Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 19 de 19
Filtrar
Mais filtros










Base de dados
Intervalo de ano de publicação
1.
Huan Jing Ke Xue ; 38(5): 1852-1862, 2017 May 08.
Artigo em Chinês | MEDLINE | ID: mdl-29965089

RESUMO

Thirty-four water samples and twenty-three sediment samples from the urban rivers, ten water samples and five sediment samples from urban lakes were collected in Beijing. Ten PPCPs (acetaminophen, lincomycin, caffeine, trimethoprim, azithromycin, sulfamethoxazole, diltiazem, tylosin, carbamazepine, fluoxetine) were extracted from water samples by solid-phase extraction (SPE) and from sediment samples by ultrasonic extraction, and then analyzed by high-performance liquid chromatography coupled with tandem mass spectrometry (HPLC-MS/MS). The ranges of geometric mean values were 0-655 ng·L-1 and 0-252 ng·L-1 in water samples from urban rivers and lakes,respectively. The range of detection ratio was 0-100% for 10 PPCPs in river water samples, caffeine was the dominant pollutant in water samples and the detection ratio was 100%, whereas sulfamethoxazole, diltiazem and tylosin were not detected in river samples. The range of detection ratio was 0-100% for 10 PPCPs in lake water samples. The detection ratios of acetaminophen, lincomycin, caffeine and azithromycin were 100%, whereas sulfamethoxazole, diltiazem, tylosin, carbamazepine were not detected in lake water samples. The ranges of geometric mean values were N.D.-1709 ng·g-1and N.D.-35.9 ng·g-1in sediment samples from urban rivers and lakes, respectively. The ranges of detection ratio were 4%-96% and 0-100% for 10 PPCPs in river and lake sediment samples, respectively. The detection ratio of trimethoprim was 96% and that of tylosin was 4% in river sediment, the detection ratio of diltiazem was 100% and caffeine, tylosin,carbamazepine were not detected. The concentrations of PPCPs in water and sediment samples from Yongyin River, Liangshui River, Tonghui River, Bahe River were higher than those in other rivers. The concentrations of PPCPs in water and sediment samples from Yongding River,Kunyu River were lower than those in other rivers. Further risk assessment results showed that the overall risk was not high in water of rivers and lakes and the RQ values were below 0.1, which showed low risk to microorganisms. But the condition was not the same in sediment from rivers and lakes. The RQ values of acetaminophen were between 0.1 and 1 in sediments from Yongyin River, Tonghui River, Bahe River. The RQ values of lincomycin were between 0.1 and 1 in sediments from Yongyin River, Wenyu River,Tonghui River, Hucheng River, Bahe River, Liangshui River, Houhai Lake. The RQ values of trimethoprim were between 0.1 and 1 in sediments from Yongyin River, Qinghe River, Wenyu River, Tonghui River Hucheng River, Bahe River, Liangma River, Liangshui River and Houhai Lake. The RQ values of azithromycin were between 0.1 and 1 in sediments from Liangma River, Liangshui River, which all showed medium risk to microorganisms in sediments. The RQ values of azithromycin exceeded 1 from Yongyin River, Qinghe River, Wenyu River, Tonghui River, Bahe River and Houhai Lake, which showed high risk to microorganisms in sediments.


Assuntos
Monitoramento Ambiental , Sedimentos Geológicos/química , Lagos/química , Preparações Farmacêuticas/análise , Rios/química , Poluentes Químicos da Água/análise , Pequim , China , Espectrometria de Massas em Tandem , Microbiologia da Água
2.
Huan Jing Ke Xue ; 38(3): 1182-1188, 2017 Mar 08.
Artigo em Chinês | MEDLINE | ID: mdl-29965593

