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用大型底栖动物和ODP系统评价珠江的有机污染 总被引:1,自引:2,他引:1
采用大型底栖动物需氧有机体百分率ODP(oxygen demander percentage)法对广州珠江前航道、西航道和流溪河的下游段进行河流有机污染评价.结果显示:底栖动物需氧类群密度在三河段间分布确有显著性差异,并根据其ODP可以判断流溪河水质相对较好,水质级别为中国地表水环境质量标准(EQSSW)Ⅳ级,西航道和前航道水质级别都为Ⅴ级.通过测试,这一方法能成功地应用在珠江及流溪河,且该法可以较好地匹配于EQSSW五级评价系统,初步认为ODP系统可以成为一个较好的河流水质生物监测方法.图3表4参13 相似文献
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SOON-WOONG CHANG SI-JIN LEE CHUNG-HWAN JE 《Journal of environmental science and health. Part. B》2013,48(6):801-811
Toxicity, uptake, and transformation of atrazine [2-chloro-4-(ethylamino)-6-(isopropylamino)-s-triazine] by three species of poplar tree were assessed. Poplar cuttings were grown in sealed flasks with hydrophonic solutions and exposed to various concentrations of atrazine for a period of two weeks. Toxicity effects were evaluated by monitoring transpiration and measuring poplar cutting mass. Exposure to higher atrazine concentrations resulted in decrease of biomass and transpiration accompanied by leaf chlorosis and abscission. However, poplar cuttings exposed to lower concentrations of atrazine grew well and transpired at a constant rate during experiment periods. Poplar cuttings could take up, hydrolyze, and dealkylate atrazine to less toxic metabolites. Metabolism of atrazine occurred in roots, stems, and leaves and became more complete with increased residence time in tissue. These results suggest that phytoremediation is a viable approach to removing atrazine from contaminated water and should be considered for other contaminants. 相似文献
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Venkata Srinivas Challa Jayakumar Indrcanti Julius M. Baham Chuck Patrick Monika K. Rabarison John H. Young Robert Hughes Shelton J. Swanier Mark G. Hardy Anjaneyulu Yerramilli 《Environmental Fluid Mechanics》2008,8(4):367-387
Mesoscale transport and dispersion of air pollutants from a few major point sources in the Mississippi Gulf coastal region
is calculated using a coupled modeling system consisting of the atmospheric dynamical model WRF and the lagrangian particle
model HYSPLIT. The sensitivity of the dispersion model results to the meteorological fields is studied by conducting an ensemble
of simulations using the WRF model for the same dispersion case. Several parameterization schemes for the physical processes
of boundary layer turbulence and land surface temperature/moisture prediction in WRF are used in various combinations to produce
different meteorological members which are then used for dispersion simulation. The uncertainty in the simulated concentration
probabilities to the meteorological model configurations and the ensemble mean are presented. The parameters used for determining
the uncertainties include the wind fields, temperature, area of concentration and the levels of concentration. The results
indicate that dispersion model results are influenced by the choices made in respect of the planetary boundary layer and land
surface schemes in the mesoscale model to produce the meteorological forecast thereby leading to certain amount of uncertainty
in the resultant concentrations. Results show that the specific choices made about the atmospheric model configuration can
significantly after the simulated concentrations. 相似文献
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Nitrate removal effectiveness of a riparian buffer along a small agricultural stream in western Oregon 总被引:3,自引:0,他引:3
Wigington PJ Griffith SM Field JA Baham JE Horwath WR Owen J Davis JH Rain SC Steiner JJ 《Journal of environmental quality》2003,32(1):162-170
The Willamette Valley of Oregon has extensive areas of poorly drained, commercial grass seed lands. Little is know about the ability of riparian areas in these settings to reduce nitrate in water draining from grass seed fields. We established two study sites with similar soils and hydrology but contrasting riparian vegetation along an intermittent stream that drains perennial ryegrass (Lolium perenne L.) fields in the Willamette Valley of western Oregon. We installed a series of nested piezometers along three transects at each site to examine NO3-N in shallow ground water in grass seed fields and riparian areas. Results showed that a noncultivated riparian zone comprised of grasses and herbaceous vegetation significantly reduced NO3-N concentrations of shallow ground water moving from grass seed fields. Darcy's law-based estimates of shallow ground water flow through riparian zone A/E horizons revealed that this water flowpath could account for only a very small percentage of the streamflow. Even though there is great potential for NO3-N to be reduced as water moves through the noncultivated riparian zone with grass-herbaceous vegetation, the potential was not fully realized because only a small proportion of the stream flow interacts with riparian zone soils. Consequently, effective NO3-N water quality management in poorly drained landscapes similar to the study watershed is primarily dependent on implementation of sound agricultural practices within grass seed fields and is less influenced by riparian zone vegetation. Wise fertilizer application rates and timing are key management tools to reduce export of NO3-N in stream waters. 相似文献
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