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1.
作为一种节能技术,地表水源热泵广泛应用于供热和空调领域,但有研究指出,地表水源热泵的使用会对受纳水域造成水体热污染。简述了地表水源热泵温排水对水生生物的影响,在现有的水体热污染的评价方法上,提出了一种用水生生物评价地表水源热泵温排水的新方法,并以水生生物的Bray-Curtis不相似指数作为标准对水体热污染进行了分级。  相似文献   

2.
生物体内污染物的监测数据是评价环境质量的一个重要内容.近年来,环境生物监测有很大发展.特别是作为水生生物中较高营养级鱼类的鱼体中污染物分析,已有很多报道.长江是我国重要的淡水渔业基地之一.为了了解长江鱼类受污染的程度,我们  相似文献   

3.
从实际应用的角度研究景观水防腐技术,采用生物滤池、紫外线照射、投加次氯酸钠三种方法处理景观水,对景观水水质的TN、TP、COD、chla等指标进行检测,计算景观水的营养化指数,从而探索景观水防腐的最佳方法,为防止景观水富营养化提供科学依据.结果表明:经生物滤池处理的景观水可使TN、TP等营养物质下降到0.3 mg/L和...  相似文献   

4.
土壤中重金属的生物有效性分析方法及其影响因素综述   总被引:4,自引:0,他引:4  
土壤环境质量关系着粮食安全和生态安全。对土壤环境质量进行正确的评价尤为重要,而重金属的生物有效性对于揭示环境污染程度和评价生态风险具有重要意义,因此探寻土壤中重金属生物有效性的分析方法是目前国内外研究的热点。主要介绍了化学试剂提取法、薄膜扩散梯度技术(DGT)、道南膜技术(DMT)和同位素稀释法在重金属生物有效性分析方面的应用,并归纳了影响重金属生物有效性的主要因素,为重金属生物有效性分析方法的统一提供参考。  相似文献   

5.
轮虫作为水体污染的指示生物之一,其数量和种群组成可以用来评价水体的水质情况;但是,目前淮河流域水质评价仍以常规的理化指标评价为主,缺乏利用轮虫评价河流水质方面的研究。2012年12月和2013年7月,对淮河中上游10个生态监测点进行现场调查,获取轮虫种类、密度及水体理化指标等;利用生物多样性指数和综合营养状态指数分析水体污染和营养化状况,并利用Canoco软件分析轮虫群落结构与环境因子的关系。结果表明:研究期间共获得轮虫46种,其中污染指示种36种;各生态监测点具有不同的优势种群;总磷(TP)、化学需氧量(COD)和总氮(TN)是轮虫群落结构的共同环境影响因子;总体上水质从冬季到夏季有恶化的趋势,营养化程度有增加的趋势。研究工作可为淮河生态环境评估以及与富营养化密切相关的其他污染问题研究提供基础资料和依据。  相似文献   

6.
随着工农业生产的发展,汞、镉、铜、锌等重金属的需用量不断增加。与此同时,它们对渔业水域的危害也随之加重。重金属对鱼类及水生生物的影响主要取决于该元素的化学性质和生物的种类。一般说,水中重金属含量超过一定范围,不仅直接毒害水生生物,破坏水产资源,而且还通过食物链富集。因此,人们食用这类水生动物,有可能构成潜在的威胁。  相似文献   

7.
基于鄱阳湖湖区2008—2013年的水质监测数据,对鄱阳湖的水质现状及营养化水平进行评价,采用季节性Kendall检验法对鄱阳湖多年水质进行趋势分析。结果表明,2013年鄱阳湖湖区TP、TN普遍超过《地表水环境质量标准》(GB 3838—2002)中的Ⅲ类标准,富营养化状况在枯水期为轻度重营养化水平,丰水期为中度营养化水平。14个监测点位的氨氮浓度无明显变化,4个监测点位氨氮呈下降趋势;TP浓度总体呈下降趋势,说明水质状况有所好转,但湖区多数监测点位的TP年平均浓度超过GB 3838—2002中的Ⅲ类标准,未来仍需加强对鄱阳湖TP的控制。  相似文献   