RESUMO

Sixty-eight fish samples were collected from typical epidemic areas of schistosomiasis prevalence. The contents of 12 CB congeners in fish samples were measured using GC/MS technique. The results indicated that 1,3-DIC, 1,4-DIC, 1,2-DIC and HCB were the most predominant CB congeners in the samples from the studying area. The source of HCB was PCP (pentachlorophenol), which was used to control the schistosomiasis prevalence, used in study area. And DIC came from the degradation of HCB and the articles of daily use. The geometric average of CBs in muscle ranged from 2731.50 to 7811.23 ng·g-1 lipid weight, while the summarized concentration of CBs in fish gonads, brains, kidneys, livers ranged from 2557.89 to 4640.05 ng·g-1 lipid weight, 2423.18 to 3329.61 ng·g-1 lipid weight, 1628.05 to 4667.76 ng·g-1 lipid weight and 704.92 to 1086.96 ng·g-1 lipid weight, respectively. When compared to other studies in China and other countries, the concentrations of CBs in these fish samples were at a relatively high level.


Assuntos
Clorobenzenos/análise , Monitoramento Ambiental , Peixes , Poluentes Químicos da Água/análise , Animais , China , Prevalência , Esquistossomose
3.
Huan Jing Ke Xue ; 37(9): 3348-3355, 2016 Sep 08.
Artigo em Chinês | MEDLINE | ID: mdl-29964768

RESUMO

Fourteen sediment samples from 15 river estuaries and six sediments from 6 drinking water resource were collected from Taihu Lake. Nine pharmaceutical and personal care products(PPCPs) in the sediments samples were measured by using the HPLC-MS/MS technique. The ranges of geometric mean values were 1.60-129 ng·g-1 and 1.36-22.0 ng·g-1, respectively. Caffeine was the dominant pollutant in fourteen sediments near the river estuary, the content of which covered 52% of amounts of 9 PPCPs. Lincomycin, trimethoprime, azithromycin, sulfamethoxazole and tylosin were the dominant pollutants in six sediments near the drinking water resource, the contents of which covered 79% of amounts 9 PPCPs. From the point of spatial distribution, the results of PPCPs in Zhushan bay and East of Yixing in the northwest and west of Taihu Lake showed higher concentration than those in other sample sites. From the composition, the origin of PPCPs was different. Municipal sewage, stock farming and aquaculture were the main sources of PPCPs in Taihu Lake. Pharmaceuticals of human use showed the dominant pollution in fourteen sediments near the river estuary and drugs of veterinary use showed the dominant pollution in six sediments near the water resource. The concentrations of PPCPs in fourteen sediments of river mouth showed high level. It suggested that PPCPs pollutants were discharged to Taihu Lake continuously. Further risk assessment results showed that the overall risk was not high except for some PPCPs compounds. The RQ exceeded 1 for acetaminophen, azithromycin and sulfamethoxazole in the surface sediments of 15 river estuaries and 6 water resources, which showed high risk. The RQ was between 0.01 to 0.1 for carbazepine in the surface sediments of 15 river estuaries and 6 water resources, which showed medium risk. The RQ was below 0.01 for caffeine, lincomycin, trimethoprim, diltiazem and tylosin in the sediments of 15 river estuaries and 6 water resources, which showed low risk.


Assuntos
Cosméticos/análise , Monitoramento Ambiental , Sedimentos Geológicos/química , Lagos/química , Preparações Farmacêuticas/análise , Poluentes Químicos da Água/análise , China , Água Potável/química , Estuários , Análise Espaço-Temporal , Espectrometria de Massas em Tandem
4.
Guang Pu Xue Yu Guang Pu Fen Xi ; 36(4): 1202-4, 2016 Apr.
Artigo em Chinês | MEDLINE | ID: mdl-30052347

