RESUMO
Sulforaphane (SFN) is an organic isothiocyanate and an NF-E2-related factor-2 (Nrf2) inducer that exerts prophylactic effects on depression-like behavior in mice. However, the underlying mechanisms remain poorly understood. Brain-derived neurotrophic factor (BDNF), a neurotrophin, is widely accepted for its antidepressant effects and role in stress resilience. Here, we show that SFN confers stress resilience via BDNF upregulation and changes in abnormal dendritic spine morphology in stressed mice, which is accompanied by rectifying the irregular levels of inflammatory cytokines. Mechanistic studies demonstrated that SFN activated Nrf2 to promote BDNF transcription by binding to the exon I promoter, which is associated with increased Nrf2, and decreased methyl-CpG binding protein-2 (MeCP2), a transcriptional suppressor of BDNF, in BV2 microglial cells. Furthermore, SFN inhibited the pro-inflammatory phenotype and activated the anti-inflammatory phenotype of microglia, which was associated with increased Nrf2 and decreased MeCP2 expression in microglia of stressed mice. Hence, our findings support that Nrf2 induces BDNF transcription via upregulation of Nrf2 and downregulation of MeCP2 in microglia, which is associated with changes in the morphology of damaged dendritic spines in stressed mice. Meanwhile, the data presented here provide evidence for the application of SFN as a candidate for the prevention and intervention of depression.
Assuntos
Fator Neurotrófico Derivado do Encéfalo , Microglia , Animais , Anti-Inflamatórios/farmacologia , Fator Neurotrófico Derivado do Encéfalo/genética , Fator Neurotrófico Derivado do Encéfalo/metabolismo , Isotiocianatos/farmacologia , Isotiocianatos/uso terapêutico , Camundongos , Fator 2 Relacionado a NF-E2/genética , Fator 2 Relacionado a NF-E2/metabolismo , SulfóxidosRESUMO
OBJECTIVE: To evaluate the diagnostic value of interleukin 6 for neonatal sepsis. METHODS: The databases of CNKI, VIP, Wangfang, Pubmed, Embase, Web of Science, Cochrane Library were searched (by September 2014) to identify relevantly published studies about estimating the diagnostic value of interleukin 6 for neonatal sepsis. QUADAS tools were used for quality evaluation of the studies. A Meta analysis was performed by employing Meta Disc 1.4 and Stata11.0 software. Heterogeneity of the included articles was tested to select proper efficacy model for calculating pooled weighted sensitivity, specificity and 95%CI. Summary receiver operating characteristic (SROC) curve was made and the area under the curve and Q(*) index were calculated. RESULTS: A total of 33 studies including 3 135 neonates were enrolled. The sensitivity and specificity of interleukin 6 for the diagnosis of neonatal sepsis were 0.79 (95%CI: 0.76-0.81) and 0.83 (95%CI: 0.81-0.85) respectively. The area under SROC curve of interleukin 6 for the diagnosis of neonatal sepsis was 0.89 and Q(*) index was 0.83. The post-test probability of diagnosing neonatal sepsis indicated by negative interleukin 6 was 5%, while that of positive interleukin 6 was 60%. CONCLUSIONS: Interleukin 6 measurement is useful for the diagnosis of neonatal sepsis with a high sensitivity and specificity.
