[Operation-effect analysis of 21 patients with ankle fracture and complete rupture of deltoid ligament].

OBJECTIVE: To explore short-term clinical effect of surgical treatment for ankle fracture with complete rupture of deltoid ligament in young and middle-aged patients. METHODS: From January 2016 to March 2019, 21 young and middle-aged patients with ankle joint fracture and complete rupture of the deltoid ligament were treated with internal fixation and repair of the medial deltoid ligament, including 16 males and 5 females, aged from 21 to 52 years old with an average of (38.6±7.3) years old, the time from injury to operation ranged from 1 to 7 days with an average of (3.8±1.5) days. Fracture healing time and complications were observed, changes of medial malleolus clearance before and after operation were compared, American Orthopaedic Foot and Ankle Society (AOFAS) score wasused to evaluate function of ankle joint at 18 months after operation. RESULTS: Twenty-one patients were followed up from 18 to 26 months with an average of (21.7±1.2) months. The incisions were healed at stageⅠ, and fracture healing time ranged from 8 to 12 weeks with an average of (9.5±1.6) weeks. No wound infection, failure of internal fixation, and nerve injury occurred. Medial malleoius space decreased from (5.83±0.32) mm before operation to (2.69±0.25) mm after operation. Postoperative AOFAS score at 18 months was 91.43±4.14, 14 patients got excellent results, 6 good and 1 fair. CONCLUSION: On the basis of stable fixation of fracture, repair of deltoid ligament could help restoring the medial anatomy of ankle joint in young and middle-aged patients, and could achieve good short term clinical effect.

[Classification and Analysis of Dissolved Organic Matter in 2-Buternal Manufacture Wastewater].

The dissolved organic matters from 2-buternal manufacture wastewater were fractionated into seven fractions by ultra-filtration membrane separation. The amounts and structural compositions of organic compounds in different molecular weight ranges were characterized by dissolved organic carbon (DOC), ultraviolet spectrum (UV), Fourier transform infrared spectrometer (FT-IR) and gas chromatography with mass spectrometry (GC-MS). The results showed that the fraction of molecular weight less than 1×103 had the largest proportion in the wastewater, and occupied 88.57% of the DOC. There were 27 kinds of compounds qualitatively analyzed by GC-MS, mainly including aldehyde, ketone, ester, alcohol, phenol, organic acid, alkane and other heterocyclic compounds. The proportions of compounds of peak area accounting for total peak area of organic matters were 6.9%, 5.3%, 35.4%, 13.2%, 4.6%, 0.4%, 1.7% and 16.8% respectively, adding up to 84%. The analysis of UV and FT-IR demonstrated that the spectral absorptive characteristics of organic compounds from different fractions were not significantly different. The fractions contained carbonyls, hydroxys and aromatic compounds, which was consistent with the qualitative analysis of GC-MS. The results of this study provide an important guidance for the development and optimization of 2-buternal manufacture wastewater treatment process.

[The Study on the Characteristics of Organic Pollution in Typical Herbicide Plant Wastewater].

Herbicide wastewater is one of tne industrial wastewater, it has high salt content, poor biodegradability, biodegradable characteristics. Nitrogen-containing organic compounds are dominated in dissolved organic matter and dissolved organic matter of wastewater, BOD: COD = 0.045, C:N:P = 692:426:1. Applying static headspace, purg and trap, solid-phase extraction, solid-phase microextraction and liquid-liquid extraction as pretreatment methods combined with gas chromatography/mass spectrometry (GC/MS), which qualitatively analyzed the organic components of the Atrazine, acetochlor herbicide production wastewater and researched the UV spectrum, three-dimensional fluorescence spectroscopy of the wastewater and its major pollutants. The study of GC/MS indicated that Wastewater contained chlorinated hydrocarbons, BTEX and triazines, amides herbicides etc. 38 kinds of volatile and semi-volatile organic compounds, atrazine and acetochlor herbicides accounted for 87. 99%. Affected monocyclic or heterocyclic substances, the ultraviolet absorption spectrum of the wastewater in 210-230 and 250-270 nm in that the amino group lead to the UV absorption red shift 20 nm. Wastewater generated 5 fluorescence peak in λ(ex)/λ(em) = 200-280/300-400 nm, such as a(225/305 nm), b(265/365 nm), c(275/305 nm), d(285/390 nm), e(320/375 nm). Based on three-dimensional fluorescence results of the different functional groups of the characteristics organic, fluorescent area of unsaturated bond is in λ(ex)/λ(em) = 215-230/290-340 nm, the main contribution of the fluorescent substance in the region were olefins, benzene, heterocyclic in the wastewater; fluorescent area of Phenolic hydroxyl and carbonyl is in λ(ex)/λ(em) = 270/300 nm, the main contribution of the fluorescent substance in the region were phenols, ketones.