RESUMO

Platinum group elements (PGEs) can be naturally found only at very low concentration in the earth crust. However, the increasing usage of PGEs in vehicle exhaust catalysts, and some other applications cause their anthropogenic emission and spread in the environment. Currently,the accumulation of PGEs in the environment has increased over the time. Catalytic converters of modern vehicles are considered to be the main sources of PGE pollution. In order to survey PGEs contamination at residential districts in the urban areas of Beijing City, roadside dust samples were collected. The roadside dust samples were digested with aqua regia and separated and purified with cation exchange resin (Dowex AG50W-X8), and then the resulting solutions were analyzed with inductively coupled plasma mass spectrometry (ICP-MS). PGEs pollution degree in dusts was analyzed using Geoaccumulation Index. The results showed that the concentrations of Pd, Pt and Rh in roadside dusts ranged from 14.20~161.80 ng·g-1 (50.76 ng·g-1), 9.39~70.80 ng·g-1(23.82 ng·g-1), 3.18~17.05 ng·g-1(7.54 ng·g-1), respectively. It indicated that concentrations of PGEs in dusts of residential areas were obviously higher than those values in Beijing soil background. The results of Geoaccumulation Index assessment indicated that the roadside dusts in residential areas were obviously polluted by the PGEs in Beijing city. The order of average pollution level of the PGEs is: Pd>Pt>Rh.

5.
Huan Jing Ke Xue ; 36(10): 3866-71, 2015 Oct.
Artigo em Chinês | MEDLINE | ID: mdl-26841624

RESUMO

Eleven mollusca samples and 32 fish samples were collected from typical epidemic areas of schistosomiasis prevalence. The contents of 12 CB congeners in aquatic organism samples were measured using the GC/MS technique. The results indicated that 1,3-DIC, 1,4-DIC, 1,2-DIC and HCB were the most predominant CB congeners in the samples from the studying area. The geometric average of CBs in muscle of mollusca was 11 947 ng x g(-1) lipid weight. The summarized concentration of CBs in fish muscle ranged from 1 851 to 8 159 ng x g(-1) lipid weight. The highest concentration of CBs sum was detected in the catfish, while the lowest one was found in the crucian carp. The concentrations of CBs in fish samples were much higher than those reported in other countries, while in mollusca samples were at the same level. The estimated cumulative cancerigenic risks for the local residents consumed the aquatic organisms from the studying area were 1.49 x 10(-7) and 3.73-21.1 x 10(-7), respectively for mollusca and fish, both of which were acceptable.


Assuntos
Monitoramento Ambiental , Bifenilos Policlorados/análise , Poluentes Químicos da Água/análise , Animais , Peixes , Cromatografia Gasosa-Espectrometria de Massas , Moluscos/química , Músculos/química , Medição de Risco , Esquistossomose
6.
Guang Pu Xue Yu Guang Pu Fen Xi ; 34(5): 1398-402, 2014 May.
Artigo em Chinês | MEDLINE | ID: mdl-25095446

RESUMO

The six heavy metal concentrations (Cr, Cr, As, Cd, Cu, Zn and Pb) in water samples collected from five reservoirs of Liao River Basin were studied. The health risk assessment for heavy metals pollution in reservoirs was conducted based on the environmental health risk assessment model recommended by U. S. Environmental Protection Agency. The results showed that the average concentrations of Cr, Cu, Zn, As, Cd and Pb in five reservoirs of Liao River Basin were 3.36, 1.03, 2. 70, 1.23, 0. 02 and 0. 03 microg L-1, respectively. In fact, these heavy metals concentrations were obviously lower than the Standard of National Drinking Water in China (GB 5749-2006). The results also showed that the metal carcinogenic risk was relatively high in this region. The order of the risk level of carcinogenic metals was Cr>As>Cd. The highest carcinogenic risk was from Cr, with the risk for adults ranging from 4. 50 X 10(-5) approximately 7. 53 X 10(-5) a-1' and the risk for children ranging from 6. 29 X 10(-5) to 1. 05 X 10(-4) a-1. The health risk levels caused by non-carcinogenic metals ranging from 10-13 to 10(-10) a-1 were lower than the acceptable range suggested by International Commission on Radiological Protection (ICRP) and the order of the risk level of non-carcinogenic metals was Cu>Zn>Pb. The total health risk of heavy metals for adults ranging from 1. 07X 10(-4) to 1. 72X 10(-4) a-1 and for children ranging from 1. 49 X 10(-4) to 2. 40 X 10(-4) a-1 exceeded the accepted level of 5 X 10(-5) a-1 as suggested by ICRP. The health risk levels of carcinogenic metals were significantly higher than those of non-carcinogenic metals in the reservoirs for Liao River Basin.