Assuntos
Interleucina-6/sangue , Sepse/imunologia , Humanos , Recém-Nascido , Curva ROC , Sensibilidade e Especificidade , Sepse/diagnósticoRESUMO
The allelic frequencies of apolipoprotein E (apoE) vary substantially around the world. There is a conspicuous south-to-north gradient of e4 frequencies in Europe, with the proportion of e4 carriers from only 10-15% in the south to 40-50% in the north. The mechanism may be related to the possibility that e4 carriers are less likely to develop vitamin D deficiency. In addition, Asian populations traditionally have lower e4 frequency than Europeans, which may be attributed in part to the scarce or irregular food supplies in Western world in the recent past. However, whether these geographical distribution gradients exist in China is yet unknown. ApoE genotypes of 200 children from Nanning City were determined by PCR-restriction fragment length polymorphism (RFLP) analysis. Allele frequency data of 18 other populations were collected from published sources and correlated with latitude and longitude information from different geographic resources. In our subjects, the frequencies of apoE genotypes were E3/E3: 73.0%, E3/E2: 15.0%, E4/E3: 5.0%, E4/E4: 5.0%, and E4/E2: 2.0%; the frequencies of apoE alleles were e2: 8.5%, e3: 83.0%, and e4: 8.5%, respectively. The total sample consisted of 3,679 individuals from 19 Chinese populations; the allelic frequencies were e2: 7.6%, e3: 85.5%, and e4: 6.9%, respectively; the proportion of e4 carriers was from 4.9% in Kunming to 17.5% in Harbin. Systemic comparison among multiple Chinese populations revealed that positive correlation existed between the e4 allele frequency distribution and latitude north (r=0.586, P=0.008), but no correlation of the e4 allele frequency distribution with longitude east was found (r=-0.018, P=0.942). We conclude that there is a south-to-north, but not an east-to-west gradient for the apoE4 allele in China.
Assuntos
Alelos , Apolipoproteína E4/genética , Povo Asiático/genética , Genética Populacional , Geografia , Adolescente , Criança , Pré-Escolar , China , Etnicidade/genética , Feminino , Frequência do Gene/genética , Genótipo , Humanos , MasculinoRESUMO
The soil and water assessment tool (SWAT) model is currently one of the most widely used watershed models in China. Since the model has been developed with distributed parameters and is customized to satisfy the environmental characteristics of the U.S.A., determining appropriate parameter values that reflect local features for model application in China is crucial. Some studies have proposed parameter values for the SWAT model by summarizing reported values in the literature; however, these studies neither differentiate the literature with respect to its quality nor consider non-uniformity in parameter values and the impact of extreme values. To address this, an indicator system for assessing the quality of SWAT model research was established, taking into account the process of model development, parameter calibration, and model validation as well as model performance. This screening approach was applied to a total of 428 journal articles on SWAT model research published between 2015 and 2017 were retrieved from the China National Knowledge Infrastructure database. The reported values of 15 model parameters involved in hydrology and sediment and nutrient simulation were extracted from highly credible articles and analysed in terms of statistical distributions, differences among geographic regions, and discrepancies between calibrated and default values. Results showed that the 129 highly credible journal articles screened generally followed good modelling practice and consisted of case studies from different regions across China. The statistical distributions of the 15 model parameters derived from the SWAT model studies exhibited a range of features including positive and negative skewness, and those of 4 parameters showed significant differences among regions where the watersheds are located. Furthermore, the calibrated values of 12 out of 15 parameters were significantly different from their default values. Considering the statistical characteristics of these model parameters, recommended parameter values for SWAT model application in China are proposed in the form of confidence intervals, and specific suggestions are also provided based on data availability.
