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1.
J Integr Med ; 22(2): 163-179, 2024 Mar.
Article in English | MEDLINE | ID: mdl-38519277

ABSTRACT

BACKGROUND: Ginkgo biloba L. preparations (GBLPs) are a class of Chinese herbal medicine used in the adjuvant treatment of ischemic stroke (IS). Recently, several systematic reviews (SRs) and meta-analyses (MAs) of GBLPs for IS have been published. OBJECTIVE: This overview aims to assess the quality of related SRs and MAs. SEARCH STRATEGY: PubMed, Embase, Cochrane Library, Web of Science, Chinese Biological Medicine, China National Knowledge Infrastructure, Wanfang, and Chinese Science and Technology Journals databases were searched from their inception to December 31, 2022. INCLUSION CRITERIA: SRs and MAs of randomized controlled trials (RCTs) that explored the efficacy of GBLPs for patients with IS were included. DATA EXTRACTION AND ANALYSIS: Two independent reviewers extracted data and assessed the methodological quality, risk of bias (ROB), reporting quality, and credibility of evidence of the included SRs and MAs using A Measurement Tool to Assess Systematic Reviews 2 (AMSTAR 2), Risk of Bias in Systematic Reviews (ROBIS), the Preferred Reporting Items for Systematic Reviews and Meta-analyses (PRISMA), and the Grading of Recommendations Assessment, Development and Evaluation (GRADE), respectively. Additionally, descriptive analysis and data synthesis were conducted. RESULTS: Twenty-nine SRs/MAs involving 119 outcomes were included in this review. The overall methodological quality of all SRs/MAs was critically low based on AMSTAR 2, and 28 had a high ROB based on the ROBIS. According to the PRISMA statement, the reporting items of the included SRs/MAs are relatively complete. The results based on GRADE showed that of the 119 outcomes, 8 were rated as moderate quality, 24 as low quality, and 87 as very low quality. Based on the data synthesis, GBLPs used in conjunction with conventional treatment were superior to conventional treatment alone for decreasing neurological function scores. CONCLUSION: GBLPs can be considered a beneficial supplemental therapy for IS. However, because of the low quality of the existing evidence, high-quality RCTs and SRs/MAs are warranted to further evaluate the benefits of GBLPs for treating IS. Please cite this article as: Meng TT, You YP, Li M, Guo JB, Song XB, Ding JY, Xie XL, Li AQ, Li SJ, Yin XJ, Wang P, Wang Z, Wang BL, He QY. Chinese herbal medicine Ginkgo biloba L. preparations for ischemic stroke: An overview of systematic reviews and meta-analyses. J Integr Med. 2024;22(2): 163-179.


Subject(s)
Drugs, Chinese Herbal , Humans , Drugs, Chinese Herbal/therapeutic use , Ginkgo biloba , China
2.
Front Immunol ; 13: 1015142, 2022.
Article in English | MEDLINE | ID: mdl-36405700

ABSTRACT

Diabetic nephropathy (DN) is the most common chronic kidney disease. Accumulation of glucose and metabolites activates resident macrophages in kidneys. Resident macrophages play diverse roles on diabetic kidney injuries by releasing cytokines/chemokines, recruiting peripheral monocytes/macrophages, enhancing renal cell injuries (podocytes, mesangial cells, endothelial cells and tubular epithelial cells), and macrophage-myofibroblast transition. The differentiation and cross-talks of macrophages ultimately result renal inflammation and fibrosis in DN. Emerging evidence shows that targeting macrophages by suppressing macrophage activation/transition, and macrophages-cell interactions may be a promising approach to attenuate DN. In the review, we summarized the diverse roles of macrophages and the cross-talks to other cells in DN, and highlighted the therapeutic potentials by targeting macrophages.