Assuntos
Água Potável/normas , Metais Pesados/análise , Medição de Risco , Poluentes Químicos da Água/análise , China , Água Potável/análise , Monitoramento Ambiental , Poluição Ambiental , Rios
7.
Environ Toxicol Chem ; 33(1): 170-6, 2014 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-24123209

RESUMO

Pentachlorophenol (PCP) is frequently detected in the aquatic environment and has been implicated as an endocrine disruptor in fish. In the present study, 4-month-old zebrafish (Danio rerio) were exposed to 1 of 4 concentrations of PCP (0.1, 1, 9, and 27 µg/L) for 70 d. The effects of PCP exposure on plasma thyroid hormone levels, and the expression levels of selected genes, were measured in the brain and liver. The PCP exposure at 27 µg/L resulted in elevated plasma thyroxine concentrations in male and female zebrafish and depressed 3, 5, 3'-triiodothyronine concentrations in males only. In both sexes, PCP exposure resulted in decreased messenger RNA (mRNA) expression levels of thyroid-stimulating hormone ß-subunit (tshß) and thyroid hormone receptor ß (trß) in the brain, as well as increased liver levels of uridine diphosphoglucuronosyl transferase (ugt1ab) and decreased deiodinase 1 (dio1). The authors also identified several sex-specific effects of PCP exposure, including changes in mRNA levels for deiodinase 2 (dio2), cytosolic sulfotransferase (sult1 st5), and transthyretin (ttr) genes in the liver. Environmental PCP exposure also caused an increased malformation rate in offspring that received maternal exposure to PCP. The present study demonstrates that chronic exposure to environmental levels of PCP alters plasma thyroid hormone levels, as well as the expression of genes associated with thyroid hormone signaling and metabolism in the hypothalamic-pituitary-thyroid (HPT) axis and liver, resulting in abnormal zebrafish development.


Assuntos
Pentaclorofenol/toxicidade , Hormônios Tireóideos/sangue , Poluentes Químicos da Água/toxicidade , Peixe-Zebra/metabolismo , Animais , Arilsulfotransferase/genética , Encéfalo/efeitos dos fármacos , Encéfalo/metabolismo , Feminino , Glucuronosiltransferase/genética , Iodeto Peroxidase/genética , Fígado/efeitos dos fármacos , Fígado/metabolismo , Masculino , Pré-Albumina/genética , RNA Mensageiro/metabolismo , Receptores beta dos Hormônios Tireóideos/genética , Tireotropina Subunidade beta/genética , Peixe-Zebra/genética , Proteínas de Peixe-Zebra/genética
8.
Huan Jing Ke Xue ; 34(10): 3847-53, 2013 Oct.
Artigo em Chinês | MEDLINE | ID: mdl-24364302

RESUMO

Heavy metals have been accumulated in sediment after impoundment in the Three Gorges Reservoir (TGR). In order to evaluate the risk of biomagnification of heavy metals, we investigated the trophic relationships and heavy metal concentrations in fish from a tributary within TGR. Sixteen fish species were collected from Daning River, and concentrations of eight heavy metal elements (Cr, Ni, Cu, Zn, Pb, Cd, As, and Hg) were determined, as well as the ratios of stable carbon and nitrogen isotopes. Results showed that most heavy metal concentrations were low in TGR, but changed significantly among different species. The delta13C values varied significantly among different groups (-22. 80 per thusand - 28. 97 per thusand) ; while the delta15N values (6. 41 per thusand - 13. 88 per thusand) varied based on their feeding types. A significantly trophic level-dependent increase was found in concentrations of Hg, indicating an overall biomagnification of Hg; but the increase of Hg concentration per trophic level was lower than that in previous studies. No tendency towards trophic-level enrichment was observed for other elements studied. However, a much higher heavy metal concentration was observed in small-sized fish samples, indicating a potential risk in environment.