RESUMO
Hyperlipidemia (HLP), a common complication, is very prevalent in children with primary nephrotic syndrome (PNS). HLP not only significantly increases the cardiovascular risk in adulthood, but also accelerates the progression of renal disease. Proteinuria as the most important pathophysiological change can reduce serum colloid osmotic pressure, which leads to an increase in the synthesis of serum proteins including lipoproteins in the liver for export to the serum. Thus, the severity of lipid abnormalities may correlate with the degree of proteinuria. A total of 378 children with PNS were divided into three groups according to their urinary protein excretion (UPE), group A (50 mg/kg/d < or = proteinuria <100 mg/kg/d, 125 cases), group B (100 mg/kg/d < or = proteinuria <200 mg/kg/d, 132 cases) and group C (proteinuria > or =200 mg/kg/d, 121 cases). In addition, 200 healthy volunteers with neither allergic nor renal disease between 3 and 14 years of age were recruited as the control group. Fasting serum levels of lipoprotein (a) [Lp(a)], total cholesterol (TC), triglyceride (TG), high density lipoprotein cholesterol (HDL-C), apolipoprotein A1 (apoA1), apoB, and albumin (Alb) were measured. Serum low density lipoprotein cholesterol (LDL-C) was calculated by the Friedewald formula. As expected, when all patients were compared with healthy children in this study, UPE and the serum concentrations of Lp(a), TC, TG, HDL-C, LDL-C, and apoB were higher in the PNS than in the control group (p<0.01), whereas for apoA1/B ratio the opposite was observed (p<0.01). Furthermore, patients in group C exhibited significantly higher Lp(a), TC, TG, LDL-C, and apoB concentrations than those in group A or B (p<0.01), whereas for apoA1/B ratio the opposite was found (p<0.01). The increase in serum lipids was accompanied by a significant augmented UPE in all patients (p<0.05). More specifically, positive correlations were observed between serum levels of TC (r=+0.80, p<0.01), HDL (r=+0.49, p<0.01), LDL (r=+0.79, p<0.01), ApoB (r=+0.62, p<0.01) and log proteinuria in group B; additionally, a negative correlation was observed between apoA1/B ratio and log proteinuria in group B (r=-0.38, p<0.01). However, no correlation of serum lipid profiles with UPE was determined in group A and C, respectively (p>0.05). Serum Alb was negatively correlated with Lp(a) (r=-0.96, p<0.01), TC (r=-0.78, p<0.01), TG (r=-0.78, p<0.01), LDL-C (r=-0.88, p<0.01), apoA1 (r=-0.26, p<0.01), and apoB (r=-0.71, p<0.01), while positively correlated with apoA1/B (r=+0.27, p<0.01) in all nephrotic children. Furthermore, no correlation existed between serum lipid profiles and Alb in group A, B and C, respectively (p>0.05). In Conclusion, secondary dyslipidemia in children with PNS is in parallel with the degree of UPE. There are diverse characteristics of lipid metabolism under different UPE. As for the patients with medium-UPE, positive correlation between serum lipids and proteinuria is presented.
Assuntos
Metabolismo dos Lipídeos , Síndrome Nefrótica/complicações , Síndrome Nefrótica/metabolismo , Proteinúria/complicações , Proteinúria/metabolismo , Adolescente , Estudos de Casos e Controles , Criança , Feminino , Humanos , Lipídeos/sangue , Masculino , Síndrome Nefrótica/sangue , Síndrome Nefrótica/urina , Proteinúria/sangue , Proteinúria/urina , Albumina Sérica/metabolismoRESUMO
BACKGROUND: Some studies have demonstrated that genetic variance of apolipoprotein B (APOB) plays an important role in lipid metabolism in childhood. However, little information exists about the distribution and effect of the APOB polymorphism among the population from Guangxi, where populations have developed through complex interaction among various ethnic groups over the centuries. The purpose of this study was to investigate the association of genetic polymorphisms at the APOB XbaI, EcoRI and MspI restriction sites with body mass index (BMI), serum protein and lipid profiles in children of Guangxi. METHODS: Genomic DNA was extracted from 200 healthy children from Guangxi. APOB XbaI, EcoRI and MspI genotypes were determined by PCR-restriction fragment length polymorphism (RFLP) analysis. BMI was evaluated. Fasting serum levels of total protein (TP), albumin (Alb), globulin (Glo), lipoprotein (a) [Lp(a)], total cholesterol (TC), triglyceride (TG), high density lipoprotein cholesterol (HDL-C), low density lipoprotein cholesterol (LDL-C), apolipoprotein A1 (apoA1) and apoB were measured. RESULTS: Subjects with X+ allele exhibited significantly higher BMI, and serum levels of Lp(a), TC, TG, LDL-C and apoB than those with X- allele (p<0.05), whereas for TP and Alb the opposite were found (p<0.05). E - /E- carriers had significantly higher Lp(a), TC, HDL-C, and apoA1 concentrations than did E + /E- or E + /E+ (p<0.05), whereas for TP and Alb the opposite were found (p<0.05). Higher Lp(a), TC, HDL-C, and lower TP, Alb concentrations were observed in individuals with E- allele as compared to E+ allele (p<0.05). No significant differences in BMI, serum protein and lipid parameters were determined for the polymorphism study of the APOB MspI locus (p>0 0.05). CONCLUSIONS: APOB XbaI and EcoRI restriction sites may serve as potential genetic markers affecting BMI, serum protein and lipid profiles in children from Guangxi. Living habits and diet should be modified, according to the genetic polymorphism of APOB. In addition, because the groups of rare allele carriers of XbaI and MspI polymorphisms are very small, the significance of the statistical analysis may be weak.
