rate. The results manifested that the photocatalysis of dinoseb followed pseudo-first-order kinetics. A qualitative study of the degradation products generated during the process was performed by GC-MS, and a degradation mechanism was proposed.

  12. [Investigation of the oxidation reaction of O3 with bromide ion in aqueous solution].

    Science.gov (United States)

    Yu, Xiao-Ting; Zhang, Jia-Hui; Pan, Xun-Xi; Zhang, Ren-Xi; Hou, Hui-Qi

    2012-09-01

    The reaction mechanism of O3 with bromide ion in aqueous solution was studied by ion chromatography and UV-Vis spectrometry instruments. Ion chromatography analysis showed that only 10% of Br- which was oxidized by ozone was formed into bromate ion. The results demonstrated that the final products of the oxidation reaction were identified as Br2 and Br3- except for BrO3-. The formation of Br3- which was yielded from the reaction of Br2 with Br- was the major process in the reaction of Br attacked by O3. The characteristic absorption spectrum of Br3- with an absorption peak at 260 nm was also investigated. The results may provide helpful information about the mechanism of the oxidation reaction of Br- with O3 and fate of Br- or its derivatives in the environment by the oxidation processes.

  13. Catalytic determination of ultra trace amounts of vanadium with detection by linear sweep voltammetry

    Energy Technology Data Exchange (ETDEWEB)

    Ensafi, Ali A. [College of Chemistry, Isfahan University of Technology, Isfahan (Iran, Islamic Republic of); Naderi, B. [College of Chemistry, Isfahan University of Technology, Isfahan (Iran, Islamic Republic of)

    1997-06-01

    Vanadium has a very strong catalytic effect on the bromate oxidation of gallocyanine at pH of 4.0. The oxidation product of gallocyanine exhibit a voltammetric wave at + 0.10 V vs. Ag/AgCl reference electrode in 0.10 mol/l KNO{sub 3} medium. The linear scan voltammetric behaviour of the reaction products at HMDE has been studied and selected as the indicator component for the reaction. A detection limit of 0.05 ng/ml and calibration graph from 0.30-200.00 ng/ml vanadium were obtained. Vanadium in water and gasoline samples was determined by this method, with satisfactory results. (orig.). With 5 figs., 2 tabs.

  14. O-Anisidine as Indicator in Titrimetric Determination of Ascorbic Acid and Isonicotinic Acid Hydrazide in Pharmaceutical Formulations

    Directory of Open Access Journals (Sweden)

    B.S.A.Andrews

    2010-10-01

    Full Text Available Inspite of the beautiful red coloured oxidized product of O-anisidine, the studies on its application in analytical techniques are scanty. So, authors have taken up the investigation on the utility of O-anisidine as a new Analytical reagent in the bromatometric-Indicator reaction. The detailed reaction on the potassium bromate and OAnisidine has enabled the authors to utilize O-Anisidine in titration of Ascorbic Acid and Isonicitonic Acid Hydrazide. Suitable conditions has been established with different acids viz., hydrochloric acid, sulfuric acid, phosphoric acid, acetic acid to give sharp colour change at the equivalence point. The present method has been applied for the estimation of Ascorbic acid and also Isonicitonic Acid Hydrazide in pharmaceutical formulations and results obtained are in good agreement with the values obtained by standard methods

  15. Kinetic Determination of Uric Acid in Human Serum by Using the Uncatalyzed BZ Reaction in Non-equilibrium Steady State

    Institute of Scientific and Technical Information of China (English)

    Ren, Jie; Yang, Wu; Niu, Xiuli; Gao, Jinzhang

    2012-01-01

    A novel kinetic method for determination of uric acid in human serum by means of an uncatalyzed BZ system consisting of potassium bromate and p-hydroxybenzaldehyde (p-HBA) in sulfuric acid medium was proposed, in which the analyte perturbation to the system was recorded close to the bifurcation point. The potential change was directly proportional to the logarithm of concentration of uric acid in the range of 3.73 × 10 8--7.48 × 10-4 mol.L-1 (r=0.9983) with a detection limit of 7.45 × 10-9mol.L-I and a recovery from 98.9% to 101.1%. A comparison between the proposed technique and other methods indicated that results obtained were in agreement with those in clinical detection. In addition, the possible mechanism of action of uric acid on the uncatalyzed BZ reaction was also discussed briefly.

  16. Inorganic-Organic Hybrid 18-Molybdodiphosphate Nanoparticles Bulk-modified Carbon Paste Electrode and Its Electrocatalysis

    Institute of Scientific and Technical Information of China (English)

    WANG,Xiu-Li(王秀丽); KANG,Zhen-Hui(康振辉); WANG,En-Bo(王恩波); HU,Chang-Wen(胡长文)

    2002-01-01

    A kind of inorganic- organic hybrid 18-molybdodiphosphate nanoparticles ([(C4H9)4N]6P2Mo18O62 @4H2O) was firstly used as a bulk-modifier to fabricate a three-dimensional chemically modified carbon paste electrode (CPE) by direct mixing. The electrochemical behavior of the solid nanoparticles dispersed in the CPE in acidic aqueous solution was characterized by cyclic and square-wave voltammetry. The hybrid 18-molybdodiphosphate nanoparticles bulk-modified CPE (MNP-CPE) displayed a high electrocatalytic activity towards the reduction of nitrite,bromate and hydrogen peroxide. The remarkable advantages of the MNP-CPE over the traditional polyoxometalates-modified electrodes are their excellent reproducibility of surface-renewal and high stability owing to the insolubility of the hybrid 18-molybdodiphosphate nanoparticles.

  17. Analysis of oxyhalide disinfection by-products and other anions of interest in drinking water by ion chromatography.

    Science.gov (United States)

    Hautman, D P; Bolyard, M

    1992-06-01

    The US Environmental Protection Agency is developing regulations for various drinking water disinfection by-products (DBPs). This effort involves developing analytical methods for the DBPs formed as a result of different disinfection treatments and collecting occurrence data for these species. Ion chromatography is one method being used to analyze drinking water samples for the following inorganic DBPs: chlorite, chlorate and bromate. These anions, however, are difficult to separate from common interfering anions of chloride, carbonate and nitrate. A method is therefore presented by which tetraborate/boric acid is used to separate these anions. Method detection limits of the order of 10 micrograms/l, using conductivity and UV detection were obtained. Stability studies of chlorite showing the effectiveness of ethylenediamine as a preservative and summary data for an occurrence of nitrite, nitrate and the DBP precursor bromide are presented.

  18. Kinetic spectrophotometric determination of bromide in clidinium-c drug

    Institute of Scientific and Technical Information of China (English)

    Ali Sheibani; M. Reza Shishehbore; Zahra Tavakolian Ardakani

    2011-01-01

    A simple, rapid and sensitive method has been described for the determination of the trace amounts of bromide. The method is based on the catalytic effect of bromide ion on the oxidation of methylene blue by bromate in sulfuric acid media. The reaction is monitored spectrophotometrically by measuring the decrease in the absorbance of methylene blue at 665 nm. Bromide was determined in the range of 0.05-1.90 μg/mL with the detection limit of 0.03 μg/mL. The relative standard deviations of five replicate determinations of 0.20 and 10.0 μg/mL of bromide were 2.4% and 1.8%, respectively. The influence of potential interfering ions and substances was studied. The method is applied to the analysis of bromide in clidinium-c tablet as a real sample.

  19. Disinfection by-products in ballast water treatment: an evaluation of regulatory data.

    Science.gov (United States)

    Werschkun, Barbara; Sommer, Yasmin; Banerji, Sangeeta

    2012-10-15

    To reduce the global spread of invasive aquatic species, international regulations will soon require reductions of the number of organisms in ballast water discharged by ships. For this purpose, ballast water treatment systems were developed and approved by an international procedure. These systems rely on established water treatment principles which, to different degrees, have been proven to generate disinfection by-products with hazardous properties but have only scarcely been investigated in marine environments. Our study evaluates the publicly available documentation about approved ballast water treatment systems with regard to by-product formation. The most commonly employed methods are chlorination, ozonation, and ultraviolet (UV) irradiation. Chlorination systems generate trihalomethanes, halogenated acetic acids, and bromate in substantially larger quantities than reported for other areas of application. Levels are highest in brackish water, and brominated species predominate, in particular bromoform and dibromoacetic acid. Ozonation, which is less frequently utilized, produces bromoform in lower concentrations but forms higher levels of bromate, both of which were effectively reduced by active carbon treatment. In systems based on UV radiation, medium pressure lamps are employed as well as UV-induced advanced oxidation. For all UV systems, by-product formation is reported only occasionally. The most notable observations were small increases in nitrite, hydrogen peroxide, halogenated methanes and acetic acids. The assessment of by-product formation during ballast water treatment is limited by the lacking completeness and quality of available information. This concerns the extent and statistical characterisation of chemical analysis as well as the documentation of the test water parameters.

  20. pH oscillations in the BrO3--SO3(2-)/HSO3- reaction in a CSTR.

    Science.gov (United States)

    Szantó, Tibor G; Rabai, Gyula

    2005-06-23

    Large-amplitude pH oscillations have been measured during the oxidation of sulfur (IV) species by the bromate ion in aqueous solution in a continuous-flow stirred tank reactor in the absence of any additional oxidizing or reducing reagent. The source of the oscillation in this simple chemical reaction is a two-way oxidation of sulfur (IV) by the bromate ion: (1) the hydrogen-ion-producing self-accelerating oxidation to sulfur (VI) (SO4(2-)), and (2) a hydrogen-ion-consuming oxidation to sulfur (V) (S2O6(2-)). In such a way, both the H+-producing and H+-consuming composite processes required for a pH oscillator take place in parallel in a reaction between two reagents in this system. A simple reaction scheme, consisting of the protonation equilibria of SO3(2-) and HSO3-, the oxidation of HSO3- and H2SO3 by BrO3- to SO4(2-), and the oxidation of H2SO3 to S2O6(2-) has successfully been used to simulate the observed dynamical behavior. Simulation with this simple scheme shows that oscillations can be calculated even if only about 1% of sulfur (IV) is oxidized to S2O6(2-) along with the main product SO4(2-). Agreement between calculated and measured dynamical behavior is found to be quite good. Increasing temperature decreases both the period length of oscillations in a CSTR and the Landolt time measured in a closed reactor. No temperature compensation of the oscillatory frequency is found in this reaction.

  1. UTILIZATION OF BROMINATION REACTION FOR THE SPECTROPHOTOMETRIC ASSAY OF DOMPERIDONE IN PHARMACEUTICALS

    Directory of Open Access Journals (Sweden)

    O. ZENITA DEVI

    2011-03-01

    Full Text Available Three simple and sensitive spectrophotometric methods are described for the determination of domperidone (DOM in bulk drug and in dosage forms using bromate-bromide mixture as brominating agent in acid medium and three dyes, meta-cresol purple (MCP, amaranth (AMR and erioglaucine (EGC. The methods involve the addition of a known excess of bromate-bromide mixture to an acidified solution of DOM followed by the determination of the residual bromine by reacting with a fixed amount of either MCP dye and measuring the absorbance at 530 nm (method A or AMR dye and measuring the absorbance at 520 nm (method B or EGC dye and measuring the absorbance at 630 nm (method C. Beer’s law is obeyed over the concentration ranges, 0.63–10.0, 0.25-4.0 and 0.13-2.0 µg mL-1 for method A, B and C, respectively. The ap¬parent molar absorptivities are calculated to be 3.751x104, 6.604x104 and 1.987x105 L mol-1cm-1 for method A, B and C, respectively, and the corresponding sandell sensitivity values are 0.011, 0.006 and 0.002 μg cm-2. The limit of detection and the limit of quantification are also reported for all the three methods. No interference was observed from common additives found in pharmaceutical preparations. Statistical comparisons of the results with those of the reference method showed excellent agreement, and indicated no significant difference in accuracy and precision. The accuracy and reliability of the methods were further ascertained by performing recovery tests via standardaddition technique.

  2. Organic Contaminant Abatement in Reclaimed Water by UV/H2O2 and a Combined Process Consisting of O3/H2O2 Followed by UV/H2O2: Prediction of Abatement Efficiency, Energy Consumption, and Byproduct Formation.

    Science.gov (United States)

    Lee, Yunho; Gerrity, Daniel; Lee, Minju; Gamage, Sujanie; Pisarenko, Aleksey; Trenholm, Rebecca A; Canonica, Silvio; Snyder, Shane A; von Gunten, Urs

    2016-04-01

    UV/H2O2 processes can be applied to improve the quality of effluents from municipal wastewater treatment plants by attenuating trace organic contaminants (micropollutants). This study presents a kinetic model based on UV photolysis parameters, including UV absorption rate and quantum yield, and hydroxyl radical (·OH) oxidation parameters, including second-order rate constants for ·OH reactions and steady-state ·OH concentrations, that can be used to predict micropollutant abatement in wastewater. The UV/H2O2 kinetic model successfully predicted the abatement efficiencies of 16 target micropollutants in bench-scale UV and UV/H2O2 experiments in 10 secondary wastewater effluents. The model was then used to calculate the electric energies required to achieve specific levels of micropollutant abatement in several advanced wastewater treatment scenarios using various combinations of ozone, UV, and H2O2. UV/H2O2 is more energy-intensive than ozonation for abatement of most micropollutants. Nevertheless, UV/H2O2 is not limited by the formation of N-nitrosodimethylamine (NDMA) and bromate whereas ozonation may produce significant concentrations of these oxidation byproducts, as observed in some of the tested wastewater effluents. The combined process of O3/H2O2 followed by UV/H2O2, which may be warranted in some potable reuse applications, can achieve superior micropollutant abatement with reduced energy consumption compared to UV/H2O2 and reduced oxidation byproduct formation (i.e., NDMA and/or bromate) compared to conventional ozonation. PMID:26909504

  3. Induction and repair of DNA damage measured by the comet assay in human T lymphocytes separated by immunomagnetic cell sorting.

    Science.gov (United States)

    Bausinger, Julia; Speit, Günter

    2014-11-01

    The comet assay is widely used in human biomonitoring to measure DNA damage in whole blood or isolated peripheral blood mononuclear cells (PBMC) as a marker of exposure to genotoxic agents. Cytogenetic assays with phytohemagglutinin (PHA)-stimulated cultured T lymphocytes are also frequently performed in human biomonitoring. Cytogenetic effects (micronuclei, chromosome aberrations, sister chromatid exchanges) may be induced in vivo but also occur ex vivo during the cultivation of lymphocytes as a consequence of DNA damage present in lymphocytes at the time of sampling. To better understand whether DNA damage measured by the comet assay in PBMC is representative for DNA damage in T cells, we comparatively investigated DNA damage and its repair in PBMC and T cells obtained by immunomagnetic cell sorting. PBMC cultures and T cell cultures were exposed to mutagens with different modes of genotoxic action and DNA damage was measured by the comet assay after the end of a 2h exposure and after 18h post-incubation. The mutagens tested were methyl methanesulfonate (MMS), (±)-anti-B[a]P-7,8-dihydrodiol-9,10-epoxide (BPDE), 4-nitroquinoline-1-oxide (4NQO), styrene oxide and potassium bromate. MMS and potassium bromate were also tested by the modified comet assay with formamido pyrimidine glycosylase (FPG) protein. The results indicate that the mutagens tested induce DNA damage in PBMC and T cells in the same range of concentrations and removal of induced DNA lesions occurs to a comparable extent. Based on these results, we conclude that the comet assay with PBMC is suited to predict DNA damage and its removal in T cells.

  4. Preparation and electrocatalytic application of composites containing gold nanoparticles protected with rhodium-substituted polyoxometalates

    International Nuclear Information System (INIS)

    Substitution of a metal center of phosphomolybdate, PMo12O403- (PMo12), or its tungsten analogue with dirhodium(II) and subsequent stabilization of gold nanoparticles, AuNPs, with Rh2PMo11 are demonstrated. The AuNP-Rh2PMo11 mediates oxidations but adsorbs too weakly for direct modification of electrode materials. Stability in quiescent solution was achieved by modifying glassy carbon (GC) with 3-aminopropyltriethoxysilane (APTES) and then electrostatically assembling AuNP-Rh2PMo11. At GC|APTES|AuNP-Rh2PMo11, cyclic voltammetry showed the expected set of three reversible peak-pairs for PMo11 in the range -0.2 to 0.6 vs. (Ag/AgCl)/V and the reversible RhII,III couple at 1.0 vs. (Ag/AgCl)/V. The presence of AuNPs increased the current for the reduction of bromate by a factor of 2.5 relative to that at GC|Rh2PMo11, and the electrocatalytic oxidation of methionine displayed characteristics of synergism between the AuNP and RhII. To stabilize AuNP-Rh2PMo11 on a surface in a flow system, GC was modified by electrochemically assisted deposition of a sol-gel with templated 10-nm pores prior to immobilizing the catalyst in the pores. The resulting electrode permitted determination of bromate by flow-injection amperometry with a detection limit of 4.0 x 10-8 mol dm-3.

  5. Use of a molecular beacon to track the activity of base excision repair protein OGG1 in live cells.

    Science.gov (United States)

    Mirbahai, Leda; Kershaw, Rachael M; Green, Richard M; Hayden, Rachel E; Meldrum, Rosalind A; Hodges, Nikolas J

    2010-02-01

    An abundant form of DNA damage caused by reactive oxygen species is 8-oxo-7,8-dihydroguanine for which the base excision repair protein 8-oxoguanine-DNA glycosylase 1 (OGG1) is a major repair enzyme. To assess the location and intracellular activity of the OGG1 protein in response to oxidative stress, we have utilised a fluorescence-quench molecular beacon switch containing a 8-oxo-dG:C base pair and a fluorescent and quencher molecule at opposite ends of a hairpin oligonucleotide. Oxidative stress was induced by treatment with potassium bromate. Flow cytometry demonstrated a concentration-dependent increase in the activity of OGG1 that was detected by the fluorescence produced when the oligonucleotide was cleaved in the cells treated with potassium bromate. This signal is highly specific and not detectable in OGG1 knock out cells. Induction of OGG1 activity is not a result of induction of OGG1 gene expression as assessed by qPCR suggesting a role for protein stabilisation or increased OGG1 catalytic activity. High resolution confocal microscopy pinpointed the location of the fluorescent molecular beacon in live cells to perinuclear regions that were identified as mitochondria by co-staining with mitotracker dye. There is no evidence of cut beacon within the nuclear compartment of the cell. Control experiments with a positive control beacon (G:C base pair and lacking the DAB quencher) did not result in mitochondrial localisation of fluorescence signal indicating that the dye does not accumulate in mitochondria independent of OGG1 activity. Furthermore, faint nuclear staining was apparent confirming that the beacon structure is able to enter the nucleus. In conclusion, these data indicate that the mitochondria are the major site for OGG1 repair activity under conditions of oxidative stress.

  6. Preparation and Electrocatalytic Application of Composites Containing Gold Nanoparticles Protected with Rhodium-Substituted Polyoxometalates

    Science.gov (United States)

    Wiaderek, Kamila M.; Cox, James A.

    2010-01-01

    Substitution of a metal center of phosphomolybdate, PMo12O403- (PMo12), or its tungsten analogue with dirhodium(II) and subsequent stabilization of gold nanoparticles, AuNPs, with Rh2PMo11 is demonstrated. The AuNP-Rh2PMo11 mediates oxidations but adsorbs too weakly for direct modification of electrode materials. Stability in quiescent solution was achieved by modifying glassy carbon (GC) with 3-aminopropyltriethoxysilane (APTES) and then electrostatically assembling AuNP-Rh2PMo11. At GC|APTES|AuNP-Rh2PMo11, cyclic voltammetry showed the expected set of three reversible peak-pairs for PMo11 in the range -0.2 to 0.6 vs (Ag/AgCl)/V and the reversible RhII,III couple at 1.0 vs (Ag/AgCl)/V. The presence of AuNPs increased the current for the reduction of bromate by a factor of 2.5 relative to that at GC|Rh2PMo11, and the electrocatalytic oxidation of methionine displayed characteristics of synergism between the AuNP and RhII. To stabilize AuNP-Rh2PMo11 on a surface in a flow system, GC was modified by electrochemically assisted deposition of a sol-gel with templated 10-nm pores prior to immobilizing the catalyst in the pores. The resulting electrode permitted determination of bromate by flow-injection amperometry with a detection limit of 4.0 × 10-8 mol dm-3. PMID:21499522

  7. Preparation and Electrocatalytic Application of Composites Containing Gold Nanoparticles Protected with Rhodium-Substituted Polyoxometalates.