Assuntos
Monitoramento Ambiental , Peixes , Cadeia Alimentar , Metais Pesados/análise , Poluentes Químicos da Água/análise , Animais , Isótopos de Carbono/análise , China , Mercúrio/análise , Isótopos de Nitrogênio/análise , Rios
9.
Huan Jing Ke Xue ; 34(6): 2198-204, 2013 Jun.
Artigo em Chinês | MEDLINE | ID: mdl-23947033

RESUMO

A total of 28 surface sediment samples (at the top 0-5 cm layer) were collected from the Three Gorges Reservoir of Yangtze River. The content of polybrominated diphenyl ethers (PBDEs) in sediments was measured with Varian GC-MS (NCI). The results showed that sigma26 PBDEs and BDE209 both had a low concentration in sediments, with a mass concentration of 35.24 pg x g(-1) and 11.92 pg x g(-1), respectively. Among the 26 PBDEs, BDE28, 47, 77 and 99 were the most predominant sigma26 PBDEs congeners. The highest concentrations of sigma26 PBDEs and BDE209 were detected in the sediment samples collected from Long River, with geometric mean of 146.07 and 502.63 pg x g(-1), respectively. A significant correlation was found between sigma26 PBDEs and BDE209, indicating that they might have the same pollution source. The concentrations of sigma26 PBDEs and BDE209 in the sediment were in the same order of magnitude with those reported on background levels in sediments of remote lakes in other countries, which shows the toxic biological effects on aquatic biota and potential risk due to sigma26 PBDEs and BDE209 contamination in sediments are negligible.


Assuntos
Sedimentos Geológicos/química , Éteres Difenil Halogenados/análise , Poluentes Químicos da Água/análise , Abastecimento de Água , China , Monitoramento Ambiental , Rios
10.
Guang Pu Xue Yu Guang Pu Fen Xi ; 33(5): 1194-7, 2013 May.
Artigo em Chinês | MEDLINE | ID: mdl-23905317

RESUMO

The humic acid (HA) and nonhydrolyzable carbons (NHC) were isolated from three river sediment samples (1, 2, 3) from the rivers in the Tongzhou district of Beijing and four soil samples(4, 5, 6, and 7) from the surface soils in the vicinity area of Tianjin near Bohai Bay, respectively. The isolated HA and NHC fractions were also characterized using elementary analysis, X-ray photoelectron spectroscopy (XPS), solid state 13C cross-polarization and magic angle spinning nuclear magnetic resonance spectroscopy (13C NMR), and Fourier transformed infrared spectroscopy (FTIR). The results showed that NHC had lower H/ C and O/C atomic ratios than HA from the same source. The sum of surface O-containing groups accounted for 7.6%-10.7% and 40.9%-46.7% in NHC and HA samples, respectively. 13C NMR and FTIR spectra of the NHC samples revealed a large contribution of alkyl carbon and aryl carbon. In addition, the NHCs isolated from soils had higher content of aromatic carbon than the NHC form river sediments. Systematic characterization showed that the NHC samples were more condensed and hydrophobicity than the HA samples.

11.
Guang Pu Xue Yu Guang Pu Fen Xi ; 33(2): 434-7, 2013 Feb.
Artigo em Chinês | MEDLINE | ID: mdl-23697127

RESUMO

Thermo Scientific Gallery Automatic Discrete Analyzer is special for water analyzing, and can automatically run steps includeing sample and reagents dispensing, water blank, mixing and incubation, Colorimetric reading and data processing. This method refers to U.S. Environmental Protection Agency. The instrument has advantage in low sample and reagents consumption, sensitivity and repeatability; test process can be automatic, standardized and informationized, and is applicable to multitudinous sample testing in water qualities and environmental monitoring.