Assuntos
Apolipoproteínas B/sangue , Apolipoproteínas B/genética , Povo Asiático/genética , Índice de Massa Corporal , Polimorfismo de Nucleotídeo Único/genética , Adolescente , Alelos , Criança , Pré-Escolar , China , Feminino , Genótipo , Humanos , Masculino , Obesidade/genética , Reação em Cadeia da PolimeraseRESUMO
Characteristics of surface runoff from a 0.14-km2 urban catchment with separated sewer in Macau was investigated. Water quality measurements of surface runoff were carried out on five rainfall events during the period of August to November, 2005. Water quality parameters such as pH, turbidity, TSS, COD, TN, Zn, Pb, and Cu were analyzed. The results show that TN and COD are the major pollutants from surface runoff with mean concentration of 8.5 and 201.4 mg/L, both over 4-fold higher compared to the Class V surface water quality standard developed by China SEPA. Event mean concentration (EMC) for major pollutants showed considerable variations between rainfall events. The largest rainfall event with the longest length of antecedent dry weather period (ADWP) produced the highest EMC of TN, TSS and COD. From the pollutographs analysis, the peak concentration of TN precedes the peak runoff flow rate for all three rainfall events. The tendency of the concentration of TSS, turbidity and COD changing with runoff flow varies between rainfall events. The relationship between TSS and other parameters were analyzed to evaluate the efficiency of the physical treatment process to control the surface runoff in the urban catchment. Based on the correlation of parameters with TSS, high treatment efficiency of TSS, TN and COD was expected. The most significant event in term of first flush is the one with the strongest rainfall intensity and longest length of ADWP. TN always showed first flush phenomenon in all three rainfall events, which suggested that the surface runoff in the early stage of surface runoff should be dealt with for controlling TN losses during rainfall events.
Assuntos
Nitrogênio/análise , Chuva , Poluentes Químicos da Água/análise , Cidades , Macau , Metais Pesados/análise , Clima Tropical , Movimentos da Água , Abastecimento de ÁguaRESUMO
OBJECTIVE: To assess a simple and non-invasive scoring system, osteoporosis self-assessment tool for Asians (OSTA) and quantitative ultrasound (QUS) measurement to identify Chinese postmenopausal women with non-vertebral fracture. METHODS: Data came from 513 healthy women. Speed of sound (SOS) of the radius, phalanx and tibia was assessed using the instrument of Omniscience (Sunlight Ltd. Israel). Body height and weight were measured. Body mass index and OSTA were calculated. Self-reported fractures were identified using a structured questionnaire. RESULTS: SOS of radius was significantly lower in women with non-vertebral fracture than those without. SOS of phalanx was significantly lower in women with a history of postmenopausal non-vertebral fracture than those without. Using cut-offs of OSTA -4 and -1 to categorize osteoporosis risk, SOS of radius, phalanx and tibia decreased with increasing risk, while the prevalence of non-vertebral fracture increased. OSTA values of Assuntos
Fraturas Ósseas/diagnóstico
, Osteoporose Pós-Menopausa/diagnóstico
, Adolescente
, Adulto
, Idoso
, Idoso de 80 Anos ou mais
, Índice de Massa Corporal
, Densidade Óssea
, Estudos Transversais
, Feminino
, Fraturas Ósseas/diagnóstico por imagem
, Fraturas Ósseas/etiologia
, Humanos
, Programas de Rastreamento
, Pessoa de Meia-Idade
, Osteoporose Pós-Menopausa/diagnóstico por imagem
, Inquéritos e Questionários
, Ultrassonografia
RESUMO
