1.Some chemicals in the water and their relationship to goiter in a mountain commune
Journal of Practical Medicine 2002;435(11):32-35
The study was conducted on 593 children, 325 salt samples, 60 urinary samples and 30 fresh water samples, using the descriptive epidemiological method. Ca, Na, K, Cl, Cyanide, Fl, Cu, Pb and Iode contents were quantified. The data was processed by statistic method. The results showed that Ca and Fl contents were within acceptable limit. Iode was provided sufficiently. The content of cyanide, an anti-thyroid agent, was higher than acceptable limit
Goiter
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Chemistry
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water
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epidemiology
2.Sterilizing effect and mechanism of electrolyzed water.
Zhan-dong REN ; Yu-chan ZHU ; Ye LIU ; Xiao-rong ZHOU ; Zhi-yong ZHANG
Chinese Journal of Preventive Medicine 2008;42(8):578-581
OBJECTIVETo study the sterilizing effect and mechanism of electrolyzed-oxidizing water (EOW) and electrolyzed-reductive water (ERW) for Bacillus subtilis var. niger (ATCC9372) and Escherichia coli (8099).
METHODSThe generations of EOW and ERW were made in the ion membrane electrolysis cell. The sterilization manner was the suspension quantitative germicidal test.
RESULTSThe killing rate of EOW for Bacillus subtilis var. niger was 99.59% in 30 minutes and the killing logarithm value was 2.38 log cfu/ml; the killing rate of ERW for Bacillus subtilis var. niger was 94.62% in 60 minutes and the killing logarithm value was 1.27 log cfu/ml; the killing rate of ERW for Escherichia coli was 100% in 30 minutes and the killing logarithm value was 8.26 log cfu/ml. When the available chlorine content (ACC) value in EOW was 74.90 mg/L and killing time was 30 minutes, the killing rate for Bacillus subtilis var. niger was 99.89% and the killing logarithm value was 2.67 log cfu/ml. When the ACC value was 6.82 mg/L, the killing rate for Bacillus subtilis var. niger was 83.30% and the killing logarithm value was 0. 78 log cfu/ml under the same time. When the oxidizing-reductive potential (ORP) and pH values of EOW were 1138 mV and 2.24 respectively, the killing rate for Bacillus subtilis var. niger was 99.99%. When the ORP and pH values of EOW were 883 mV and 5. 43 respectively, the killing rate of Bacillus subtilis var. niger was 99.73%. When the ORP value of ERW is -918 mV, the sterilizing rate for Bacillus subtilis var. niger was 94.62%; when the ORP value is -155 mV, the sterilizing ratio was only 40.19%.
CONCLUSIONIt indicates that the sterilizing mechanism of EOW is mainly chemical processes (ACC), while the physical factors are auxiliary. The sterilizing mechanism of ERW is physics sterilizing that the mainly factor is ORP.
Electrolysis ; Sterilization ; methods ; Water ; chemistry
3.Synergetic inactivation of microorganisms in drinking water by short-term free chlorination and subsequent monochloramination.
Xiao-Jian ZHANG ; Chao CHEN ; Yun WANG
Biomedical and Environmental Sciences 2007;20(5):373-380
OBJECTIVETo introduce synergetic inactivation of microorganisms in drinking water by short-term free chlorination for less than 15 minutes followed by monochloramination.
METHODSIndicator microorganisms such as Escherichia coli, Staphylococcus aureus, Candida albicans, and spores of Bacillus subtilis were used to assess the efficiency of sequential chlorination and free chlorination.
RESULTSThe sequential chlorination was more efficient in inactivating these microorganisms than free chlorination, indicating that synergy was provided by free chlorine and monochloramine. Ammonia addition time, temperature and pH had influences on this synergy.
CONCLUSIONSThe possible mechanism of this synergy might involve three aspects: free chlorine causing sublethal injury to microorganisms and monochloramine further inactivating them; different ability of free chlorine and monochloramine to penetrate and inactivate microorganism congeries; and higher concentration of residual chlorine in sequential chlorination than in free chlorination.
Chloramines ; chemistry ; pharmacology ; Chlorine ; chemistry ; Disinfection ; methods ; Halogenation ; Water ; chemistry ; Water Microbiology ; Water Purification ; methods
4.Comparison of conductivity-water content curve and visual methods for ascertaintation of the critical water content of O/W microemulsions formation.