Subject(s)
Diabetes Mellitus , Diabetic Nephropathies , Mice , Animals , Diabetic Nephropathies/metabolism , Endothelial Cells/metabolism , Mice, Inbred C57BL , Macrophages/metabolism , Kidney/metabolism , Diabetes Mellitus/metabolism
3.
Huan Jing Ke Xue ; 39(2): 811-818, 2018 Feb 08.
Article in Zh | MEDLINE | ID: mdl-29964845

ABSTRACT

Three autotrophic packed-bed reactors, each with a different sulfur/quartz sand ratio(R1, 2:1; R2, 1:1; R3, 1:2,)were used to remove high-concentration perchlorate from contaminated water. The perchlorate removal efficiency, kinetics, and biofilm of the reactors were studied using different perchlorate concentrations and hydraulic retention times (HRTs). The perchlorate removal efficiency decreased with higher perchlorate concentration and shorter HRT, and the removal efficiency of R1 was higher than of R2 and R3. The maximum removal loading of R1 was 2.18 kg·(m3·d)-1at an HRT of 3.2 h and perchlorate concentration of 300 mg·L-1. The half-order kinetics model fit the reactors' experimental data well; the reaction rate constants of R1, R2, and R3 were 8.036, 6.596, and 4.212 mg1/2·(L1/2·h)-1. The yield of SO42- was greater than the stoichiometric yield of sulfur autotrophic reduction owing to sulfur disproportionation. The disproportionation was inhibited with a higher perchlorate concentration or shorter HRT. Moreover, disproportionation of R3 was the weakest because the SO42- yield of R3 was lower than of R1 and R2. The pH and alkalinity of the effluent increased with lower perchlorate concentration and shorter HRT. The development of biofilm in R2 and R3 was better than in R1. The secretion of extracellular polymeric substances can promote the formation of biofilm.


Subject(s)
Bioreactors , Perchlorates/isolation & purification , Quartz , Sulfur , Biofilms , Kinetics
4.
J Pharm Sci ; 107(7): 1879-1885, 2018 07.
Article in English | MEDLINE | ID: mdl-29518401

ABSTRACT

The objective of this study was to investigate the effect of dispersion states of azone in gels on the transdermal permeation of levamisole hydrochloride (LH). LH hydroalcoholic gels containing azone of different dispersion states were prepared by varying the contents of azone and Tween 80, and the in vitro transdermal permeation of LH across excised rat skin was evaluated. Depending on the content of azone, mixed solvents, and solubilizer used, azone presented as dissolved molecules, solubilized in micelles, and fine or coarse emulsion droplets in gels. Dramatically increased transdermal permeation of LH within the azone contents between 0.25% and 0.75% indicated high transdermal enhancement efficiency of the molecular or micellar azone, and extra azone that existed as oil droplets did not fully exert transdermal penetration enhancement of LH. Although solubilizer (Tween 80) can greatly increase the solubility of azone, only small amount of Tween 80 (0.5%) in the gel significantly increased the steady-state flux of LH. Addition of extra amount of Tween 80 (>0.5%) reduced the amount of azone distributed in the skin, and thus decreased the transdermal drug permeation. The results partly elucidated the versatile effects of the dispersion states of azone on the transdermal permeation of hydrophilic drug from semisolid gels.


Subject(s)
Antinematodal Agents/pharmacokinetics , Antirheumatic Agents/pharmacokinetics , Azepines/chemistry , Hydrogels/chemistry , Levamisole/pharmacokinetics , Skin Absorption/drug effects , Administration, Cutaneous , Animals , Antinematodal Agents/administration & dosage , Antirheumatic Agents/administration & dosage , Azepines/pharmacology , Hydrogels/pharmacology , Levamisole/administration & dosage , Male , Micelles , Permeability/drug effects , Rats, Sprague-Dawley , Skin/drug effects , Skin/metabolism , Solubility
5.
Huan Jing Ke Xue ; 39(12): 5558-5564, 2018 Dec 08.
Article in Zh | MEDLINE | ID: mdl-30628400

ABSTRACT

The heterotrophic-autotrophic reactor including two chambers, that is, the lower part of the heterotrophic zone and the upper part of the autotrophic zone, was used to remove highly concentrated perchlorate (ClO4-) wastewater. The reduction characteristics of ClO4- and the effluent sulfur (SO42-) concentration were investigated using different influent ClO4- concentrations and C/Cl ratios. By adjusting the influent C/Cl ratio from 2 to 1, the reactor was started up successfully within 36 d. The microorganisms tolerated the high concentration of ClO4- (250-400 mg·L-1) and the ClO4- removal efficiency was higher than 95%. By adjusting the C/Cl ratio to 1.2, the ClO4- load in the autotrophic zone was reduced and the SO42- concentration in the effluent was controlled below 250 mg·L-1. The result show that tryptophan and tyrosine materials in soluble microbial products led to the TOC increase in the effluent of the autotrophic zone. The sludge yield was reduced because of heterotrophic and autotrophic processes. The alkalinity produced by the heterotrophic process was used as carbon source for the autotrophic process and to neutralize the acidity produced by the autotrophic process, representing the complementary function and avoiding the addition of alkalinity in the autotrophic process.