Nonylphenol (NP) was quantified using liquid chromatography tandem mass spectrometry (LC-MS/MS) in the urine and plasma of rats treated with 0, 50, and 250 mg/kg/day of NP for four consecutive days. A urinary metabolomic strategy was originally implemented by high performance liquid chromatography time of flight mass spectrometry (HPLC-QTOF-MS) to explore the toxicological effects of NP and determine the overall alterations in the metabolite profiles so as to find potential biomarkers. It is essential to point out that from the observation, the metabolic data were clearly clustered and separated for the three groups. To further identify differentiated metabolites, multivariate analysis, including principal component analysis (PCA), orthogonal partial least-squares discriminant analysis (OPLS-DA), high-resolution MS/MS analysis, as well as searches of Metlin and Massbank databases, were conducted on a series of metabolites between the control and dose groups. Finally, five metabolites, including glycine, glycerophosphocholine, 5-hydroxytryptamine, malonaldehyde (showing an upward trend), and tryptophan (showing a downward trend), were identified as the potential urinary biomarkers of NP-induced toxicity. In order to validate the reliability of these potential biomarkers, an independent validation was performed by using the multiple reaction monitoring (MRM)-based targeted approach. The oxidative stress reflected by urinary 8-oxo-deoxyguanosine (8-oxodG) levels was elevated in individuals highly exposed to NP, supporting the hypothesis that mitochondrial dysfunction was a result of xenoestrogen accumulation. This study reveals a promising approach to find biomarkers to assist researchers in monitoring NP.
Assuntos
Fenóis/toxicidade , 8-Hidroxi-2'-Desoxiguanosina , Animais , Biomarcadores/sangue , Biomarcadores/urina , Cromatografia Líquida de Alta Pressão/métodos , Desoxiguanosina/análogos & derivados , Desoxiguanosina/urina , Análise Discriminante , Feminino , Glicerilfosforilcolina/urina , Glicina/urina , Análise dos Mínimos Quadrados , Malondialdeído/urina , Espectrometria de Massas/métodos , Metabolômica , Análise Multivariada , Estresse Oxidativo/efeitos dos fármacos , Análise de Componente Principal , Ratos Sprague-Dawley , Reprodutibilidade dos Testes , Serotonina/urina , Triptofano/urinaRESUMO
Lake eutrophication has increasingly become a major environmental issue in China. Although significant efforts have been made towards its resolution in the last decade, most of the implemented control strategies are fragmented, and the formation of policy lacks of sound scientific basis and long-term objectives. Taking the well-known Dianchi Lake as a case study, this paper presented a comprehensive assessment for the effectiveness of various eutrophication control strategies. It is expected that the concluding lessons would have a major implication to future eutrophication control.
Assuntos
Meio Ambiente , Eutrofização , Poluição da Água/prevenção & controle , Agricultura , China , Engenharia , Indústrias , Eliminação de Resíduos LíquidosRESUMO
Thesis aims at evaluating and setting priority to human toxicity and ecotoxicity of coking pollutants. A field research and sampling project are conducted in coke plant in Shanxi so as to complete the coke emission inventory. The USEtox model representing recommended practice in LCIA characterization is applied to the emission inventory to quantify the potential impacts on human toxicity and ecotoxicity of emerging pollutants. Priority pollutants, production procedures and effects of changing plant site on the toxicity are analyzed. As conclusions, benzo(a) pyrene, benzene, Zn and As are identified as the priority pollutants in human toxicity, while pyrene and anthracene in ecotoxicity. Coal charging is the dominant procedure for organic toxicity and priority pollutants include benzo (a) pyrene, benzene, naphthalene, etc. While coke drenching is the dominant procedure for metal toxicity and priority pollutants include Zn, As, Ti, Hg etc. Emission to rural environment can reduce the organic toxicity significantly compared to the emission to urban environment. However, the site changing has no effect on metal toxicity and might increase the risk of the metal pollution to rural water and soil.
