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1.
The ozone in Rio de Janeiro has been in violation of national air quality standards. Among all of the monitoring stations, the Bangu neighbourhood has the most violations of the national standard of 160 μg m?3 for the years 2012 and 2013. This study evaluated the reactivity of the carbonyls and aromatics in the tropospheric ozone formation processes. The samples were collected between July and October of 2013. Carbonyls were sampled using SiO2 cartridges coated with C18 and impregnated with 2,4-dinitrophenylhydrazine and were analysed by HPLC. Activated carbon cartridges and GC/MS were used to measure the concentration of monoaromatic hydrocarbons. An air quality monitoring station provided the concentrations of the criteria pollutants and the meteorological parameters. Cluster analysis and a Pearson correlation matrix were used to determine the formation of groups and the correlation of the variables. The evaluation of the volatile organic compounds (VOC) reaction with OH radicals and the MIR scale was used to extrapolate the reactivity of VOCs to the ozone formation. The average concentrations obtained were 19.7 and 51.9 μg m?3 for formaldehyde and acetaldehyde, respectively. The mean concentrations obtained for aromatics were 1.5, 6.7, 1.5, 2.6 and 1.6 μg m?3 for benzene, toluene, ethyl benzene, m+p-xylene and o-xylene, respectively. The cluster analysis indicated the presence of three similar groups, with one formed by gaseous criteria pollutants, another formed by the meteorological parameters, ozone and fine particles, and the last group formed by the aromatics. For the two reactivity scales evaluated, acetaldehyde and toluene were the main ozone precursors.  相似文献   

2.
The increasing concern regarding the preservation of soil quality suggests the adoption of quality reference values as a first step in environmental monitoring actions. In this context, the objective of this study was to establish soil quality reference values for Al, Zn, Mn, Cd, Fe, Pb, Ni, Cr, and Cu and to correlate several soil properties with the occurrence of these elements in the hillslope region of Rio de Janeiro State. Sixty-two samples were collected at depths of 0–20 and 20–40 cm and analyzed using the USEPA method 3051A. After clustering analysis, the samples were separated into three groups. Classification functions were obtained based on the variables pH - Mg - Fe - Mn, i.e., the variables that were best related to heavy metal content. We determined to establish the quality reference values for the 75th percentile of the three groups. The relief forms of the area, which facilitate the transport of soil fine-particle fractions and accumulation in lowlands, were revealed to be one of most important factors in understanding the distribution of soil heavy metals.  相似文献   

3.
Rodrigo de Freitas Lagoon is an urban ecosystem undergoing accelerated degradation, therefore selected as a model for microbiological quality studies of tropical lagoons. The aim of this study was to evaluate the abundance and the spatial distribution of fecal pollution indicators and pathogenic microorganisms in the lagoon. The relationships between microbial groups and abiotic measurements were also determined to evaluate the influence of environmental conditions on bacterial distribution and to identify the capability of coliforms and Enterococcus to predict the occurrence of Vibrio, Staphylococcus aureus, and Salmonella. Surface water samples were collected monthly, from December 1999 to October 2000. Analyses were performed by traditional culture techniques. A uniform spatial distribution was observed for all bacterial groups. The fecal pollution indicators occurred in low abundances while potentially pathogenic microorganisms were consistently found. Therefore, our study supported the use of counts of coliforms and Enterococcus to indicate only recent fecal contamination.  相似文献   

4.
EIA has been instituted in developing countries in the last decade largely in response to outside pressures. Governments have been quick to initiate reforms rather than jeopardize projects that might be key to national development plans. At the subnational level, most projects are not financed by foreign aid. The application of EIA at this level is often the result of pressure exerted on policy elites by the bureaucracy. This paper describes the reorganization of environmental protection agencies in the state of Rio de Janeiro in Brazil. This reorganization provided the setting for a bureaucratic initiative on EIA. The authors also analyze two cases in which EIA was applied unsatisfactorily and comment on the political realites of implementing EIA at the subnational level.  相似文献   

