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1.
International Eye Science ; (12): 1731-1735, 2022.
Article in Chinese | WPRIM | ID: wpr-942851

ABSTRACT

AIM:To observe the early variation trend of the vault after phakic posterior chamber implantable collamer lens/toric implantable collamer lens(ICL/TICL V4c)implantation and analyze the related influencing factors.METHODS:In this retrospective study, a total of 49 patients(98 eyes)who underwent ICL/TICL V4c implantation in the Lanzhou Huaxia Eye Hospital from October 2020 to March 2021 were enrolled. Preoperative ocular biometric parameters were collected, including spherical equivalent(SE), intraocular pressure, axial length, anterior chamber depth(ACD), lens thickness(LT), central corneal thickness, anterior chamber angle(ACA), anterior chamber volume(ACV), white to white corneal diameter(WTW), mean keratometry K1 and K2, and intraoperative implantation size of ICL. The vault was measured by anterior segment optical coherence tomography(AS-OCT)at 1, 3d, 1wk and 1mo after surgery. The patients were divided into insufficient vault group(<250μm, 12 eyes), normal vault group(250-750μm, 62 eyes)and excessive vault group(>750μm, 24 eyes)according to the vault at 1mo after surgery. The factors affecting the postoperative vault were analyzed.RESULTS:The mean vault values at 1 and 3d, 1wk and 1mo after surgery were 591.05±293.44, 599.62±309.78, 592.22±301.49 and 586.69±285.63μm, respectively. There were significant differences in WTW, ACA, ACV, ACD, ICL size and LT at 1mo after surgery(all P<0.05). The regression equation of vault at 1mo after surgery was as follows: vault(μm)=-3142.19+388.25×WTW+10.40×ACA-301.63×LT(R=0.674, R2=0.454, adjusted R2=0.436). WTW had the greatest influence on vault at 1mo after surgery(β=0.47, P<0.001), followed by LT(β=-0.34, P<0.001)and ACA(β=0.17, P=0.047).CONCLUSION:WTW, ACA and LT were the main factors that affected and predicted the vault at 1mo after ICL/TICL V4c implantation.

2.
China Journal of Chinese Materia Medica ; (24): 1596-1601, 2016.
Article in Chinese | WPRIM | ID: wpr-279201

ABSTRACT

The paper is aimed to study the distribution, population density, soil conditions and community characteristics of accompanying plants' in Enshi sub-regional different areas, with a typical habitats investigation method. The results showed that the wild Panax japonicus mainly distributed in moist places under the forests, by streams, or secondary forests of high grass, within east longitude 29°-30°, north latitude 108°-110°and about 1 000-15 00 meters above sea level. The soils were mainly tide soil and humus with yellow-brown soil, yellow soil and red soil, and the humus thickness was5-30 centimeter, pH 6.0-6.8, the moisture content of 16.8%-24.2%, soil bulk density of 1.39-2.12. Its geographical vegetation types were mainly evergreen coniferous forest, evergreen-deciduous mixture broad leaved forest and evergreen coniferous forest mixed deciduous broad-leaved forest, including three levels community structure of arbors, shrubs and herbaceous; Its accompanying plants reached 86 families, 118 genera, 134 species of seed plants, the arbors included 15 families, 21 genera, 26 species and the dominant species community mainly Pinaceae such as Pinus massoniana, P. tabuliformis, P. henryi and Taxodiaceae such as Cunninghamia lanceolata, Cryptomeria fortunei etc. The shrubs included 39 families, 54 genera, 62 species with the dominant species such as Camellia oleifera, Kalopanax septemlobus, Akebia trifoliata, Trachycarpusfortunei, Rhamnus globosa, Smilax corbularia and so on. The herbaceous included 32 families, 43 genera, 46 species, and Ferns such as the black-footed Dryopteris, Dryopteris crassirhizom, Coniogramme affinis, Polystichum tripteron, Adiantum pedatum, Lunathyrium acrostichoides, Woodsia ilvensis and Woodwardia japonica were dominant species. The cover layer covered a large number of lichens and mosses. The wild P. japonicus can be found among the P. massoniana, P. tabuliformis, P. henryi, lichens and mosses. These may indicate that the wild P. japonicusin Enshi requires higher demands on the ecological environment, its accompanying plants are mainly the tree layer-shrub layer-herb layer, and vertical structure is obvious. The study provides a basis for domestication and conservation of P. japonicus resources.