    Science.gov (United States)

    Wiaderek, Kamila M; Cox, James A

    2011-04-01

    Substitution of a metal center of phosphomolybdate, PMo(12)O(40) (3-) (PMo(12)), or its tungsten analogue with dirhodium(II) and subsequent stabilization of gold nanoparticles, AuNPs, with Rh(2)PMo(11) is demonstrated. The AuNP-Rh(2)PMo(11) mediates oxidations but adsorbs too weakly for direct modification of electrode materials. Stability in quiescent solution was achieved by modifying glassy carbon (GC) with 3-aminopropyltriethoxysilane (APTES) and then electrostatically assembling AuNP-Rh(2)PMo(11). At GC|APTES|AuNP-Rh(2)PMo(11), cyclic voltammetry showed the expected set of three reversible peak-pairs for PMo(11) in the range -0.2 to 0.6 vs (Ag/AgCl)/V and the reversible Rh(II,III) couple at 1.0 vs (Ag/AgCl)/V. The presence of AuNPs increased the current for the reduction of bromate by a factor of 2.5 relative to that at GC|Rh(2)PMo(11), and the electrocatalytic oxidation of methionine displayed characteristics of synergism between the AuNP and Rh(II). To stabilize AuNP-Rh(2)PMo(11) on a surface in a flow system, GC was modified by electrochemically assisted deposition of a sol-gel with templated 10-nm pores prior to immobilizing the catalyst in the pores. The resulting electrode permitted determination of bromate by flow-injection amperometry with a detection limit of 4.0 × 10(-8) mol dm(-3).

  8. VARIATION OF DISINFECTION BYPRODUCTS(DBPs)IN THE WATER PLANT USING PRE-OZONATION TREATMENT%水厂预臭氧化处理过程中消毒副产物的变化研究

    Institute of Scientific and Technical Information of China (English)

    李思思; 何凤华; 钟晓; 孙淑琴; 翟利芳; 王启山

    2012-01-01

    Study on the variation of disinfection byproducts (DBPs) in a water plant, which treated Luan River by preozonalion-UV+chlorine disinfection technics. THMFP. HAAFP, fonnaldehyde, and bromate in effluent water were detected. The results showed that preozonation can reduce THMFP and HAAFP, the average removal rate were 22.76% and 2238% separately; and it reached up to 46.23% and 55.38% after the whole processes. Though the concentration of fonnaldehyde increased after treated by pre-ozonation, it was significantly reduced in the following process. No bromate was detected in the effluent water.%以滦河水为处理对象,对天津市某水厂预臭氧化-紫外+氯联合消毒工艺处理过程中的氯化消毒副产物和臭氧副产物的变化情况进行了分析研究.分别对各处理单元出水中的三卤甲烷生成势(THMFP)、卤乙酸生成势(HAAFP)、甲醛、溴酸盐的含量进行检测.结果表明,原水经过预臭氧化处理后,THMFP和HAAFP的质量浓度均有降低,预臭氧处理单元对THMFP和HAAFP的平均去除率分别为22.76%和22.38%;整套工艺对THMFP和HAAFP的平均去除率分别可达46.23%和55.38%.经预臭氧化处理后,甲醛的浓度上升,但后续工艺对甲醛的去除效果较好,未出现溴酸盐超标.

  9. Simultaneous Removal of Selected Oxidized Contaminants from Groundwater with a Hydrogen-based Membrane Biofilm Reactor%利用氢基质生物膜反应器同步去除多种污染物

    Institute of Scientific and Technical Information of China (English)

    夏四清; 梁郡; 李海翔; 徐晓茵

    2012-01-01

    利用氢基质生物膜反应器(hydrogen-based membrane biofilm reactor,MBfR)对含有多种氧化性污染物包括硝酸盐(NO3- - N)、硫酸盐(SO42-)、溴酸盐(BrO3-)、六价铬(Cr(Ⅵ))和对氯硝基苯(p-CNB)的模拟地下水进行同步去除试验研究.结果表明,MBfR中生长于中空纤维膜表面的氢自养还原菌利用氢气作为电子供体进行自养还原反应,将水中NO3-N还原成N2,SO42-还原成硫化物(S2-/H2S),BrO3-还原成Br-,Cr(Ⅵ)还原成Cr(Ⅲ),p-CNB逐步还原成对氯苯铵(p-CAN)和苯胺(AN).通过生物还原达到对氧化性污染物的去除或毒性的降低.在氢分压为0.06 MPa和水力停留时间为4.67 h条件下,经过生物膜驯化及32 d的连续运行,反应器对各种氧化性污染物的去除性能达到稳定:NO3--N和BrO3-近于完全去除,SO42-去除率达19.8%,Cr(Ⅵ)去除率达85.8%,p-CNB去除率达86.1%.研究表明,利用氢基质生物膜反应器处理含多种氧化性污染物的地下水可行,且具有一定应用潜力.%A hydrogen-based membrane biofilm reactor (MBfR) was applied for simultaneous biodegradation of selected oxidized contaminants in groundwater including nitrate (NO3-- N), sulfate (SO42-),bromate (BrO3-), chromate (Cr(Ⅵ)) and para-chloronitrobenzene (p-CNB). The autohydrogentrophic bacteria lived on the membrane surface bioreduced nitrate to N2, sulfate to sulfide (S2-/ HM2S), bromate to bromide ion (Br-), Cr(Ⅵ) to Cr(Ⅲ) and p- CNB to p- CAN and AN with hydrogen as electron donor. Removal and/or toxicity decrease of these oxidized contaminates was achieved through biological reduction. After biofilm enrichment and 32 d continuous running, the reactor reached a steady state for removing oxidized contaminates with a nearly complete removal for nitrate and bromate, 19.8% for sulfate, 85. 6% for chromate, and 86. 1% for p-CNB, under the hydrogen pressure at 0. 06 MPa and hydraulic retention time at 4.67 h. The results show that the MBfR technology can

  10. 饮用水中草甘膦的离子色谱法测定%Determination of Glyphosate in Drinking Water

    Institute of Scientific and Technical Information of China (English)

    吴燕琴; 郭梁钻; 谢丽章

    2012-01-01

    目的:建立一次进样同时测定饮用水中溴酸盐、草甘膦的离子色谱测定法。方法:选用DIONEX ICS-2000型离子色谱仪,用离子色谱法测定饮用水氟离子、溴酸盐、氯离子、溴离子、硝酸盐氮、硫酸盐、磷酸盐和草甘膦等离子,分离效果理想、灵敏度较高。进样量100μL。结果溴酸盐、溴离子、磷酸盐、草甘膦的检出限分别为:4.0μg/L、4.0μg/L、5.2μg/L、4.4μg/L;标准偏差〈5%;样品加标回收率在88.0%~104.0%之间。结论:该方法操作简单,分析快速,灵敏度高,重现性好,能够准确检测水中草甘膦含量。%Objective: A novel method covered the determination of the bromate and glyphosate in drinking water by chemically and electrolytically suppressed ion chromatography.Results: The detection limits for bromate,bromine ion,phosphate and glyphosate was 4.0 μg/L、4.0 μg/L、5.2 μg/L、4.4 μg/L.The RSD 5 %,and the recoveries of the method for them were between 88.0 %~104.0 %.Conclusion: The method established in the present paper was simple,precise,sensitive and suitable for determination of glyphosate.Its advantages were simple operation,speediness,high sensitivity,good repeatability.

  11. Analysis of Diurnal Variations in Energy Footprint and Its Associated Carbon Emission for Water Supply and Reuse in Arid and Semi-Arid Areas

    Science.gov (United States)

    Sobhani, Reza

    characterized by water scarcity, such as Southern California, groundwater containing chromophoric dissolved organic matter is a viable source of water supply. However, the seawater intrusion increased the concentration of bromide in extracted groundwater. Bromide, a precursor to bromate formation is regulated by USEPA as a potential carcinogen. This study compares the energy footprint among the two processes utilized for treatment of highly colored groundwater (i.e. nanofiltration and ozone injection coupled with biologically activated carbon) and discusses the impacts of bromate formation among these processes.

  12. 3种填料有机物和氨氮去除性能及吸附效果比较%ORGANIC MATTER AND AMMONIA REMOVAL AND ADSORPTION ABILITY OF THREE KINDS OF CARRIERS

    Institute of Scientific and Technical Information of China (English)

    李朋; 汪群慧; 郑天龙; 谢维民

    2012-01-01

    Study on the variation of disinfection byproducts (DBPs) in a water plant, which treated Luan River by preozonalion-UV+chlorine disinfection technics. THMFP. HAAFP, fonnaldehyde, and bromate in effluent water were detected. The results showed that preozonation can reduce THMFP and HAAFP, the average removal rate were 22.76% and 2238% separately; and it reached up to 46.23% and 55.38% after the whole processes. Though the concentration of fonnaldehyde increased after treated by pre-ozonation, it was significantly reduced in the following process. No bromate was detected in the effluent water.%考察了海绵球形填料、螺旋形填料和纤维球填料的处理效果及吸附性能.结果表明,常温低填充比(15~20℃,13.75%)时,螺旋形填料COD平均去除率最高,可达到97%以上,3种填料氨氮平均去除率均可达到99%以上.海绵球形填料受填充比影响较小,而填充比过高会影响螺旋形填料和纤维球填料的传质布气效果.纤维球具有巨大的比表面积,吸附性能较强,单位体积附着污泥量可达22.97 g/L,且其吸附性能受温度影响小.螺旋形填料单位比表面积附着污泥量为0.042g·m3/m2,其吸附性能与其表面电荷和构型有关.海绵球形填料单位质量填料附着污泥量高,在相同要求下需要填料质量小,运输和安装时可节约成本.

  13. 预臭氧化工艺对消毒副产物影响的生产性研究%Full-scale study on effects of pre-ozonation on disinfection by - products

    Institute of Scientific and Technical Information of China (English)

    岳尚超; 王启山; 张伟林; 李思思; 张怡然; 刘艳芳; 鲁金凤; 赵文玉

    2012-01-01

    通过进行预臭氧化一紫外线联合氯消毒工艺处理高温高藻期滦河水的生产性试验,检测和分析三卤甲烷生成势(THMFP)和卤乙酸生成势(HAAFP)的含量变化情况,研究了整套水处理工艺,尤其是预臭氧化单元对氯消毒副产物(DBPs)的去除效果.同时,研究了甲醛和溴酸盐这两种臭氧化副产物在处理过程中的生成情况.结果表明:在高温高藻期,预臭氧化单元对THMFP和HAAFP的平均去除率分别为12.43%和15.06%,整套工艺对THMFP和HAAFP的平均总去除率分别为39.33%和54.12%,氯消毒副产物前体物得到有效去除;出水中甲醛含量低于50μg/L,溴酸盐的含量小于6μg/L,臭氧氧化副产物得到了有效控制.%A full-scale study was done on the processes of pre-ozonation and a combination disinfection of ultraviolet and chlorine to treat the Luan River raw water in high temperature and high algae concentration phase. Through the testing and analyzing of the trihalomethanes formation potential (THMFP) and haloacetic acids formation potential (HAAFP) variances, the whole set of water treatment process was studied, especially the effects of pre-ozonation on disinfection byproducts (DBPs) removal. At the same time, the formation of formaldehyde and bromated in treatment process was also studied. The results showed: during high temperature and high algae concentration period, the average removal rates of THMFP and HAAFP by pre-ozonation were 12. 43% and 15. 06% respectively, and the removal rates of combined process were 39. 33% and 54. 12% respectively, which meant the precursors of DBPs were removed effectively; formaldehyde and bromate in effluent were less than 50 μg/L and 6 μg/L respectively, which meant the DBPs were also controlled effectively.

  14. Reaction products from the chlorination of seawater. Final report 15 Jul 75-14 Jul 80

    Energy Technology Data Exchange (ETDEWEB)

    Carpenter, J.H.; Smith, C.A.; Zika, R.G.

    1981-03-01

    Chemical treatment of natural waters, in particular the use of chlorine as a biocide, modifies the chemistry of these waters in ways that are not fully understood. The research described in this report examined both inorganic and organic reaction products from the chlorination of seawater using a variety of analytical approaches. Some analytical methods in widespread current use underestimate the residual oxidants in chlorinated seawater by as much as 70% depending upon the detail of the procedures. The chlorination of seawater in the presence of light produces substantial quantities of bromate ions which can influence standard analytical procedures and represents an unknown factor in estuarine and coastal waters. The copper complexing capacity of Biscayne Bay, Florida water was found to be substantially reduced with the addition of chlorine. Analysis was made by anodic stripping voltammetry on water samples after successive additions of copper sulfate solution. Laboratory chlorination of water from the intake of the Port Everglades, Florida power plant produces bromoform levels comparable to that found in the plant discharge. These results are in contrast to results reported in the literature for a power plant on the Patuxent estuary in Maryland, so that bromoform production appears to be site-specific. Chloroform extracts of chlorinated Biscayne Bay water are found to contain halogenated compounds which are new and different, and which pose unusual analytical problems. Studies using GC/ECD, GC/MS, HPLC, H NMR, differential pulsed polarography and other techniques on natural extracts and synthesized compounds are reported.

  15. Formation of oxidation byproducts from ozonation of wastewater.

    Science.gov (United States)

    Wert, Eric C; Rosario-Ortiz, Fernando L; Drury, Doug D; Snyder, Shane A

    2007-04-01

    Disinfection byproduct (DBP) formation in tertiary wastewater was examined after ozonation (O(3)) and advanced oxidation with O(3) and hydrogen peroxide (O(3)/H(2)O(2)). O(3) and O(3)/H(2)O(2) were applied at multiple dosages to investigate DBP formation during coliform disinfection and trace contaminant oxidation. Results showed O(3) provided superior disinfection of fecal and total coliforms compared to O(3)/H(2)O(2). Color, UV absorbance, and SUVA were reduced by O(3) and O(3)/H(2)O(2), offering wastewater utilities a few potential surrogates to monitor disinfection or trace contaminant oxidation. At equivalent O(3) dosages, O(3)/H(2)O(2) produced greater concentrations of assimilable organic carbon (5-52%), aldehydes (31-47%), and carboxylic acids (12-43%) compared to O(3) alone, indicating that organic DBP formation is largely dependent upon hydroxyl radical exposure. Bromate formation occurred when O(3) dosages exceeded the O(3) demand of the wastewater. Bench-scale tests with free chlorine showed O(3) is capable of reducing total organic halide (TOX) formation potential by at least 20%. In summary, O(3) provided superior disinfection compared to O(3)/H(2)O(2) while minimizing DBP concentrations. These are important considerations for water reuse, aquifer storage and recovery, and advanced wastewater treatment applications.

  16. Oscillating chemiluminescence in rhodamine B-induced Belousov-Zhabotinsky reaction catalyzed by Ce(Ⅳ)

    Institute of Scientific and Technical Information of China (English)

    DUAN ChunFeng; LIU GuangMing; ZHANG ZhiFeng; CUI Hua

    2009-01-01

    It was found that rhodamine B could induce oscillating chemiluminescence (OCL) from the Ce4+-cata-lyzed Belousov-Zhabotinsky reaction. This new OCL system, i.e., rhodamine B-malonic acid-bromate-Ce(IV)-sulfuric acid, exhibited two clearly distinguished emission peaks in each oscillation period. The initial concentrations of the reactants strongly influenced the oscillation pattern. For the study of the CL mechanism, a platform for a versatile and simultaneous potential and CL measurement was estab-lished to compare the potential oscillation with the CL oscillation behavior of this system. The CL spectra, UV-visible absorption spectra and time-resolved fluorescence spectra of this OCL system were studied. A possible, simplified mechanism for the OCL is proposed. It is suggested that the generation of the two CL peaks is likely due to the oxidation of the intermediate of rhodamine B by Co(IV) and Br2, respectively. This work provided a new method and platform to research the complex chemical oscilla-tions.

  17. Rapid simultaneous analysis of 17 haloacetic acids and related halogenated water contaminants by high-performance ion chromatography-tandem mass spectrometry.

    Science.gov (United States)

    Xue, Runmiao; Donovan, Ariel; Shi, Honglan; Yang, John; Hua, Bin; Inniss, Enos; Eichholz, Todd

    2016-09-01

    Haloacetic acids (HAAs), which include chloroacetic acids, bromoacetic acids, and emerging iodoacetic acids, are toxic water disinfection byproducts. General screening methodology is lacking for simultaneously monitoring chloro-, bromo-, and iodoacetic acids. In this study, a rapid and sensitive high-performance ion chromatography-tandem mass spectrometry method for simultaneous determination of chloro-, bromo-, and iodo- acetic acids and related halogenated contaminants including bromate, bromide, iodate, and iodide was developed to directly analyze water samples after filtration, eliminating the need for preconcentration, and chemical derivatization. The resulting method was validated in both untreated and treated water matrices including tap water, bottled water, swimming pool water, and both source water and drinking water from a drinking water treatment facility to demonstrate application potential. Satisfactory accuracies and precisions were obtained for all types of tested samples. The detection limits of this newly developed method were lower or comparable with similar techniques without the need for extensive sample treatment requirement and it includes all HAAs and other halogenated compounds. This provides a powerful methodology to water facilities for routine water quality monitoring and related water research, especially for the emerging iodoacetic acids. Graphical abstract High performance ion chromatography-tandem mass spectrometry method for detection of haloacetic acids in water.

  18. Flow injection kinetic spectrofluorimetric determination of trace amounts of osmium

    Science.gov (United States)

    Tang, Bo; Zhang, Hui; Wang, Yan

    2005-07-01

    A flow injection (FI) kinetic spectrofluorimetric method is described for the determination of osmium(IV) and the possible mechanism of catalytic reaction is discussed. The method is based on the fluorescence enhancing reaction of o-vanillin furfuralhydrazone (OVFH) with potassium bromate, which is catalyzed by Os(IV) in water medium at pH 6.10 and 45 °C. OVFH is newly synthesized and its ionization, IR and elemental analysis are established. Under these experimental conditions, the oxidized product of OVFH has excitation and emission maxima at 337 and 490 nm, respectively. The linear range of this method is 0-600 ng ml -1 with the R.S.D. of 1.2%. The detection limit is 1.0 ng ml -1 of Os(IV). A high analysis rate of 24 samples h -1 is obtained by the FI method. The proposed method is applied successfully to determine Os(IV) in synthetic mixture and mineral samples, and the results are well consistent with the standard values.

  19. Determination of caffeine using oscillating chemical reaction in a CSTR.

    Science.gov (United States)

    Gao, Jinzhang; Ren, Jie; Yang, Wu; Liu, XiuHui; Yang, Hua

    2003-07-14

    A new analytical method for the determination of caffeine by the sequential perturbation caused by different amounts of caffeine on the oscillating chemical system involving the manganese(II)-catalyzed reaction between potassium bromate and tyrosine in acidic medium in a CSTR was proposed. The method exposed for the first time in this work. It relies on the relationship between the changes in the oscillation amplitude of the chemical system and the concentration of caffeine. The calibration curve fits a second-order polynomial equation very well when the concentration of caffeine over the range 4.0 x 10(-6) - 1.2 x 10(-4) M (r = 0.9968). The effect of influential variables, such as the concentration of reaction components, injection point, temperature, flow rate and stirring rate were studied. Some aspects of the potential mechanism of action of caffeine on the chemical oscillating system were also discussed. A real sample was determined and the result was satisfactory.

  20. pH-oscillations in the bromate–sulfite reaction in semibatch and in gel-fed batch reactors

    Energy Technology Data Exchange (ETDEWEB)

    Poros, Eszter; Kurin-Csörgei, Krisztina; Szalai, István; Orbán, Miklós, E-mail: orbanm@chem.elte.hu [Department of Analytical Chemistry, Institute of Chemistry, L. Eötvös University, P.O. Box 32, H-1518 Budapest 112 (Hungary); Rábai, Gyula [Institute of Physical Chemistry, University of Debrecen, P.O. Box 7, H-4010 Debrecen (Hungary)

    2015-06-15

    The simplest bromate oxidation based pH-oscillator, the two component BrO{sub 3}{sup −}–SO{sub 3}{sup 2–} flow system was transformed to operate under semibatch and closed arrangements. The experimental preconditions of the pH-oscillations in semibatch configuration were predicted by model calculations. Using this information as guideline large amplitude (ΔpH∼3), long lasting (11–24 h) pH-oscillations accompanied with only a 20% increase of the volume in the reactor were measured when a mixture of Na{sub 2}SO{sub 3} and H{sub 2}SO{sub 4} was pumped into the solution of BrO{sub 3}{sup −} with a very low rate. Batch-like pH-oscillations, similar in amplitude and period time appeared when the sulfite supply was substituted by its dissolution from a gel layer prepared previously in the reactor in presence of high concentration of Na{sub 2}SO{sub 3}. The dissolution vs time curve and the pH-oscillations in the semibatch and closed systems were successfully simulated. Due to the simplicity in composition and in experimental technique, the semibatch and batch-like BrO{sub 3}{sup −}–SO{sub 3}{sup 2–} pH-oscillators may become superior to their CSTR (continuous flow stirred tank reactor) version in some present and future applications.