Da-wei XIANG ; Tian-tian TANG ; Jin-fei PENG ; Lan-lin LI ; Xiao-bo SUN ; Da-xiong XIANG
Acta Pharmaceutica Sinica 2010;45(8):1052-1056
This study is to screen 23 blank O/W type microemulsion (ME) samples, that is 15 samples from our laboratory, and 8 samples from literature; compare the conductivity-water content curve (CWCC) method and visual method in determining the critical water content during O/W type MEs' formation, to analyze the deficiency and the feasibility of visual method and to exploxe scientific meanings of CWCC method in judging the critical water content of O/W type MEs during formation. The results show that there is a significant difference between the theoretical feasible CWCC method and visual method in determining the critical water content (P<0.001), and the results judged by conductivity is higher than that by eye-based water content. Therefore, this article firmly confirmed the shortcomings of visual method and suggested that the eye-base "critical water content" may falls into continuous ME stage during O/W MEs' formation. Further more, the CWCC method has theoretical feasibility and scientific meanings in determining the critical water content of O/W type MEs during formation.
Electric Conductivity
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Emulsions
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chemistry
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Water
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chemistry
5.Water-soluble chemical constituents from fruits of Phellodendron chinense var. glabriusculum.
Chen YAN ; Ye WANG ; Xiaojiang HAO
China Journal of Chinese Materia Medica 2009;34(22):2895-2897
OBJECTIVETo study the water-soluble chemical constituents from the fruits of Phellodendron chinense var. glabriusculum.
METHODChemical constituents were purified by chromatographic methods and identified by spectroscopic analysis.
RESULTEight known compounds were obtained, whose structures were elucidated as sinapyl 9-O-beta-D-glucopyranoside (1), betulalbuside A (2), arbutin (3), adenosine (4), 3,5-dihydroxyphenethyl alcohol 3-O-beta-D-glucopyranoside (5), orcinol-3-O-beta-D-glucopyranoside (6), N-trans-p-coumaroyloctopamine (7), berberine (8) respectively.
CONCLUSIONCompounds 1-7 were obtained from Phellodendron chinense var. glabriusculum for the first time.
Fruit ; chemistry ; Phellodendron ; chemistry ; Plant Extracts ; chemistry ; Solubility ; Water ; chemistry
6.Water-soluble chemical constituents from Elaeagnus pungens leaves.
Mengshun LI ; Maochuan LIAO ; Yuebin GE ; Zhinan MEI
China Journal of Chinese Materia Medica 2012;37(9):1224-1226
OBJECTIVETo study water-soluble chemical constituents from the leaves of Elaeagnus pungens.
METHODChemical constituents of E. pungens leaves were separated by a combination of macroporous resin column chromatography, reverse phase silica gel column chromatography, Sephadex LH-20 column chromatography and semi-preparative HPLC. Their structures were identified on the basis of physicochemical properties using the spectral method.
RESULTThe two compounds were separated from E. pungens leaves and identified as kaempferol 3-O-P-D-glucopyranosyl- (1-->3)-alpha-L-rhamn-opyranosyl-(1-->6) -/3-D-galactopyranoside (1), kaempferol 3-O-P-D-glucopyranosyl-(1-->3)-alpha-L-rhamnopyranosyl-(1-->6)-beta-D-glucopyranoside-7-O-beta-D-glucopyranoside (2).
CONCLUSIONCompound 2 separated from E. pungens leaves was a new compound.
Elaeagnaceae ; chemistry ; Glucosides ; chemistry ; Plant Leaves ; chemistry ; Solubility ; Water ; chemistry
7.Measurement and amendment of complex-permittivities of distilled water and NaCl solution.
Yue GAO ; Guosheng YANG ; Hua WANG ; Jianqi WANG ; Shipei CHEN
Journal of Biomedical Engineering 2005;22(3):548-549
In this experiment, the complex-permittivities at 2 450 MHz of distilled water and various NaCl solutions were measured separately, and acquired data were analyzed and amended. The system develooped on the basis of this experiment is of great significance to studying the measurement of complex-permittivities of high-loss biologic tissues by perturbational method.
Chemistry Techniques, Analytical
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Sodium Chloride
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chemistry
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Solutions
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Water
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chemistry
8.Simultaneous control of microorganisms and disinfection by-products by sequential chlorination.
Chao CHEN ; Xiao-Jian ZHANG ; Wen-Jie HE ; Hong-Da HAN
Biomedical and Environmental Sciences 2007;20(2):119-125
OBJECTIVETo introduce a new sequential chlorination disinfection process in which short-term free chlorine and chloramine are sequentially added.