3.
Saudi Medical Journal. 2014; 35 (4): 329-335
in English | IMEMR | ID: emr-159348

ABSTRACT

Nasopharyngeal carcinoma [NPC] is a polygenic disease related to a variety of factors. With the development of the microRNAs [miRNAs] technique, researchers found a close link between miRNAs and NPC. Differentially expressed miRNAs exist in NPC and normal nasopharyngeal tissues; radiotherapy and chemotherapy also affect the expression of miRNAs in NPC tissues. Further studies showed that dysregulation and ectopic expression of miRNAs were involved in the occurrence and development of NPC by affecting the expression of oncogenes or tumor suppressor genes, or acting on relevant signal transduction pathways. It is of great significance to investigate the miRNAs related to the occurrence and development of NPC for the prevention and treatment of NPC

4.
Chinese Journal of Epidemiology ; (12): 1006-1009, 2013.
Article in Chinese | WPRIM | ID: wpr-320952

ABSTRACT

Objective The emerging reverse sequence on syphilis screening program generates special discordant results,characterized with the appearance of both positive treponemal test and negative nontreponemal test at the same time.The aim of this study was to analyze the characteristics of the discordant results among low syphilis prevalence population in China,to provide evidence for improving the process of reverse sequence syphilis screening program.Methods Laboratory data was retrospectively analyzed,under reverse sequence screening algorithm selecting ELISA as the initial screening test for syphilis.All the screening reactive samples were tested by TPPA for confirmation and by quantitative TRUST for the reactivity of syphilis.Results 666 out of a total of 21 049 serum samples were reactive under the screening program.Among the 666 reactive samples,169 were reactive to TRUST.One in the 169 samples was confirmed negative on TPPA,and the faulse positive rate on ELISA was 0.6% (1/169).In those 666 reactive samples,497 were nonreactive to TRUST.74 in the 497 samples were confirmed negative to TPPA,with faulse positive rate of ELISA as 14.9% (74/497).In the group of 591 TPPA confirmed positive samples,the TRUST negative rate was found 71.6% (423/591),significantly higher than the TRUST positive rate (chi-square test,x2=110.025,P=0.000).Conclusion Among the results fiom reverse sequence syphilis screening program,majority of the samples which showed positive treponemal antibody,would have negative nontreponemal antibody.We therefore recommended a more reasonable reverse sequence syphilis algorithm to be used.Faulse positivity could be eliminated if TPPA was performed on all screening reactive samples by ELISA a first and then followed by quantitative TRUST on samples that were TPPA confirmed as positive.

5.
Chinese Journal of Cardiology ; (12): 830-833, 2012.
Article in Chinese | WPRIM | ID: wpr-326410

ABSTRACT

<p><b>OBJECTIVE</b>To compare the efficacy between micro invasive occlusion procedure and extracorporeal circulation procedure for treating patients with simple ventricular septal defect.</p><p><b>METHODS</b>Two hundred and twenty patients with simple ventricular septal defect (except subarterial ventricular septal defect) were randomly divided into micro invasive group (n = 116) and traditional cardiopulmonary bypass surgery group (n = 104). Clinical data were collected and compared at baseline and at 3, 30 and 180 days after surgery.</p><p><b>RESULTS</b>Age, gender, body weight and ventricular septal defect type were similar between the two groups (all P > 0.05). Operation time and hospitalization duration were significantly shorter in the micro invasive group than the traditional cardiopulmonary bypass surgery group (all P < 0.05). The proportion of blood transfusion was less in micro invasive group than the traditional cardiopulmonary bypass surgery group [2.59% (3/116) vs. 72.12% (75/104), P < 0.01]. Three days after surgery, incidence of mild and above tricuspid insufficiency was less in micro invasive group than the traditional cardiopulmonary bypass surgery group [0.86% (1/116) vs. 2.88% (3/104), P < 0.05]. There was one patient developed mild pericardial effusion at 30 days post surgery in micro invasive group. There was no intracardiac infection in the two groups during follow-up. At 30 and 180 days post surgery, incidence of residual shunt was also less in micro invasive group than the traditional cardiopulmonary bypass surgery group [1.72% (2/116) vs. 7.69 (8/104) and 0(0/116) vs. 7.69(8/104), all P < 0.05]. After surgery for 3, 30 and 180 days, transthoracic echocardiography derived chamber size, left ventricular end-diastolic volume index and left ventricular ejection fraction were similar between the two groups (all P > 0.05).</p><p><b>CONCLUSIONS</b>The efficacy is similar for patients with simple ventricular septal defect (except subarterial ventricular septal defect) using micro invasive occlusion therapy or extracorporeal circulation surgery. Micro invasive occlusion procedure can shorten operation and hospitalization time, and reduce the need for blood transfusion and risk of developing procedural-related tricuspid insufficiency and post-procedural residual shunt.</p>