  1. A model for imperfect mixing in a CSTR

    Science.gov (United States)

    Bar-Eli, Kedma; Noyes, Richard M.

    1986-09-01

    When a chemical reaction is carried out in a continuously stirred tank reactor, the behavior may be significantly affected by the efficiency with which the entering chemicals are mixed with the main contents of the reactor. We have developed a model for this effect which assumes that a feed of premixed chemicals remains for a while in totally segregated packets before they are rapidly and perfectly mixed with the rest of the system. The time of this initial segregation is affected by the efficiency of stirring in the reactor. The model has been tested by computations on a mechanism developed by Roelofs et al. for a reaction which would oscillate even in a closed system. It has also been tested by computations on the rapid autocatalytic oxidation of cerous ion by bromate in the presence of a small amount of bromide. The results are qualitatively consistent with effects observed experimentally and in computations with other models including a somewhat similar one by Kumpinsky and Epstein. More quantitative tests should recognize the difference whether two streams of chemicals enter the reactor independently or are premixed before they do so.

  2. Exposure to mutagenic disinfection byproducts leads to increase of antibiotic resistance in Pseudomonas aeruginosa.

    Science.gov (United States)

    Lv, Lu; Jiang, Tao; Zhang, Shenghua; Yu, Xin

    2014-07-15

    Bacterial antibiotic resistance (BAR) in drinking water has become a global issue because of its risks on the public health. Usually, the antibiotic concentrations in drinking water are too low to select antibiotic resistant strains effectively, suggesting that factors other than antibiotics would contribute to the emergence of BAR. In the current study, the impacts of mutagenic disinfection byproducts (DBPs) on BAR were explored, using four typical DBPs: dibromoacetic acid, dichloroacetonitrile, potassium bromate, and 3-chloro-4-(dichloromethyl)-5-hydroxy-2(5H)-furanone (MX). After exposure to DBPs, resistances to 10 individual antibiotics and multiple antibiotics were both raised by various levels, norfloxacin and polymycin B resistances were enhanced even greater than 10-fold compared with control. MX increased the resistance most observably in the selected DBPs, which was consistent with its mutagenic activity. The resistant mutants showed hereditary stability during 5-day culturing. The increase of BAR was caused by the mutagenic activities of DBPs, since mutation frequency declined by adding ROS scavenger. Mutagenesis was further confirmed by sequencing of the related genes. Our study indicated that mutagenic activities of the selected DBPs could induce antibiotic resistance, even multidrug resistance, which may partially explain the lack of agreement between BAR and antibiotic levels in drinking water.

  3. Inactivation of invasive marine species in the process of conveying ballast water using OH based on a strong ionization discharge.

    Science.gov (United States)

    Bai, Mindong; Zheng, Qilin; Tian, Yiping; Zhang, Zhitao; Chen, Cao; Cheng, Chao; Meng, Xiangying

    2016-06-01

    In this paper, invasive marine species in medium-salinity ballast water were inactivated using OH generated from a strong ionization discharge. The OH is determined by the concentration of oxygen active species combined with the effects of water jet cavitation. The results indicated that the OH concentration reached 7.62 μM, within 1 s, which is faster and higher than in conventional AOP methods. In a pilot-scale OH ballast water system with a capacity of 10 m(3)/h, algae were inactivated when CT value was 0.1 mg min/L with a contact time only 6 s. The viable and nonviable cells were determined using SYTOX Green nucleic acid stain and Flow cytometry. As a result, the OH treatment could be completed during the process of conveying the ballast water. In addition, the concentrations of relevant disinfection by-products (DBPs), such as trihalomethanes (THMs), haloacetic acids (HAAs), and bromate, were less than that required by the World Health Organization's drinking water standards, which suggest that the discharged ballast water posed no risks to the oceanic environment. Nevertheless, for conventional ozonation and electrolysis methods, the ballast water should be treated only in the treated tanks during the ship's voyage and form higher level DBPs.

  4. Laser-induced removal of a dye C.I. Acid Red 87 using n-type WO{sub 3} semiconductor catalyst

    Energy Technology Data Exchange (ETDEWEB)

    Qamar, M. [Center of Excellence in Nanotechnology, King Fahd University of Petroleum and Minerals, KFUPM Box 741, Dhahran 31261 (Saudi Arabia); Gondal, M.A., E-mail: magondal@kfupm.edu.sa [Center of Excellence in Nanotechnology, King Fahd University of Petroleum and Minerals, KFUPM Box 741, Dhahran 31261 (Saudi Arabia); Laser Research Laboratory, Physics Department, King Fahd University of Petroleum and Minerals, Dhahran 31261 (Saudi Arabia); Hayat, K. [Chemistry Department, King Fahd University of Petroleum and Minerals, Dhahran 31261 (Saudi Arabia); Yamani, Z.H. [Center of Excellence in Nanotechnology, King Fahd University of Petroleum and Minerals, KFUPM Box 741, Dhahran 31261 (Saudi Arabia); Laser Research Laboratory, Physics Department, King Fahd University of Petroleum and Minerals, Dhahran 31261 (Saudi Arabia); Al-Hooshani, K. [Center of Excellence in Nanotechnology, King Fahd University of Petroleum and Minerals, KFUPM Box 741, Dhahran 31261 (Saudi Arabia); Chemistry Department, King Fahd University of Petroleum and Minerals, Dhahran 31261 (Saudi Arabia)

    2009-10-30

    Water contamination by organic substances such as dyes is of great concern worldwide due to their utilization in many industrial processes and environmental concerns. To cater the needs for waste water treatment polluted with organic dyes, laser-induced photocatalytic process was investigated for removal of a dye derivative namely Acid Red 87 using n-type WO{sub 3} semiconductor catalyst. The degradation was investigated in aqueous suspensions of tungsten oxide under different experimental conditions using laser instead of conventional UV lamp as an irradiation source. The degradation process was monitored by measuring the change in dye concentration as a function of laser irradiation time by employing UV spectroscopic analysis. The degradation of dye was studied by varying different parameters such as laser energy, reaction pH, substrate concentration, catalyst concentration, and in the presence of electron acceptors such as hydrogen peroxide (H{sub 2}O{sub 2}), and potassium bromate (KBrO{sub 3}). The degradation rates were found to be strongly dependent on all the above-mentioned parameters. Our experimental results revealed that the dye degradation process was very fast (within few minutes) under laser irradiation as compared to conventional setups using broad spectral lamps (hours or days) and this laser-induced photocatalytic degradation method could be an effective means to eliminate the pollutants present in liquid phase. The experience gained through this study could be beneficial for treatment of waste water contaminated with organic dyes and other organic pollutants.

  5. Preparation and characterization of poly(acrylic acid)-hydroxyethyl cellulose graft copolymer.

    Science.gov (United States)

    Abdel-Halim, E S

    2012-10-01

    Poly(acrylic acid) hydroxyethyl cellulose [poly(AA)-HEC] graft copolymer was prepared by polymerizing acrylic acid (AA) with hydroxyethyl cellulose (HEC) using potassium bromate/thiourea dioxide (KBrO(3)/TUD) as redox initiation system. The polymerization reaction was carried out under a variety of conditions including concentrations of AA, KBrO(3) and TUD, material to liquor ratio and polymerization temperature. The polymerization reaction was monitored by withdrawing samples from the reaction medium and measuring the total conversion. The rheological properties of the poly(AA)-HEC graft copolymer were investigated. The total conversion and rheological properties of the graft copolymer depended on the ratio of KBrO(3) to TUD and on acrylic acid concentration as well as temperature and material to liquor ratio. Optimum conditions of the graft copolymer preparation were 30 mmol KBrO(3) and 30 mmol TUD/100g HEC, 100% AA (based on weight of HEC), duration 2h at temperature 50 °C using a material to liquor ratio of 1:10. PMID:22840022

  6. FIA versatile system for spectrophotometric determinations of vanadium and molybdenum exploring the catalytic activities of V(V) and Mo(VI); Sistema FIA polivalente para determinacoes espectrofotometricas de vanadio e molibdenio explorando as atividades cataliticas de V(V) e Mo(VI)

    Energy Technology Data Exchange (ETDEWEB)

    Luca, Gilmara Caseri de

    1996-02-01

    A versatile system for chemical analysis by flow injection analysis was developed and applied for catalytic spectrophotometric determination of vanadium or molybdenum in metallic alloys. The selected methods were based upon indicator reactions chromotropic (CS)-bromate acid or hydrogen iodide-peroxide, respectively. Initially, a model system was proposed, in which common parameters for methods were studied. This included a re-sampling process in which high degrees of samples dilution were obtained. Other parameters such as concentrations and reagents addition order, reaction medium Ph, temperature and ionic power, as well as procedures for sample solubilization, were studied relating to each method. A mini-column with cationic exchanger resin (Dowex 50W-X8, 50-100 mesh, H{sup +} form) was used. The system for vanadium determination processes 120 samples by hour, consuming 2,0 mg CS and 10 mg K Br O{sub 3b}y determination. Concerning the method for molybdenum, the reagents consumption was 2,0 mg KI and 1,0 {mu}L of solution 30% H{sub 2}O{sub 2} by determination, since the analytic velocity was the same, in relation to vanadium.

  7. Oxidative Stress in the Carcinogenicity of Chemical Carcinogens

    Directory of Open Access Journals (Sweden)

    Hideki Wanibuchi

    2013-10-01

    Full Text Available This review highlights several in vivo studies utilizing non-genotoxic and genotoxic chemical carcinogens, and the mechanisms of their high and low dose carcinogenicities with respect to formation of oxidative stress. Here, we survey the examples and discuss possible mechanisms of hormetic effects with cytochrome P450 inducers, such as phenobarbital, a-benzene hexachloride and 1,1-bis(p-chlorophenyl-2,2,2-trichloroethane. Epigenetic processes differentially can be affected by agents that impinge on oxidative DNA damage, repair, apoptosis, cell proliferation, intracellular communication and cell signaling. Non-genotoxic carcinogens may target nuclear receptors and induce post-translational modifications at the protein level, thereby impacting on the stability or activity of key regulatory proteins, including oncoproteins and tumor suppressor proteins. We further discuss role of oxidative stress focusing on the low dose carcinogenicities of several genotoxic carcinogens such as a hepatocarcinogen contained in seared fish and meat, 2-amino-3,8-dimethylimidazo[4,5-f]quinoxaline, arsenic and its metabolites, and the kidney carcinogen potassium bromate.

  8. Oxidative Stress in the Carcinogenicity of Chemical Carcinogens

    Energy Technology Data Exchange (ETDEWEB)

    Kakehashi, Anna; Wei, Min [Department of Pathology, Osaka City University Graduate School of Medicine, 1-4-3 Asahi-machi, Abeno-Ku, Osaka 545-8585 (Japan); Fukushima, Shoji [Japan Bioassay Research Center, Japan Industrial Safety and Health Association, 2445 Hirasawa, Hadano, Kanagawa 257-0015 (Japan); Wanibuchi, Hideki, E-mail: wani@med.osaka-cu.ac.jp [Department of Pathology, Osaka City University Graduate School of Medicine, 1-4-3 Asahi-machi, Abeno-Ku, Osaka 545-8585 (Japan)

    2013-10-28

    This review highlights several in vivo studies utilizing non-genotoxic and genotoxic chemical carcinogens, and the mechanisms of their high and low dose carcinogenicities with respect to formation of oxidative stress. Here, we survey the examples and discuss possible mechanisms of hormetic effects with cytochrome P{sub 450} inducers, such as phenobarbital, α-benzene hexachloride and 1,1-bis(p-chlorophenyl)-2,2,2-trichloroethane. Epigenetic processes differentially can be affected by agents that impinge on oxidative DNA damage, repair, apoptosis, cell proliferation, intracellular communication and cell signaling. Non-genotoxic carcinogens may target nuclear receptors and induce post-translational modifications at the protein level, thereby impacting on the stability or activity of key regulatory proteins, including oncoproteins and tumor suppressor proteins. We further discuss role of oxidative stress focusing on the low dose carcinogenicities of several genotoxic carcinogens such as a hepatocarcinogen contained in seared fish and meat, 2-amino-3,8-dimethylimidazo[4,5-f]quinoxaline, arsenic and its metabolites, and the kidney carcinogen potassium bromate.

  9. Bayesian analysis of physiologically based toxicokinetic and toxicodynamic models.

    Science.gov (United States)

    Hack, C Eric

    2006-04-17

    Physiologically based toxicokinetic (PBTK) and toxicodynamic (TD) models of bromate in animals and humans would improve our ability to accurately estimate the toxic doses in humans based on available animal studies. These mathematical models are often highly parameterized and must be calibrated in order for the model predictions of internal dose to adequately fit the experimentally measured doses. Highly parameterized models are difficult to calibrate and it is difficult to obtain accurate estimates of uncertainty or variability in model parameters with commonly used frequentist calibration methods, such as maximum likelihood estimation (MLE) or least squared error approaches. The Bayesian approach called Markov chain Monte Carlo (MCMC) analysis can be used to successfully calibrate these complex models. Prior knowledge about the biological system and associated model parameters is easily incorporated in this approach in the form of prior parameter distributions, and the distributions are refined or updated using experimental data to generate posterior distributions of parameter estimates. The goal of this paper is to give the non-mathematician a brief description of the Bayesian approach and Markov chain Monte Carlo analysis, how this technique is used in risk assessment, and the issues associated with this approach. PMID:16466842

  10. Cloud point extraction of plutonium in environmental matrixes coupled to ICPMS and α spectrometry in highly acidic conditions.

    Science.gov (United States)

    Labrecque, Charles; Whitty-Léveillé, Laurence; Larivière, Dominic

    2013-11-01

    A new cloud point extraction procedure has been developed for the quantification of plutonium(IV) in environmental samples. The separation procedure can be either coupled to inductively coupled plasma mass spectrometry (ICPMS) or α spectrometry for plutonium quantification. The method uses a combination of selective ligand (P,P'-di(2-ethylhexyl) methanediphosphonic acid (H2DEH[MDP])) and micelle shielding by bromine formation to enable quantitative extraction of Pu in highly acidic solutions. Cross-optimization of all parameters (nonionic and ionic surfactant, chelating agent, bromate, bromide, and pH) led to optimal of the extraction conditions. Figures of merit of the method for the detection using α spectrometry and ICPMS are reported (limit of detection, limit of quantification, minimal detectable activity, and recovery). Quantitative extractions (>95%) were obtained for a wide variety of aqueous and digested samples (synthetic urine, wastewater, drinking water, seawater, and soil samples). The method features the first successful coupling between α spectrometry and cloud point extraction and is the first demonstration of CPE suitability with metaborate fusion as a sample preparation approach, techniques used extensively in nuclear industries.

  11. Evaluating hydraulic and disinfection efficiencies of a full-scale ozone contactor using a RANS-based modeling framework.

    Science.gov (United States)

    Zhang, Jie; Tejada-Martínez, Andrés E; Zhang, Qiong; Lei, Hongxia

    2014-04-01

    The capability of predicting hydraulic and disinfection efficiencies of ozone disinfection contactors is essential for evaluating existing contactors and improving future designs. Previous attempts based on ideal and non-ideal models for the hydraulics and simplified mechanisms for chemical reaction modeling have resulted in low accuracy and are restricted to contactors with simple geometries. This manuscript develops a modeling framework for the ozonation process by combining computational fluid dynamics (CFD) with a kinetics-based reaction modeling for the first time. This computational framework has been applied to the full-scale ozone contactor operated by the City of Tampa Water Department. Flow fields, residence time distribution, ozone concentration distribution, and concentration-contact time (CT) distribution within the contactor have been predicted via the computational framework. The predictions of ozone and bromate concentrations at sample points agree well with physical experimental data measured in the contactor. The predicted CT values at the contactor outlet demonstrate that the disinfection performance of the ozone contactor operated by the City of Tampa Water Department is sufficient to meet regulation requirements. The impact of seasonal flow rate change on disinfection performance is found to be significant and deserves attention during the management and operation of a water treatment plant.

  12. 脂肪氧合酶的研究及应用进展%Application and research progress of lipoxygenase

    Institute of Scientific and Technical Information of China (English)

    闫静芳; 王红霞; 郭玉鑫; 陆兆新; 吕凤霞; 王昱沣

    2013-01-01

      脂肪氧合酶广泛存在于植物和微生物中,作为面粉改良剂如溴酸钾和过氧化苯甲酰的潜在替代品,是绿色食品添加剂的研究热点。本文详细综述了脂肪氧合酶的发现历史、结构性质、应用、对粮食和果蔬保藏的影响及其提取方法,并阐明了其最新研究现状。%  Lipoxygenase widely exists in plants and microorganisms. As a potential substitutes of flour con-ditioner such as potassium bromate and benzoyl peroxide, it has been the research focus of green food additives. This paper reviewed the discovery history, structure, properties, application, extraction methods of lipoxygenase and its effects on the preservation of fruits and vegetables and research status.

  13. Nonequilibrium / nonlinear chemical oscillation in the virtual absence of gravity

    Science.gov (United States)

    Fujieda, S.; Mogami, Y.; Moriyasu, K.; Mori, Y.

    1999-01-01

    The Belousov-Zhabotinsky (BZ) reactions were used as typical examples of a nonlinear system far from equilibrium in connection with biological evolution. The virtual absence of gravity in the present work was given from the free-fall facility of Japan Microgravity Center (JAMIC) in Hokkaido. The reaction solution of BZ reaction was composed of bromate in sulfuric acid, 1,4-cyclohexanedione and ferroin to visualize the time development of patterns of chemical oscillations in the reaction-diffusion system. It is a bubble-free constitution in the aging of the reaction. Therefore, the setup constructed to collect image data via CCD cameras was simplified. The operation sequences of necessary devices were comprised of simple solid state relays which were started by a command from the operation room of JAMIC. The propagation profile of chemical patterns under microgravity of 10-5 g was collected as image data for 9.8 s, and processed by a software of STM-STS2. In the aqueous solutions, propagation velocity of chemical patterns under microgravity was decreased to 80.9 % of that under normal gravity, owing to suppression of convection. On the other hand, in gel matrix, gravity did not influence the propagation velocity.

  14. EFFECTS STUDY OF NIGELLA SATIVA, ITS OIL AND THEIR COMBINATION WITH VITAMIN E ON OXIDATIVE STRESS IN RATS

    Directory of Open Access Journals (Sweden)

    Amr A. Rezq

    2014-01-01

    Full Text Available Antioxidants or free radical scavengers are very important in protecting the living cells against any damage induced by free radicals. The effects of Nigella Sativa Extract (NSE, Nigella Sativa Oil (NSO and Vitamin E (Vit. E and the combination of NSE or NSO with Vit. E on potassium bromate (KBrO3-induced oxidative stress in male rats were investigated. Forty nine Sprague Dawley male rats were weighingv 185±5 g and 10-12 weeks old were used to achieve the present study. According to the results, oral administration of NSE or NSO alone and in combination with vitamin E exhibited weight gain and feed efficiency ratio and lowered the elevated serum levels of total cholesterol, triglycerides, AST, ALT, urea nitrogen, uric acid and creatinine. Further, they lowered malondialdehyde and increased the reduction in glutathione content and activities of antioxidant enzymes (GPx, SOD and CAT in liver tissues. Collectively, these results indicate that dietary intake of NSE or NSO alone and in combination with Vitamin E could be a potential therapeutic in the treatment of related diseases with oxidative stress."

  15. Evaluation of the sensitivity of three sublethal cytotoxicity assays in human HepG2 cell line using water contaminants

    International Nuclear Information System (INIS)

    The in vitro toxicological index IC50 (the millimolar concentration of compound which inhibits response assay by 50% compared to the solvent control) of 11 water contaminants (acrylamide, atrazine, B[a]P, BPA, 2,4-DAT, 17-αEE, H2O2, 4-OP, sodium bromate, sodium chlorate, sodium nitrate) was evaluated on the human hepatoma (HepG2) cells using three short-term bioassays related to their morbidity status [radiometric RNA synthesis assay (RNA), luminometric ATP assay (ATP), fluorometric Alamar blue assay (AB)]. Among all substances, we were not able to determine atrazine IC50 value whatever the test used. Furthermore, B[a]P was not cytotoxic in the ATP and AB assays. Statistical analysis revealed a correlation between the IC50 values obtained in the three assays. Except with 4-OP, RNA assay was always inhibited at lower concentrations than those required in the other assays, suggesting that this assay is a very sensitive indicator of the presence of toxic compounds. ATP and AB assays responded to a similar pattern. Due to its higher sensitivity and its reliability, RNA synthesis assay using HepG2 cell line provides the most suitable tool for the screening of water contaminants

  16. Simple and sensitive synchronous- fluorescence method for the determination of trace bisphenol S based on its inhibitory effect on the fluorescence quenching reaction of rhodamine B.