5.
The Oswaldo Cruz Foundation Campus (FIOCRUZ), in a suburban region of the city of Rio de Janeiro, was selected as a case study to assess the pollution released from vehicle and industrial facilities in Basin III, the most polluted area of the city. Concentrations of particulate matter (PM10) and trace metals in airborne particles were determined in an intensive field campaign. The samplings were performed every six days for 24 h periods, using a PM10 high volume sampler, from September 2004 to August 2005. PM10 mass concentrations were determined gravimetrically and the metals by ICP-OES. For PM10, the arithmetic mean for the period is 169 ± 42 μg m−3 which is 3.4 times the national recommended standard of 50 μg m−3. Additionally, 51% of the samplings exceeded the recommended 24 h limit of 150 μg m−3. Ca, Mg, Fe, Zn and Al were the metals that presented the higher concentrations. The correlation matrix gave two main clusters and three significant principal components (PC). Both PC1 and PC2 are associated to crustal, vehicular and industrial emissions while PC3 is mainly associated to geological material. Enrichment factors for Zn, Cu, Cd and Pb indicate that for these elements, anthropic sources prevail over natural inputs. PM10 levels showed a good correlation with hospital admissions for respiratory diseases in children and elderly people.  相似文献   

6.
Based upon several years of experience in investigations with macrozoobenthos in rivers in the states of Minas Gerais and Rio de Janeiro, a biological assessment system has been developed to indicate pollution levels caused by easily degradable organic substances from sewers. The biotic index presented here is aimed at determining water’s saprobic levels and was, therefore, named the “Saprobic Index for Brazilian Rivers in Minas Gerais and Rio de Janeiro states” (ISMR). For this purpose, saprobic valences and weights have been established for 122 taxa of tropical macrozoobenthos. Investigations were carried out in little, medium sized and big rivers in mountains and plains. Through ISMR, a classification of water quality and the respective cartographic representation can be obtained. Data collection and treatment methods, as well as the limitations of the biotic index, are thoroughly described. ISMR can also be used as an element to establish complex multimetric indexes intended for an ecological integrity assessment, where it is essential to indicate organic pollution.  相似文献   

7.
This work discusses the temporal variation of metal concentrations in a hypertrophic coastal lagoon located in the metropolitan area of Rio de Janeiro (Brazil). The lagoon watershed includes one of the mostly densely urbanized areas of the city but without industrial activities. Six sediment cores were collected in the lagoon between May and July 2003 and analyzed for the concentration of metals (Fe, Al, Mn, Zn, Pb, Cu, Cr, and Ni). Typical sedimentation rate was calculated as being 0.75 cm year???1 and was uniform for at least the past 70 years. Therefore, the alterations in the dynamics of the lagoon caused by changes in its watershed were clearly indicated in sediment cores. The construction of an artificial canal to the sea and the increasing urbanization and soil use changes were the major factors affecting metal accumulation in the lagoon sediments. Metals typical of anthropogenic urban sources (Pb, Zn, and Cu) showed increasing loads following urbanization.  相似文献   

8.
The orthotidal rivers are a new concept referring to inland rivers influenced by gravitational tides through the groundwater tides. “Orthotidal signals” is intended to describe tidal signals found in inland streamwaters (with no oceanic input); these tidal signals were locally generated and then exported into streamwaters. Here, we show that orthotidal signals can be found in proglacial rivers due to the gravitational tides affecting the glaciers and their surrounding areas. The gravitational tides act on glacier through earth and atmospheric tides, while the subglacial water is affected in a manner similar to the groundwater tides. We used the wavelet analysis in order to find tidally affected streamwaters. T_TIDE analyses were performed for discovering the tidal constituents. Tidal components with 0.95 confidence level are as follows: O1, PI1, P1, S1, K1, PSI1, M2, T2, S2, K2, and MSf. The amplitude of the diurnal tidal constituents is strongly influenced by the daily thermal cycle. The average amplitude of the semidiurnal tidal constituents is less altered and ranges from 0.0007 to 0.0969 m. The lunisolar synodic fortnightly oscillation, found in the time series of the studied river gauges, is a useful signal for detecting orthotidal rivers when using noisier data. The knowledge of the orthotidal oscillations is useful for modeling fine resolution changes in rivers.  相似文献   

9.
10.
Mercury (Hg) is considered a global pollutant, and the scientific community has shown great concern about its toxicity as it may affect the biota of entire systems, through bioaccumulation and bioamplification processes of its organic form, methylmercury (MeHg), along food web. However, few research studies deal with bioaccumulation of Hg from marine primary producers and the first-order consumers. So, this study aims to determine Hg distribution and concentration levels in phytoplankton and zooplankton in the Cabo Frio Bay, Brazil, a site influenced by coastal upwelling. The results from Hg speciation analyses show that inorganic mercury Hg(II) was the predominant specie in plankton from this bay. The annual Hg species distribution in plankton shown mean concentration of 2.00?±?1.28 ng Hg(II)?g?1 and 0.15?±?0.08 ng MeHg g?1 wet weight (phytoplankton) and 2.5?±?2.03 ng Hg(II)?g?1 and 0.25?±?0.09 ng MeHg g?1 wet weight (zooplankton). Therefore, upwelling zones should be considered in the Hg biogeochemical cycle models as a process that enhances Hg(II) bioaccumulation in plankton, raising its bioavailability and shelf deposition.  相似文献   

