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ABSTRACT: Comparative study on the activity and kinectic properties of acid phosphatase (ACPase) of three soils amended with Hg and
Cu at constant temperature and humidity was carried out. The results indicated that the inhibition on ACPase of the three
sample soils by Hg and Cu varied with the content of soil organic matter and pH, where, Soil 1 was the most seriously contaminated
due to its lowest content of organic matter and the lowest pH among three samples, Soil 2 took the second place, and Soil
3 was the least contaminated. Except Soil 3, the activity of soil ACPase tended to increase along with the contact time under
the same type and the same concentration of heavy metal. In particular the V
max values of ACPase in all three samples decreased with increasing Hg and Cu concentration, whereas the K
m values were affected weakly. According to the change of V
max and K
m values, Cu and Hg had the same inhibition effect on soil ACPase. Both of them may be a type of compound of non-competitive
and anti-competitive inhibition. Statistic analyses indicated that activities of soil ACPase and V
max values could serve as bioindicator to partially denote the heavy metal Hg and Cu contamination degree.
Journal of Zhejiang University - Science A: Applied Physics & Engineering 04/2012; 8(7):1157-1163. · 0.41 Impact Factor
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ABSTRACT: Twenty-three surface sediment samples were collected from Jiaojiang Estuary, East China Sea in order to assess the distribution, possible sources, and potential risk of polychlorinated biphenyls (PCBs) in the environment. Total concentrations of PCBs ranged from 4.93 to 108.79 ng g(-1) dry weight for all sampling stations, with a substantial higher concentration in the inner part of the estuary than the outer part of the estuary. PCB patterns in sediments from sites 1-8 were extremely dominated by tetra-PCBs, which probably due to the discharge of local industrial plants but not the expected input from the nearby e-waste recycling areas. Principal component analysis revealed that the sources of PCBs for sites 9-23 were associated with Aroclor 1248 or Aroclor 1221. However, physical migration and bio-degradation may also play a role on PCB distribution. Hazard assessment of PCBs indicated possible toxic potential, particularly in areas close to point sources.
Marine pollution bulletin 03/2012; 64(3):539-45. · 2.63 Impact Factor
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ABSTRACT: The enantioselective interaction between penicillium expansum alkaline lipase and chiral phenoxypropionic acid herbicide dichlorprop was studied by using UV differential spectrophotometry and fluorescence spectrophotometry in the presence of a pH 8, phosphate buffer solution. Chiral differences in the UV absorption and fluorescence spectra of lipase with dichlorprop were detected. (R)-Dichlorprop interacted the strongest with lipase as measured by both UV absorption and fluorescence spectrophotometry, followed by (Rac)-dichlorprop, while (S)-dichlorprop had the weakest interaction. The hydrophobic interaction seem to play the dominant role in the interactions and the (R)-enantiomer needed the minimum put of energy to drive the endothermic reaction, while the Rac-type and S-type compounds needed more for the reaction to take place. In the meantime, the catalytic hydrolysis of FDA with lipase show that (R)-DCPP could inhibit lipase the most strongly relatively at the same condition, perhaps because (R)-DCPP had a stronger combining effect and high enantiomeric selectivity on lipase than (Rac)-DCPP and (S)-DCPP.
Chirality 07/2008; 21(3):396-401. · 2.35 Impact Factor
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ABSTRACT: There exists a close relationship between plants and chiral compounds. On one hand, plants can secrete and synthesize some chiral compounds such as glucosides, enzymes, terpenoids, organic acids and phytohormones that play important roles in plant physiological and biochemical processes, and on the other hand, artificial synthetic chiral compounds, especially pesticides, had enantioselective interactions with plants. The pesticides can enantioselectively inhibit the growth of plants, or can be enantioselectively absorbed and metabolized by plants. Therefore, in the exploitation, production and application of chiral compounds, it's needed to consider the enantioselective interaction between plants and chiral compounds. In the meanwhile, choosing appropriate plants to ameliorate the environment polluted by chiral compounds is of practical significance. In this review, the enantioselective interaction between plants and chiral compounds was summarized, and the amelioration of chiral compounds-polluted environment by plants was prospected.