Subject(s)
Autotrophic Processes , Bioreactors , Heterotrophic Processes , Perchlorates/isolation & purification , Sulfur
6.
Huan Jing Ke Xue ; 38(1): 247-252, 2017 Jan 08.
Article in Zh | MEDLINE | ID: mdl-29965053

ABSTRACT

The effects of perchlorate concentration and hydraulic retention time (HRT) on perchlorate reduction characteristics were investigated in a sulfur-based perchlorate reduction reactor.The results showed that the perchlorate was completely removed at HRT of 12 h and the influent perchlorate concentration ranged from 50 mg·L-1 to 194 mg·L-1;The perchlorate removal efficiency was 74% at HRT of 4 h and the influent perchlorate concentration was 194 mg·L-1;The yield of sulfate was increased by increasing the influent perchlorate concentration and HRT;The influent pH and alkalinity was approximately 8.0 and 500 mg·L-1 CaCO3,and the effluent pH and alkalinity was approximately 6.7 and 100 mg·L-1 CaCO3,respectively;The oxidation reduction potential (ORP) ranged from -380 mV to -330 mV at the bottom of the reactor,however,ORP ranged from -300 mV to -250 mV at the top of the reactor;The molecular biological analysis showed that the microbial consortium structure was different along the flow path in the reactor,Sulfurovum which is known to oxidize sulfur was decreased from 57.78% to 32.19% and Hydrogenophilaceae which is known to oxidize hydrogen sulfide was increased from 4.35% to 22.24%.


Subject(s)
Bioreactors/microbiology , Perchlorates/metabolism , Sulfur/analysis , Hydrogen-Ion Concentration , Oxidation-Reduction , Sulfates/analysis
7.
Huan Jing Ke Xue ; 37(3): 988-93, 2016 Mar 15.
Article in Zh | MEDLINE | ID: mdl-27337891

ABSTRACT

The perchlorate reduction lag phase of the strain GWF (KM062029) was shortened by using non-dissolved quinone. nthraquinone, 1-chloroanthraquinone, 1,5-dichloroanthraquinone, 1,8-dichloroanthraquinone and 1,4,5,8-tetrachloranthtaquinone were the five non-dissolved quinones in this study. The results showed that the accelerating order was 1,5-dichloroanthraquinone > 1,4, 5,8-tetrachloroanthtaquinone > 1,8-dichloroanthraquinone > Anthraquinone > 1-chloroanthraquinone. The optimal concentration of 1,5- dichloroanthraquinone, temperature and pH for perchlorate reduction were 0.036 mmol · L⁻¹, 35 °C and 7.5, respectively. The concomitant anions (nitrate, phosphate, sulfate) were in favor of the perchlorate reduction by strain GWF. After four times of recycling experiments, the accelerating perchlorate reduction rate with the immobilized 1,5-dichloroanthraquinone maintained above 2 times.


Subject(s)
Perchlorates/chemistry , Quinones/chemistry , Nitrates/chemistry , Oxidation-Reduction , Phosphates/chemistry , Sulfates/chemistry
8.
J Environ Sci (China) ; 17(6): 984-8, 2005.
Article in English | MEDLINE | ID: mdl-16465892

ABSTRACT

Because the lack of detailed study of biological decolorization in high salt dye wastewater, it is still difficult to evaluate the biological treatment on high-salinity dye wastewater. The experiments were carried out to study the salt-tolerant bacteria, which is useful in the treatment of high-salinity colored wastewater. Simulated wastewater containing 5-150 g/L salt (NaCl) and 50-2000 mg/L Reactive Brilliant Red K-2BP was treated with three salt-tolerant mixed cultures (CAS, TAS, DSAS), which were under a gradually acclimated procedure. With the increase of concentrations of salt and dye, the decolorization became low. The abilities of decolorization of dyes wastewater by three mixed cultures (CAS, TAS, DSAS) were studied, CAS and DSAS mixed cultures showed more active for the treatment of high-salinity colored wastewater than TAS mixed cultures. The results suggested that there might be a simple process for the high salt wastewater treatment, which could be incorporated into conventional activated sludge plants.