Assuntos
Monitoramento Ambiental/métodos , Nitratos/análise , Nitritos/análise , Qualidade da Água , Água/química
12.
Guang Pu Xue Yu Guang Pu Fen Xi ; 33(12): 3396-401, 2013 Dec.
Artigo em Chinês | MEDLINE | ID: mdl-24611410

RESUMO

Seldom monitored trace element concentrations in road dusts colleted from Shihezi City were studied. A total of 32 sampling stations were selected. The concentration of 10 seldom monitored trace elements (B, Be, Bi, Co, Ga, Li, Sb, Sn, T1, V) were determined. Their pollution degree and source identification were analyzed by using Geoaccumulation Index, correlation coefficient and principal factor analysis. The results indicated that the mean concentrations of Li, Be, B, V, Co, Ga, Sn, Sb, T1 and Bi were 24. 91, 1.68, 41. 11, 72. 66, 13. 58, 36. 26, 3.64, 3.37, 0. 42 and 0.52 mgkg-1, respectively. The mean concentrations of Li, T1, Co, Be, B, and V were lower than or similar to the soil background values of Xinjiang province. However, the mean concentrations of Ga, Sn, Sb and Bi were higher than the background values of Xijiang province and world soil. The results of Geoaccumulation Index indicated that the pollution degrees of Li, Be, B, V, Co, Ga and T1 were zero, and belonged to the category of non-pollution. However the pollution of Sb, Bi and Sn were considerably serious, and their pollution grades were 2, 1 and 1 respectively. The source of SMTEs in road dusts of Shihezi City was identified by multivariate statistics (principal component analysis and correlation analysis). The results showed that Sb, Co, T1 and Bi mainly originated from human activities, Li, Be, B, V represented natural sources, while Sn and Ga have the mixed sources of nature and human activities.

13.
Huan Jing Ke Xue ; 33(8): 2574-9, 2012 Aug.
Artigo em Chinês | MEDLINE | ID: mdl-23213875

RESUMO

Eighty-one surface water samples were collected from 3 tributaries of the Yangtze River in different periods. Contents of 28 PCB congeners in surface water samples were measured using Varian CP3800/300 GC-MS/MS technique. PCB8, 18, and 28 are the most predominant PCB congeners in the samples from tributaries. The measured level of PCBs in the samples from the Tuo river, downstream of Ouchi River and Songlihongdao tributary were 1.96-2.59 ng x L(-1), 1.84-2.54 ng x L(-1) and 1.52-2.38 ng x L(-1). The average concentrations of PCBs in the samples were lower than USEPA criterion continuous concentration (14 ng x L(-1)), which were also in the same order of magnitude of those reported with lower levels in European and American countries. The estimated cumulative cancer risk for the local residents who drink water from tributaries were 0.15 x 10(-7)-0.26 x 10(-7), which shows that cancer risk are negligible due to PCBs contamination in these samples.


Assuntos
Monitoramento Ambiental/métodos , Bifenilos Policlorados/análise , Poluentes Químicos da Água/análise , China , Saúde , Medição de Risco , Rios
14.
Huan Jing Ke Xue ; 33(8): 2580-5, 2012 Aug.
Artigo em Chinês | MEDLINE | ID: mdl-23213876

RESUMO

Forty-seven surface water samples were collected from the main stream and 22 tributaries in area of the Three Gorges Reservoir, 15 phenolic compounds in these samples were analyzed using GC/MS. The results showed that the concentrations of phenolic compounds in the samples from the main stream and tributaries were 52.47 ng x L(-1) and 87.99 ng x L(-1), respectively. The concentrations of non-chlorinated phenols were higher than those of chlorinated phenols in the main stream and tributaries, and so the non-chlorinated phenols were the predominant compounds in these surface water samples. Phenol, o-cresol and 2-nitrophenol were the predominant compounds accounted for 79.1%, 3.7% and 3.6% in the samples from the main stream, respectively. Phenol, o-cresol, 2,6-dichlorophenol and 2-nitrophenol were the main compounds accounted for 77.5%, 5.4%, 3.8% and 2.2% in the samples from the tributaries, respectively. As compared the concentrations of phenol and 2-nitrophenol with the standard limits in The National Environmental Health Risk List, the levels of phenol and 2-nitrophenol were much lower than the standard limits, suggesting negligible risk of phenol and 2-nitrophenol in these samples.