Assuntos
Coque , Poluentes Ambientais/toxicidade , Modelos Teóricos , Arsênio/toxicidade , Benzeno/toxicidade , Benzo(a)pireno/toxicidade , Carvão Mineral , Humanos , Indústrias , Zinco/toxicidadeRESUMO
Scenario analysis was used to study the environmental burden in a coastal city of Zhejiang province under different patterns of economic development. The aim of this research is to propose advices on decision making by illustrating how to make emissions reduced by transforming the pattern of economic development in a developed coastal area, which had acquired the level of 70 000 yuan GDP per cap. At first, 18 heavy pollution industries were screened out, by referencing total emissions of chemical oxygen demand, ammonia-nitrogen, sulfur dioxide, and nitrogen oxide. Then, a model of scenario analysis and the back-up calculation program were designed to study the sustainable development of the heavy pollution industries. With 2008 and 2015 as the reference year and the target year respectively, emissions of four pollutants mentioned above in the 18 heavy pollution industries in the city were analyzed under six scenarios. The total emissions of 4 pollutants should be reduced to an expectant degree, which is set as the constraint prerequisite of the scenario analysis. At last, some suggestions for decision-making are put forward, which include maintaining a moderate increase rate of GDP around 7%, strengthening the adjustment of economic structure, controlling the increasing rate of industrial added value of the industries with heavy pollution, optimizing the structure of industries with heavy pollution, decreasing the intensity of waste emission by implementing cleaner production to reduce emission produce at the source, and strengthening regulations on the operation of waste treatment plants to further promote the efficiency of waste treatment. Only by implementing such measures mentioned above, can the total emissions of chemical oxygen demand, ammonia-nitrogen, sulfur dioxide, and nitrogen oxide of the 18 industries with heavy pollution in the city be reduced by a 10%, 10%, 5%, and 15% respectively based on the reference year.
Assuntos
Poluição Ambiental/prevenção & controle , Resíduos Industriais/prevenção & controle , Técnicas de Planejamento , Gerenciamento de Resíduos , China , Cidades , Técnicas de Apoio para a Decisão , Poluição Ambiental/análise , Resíduos Industriais/análise , Modelos TeóricosRESUMO
An urban watershed in Xiamen was selected to perform the parameter uncertainty analysis for urban stormwater runoff modeling in terms of identification and sensitivity analysis based on storm water management model (SWMM) using Monte-Carlo sampling and regionalized sensitivity analysis (RSA) algorithm. Results show that Dstore-Imperv, Dstore-Perv and Curve Number (CN) are the identifiable parameters with larger K-S values in hydrological and hydraulic module, and the rank of K-S values in hydrological and hydraulic module is Dstore-Imperv > CN > Dstore-Perv > N-Perv > conductivity > Con-Mann > N-Imperv. With regards to water quality module, the parameters in exponent washoff model including Coefficient and Exponent and the Max. Buildup parameter of saturation buildup model in three land cover types are the identifiable parameters with the larger K-S values. In comparison, the K-S value of rate constant in three landuse/cover types is smaller than that of Max. Buildup, Coefficient and Exponent.
Assuntos
Monitoramento Ambiental/métodos , Modelos Teóricos , Chuva , Movimentos da Água , Algoritmos , China , Cidades , Simulação por Computador , Método de Monte Carlo , IncertezaRESUMO
An 11-month-old male infant was admitted to our hospital with fever, fussiness, poor feeding, vomiting, and tachypnea for two days prior. Physical examination revealed sporadic papules and vesicles occurring on his hands, feet, face, and perianal mucosa. Enterovirus 71 was identified from both throat swab and vesicle fluid using virus isolation techniques. The patient's heart rate fluctuated in a very narrow range from 180~210/beats/min regardless of his physiologic state. An electrocardiogram showed P-waves buried within or occurring just after regular, narrow, QRS complexes. The patient was diagnosed as having hand, foot, and mouth disease in combination with paroxysmal supraventricular tachycardia (PSVT). The child recovered well with symptomatic treatment, including intravenous administration of acyclovir, glucocorticoids, immunoglobulin, adenosine, and sotalol. PSVT was terminated within 36 hours of hospitalization. The skin lesions became crusted on the third day, and then proceeded to heal spontaneously. Here we report on this unusual case and review the associated literature.