Subject(s)
Azo Compounds/metabolism , Bacteria, Anaerobic/metabolism , Coloring Agents/metabolism , Waste Disposal, Fluid/methods , Water Purification/methods , Azo Compounds/chemistry , Biodegradation, Environmental , Coloring Agents/chemistry , Sodium Chloride/metabolism , Spectrophotometry, Ultraviolet
9.
Huan Jing Ke Xue ; 36(4): 1374-8, 2015 Apr.
Article in Zh | MEDLINE | ID: mdl-26164914

ABSTRACT

Anthraquinone sodium sulfonate (AQS) was immobilized on polyethylene terephthalate (PET) by chemical synthesis, forming quinone functional polymer biocarrier (PET-AQS), and its characteristics in biodenitrification catalysis were analyzed. Quinone group was demonstrated to be successfully immobilized on the surface of the polymer and the concentration of immobilized quinone was 0.140 6 mmol x g(-1) by Attenuated Total Reflectance Spectrometry (ATR-IR) and Energy Dispersive Spectrometry (EDS). The PET-AQS could accelerate biodenitrification. The relationship between the denitrification rate constant (K(x)) and the PET-AQS concentration (C(PET-AQS)) obeyed the pseudo-zero order kinetics. After ten rounds of recycling in the biodenitrification system with approximately 0.056 2 mmol quinone, the denitrification rate was kept at more than 1.2 times of the blank system. This indicated that PET-AQS exhibited a good operational stability and was beneficial to practical application.


Subject(s)
Anthraquinones/chemistry , Denitrification , Polyethylene Terephthalates/chemistry , Catalysis , Ions
10.
Huan Jing Ke Xue ; 35(5): 1843-9, 2014 May.
Article in Zh | MEDLINE | ID: mdl-25055676

ABSTRACT

Electrochemical oxidation degradation of azo dyes has become a widely used method in recent years. Iron phosphomolybdate (FePMo12) was synthesized with molybdophosphoric acid and ferric salt. Morphology and microstructure of catalyst were chararerized by IR spectrometry and X-ray diffraction. The heteropolyanion showed a Keggin structure. Electrochemical oxidation of acid red 3R was investigated in the presence of FePMo12 supported on modified 4A molecular sieve (4A) as packing materials in the reactor. The results showed that the optimal technological conditions for decolorization of acid red 3R simulated wastewater were as follows: active component load 3% , electrolytic voltage 22 V, initial pH 4, air-flow 0.08 m3 h- ', electrode span 3.0 cm. Under the opñrrizd conditions, the decolorization efficiency, COD and TOC removal efficiencies reached 75.3% , 65.4% and 46.0% after 90 min, respectively. With the addition of NaCI to the dyes solution during electrolysis, the decolorization efficiency increased, while the effect of Na2SO4 on the degradation was negative. The efficiency of degradation and mineralization of the acid red 3R were estimated based on the absorbance measurements by UV-vis. It shows that the conjugated structure of dye was destroyed primarily.


Subject(s)
Coloring Agents/chemistry , Waste Disposal, Fluid/methods , Wastewater/chemistry , Catalysis , Electrodes , Iron/chemistry , Molybdenum/chemistry , Oxidation-Reduction , Phosphoric Acids/chemistry , Rhodamines/chemistry , X-Ray Diffraction
11.
Huan Jing Ke Xue ; 35(5): 1838-42, 2014 May.
Article in Zh | MEDLINE | ID: mdl-25055675