Ying yong sheng tai xue bao = The journal of applied ecology / Zhongguo sheng tai xue xue hui, Zhongguo ke xue yuan Shenyang ying yong sheng tai yan jiu suo zhu ban 03/2008; 19(2):441-8.
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ABSTRACT: The supramolecular complexes of fenoxaprop-p-ethyl and various cyclodextrins (beta-CD, HP-beta-CD, RAMEB) were studied by UV spectra technique. The results showed that all cyclodextrins could form 1:1 inclusion complexes with fenoxaprop-p-ethyl in ethanol-water (the volume ratio of ethanol to water was 1 : 4), and the binding constants of the three types of cyclodextrins toward fenoxaprop-p-ethyl were in the order of KRAEB>KHP-beta-CD>Kbeta-CD. Between 298. 15 and 318. 15 K, the binding constants decreased with temperature increasing. The Gibbs free energy deltaG, enthalpy change deltaH, and entropy change deltaS determined were all negative, suggesting that the inclusion complexation is exothermic and can spontaneously occur by the balance of enthalpy driving and entropy opposing.
Guang pu xue yu guang pu fen xi = Guang pu 01/2007; 26(12):2298-301. · 0.84 Impact Factor
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ABSTRACT: The enantiomers of napropamide were separated by normal phase HPLC (HPLC: high performance liquid Chromatography) with Chiralpak OJ-H column and charactered by circular dichroism. On this basis, a method for the chiral separation and micro-determination of napropamide in water was established. The linearity of calibration curve for racemic mixture was 10-100 ng x mL(-1) and the correlation coefficient was 0. 99. When 10 microL was injected, the detection limit of racemic mixture was 8 ng mL(-1), and the detection limits of both enantiomers were 4 ng x mL(-1).
Guang pu xue yu guang pu fen xi = Guang pu 10/2006; 26(9):1649-52. · 0.84 Impact Factor
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ABSTRACT: Cyclodextrins (CDs), with hydrophobic interior cavity and hydrophilic external surface, are capable of accelerating or inhibiting chemical degradation of organophosphorus pesticides through forming inclusion complexes between CDs and pesticides. This work evaluated the effects of CDs on hydrolysis of malathion in an attempt to assess their potential application in environmental approach. beta-CD and its two derivatives, randomly methylated beta-CD (RAMEB) and hydroxypropyl beta-CD (HP-beta-CD), were tested. It was found that RAMEB could inhibit the hydrolysis of malathion, and this was the function of pH and temperature, the inhibitory effects increase with increasing concentration of RAMEB and elevating temperature between 15 and 35 degrees C. On the other hand, beta-CD and HP-beta-CD have little or no stabilizing effects on malathion at all pH and temperature studied, except that the large concentration of beta-CD and HP-beta-CD can mildly reduce hydrolysis of malathion. Both 2 mol/L and 5 mol/L urea increase the inhibitory effects of RAMEB on hydrolysis of malathion at 25 degrees C, pH 9.0.
Journal of Environmental Sciences 02/2006; 18(3):572-6. · 1.66 Impact Factor
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ABSTRACT: The experiments indicated that terbium(III) ion could complex ciprofloxacin, then emitted the characteristic fluorescence of terbium(III) ion. When the surfactant of SDBS was added, the fluorescence intensity of the system was greatly increased. From this, a sensitive method of determining the ciprofloxacin was developted. The fluorescence intensity was determined by a 1 cm quartz cell with the excitation wavelength of 300 nm and the emission wavelength of 545 nm. The optimal conditions are as follows: pH 8.0-8.5, the concentration of terbium(III) is 5.0 x 10(-5) mol x L(-1), the surfactant concentration of SDBS is 8.0 x 10(-4) mol x L(-1). The linear range is 2.5 x 10(-6) mol x L(-1) -2.0 x 10(-8) mol x L(-1), and the detection limit (S/N = 3) is 4.0 x 10(-9) mol x L(-1). The presented method was applied to determine the real pharmaceuticals of ciprofloxacin.