    Science.gov (United States)

    Cao, Gui-ping; Chen, Ting; Zhuang, Ya-feng

    2013-07-01

    An inhibitory kinetic fluorimetric method is reported for the determination of trace bisphenol S (BPS). The proposed method is based on the inhibitory effect of BPS on the fluorescence quenching of rhodamine B (RhB) caused by potassium bromate in a dilute phosphoric acid medium. Under the optimal conditions of the experiment, the detection limit for BPS was 0.021 mg/L, and the linear range of determination was from 0.035 mg/L to 0.750 mg/L. The relative standard deviations of 11 measurements for 0.20 mg/L and 0.40 mg/L BPS solutions were 2.74 % and 1.87 %, respectively. The method was successfully applied to the determination of bisphenol S derived from commercially available plastic film samples in hot water. A possible reaction mechanism of the inhibitory effect of BPS on the fluorescence quenching of RhB was proposed.

  17. Photocatalytic degradation of a widely used insecticide Thiamethoxam in aqueous suspension of TiO{sub 2}: Adsorption, kinetics, product analysis and toxicity assessment

    Energy Technology Data Exchange (ETDEWEB)

    Mir, Niyaz A.; Khan, A. [Department of Chemistry, Aligarh Muslim University, Aligarh-202002, UP (India); Muneer, M., E-mail: readermuneer@gmail.com [Department of Chemistry, Aligarh Muslim University, Aligarh-202002, UP (India); Vijayalakhsmi, S. [SAIF, CRNTS, IIT Bombay, Powai, 400076, Mumbai (India)

    2013-08-01

    This paper deals with the study of photocatalyzed degradation of an insecticide, Thiamethoxam in aqueous suspension of TiO{sub 2}. The adsorption of Thiamethoxam on TiO{sub 2} surface under dark conditions was also investigated in order to find out equilibrium adsorption constant. The degradation kinetics was studied using spectrophotometric method under various conditions such as substrate concentration, type of catalyst, catalyst dosage, pH, and in the presence of electron acceptors such as hydrogen peroxide, potassium bromate, and ammonium persulphate under continuous purging of atmospheric oxygen, and the degradation rates were found to be strongly influenced by these parameters. The results manifested that the photocatalysis of Thiamethoxam follows pseudo-first-order kinetics. The toxicity assessments of the irradiated samples were carried out using human erythrocytes as a model system under in vitro conditions. GC–MS study showed the formation of several intermediate products which were characterised based on their molecular mass and mass fragmentation pattern. A probable mechanism for the formation of various products formed during the photocatalytic process of Thiamethoxam was also proposed. Highlights: • TiO{sub 2} P25 is a more efficient photocatalyst than UV100 and PC500 for degradation of Thiamethoxam. • Low H{sub 2}O{sub 2} dosages enhance degradation whereas overdose retards it. • Toxicity of Thiamethoxam decreases with the increase in irradiation time. • Eight intermediate products have been identified using GC–MS analysis technique.

  18. New inorganic (an)ion exchangers based on Mg–Al hydrous oxides: (Alkoxide-free) sol–gel synthesis and characterisation

    KAUST Repository

    Chubar, Natalia

    2011-05-01

    New inorganic ion exchangers based on double Mg-Al hydrous oxides were generated via the new non-traditional sol-gel synthesis method which avoids using metal alkoxides as raw materials. Surface chemical and adsorptive properties of the final products were controlled by several ways of hydrogels and xerogels treatments which produced the materials of the layered structure, mixed hydrous oxides or amorphous adsorbents. The final adsorptive materials obtained via thermal treatment of xerogels were the layered mesoporous materials with carbonate in the interlayer space, surface abundance with hydroxylic groups and maximum adsorptive capacity to arsenate. Higher affinity of Mg-Al hydrous oxides towards H2AsO4- is confirmed by steep adsorption isotherms having plateau (removal capacity) at 220. mg[As]. gdw-1 for the best sample at pH = 7, fast adsorption kinetics and little pH effect. Adsorption of arsenite, fluoride, bromate, bromide, selenate, borate by Mg-Al hydrous oxides was few times high either competitive (depending on the anion) as compare with the conventional inorganic ion exchange adsorbents. © 2011 Elsevier Inc.

  19. Risk analysis of drinking water microbial contamination versus disinfection by-products (DBPs)

    International Nuclear Information System (INIS)

    Managing the provision of safe drinking water has a renewed focus in light of the new World Health Organization (WHO) water safety plans. Risk analysis is a necessary component to assist in selecting priority hazards and identifying hazardous scenarios, be they qualitative to quantitative assessments. For any approach, acute diarrhoeal pathogens are often the higher risk issue for municipal water supplies, no matter how health burden is assessed. Furthermore, potential sequellae (myocarditis, diabetes, reactive arthritis and cancers) only further increase the potential health burden of pathogens; despite the enormous uncertainties in determining pathogen exposures and chemical dose-responses within respective microbial and chemical analyses. These interpretations are currently being improved by Bayesian and bootstrapping approaches to estimate parameters for stochastic assessments. A case example, covering the health benefits of ozonation for Cryptosporidium inactivation versus potential cancers from bromate exposures, illustrated the higher risks from a pathogen than one of the most likely disinfection by-products (DBPs). Such analyses help justify the industries long-held view of the benefits of multiple barriers to hazards and that microbial contamination of water supplies pose a clear public health risk when treatment is inadequate. Therefore, efforts to reduce potential health risks from DBP must not compromise pathogen control, despite socio-political issues

  20. Methyl chloride and methyl bromide emissions from baking: an unrecognized anthropogenic source.

    Science.gov (United States)

    Thornton, Brett F; Horst, Axel; Carrizo, Daniel; Holmstrand, Henry

    2016-05-01

    Methyl chloride and methyl bromide (CH3Cl and CH3Br) are the largest natural sources of chlorine and bromine, respectively, to the stratosphere, where they contribute to ozone depletion. We report the anthropogenic production of CH3Cl and CH3Br during breadbaking, and suggest this production is an abiotic process involving the methyl ester functional groups in pectin and lignin structural polymers of plant cells. Wide variations in baking styles allow only rough estimates of this flux of methyl halides on a global basis. A simple model suggests that CH3Br emissions from breadbaking likely peaked circa 1990 at approximately 200tonnes per year (about 0.3% of industrial production), prior to restrictions on the dough conditioner potassium bromate. In contrast, CH3Cl emissions from breadbaking may be of similar magnitude as acknowledged present-day CH3Cl industrial emissions. Because the mechanisms involve functional groups and compounds widely found in plant materials, this type of methyl halide production may occur in other cooking techniques as well. PMID:26878644

  1. A new kinetic spectrophotometric method for the determination of major metabolite of heroin in biological samples

    Institute of Scientific and Technical Information of China (English)

    M. Reza Shishehbore; Ali Sheibani; Ehsan Mirparizi

    2012-01-01

    This study describes a simple,rapid and selective catalytic kinetic spectrophotometric method for the determination of 6-monoacetylmorphine (6-MAM) as major metabolite of heroin in biological samples.The method is based upon the catalytic effect of 6-MAM on the oxidation of Janus Green by bromate in acid media.The reaction was followed spectrophotometrically by measuring the decrease in absorbance of Janus Green at 618 nm.The dependence of sensitivity on the reaction variables was studied.Under optimum conditions,two linear calibration curves over the range 0.1-1.0 μg mL-1 and 1.0-34.0 μg mL-1 of 6-MAM were obtained.The detection limit was 1.2 × 10-2 μg mL-1 of 6-MAM.The relative standard deviations for six replicate determinations of 0.8 and 5.0 μg mL 1 of 6-MAM were 1.4 and 1.1% respectively.The effect of various species commonly associated with heroin in real samples was also investigated.The proposed method was successfully applied in human urine and serum samples with satisfactory results.

  2. Zeolitic polyoxometalate-based metal-organic frameworks (Z-POMOFs): computational evaluation of hypothetical polymorphs and the successful targeted synthesis of the redox-active Z-POMOF1.

    Science.gov (United States)

    Rodriguez-Albelo, L Marleny; Ruiz-Salvador, A Rabdel; Sampieri, Alvaro; Lewis, Dewi W; Gómez, Ariel; Nohra, Brigitte; Mialane, Pierre; Marrot, Jérôme; Sécheresse, Francis; Mellot-Draznieks, Caroline; Ngo Biboum, Rosa; Keita, Bineta; Nadjo, Louis; Dolbecq, Anne

    2009-11-11

    The targeted design and simulation of a new family of zeolitic metal-organic frameworks (MOFs) based on benzenedicarboxylate (BDC) as the ligand and epsilon-type Keggin polyoxometalates (POMs) as building units, named here Z-POMOFs, have been performed. A key feature is the use of the analogy between the connectivity of silicon in dense minerals and zeolites with that of the epsilon-type Keggin POMs capped with Zn(II) ions. Handling the epsilon-Keggin as a building block, a selection of 21 zeotype structures, together with a series of dense minerals were constructed and their relative stabilities computed. Among these Z-POMOFs, the cristobalite-like structure was predicted to be the most stable structure. This prediction has been experimentally validated by the targeted synthesis of the first experimental Z-POMOF structure, which was strikingly found to possess the cristobalite topology, with three interpenetrated networks. Crystals of [NBu(4)](3)[PMo(V)(8)Mo(VI)(4)O(36)(OH)(4)Zn(4)(BDC)(2)].2H(2)O (Z-POMOF1) have been isolated under hydrothermal conditions from the reduction of ammonium heptamolybdate in the presence of phosphorous acid and Zn(II) ions. Tetrabutylammonium cations play the role of counterions and space-filling agents in this tridimensional interpenetrated framework. Moreover, the electrochemistry of the epsilon-Keggin POM is maintained and can be exploited in the insoluble Z-POMOF1 framework, as demonstrated by the electrocatalytic reduction of bromate.

  3. An on-line spectrophotometric determination of trace amounts of thiourea in tap water, orange juice, and orange peel samples using multi-channel flow injection analysis.

    Science.gov (United States)

    Arab Chamjangali, M; Goudarzi, N; Ghochani Moghadam, A; Amin, A H

    2015-01-01

    In this work, a flow injection analysis (FIA) method was introduced for the determination of trace amounts of thiourea in tap water. This method is based upon the inhibition effect of thiourea on the reaction between meta-cresol purple (MCP) and potassium bromate catalyzed by bromide ions in a sulfuric acid medium. In the presence of thiourea, an induction period appears in the reaction system, and as a result, the absorbance of MCP increases at 525 nm in the FIA manifold. The chemical and FIA variables are studied and optimized using the univariate and Simplex optimization methods. Under the optimum conditions, thiourea can be determined in the range of 0.100-13.0 μg mL(-1). The limit of detection (3σ) for thiourea was found to be 0.0310 μg mL(-1). The relative standard deviations (RSDs) for six replicate determinations of 0.500, 5.00, and 12.0 μg mL(-1) of thiourea were 4.0%, 1.8%, and 1.2%, respectively. The proposed method was also applied for the determination of thiourea in orange juice and orange peel samples with recoveries in the range of 98.0-101%. The analytical speed of the method was calculated to be about 120 sample per hour.

  4. FIA versatile system for spectrophotometric determinations of vanadium and molybdenum exploring the catalytic activities of V(V) and Mo(VI)

    International Nuclear Information System (INIS)

    A versatile system for chemical analysis by flow injection analysis was developed and applied for catalytic spectrophotometric determination of vanadium or molybdenum in metallic alloys. The selected methods were based upon indicator reactions chromotropic (CS)-bromate acid or hydrogen iodide-peroxide, respectively. Initially, a model system was proposed, in which common parameters for methods were studied. This included a re-sampling process in which high degrees of samples dilution were obtained. Other parameters such as concentrations and reagents addition order, reaction medium Ph, temperature and ionic power, as well as procedures for sample solubilization, were studied relating to each method. A mini-column with cationic exchanger resin (Dowex 50W-X8, 50-100 mesh, H+ form) was used. The system for vanadium determination processes 120 samples by hour, consuming 2,0 mg CS and 10 mg K Br O3by determination. Concerning the method for molybdenum, the reagents consumption was 2,0 mg KI and 1,0 μL of solution 30% H2O2 by determination, since the analytic velocity was the same, in relation to vanadium

  5. 流动注射动力学光度法测定环境雌激素双酚A%Flow injection spectrophotometric determination of environmental estrogen bisphenol A

    Institute of Scientific and Technical Information of China (English)

    王广军; 高霞; 樊静; 刘国光

    2011-01-01

    A flow injection spectrophotometric method is developed for the measurement of environmental estrogen bisphenol A. The method is based on the inhibitory effect of bisphenol A on the oxidation reaction of gallocyanin by potassium bromate in hydrochloric acid medium. The detection limit for bisphenol A is 0. 027 μg/mL, and the linear range of the determination for bisphenol A is 0. 10 ~ 1.1 μg/mL. This method has been applied successfully to the determination of bisphenol A in nasal aspirator, feeding bottle, beverage bottle,false teeth, topsoil and surface water.%在HCl介质中,增敏剂十六烷基三甲基溴化铵存在下双酚A对KBrO3氧化棓花青褪色反应有明显的抑制作用,据此建立了测定痕量双酚A的流动注射动力学光度分析法.方法的线性范围为0.10~1.10μg/mL,检出限0.027μg/mL,回收率在96%~103%之间.该方法已用于吸鼻器、奶瓶、饮料瓶、假牙、表层土和地表水中双酚A含量的测定.

  6. Application of biofiltration system on AOC removal: Column and field studies

    Energy Technology Data Exchange (ETDEWEB)

    Chien, C.C.; Kao, C.M.; Chen, C.W.; Dong, C.D.; Wu, C.Y. [National Sun Yat Sen University, Kaohsiung (Taiwan). Inst. for Environmental Engineering

    2008-04-15

    The Cheng-Ching Lake Water Treatment Plant (CCLWTP) is the main supplier of domestic water for the Greater Kaohsiung area, the second largest metropolis in Taiwan. Biological activated carbon (BAC) filtration is one of the major treatment processes in CCLWTP. The objectives of this study were to evaluate the effectiveness of BAC filtration on water treatment in the studied advanced water treatment plant and its capability on pollutants (e.g., AOC (assimilable organic carbon) removal. In this study, water samples from each treatment process of CCLWTP were collected and analyzed periodically to assess the variations in concentrations of AOC and other water quality indicators after each treatment unit. Moreover, the efficiency of biofiltration process using granular activated carbon (GAC) and anthracite as the fillers was also evaluated through a column experiment. Results show that the removal efficiencies for AOC, bromide, bromate, and iron are 86% 100%, 17%, and 30% after the BAC filter bed, respectively. This indicates that BAC filtration plays an important role in pollutant removal. Results of column study show that the AOC removal efficiencies in the GAC and anthracite columns are 60% and 17%, respectively. Microbial colonization on GAC and anthracite were detected via the observation of scanning electron microscopic images. The observed microorganisms included bacteria (rods, cocci, and filamentous bacteria), fungi, and protozoa.

  7. New Inorganic-organic Hybrid Compound Containing One Dimensional Keggin Polyoxometalate[SiW11O39Co]6- Chains:Preparation,Characterization and Application in Chemically Bulk-modified Electrode

    Institute of Scientific and Technical Information of China (English)

    WANG Xiu-li; LIN Hong-yan; LIU Guo-cheng; CHEN Bao-kuan; BI Yan-feng

    2008-01-01

    A new inorganic-organic hybrid compound based on polyoxometalate and organic ligand formulated as (H2bpp)3[SiW11O39Co]~2H2O(1)[bpp=1,3-bis(4-pyridyl)propane]was hydrothermally synthesized and structurally characterized by elemental analysis,single-crystal X-ray diffraction,IR,TG,and cyclic voltammetry.Single-crystal X-ray diffraction analysis reveals that compound 1 consists of interesting cobalt-monosubstituted POMs one dimensional chain together with protonated bpp ligands.Additionally,the polyoxoanions combined with the discrete organic substrates by hydrogen bond interactions to afford a supramolecular 3D network structure.The hybrid compound 1 was used as a bulk modifier to fabricate a three-dimensional chemically modified carbon paste electrode(1-CPE)by direct mixing.The electrochemical behavior and electrocatalysis of 1-CPE were studied in detail.The results indicate that 1-CPE has good electrocatalytic activities toward the reduction of nitrite or bromate in 1mol/L H2SO4 aqueous solution.1-CPE shows remarkable stability that can be ascribed to the insolubility of compound 1 and the supramolecular interactions existed between 1D POM anion chains and organic ligand bpp,which is very important for practical applications in electrode modification.

  8. Heterogeneous photocatalysed degradation of two selected pesticide derivatives, triclopyr and daminozid in aqueous suspensions of titanium dioxide.

    Science.gov (United States)

    Qamar, M; Muneer, M; Bahnemann, D

    2006-07-01

    Heterogeneous photocatalysed degradation of two selected pesticide derivatives, triclopyr (1) and daminozid (2), has been investigated in aqueous suspensions of titanium dioxide by monitoring the change in substrate concentration employing the UV Spectroscopic analysis technique and depletion of Total Organic Carbon (TOC) content as a function of irradiation time. The degradation kinetics were studied under different conditions such as reaction pH, substrate and catalyst concentration, different types of TiO2 and in the presence of electron acceptors such as hydrogen peroxide (H2O2), potassium bromate (KBrO3) and ammonium persulphate (NH4)2S2O8 in addition to molecular oxygen. The degradation rates were found to be strongly influenced by all the above parameters. The photocatalyst Degussa P25 was found to be more efficient as compared with other photocatalysts. The pesticide derivative triclopyr (1) was found to degrade faster as compared to daminozid (2). An attempt was also made to identify the intermediate products formed during the photooxidation process using GC/MS analysis. Probable pathways for the formation of products have been proposed. PMID:16359776

  9. Laser-induced removal of a dye C.I. Acid Red 87 using n-type WO3 semiconductor catalyst

    International Nuclear Information System (INIS)

    Water contamination by organic substances such as dyes is of great concern worldwide due to their utilization in many industrial processes and environmental concerns. To cater the needs for waste water treatment polluted with organic dyes, laser-induced photocatalytic process was investigated for removal of a dye derivative namely Acid Red 87 using n-type WO3 semiconductor catalyst. The degradation was investigated in aqueous suspensions of tungsten oxide under different experimental conditions using laser instead of conventional UV lamp as an irradiation source. The degradation process was monitored by measuring the change in dye concentration as a function of laser irradiation time by employing UV spectroscopic analysis. The degradation of dye was studied by varying different parameters such as laser energy, reaction pH, substrate concentration, catalyst concentration, and in the presence of electron acceptors such as hydrogen peroxide (H2O2), and potassium bromate (KBrO3). The degradation rates were found to be strongly dependent on all the above-mentioned parameters. Our experimental results revealed that the dye degradation process was very fast (within few minutes) under laser irradiation as compared to conventional setups using broad spectral lamps (hours or days) and this laser-induced photocatalytic degradation method could be an effective means to eliminate the pollutants present in liquid phase. The experience gained through this study could be beneficial for treatment of waste water contaminated with organic dyes and other organic pollutants.

  10. Integration of vanadium-mixed addenda Dawson heteropolytungstate within poly(3,4-ethylenedioxythiophene) and poly(2,2'-bithiophene) films by electrodeposition from the nonionic micellar aqueous medium

    Energy Technology Data Exchange (ETDEWEB)

    Goral, Monika [Department of Chemistry, University of Warsaw, Pasteura 1, 02-093 Warsaw (Poland); Jouini, Mohamed, E-mail: jouini@univ-paris-diderot.f [Laboratory Interfaces, Traitements, Organisation et DYnamique des Systemes (ITODYS) UMR 7086, Universite Paris Diderot Paris 7 Batiment Lavoisier, 15 Rue Jean Antoine de Baif, 75205 Paris Cedex 13 (France); Perruchot, Christian [Laboratory Interfaces, Traitements, Organisation et DYnamique des Systemes (ITODYS) UMR 7086, Universite Paris Diderot Paris 7 Batiment Lavoisier, 15 Rue Jean Antoine de Baif, 75205 Paris Cedex 13 (France); Miecznikowski, Krzysztof; Rutkowska, Iwona A. [Department of Chemistry, University of Warsaw, Pasteura 1, 02-093 Warsaw (Poland); Kulesza, Pawel J., E-mail: pkulesza@chem.uw.edu.p [Department of Chemistry, University of Warsaw, Pasteura 1, 02-093 Warsaw (Poland)

    2011-04-01

    A comparative study describing immobilization of the Dawson type mixed addenda heteropolyanion, [P{sub 2}W{sub 17}VO{sub 62}]{sup 8-} into conducting polymer films of poly(3,4-ethylenedioxythiophene), PEDOT, and poly(2,2'-bithiophene), PBT, is reported. Electrosynthesis of these hybrid films was performed using a micellar aqueous solution of the nonionic surfactant, polyethylene glycol tert-octylphenyl ether (Triton X-100). Deposited composite films were characterised electrochemically and, on the whole, they exhibited fast electron transfer (ET) properties and relatively high stability towards continuous potential cycling in acidic media. In particular, PEDOT composite showed relatively faster ET properties in comparison to PBT composite. Their permeability was investigated in the presence of cationic and anionic redox probes. Our results implied good mediating capabilities of the [P{sub 2}W{sub 17}V{sup 4+}O{sub 62}]{sup 8-} anion (within the [P{sub 2}W{sub 17}V{sup 4+}O{sub 62}]{sup 8-}-PEDOT hybrid film) towards the iron (III) reduction. The specific electrocatalytic (reductive) capabilities of hybrid films were also studied by probing the reduction of bromate. The films were further characterised by X-ray photoelectron spectroscopy to establish their interfacial elemental composition. Moreover, their surface morphology was imaged by atomic force microscopy and scanning electron microscopy. Results have shown that physicochemical properties of the investigated hybrid films were affected by polymer hydrophobicity.