Assuntos
Monitoramento Ambiental/métodos , Fenóis/análise , Poluentes Químicos da Água/análise , China , Cresóis/análise , Nitrofenóis/análise , Fenol/análise , Chuva , Rios , Estações do Ano , Abastecimento de Água
15.
Water Sci Technol ; 65(12): 2118-24, 2012.
Artigo em Inglês | MEDLINE | ID: mdl-22643405

RESUMO

A geochemical study of Beijiang River sediments was carried out to analyze the concentrations, distribution, accumulation and potential sources of the seldom monitored trace elements (SMTEs: Sc, V, Co, Ga, Y, Sn and Sb). The mean concentrations of Sc, V, Co, Ga, Y, Sn and Sb were 8.2, 60.3, 9.6, 17.2, 28.6, 85.6 and 39.0 mg/kg, respectively. The concentrations of the SMTEs, together with their spatial distribution showed that the SMTEs were mainly due to anthropogenic inputs from the metal smelting industries and local mining activities in the upper region of the river. The assessment by geoaccumulation index indicates that Sc, V, Co, Ga and Y are at the unpolluted level, Sn is at the 'strongly contaminated' level, and Sb is at the 'extremely contaminated' level. The pollution level of the SMTEs is: Sb > Sn > Y > Ga > Co > V > Sc. The results of correlation analysis and principal component analysis indicated the Sn and Sb were positively correlated with each other, indicating a common source in sediments. In conclusion, our results indicate that the sediments in Beijiang River have been severely contaminated by Sn and Sb.


Assuntos
Monitoramento Ambiental , Sedimentos Geológicos/química , Oligoelementos/análise , Poluentes Químicos da Água/análise , China , Espectrometria de Massas
16.
Huan Jing Ke Xue ; 32(7): 2069-73, 2011 Jul.
Artigo em Chinês | MEDLINE | ID: mdl-21922832

RESUMO

Violent disturbance are occurring in Haihe River basin due to a large number of human activities. To investigate the PBDEs pollution status and their distribution character, 48 surface sediment samples (at the top 0-5 cm layer) were collected from 14 principal tributaries in Haihe River basin. The contents of 27 PBDEs congeners in sediments were measured using Varian CP3800/300 GC-MS/ MS technique. The measured level of PBDEs ranged from 0.06 to 2.10 ng g(-1), the highest concentrations of PBDEs were detected in the sediment samples from Tuhai River, with geometric mean 2.10 ng x g(-1). BDE184, 207, 197, 191, 183 and 156 were the most predominant PBDE congeners, with their concentrations accounting for 40% of the total PBDEs concentration observed in the samples. Whereas BDE15, 28 and 47 were the primary PBDE congeners in the sediments from other rivers, with their concentration accounted for over 22% of the total PBDEs concentration. The PBDEs levels monitored in the present study were compared to those reported recently for districts located in other countries. The concentrations of PBDEs in the sediment samples were in the same order of magnitude of those reported on background levels in remote lakes sediment in European and American countries, which shows low-level PBDEs contamination in sediments.