Guang pu xue yu guang pu fen xi = Guang pu 01/2006; 25(12):2061-4. · 0.84 Impact Factor
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ABSTRACT: The effect of kaolinite on the enzymatic chiral hydrolysis of methyl dichlorprop enantiomers ((R,S)-methyl-2-(2,4- dichlorophenoxy) propanoic acid, 2,4-DPM) was investigated using chiral gas chromatography. Compared with the control without kaolinite, the enantiomeric ratio (ER) increased from 1.35 to 8.33 and the residual ratio of 2,4-DPM decreased from 60.89% to 41.55% in the presence of kaolinite. Kaolinite likely had emotion influence on lipase activity and its enantioselectivity. Moreover, the amount of kaolinite added was also found to be a sensitive factor affecting the enantioselective hydrolysis of 2,4-DPM. Fourier transform infrared (FTIR) spectroscopy studies of the interaction of lipase with kaolinite provided insight into the molecular structure of the complex and offered explanation of the effects of kaolinite on enzymatic hydrolysis of 2,4-DPM. Spectra showed that the effect of kaolinite on the hydrolysis of 2,4-DPM was affected by adsorption of lipase on kaolinite and changes of adsorbed lipase conformation, which led to the modified enantioselectivity.
Journal of Zhejiang University SCIENCE B 11/2005; 6(10):1028-32. · 1.10 Impact Factor
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ABSTRACT: Enantioselective Degradation of 2,4-Dichlorprop methyl ester was studied by sediment bacteria. One DCPPM-degrading bacteria stain was isolated from contaminated sediments. The EF values were determined by chiral GC. The enantioselectivity of DCPPM biodegradation in aquatic phases were evaluated. Incubation with DCPPM-degrading bacteria show that the R enantiomer was preferentially degraded over the corresponding S enantiomer of DCPPM. The EF values show a much higher deviation. It indicate that the microbial degradation of DCPPM was enantioselectivety.
Huan jing ke xue= Huanjing kexue / [bian ji, Zhongguo ke xue yuan huan jing ke xue wei yuan hui "Huan jing ke xue" bian ji wei yuan hui.] 08/2005; 26(4):152-5.
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ABSTRACT: Chemical oxygen demand (COD) removal rates of sulfosalicylic acid (SSal) degraded by three advanced oxidation processes (AOPs): O3/UV, O3/TiO2/UV and O3/V-O/TiO2 are compared in this paper. (V = Vanadium). The results show that O3/V-O/TiO2 is the most effective process among three AOPs and the order of degradation efficiencies at different pH values is shown as O3/V-O/TiO2 > O3/TiO2/UV > O3/UV. For example, at the buffered solution of pH 6.8, the COD removal rate of O3/V-O/TiO2 reaches 70% in 30 minutes, but those of O3/TiO2/UV and O3/UV are 55% and 47% at the same conditions, respectively. Furthermore, the effect of CO3 2 −on the COD removal rates of three AOPs shows that O3/V-O/TiO2 and O3/TiO2/UV may be considerable promising methods to overcome the limitation of the presence of radical scavenger in solution. Both the adsorption of SSal on catalysts and other oxidants (atom oxygen, photo-generated hole) must be responsible for the above result.
Ozone: Science and Engineering. 06/2005; 27(3):233-238.
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ABSTRACT: Experiments indicated that cerium(IV) ion which could not emit fluorescence was deoxidized by ascorbic acid to cerium(III) ion which could emit its characteristic fluorescence in water solution, while sodium hexametaphosphate added could greatly enhance the fluorescence intensity of the system. From this, an indirect sensitive method for determining ascorbic acid was developed. The fluorescence intensity of the system was measured in a 1 cm quartz cell with the excitation and emission wavelengths of 303 and 340 nm, respectively. The results showed that the fluorescence intensity of the system presented a linear relationship with the concentration of ascorbic acid in the range of 1.0 x 10(-7)-8.0 x 10(-6) mol x L(-1), the correlation coefficient r was 0.9997, and the detection limit (S/N = 3) was 1.6 x 10(-8) mol x L(-1). The presented method was used to determine ascorbic acid sample and vitamin C tablet, and the results were satisfactory.