  11. The use of ion chromatography in environmental and process control in the nuclear industry. Vol. 4

    International Nuclear Information System (INIS)

    Ion chromatography has become the method choice for determining sub ppb for inorganic anions and cations, such as chloride, sulfide, fluoride, sodium, potassium, and ammonium, in aqueous matrices. Steam generators in pressurized water reactors nuclear power plants occasionally experience tubing degradation by a variety of corrosion related mechanisms which depends on water chemistry. Ion chromatography is also used in other environmental applications such as air pollution, industrial hygiene, drinking water quality, and industrial waste treatment. In this paper, several methods of separation and detection are present and also a number of examples of samples for various types of water are shown. The examples will include sub ppb amounts of chloride, sulfate, sodium, potassium, and ammonium in high purity turbine steam. Testing of chlorinated drinking water for inorganic anions including chlorite, chloride chlorate nitrite, nitrate as other organic anions using chemically suppressed conductivity. The role of chemical suppression is discussed. The analysis of ppb levels of transition moles in high purity water using ion chromatography with post column derivatization and UV detection are reviewed. Testing of disinfected drinking water with ozone for bromate, the detection of cyanide in waste after acid digestion, and the detection of highly toxic hexavalent in the presence of trivalent chromium is discussed. A fast method for the analysis of rain water for anions and cations is described. The presentation will also show new method (chelation ion chromatography) which enables ppb levels of heavy metals to be determined as pollutants in difficult environmental matrices such seawater, and oyster tissue. 4 figs

  12. Determination of trace platinum by supramolecular catalytic kinetic spectrofluorimetry of {beta}-cyclodextrin-platinum-KBrO{sub 3}-salicylaldehyde furfuralhydrazone

    Energy Technology Data Exchange (ETDEWEB)

    Tang, Bo; Zhang, Ning; Chen, Zhen-Zhen; Kong, Qing-Cheng [Shandong Normal University, College of Chemistry, Chemical Engineering and Materials Science, Jinan (China)

    2006-02-01

    A supramolecular catalytic kinetic spectrofluorimetric method was developed for the determination of platinum(IV) and the possible mechanism of catalytic reaction was discussed. The method was based on the fluorescence-enhancing reaction of salicylaldehyde furfuralhydrazone (SAFH) with potassium bromate, which was catalysed by platinum(IV) in a water-ethanol medium. {beta}-Cyclodextrin ({beta}-CD) obviously sensitized the determination at pH 5.20 and 25 C. Under optimum conditions, the {beta}-CD-platinum-KBrO{sub 3}-SAFH supramolecular kinetic catalytic reaction system had excitation and emission maxima at 372 and 461 nm, respectively. The linear range of this method was 0.60-180 ng ml{sup -1} with a relative standard deviation of 1.2%, and the detection limit was 0.18 ng ml{sup -1}. Investigation of the mechanism and the effects of interferences is presented. The proposed method was applied successfully to determine trace platinum(IV) in the chemotherapeutic drug cisplatin and serum from patients with satisfactory results. (orig.)

  13. Controlling various contaminants in wastewater effluent through membranes and engineered wetland

    Institute of Scientific and Technical Information of China (English)

    Sarper SARP; Sungyun LEE; Noeon PARK; Nguyen Thi HANH; Jaeweon CHO

    2009-01-01

    For effective wastewater reclamation and water recovery, the treatment of natural and effluent organic matters (NOM and EfOM), toxic anions, and micropollutants was considered in this work. Two different NOM (humic acid of the Suwannee River, and NOM of US and Youngsan River, Korea), and one EfOM from the Damyang wastewater treatment plant, Korea, were selected for investigating the removal efficiencies of tight nanofiltration (NF) and ultrafiltration (UF) membranes with different properties. Nitrate, bromate, and perchlorate were selected as target toxic anions due to their well known high toxicities. Tri-(2-chloroethyl)-phosphate (TCEP),oxybenzone, and caffeine, due to their different Kow and pKa values, were selected as target micropollutants. As expected, the NF membranes provided high removal efficiencies in terms of all the tested contaminants, and the UF membrane provided fairly high removal efficien-cies for anions (except for nitrate) and the relatively hydrophobic micropollutant, oxybenzon. Through the wetlands, nitrate was successfully removed. Therefore, a fair process of combining membranes with an engineered wetland could be proposed for sustainable wastewater reclamation and optimum control of contaminats.

  14. Belousov-Zhabotinsky autonomic hydrogel composites: Regulating waves via asymmetry

    Science.gov (United States)

    Buskohl, Philip R.; Vaia, Richard A.

    2016-01-01

    Belousov-Zhabotinsky (BZ) autonomic hydrogel composites contain active nodes of immobilized catalyst (Ru) encased within a nonactive matrix. Designing functional hierarchies of chemical and mechanical communication between these nodes enables applications ranging from encryption, sensors, and mechanochemical actuators to artificial skin. However, robust design rules and verification of computational models are challenged by insufficient understanding of the relative importance of local (molecular) heterogeneities, active node shape, and embedment geometry on transient and steady-state behavior. We demonstrate the predominance of asymmetric embedment and node shape in low-strain, BZ-gelatin composites and correlate behavior with gradients in BZ reactants. Asymmetric embedment of square and rectangular nodes results in directional steady-state waves that initiate at the embedded edge and propagate toward the free edge. In contrast, symmetric embedment does not produce preferential wave propagation because of a lack of diffusion gradient across the catalyzed region. The initiation at the embedded edge is correlated with bromide absorption by the inactive matrix, which locally elevates the bromate concentration required for catalyst oxidation. The competition between embedment asymmetry and node geometry was used to demonstrate a repeatable switch in wave direction that functions as a signal delay. Furthermore, signal propagation in or out of the composite was demonstrated via embedment asymmetry and relative dimensions of a T-shaped active network node. Overall, structural asymmetry provides a robust approach to controlling initiation and orientation of chemical-mechanical communication within composite BZ gels. PMID:27679818

  15. A nanoliter-scale open chemical reactor.

    Science.gov (United States)

    Galas, Jean-Christophe; Haghiri-Gosnet, Anne-Marie; Estévez-Torres, André

    2013-02-01

    An open chemical reactor is a container that exchanges matter with the exterior. Well-mixed open chemical reactors, called continuous stirred tank reactors (CSTR), have been instrumental for investigating the dynamics of out-of-equilibrium chemical processes, such as oscillations, bistability, and chaos. Here, we introduce a microfluidic CSTR, called μCSTR, that reduces reagent consumption by six orders of magnitude. It consists of an annular reactor with four inlets and one outlet fabricated in PDMS using multi-layer soft lithography. A monolithic peristaltic pump feeds fresh reagents into the reactor through the inlets. After each injection the content of the reactor is continuously mixed with a second peristaltic pump. The efficiency of the μCSTR is experimentally characterized using a bromate, sulfite, ferrocyanide pH oscillator. Simulations accounting for the digital injection process are in agreement with experimental results. The low consumption of the μCSTR will be advantageous for investigating out-of-equilibrium dynamics of chemical processes involving biomolecules. These studies have been scarce so far because a miniaturized version of a CSTR was not available.

  16. Solar photocatalytic H{sub 2} production from water using a dual bed photosystem

    Energy Technology Data Exchange (ETDEWEB)

    Linkous, C.A. [Florida Solar Energy Center, Cocoa, FL (United States)

    1996-10-01

    The authors are developing a dual stage, direct photoconversion scheme for water splitting. The overall system consists of an aqueous solution circulated through two modules, or beds, each of which contains a photochemically active surface layer below the solution. The idea is to divide the energy requirement for water decomposition between the two photosystems, so that more abundant, lower energy photons in the solar spectrum can be utilized, and that the H{sub 2} and O{sub 2} products can be evolved separately from each other. Catalyst-modified semiconductor powders, immobilized within a polymer binder are currently being employed as the photoactive layers. TiO{sub 2} and platinized-InP have been employed for the O{sub 2} and H{sub 2} evolution tasks, respectively. A major effort over the last year was identification of a suitable redox mediator that is responsible for transferring electron equivalents from one unit to the other. After testing more than a dozen candidates, spanning a wide range of electropotentials, under a variety of conditions, it was found that the bromide/bromate (Br{sup {minus}}/BrO{sub 3}{sup {minus}}) and iodide/iodate (I{sup {minus}}/IO{sub 3}{sup {minus}}) redox systems could function in both modules, necessary for closed cycle operation.

  17. Study on Pentosan from Corn Fiber by Alkaline Peroxide Extraction and Oxidative Cross-linking Property of Pentosan%碱性过氧化氢法提取玉米皮戊聚糖及其氧化交联性质的研究

    Institute of Scientific and Technical Information of China (English)

    王文侠; 张晓静; 宋春丽; 李建强

    2012-01-01

    Extracting pentosan was studied by alkaline peroxide treatment of the corn fiber. Extracted pentosan with ammomium persulfae, potassium bromate and hydrogen peroxide/peroxidase was studied. The effects of the concentration of hydrogen peroxide, pH, ratio of solid to liquid, temperature, extraction time and temperature on the yield of pentosan were studied respectively. Based on the results, other four key factors except ratio of solid to liquid were optimized through response surface methodology with four factors and three levels based on the principle of Box-Behnken design. The results showed that the optimum extraction conditions were 85 ℃, hydrogen peroxide concentration 2.14%, pH 11.65, 2.23 h, ratio of substrate and water 1:25(m/V). Under this optimal conditions, the yield of pentosan was highly reach to 47.18%. Extracted pentosan with ammomium persulfae, potassium bromate and hydrogen peroxide/peroxidase gave a slow increase in viscosity and when pentosan concentration was 1%(m/V), optimum concentration of three oxidant was 0.75%, 0.17%, 10 U/g pentosan respectively.%以玉米皮为原料,对碱性过氧化氢提取玉米皮中的戊聚糖提取条件以及戊聚糖的氧化交联性质进行研究.在考察H2O2溶液的体积分数、H2O2的pH值、固液比、提取时间、提取温度5个因素对戊聚糖得率影响的基础上,根据Box-Benhnken中心组合试验设计原理,采用四因素三水平响应面分析法,确定戊聚糖提取的最优条件是:固液比为1∶25(m/V),H2O2溶液体积分数2.14%,pH 11.65,提取温度85℃,提取时间2.23 h,此条件下戊聚糖得率达到47.18%.戊聚糖的氧化交联性与氧化剂的用量有关,用量过多或过少均会使氧化交联程度减弱.在糖质量分数为1%时,(NH4)2S2O8、KBrO3及过氧化氢与过氧化物酶(H2O2/POX)3个体系中氧化剂的最适用量分别为0.75%,0.17%,10U/g戊聚糖,此时有利于戊聚糖氧化凝胶的形成.

  18. Remedial Process Optimization and Green In-Situ Ozone Sparging for Treatment of Groundwater Impacted with Petroleum Hydrocarbons

    Science.gov (United States)

    Leu, J.

    2012-12-01

    A former natural gas processing station is impacted with TPH and BTEX in groundwater. Air sparging and soil vapor extraction (AS/AVE) remediation systems had previously been operated at the site. Currently, a groundwater extraction and treatment system is operated to remove the chemicals of concern (COC) and contain the groundwater plume from migrating offsite. A remedial process optimization (RPO) was conducted to evaluate the effectiveness of historic and current remedial activities and recommend an approach to optimize the remedial activities. The RPO concluded that both the AS/SVE system and the groundwater extraction system have reached the practical limits of COC mass removal and COC concentration reduction. The RPO recommended an in-situ chemical oxidation (ISCO) study to evaluate the best ISCO oxidant and approach. An ISCO bench test was conducted to evaluate COC removal efficiency and secondary impacts to recommend an application dosage. Ozone was selected among four oxidants based on implementability, effectiveness, safety, and media impacts. The bench test concluded that ozone demand was 8 to 12 mg ozone/mg TPH and secondary groundwater by-products of ISCO include hexavalent chromium and bromate. The pH also increased moderately during ozone sparging and the TDS increased by approximately 20% after 48 hours of ozone treatment. Prior to the ISCO pilot study, a capture zone analysis (CZA) was conducted to ensure containment of the injected oxidant within the existing groundwater extraction system. The CZA was conducted through a groundwater flow modeling using MODFLOW. The model indicated that 85%, 90%, and 95% of an injected oxidant could be captured when a well pair is injecting and extracting at 2, 5, and 10 gallons per minute, respectively. An ISCO pilot test using ozone was conducted to evaluate operation parameters for ozone delivery. The ozone sparging system consisted of an ozone generator capable of delivering 6 lbs/day ozone through two ozone

  19. Trade-offs in disinfection byproduct formation associated with precursor preoxidation for control of N-nitrosodimethylamine formation.

    Science.gov (United States)

    Shah, Amisha D; Krasner, Stuart W; Lee, Chih Fen Tiffany; von Gunten, Urs; Mitch, William A

    2012-05-01

    Chloramines in drinking water may form N-nitrosodimethylamine (NDMA). Various primary disinfectants can deactivate NDMA precursors prior to chloramination. However, they promote the formation of other byproducts. This study compared the reduction in NDMA formation due to chlorine, ozone, chlorine dioxide, and UV over oxidant exposures relevant to Giardia control coupled with postchloramination under conditions relevant to drinking water practice. Ten waters impacted by treated wastewater, poly(diallyldimethylammonium chloride) (polyDADMAC) polymer, or anion exchange resin were examined. Ozone reduced NDMA formation by 50% at exposures as low as 0.4 mg×min/L. A similar reduction in NDMA formation by chlorination required ∼60 mg×min/L exposure. However, for some waters, chlorination actually increased NDMA formation at lower exposures. Chlorine dioxide typically had limited efficacy regarding NDMA precursor destruction; moreover, it increased NDMA formation in some cases. UV decreased NDMA formation by ∼30% at fluences >500 mJ/cm(2), levels relevant to advanced oxidation. For the selected pretreatment oxidant exposures, concentrations of regulated trihalomethanes, haloacetic acids, bromate, and chlorite typically remained below current regulatory levels. Chloropicrin and trichloroacetaldehyde formation were increased by preozonation or medium pressure UV followed by postchloramination. Among preoxidants, ozone achieved the greatest reduction in NDMA formation at the lowest oxidant exposure associated with each disinfectant. Accordingly, preozonation may inhibit NDMA formation with minimal risk of promotion of other byproducts. Bromide >500 μg/L generally increased NDMA formation during chloramination. Higher temperatures increased NDMA precursor destruction by preoxidants but also increased NDMA formation during postchloramination. The net effect of these opposing trends on NDMA formation was water-specific.

  20. Rapid Removal of Tetrabromobisphenol A by Ozonation in Water: Oxidation Products, Reaction Pathways and Toxicity Assessment.

    Directory of Open Access Journals (Sweden)

    Ruijuan Qu

    Full Text Available Tetrabromobisphenol A (TBBPA is one of the most widely used brominated flame retardants and has attracted more and more attention. In this work, the parent TBBPA with an initial concentration of 100 mg/L was completely removed after 6 min of ozonation at pH 8.0, and alkaline conditions favored a more rapid removal than acidic and neutral conditions. The presence of typical anions and humic acid did not significantly affect the degradation of TBBPA. The quenching test using isopropanol indicated that direct ozone oxidation played a dominant role during this process. Seventeen reaction intermediates and products were identified using an electrospray time-of-flight mass spectrometer. Notably, the generation of 2,4,6-tribromophenol was first observed in the degradation process of TBBPA. The evolution of reaction products showed that ozonation is an efficient treatment for removal of both TBBPA and intermediates. Sequential transformation of organic bromine to bromide and bromate was confirmed by ion chromatography analysis. Two primary reaction pathways that involve cleavage of central carbon atom and benzene ring cleavage concomitant with debromination were thus proposed and further justified by calculations of frontier electron densities. Furthermore, the total organic carbon data suggested a low mineralization rate, even after the complete removal of TBBPA. Meanwhile, the acute aqueous toxicity of reaction solutions to Photobacterium Phosphoreum and Daphnia magna was rapidly decreased during ozonation. In addition, no obvious difference in the attenuation of TBBPA was found by ozone oxidation using different water matrices, and the effectiveness in natural waters further demonstrates that ozonation can be adopted as a promising technique to treat TBBPA-contaminated waters.

  1. 溴化蓖麻油多元醇合成及其制备的阻燃聚氨酯硬泡性能%The Synthesis of Bromine-containing Castor Oil Polyol and the Flame-retardant Polyurethane Foam Prooerties

    Institute of Scientific and Technical Information of China (English)

    何明; 罗振扬; 史以俊; 顾晓利; 张银萍

    2011-01-01

    A novel bromine-containing castor oil based polyol was prepared via the reaction of glycerin-exchanged castor oil and bromine.Structure of bromation product was analyzed by FT-IR.The basic characters of the polyol, such as viscosity, hydroxyl value and acid value were investigated.The effects of bromine-containing castor oil based polyols on properties of the rigid polyurethane foams, especially on their resistance to combustion, were studied by foam experiment, oxygen index, smoke density and horizontal burning experiments.It was compared with the foam prepared by RB-79 of Albemarle Corporation.It was found that the bromine-containing castor oil based polyols were effective for improving the resistance to combustion of rigid polyurethane foams, having the same effects with the commercial flame retardant RB-79 of Albemarle Corporation.%采用可再生的醇解蓖麻油多元醇为原料,与液溴进行加成反应制备溴化蓖麻油多元醇,通过红外光谱证实发生了溴化反应,并测定了产物粘度、羟值、酸值.通过发泡实验和氧指数、烟密度、水平燃烧等测试手段,考察了溴化蓖麻油基聚氨酯硬泡发泡参数和阻燃性质,并与工业级阻燃荆雅保RB-79制备的聚氨酯硬泡进行比较.结果表明,由溴化蓖麻油多元醇制备的泡沫体现出较好阻燃性能,与RB-79的阻燃效果相当.