Assuntos
Sedimentos Geológicos/análise , Éteres Difenil Halogenados/análise , Poluentes Químicos da Água/análise , China , Monitoramento Ambiental , Água Doce/análise , Medição de Risco , Rios
17.
Huan Jing Ke Xue ; 32(3): 736-41, 2011 Mar.
Artigo em Chinês | MEDLINE | ID: mdl-21634172

RESUMO

In order to survey platinum group elements (PGEs) contamination in central urban area of Beijing, dust samples were collected from the second ring road in December 2009. The road samples were digested with aqua regia and separated and purified with cation exchange resin, and the resulting solutions were analyzed by inductively coupled plasma mass spectrometry (ICP-MS). The results showed that the concentrations of Pd, Pt and Rh in road dust ranged from 17.40-458.75 ng x g(-1) (126.66 ng x g(-1)), 10.04-182.89 ng x g(-1) (65.25 ng x g(-1)), 4.00-68.04 ng x g(-1) (22.67 ng x g(-1)) respectively. In comparison with international cities, Pd and Rh concentrations in Beijing road dust were middle level and Pt concentration was lower. Pd concentration was rapidly increased in recent years. The concentrations of PGEs in four locations of the second ring road were arranged in the following order: West approximately East > North > South, which were controlled with the traffic intensity. Size partitioning indicated that the 0.125-0.25 mm fraction had the higher PGEs concentrations than other fractions and the < 0.063 mm fraction had the lower PGEs concentration. These data suggest that autocatalyst PGEs flux estimates into the environment will be significantly underestimated if only a fine grain size fraction (< 0.063 mm) is analyzed.


Assuntos
Poeira/análise , Poluentes Ambientais/análise , Platina/análise , Emissões de Veículos/análise , China , Cidades , Monitoramento Ambiental
18.
Huan Jing Ke Xue ; 31(1): 111-6, 2010 Jan.
Artigo em Chinês | MEDLINE | ID: mdl-20329525

RESUMO

This paper assesses the potential of NanoChem zeolite for ammonia removal from synthetic solution and actual landfill leachate. The data from experiments in batch study were applied to Langmuir isotherm. The saturated amount of NH4(+) -N adsorbed per unit weight of NanoChem zeolite was about 364 mg x g(-1), which yield significantly 3-30 times higher ammonium adsorption capacity than nature zeolite and Microporous molecular sieves. The results of batch study showed that the contact time needed at least 20 h in order to attain exchange equilibrium; the ammonia removal capacity of NanoChem zeolite increased with the increase of initial ammonia concentration, while the ammonia removal rate decreased with the increase of initial ammonia concentration; the pH had an effect on ammonia removal efficiency as it can influence both the character of the exchanging ions and the NanoChem zeolite itself; regeneration made little change on ammonia removal efficiency, repeatability was good. In column study, the NanoChem zeolite was used for high ammonia nitrogen removal such as actual landfill leachate and the ammonia nitrogen was removed 100%.


Assuntos
Troca Iônica , Nanopartículas , Compostos de Amônio Quaternário/isolamento & purificação , Eliminação de Resíduos Líquidos/métodos , Zeolitas/química , Adsorção , Nitrogênio/isolamento & purificação
19.
Zhongguo Gu Shang ; 21(6): 453-4, 2008 Jun.
Artigo em Chinês | MEDLINE | ID: mdl-19108435

RESUMO

OBJECTIVE: To summarize and analyze the clinical indication, surgical techniques and results of percutaneous antegrade Kirschner pinning in the treatment of proximal fracture of humerus. METHODS: Thirty-two patients with displaced fractures of the proximal humerus were treated with 2 to 3 Kirschner wires by percutaneous antegrade transfixation. Among 32 casas, there were 7 male and 25 female, with a mean age of 49.25 years (range, from 28 to 75 years). According to the Neer fracture classification, there were 20 cases of 2-part, 9 of 3-part, and 3 of 4-part fractures. RESULTS: All patients were followed up for 8 to 34 months with an average of 13.5 months. According to Constant-Murley evaluation, the results were excellent in 21 cases, good in 9, fair in 2. CONCLUSION: Percutaneous antegrade transfixaton is a good technique for the management of displaced 2-part fractures of the proximal humerus and also alternative to 3-part or 4-part fractures.


Assuntos
Fios Ortopédicos , Fixação Interna de Fraturas/métodos , Fraturas do Úmero/cirurgia , Adulto , Idoso , Feminino , Humanos , Masculino , Pessoa de Meia-Idade
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA
...