Guang pu xue yu guang pu fen xi = Guang pu 05/2005; 25(4):598-600. · 0.84 Impact Factor
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ABSTRACT: The relationship between excess thermodynamic function and binding to urease of four chloroacetanilide herbicides was studied using high-performance liquid chromatography and fluorescence spectrum. The linear relationship between the composition of mobile phase of RP-HPLC and the capacity factor of chloroacetanilide herbicides has been obtained. The excess thermodynamic enthalpy (deltaH* ) of acetochlor, pretilachlor, butachlor and metolachlor was determined, and the binding constant K and the number of binding sites with urease were calculated. The relationship between excess thermodynamic function and the binding constant K was suggested.
Guang pu xue yu guang pu fen xi = Guang pu 04/2005; 25(3):463-6. · 0.84 Impact Factor
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ABSTRACT: Degradation of organic contaminants in water by high-voltage pulse discharges was investigated. The effects of gas flow rate and liquid conductivity on the degradation of 4-chlorophenol were studied. With the increase of time, the liquid conductivity increases, which have an important effect on discharge. Meanwhile, with the increase of time, the concentration of H2O2 increases. Addition of 200 mg/L H2O2, the conversion of 4-chlorophenol was greatly enhanced. This may be due to the synergistic effect of high-voltage pulsed discharge and H2O2. Also, it was found that the influence of quantity of TiO2or CuO on degradation of acetophenone is not apparent, maybe the presence of metal oxides hinders the formation of plasma channel due to increase of collusions between metal oxides and oxygen.
Plasma Chemistry and Plasma Processing 03/2005; 25(2):137-146. · 1.60 Impact Factor
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ABSTRACT: Reactive Red 195, which is an azoic anionic dye characterized by the presence of five sulfonic groups and one azoic group, is efficiently removed using chitosan. The increasing chitosan dose had a dramatic positive impact on the achieved color removal, there was approximately a linear relationship between chitosan dose and color removal of dye before color removal reach maximum. Also, the increase of dye concentration led to the increase of chitosan dosage in order to get the same color removal. 92 mg/L of chitosan dosage was sufficient to achieve complete remove of dye at initial concentration of dye at 200 mg/L. For the higher concentrations of dye, high dosages were necessary to reach complete color removal. On the other hand, the use of adsorption interferents (Fe2+, Na+, HCO3- and others) can be interesting, addition of ions had effect on the color removal of Reactive Red 195. Comparing with blank, addition of chemical species approximately decreased the color removal except Na+ and combination of Fe2+ + HCO3-. However, comparing with Fe2+ alone and HCO3- alone, combination of Fe2+ + HCO3- increased the color removal.
Journal of Environmental Sciences 02/2005; 17(5):766-9. · 1.66 Impact Factor
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ABSTRACT: The effect of beta-cyclodextrins (beta-CDs) on the enzymatical hydrolysis of chiral dichlorprop methyl ester (DCPPM) was studied. Four kinds of beta-cyclodextrins (beta-cyclodextrin, Partly methylated-CD (PM-beta-CD), hydroxypropyl-cyclodextrin (HP-beta-CD) and carboxymethyl-cyclodextrin (CM-beta-CD)) were used. Compared with 100% DCPPM in the absence of betacyclodextrins, the activity of lipase decreased with the increase of Pbetacyclodextrin and PM-Pbetacyclodextrin. However, CM-beta-clodextrin stimulated the lipase activity. The inhibition effect of Pbeta cyclodextrin and PM-5betacyclodextrin on the hydrolysis of DCPPM is affected by many factors other than degree of the methylation blocking the active site of lipase. UV-Vis and Fourier transform infrared (FTIR) spectroscopy studies of the complexation of aqueous DCPPM with beta-CDs provide fresh insight into the molecular structure of the complex and explain the effects of beta-CDs on enzymatical hydrolysis of chiral DCPPM. Data showed that inclusion complexes had formed by complexation of the CM-beta-CD with DCPPM and the solubility of DCPPM was increased in water, which lead to the increased lipase activity.
