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131.
132.
Legitimizing Fluvial Ecosystems as Users of Water: An Overview 总被引:6,自引:0,他引:6
Naiman RJ Bunn SE Nilsson C Petts GE Pinay G Thompson LC 《Environmental management》2002,30(4):455-467
We suggest that fluvial ecosystems are legitimate users of water and that there are basic ecological principles guiding the
maintenance of long-term ecological vitality. This article articulates some fundamental relationships between physical and
ecological processes, presents basic principles for maintaining the vitality of fluvial ecosystems, identifies several major
scientific challenges and opportunities for effective implementation of the basic ecological principles, and acts as an introduction
to three specific articles to follow on biodiversity, biogeochemistry, and riparian communities. All the objectives, by necessity,
link climate, land, and fresh water. The basic principles proposed are: (1) the natural flow regime shapes the evolution of
aquatic biota and ecological processes, (2) every river has a characteristic flow regime and an associated biotic community,
and (3) aquatic ecosystems are topographically unique in occupying the lowest position in the landscape, thereby integrating
catchment-scale processes. Scientific challenges for the immediate future relate to quantifying cumulative effects, linking
multidisciplinary knowledge and models, and formulating effective monitoring and assessment procedures. Additionally, forecasting
the ecological consequences of changing water regimes is a fundamental challenge for science, especially as environmental
issues related to fresh waters escalate in the next two to three decades. 相似文献
133.
134.
氨法脱硫副产物亚硫酸铵的塔外氧化 总被引:2,自引:0,他引:2
根据氨法脱硫反应机理,提出了将脱硫生成的亚硫酸铵溶液排放到吸收塔外进行氧化的方法,一方面可以减少脱硫塔的注氨量,有效控制吸收塔出口烟气中的逸氨及硫酸铵气溶胶,避免二次污染;另一方面,可以提高吸收塔内亚硫酸铵浓度,保持较高的脱硫率.塔外氧化对于氨法脱硫是一种比较合理的氧化方法. 相似文献
135.
UPLC-MS/MS法同时测定地表水中多种有机污染物 总被引:1,自引:0,他引:1
采用超高效液相色谱-串联质谱法直接进样测定地表水中26种有机污染物,通过优化试验条件,使各目标化合物在1.00μg/L^100μg/L范围内线性良好,相关系数(r 2)>0.995,方法检出限为0.003μg/L^1.0μg/L。将该方法用于地表水样的测定,加标回收率为79.0%~120%,6次测定结果的RSD均<15%。 相似文献
136.
随着近30年来中原油田高强度、大面积的石油开采,高强度注水采油和超采地下水造成的负面效应日益凸现。通过地下水位下降,地下漏斗面积增大,地面沉降,地裂缝,土壤、水体污染五个方面阐述了注水采油带来的生态环境问题,以及由此导致的对公共设施和建筑物的破坏、水土污染等严重后果。 相似文献
137.
138.
Xuebiao Nie Wenjun Liu Mo Chen Minmin Liu Lu Ao 《Frontiers of Environmental Science & Engineering》2016,10(6):12
Flow cytometry (FCM) has been widely used in multi-parametric assessment of cells in various research fields, especially in environmental sciences. This study detected the metabolic activity of Escherichia coli and Staphylococcus aureus by using an FCM method based on 5-cyano-2,3-ditolyltetrazolium chloride (CTC); the accuracy of this method was enhanced by adding SYTO 9 and 10%R2A broth. The disinfection effects of chlorine, chloramine, and UV were subsequently evaluated by FCM methods. Chlorine demonstrated stronger and faster destructive effects on cytomembrane than chloramine, and nucleic acids decomposed afterwards. The metabolic activity of the bacteria persisted after the cytomembranewas damaged as detected using CTC. Low-pressure (LP) UV or medium-pressure (MP) UV treatments exerted no significant effects on membrane permeability. The metabolic activity of the bacteria decreased with increasing UV dosage, and MP-UV was a stronger inhibitor of metabolic activity than LP-UV. Furthermore, the membrane of Gram-positive S. aureus was more resistant to chlorine/chloramine than that of Gram-negative E. coli. In addition, S. aureus showed higher resistance to UV irradiation than E. coli. 相似文献
139.
Understanding effects of flow alteration on stream biota is essential to developing ecologically sustainable water supply
strategies. We evaluated effects of altering flows via surface water withdrawals and instream reservoirs on stream fish assemblages,
and compared effects with other hypothesized drivers of species richness and assemblage composition. We sampled fishes during
three years in 28 streams used for municipal water supply in the Piedmont region of Georgia, U.S.A. Study sites had permitted
average withdrawal rates that ranged from < 0.05 to > 13 times the stream’s seven-day, ten-year recurrence low flow (7Q10),
and were located directly downstream either from a water supply reservoir or from a withdrawal taken from an unimpounded stream.
Ordination analysis of catch data showed a shift in assemblage composition at reservoir sites corresponding to dominance by
habitat generalist species. Richness of fluvial specialists averaged about 3 fewer species downstream from reservoirs, and
also declined as permitted withdrawal rate increased above about 0.5 to one 7Q10-equivalent of water. Reservoir presence and
withdrawal rate, along with drainage area, accounted for 70% of the among-site variance in fluvial specialist richness and
were better predictor variables than percent of the catchment in urban land use or average streambed sediment size. Increasing
withdrawal rate also increased the odds that a site’s Index of Biotic Integrity score fell below a regulatory threshold indicating
biological impairment. Estimates of reservoir and withdrawal effects on stream biota could be used in predictive landscape
models to support adaptive water supply planning intended to meet societal needs while conserving biological resources. 相似文献
140.
Coal combustion and mercury pollution are closely linked, and this relationship is particularly relevant in China, the world's largest coal consumer. This paper begins with a summary of recent China-specific studies on mercury removal by air pollution control technologies and then provides an economic analysis of mercury abatement from these emission control technologies at coal-fired power plants in China. This includes a cost-effectiveness analysis at the enterprise and sector level in China using 2010 as a baseline and projecting out to 2020 and 2030. Of the control technologies evaluated, the most cost-effective is a fabric filter installed upstream of the wet flue gas desulfurization system (FF + WFGD). Halogen injection (HI) is also a cost-effective mercury-specific control strategy, although it has not yet reached commercial maturity. The sector-level analysis shows that 193 tons of mercury was removed in 2010 in China's coal-fired power sector, with annualized mercury emission control costs of 2.7 billion Chinese Yuan. Under a projected 2030 Emission Control (EC) scenario with stringent mercury limits compared to Business As Usual (BAU) scenario, the increase of selective catalytic reduction systems (SCR) and the use of HI could contribute to 39 tons of mercury removal at a cost of 3.8 billion CNY. The economic analysis presented in this paper offers insights on air pollution control technologies and practices for enhancing atmospheric mercury control that can aid decision-making in policy design and private-sector investments. 相似文献