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22.
河流水环境质量评价研究——对评价系统、评价方法的新探讨 总被引:1,自引:0,他引:1
本文旨在对河流水环境资源中水质、水量二要素的评价以及对定量、定性数据的综合评价进行方法论上的探讨。文中提出了模糊数学评价的改进方法,建立了一套水量评价标准和评价方法;建立了“优势度”概念并提出了水质、水量多目标定量、定性数据综合评价方法。以四川省沱江为例,对上述方法进行验证,根据评价结果划分河段,并对各河段的水资源合理利用及水环境规划提出建议。 相似文献
23.
24.
涤沦仿真丝印染废水治理技术的研究及其应用 总被引:8,自引:0,他引:8
采用化学法去除对苯二甲酸,对高浓度涤纶仿真丝印染废水进行治理。结果表明:该技术对碱减量废水中CODCr的去除有显著的效果。当废水的pH值在12~14,CODCr含量在10000~33000mg/L时,将废水的pH值调节到4~6,出水CODCr能降至1000~2700mg/L之间,CODCr去除率为77%~955%。为涤纶纺真丝印染废水治理达标排放奠定了基础 相似文献
25.
ABSTRACTThe present study was carried out to investigate the effect of three organic matters (stalk powder, microbial fertilizer, and manure) on Leymus chinensis germination, growth, and urease activity and available nitrogen (N) in coastal saline soil. The study was conducted in a completely randomized design with eight treatments: J0V0Y0, J1V0Y0, J0V1Y0, J0V0Y1, J1V1Y0, J1V0Y1, J0V1Y1, J1V1Y1. The notations were based on the quantities of each agent added to 1 kg of coastal saline soil: J0 – no straw powder, J1 – 0.2 kg straw powder, Y0 – no manure, Y1 – 0.3 kg manure, V0 – no microbial fertilizer, V1 – 0.2 L microbial fertilizer, each in quantic repeat. L. chinensis was sown as 50 seeds per pot. Results indicated that addition of organic agents exerted a significantly enhanced germination, increase in fresh weight and elevated soil urease activity. Soil available N levels were significantly positively correlated with soil urease activity and fresh weight, but not with germination rate. It is noteworthy that the halophyte L. chinensis showed improved characteristics when grown in coastal saline soil with addition of organic amendments. 相似文献
26.
Benjamin P. Louis Pierre-Alain Maron Valérie Viaud Philippe Leterme Safya Menasseri-Aubry 《Environmental Chemistry Letters》2016,14(3):331-344
Industrial agriculture is yearly responsible for the loss of 55–100 Pg of historical soil carbon and 9.9 Tg of reactive nitrogen worldwide. Therefore, management practices should be adapted to preserve ecological processes and reduce inputs and environmental impacts. In particular, the management of soil organic matter (SOM) is a key factor influencing C and N cycles. Soil microorganisms play a central role in SOM dynamics. For instance, microbial diversity may explain up to 77 % of carbon mineralisation activities. However, soil microbial diversity is actually rarely taken into account in models of C and N dynamics. Here, we review the influence of microbial diversity on C and N dynamics, and the integration of microbial diversity in soil C and N models. We found that a gain of microbial richness and evenness enhances soil C and N dynamics on the average, though the improvement of C and N dynamics depends on the composition of microbial community. We reviewed 50 models integrating soil microbial diversity. More than 90 % of models integrate microbial diversity with discrete compartments representing conceptual functional groups (64 %) or identified taxonomic groups interacting in a food web (28 %). Half of the models have not been tested against an empirical dataset while the other half mainly consider fixed parameters. This is due to the difficulty to link taxonomic and functional diversity. 相似文献
27.
Guanglong Pang Donghui Wang Yunhong Zhang Chunyan Ma Zhengping Hao 《Frontiers of Environmental Science & Engineering》2016,10(3):447-457
MnO2 microspheres with various surface structures were prepared using the hydrothermal method, and Au/MnO2 catalysts were synthesized using the sol-gel method. We obtained three MnO2 microspheres and Au/MnO2 samples: coherent solid spheres covered with wire-like nanostructures, solid spheres with nanosheets, and hierarchical hollow microspheres with nanoplatelets and nanorods. We investigated the properties and catalytic activities of formaldehyde oxidation at room temperature. Crystalline structures of MnO2 are the main factor affecting the catalytic activities of these samples, and γ-MnO2 shows high catalytic performance. The excellent redox properties are responsible for the catalytic ability of γ-MnO2. The gold-supported interaction can change the redox properties of catalysts and accelerate surface oxygen species transition, which can account for the catalytic activity enhancement of Au/MnO2. We also studied intermediate species. The dioxymethylene (DOM) and formate species formed on the catalyst surface were considered intermediates, and were ultimately transformed into hydrocarbonate and carbonate and then decomposed into CO2. A proposed mechanism of formaldehyde oxidation over Au/MnO2 catalysts was also obtained. 相似文献
28.
Reimo Rivis Are Kont Urve Ratas Valdeko Palginõmm Kait Antso Hannes Tõnisson 《Journal of Coastal Conservation》2016,20(3):199-209
The structure of coastal land cover in Estonia is intricate and exhibits considerable differences from site to site. The diverse geomorphology of the seashores is one of the key factors affecting the speed and magnitude of land cover changes. Likewise, the history of human inhabitance on the coast has also shaped the character of land cover. The Estonian coastal zone has experienced abrupt and radical changes in land ownership and its related land use during the last century. The main objectives of this paper are: 1) to give an overview of land use and the trends of development of land cover pattern along different parts of the Estonian coast; and 2) to analyze the relationships of natural and human processes and their cumulative impact on the evolution of coastal land cover pattern in Estonia. This study is based on results obtained during fieldwork in the study areas and on the analysis of large-scale (1:10,000) historical maps. In agriculturally dominant coastal areas, the traditional open landscape of fields and grassland at the beginning of the 20th century had been replaced by woodland and grasslands with shrubs by the start of the 21st century. Expansion of reed beds in areas of former seashore grasslands is another striking phenomenon. The structure of land cover on forested coasts has been fairly stable during the last 100 years. Areas of urban sprawl are characterised by dramatic changes in land cover structure. Rapidly increasing population and expanding settlements imposes on the ecological balance of the fragile dune forests in the coastal zone. 相似文献
29.
Alamgir Hossain Jamal Naser Monzur Alam Imteaz 《Environmental Modeling and Assessment》2011,16(4):359-367
This paper presents comprehensive 3D numerical investigations on depositions of particles flowing through a horizontal pipe
loop consisting of four bends. The multiphase mixture model available in FLUENT 6.2 was used in this study. In this numerical
simulation, five different particle sizes have been used as secondary phases to calculate real multiphase effect in which
inter-particle interaction has been considered. The deposition of particles along the periphery of the pipe wall was investigated
as a function of particle size and fluid velocity. The simulations showed that near the upstream of the bends, maximum particle
concentration occurred at the bottom of the pipe. However, downstream the bends, the maximum particle concentration occurred
at an angle of 60° from the bottom. The larger particles clearly showed deposition near the bottom wall except downstream.
As expected, the smaller particles showed less tendency of deposition and lesser at higher velocity. This numerical investigation
showed qualitative agreement with the experiments conducted by Commonwealth Scientific and Industrial Research Organisation,
Melbourne team for similar conditions. 相似文献
30.
Konstantinos C. Makris Dibyendu Sarkar Jason Salazar Pravin Punamiya Rupali Datta 《Environmental science and pollution research international》2010,17(1):195-202