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111.
Temporal trends of non-sea salt (nss-) sulfate and nitrate were analyzed from nationwide precipitation chemistry measurements provided by the Ministry of the Environment (MOE) for the 1988–2002 fiscal years (April–March). The concentrations and deposition of nss-sulfate were found to be decreasing, and those of nitrate were stable or slightly increasing at most sites. These deposition trends were discussed from the viewpoint of emissions of SO2 and NOX during the period of interest. Because monitoring techniques have changed in the number of active sites, samplers, and analytical methods during the operation period, the median of all annual depositions measured in Japan in a specific year was selected as the annual representative. The contribution of specific emission sources was also calculated for 1990 on the basis of the nss-sulfate and nitrate deposition in Japan obtained with a model simulation in which the model did not include volcanic emissions from Mt. Oyama, Miyakejima Island, which began to erupt suddenly and violently in 2000. For nss-sulfate, the calculated deposition agrees well with the intensity and trends of the median up to 1999. After 2000, a higher deposition than calculated in the preceding years was evident, which is attributable to the volcanic SO2 from Mt. Oyama. For nitrate, both the calculated and observed depositions were slightly increasing; however, the calculation was found to exceed the observation.  相似文献   
112.
基于不同测序技术的生物群落结构及功能菌分析   总被引:2,自引:0,他引:2  
分别采用克隆文库和高通量测序技术,解析生物去除铁锰氨滤池内微生物的群落结构和功能菌多样性,并探讨不同测序手段的差异.高通量测序获得15057条有效序列、共32个分类纲,克隆文库测序涵盖9个具有明确分类地位的纲(75条序列),前者能揭示更为丰富的细菌群落结构多样性.功能菌(铁锰氧化细菌和硝化细菌)分析过程中,一些功能菌属在克隆文库中出现,而在高通量测序中未检测到,反之亦然.与单一的测序手段相比,二者相结合能更好地揭示功能细菌的分布特点.  相似文献   
113.
Most fish farming waste output models provide gross waste rates as a function of stocked or produced biomass for a year or total culture cycle, but without contemplating the temporality of the discharges. This work aims to ascertain the temporal pattern of waste loads by coupling available growth and waste production models and developing simulation under real production rearing conditions, considering the overlapping of batches and management of stocks for three widely cultured species in the Mediterranean Sea: gilthead seabream (Sparus aurata), European seabass (Dicentrarchus labrax) and Atlantic bluefin tuna (Thunnus thynnus). For a similar annual biomass production, the simulations showed that waste output and temporal dumping patterns differ between the three species as a result of the disparities in growth velocity, nutrient digestibility, maintenance metabolic budget and husbandry. The simulations allowed the temporal patterns including the periods of maximum discharge and the dissolved and particulate nitrogen and phosphorus content in the wastes released to be determined, both of which were seen to be species-specific.  相似文献   
114.
Linking emissions trading schemes allows the combined emissions cap to be achieved at lower cost. Linking is usually environmentally neutral, but some design features can lead to higher aggregate emissions if schemes are linked. Technical solutions to limit the potential emissions increases due to design differences implemented when schemes are linked are not sufficient to ensure the environmental effectiveness of the linked schemes over time. Technological, economic, administrative and other changes that can lead to higher aggregate emissions are inevitable. The administrators of the linked schemes must ensure the stringency of the emissions cap relative to the “business as usual” emissions of affected sources, the accuracy of the emissions reported by affected sources, the integrity of the allowance registry, effective compliance enforcement, and the environmental integrity of the credits issued for emission reduction projects over time. This will require a process for agreeing on revisions to the regulations of the linked schemes, a mechanism to provide assurance of the environmental effectiveness of each of the linked schemes, and a procedure for terminating the linking agreement.
X. WangEmail:
  相似文献   
115.
These last decades, the Berre lagoon (in southeastern France) has been deeply affected since the 1930s by strong inputs of contaminants associated with industrial development and since 1966 by huge inputs of freshwater and silts due to the installation of a hydroelectric power plant. Surveys of the surface sediment contamination have been sparsely performed since 1964 for management and research purposes. These surveys were performed by various laboratories that investigated different chemicals and sampling areas using different analysis protocols. Therefore, the available data are disconnected in time and space and differ in quality. In order to reconstruct coherent time series of sediment contamination from this heterogeneous datasets and to discuss the influences of industrial and hydroelectric discharges we used a statistical approach. This approach is based on Principal Component Analysis (PCA) and Fuzzy clustering analysis on data from one extensive survey realized on surface sediments in 1976. The PCA allowed identifying two geochemical indexes describing the main surface sediment geochemical characteristics. The fuzzy clustering analysis on these indexes allowed identifying sub-areas under the specific influence of industrial or hydroelectric discharges. This allowed us to reconstruct, for each sub-area, a coherent and interpretable long-term time series of sediment contamination from the available database. Reconstructed temporal trends allowed us to estimate: (i) the overall decrease of sediment contamination since the mid-1970 attributed to industrial discharge regulations enacted at this period and (ii) the dilution of the concentrations of sediment bound contaminants induced by the hydroelectric power plant and its associated particulate matter inputs.  相似文献   
116.