Subject(s)
Child , Child, Preschool , Female , Humans , Male , Cardiac Catheterization , Methods , Extracorporeal Circulation , Heart Septal Defects, Ventricular , General Surgery , Minimally Invasive Surgical Procedures , Treatment Outcome
6.
Chinese Journal of Cardiology ; (12): 984-988, 2011.
Article in Chinese | WPRIM | ID: wpr-268272

ABSTRACT

<p><b>OBJECTIVE</b>To evaluate the feasibility, safety and efficacy of transesophageal echocardiography (TEE) and transthoracic echocardiography (TTE) guided coated stent-graft implantation for patients with Stanford B aortic dissection.</p><p><b>METHODS</b>In 5 patients with CT confirmed Stanford B aortic dissection, TEE and TTE were used to determine the parameters for pre-surgery diagnosis and selection of suitable coated stent. During surgery, TEE and TTE provided real-time and dynamic monitoring and guiding for precise implantation of the coated stent to effectively seal the tear of the aortic dissection. After surgery, efficacy of implanted coated stent was evaluated by TTE.</p><p><b>RESULTS</b>In all 5 patients, the coated stents were successfully implanted in the true lumen, a small distal tear was not covered in 1 case. Displacement of stent-graft or new endoleak was not observed at follow-up examinations performed at 3 months post-surgery. There were no aortic perforation, renal failure, paraplegia or other complications. The medians of left ventricular ejection fraction (LVEF) in 2 days before surgery, 1 month post-surgery and 3 months post-surgery are 59.9%, 67.4% and 68.1% and the medians of fraction shortening (FS) are 31.4%, 33.7% and 39.1%. Compared with 2 days before surgery, significant increase of LVEF and FS was observed in 1 month post-surgery and 3 months post-surgery (all P < 0.05).</p><p><b>CONCLUSION</b>Our results showed that echocardiography guided coated stent-graft implantation for patients with Stanford B aortic dissection was safe and effective with lower risk of complications.</p>


Subject(s)
Aged , Female , Humans , Male , Middle Aged , Aortic Dissection , Diagnostic Imaging , General Surgery , Blood Vessel Prosthesis Implantation , Methods , Echocardiography , Echocardiography, Transesophageal , Feasibility Studies , Stents
7.
Journal of Central South University(Medical Sciences) ; (12): 328-332, 2007.
Article in Chinese | WPRIM | ID: wpr-813883

ABSTRACT

OBJECTIVE@#To analyze the multiple factors affecting the postoperative mechanical ventilation supporting time in infants less than 10 kg with simple congenital heart diseases and to seize time by the forelock of extube and improve the outcome of surgical treatment.@*METHODS@#Data of 231 infants less than 10 kg with atrial septal defect(ASD),ventricular septal defect, and combining patent ductus arteriosus were retrospectively analyzed. The multivaricate stepwise logistic regression statistics were done for the predisposing factors affecting the ventilative supporting time.@*RESULTS@#The ventilative supporting time was 3~375 (average 23.5 h) h. The multivaricate stepwise logistic regression analysis indicated that severe pulmonary hyperpressure, cross-cramp aortic time, cardiopulmonary bypass time, preoperational pulmonary infection, membrane oxygenator, modified ultrafiltration, weight, and postoperative complications were significantly correlated to the ventilative supporting time.@*CONCLUSION@#Severe pulmonary hyperpressure, preoperational pulmonary infection, long cross-cramp aortic time, long cardiopulmonary bypass time, postoperative complications all prolong the ventilation supporting time; the use of membrane oxygenator and modified ultrafiltration during the operation and big weight can diminish the pulmonary complications and shorten the ventilation supporting time.