ABSTRACT

The technology of non-water-soluble mediator anaerobic biological catalysis has attracted more and more attention in the field of environment technology. In this study, five kinds of quinonly compounds were grafted on the chloromethylation polystyrene macromolecular carrier by Friedel-Crafts reaction. Reaction factors of temperature and molar ratio for the 1,4-naphthoquinone grafting carrier were optimized, and the optimal temperature was 78 degreesC while the optimal molar ratio of 1, 4-naphthoquinone and chloromethylation polystyrene was 2: 1. Fourier infrared spectrum analysis confirmed that the quinone groups were successfully grafted on the macromolecular backbone chloromethylation polystyrene. Catalysis using the five kinds of quinonly materials as non-water-soluble redox mediators enhanced the biological denitrification rate and the decoloration of azo dyes, meanwhile these materials showed good reusability in the biodegradation of azo dye. This study developed a new method for the preparation of quinonly materials and revealed a new field in the technology of mediator catalysis.


Subject(s)
Azo Compounds/chemistry , Coloring Agents/chemistry , Polystyrenes/chemistry , Waste Disposal, Fluid/methods , Wastewater/chemistry , Biodegradation, Environmental , Catalysis , Naphthoquinones/chemistry , Oxidation-Reduction
12.
Huan Jing Ke Xue ; 34(3): 955-61, 2013 Mar.
Article in Zh | MEDLINE | ID: mdl-23745400

ABSTRACT

Supported phosphotungstic acid catalysts on gamma-Al2O3 (HPW/gamma-Al2O3) were prepared by solution impregnation and characterized by FTIR, XRD, TG-DTA and SEM. The heteropolyanion shows a Keggin structure. Electro-chemical oxidation of Acid Red 3R was investigated in the presence of HPW supported on gamma-Al2O3 as packing materials in the reactor. The results show that HPW/gamma-Al2O3 has a good catalytic activity for decolorization of Acid Red 3R. When HPW loading was 4.6%, pH value of Acid Red 3R was 3, the voltage was 25.0 V, air-flow was 0.04 m3 x h(-1), and electrode span was 3.0 cm, the decolorization efficiency of Acid Red 3R can reach 97.6%. The removal rate of color had still about 80% in this electro-chemical oxidation system, after HPW/gamma-Al2O3 was used for 10 times, but active component loss existed. The interim product was analyzed by means of Vis-UV absorption spectrum. It shows that the conjugated structure of dye is destroyed primarily.


Subject(s)
Aluminum Oxide/chemistry , Electrochemical Techniques/methods , Phosphotungstic Acid/chemistry , Rhodamines/isolation & purification , Waste Disposal, Fluid/methods , Catalysis , Electrochemical Techniques/instrumentation , Electrodes , Oxidation-Reduction , Rhodamines/chemistry , Wastewater/chemistry
13.
Huan Jing Ke Xue ; 34(9): 3520-5, 2013 Sep.
Article in Zh | MEDLINE | ID: mdl-24288999

ABSTRACT

This study optimized the nitrite degradation conditions and explored the characteristics of nitrite degradation with redox mediators and nitrite denitrifying bacteria. The results suggested that the optimal condition of nitrite denitrification was 35 degrees C, pH = 8.0, sodium succinate as the carbon source, the C/N rate of 4 and the initial nitrite concentration of 100 mg x L(-1); the optimal AQS concentration was 0. 16 mmol x L(-1); ORP values stabilized around -400 mV to -500 mV with AQS, which were lower than that of controls during the denitrification process; the pH changed with nitrite removal and stabilized at 9 to 10; through the analysis of denitrifying intermediate metabolites, the impact of AQS on nitrite denitrifying process presumably not only played a coenzyme CoQ role but also accelerated the cytochrome transfer electronic process. This study provides the optimal parameters for practical application of the nitrite biodegradation with redox mediator.