[Variation characteristics and removal rate of fluorescence organic matter in the petrochemical wastewater treatment process].

Petrochemical wastewater is of huge quantity released during the production and complicated contaminants of petrochemical wastewater will have immense negative impact on ecology environment. Three-dimensional excitation-emission matrix fluorescence(3D-EEM) was used to investigate the characteristic fluorescence of influent and effluent from each processing unit of Hydrolysis-acidification +A/O+ Contact-oxidation Process in a typical petrochemical wastewater treatment plant . The results showed that there were 4 fluorescence peaks named Peak A, Peak B, Peak D, Peak E in the spectrum chart of influent, they are around lambda(ex/lambda(em) = 220/300, 225/340, 270/300, 275/340 nm, the primary source of fluorescence organic matter(FOM) is industrial wastewater. The fluorescence intensity of each fluorescence peak was decreased, while location was unchanged in the effluent of Hydrolysis-acidification. Peak C appeared from the effluent of anaerobic tank at lambda(ex)/lambda(em) = 250/425 nm, then the fluorescence intensity of Peak C was enhanced in the effluent of aerobic tank. Peak A disappeared from the effluent of secondary sedimentation tank. The spectrum chart of the wastewater had no obvious variation after secondary sedimentation tank. The removal rate of FOM was expressed with the degradation percentage of the fluorescence intensity, the total FOM was reduced by 92.0% after processing, and the removal rate of the FOM fluoresce around Peak A, Peak B, Peak D, Peak E were 100.0%, 91.2%, 80.3%, 92.0% respectively. A volatile I(Peak B)/I(Peak E) value of influent but a relatively stable value of effluent demonstrated that the wastewater treatment plant operated steadily and the process has higher capacity in resistance to shock loading.

[A method for determination of trace naphthalene and phenanthrene in water using constant-wavelength synchronous fluorescence spectrometry].

In view of synchronous fluorescence possessing the character of good selectivity, high sensitivity, less interference, etc. it can be used for simultaneous determination of multi-component mixtures of polycyclic aromatic hydrocarbons (PAHs). A new method of constant-wavelength synchronous fluorescence spectrometry to determine two naphthalene and phenanthrene of PAHs was developed in this study. The effect of different experimental conditions, such as different disolvents for character of fluorescence spectra and the choose of the optimal wavelength difference were studied. Experiment showed that the simultaneous indentification and quantitative determination of the two PAHs when delta lambda = 100 was chosen. The fluorescence intensity was linearly related to naphthalene and phenanthrene concentration in the range of 0.5-25.0 microg x L(-1) with correlation coefficient 0.999 5 and 0.999 7, respectively. The detection limits were all lower than 0.03 microg x L(-1), and the relative standard deviations for naphthalene and phenanthrene were 1.19% and 180% (n=7), respectively. Results show that the compounds can be analyzed qualitatively and quantitatively by synchronous fluorescence spectrometry.

[The qualitative analysis method of the dissolved organic matter (DOM) for ABS wastewater].

The dissolved organic matter (DOM) of acrylonitrile-butadiene-styrene (ABS) resin wastewater was qualitatively analysed by gas chromatography with mass spectrometry(GC-MS), Fourier transform infrared spectrometer(FTIR) and three-dimensional excitation-emission matrix (EEM) fluorescence spectroscopy. The detected results shows that the GC-MS qualitatively analysed 21 dissolved organic pollutants, such as acetophenone, styrene, alpha, alpha-dimethyl-benzenemethanol, 3,3'oxybis-propanenitrile, 3, 3'-iminobis-propanenitrile, 3,3'-thiobis-propanenitrile, 3-(dimethylamino)-propanenitrile and 2-propenenitrile. The results of Fourier transform infrared spectrometer (FTIR) and three-dimensional excitation-emission matrix (EEM) fluorescence spectroscopy could examine and certify the accuracy and integrity for the qualitative analysis of GC-MS. The results of this study provides an important guiding role for the development of wastewater treatment process.