  2. Health effects of disinfection by-products in chlorinated swimming pools.

    Science.gov (United States)

    Florentin, Arnaud; Hautemanière, Alexis; Hartemann, Philippe

    2011-11-01

    Increased attendance at swimming pools is correlated with higher input of organic and minerals pollutants introduced by swimmers in the swimming pool water. In most swimming pools, microbiological control is performed by disinfection with the addition of chlorine. Chlorine is now well-known to lead to the formation of many disinfection by-products (DBPs) including trihalomethanes and chloramines. The hypothesis of a link between the presence of eye and skin irritation syndromes in swimmers and contact with swimming pool water treated with chlorine was initially proposed by Mood (1953). During recent decades many epidemiological studies have described the importance of DBPs generated with natural or imported organic matter present in water. Many of these DBPs are suspected to be toxic or even carcinogenic. Trihalomethanes and haloacetic acid families are the most studied but others DBPs, like chloral hydrate, haloacetonitriles, N-nitrosodimethylamine and the bromate ion, are emerging compounds of interest. Epidemiological data about the risk of cancer are still controversial. However, numerous publications highlight a toxic risk especially the risk of allergy and respiratory symptoms for babies and elite swimmers. The few publications dedicated to risk assessment do not suggest increased risk, other than for elite swimmers. These publications are likely to underestimate the risk associated with DBPs because of the lack of data in the literature precludes the calculation of risk associated with certain compounds or certain pathways. Thus for regulations, the need to take into account the risks associated with disinfection by-products is now important without forgetting the need of the control of microbiological hazards in swimming pools. PMID:21885333

  3. The impact of lymphocyte isolation on induced DNA damage in human blood samples measured by the comet assay.

    Science.gov (United States)

    Bausinger, Julia; Speit, Günter

    2016-09-01

    The comet assay is frequently used in human biomonitoring for the detection of exposure to genotoxic agents. Peripheral blood samples are most frequently used and tested either as whole blood or after isolation of lymphocytes (i.e. peripheral blood mononuclear cells, PBMC). To investigate a potential impact of lymphocyte isolation on induced DNA damage in human blood samples, we exposed blood ex vivo to mutagens with different modes of genotoxic action. The comet assay was performed either directly with whole blood at the end of the exposure period or with lymphocytes isolated directly after exposure. In addition to the recommended standard protocol for lymphocyte isolation, a shortened protocol was established to optimise the isolation procedure. The results indicate that the effects of induced DNA strand breaks and alkali-labile sites induced by ionising radiation and alkylants, respectively, are significantly reduced in isolated lymphocytes. In contrast, oxidative DNA base damage (induced by potassium bromate) and stable bulky adducts (induced by benzo[a]pyrene-7,8-dihydrodiol-9,10-epoxide; BPDE) seem to be less affected. Our findings suggest that in vivo-induced DNA damage might also be reduced in isolated lymphocytes in comparison with the whole blood depending of the types of DNA damage induced. Because only small genotoxic effects can generally be expected in human biomonitoring studies with the comet assay after occupational and environmental exposure to genotoxic agents, any loss might be relevant and should be avoided. The possibility of such effects and their potential impact on variability of comet assay results in human biomonitoring should be considered when performing or evaluating such kind of studies. PMID:27154923

  4. Simultaneous removal of selected oxidized contaminants in groundwater using a continuously stirred hydrogen-based membrane biofilm reactor

    Institute of Scientific and Technical Information of China (English)

    Siqing Xia; Jun Liang; Xiaoyin Xu; Shuang Shen

    2013-01-01

    A laboratory trial was conducted for evaluating the capability of a continuously stirred hydrogen-based membrane biofilm reactor to simultaneously reduce nitrate (NO3--N),sulfate (SO42-),bromate (BrO3-),hexavalent chromium (Cr(Ⅵ)) and parachloronitrobenzene (p-CNB).The reactor contained two bundles of hollow fiber membranes functioning as an autotrophic biofilm carrier and hydrogen pipe as well.On the condition that hydrogen was supplied as electron donor and diffused into water through membrane pores,autohydrogenotrophic bacteria were capable of reducing contaminants to forms with lower toxicity.Reduction occurred within 1 day and removal fluxes for NO3--N,SO42-,BrO3-,Cr(Ⅵ),and p-CNB reached 0.641,2.396,0.008,0.016 and 0.031 g/(day.m2),respectively after 112 days of continuous operation.Except for the fact that sulfate was 37% removed under high surface loading,the other four contaminants were reduced by over 95%.The removal flux comparison between phases varying in surface loading and H2 pressure showed that decreasing surface loading or increasing H2 pressure would promote removal flux.Competition for electrons occurred among the five contaminants.Electron-equivalent flux analysis showed that the amount of utilized hydrogen was mainly controlled by NO2--N and SO42-reduction,which accounted for over 99% of the electron flux altogether.It also indicated the electron acceptor order,showing that nitrate was the most prior electron acceptor while sulfate was the second of the five contaminants.

  5. A novel copper(II) complex constructed with mixed ligands of biphenyl-4,4'-dicarboxylic acid (H 2bpdc) and dipyrido[3,2-d:2',3'-f]quinoxaline (Dpq): Synthesis, structure, electrochemistry and electrocatalysis

    Science.gov (United States)

    Lin, HongYan; Wang, XiuLi; Hu, HaiLiang; Chen, BaoKuan; Liu, GuoCheng

    2009-03-01

    A novel metal-organic framework [Cu 2(bpdc) 2(Dpq) 2(H 2O)]·H 2O ( 1) has been obtained from hydrothermal reaction of copper chloride with the mixed ligands [biphenyl-4,4'-dicarboxylic acid (H 2bpdc) and dipyrido[3,2-d:2',3'-f]quinoxaline (Dpq)], and structurally characterized by elemental analysis, IR, TG and single-crystal X-ray diffraction analysis. The unique feature is that there simultaneously exist two kinds of one-dimensional (1-D) zigzag polymeric chains in complex 1. Moreover, the 1-D polymeric chains are ultimately packed into a three-dimensional (3-D) supramolecular framework through two different hydrogen bonding interactions. The adjacent different chains are linked by C-H⋯O hydrogen bonding interactions, and the same kind chains are further connected through C-H⋯π stacking interactions. Additionally, the complex 1 was used as solid bulk-modifier to fabricate renewable carbon paste electrode (Cu-CPE) by the direct mixing method. The electrochemical behavior and electrocatalysis of Cu-CPE have been studied in detail. The results indicate that Cu-CPE give one-electron quasi-reversible redox waves in potential range of 400 to -300 mV due to the metal copper ion Cu(II)/Cu(I). The Cu-CPE showed good electrocatalytic activity toward the reduction of the bromate, nitrite and hydrogen peroxide. The electrocatalytic reduction peak currents of KBrO 3, KNO 2 and H 2O 2 showed a linear dependence on their concentrations. All of the results revealed that the Cu-CPE had a good reproducibility, remarkable long-term stability and especially good surface renewability by simple mechanical polishing in the event of surface fouling, which is important for practical application.

  6. Determination of trace uranium by resonance fluorescence method coupled with photo-catalytic technology and dual cloud point extraction.

    Science.gov (United States)

    Li, Jiekang; Li, Guirong; Han, Qian

    2016-12-01

    In this paper, two kinds of salophens (Sal) with different solubilities, Sal1 and Sal2, have been respectively synthesized, and they all can combine with uranyl to form stable complexes: [UO2(2+)-Sal1] and [UO2(2+)-Sal2]. Among them, [UO2(2+)-Sal1] was used as ligand to extract uranium in complex samples by dual cloud point extraction (dCPE), and [UO2(2+)-Sal2] was used as catalyst for the determination of uranium by photocatalytic resonance fluorescence (RF) method. The photocatalytic characteristic of [UO2(2+)-Sal2] on the oxidized pyronine Y (PRY) by potassium bromate which leads to the decrease of RF intensity of PRY were studied. The reduced value of RF intensity of reaction system (ΔF) is in proportional to the concentration of uranium (c), and a novel photo-catalytic RF method was developed for the determination of trace uranium (VI) after dCPE. The combination of photo-catalytic RF techniques and dCPE procedure endows the presented methods with enhanced sensitivity and selectivity. Under optimal conditions, the linear calibration curves range for 0.067 to 6.57ngmL(-1), the linear regression equation was ΔF=438.0 c (ngmL(-1))+175.6 with the correlation coefficient r=0.9981. The limit of detection was 0.066ngmL(-1). The proposed method was successfully applied for the separation and determination of uranium in real samples with the recoveries of 95.0-103.5%. The mechanisms of the indicator reaction and dCPE are discussed.

  7. Cellular distribution of cell cycle-related molecules in the renal tubules of rats treated with renal carcinogens for 28 days: relationship between cell cycle aberration and carcinogenesis.

    Science.gov (United States)

    Taniai, Eriko; Hayashi, Hitomi; Yafune, Atsunori; Watanabe, Maiko; Akane, Hirotoshi; Suzuki, Kazuhiko; Mitsumori, Kunitoshi; Shibutani, Makoto

    2012-09-01

    Some renal carcinogens can induce karyomegaly, which reflects aberrant cell division in the renal tubules, from the early stages of exposure. To clarify the cell cycle-related changes during the early stages of renal carcinogenesis, we performed immunohistochemical analysis of tubular cells in male F344 rats treated with carcinogenic doses of representative renal carcinogens for 28 days. For this purpose, the karyomegaly-inducing carcinogens ochratoxin A (OTA), ferric nitrilotriacetic acid, and monuron, and the non-karyomegaly-inducing carcinogens tris(2-chloroethyl) phosphate and potassium bromate were examined. For comparison, a karyomegaly-inducing non-carcinogen, p-nitrobenzoic acid, and a non-carcinogenic non-karyomegaly-inducing renal toxicant, acetaminophen, were also examined. The outer stripe of the outer medulla (OSOM) and the cortex + OSOM were subjected to morphometric analysis of immunoreactive proximal tubular cells. Renal carcinogens, irrespective of their karyomegaly-inducing potential, increased proximal tubular cell proliferation accompanied by an increase in topoisomerase IIα-immunoreactive cells, suggesting a reflection of cell proliferation. Karyomegaly-inducing carcinogens increased nuclear Cdc2-, γH2AX-, and phosphorylated Chk2-immunoreactive cells in both areas, the former two acting in response to DNA damage and the latter one suggestive of sustained G₂. OTA, an OSOM-targeting carcinogen, could easily be distinguished from untreated controls and non-carcinogens by evaluation of molecules responding to DNA damage and G₂/M transition in the OSOM. Thus, all renal carcinogens examined facilitated proximal tubular proliferation by repeated short-term treatment. Among these, karyomegaly-inducing carcinogens may cause DNA damage and G₂ arrest in the target tubular cells.

  8. Utilization of a Green Brominating Agent for the Spectrophotometric Determination of Pipazethate HCl in Pure Form and Pharmaceutical Preparations

    Directory of Open Access Journals (Sweden)

    Ayman A. Gouda

    2013-01-01

    Full Text Available Five simple, accurate, and sensitive spectrophotometric methods (A–E have been described for the indirect assay of pipazethate HCl (PZT either in pure form or in pharmaceutical preparations. The proposed methods are based on the bromination of pipazethate HCl with a solution of excess bromate-bromide mixture in hydrochloric acid medium and subsequent estimation of the residual bromine by different reaction schemes. In the first three methods (A–C, the determination of the residual bromine is based on its ability to bleach the color of methyl orange, indigo carmine, or thymol blue dyes and measuring the absorbance at 520, 610, and 550 nm for methods A, B, and C, respectively. Methods D and E involves treating the unreacted bromine with a measured excess of iron(II, and the remaining iron(II is complexed with 1,10-phenanthroline, and the increase in absorbance is measured at 510 nm for method D and the resulting iron(III is complexed with thiocyanate and the absorbance is measured at 480 nm for method E. The different experimental parameters affecting the development and stability of the color are carefully studied and optimized. Regression analysis of the Beer-Lambert plots showed good correlation in the concentration ranges of 0.5–8.0 μg . The apparent molar absorptivity, Sandell's sensitivity, detection and quantitation limits were evaluated. The proposed methods have been applied and validated successfully for the analysis of the drug in its pure form and pharmaceutical formulations with mean recoveries of 99.94%–100.15% and relative standard deviation ≤1.53. No interference was observed from a common pharmaceutical adjuvant. Statistical comparison of the results with the reference method shows excellent agreement and indicates no significant difference in accuracy and precision.

  9. Determination of trace uranium by resonance fluorescence method coupled with photo-catalytic technology and dual cloud point extraction.

    Science.gov (United States)

    Li, Jiekang; Li, Guirong; Han, Qian

    2016-12-01

    In this paper, two kinds of salophens (Sal) with different solubilities, Sal1 and Sal2, have been respectively synthesized, and they all can combine with uranyl to form stable complexes: [UO2(2+)-Sal1] and [UO2(2+)-Sal2]. Among them, [UO2(2+)-Sal1] was used as ligand to extract uranium in complex samples by dual cloud point extraction (dCPE), and [UO2(2+)-Sal2] was used as catalyst for the determination of uranium by photocatalytic resonance fluorescence (RF) method. The photocatalytic characteristic of [UO2(2+)-Sal2] on the oxidized pyronine Y (PRY) by potassium bromate which leads to the decrease of RF intensity of PRY were studied. The reduced value of RF intensity of reaction system (ΔF) is in proportional to the concentration of uranium (c), and a novel photo-catalytic RF method was developed for the determination of trace uranium (VI) after dCPE. The combination of photo-catalytic RF techniques and dCPE procedure endows the presented methods with enhanced sensitivity and selectivity. Under optimal conditions, the linear calibration curves range for 0.067 to 6.57ngmL(-1), the linear regression equation was ΔF=438.0 c (ngmL(-1))+175.6 with the correlation coefficient r=0.9981. The limit of detection was 0.066ngmL(-1). The proposed method was successfully applied for the separation and determination of uranium in real samples with the recoveries of 95.0-103.5%. The mechanisms of the indicator reaction and dCPE are discussed. PMID:27380304

  10. 甲基橙催化褪色光度法测定阿莫西林%Catalytic fade spectrophotometric determination of amoxicillin with helianthine system

    Institute of Scientific and Technical Information of China (English)

    熊海涛

    2012-01-01

    在硫酸介质中,阿莫西林可以催化溴酸钾氧化甲基橙使其褪色,且褪色程度(△A)与阿莫西林浓度在一定范围内符合朗伯-比尔定律,据此建立了催化光度法测定阿莫西林的新方法.在最优试验条件下,阿莫西林含量在0.70 ~ 9.0 μg/mL范围内与吸光度呈良好的线性关系,检出限0.33 μg/mL,回收率在96%~104%之间.可用于胶囊中阿莫西林含量的测定,结果满意.%Based on the catalytic effects of amoxicillin on the oxidation reactions of helianthine by potassium bromate under sulphuric acid medium and the fading obeyed the Lambert-Beer law with the concentration of amoxicillin in a certain range, a new catalytic spectrophotometric method was developed. Under the optimal conditions, the detection limit for amoxicillin was 0.33 μg/mL and the recovery rate was 96% ~ 104%. And the linear range for amoxicillin was 0.70 ~9.00 μg/mL. The method has been applied to determine amoxicillin in capsule with satisfying results.

  11. UV/H2O2联用工艺去除水中微量有机污染物的中试研究%Pilot study of UV/H2O2 combined process on removing micro organic pollutants in water

    Institute of Scientific and Technical Information of China (English)

    夏萍; 叶辉; 周新宇; 张东; 王铮

    2012-01-01

    为了考察UV/H2O2工艺对微量有机物的去除效果,在砂滤池出水后接UV/H2O2高级氧化中试设备,并投加了特征污染物(阿特拉津、臭味物质2-MIB与Geosmine).结果表明,UV/H2O2工艺对Geosmine去除效果最好,去除率能达到90%以上,对MIB和阿特拉津的去除效果比较接近,去除率均在50%以上,对UV254的去除率为20%~38%.在UV/H2O2工艺中无溴酸盐生成.%To study the removal efficiency of UV/H2O2 process on micro organic pollutants, UV/H2O2 pilot equipment was used to treat the sedimentation effluent dosed with target pollutants (including Atrazine, odor matter 2 - MIB, and Geosmine). The results showed: UV/H2O2 had the best efficiency on removing Geosmine with the removal rate over 90%. The removal effect of MIB and Atrazine was alike, and the removal rates both reached over 50%. The removal rate of UV254 was 20%-38%. No bromate was formed in the UV/H2O2 process.

  12. Titrimetric, spectrophotometric and kinetic methods for the assay of atenolol using bromate–bromide and methyl orange

    Directory of Open Access Journals (Sweden)

    KANAKAPURA BASAVAIAH

    2006-05-01

    Full Text Available Three new methods have been developed for the determination of atenolol in bulk drug and in tablet formulation. The methods are based on the oxidation–bromination reaction of the drug by bromine, generated in situ by the action of acid on a bromate–bromide mixture. In the titrimetric method, the drug is treated with a known excess of bromate–bromide mixture in hydrochloric acid medium, followed by the determination of the unreacted bromine iodometrically. The spectrophotometric method involves the addition of a measured excess of bromate–bromide reagent in hydrochloric acid medium to atenolol, and after ensuring the reaction had gone to completion, the unreacted bromine is treated with a fixed amount of methyl orange, and absorbance measured at 520 nm. The absorbance was found to increase linearly with increasing concentration of atenolol. The kinetic method depends on the existence of a linear relationship between the concentration of the drug and the time of the oxidation–bromination reaction, as indicated by the bleaching of methyl orange acid colour. The working conditions were optimized. The titrimetric method is based on a 1:1 reaction stoichiometry (atenolol:bromate and is applicable over the 3–20 mg range. The spectrophotometric method permits micro determination of the drug (0.5–4.0 mg ml-1with an apparentmolar absorptivity of 4.13x104 lmol-1 cm-1 and detection limit of 0.07 mg ml-1. The kinetic method is applicable in the concentration range 5–25 mg ml-1 with a detection limit of 3.72 mg ml-1. The proposed methods were successfully applied to the determination of atenolol in tablet preparations with mean recoveries of 97.63 to 101.78 %. The reliability of the assay was established by parallel determination by the reference method and by recovery studies using the standard addition technique.

  13. Development of new radiation resistant, fire-retardant cables. [Gamma radiation

    Energy Technology Data Exchange (ETDEWEB)

    Hagiwara, Ko; Morita, Yosuke; Udagawa, Takashi (Japan Atomic Energy Research Inst., Takasaki, Gunma. Takasaki Radiation Chemistry Research Establishment); Fujimura, Shun-ichi; Oda, Eisuke

    1982-12-01

    For the cables for nuclear facilities, radiation resistance and fire-retardation are severely required. The authors took note of the fact that even in the existing cables for nuclear power plants, their mechanical properties are greatly degraded by the exposure to large dose (for example, 200 Mrad in PWR testing conditions), and attempted the improvement. They employed a new additive, bromated acenaphthylene condensate (con-BACN), which effectively gives radiation resistance and also is a good flame retarder, to be compounded to an insulation material, and examined the characteristics. In this paper, the features of con-BACN and the investigation of fire-retardant EPDM composition are described. As an initial composition, a small amount of zinc white, sulphur, stearic acid, noclac 224 (Ouchi-Shinko Chemicals, Co.), and antimony trioxide, 100 parts of tale and 45 parts of con-BACN were added to 100 parts of EPDM (propylene content 34 %, Japan Synthetic Rubber Co.). As the antiaging agent, it was decided to use phenol series No. 3 as a result of test. The fire-retardant EP rubber-composed cable was produced for trial, its insulation being fabricated, using a Furukawa's pressurized salt bath continuous vulcanizer. The tests of ..gamma..-irradiation, simulated LOCA and combustion were carried out, and the test results are reported. It was indicated that the cable resisted against high dose several times as much as 200 Mrad, and was suitable for the applications, in which the mechanical properties such as bending are required to be maintained after radiation exposure. It was also found that con-BACN was safe, and its properties of decomposition, concentration and acute toxicity were all very low.

  14. 四种国标测定氨氮方法述评%Evaluation of Four GB Methods about Ammonia Determination

    Institute of Scientific and Technical Information of China (English)

    陈岚

    2014-01-01

    According to practical experience, we evaluate the character of four GB methods about ammonia determination. We improve the determination limit and solve the problem of insufficient oxidant adjunction and high salinity affecting by diluting a small amount of sample. However, if the sample has a high ammonia concentration, salicylic acid method can be adopted instead of Nessler's method to avoid mercury pollution. If the sample has a low ammonia concentration, bromate method can be used to replace phenol method that will overcome the shortcoming of slow reaction speed of the latter. QUAATRO continuous flow analyzer is a better instrument that may be used to replace the above methods.%作者结合工作经验,评述了测定氨氮的四种国家标准的特点,采用少取水样量稀释之,可以提高测定浓度上限,也解决了氧化剂加量不足或盐度大的问题。因而,对高浓度的样品(0.5-50 mg/L)可以用水杨酸法取代纳氏法,避免了后者汞的污染;对低浓度样品(<0.5 mg/L),可以用次溴酸盐法取代苯酚法,克服了后者反应太慢的缺点。QUAATRO连续流动分析仪是可以取代上述方法较好的仪器。

  15. Zirconium-based metal organic frameworks: Highly selective adsorbents for removal of phosphate from water and urine

    International Nuclear Information System (INIS)

    Phosphate is one of the most concerning compounds in wastewater streams and a main nutrient that causes eutrophication. To eliminate the phosphate pollution, Metal Organic Frameworks (MOFs) are proposed in this study as adsorbents to remove phosphate from water. The zirconium-based MOF, UiO-66, was selected as representative MOF given its exceptional stability in water. To investigate the effect of an amine functional group, UiO-66-NH2 was also prepared using an amine-substituted ligand. The adsorption kinetics and isotherm reveal that UiO-66-NH2 exhibited higher adsorption capacities than UiO-66 possibly due to the amine group. However, the interaction between phosphate and zirconium sites of UiO MOFs might be the primary factor accounting for the phosphate adsorption to UiO MOFs. UiO MOFs also exhibited a high selectivity towards phosphate over other anions such as bromate, nitrite and nitrate. Furthermore, UiO MOFs were found to adsorb phosphate and to completely remove diluted phosphate in urine. We also found that UiO MOFs could be easily regenerated and re-used for phosphate adsorption. These findings suggest that UiO MOFs can be effective and selective adsorbents to remove phosphate from water as well as urine. - Highlights: • UiO-66 as the first type of MOFs was used to remove phosphate from water and urine. • The amine group in UiO MOFs was found to enhance the phosphate adsorption. • UiO-66 exhibited a high adsorption selectivity towards phosphate over other anions. • UiO-66 could be easily regenerated and re-used with 85% regeneration efficiency

  16. Fabrication of CdS/CdTe solar cells with transparent p-type conductive BaCuSeF back contact

    Science.gov (United States)

    Yamamoto, Koichi; Sakakima, Hiroshi; Ogawa, Yohei; Hosono, Aikyo; Okamoto, Tamotsu; Wada, Takahiro

    2015-08-01

    BaCuSeF films were applied to CdS/CdTe solar cells as back electrodes. The interfaces between the CdTe and BaCuSeF layers in the CdS/CdTe solar cells with BaCuSeF back contact deposited at substrate temperatures (TS) of 200 and 300 °C were analyzed by transmission electron microscopy (TEM) and energy dispersive X-ray spectroscopy (EDS). We clearly observed many dislocations in the CdTe layer in the CdS/CdTe solar cell with the BaCuSeF layer deposited at TS = 300 °C. We also observed a reaction layer of Cu2.72Te2 between the BaCuSeF and CdTe layers in both solar cells. We concluded that (1) the substrate temperature for the pulsed laser deposition of the BaCuSeF layer and (2) the interface between the CdTe and BaCuSeF layers are important factors for the performance of the CdTe solar cells. We obtained high conversion efficiency of 8.31% for a solar cell with a BaCuSeF layer deposited at TS = 200 °C on a CdTe surface etched in a NH3 aqueous solution. The highest conversion efficiency of 9.91% was obtained for a solar cell with a CdTe surface etched in a bromide-bromate solution.