8.
社会环境是人工创建的生态环境,它既包括物质环境,亦包括政治精神环境.社会环境既是物质文明和精神文明的标志,而又随着人类文明的演进而不断的丰富和发展. 对于一个地区,一个城市,进行全环境质量评价,仅仅做了大气、水、土壤、生物和噪声的评价是不够的,还应着重对以人类生态环境为中心的社会环境质量进行评价.  相似文献   

9.
前言 目前,我们在评价水体受重金属污染的现状,以及重金属对水生动植物的毒性作用或生物效应时,一般都是以金属的总浓度作指标,但这往往会获得令人误解的结果.重金属对水生动植物的毒性作用取决于其化学形态,例如铜对永生物的毒性是随其络合程度的增强而减弱的,铅和锌也有同样表现.通过研究重金属的化学形态,可以为水体质量评价提供有意义的数据并可较  相似文献   

10.
水体沉积物重金属生物有效性及评价方法   总被引:1,自引:0,他引:1  
在研究以重金属为主要污染物的水体中,通常把沉积物视为探索环境重金属污染的工具。由于沉积物中重金属化学行为和生态效应的复杂性,对沉积物中重金属生物有效性的研究是当前学术界的热点研究课题。本文就沉积物中重金属的生物有效性及沉积物质量评价方法作了简要评述。包括沉积物对水生生物的作用机理,孔隙水重金属浓度的估算,沉积物质量评价方法,沉积物质量基准。  相似文献   

11.
A number of key projects in the Environmental Protection Agency (EPA) particulate R&;D program having applicability to industry are presented. For electrostatic precipitators (ESP) there is presented the result of work on large diameter discharge electrodes which provide a decrease in penetration of up to a factor of 4 when compared to conventional small diameter electrodes. Also discussed is the multistage ESP which provides a collection efficiency that would require a collecting plate area 4 or 5 times larger with conventional ESP technology. The E-SOX technology makes use of the multistage concept to free up space in the ESP for SO2 removals of up to 90%. Electrostatically augmented fabric filtration provides a reduction in pressure drop of about 5 0% as compared to conventional fabric filtration. Wind tunnel modeling of windbreaks for material storage piles indicates a potential for providing engineering design data that would allow significant emission reduction caused by wind erosion  相似文献   

12.
This paper investigates some of the reflectivity characteristics that clouds (when modelled as solid bodies) must exhibit to be compatible with observations that the reflecting surface of a cloud (i) appears almost equally bright across its face, (ii) is brightest when the cloud is opposite to the Sun but decreases in brightness as the cloud moves to other positions and (iii) increases in brightness with increasing optical thickness of the cloud in the observer's line of sight. These observations, respectively, are shown to imply that the peak value of the bidirectional total reflectivity from a cloud surface (i) increases in inverse proportion to the cosine of the angle between the Sun and the normal to the cloud surface, as the incident angle increases, (ii) appears to be directed back in the direction of the incident radiation, and (iii) increases as optical thickness of the cloud in the observer's line of sight increases. The results could have application in many fields (e.g. modelling diffuse radiance distributions for cloudy skies).  相似文献   

13.
14.
介绍了电解法生产次氯酸钠的原理 ,并在原有生产工艺的基础上进行了重新设计和对设备的重新选择、改造 ,得出了各个工艺参数的最佳值 ,生产出高品质的次氯酸钠  相似文献   

15.
在实施ISO/IEC 17025:1999标准《检测和校准实验室能力的通用要求》过程中,通过实验室质量管理体系内部审核的实践与系统分析,识别出内部审核策划阶段的关键环节,提出审核范围确定、审核计划和抽样方案制订的质量控制要求,为有序高效地实施内部审核提供了技术方法。  相似文献   