Journal of Environmental Sciences 02/2005; 17(2):237-40. · 1.66 Impact Factor
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ABSTRACT: Through cation-exchanging of montmorillonite, mixed hydroxy Fe-Al-pillared montmorillonites with large basal spacing were synthesized. The application of these mixed hydroxy Fe-Al-pillared montmorillonites as adsorbents in the areas of environmental protection and pollution control was investigated. Adsorption of Direct Green B, an organic dye, on OH--Fe--, OH--Al--, OH--Fe--Al-- pillared montmorillonites was studied. Results showed that these pillared montmorillonites had much better adsorption properties than traditional Na-organo-montmorillonite. It was also found that pH of the solutions had great effect on the performance of these hydroxy-metal pillared montmorillonites in treating the wastewater containing Direct Green B.
Journal of Environmental Sciences 02/2005; 17(1):159-62. · 1.66 Impact Factor
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ABSTRACT: Hydrolytic degradation of the herbicide diclofop-methyl was investigated in the multi-pH deionized water, natural aquatic systems and soil suspensions. Resulting data indicated that the herbicide was stable in the acidic and nearly neutral solutions for at least 15 d. The herbicide diclofop-methyl rapidly dissipated in the natural aquatic systems and soil suspensions with half-lives less than 4 d. Methyl-CD (partially methylated beta-cyclodextrin) improved its hydrolytic degradation in the pH 8 deionized water and natural aquatic systems while humic acid inhibited its hydrolytic degradation at the same conditions. But dissolved organic matter in the natural aquatic systems and soil suspensions increased its hydrolysis. Two catalysis mechanisms were introduced to describe the effects of cyclodextrin and organic matter on its hydrolytic metabolism. Though inorganic ions maybe improved its hydrolysis reaction in the natural aquatic systems, Fe2+ and Cu2+ did not form complexes with the herbicide and had poor influences on its hydrolytic degradation whether cyclodextrin was added or not.
Journal of Environmental Sciences 02/2005; 17(1):67-71. · 1.66 Impact Factor
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ABSTRACT: Conformational and activity changes of acid phosphatase from wheat germ in ethanol solutions of different concentrations were measured by fluorescence spectra and differential UV-absorption spectra. The effect of ethanol on kinetics of acid phosphatase was determined by using the double reciprocal plot. The results indicate the ethanol has a significant effect on the activity and conformation of acid phosphatase. The activity of acid phosphatase decreased linearly with increasing the concentration of ethanol. Differential UV-absorption spectra of the enzyme denatured in ethanol solutions showed two positive peaks at 213 and 234 nm, respectively. The peaks on the differential UV-absorption spectra suggested that the conformation of enzyme molecule changed from orderly structure to out-of-order crispation. The fluorescence emission peak intensity of the enzyme gradually strengthened with increasing ethanol concentration, which is in concordance with the conformational change of the microenvironments of tyrosine and tryptophan residues. The results indicate that the expression of the enzyme activity correlates with the stability and integrity of the enzyme conformation to a great degree. Ethanol is uncompetitive inhibitor of acid phosphatase.
Guang pu xue yu guang pu fen xi = Guang pu 12/2004; 24(11):1388-90. · 0.84 Impact Factor
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ABSTRACT: Environmental concerns have highlighted the need of cleaner technologies. A cleaner, convenient and selective technology has been developed for the preparation of 3-(4,6-dimethoxy-pyrimidin-2-yloxy)-2-methyl-phenol (DPMP) from 2-methyl-benzene-1,3-diol in water as solvent. The isolated yield of DPMP is up to 86% in good selectivity. The product structure was characterized by conventional methods, 1H-NMR and MS. This technology belongs to the modern concept of environmentally friendly low wastes or non-wastes technology (LWNWT).
Journal of Zhejiang University SCIENCE 09/2004; 5(8):956-9.