Subject(s)
Bacteria/metabolism , Denitrification , Nitrites/chemistry , Biodegradation, Environmental , Oxidation-Reduction
14.
Huan Jing Ke Xue ; 33(7): 2458-63, 2012 Jul.
Article in Zh | MEDLINE | ID: mdl-23002627

ABSTRACT

The quinone respiration process of Paracoccus versutus strain GW1 was characterized and the effects of the four redox mediators on the denitrification process were studied. The experiment results suggested that quinones were utilized by Paracoccus versutus strain GW1 as electron acceptors in the respiratory chain and reduced to hydroquinone. Batch experiments were carried out to investigate the biocatalyst effect of redox mediators as catalyst on the denitrification process at 35 degrees C. All four redox mediators tested were able to enhance the nitrate removal efficiency and the denitrification efficiency by 1.14-1.63 fold and 1.12-2.02 fold, respectively. The accelerating effect from high to low was AQDS > 1,5-AQDS > AQS > alpha-AQS. In the presence of redox mediators, the stabilized ORP values in the nitrate decomposition process were reduced by 33-75 mV. The pH variations in denitrification with redox mediators showed similar tendency to that of the conventional nitrate removal process. In the concentration range of 0-0.32 mmol x L(-1), AQDS had the best accelerating effect and a linear correlation was found for the denitrification rate K and the AQDS concentration cAQDS. This study indicated that the application of redox mediators significantly improved the denitrification process by enhancing the decomposition rate.


Subject(s)
Denitrification , Nitrates/isolation & purification , Paracoccus/metabolism , Water Pollutants, Chemical/isolation & purification , Benzoquinones/chemistry , Benzoquinones/metabolism , Biocatalysis , Biodegradation, Environmental , Nitrates/metabolism , Oxidation-Reduction , Paracoccus/classification , Water Pollutants, Chemical/metabolism
15.
Huan Jing Ke Xue ; 32(4): 1060-5, 2011 Apr.
Article in Zh | MEDLINE | ID: mdl-21717748

ABSTRACT

Four selected quinone redox mediators with similar structure were conducted to accelerate reactive brilliant red K-2BP decolorization, and the accelerating structure-activity of redox mediators on the decolorization was also studied. Batch experiments were carried out to determine the catalyst effect on the decolorization of reactive brilliant red K-2BP with temperature of 35 degrees C and under anaerobic conditions. The experiment results suggested that (1) four similar chemical structure redox mediators [1, 4, 5, 8-Tetrachloroanthraquinone (1,4,5,8-AQ), Anthraquinone (AQ), 1,8-Dichloroanthraquinone (1,8-AQ), 1,5-Dichloroanthraquinone (1,5-AQ)], all accelerated the decolorization rate of reactive brilliant red K-2BP and the reaction rate was enhanced 1.4-3 times; (2) the accelerating order was 1,8-AQ >1 ,5-AQ > AQ >1,4,5,8-AQ at the quinone mediator concentration of 4 mmol x L(-1) and reactive brilliant red K-2BP concentration of 300 mg x L(-1); (3) under the reactive brilliant red K-2BP concentration of 300 mg x L(-1), 1,8-AQ had best accelerating effect, and the relationship between decoloring rate constants and 1,8-AQ concentration; (4) and the mediator acclerating effects also related to substituent positioning effects and conjugated effects. The structure-activity mathematical model of redox mediators was put forward, which could improve water-insoluble redox mediators catalytic strengthening theory system.


Subject(s)
Azo Compounds/isolation & purification , Industrial Waste/analysis , Quinones/chemistry , Waste Disposal, Fluid/methods , Anaerobiosis , Anthraquinones/chemistry , Azo Compounds/metabolism , Catalysis , Color , Coloring Agents/chemistry , Coloring Agents/metabolism , Oxidation-Reduction , Structure-Activity Relationship , Water Purification/methods
16.
Huan Jing Ke Xue ; 31(3): 725-30, 2010 Mar.
Article in Zh | MEDLINE | ID: mdl-20358834

ABSTRACT

Methanogens is considered to be important functional microbial population in anaerobic granular sludge. Fluorescence in situ hybridization was used to analyze methanogens of anaerobic granular sludge in a full-scale UASB treating avermectin wastewater. The results indicated that the distribution forms of methanogens, Methanobacteriales and Methanosarcinales were identical on the surface and inner face of granular sludge samples in different formation stages (with different diameters) , although the relative abundances of these methanogens were different. The relative abundances of methanogens on the inner face were larger than these on the surface of granular sludge samples. The relative abundances of Methanobacteriales were larger than these of Methanosarcinales. The relative abundances of methanogens in all granular sludge samples ranged from (25.50 +/- 8.63)% to (48.67 +/- 8.87)%. The maximum relative abundances of methanogens were obtained in mature granular sludge with diameter of 1.0-2.0 mm, (47.08 +/- 8.26)% on the surface and (48.67 +/- 8.87)% on the inner face, respectively. The avermectin residue in wastewater showed possible inhibition effect on methanogens. The maximum specific methanogenic activities of granular sludge samples ranged from 1.311 to 1.562 g/(g x d), varying as same as COD removal ratios and relative abundances of methanogens, implying the strong correlation of methanogens with bioactivity of granular sludge.