  17. Palladium nanoparticles encapsulated in core-shell silica: A structured hydrogenation catalyst with enhanced activity for reduction of oxyanion water pollutants

    KAUST Repository

    Wang, Yin

    2014-10-03

    Noble metal nanoparticles have been applied to mediate catalytic removal of toxic oxyanions and halogenated hydrocarbons in contaminated water using H2 as a clean and sustainable reductant. However, activity loss by nanoparticle aggregation and difficulty of nanoparticle recovery are two major challenges to widespread technology adoption. Herein, we report the synthesis of a core-shell-structured catalyst with encapsulated Pd nanoparticles and its enhanced catalytic activity in reduction of bromate (BrO3-), a regulated carcinogenic oxyanion produced during drinking water disinfection process, using 1 atm H2 at room temperature. The catalyst material consists of a nonporous silica core decorated with preformed octahedral Pd nanoparticles that were further encapsulated within an ordered mesoporous silica shell (i.e., SiO2@Pd@mSiO2). Well-defined mesopores (2.3 nm) provide a physical barrier to prevent Pd nanoparticle (6 nm) movement, aggregation, and detachment from the support into water. Compared to freely suspended Pd nanoparticles and SiO2@Pd, encapsulation in the mesoporous silica shell significantly enhanced Pd catalytic activity (by a factor of 10) under circumneutral pH conditions that are most relevant to water purification applications. Mechanistic investigation of material surface properties combined with Langmuir-Hinshelwood modeling of kinetic data suggest that mesoporous silica shell enhances activity by promoting BrO3- adsorption near the Pd active sites. The dual function of the mesoporous shell, enhancing Pd catalyst activity and preventing aggregation of active nanoparticles, suggests a promising general strategy of using metal nanoparticle catalysts for water purification and related aqueous-phase applications.

  18. DRINKING WATER DISINFECTION BYPRODUCTS:CHEMICAL CHARACTERIZATION AND TOXICITY%饮用水消毒副产物:化学特征与毒性

    Institute of Scientific and Technical Information of China (English)

    赵玉丽; 李杏放

    2011-01-01

    Disinfection of drinking water is essential to and effective for the prevention of water-borne diseases.While achieving deactivation of microbial pathogens to minimize the acute risk, an unintentional consequence is the formation of disinfection byproducts (DBPs) resulting from reactions of disinfectants with natural organic materials (NOMs) in water. Epidemiological studies show potential associations of increased risk of bladder cancer and adverse health effects with DBPs. Balancing microbial risk with chemical risk is challenging for public health protection. Currently, the most commonly used disinfectants are chlorine, chlorine dioxide,chloramines and ozone. Here we provide an overview of chemical characterization, toxicity and analytical methods of 10 classes of DBPs, including trihalomethanes ( THMs), haloacefic acids ( HAAs), bromate ( BrO3- ), chlorite ( ClO2- ), haloacetonitriles (HANs), mutagen X (MX), halonitromethane ( HNMs), iodo acids (IAs), N-nitrosodimethylamines (NMs) and halobenzoquinones (HBQs). We will discuss the challenges and opportunities in the research of DBPs and health effects.%饮用水消毒过程中消毒剂与天然有机物(NOMs)反应生成消毒副产物(DBPs).本文针对氯、氯胺、二氧化氯、臭氧4种主要消毒方式产生的消毒副产物,综述了10类DBPs的化学特性、毒性和分析方法.具体包括:三卤甲烷(THMs)、卤乙酸(HAAs)、溴酸盐(BrO3-)、亚氯酸盐(CIO2-)、卤乙腈(HANs)、致诱变化合物(MX)、卤代硝基甲烷(HNMs)、碘代酸(Ias)、亚硝胺(NMs)以及卤代对苯醌(HBQs).

  19. 天津开发区净水厂三期工程紫外线消毒系统应用研究%Application study on UV disinfection system in the third stage project of Tianjin development zone Water Treatment Plant

    Institute of Scientific and Technical Information of China (English)

    聂雪彪; 刘文君; 何凤华

    2011-01-01

    The UV - chlorine disinfection process was employed in the third stage project in Tianjin development zone water treatment plant. The production water and pipe - network water were tested, and the results showed: Cryptozoite, Giardia, coronavirus and adenovirus were not found; the coliform, total plate count, HPC (Heterotrophic bacteria count), bromate, haloacetic acids, and trihalomethanes in production water and pipe-network water all met the standards; when UVT (UV transmittance) in UV disinfection reactor was relatively high (UVT=95%), the power of UV disinfection equipment could be lowered; there was still some space for the decrease of chlorine dosage in the UV-chlorine disinfection process.%天津开发区净水厂三期工程采用紫外线联合氯消毒工艺,对主要工艺出水及管网水进行检测,未检出隐孢子虫、贾第鞭毛虫、冠状病毒和腺病毒;出厂水及管网水中总大肠菌群、菌落总数、HPC(Heterotrophic bacteria count,异养菌计数),以及溴酸盐、卤乙酸、三卤甲烷等理化指标均达到相关标准要求;紫外线反应器进水UVT(UV transmittance,紫外透光率)较高时(如UVT=95%),可降低紫外线消毒设备功率;联合消毒的加氯量经初步探究有一定的降低空间.

  20. Catalytic discoloring spectrophotometry determination of trace element germanium in Chinese herbal medicine (herba hedyotis)%催化褪色光度法测定中草药白花蛇舌草中的微量锗

    Institute of Scientific and Technical Information of China (English)

    杨慧; 丁良; 张宝淋; 袁丽云; 董晓东

    2015-01-01

    目的:利用催化褪色光度法测定中草药白花蛇舌草中微量元素锗。方法用超声波清洗仪提取中草药白花蛇舌草中微量元素锗,并用催化褪色光度法测定锗元素的含量。研究痕量锗在稀硫酸介质中催化加速溴酸钾、过氧化氢与中性红之间的反应,建立催化光度法测定痕量锗的方法。结果本实验测得中草药白花蛇舌草中无机锗(Ⅳ)含量为0.0248μg/g。结论该法灵敏度、精密度均能满足检测工作的需要。%Objective To explore a catalytic spectrophotometic method for the quantitative determination of trace elements germanium in Chinese herbal medicine (herba hedyotis).Methods Extraction of trace element germanium inherba hedyotis was examined by using ultrasonic cleaning equipment, and the content was determined by catalytic discoloring spectrophotometry. The reaction was studied, trace germanium (IV) could accelerate potassium bromate and hydrogen peroxide oxidize neutral red in H2SO4 medium, the established method could be used to determine catalytic spectrophotometric determination of trace germanium (IV).Results The results of this experiment indicated that inorganic germanium (IV) content in Chinese herbal medicine spreadingherba hedyotis was 0.024 8 μg/g.Conclusion The sensitivity, the precision can meet the needs of the testing work well.

  1. Determination of Vanadium by New Catalytic Polarographic Method%催化动力学极谱法测定痕量钒

    Institute of Scientific and Technical Information of China (English)

    王术皓; 杜凌云; 张爱梅; 张美芹

    2001-01-01

    在硫酸介质中,以酒石酸为活化剂,痕量钒对溴酸钾氧化甲基橙的反应有极强的催化作用,以极谱法监测催化反应过程中甲基橙及其氧化产物浓度的变化,建立了双峰指示催化动力学极谱法测定痕量钒的新方法。方法的线性范围为0.23~3.70μg/L,检出限为0.17μg/L。方法已用于食品及水样中痕量钒的测定。%A new catalytic polarographic method for determination of traceamounts of vanadium(Ⅴ) was proposed .The method was based on the catalytic effects of V(Ⅴ) on the oxidation of methy1 orange by bromate in sulfuric acid medium with tartaric acid as an activator. The reaction was monitored by measuring the decrease of the peak height at -0.62V or the increase of the peak height at -0.52V. The linear range is 0.23~3.70 μg/L for vanadium(Ⅴ), with detection limit of 0.17 μg/L. The method was used to determine trace vanadium in food and water samples with satisfactory results.

  2. Reclaimed water quality during simulated ozone-managed aquifer recharge hybrid

    KAUST Repository

    Yoon, Min

    2014-06-17

    A synergistic hybrid of two treatment processes, managed aquifer recharge (MAR) combined with ozonation, was proposed for wastewater reclamation and water reuse applications. Batch reactor and soil-column experiments were performed to evaluate reclaimed water quality using various chemical and bacterial analyses. The ozone process was optimized at low ozone dose (0.5 mg O3/mg DOC) based on the control of N-nitrosodimethylamine (<5 ng L-1) and bromate (<10 μg L-1), and applied prior to (i.e., O3-MAR) and after MAR (i.e., MAR-O3). This work demonstrates that effluent organic matter (EfOM) and trace organic contaminants (TOrCs) are effectively removed during the hybrid process of MAR combined ozonation, compared to MAR only. Based on fluorescence excitation-emission matrices analyses, both MAR and ozonation reduce soluble microbial (protein-like) products while only ozonation contributes in reducing humic and fulvic substances. Even at low ozone dose of 0.5 mg O3/mg DOC, the O3-MAR hybrid significantly reduced UV absorbance by ≥2 m-1, BDOC by ≥64 %, and total (Σ) TOrC concentrations by ≥70 % in the effluent water quality. However, no significant improvement (<10 %) in the removal of Σ16 TOrC concentrations was observed for the increased ozone dose at 1.0 mg O3/mg DOC during MAR combined ozonation processes. Overall, O3-MAR was effective by 10-30 % in treating effluent water than MAR based on DOC, UV254 nm EfOM, TOrC and bacterial analyses. In addition, MAR-O3 was better than O3-MAR for the reduction of fluorescence (close MQ), TOrCs (≥74 %) and total bacteria cell concentrations (>3 log reduction). Therefore, implementing MAR prior to ozonation appears to remove the bio-amenable compounds that react rapidly with ozone, thereby reducing oxidant demand and treatment efficiency. © 2014 Springer-Verlag Berlin Heidelberg.

  3. Synthesis and Characterization of Chitosan Oligosaccharide-graft-Acrylic Acid Biodegradable Crosslinker%丙烯酸接枝壳寡糖生物可降解交联剂的合成与表征

    Institute of Scientific and Technical Information of China (English)

    苏宇佳; 赵骞; 孙建中

    2012-01-01

    在1-乙基-3-(3-二甲氨丙基)碳化二亚胺盐酸盐(EDC)和N-羟基琥珀酰亚胺(NHS)催化作用下,采用水溶性的壳寡糖(CSO)与丙烯酸(AA)发生N-酰化反应,制备出一种新型水溶性可降解水凝胶交联剂——丙烯酸接枝壳寡糖(CSO-g-AA).用CSO-g-AA与丙烯酰胺单体共聚制备了聚丙烯酰胺水凝胶.该水凝胶可在蜗牛酶作用下降解为水溶性直链聚丙烯酰胺.采用1H-NMR、红外吸收光谱法对CSO-g-AA结构进行表征,用溴酸钾-溴化钾滴定法定量分析了CSO-g-AA中不饱和双键的含量.结果表明:该交联剂中不饱和双键的接枝率约为4%,在适当的温度、pH值和酶浓度下水凝胶经72 h完全降解.%A new water soluble and biodegradable crosslinker of chitosan oligosaccharide-graft-acrylic acid (CSO-g-AA) was synthesized through the acrylyl reaction of amino groups in the chitosan oligosaccharide (CSO) chains with acrylic acid (AA) catalyzed by 1-ethyl-3-(3-dimethylaminopropyl)-carbodiimidehydro-chloride (EDC) and N-hydroxysuccinimide (NHS). Polyacrylamide (PAM) hydrogels were prepared by copolymerization of acrylamide and CSO-g-AA. CSO-g-AA was structurally characterized by Fourier transform infrared spectroscopy (FT-IR) and H-1 nuclear magnetic resonance (1H-NMR) spectroscopy. The content of unsaturated double bond in CSO-g-AA was quantitatively analysed by titration analysis using potassium bromate (KBrO) and potassium bromide (KBr). The results show that the grafting ratio of unsaturated double bond in CSO-g-AA is about 4%. At a proper temperature, pH value and concentration of enzyme, the PAM hydrogels can be degraded to water soluble polyacrylamide chains in 72 h under the catalysis of snailase.

  4. Investigation of the Oxidation Reaction of O3 with Bromide Ion in Aqueous Solution%水溶液中臭氧和溴离子的反应研究

    Institute of Scientific and Technical Information of China (English)

    俞潇婷; 张家辉; 潘循皙; 张仁熙; 侯惠奇

    2012-01-01

    The reaction mechanism of O3 with bromide ion in aqueous solution was studied by ion chromatography and UV-Vis spectrometry instruments.Ion chromatography analysis showed that only 10% of Br-which was oxidized by ozone was formed into bromate ion.The results demonstrated that the final products of the oxidation reaction were identified as Br2 and Br-3 except for BrO-3.The formation of Br-3 which was yielded from the reaction of Br2 with Br-was the major process in the reaction of Br-attacked by O3.The characteristic absorption spectrum of Br-3 with an absorption peak at 260 nm was also investigated.The results may provide helpful information about the mechanism of the oxidation reaction of Br-with O3 and fate of Br-or its derivatives in the environment by the oxidation processes.%为探明O3氧化Br-的反应机制,采用离子色谱、PDA紫外-可见光度仪研究了水中Br-被O3氧化的反应过程.离子色谱分析表明,被氧化的Br-中只有约10%被O3氧化成BrO3-.进一步研究表明,除了生成BrO3-外,Br-被O3氧化过程中还产生了Br2,Br2又与溶液中存在的Br-结合形成Br3-,并首次得到了Br3-的吸收光谱,测得Br3-的最大吸收峰λmax为260 nm,提出了Br-与O3的基元反应.该研究补充和完善了O3氧化Br-的反应机制,也为O3处理含Br-水时Br-的归趋提供了有益信息.

  5. Efficiency and energy requirements for the transformation of organic micropollutants by ozone, O3/H2O2 and UV/H2O2.

    Science.gov (United States)

    Katsoyiannis, Ioannis A; Canonica, Silvio; von Gunten, Urs

    2011-07-01

    The energy consumptions of conventional ozonation and the AOPs O(3)/H(2)O(2) and UV/H(2)O(2) for transformation of organic micropollutants, namely atrazine (ATR), sulfamethoxazole (SMX) and N-nitrosodimethylamine (NDMA) were compared. Three lake waters and a wastewater were assessed. With p-chlorobenzoic acid (pCBA) as a hydroxyl radical ((•)OH) probe compound, we experimentally determined the rate constants of organic matter of the selected waters for their reaction with (•)OH (k(OH,DOM)), which varied from 2.0 × 10(4) to 3.5 × 10(4) L mgC(-1) s(-1). Based on these data we calculated (•)OH scavenging rates of the various water matrices, which were in the range 6.1-20 × 10(4) s(-1). The varying scavenging rates influenced the required oxidant dose for the same degree of micropollutant transformation. In ozonation, for 90% pCBA transformation in the water with the lowest scavenging rate (lake Zürich water) the required O(3) dose was roughly 2.3 mg/L, and in the water with the highest scavenging rate (Dübendorf wastewater) it was 13.2 mg/L, corresponding to an energy consumption of 0.035 and 0.2 kWh/m(3), respectively. The use of O(3)/H(2)O(2) increased the rate of micropollutant transformation and reduced bromate formation by 70%, but the H(2)O(2) production increased the energy requirements by 20-25%. UV/H(2)O(2) efficiently oxidized all examined micropollutants but energy requirements were substantially higher (For 90% pCBA conversion in lake Zürich water, 0.17-0.75 kWh/m(3) were required, depending on the optical path length). Energy requirements between ozonation and UV/H(2)O(2) were similar only in the case of NDMA, a compound that reacts slowly with ozone and (•)OH but is transformed efficiently by direct photolysis. PMID:21645916

  6. An assessment of the influence of multiple stressors on the Vaal River, South Africa

    Science.gov (United States)

    Wepener, V.; van Dyk, C.; Bervoets, L.; O'Brien, G.; Covaci, A.; Cloete, Y.

    community structures. This was related to decreased fish health as demonstrated by increased oxidative stress due to exposure to metals such as copper and nickel as well as organic pollutants such as PCBs, HCHs and bromated flame retardants. This study clearly demonstrates the importance of the inclusion of higher tier assessment endpoints to elucidate the effects of multiple stressors in aquatic ecosystems. The study further allowed for the identification of specific effect endpoints that need to be included in future monitoring programmes such as viral immunoassays.

  7. A Novel Method to Prepare Furfural from Xylose over Solid Acid Catalysts ( SO42-/TiO2)%固体酸催化剂SO42-/TiO2催化木糖脱水制备糠醛的新方法

    Institute of Scientific and Technical Information of China (English)

    吴树新; 孙涛

    2012-01-01

    探索了以固体超强酸SO42 -/TiO2为催化剂,催化木糖脱水环化制备糠醛的新方法.以TiCl4乙醇溶液(体积比1∶1)作为钛源、以浓氨水作为沉淀剂制备二氧化钛,硫酸溶液作为浸渍液,制备了SO42 -/TiO2固体超强酸.采用二溴化法(溴酸钠-溴化钠)对糠醛产量进行分析,研究了反应条件和催化剂制备过程中硫酸浸渍液浓度、焙烧温度等对糠醛产率的影响.结果表明,使用固体超强酸作催化剂,在最佳条件下,糠醛产率达到42.6%,而同样条件下用硫酸作催化剂糖醛产率只有15.6%.%Dehydration of xylose into furfural was performed with solid super acid(S042-/Ti02) as catalyst. The preparation of SO42-/TiO2 was made using TiCl4 in alcohol ( V(TiCl4) : V(alcohol) = 1:1) as titanium source,strong ammonia as precipitant and H2SO4 as impregnating solution. Dehydration of xylose into furfural was carried out in 25 mL degestion tube with oil-bath heating. The yield of furfural were determined in the method of two brominated (sodium bromate-sodium bromide).The conditions of preparation of furfural and the influence of its yield were researched. The results show that the catalyst is essential in the preparation of furfural for xylose dehydration reaction.The yield of furfural reaches to 42.6 % when solid super acid SO42-VTiO2 used as catalyst, while it is only 15.6 % at the same conditions using H2SO4 as catalyst.

  8. O3-BAC工艺处理太湖原水的技术研究和生产实践%Technical study and production practice of the O3-BAC to treat the raw water from Taihu lake

    Institute of Scientific and Technical Information of China (English)

    蒋福春; 张雪; 李琴; 陈玲瑚; 周洵

    2011-01-01

    以苏州相城水厂臭氧—生物活性炭(O3-BAC)工艺的应用情况为基础,分析和探讨该工艺实际应用效果和运行管理要求.结果表明:在常规工艺基础上,有机物去除率可提高20%~40%,氯消毒副产物降低近40%,出厂水水质稳定;O3-BAC工艺能有效应对藻类暴发和原水水质短暂突变等事件;水温对生物活性炭的处理效果影响较大,夏季较冬季理想;运行管理中应重点关注和解决活性炭寿命、溴酸盐、水质生物安全性及冬季高氨氮的处理等问题;针对太湖原水而言,O3-BAC工艺具有一定技术优势.%Based on the application of Ozone-Bilological Activated Carbon (O3 - BAC) in the Xiangcheng Water Treatment Plant of Suzhou, this paper analyzed and studied the practical application effects and operation requirements of this process. The results showed: based on conventional treatment, the organic removal efficiency would be improved by 20%~40%, chlorine disinfection byproducts would be reduced by 40%, and the effluent water quality was stable; O3 -BAC could handle the unexpected accidents, such as algae outbreak, and raw water quality temporal sudden deterio-ration; water temperature had a significant effects on BAC treatment, and the winter treatment was better than summer; during the operation, attention should be paid on the problems such as BAC lifetime, bromated, aqua-organism safety, and high ammonian nitrogen concentration in winter; according to the Taihu lake raw water, the O3 - BAC process had some technical advantages.