METHODSPilot tests of this sequential chlorination were carried out in a drinking water plant.
RESULTSThe sequential chlorination disinfection process had the same or better efficiency on microbe (including virus) inactivation compared with the free chlorine disinfection process. There seemed to be some synergetic disinfection effect between free chlorine and monochloramine because they attacked different targets. The sequential chlorination disinfection process resulted in 35.7%-77.0% TTHM formation and 36.6%-54.8% THAA5 formation less than the free chlorination process. The poorer the water quality was, the more advantage the sequential chlorination disinfection had over the free chlorination.
CONCLUSIONThis process takes advantages of free chlorine's quick inactivation of microorganisms and chloramine's low disinfection by-product (DBP) yield and long-term residual effect, allowing simultaneous control of microbes and DBPs in an effective and economic way.
Bacteria ; drug effects ; Chloramines ; chemistry ; Chlorine ; chemistry ; Disinfection ; methods ; Viruses ; drug effects ; Water ; chemistry ; Water Microbiology ; Water Purification ; methods
9.Reductive dechlorination of p-chlorophenol by nanoscale iron.
Rong CHENG ; Jian-Long WANG ; Wei-Xian ZHANG
Biomedical and Environmental Sciences 2007;20(5):410-413
OBJECTIVETo investigate reductive dechlorination of 4-chlorophenol (4-CP) by nanoscale Fe0 under different conditions.
METHODSNanoscale Fe0 was synthesized by using reductive method. 4-CP and its intermediate products were analyzed by HPLC. Chlorine ion was quantified with DX-100 ion chromatograph. Nano-iron particles were observed under a FEI Quanta 200 FEG environmental scanning electron microscope (ESEM).
RESULTSThe size of the particles was in the range of 10-100 nm. The nano-iron particles could reduce 4-CP effectively. The initial concentration of 4-CP increased with the decrease of the relative degradation rate, whereas the reduced amount of 4-CP increased. Temperature could influence both the dechlorination rate and the reaction pathway. Moreover, the stability and durability of nanoscale Fe0 was evaluated through batch studies over extended periods of time.
CONCLUSIONThe nanoscale Fe0 can be used for sustainable treatment of contaminants in groundwater.
Chlorine ; chemistry ; Chlorophenols ; chemistry ; Iron ; chemistry ; Nanoparticles ; chemistry ; ultrastructure ; Temperature ; Water Pollutants, Chemical ; chemistry
10.Kinetics of ozonation of typical sulfonamides in water.
MingHao SUI ; Sichu XING ; ChunYan ZHU ; Li SHENG ; KeXiang LU ; NaiYun GAO
Biomedical and Environmental Sciences 2011;24(3):255-260
OBJECTIVETo investigate the kinetic rate constants ozone and hydroxyl radicals towards two groups of antimicrobials -sulfadiazine (SD) and sulfamethoxazole (SMX).
METHODSThe solute consumption method was used to detect the rate constants of ozone alone with sulfadiazine and sulfamethoxazole, and tertiary butanol was selected as a scavenging agent and pH was adjusted to 2.5 by adding orthophosphate buffers (OB); and the competition kinetics studying methodwith nitrobenzene as a reference was applied to measure the rate constants of hydroxyl radicals towards sulfadiazine and sulfamethoxazole, and pH was adjusted to 7.0 by adding OB.
RESULTSThe rate constants of SD and SMX with ozone alone were 261 mol(-1) · dm(3) · s(-1) and 303 mol(-1) · dm3 · s(-1) by calculating in low reaction system. The rate constants of hydroxyl radicals with SD and SMX were 2.2×1010 mol(-1) · dm(3) · s(-1) and 2.7×1010 mol(-1) · dm(3) · s(-1), respectively. Moreover, the rate constants of hydroxyl radicals with SMX were found to have increased from 3.6×109 mol(-1) · dm(3) · s(-1) to 2.8×1010 mol(-1) · dm(3) · s(-1) with pH value rising from 5.0 to 7.8.
CONCLUSIONSMX and SD are both refractory to ozone oxidation alone, and are liable to be degraded by hydroxyl radicals, and the rate constants of SMX with the hydroxyl radical slightly increases with pH rise.
Hydroxyl Radical ; chemistry ; Kinetics ; Ozone ; chemistry ; Sulfamethoxazole ; chemistry ; Sulfonamides ; chemistry ; Water ; chemistry