Subject(s)
Child, Preschool , Female , Humans , Infant , Male , Cardiopulmonary Bypass , Ductus Arteriosus, Patent , General Surgery , Heart Defects, Congenital , General Surgery , Heart Septal Defects, Atrial , General Surgery , Heart Septal Defects, Ventricular , General Surgery , Logistic Models , Multivariate Analysis , Postoperative Period , Respiration, Artificial , Retrospective Studies , Time Factors
8.
Journal of Central South University(Medical Sciences) ; (12): 599-603, 2007.
Article in Chinese | WPRIM | ID: wpr-813833

ABSTRACT

OBJECTIVE@#To observe the structural and hemodynamic changes after the reconstruction of right ventricular outflow tract (RVOT) with valved bovine jugular vein conduit (BJVC) in the canine model by color Doppler echocardiography (UCG).@*METHODS@#BJVC was used in the reconstruction of RVOT of 32 canines. UCG was used to observe the structure of the right ventricle and RVOT. The structure and hemodynamics were observed, and the diameter, width, blood velocity and pressure gradient (PG) were measured between the right ventricle and the conduits.@*RESULTS@#In the first stage, UCG showed that PG between the right ventricle and BJVC was high in 5 canines, and a few anastomosis in BJVCs with main pulmonary artery was small. Blood velocity quickened and PG increased, and color Doppler showed that the bloodstream was very bright. In the second stage, 7 canines survived for 1 year after the implantation. One year after the operation, UCG showed that the valve closed well, no graft kinking or obvious regurgitation of the valve was observed. The PG of the valve was low. The BJVCs were unobstructed and there was no thrombus.All the valves of BJVC opened well except one. In the third stage, 20 canines survived for 1 year after the implantation. UCG showed that the valve motion was good, no graft kinking or obvious regurgitation of the valve was observed. No neoplasm was observed.@*CONCLUSION@#UCG is one of the most useful measurements in the structural and hemodynamic study of RVOT reconstruction by BJVC in the canine model. The good evaluation of UCG implies that it is important for the study and clinical practice.


Subject(s)
Animals , Cattle , Dogs , Female , Male , Blood Vessel Prosthesis , Echocardiography, Doppler, Color , Heart Ventricles , Diagnostic Imaging , General Surgery , Hemodynamics , Jugular Veins , Diagnostic Imaging , Transplantation , Pulmonary Artery , Diagnostic Imaging , General Surgery
9.
Journal of Zhejiang University. Science. B ; (12): 404-410, 2006.
Article in English | WPRIM | ID: wpr-251907

ABSTRACT

The aqueous phase oxidation of gaseous elemental mercury (Hg(0)) by potassium persulfate (KPS) catalyzed by Ag(+) was investigated using a glass bubble column reactor. Concentration of gaseous mercury and potassium persulfate were measured by cold vapor atom absorption (CVAA) and ion chromatograph (IC), respectively. The effects of pH value, concentration of potassium persulfate and silver nitrate (SN), temperature, Hg(0) concentration in the reactor inlet and tertiary butanol (TBA), free radical scavenger, on the removal efficiency of Hg(0) were studied. The results showed that the removal efficiency of Hg(0) increased with increasing concentration of potassium persulfate and silver nitrate, while temperature and TBA were negatively effective. Furthermore, the removal efficiency of Hg(0) was much better in neutral solution than in both acidic and alkaline solution. But the influence of pH was almost eliminated by adding AgNO(3). High Hg(0) concentration has positive effect. The possible reaction mechanism of gaseous mercury was also discussed.

10.
Journal of Zhejiang University. Science. B ; (12): 548-552, 2006.
Article in English | WPRIM | ID: wpr-251890

ABSTRACT

Two isomers of nitrochlorobenzene (o-, and p-NCB) were treated by a Pd/Fe catalyst in aqueous solutions through catalytic amination and dechlorination. Nitrochlorobenzenes are rapidly converted to form chloroanilines (CAN) first through an amination process, and then rapidly dechlorinated to become aniline (AN) and Cl(-), without the involvement of any other intermediate reaction products. The amination and dechlorination reaction are believed to take place predominantly on the surface site of the Pd/Fe catalysts. The dechlorination rate of the reductive degradation of the two isomers of nitrochlorobenzene (o-, and p-NCB) in the presence of Pd/Fe as a catalyst was measured experimentally. In all cases, the reaction rate constants were found to increase with the decrease in the Gibbs free energy (correlation with the activation energy) of NCBs formation; the activation energy of each dechlorination reaction was measured to be 95.83 and 77.05 kJ/mol, respectively for o- and p-NCB. The results demonstrated that p-NCBs were reduced more easily than o-NCBs.