RESUMO
It is currently believed that melamine ingestion can lead to insoluble crystals in an animal's urinary system with subsequent physical obstruction or bladder carcinoma. However, whether melamine can cause injury of other tissues and organs in humans is yet unknown. In this study, we encountered 3 affected children with liver lesions, 2 males and 1 female, and detailed their clinical characterizations. Their ages were respectively 2, 6, and 10 months. Among the 3 patients with liver lesions, only 1 exhibited symptoms of gradual progressive jaundice, abdominal distention, hepatic intumesce, and bilirubin abnormality; the other 2 were asymptomatic. The mechanism associated with liver lesion may, at least in part, be due to physical deposition and blockage of the biliary tract system. Disturbance of the acid-base equilibrium may be another reason that accelerates stone formation in human tissues.
Assuntos
Hepatopatias/etiologia , Nefrolitíase/complicações , Triazinas/efeitos adversos , Alanina Transaminase/sangue , Aspartato Aminotransferases/sangue , Feminino , Humanos , Lactente , Icterícia/etiologia , Hepatopatias/complicações , Hepatopatias/diagnóstico , Masculino , Nefrolitíase/induzido quimicamente , Estudos RetrospectivosRESUMO
Sensitivity analysis of urban-runoff simulation is a crucial procedure for parameter identification and uncertainty analysis. Local sensitivity analysis using Morris screening method was carried out for urban rainfall runoff modelling based on Storm Water Management Model (SWMM). The results showed that Area, % Imperv and Dstore-Imperv are the most sensitive parameters for both total runoff volume and peak flow. Concerning total runoff volume, the sensitive indices of Area, % Imperv and Dstore-Imperv were 0.46-1.0, 0.61-1.0, -0.050(-) - 5.9, respectively; while with respect to peak runoff, they were 0.48-0.89, 0.59-0.83, 0(-) -9.6, respectively. In comparison, the most sensitive indices (Morris) for all parameters with regard to total runoff volume and peak flow appeared in the rainfall event with least rainfall; and less sensitive indices happened in the rainfall events with heavier rainfall. Furthermore, there is considerable variability in sensitive indices for each rainfall event. % Zero-Imperv's coefficient variations have the largest values among all parameters for total runoff volume and peak flow, namely 221.24% and 228.10%. On the contrary, the coefficient variations of conductivity among all parameters for both total runoff volume and peak flow are the smallest, namely 0.
Assuntos
Monitoramento Ambiental/métodos , Modelos Teóricos , Chuva/química , Movimentos da Água , Poluição da Água/análise , China , CidadesRESUMO
A comparative study on characteristics of stormwater runoff from two urban lawn catchments in Macau (ELH) and Xiamen (PGH) with separated sewer system were conducted. The result obtained shows that COD, TP and NO3- -N are the major pollutants with mean EMC of 165.77-60.48 mg/L, 0.96-0.44 mg/L and 7.16-1.18 mg/L, respectively, and the mean values of pollutants loads of COD, TP and NO3- -N from study lawn catchments are 6.53-0.63 kg/hm2, 0.0375-0.0047 kg/hm2 and 0.0122-0.0128 kg/hm2, respectively. Peak values of major pollutant concentrations usually precede the flow peak. First flush effect of rainfall runoff from two study catchments is no obvious, which can be reflected by the low mean value of FF30 of TSS, COD, TP and NO3- -N, with 36.26%, 26.13%, 28.13% and 39.03%, respectively. Based on multivariate statistical analysis, first flush effect from urban lawn rainfall runoff is greatly influenced by total rainfall amount (Tr) and total runoff volume (V).