11.
自动监测技术在污染物总量控制监测上的应用   总被引:9,自引:0,他引:9  
为配合<"九五"期间全国主要污染物排放总量控制计划>的实施,中国环境监测总站与燕化公司环境保护监测站合作,在燕化公司某化工厂排放口设立了水污染物总量控制自动监测技术示范工程.该示范工程采用在线流量计、pH计、COD仪、油监测仪、采样器等监测设备和技术,对水污染物在线自动监测技术进行了多方面的试验,为实施水污染物总量控制的在线自动监测提供了经验.  相似文献   

12.
Heavy metal contamination in surface sediments of the Jiaozhou Bay was investigated in this study. Sediment sample was collected from the Jiaozhou Bay and its rivers. Heavy metal concentration was determined by inductively coupled plasma atomic emission spectroscopy and graphite furnace atomic absorption spectrometry. The result shows that river sediment in the east coast of the Jiaozhou Bay was heavily polluted especially for the Cu, Pb, Cd, and Zn. A slightly increase of heavy metal concentration was observed at stations near the east coast in the Jiaozhou Bay; however, contaminated sediment from polluted river was constrained mostly near shore within 3–4 km. Downstream decrease of heavy metals in river mouth suggested dilution from strong tidal current. Rapid seaward decline in the east coast and alongshore band dispersal pattern of heavy metals in surface sediment indicated mixing and remobilizing enhanced by large tidal range that regulated dispersal of sediments and anthropogenic heavy metals in the Jiaozhou Bay area.  相似文献   

13.
National parks are used worldwide as a means to protect the ecological integrity of unique ecosystems. Dilek National Park in western Turkey is a protected habitat for several endangered and severely threatened species. Thirty-seven water and 59 sediment samples were collected and analyzed for pesticides at two different sampling depths. The park is contaminated with 16 different organochlorine pesticides, with more pesticides detected in sediments than in water. The most prevalent pesticides in the 30–60-cm depth were DDT (69.5% of the samples), heptachlor (62.3%), a-endosulfan (55% of samples), and endrin (37%). Lindane isomers were present, but at <30% of the sediment samples. These pesticides could be a long-term contamination source that enters the food web used by the very species the park is trying to protect.  相似文献   

14.
The concentration of dissolved reactive phosphorus (DRP) in rivers can change intermittently within minutes depending on the weather and water discharge (Q), or activities in the watershed. Accordingly, accurate estimation of the annual DRP load requires frequent sampling or even continuous monitoring, which is laborious and cost-intensive. We present the design and laboratory evaluation of a new, robust, low-cost, low-tech device based on passive samplers (P-traps). The traps use Fe-(oxy)hydroxide coated quartz sand as an adsorbent enclosed in a vertical grid of individual cells separated from the river water by filter membranes. They are inexpensive, easy to handle, resistant to repeated desiccation and immersion and exposable for several months. They permit estimation of discharge dependent time weighted average DRP concentrations (C-Q relationships) and annual P loads of rivers characterized by highly variable DRP concentrations with a relative accuracy of +/- 3%.  相似文献   

15.
16.
This long-term study, performed during the years 2003–2005 and 2008–2009, investigated the carbon (C), nitrogen (N), and phosphorus (P) contents of the phyto- and zooplankton communities and the nutrient regime of Cabo Frio Bay, SE Brazil. The information intends to serve as baseline of the plankton C, N, and P stoichiometry for the calibration of biogeochemical and ecological models in support to future findings related to the local and regional phenomena of climatic change. Cabo Frio Bay is a small semienclosed system set adjacent to a region subject to sporadic coastal upwelling. Zooplankton exhibited average annual C, N, and P contents of 11.6?±?6.9 %, 2.8?±?1.8 %, and 0.18?±?0.08 %, and phytoplankton (>20 μm) 6.8?±?6.0 %, 1.6?±?1.5 %, and 0.09?±?0.08 %, respectively. The C/N/P ratios correspond to the lowest already found to date for a marine environment. The low C contents must have been brought about by a predominance of gelatinous zooplankton, like Doliolids/ Salps and also Pteropods. Average annual nutrient concentrations in the water were 0.21?±?0.1 μM for phosphate, 0.08?±?0.1 μM for nitrite, 0.74?±?1.6 μM for nitrate, and 1.27?±?1.1 μM for ammonium. N/P ratios were around 8:1 during the first study period and 12:1 during the second. The plankton C/N/P and N/P nutrient ratios and elemental concentrations suggest that the system was oligotrophic and nitrogen limited. The sporadic intrusions of upwelling waters during the first study period had no marked effect upon the systems metabolism, likely due to dilution effects and the short residence times of water of the bay.  相似文献   