Subject(s)
Catalysis , Industrial Waste , Iron , Chemistry , Isomerism , Kinetics , Metals , Chemistry , Nitrobenzenes , Chemistry , Palladium , Chemistry , Structure-Activity Relationship , Waste Disposal, Fluid , Methods , Water , Chemistry , Water Purification , Methods
11.
Acta Pharmaceutica Sinica ; (12): 1184-1187, 2006.
Article in Chinese | WPRIM | ID: wpr-281963

ABSTRACT

<p><b>AIM</b>To synthesize the selenophosphocholine analogues containing tegafur and test their antitumor activities.</p><p><b>METHODS</b>The cyclic glyceroselenophospholopid conjugate of tegafur was synthesized by the reaction of hexaethylphosphorous triamide with N1-(2-furanidyl)-N3-(hydroxyalkyl)-5-fluyorouracil and 1-O-hexadecyl glycerol as well as selenium in one-pot. Cyclic glyceroselenophospholopid conjugate of tegafur reacted with triethylamine to give title compounds.</p><p><b>RESULTS</b>Six new compounds have been synthesized. Their structures were confirmed by 1H NMR, 13P NMR and elemental analysis. Antitumor activity of the title compounds against PGA1 was tested.</p><p><b>CONCLUSION</b>The reaction of triethylamine with cyclic glyceroselenophospholopid conjugate of tegafur very readily occurred, which was finished within 2 h at room temperature. The opening-ring products of trans isomers showed antimutor activity against human uriaryl bladder cancer cell more effective than that of the tegafur.</p>


Subject(s)
Humans , Antineoplastic Agents , Pharmacology , Cell Line, Tumor , Magnetic Resonance Spectroscopy , Organoselenium Compounds , Pharmacology , Phosphorylcholine , Tegafur , Pharmacology , Urinary Bladder Neoplasms , Drug Therapy , Pathology
12.
Journal of Zhejiang University. Science. B ; (12): 307-310, 2005.
Article in English | WPRIM | ID: wpr-249215

ABSTRACT

Great attention should be paid now to simultaneously removing common pollutants, especially inorganic pollutants such as nitrate and heavy metals, as individual removal has been investigated extensively. Removing common pollutants simultaneously by iron metal is a very effective alternative method. Near neutral pH, heavy metals, such as copper and nickel, can be removed rapidly by iron metal, while nitrate removal very much slower than that of copper and nickel, and copper can accelerate nitrate removal when both are removed simultaneously. Even a little amount of copper can enhance nitrate removal efficiently. Different mechanisms of these contaminants removal by iron metal were also discussed.


Subject(s)
Copper , Chemistry , Environmental Pollution , Iron , Chemistry , Metals, Heavy , Chemistry , Nitrates , Chemistry , X-Ray Diffraction
13.
Journal of Zhejiang University. Science. B ; (12): 540-542, 2005.
Article in English | WPRIM | ID: wpr-249176

ABSTRACT

The effectiveness of vitamin C in treating Cr(VI)-contaminated water is being evaluated. Cr(VI) is an identified pollutant of some soils and groundwater. Vitamin C, an important biological reductant in humans and animals, can be used to transform Cr(VI) to essentially nontoxic Cr(III). The removal efficiency was 89% when the mass concentration of vitamin C was 80 mg/L in 60 min, and nearly 100% Cr(VI) was removed when the mass concentration was 100 mg/L. Our data demonstrated that the removal efficiency was affected by vitamin C concentration, the reaction temperature and the dissolved oxygen concentration. The reaction mechanism of Cr(VI) by vitamin C was presented. Our study opens the way to use vitamin C to remediate Cr(VI)-contaminated soils and groundwater.


Subject(s)
Ascorbic Acid , Chemistry , Biodegradation, Environmental , Chromium , Chemistry , Computer Simulation , Industrial Waste , Models, Chemical , Oxidation-Reduction , Oxygen , Chemistry , Solutions , Temperature , Water Purification , Methods
14.
Journal of Zhejiang University. Science. B ; (12): 553-558, 2005.
Article in English | WPRIM | ID: wpr-249173

ABSTRACT

Study on the effects of sonolysis, ozonolysis and US/O3 system on the decomposition of p-chlorophenol in aqueous solutions indicated that in the cases of US/O3 system, individual ozonolysis and sonolysis, the decomposition rate of p-chlorophenol reached 78.78%, 56.20%, 2.79% after a 16-min reaction while its CODcr (chemical oxygen demand) removal rate was 97.02%, 62.17%, 3.67% after a 120-min reaction. The decomposition reaction of p-chlorophenol follows pseudo-first-order kinetics. The enhancement factors of p-chlorophenol and its COD(cr) under US/O3 system reached 63% and 237% respectively. The main intermediates during the decomposition include catechol, hydroquinone, p-benzoquinone, phenol, fumaric acid, maleic acid, oxalic acid and formic acid. The decomposition mechanism of p-chlorophenol was also discussed.