[Sulfide removal from wastewater by nanoscale iron].

Influencing factors, adsorption isotherm, adsorption kinetics and preliminary discussion on the mechanism of sulfide adsorption by nanoscale iron prepared in laboratory were studied using manual simulation sulfide wastewater. Experimental results indicate that the removal efficiency of S2- increases with increasing iron dosage and decreases with increasing initial S2- concentration and pH values. The removal efficiency of S2- is 100% when initial concentration is less than 100 mg x L(-1) and are 87.34%, 65.80% and 44.61% at pH 2, 7 and 13. The temperature at 25 degrees C favors the maximum adsorption of S2- with 19.17 mg x g(-1) of equilibrium adsorption quantity and the adsorption capacity decreas at higher or lower temperature. The adsorption data fit well to the Langmuir equation and the Freundlich equation. The sulfide adsorption follows the pseudo second order equation with the maximum initial sorption rate(h) is 1.575 3 mg x (g x mg)(-1) at 25 degrees C and the adsorption rate constant increases with the increasing of temperature. The activation energy(Ea) is 8.22 kJ x mol(-1). The mechanism of sulfide removal is being sorbed onto the iron nanoparticles via formation of surface compleses, FeOSH and iron sulfides (FeS, FeS2, FeSn).

[Dechlorination mechanisms of chlorinated hydrocarbons by supported nanoscale Pd/Fe].

Some volatile chlorinated hydrocarbons such as VC, 1,1-DCE, TCE, PCE, gamma-HCH, were dechlorinated by synthesized supported nanoscale Pd/Fe. The dechlorination reactions of PCE, TCE, 1,1-DCE, VC, gamma-HCH follow the pseudo-frist order kinetics equations with the k(obs) of 2.79 h(-1), 2.35 h(-1), 1.12 h(-1), 2.14 h(-1) and 4.02 h(-1) respectively. Little or no medial products were detected and the main end products were C2H6 and C2H4 during the dechlorination of VC, 1,1-DCE, TCE, PCE. The total carbon ratio of C2H6 and C2H4 were 70% and 10% respectively during the dechlorination of TCE. The supported nanoscale Pd/Fe particles after exposed to air for 24 h were used for 8 cycle experiments and the results indicate that the particles have favorable stability. The reactivity has no obvious decrease after 200 hours' successive dechlorination experiments of gamma-HCH which indicates that the particles represent good durability. The reaction activation energy of all the chlorinated hydrocarbons are bigger than 29 kJ x mol(-1) which shows that the surface-chemical reaction rather than diffusion is the rate-limiting step in the metal-mediated dechlorination process. A consistence between the experimental data and simulated curves indicates that the muti-step reaction pathways proposed offer a better explanation of the reaction mechanisms than sequential hydrogenolysis reactions in the transformation of chlorinated hydrocarbons by supported nanoscale Pd/Fe.

Biodegradation of tetrachlorothylene using methanol as co-metabolic substrate.

OBJECTIVE: To investigate the biodegradation of tetrachloroethylene (PCE) using methanol as electron donor by acclimated anaerobic sludge. METHODS: HP-6890 gas chromatograph (GC), together with HP-7694 autosampler, was used to analyze the concentration of PCE and intermediates. RESULTS: PCE could be decholrinated reductively to DCE via TCE, and probably further to VC and ethylene. The degradation of PCE and TCE conformed to first-order reaction kinetics. The reaction rate constants were 0.8991 d(-1) and 0.068 d(-1), respectively, and the corresponding half-life were 0.77 d and 10.19 d, respectively. TCE production rate constant was 0.1333 d(-1), showing that PCE was degraded more rapidly than TCE. CONCLUSION: Methanol is an electron donor suitable for PCE degradation and the cometabolic electron donors are not limiting factors for PCE degradation.