Subject(s)
Bioreactors/microbiology , Ivermectin/analogs & derivatives , Methanobacteriales/classification , Sewage/microbiology , Waste Disposal, Fluid/methods , Anaerobiosis , Ivermectin/isolation & purification , Ivermectin/metabolism , Methanobacteriales/metabolism , Methanomicrobiaceae/metabolism , Methanosarcina/metabolism , Population Dynamics
17.
Huan Jing Ke Xue ; 27(10): 2067-70, 2006 Oct.
Article in Zh | MEDLINE | ID: mdl-17256611

ABSTRACT

Experiments were conducted to study some electrochemical factors affecting the bacterial reduction (cleavage) of four azo dyes. And a common mixed culture was used as test organism and the reduction of azo dyes Acid Yellow 4, 11, 17 and Acid Yellow Bis was studied. It was found that the azo dyes were reduced at different rates,which could be correlated with the reduction potential of the azo compounds in cyclic voltammetric experiments. Acid Yellow Bis (Er = -616.75 mV) was reduced at the highest rate of 0.01209 mol x (L x h)(-1), Acid Yellow 11 (Er = -593.25 mV) at 0.01040 mol x (L x h)(-1) and Acid Yellow 4 (Er = - 513 mV) at 0.007575 mol x (L x h)(-1). It is showed that the reduction potential is a preliminary tool to predict the decolorization capacity of oxidative and reductive biocatalysts.


Subject(s)
Azo Compounds/metabolism , Bacteria, Anaerobic/metabolism , Coloring Agents/metabolism , Waste Disposal, Fluid/methods , Biodegradation, Environmental , Electrochemistry , Oxidation-Reduction
18.
Huan Jing Ke Xue ; 27(10): 2071-5, 2006 Oct.
Article in Zh | MEDLINE | ID: mdl-17256612

ABSTRACT

The accelerating effect of anthanquinone as a redox mediator in the bio-decolorization was conducted. Decolorization of azo dyes was carried out experimentally using the salt-tolerant bacteria under immobilized anthanquinone and high salt conditions. Anthnaquinone used as a redox mediator was able to increase the decolorization rate of wastewater containing azo dyes, and was immobilized by entrapment in calcium alginate (CA), polyvinyl alcohol (PVA)-H3BO3, polyvinyl alcohol (PVA)-calcium alginate (CA) and agar, respectively. The effects of various operating conditions such as anthnaquinone bead number and dissolved oxygen on microbial decolorization were investigated experimentally. At the same time, immobilized anthanquinone was tested to assess the effects on the change of the oxidation-reduction potential (ORP) values during the decolorization processes. High decolorization rate was obtained in the presence of 200 anthnaquinone immobilization beads at 30 degrees C, which increased 1.5-2 fold, in comparison with the control of free-anthanquinone. The oxidation-reduction potential (ORP) values stabilized around -260 to approximately -265 mV after 6 hours anoxic conditions, which lowered ORP values around -10 to approximately -15 mV by anthanquinone. The reusability of the anthnaquinone immobilization beads was evaluated with repeated-bacth decolorization experiments. After four repeated experiments, the decolorization rate of calcium alginate (CA) immobilized anthnaquinone retained over 90% of their original activity.


Subject(s)
Anthraquinones/chemistry , Azo Compounds/metabolism , Bacteria, Anaerobic/metabolism , Coloring Agents/metabolism , Waste Disposal, Fluid/methods , Azo Compounds/chemistry , Biodegradation, Environmental , Bioreactors , Coloring Agents/chemistry , Oxidation-Reduction
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