16.
The most common technique used for numerical simulations of tracer mixing is that of the numerical solution of the advection–diffusion equation with the unresolved fluxes parameterized using the similarity theory. Despite correct predictions of the overall directions of transport, models based on a numerical solution of the advection–diffusion equation lack sufficient accuracy to correctly reproduce the coupling of mixing with small scale processes which are sensitive to the microstructure of the tracer distribution. The objective of this paper is to revisit the basic formalism employed in numerical models used to investigate atmospheric tracers. The main mathematical method proposed here is the theory of kinematics of mixing which could be applied effectively for simulations of atmospheric transport processes. At the beginning of the paper, we introduce simple mathematical transformations in order to demonstrate how complex topological structures are created by mixing processes. These idealistic flow systems are essential to explain transport properties of much more complex three-dimensional geophysical flows. An example of the application of the kinematics of mixing to the analysis of tracer transport on a planetary scale is presented in the following sections. The complex filamentary structures simulated in the numerical experiment are evaluated using some commonly applied statistical measures in order to compare the results with the data published in the literature. The results of the experiment are also analysed with the help of simple conceptual models of fluid filaments. The microstructure of the tracer distribution introduced in the paper is essential to increase our understanding of atmospheric transport and to develop more realistic parameterizations of small-scale mixing. The presented results could also be used to improve calculations of the coupling between microphysical processes and tracer mixing.  相似文献   

17.
Abstract

A computer model was used to take random samples from primary sample populations obtained from field trials to simulate the uncertainty of sampling for residue analysis of plant commodities and soil. The results indicate about 40%, 30% and 20% relative uncertainty when random samples of size 5, 10 and 25 are taken respectively, from a single lot. Therefore the sample size should be the same for establishing and enforcing legal limits.  相似文献   

18.
结合扬中生态环境的基本情况和存在的不足,进行了具体分析,对扬中未来生态建设的发展方向提出了建议及实施措施。  相似文献   

19.

Objective

This work aims to investigate the correlation between the photocatalytic activity determined by methylene blue bleaching (DIN 52980), stearic acid degradation, and degradation of acetone in gas phase.

Method

The photocatalytic TiO2 coatings included in this investigation ranged from thin commercially available coatings (ActivTM and BioCleanTM) and ready to use suspensions (Nano-X PK1245) to lab-produced PVD and sol?Cgel coatings. XRD analysis of the photocatalytic coatings showed that all the coatings consisted of nanocrystalline anatase, although the thickness and porosity varied considerably.

Results

The study showed that the reproducibility of the activity measurements was good. However, more importantly, the investigation showed that there is a good correlation between the activities determined by the different methods even though the characteristics of the photocatalytic coatings and the organic probe molecules varied considerably.

Conclusion

The overall findings of this work suggest that there is a good correlation between the investigated methods. These results are promising for the future work concerning standardization of methods for determination of the activity of photocatalytic films.  相似文献   

20.
Bhattacharya A  Sarkar SK 《Ambio》2003,32(1):70-75
India has a very extensive coastline of about 7515 km, rich in diverse living resources. These resources continue to deteriorate with rampant harvesting or are altered for other uses such as aquaculture and fisheries. The present paper deals with degrading coastal habitats in northeastern India, and projects the intensity of the stress arising from the collection of tiger prawn seeds (Penaeus monodon) for aquacultural farms and molluskan shells for poultry feed and edible lime. Indiscriminate exploitation of these resources leads to a heavy reduction of the species concerned and other associated marine communities. The magnitude of such destruction has been quantified. The impacts of biodiversity loss and their after-effects on the ecobalance of this coastal system have become a matter of great concern to ecologists to maintain security and sustainability. The authors propose a public awareness program on themes relating to the importance of biodiversity for human livelihoods.  相似文献   

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