17.
In this study, an analysis was performed on the concentrations of the trace elements Al, As, Ba, Cd, Co, Cr, Cu, Fe, Mn, Ni, Pb, V, and Zn in muscle of two carnivorous and one planktivorous fish species collected at Todos os Santos Bay (BTS). The accumulation order of the trace elements in Lutjanus analis was Al >Zn >Fe >Cr >Ba >Ni. In Cetengraulis edentulus, the order was Al >Fe >Zn >Cr >Ni >Mn >As. In the species Diapterus rhombeus, the order was Al >Fe >Zn >Cr >Ni >Mn >Cd. To determine the risk related to the consumption of fish, toxicity guidelines were used as standard references. It was observed that the species C. edentulus contained concentrations of As exceeding WHO limits, but these concentrations were acceptable according to the Agência Nacional de Vigilância Sanitária (ANVISA) guidelines. Cd levels were found only in D. rhombeus and in low concentrations according to the determinations of WHO and ANVISA. Pb levels were not detected in any of the three fish species. The analyzed elements did not differ statistically according to the species and feeding habits. The results point to possible risks of human contamination by As related to the consumption of the fish species C. edentulus from the BTS.  相似文献   

18.
The global cycles of man-produced pollutants entering the natural environment are reflected in changes of pollutant cycles, even in background regions.The system of mathematical balance simulation models of inorganic pollutant distribution and circulation (some heavy metals and pesticides included in the priority list for integrated background monitoring) has been developed for the Lake Baikal drainage basin. The system consists of the following units: (1) inventory and classification of regional sources of pollutants entering the atmosphere, natural waters and soils; (2) computation of the global atmospheric transfer and depositions; (3) regional spreading with atmospheric fluxes and deposition onto the underlying surfaces; (4) transport with waterflows feeding Lake Baikal; (5) transport with the lake currents and balance in the lake.The models developed have enabled improvement of existing programmes and systems of observations, in particular to substantiate the large-scale snow sampling and analysis network, and to develop the programme of integrated surveys of the state of Lake Baikal. Since 1981 these actions have been included in the operational network observations within the Lake Baikal Monitoring System.  相似文献   

19.
20.
Coastal shrimp farming may lead to the contamination of sediments of surrounding estuarine and marine ecosystems as shrimp farm effluent often contains high levels of pollutants including a range of organic compounds (from uneaten feed, shrimp feces, and living and dead organisms) which can accumulate in the sediments of receiving waterways. The assessment and monitoring of sediment quality in tidal creeks receiving shrimp farm effluent can support environmental protection and decision making for sustainable development in coastal areas since sediment quality often shows essential information on long-term aquatic ecosystem health. Within this context, this paper investigates nutrient loadings in the sediments of tidal creeks receiving shrimp farm effluent in Quang Ninh, Vietnam, which now have a high concentration of intensive and semi-intensive shrimp farms. Sediment samples taken from inside creek sections directly receiving effluent from concentrated shrimp farms (IEC), from main creeks adjacent to points of effluent discharge outside concentrated shrimp farms (OEC), and few kilometers away from shrimp farms (ASF) as reference sites were collected and analyzed before and after shrimp crops to investigate spatial and temporal variation. The results showed that there were statistically significant differences in the concentrations of total nitrogen, total phosphorus, and total organic carbon among IEC, OEC, and ASF sites while the seasonal variation being limited over study times. A sediment nutrient index (SNI) computed from coefficient scores of the factor analysis efficiently summarizes sediment nutrient loads, which are high, albeit quite variable, in canals directly receiving effluents from farms but then decline sharply with distance from shrimp farms. The visualization and monitoring of sediment quality data including SNI on maps can strongly support managers to manage eutrophication at concentrated shrimp farming areas, contributing to sustainable development and management at coastal zones.  相似文献   

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