综合水质标识指数法在浑河水质评价中的应用   总被引:12,自引:0,他引:12  
胡成  苏丹 《生态环境》2011,20(1):186-192
综合评价水环境质量,全面把握流域水环境污染特征是水环境污染防治中的重要基础性工作。水质标识指数可以完整标识水质评价指标的类别、水质数据、功能区目标值等重要信息,在单因子水质标识指数法基础上建立的综合水质标识指数法能完整表达河流总体的综合水质信息,既不会因个别水质指标较差就否定综合水质,又能对综合水质做出合理的评价;既可以在Ⅰ到Ⅴ类中比较水质的优劣,亦可以对劣Ⅴ类进行评价。为系统全面地研究浑河流域各不同河段水环境特征,将浑河流域划分为3个控制单元,根据2001—2010年间水质监测数据,采用综合水质标识指数法,识别出各控制单元主要污染因子,并阐明了浑河流域水环境质量时空变化规律,本研究即体现了全流域统筹考虑的系统思想,又体现了分区研究的针对性特点,并首次将综合水质标识指数法应用于浑河流域水质综合评价,其研究结论对水质监测数据的评价有一定的借鉴作用,亦对流域水污染防治对策的提出有一定的指导意义。  相似文献   
117.
The strict control measures and social lockdowns initiated to combat COVID-19 epidemic have had a notable impact on air pollutant concentrations. According to observation data obtained from the China National Environmental Monitoring Center, compared to levels in 2019, the average concentration of NO2 in early 2020 during COVID-19 epidemic has decreased by 53%, 50%, and 30% in Wuhan city, Hubei Province (Wuhan excluded), and China (Hubei excluded), respectively. Simultaneously, PM2.5 concentration has decreased by 35%, 29%, and 19% in Wuhan, Hubei (Wuhan excluded), and China (Hubei excluded), respectively. Less significant declines have also been found for SO2 and CO concentrations. We also analyzed the temporal variation and spatial distribution of air pollutant concentrations in China during COVID-19 epidemic. The decreases in PM2.5 and NO2 concentrations showed relatively consistent temporal variation and spatial distribution. These results support control of NOx to further reduce PM2.5 pollution in China. The concurrent decrease in NOx and PM2.5 concentrations resulted in an increase of O3 concentrations across China during COVID-19 epidemic, indicating that coordinated control of other pollutants is needed.  相似文献   
118.
119.
In order to investigate the applicability of 212Pb as a tracer for atmospheric transport in the sub-regional scale (few hundred kilometers in horizontal direction and up to ∼1 km by height), we measured the air concentrations of the short-lived radionuclide 212Pb along with the long-lived 7Be and 210Pb near the ground surface. For this purpose, simultaneous observations were continued for several days at three locations: a reference point representative for standard land surface atmosphere conditions, a second location at an altitude 650 m near the reference point, and on a solitary island ∼180 km from the reference point. Measurements of radioactivity in aerosol particle samples collected at intervals of 2-3 h with a high-volume air sampler were performed by extremely low background gamma-ray spectrometry with the use of Ge detectors located at the Ogoya Underground Laboratory. Concentration of 7Be or 210Pb and their variation patterns was found to be similar among the three points during the whole observation period except for moment of the passage of a cold front. The results indicate that distributions of concentrations of the long-lived nuclides were uniform in this range. On the other hand, concentration levels and the variation patterns of the short-lived 212Pb differed greatly from one location to another, reflecting differences in geographical location and altitude of the observation points. Additionally, there were certain indications that observed concentration of 212Pb contained two components: an autogenous component from sources nearby and a heterogenous one from faraway sources carried by atmospheric horizontal transport. Results of this study provide experimental proof that 212Pb can be used as a tracer of sub-regional atmospheric transport.  相似文献   
120.
The paper presents an approach for the interpretation of hydraulic tests of a CO2 storage reservoir. The sandstone reservoir is characterised by a fluviatile channel structure embedded in a low-permeability matrix. Pumping tests were carried out in three wells, with simultaneous pressure monitoring in each well.The hydraulic parameters (permeability and storativity) and the boundary configurations were calibrated using three different approaches: (i) parameter calibration and type curve interpretation for single-hole tests, (ii) calibration of the entire build-up phase for cross-hole tests, and (iii) calibration of the initial pressure response for cross-hole pumping tests. In addition, the arrival time of the pressure response was determined and provides additional information about the pathways of hydraulic connection.The measured pumping test permeabilities of the formation were much lower than those measured on the cores, which is very unusual. The pumping test permeabilities are mainly between 50 mD and 100 mD (millidarcy), while core samples show a mean aquifer permeability of 500–1100 mD. Based on this it was concluded that some kind of continuous low-permeability structure exists, which was supported by core material. Three possible aquifer configurations were considered. The first and second were derived from traditional pumping test analysis and were conceptualised using flow boundaries. Each of the analyses provides a different result. A method was developed in which these differences were resolved by interpreting the pressure response with respect to its spatial and temporal sensitivity. This solution lead to a third configuration which was mainly based on spatially-variable permeabilities. Taking into account the pumping test results, the geological background and the behaviour of injected CO2, we consider only the third configuration to be realistic. The results are in good agreement with modelled CO2 arrival times and pressure history.  相似文献   
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