  9. Enhanced formation of disinfection byproducts in shale gas wastewater-impacted drinking water supplies.

    Science.gov (United States)

    Parker, Kimberly M; Zeng, Teng; Harkness, Jennifer; Vengosh, Avner; Mitch, William A

    2014-10-01

    The disposal and leaks of hydraulic fracturing wastewater (HFW) to the environment pose human health risks. Since HFW is typically characterized by elevated salinity, concerns have been raised whether the high bromide and iodide in HFW may promote the formation of disinfection byproducts (DBPs) and alter their speciation to more toxic brominated and iodinated analogues. This study evaluated the minimum volume percentage of two Marcellus Shale and one Fayetteville Shale HFWs diluted by fresh water collected from the Ohio and Allegheny Rivers that would generate and/or alter the formation and speciation of DBPs following chlorination, chloramination, and ozonation treatments of the blended solutions. During chlorination, dilutions as low as 0.01% HFW altered the speciation toward formation of brominated and iodinated trihalomethanes (THMs) and brominated haloacetonitriles (HANs), and dilutions as low as 0.03% increased the overall formation of both compound classes. The increase in bromide concentration associated with 0.01-0.03% contribution of Marcellus HFW (a range of 70-200 μg/L for HFW with bromide = 600 mg/L) mimics the increased bromide levels observed in western Pennsylvanian surface waters following the Marcellus Shale gas production boom. Chloramination reduced HAN and regulated THM formation; however, iodinated trihalomethane formation was observed at lower pH. For municipal wastewater-impacted river water, the presence of 0.1% HFW increased the formation of N-nitrosodimethylamine (NDMA) during chloramination, particularly for the high iodide (54 ppm) Fayetteville Shale HFW. Finally, ozonation of 0.01-0.03% HFW-impacted river water resulted in significant increases in bromate formation. The results suggest that total elimination of HFW discharge and/or installation of halide-specific removal techniques in centralized brine treatment facilities may be a better strategy to mitigate impacts on downstream drinking water treatment plants than altering

  10. Influence of different disinfecting modes on disinfection efficiency of outlet water from sand filter%不同的消毒方式对砂滤池出水消毒效果的影响

    Institute of Scientific and Technical Information of China (English)

    李芳; 陆少鸣

    2013-01-01

    Using pilot test with the mid-positioning O3-biological activated carbon filter,influences of different disinfection methods on disinfection efficiency of outlet water from sand filter were researched by the detection and analysis of microorganism,micro aquatic animals,DBPs and AOC.The results showed that the effect of chlorine disinfection was slightly weaker than ozone disinfection combined chlorination in removing microorganisms and micro aquatic animals.For the disinfection by-production of halogenated hydrocarbon and chlorate,chlorine disinfection produced more than ozone disinfection combined chlorination,the bromated is on the same level,while the formaldehyde is the opposite.The average AOC of sand filter effluent with chlorination and with ozone disinfection combined chlorination is 75.93 μg acetic acid carbon/L and 101.23 μg acetic acid carbon/L,respectively.The latter is more than 100 μg acetic acid carbon/L,which is unbeneficial for the biology stability of water distribution system.%采用中置O3-BAC工艺进行中试实验,通过对微生物、微型生物、消毒副产物和AOC进行检测分析,研究了不同的消毒方式对砂滤池出水消毒效果的影响.结果表明,氯消毒对微型生物、微生物的去除效果稍弱于臭氧联合氯消毒;对于消毒副产物而言,氯消毒产生的卤代烃、氯酸盐的含量高于臭氧联合氯消毒,产生的溴酸盐两者处于同一水平,而产生的甲醛则是氯消毒低于臭氧联合氯消毒;氯消毒最终砂滤池出水AOC平均含量75.93 μg乙酸碳/L,臭氧联合氯消毒为101.23μg乙酸碳/L,大于100 μg乙酸碳/L,不利于供水管网的生物稳定性.

  11. 冲击氯消毒控制建筑供水管道二次污染%Effect of Shock Chlorine Disinfection on Secondary Pollution in Building Water Supply System

    Institute of Scientific and Technical Information of China (English)

    王帅; 杨艳玲; 相坤; 李星; 赵锂; 陈永

    2016-01-01

    针对建筑小区的供水管道存在的生物作用等二次污染问题,研究了冲击氯消毒技术对DOC降解和硝化作用的控制效果以及对副产物溴酸盐的影响.结果表明,冲击氯消毒可有效控制DOC降解和硝化作用,生物降解作用明显减弱,可显著降低微生物超标的风险和威胁.停止冲击氯消毒后DOC降解和硝化作用逐步恢复,在冲击氯消毒后的第52 ~ 80天,DOC降解和硝化作用基本恢复到原有水平,因此有必要进行定期冲击氯消毒.冲击消毒后,BrO;浓度总体呈现增加的趋势,但在冲击氯消毒第80天后,供水管道的生物作用限制了BrO3-的生成,因此在进行冲击氯消毒时,应考虑供水管道中相关消毒副产物的变化趋势以及可能造成的化学安全性风险.%Aimed at solving the problem of secondary pollution in building water supply system,the effects of shock chlorine disinfection on dissolved organic carbon (DOC) biodegradation and biological nitrification as well as the existing bromate were investigated.The results showed that the shock chlorine disinfection was effective in controlling the DOC biodegradation and biological nitrification in the building water supply system.Meanwhile,the shock chlorine disinfection could significantly reduce the risk of bacteriological index.However,the biodegradation of DOC and biological nitrification could be restored to the original level on the 52nd to 80th day after chlorination.Therefore,the shock chlorine disinfection was required again.After shock chlorine disinfection,BrO3-concentrations showed an increase trend,and the biodegradation restricted the production of BrO3-concentration on the 80th day.Consequently,there should be paid more attention to the tendency of disinfection by-products and the risk of chemical safety during the shock chlorine disinfection.

  12. Recent advances in drinking water disinfection: successes and challenges.

    Science.gov (United States)

    Ngwenya, Nonhlanhla; Ncube, Esper J; Parsons, James

    2013-01-01

    Drinking water is the most important single source of human exposure to gastroenteric diseases, mainly as a result of the ingestion of microbial contaminated water. Waterborne microbial agents that pose a health risk to humans include enteropathogenic bacteria, viruses, and protozoa. Therefore, properly assessing whether these hazardous agents enter drinking water supplies, and if they do, whether they are disinfected adequately, are undoubtedly aspects critical to protecting public health. As new pathogens emerge, monitoring for relevant indicator microorganisms (e.g., process microbial indicators, fecal indicators, and index and model organisms) is crucial to ensuring drinking water safety. Another crucially important step to maintaining public health is implementing Water Safety Plans (WSPs), as is recommended by the current WHO Guidelines for Drinking Water Quality. Good WSPs include creating health-based targets that aim to reduce microbial risks and adverse health effects to which a population is exposed through drinking water. The use of disinfectants to inactivate microbial pathogens in drinking water has played a central role in reducing the incidence of waterborne diseases and is considered to be among the most successful interventions for preserving and promoting public health. Chlorine-based disinfectants are the most commonly used disinfectants and are cheap and easy to use. Free chlorine is an effective disinfectant for bacteria and viruses; however, it is not always effective against C. parvum and G. lamblia. Another limitation of using chlorination is that it produces disinfection by-products (DBPs), which pose potential health risks of their own. Currently, most drinking water regulations aggressively address DBP problems in public water distribution systems. The DBPs of most concern include the trihalomethanes (THMs), the haloacetic acids (HAAs), bromate, and chlorite. However, in the latest edition of the WHO Guidelines for Drinking Water Quality

  13. Development of sustainable Palladium-based catalysts for removal of persistent contaminants from drinking water

    Science.gov (United States)

    Shuai, Danmeng

    Pd-based catalytic reduction has emerged as an advanced treatment technology for drinking water decontamination, and a suite of persistent contaminants including oxyanions, N-nitrosoamines, and halogenated compounds are amenable to catalytic reduction. The primary goal of this study is to develop novel Pd-based catalysts with enhanced performance (i.e., activity, selectivity, and sustainability) to remove contaminants from drinking water. The effects of water quality (i.e., co-contaminants in water matrix), catalyst support, and catalyst metal were explored, and they provide insights for preparing catalysts with faster kinetics, higher selectivity, and extended lifetime. Azo dyes are wide-spread contaminants, and they are potentially co-exisiting with target contaminants amenable for catalytic removal. The probe azo dye methyl orange (MO) enhanced catalytic reduction kinetics of a suite of oxyanions (i.e., nitrate, nitrite, bromate, chlorate, and perchlorate) and diatrizoate significantly but not N-nitrosodimethylamine (NDMA) with a variety of Pd-based catalysts. Nitrate was selected as a probe contaminant, and several different azo dyes (i.e., (methyl orange, methyl red, fast yellow AB, metanil yellow, acid orange 7, congo red, eriochrome black T, acid red 27, acid yellow 11, and acid yellow 17) were evaluated for their ability to enhance reduction. A hydrogen atom shuttling mechanism was proposed and a kinetic model was proposed based on Bronsted-Evans-Polanyi (BEP) theory, and they suggest sorbed azo dyes and reduced hydrazo dyes shuttle hydrogen atoms to oxyanions or diatrizoate to enhance their reduction kinetics. Next, vapor-grown carbon nanofiber (CNF) supports were used to explore the effects of Pd nanoparticle size and interior versus exterior loading on nitrite reduction activity and selectivity (i.e., dinitrogen over ammonia production). In order to evaluate the amount of interior versus exterior loading of Pd nanoparticles, a fast and accurate geometric

  14. Determination of Anions in High Chloride Matrix by Ion Chromatography with Pre Online Sample Preparation Technique%谱睿在线除氯技术检测高氯水样中的阴离子

    Institute of Scientific and Technical Information of China (English)

    张夕虎; 刘肖

    2011-01-01

    We developed a method in which Dionex "Pre" online sample preparation technique was used to remove chloride by Ag cartridge and Na cartridge. This method is applicable to a wide range of samples and is simpler than offline approach. Each Ag cartridge carries on 400 consecutive injections (25 microlitre each) of 1% NaCl solution, and the removal efficiency is still above 99%. The separation of anions was carried out by high capacity hydroxide selectivity IonPac ASll-HC gradient separation column while Eluent Generator was employed to generate gradient KOH eluent online automatically. Two valves were switched to finish the injection. The system removes chloride well online for different matrix as analysis grade salt and sodium chloride. The detection limits of bromate, chlorate, chlorite, nitrite, nitrate and sulfate are less than 10μg/L, and the recoveries are between 80% and 110%. This method holds the advantages of easy-operation, good reproducibility, lower operation cost etc and is more convenient than off-line approach.%采用戴安公司谱睿(Pre)在线样品前处理技术,使用高容量在线Ag柱和Na柱,开发出了一种柱前去除高氯基体中氯离子的在线分析方法.操作简便,且适用样品范围广;不更换Ag柱可耐受10g/L NaCl基体,25μL连续进样400针,氯离子去除效率可保持在99%以上.系统选用高容量IonPac AS11-HC氢氧根体系阴离子交换色谱柱,在线淋洗液自动发生装置进行梯度淋洗,用抑制型电导检测.对食盐、分析纯氯化钠等不同基体进行检测,可实现样品在线除氯,并可检测其中不高于10μg/L的溴酸根、氯酸根、亚硝酸根、硝酸根和硫酸根等离子.不同离子校准曲线相关系数均在99.8%以上,加标回收率为80%~110%.该技术具有操作简单、可重复性强、方法新颖等特点,解决了以往高氯基体检测成本过高、适用范围有限、前处理操作复杂等问题.

  15. 紫菀的电化学指纹图谱研究%Electrochemical fingerprints of radix asteris

    Institute of Scientific and Technical Information of China (English)

    程旺兴; 陈振华; 陈佳; 程铭恩; 彭华胜; 方成武

    2012-01-01

    通过别洛索夫-扎鲍京斯基(B-Z)振荡反应研究不同产地中药紫菀鉴别的鉴别,将紫菀粉末加入H2SO4-Ce(SO4)2-CH2(COOH) 2-KBrO3中,干扰化学振荡体系,用电化学工作站记录数据,并对温度、紫菀用量等反应条件进行了考察,确定体系的最佳实验条件为12 mL(3.0 mol/L)H2SO4溶液、3 mL(0.1 mol/L)Ce(SO4)2溶液、6 mL(1.0 mol/L)CH2(COOH)2和3 mL(0.2 mol/L)KBrO3溶液,温度310 K、加入0.4g紫菀粉末,获得了不同产地紫菀的电化学指纹图谱.通过对不同产地中药材紫菀电化学指纹图谱的研究,发现不同产地的紫菀的指纹图谱主要参数有较大区别.该方法简便、准确、可靠,可方便的用于不同产地紫菀的鉴别.%The electrochemical fingerprints of radix asteris from different places have been studied by Belousov-Zhabotin-skii oscillation system. With adding power of Radix Asteris to chemical oscillation system of H2SO4-Ce ( SO4 )2-CH2-(COOH)2KBrO3 ,and the data of potential and time was recorded by the electrochemical workstation. The temperature of B-Z oscillation system,stirring speed,the added amount of radix asteris are studied also. The results showed that the optimum conditions were as follows; 12 mL 3.0 mol/L sulfuric acid,3 mL 0. 1 mol/L cerium( IV ) sulfate,6 mL 1. 0 mol/L malonic acid, 3 mL 0. 2 mol/L potassium bromate, reaction temperature 310 K,0. 4 g powder of radix asteris. The electrochemical fingerprints of radix asteris from different places showed significantly different characteristics, such as the maximum potential,induction time and oscillation lifetime,etc. So this method can be used to identify radix asteris from different origins and has the advantage of convenience, sensitivity and precision.

  16. Study on Chemical Fingerprints of Traditional Chinese Medicine Radix Paeoniae Rubra in Oscillation System%不同产地中药赤芍在振荡体系中的化学指纹图谱研究

    Institute of Scientific and Technical Information of China (English)

    程旺兴; 管艺; 陈佳; 方成武

    2011-01-01

    采用H2 SO4 - CH2 (COOH)2 - Ce2( SO4)3- KBrO3化学振荡体系,研究了中药赤芍的化学指纹图谱,并对温度、赤芍用量进行了考察,确定体系的最佳实验条件为12 mL 3.0 mol/L H2SO4溶液、6 mL 0.4 mol/LCH2( COOH)2溶液、3 mL 0.005 mol/L Ce2( SO4)3和3 mL 0.2 mol/L KBrO3溶液,温度35℃、加入0.4g的中药材粉末.通过对不同产地中药材赤芍(安徽毫州、山东菏泽、内蒙古赤峰、海拉尔)化学指纹图谱的研究,发现不同产地的中药材赤芍不仅具有明显不同的化学指纹图谱形状,而且主要参数也有很大区别.其中毫州赤芍的最高诱导时间较小(133.76 s),但振荡寿命最长(554.89 8);而海拉尔赤芍的诱导时间最长(214.t7 s),但振荡寿命最短(237.11 s).该化学指纹图谱可方便地用于不同产地中药材赤芍的区别和鉴定.%Chemical fingerprints of Radix Paeoniae Rubra( RPR) from different places of origin were studied by chemical oscillation system of H2SO4 - CH2 (COOH) 2 - Ce2 (SO4) 3 - KBrO3. Effects of various variables on the chemical oscillation system were studied. The optimal conditions were as fol lows; 12 mL 3. 0 mol/L sulfuric acid, 6 mL 0. 4 mol/L malonate, 3 mL 0. 005 mol/L cerium am monium sulfate, 3 mL 0. 2 mol/L sodium bromate and 0. 4 g RPR powder at 35 ℃. The results indi cated that, under the optimal conditions, the chemical fingerprints of RPR from different places of origin( Bozhou, Heze, Chifeng and Hailaer) showed significantly different characteristics, such as the maximum potential, induction time and oscillation lifetime, etc. The results also indicated that the RPR from Bozhou had the shortest induction time( 133. 76 s) , but the longest oscillation lifetime (554. 89 s). The RPR from Hailaer had the longest induction time(214. 17 s) , but the shortest os cillation lifetime(only 237. 11 s). The chemical fingerprints could be used to identify the origins of RPR. The method is simple, rapid and sensitive, and without

  17. PERFIL DA QUALIDADE DAS ÁGUAS DE POÇOS EM ADAMANTINA SP, BRASIL

    Directory of Open Access Journals (Sweden)

    LOURENCETTI, Josiane

    2015-11-01

    Full Text Available The increasing use of underground water sources for the supply of the water demand of the various users takes place mainly the advantages presented by this water feature, as the natural filtering, the decrease in steps of treatment and the absence of losses by evaporation. An important factor in the choice of source for abstraction is the quality of groundwater, which according to the purpose of use must meet the drinking water standards set by the Ministry of health, in order to prevent the occurrence of diseases. The objective of this work was to verify the quality of groundwater in the municipality of Adamantina-SP, through information from 37 wells granted and registered in the DAEE (Department of water and Power of PresidentePrudente, containing qualitative analysis results of the water, in the period from 2006 to 2012. The Surfer software and Excel were used in the preparation of thematic maps and graphics generation.In verifying the quality of water potability standards were adopted and organoleptic laid down in ordinance No. 2,914/2011 the Ministry of health. The results indicated values in the default limit of drinking in a well for chrome, in six wells to lead by three wells to manganese in two for the metal and, for substances and chloride bromate in a well. Has been verified as many potential sources of contamination of underground water source in the basin of Tocantins stream, requiring deeper studies and monitoring of specific points to identify point sources of contamination. A crescente utilização dos mananciais subterrâneos para o suprimento da demanda de água dos diversos usuários decorre principalmente das vantagens apresentadas por este recurso hídrico, como a filtragem natural, a diminuição nas etapas de tratamento e, a inexistência de perdas por evaporação. Um fator importante na escolha do manancial para a captação é a qualidade da água subterrânea, que de acordo com a finalidade do uso deve atender aos

  18. 宽浓度范围水碘的碱性高锰酸钾氧化光度测定方法研究%Method for the determination of broad concentration range of iodide in drinking water by spectrophotometry with alkaline potassium permanganate oxidation

    Institute of Scientific and Technical Information of China (English)

    张亚平; 黄嫣红; 林丽卿

    2009-01-01

    water. Results The linear range of the calibration curve of the new method for iodine was 0-1200 μg/L and the linear correlative coefficient was 0.9998. The detection limit for iodine was 4 μg/L. Results of 6 times repeated determination of water samples with iodine concentration of 76.6, 207.8, 560.4 μg/L showed that the relative standard deviations(RSD) were all under 1%. The recovery of standard addition for iodine added in 8 water samples of different iodide concentration levels was 97.0% (485.2/500.0) - 102.5% (102.5/100.0). Interference of hexavalent chromium(Cr~(6+)) in water was eliminated when treated with ferrous reagent. Interference of bromate (BrO_3~-) in water was eliminated when treated with potassium bromide and nitrite sodium reagent. Zero point two mg/L Cr~(6+), 0.1 mg/L BrO_3~- in water were noninterference. Conclusion This method can be easily performed with good precision and accuracy and has broad detection concentration range, which is suitable for measuring iodide in drinking water.

  19. Integrated Process of Polytetrafluoroethylene (PTFE)Hollow Fiber Membrane for Polluted Raw Water Treatment%受污染原水处理的聚四氟乙烯中空膜组合工艺

    Institute of Scientific and Technical Information of China (English)

    厉帅; 郭建宁; 范小江; 张亮; 王凌云; 张锡辉

    2014-01-01

    %,respectively;the turbidity of the effluent is below 0. 2 NTU,and the particle number in the effluent is less than 50 CNT/mL. The concentration of THMs,HAAs, bromate and formaldehyde in the effluent are below the standard limits,and the total bacterial counts and coliform counts are not detected. It can be concluded that the addition of ozone (O3/TOC=0. 6~0. 8)can mitigate membrane fouling substantially during the operation and reduce the frequency of membrane cleaning to the half;dosage of 7 ~9 mg O3/L can eliminate membrane fouling gradually without taking out the membrane,thus chemical cleaning frequencies are decreased.