Assuntos
Nitrogênio/análise , Compostos Orgânicos/análise , Poaceae/crescimento & desenvolvimento , Chuva , Poluentes Químicos da Água/análise , China , Cidades , Fósforo/análise , Movimentos da ÁguaRESUMO
The purpose of this paper is the application of storm water management model (SWMM) in simulating runoff hydrology and water quality. The study chose a roof as the typical impervious urban land surface, and monitored several rainfall-runoff events for parameter identification. We identified and validated hydrological and water quality parameters, using Monte Carlo sampling method and HSY algorithm, which are based on uncertainty analysis. Results show that impervious urban land surface runoff model includes 6 critical parameters, which are depression storage (S-imperv), Manning's n (N-imperv), maximum buildup possible (max buildup), buildup rate constant (rate constant), washoff coefficient (coefficient), and washoff exponent (exponent). Identification of S-imperv and N-imperv could use least square error as objectives, while others could use errors of event pollution load and peak concentration of pollutant as objectives. The identification results of the 6 parameters are N-imperv 0.012-0.025,S-imperv 0-0.7, max buildup 15-30,rate constant 0.2-0.8,coefficient 0.01-0.05, and exponent 1.0-1.2. Regional sensitivities of these parameters in non-ascending order are coefficient, S-imperv, N-imperv, max buildup, exponent, and rate constant. Identified parameters are able to be validated by SWMM model. However, current model structures still have some difficulties in simulating runoff pollutant concentration curves caused by some special rain patterns.
Assuntos
Modelos Teóricos , Chuva , Movimentos da Água , Poluentes da Água/análise , Algoritmos , China , CidadesRESUMO
The purpose of this study is identification and characterization of hydrological process of urban runoff, as well as concentration variation of pollutants in it. Samples were collected in 4 rainfall events in Beijing from Jun. 2006 to Aug. 2006. Hydrology and pollution of the rainfall-runoff process were analyzed on roof and road. Study results show that the shapes of hydrological curves of runoff, despite for a 5 - 20 min delay and a milder tendency, are similar to rainfall curves. Runoff coefficients of roof are 0.80 - 0.98, while 0.87 - 0.97 of road. Event mean concentrations (EMC) of pollutants are influenced by build-up and wash-off features, which leads to a higher concentration in road runoff than in roof runoff. Major pollutants that excess the water quality standards are COD, TN, and TP. Evident correlations (> 0.1) are found between pollutants. Correlation with particles are higher for COD and SO4(2-) (> 0.5), while lower for nutrients (<0.5). First flush effects (FFE) are found and affected by several factors, such as pollutant variety, types of land covers, and rainfall intensity. FFE are found more intense in SS, more frequently in road runoff, and more difficult to form for COD and nutrients with low rainfall intensity. Therefore, control of first period of runoff would be an effective approach for runoff management in Beijing.
Assuntos
Cidades , Chuva , Movimentos da Água , Poluentes Químicos da Água/análise , China , Monitoramento Ambiental , Modelos TeóricosRESUMO
Characteristics of pollutants from urban surface runoff were investigated. Two catchments with a seperated system in Macau were selected for sampling on rainfall events during the period of August to November, 2005. Water quality parameters such as pH, turbidity, TSS, COD, TOC, TN, TP, Zn, Pb, and Cu were analyzed. The results show that the commercial-residential urban catchment shows high level of COD, TN, TP, and the park urban catchment has high TN and TP concentration. From the pollutograph analysis, the peak of TSS, TN, TP concentration appears in the first and the third sample respectively in ELH and YLF catchments, and then the pollutants concentration tend to decrease. Regression analysis between TSS and TN & TP in two urban catchments resulted in a high value (R2 > 0.95) of the coefficient of determination R2 indicating a close relationship between soil losses and nitrogen & phosphorus discharged from surface runoff. The profile of TSS and COD discharged from surface runoff relates greatly to the surface flow change, whereas the surface flow change has little influence on the profile of TN and TP. The heavy metals such as Zn, Pb and Cu fluctuate with the continuous input of vehicles during rainfall events. Pollutants such as TSS, TN, COD discharged from surface runoff depend greatly on the dry periods and storms intensity in such two urban catchments.