Subject(s)
Chlorophenols , Chemistry , Radiation Effects , Computer Simulation , Industrial Waste , Kinetics , Models, Chemical , Ozone , Chemistry , Solutions , Sonication , Water , Chemistry , Water Purification , Methods
15.
Journal of Zhejiang University. Science. B ; (12): 569-573, 2005.
Article in English | WPRIM | ID: wpr-249170

ABSTRACT

Catalytic wet air oxidation (CWAO) of o-chlorophenol in wastewater was studied in a stainless steel autoclave using four different Fe catalysts in the temperature range of 100-200 degrees C. Experimental results showed that high rate of o-chlorophenol and COD(Cr) (Chemical Oxygen Demand, mg/L) removal by CWAO was obtained at relatively low temperature and pressure. The catalysts Fe2(SO4)3, FeSO4, Fe2O3 and FeCl3 all exhibited high catalytic activity. More than 93.7% of the initial COD(Cr) and nearly 100% of o-chlorophenol were removed at 150 degrees C after 150 min with FeSO4 as catalyst. The CWAO of o-chlorophenol was found to be pseudo-first order reaction with respect to o-chlorophenol, with activation energy of 75.56 kJ/mol in the temperature range of 100-175 degrees C.


Subject(s)
Catalysis , Chlorophenols , Chemistry , Industrial Waste , Iron , Chemistry , Kinetics , Models, Chemical , Oxidation-Reduction , Salts , Chemistry , Solutions , Temperature , Water Purification , Methods
16.
Journal of Zhejiang University. Science. B ; (12): 182-186, 2005.
Article in English | WPRIM | ID: wpr-316355

ABSTRACT

Reduction of nitrate by zero-valent iron is a highly exergonic reaction that has long been known to occur. Use of scrap iron filings (SIF) as the PRB (Permeable Reactive Barrier) material can be used to recycle certain by-products, and identify cheaper replacements for expensive conventional PRB materials, especially pure metallic iron. The feasibility of reductive denitrification of nitrate by SIF was studied by batch experiments. Operational parameters such as pH value, SIF dosage and initial concentration of nitrate were investigated. The removal efficiency of nitrate reached 80% under the conditions of pH of 2.5, nitrate initial concentration of 45 mg/L and SIF dosage of 100 g/L within 4 h. Results indicated that nitrate removal is inversely related to pH. Low pH value condition favors for the nitrate transformation. Different from the results of others who studied nitrate reduction using iron powder, we found that there was a lag time before nitrate reduction occurs, even at low pH. Finally, the possible mechanism of nitrate reduction by Fe0 is discussed.


Subject(s)
Computer Simulation , Feasibility Studies , Hydrogen-Ion Concentration , Iron , Chemistry , Models, Chemical , Nitrates , Chemistry , Nitrogen , Chemistry , Oxidation-Reduction , Water Pollutants, Chemical , Water Purification , Methods
17.
Journal of Zhejiang University. Science. B ; (12): 1022-1027, 2005.
Article in English | WPRIM | ID: wpr-263264

ABSTRACT

Groundwater remediation by nanoparticles has received increasing interest in recent years. This report presents a thorough evaluation of hexavalent chromium removal in aqueous solutions using iron (Fe(0)) nanoparticles. Cr(VI) is a major pollutant of groundwater. Zero-valent iron, an important natural reductant of Cr(VI), is an option in the remediation of contaminated sites, transforming Cr(VI) to essentially nontoxic Cr(III). At a dose of 0.4 g/L, 100% of Cr(VI) (20 mg/L) was degraded. The Cr(VI) removal efficiency decreased significantly with increasing initial pH. Different Fe(0) type was compared in the same conditions. The reactivity was in the order starch-stabilized Fe(0) nanoparticles>Fe(0) nanoparticles>Fe(0) powder>Fe(0) filings. Electrochemical analysis of the reaction process led to the conclusion that Cr(OH)(3) should be the final product of Cr(VI). Iron nanoparticles are good choice for the remediation of heavy metals in groundwater.


Subject(s)
Chromium , Chemistry , Electrochemistry , Fresh Water , Chemistry , Iron , Chemistry , Microscopy, Electron, Scanning , Nanostructures , Chemistry , Oxidation-Reduction , Spectrophotometry, Ultraviolet , Starch , Chemistry , Water Pollutants, Chemical
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