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131.
This study aims to investigate the treatment of paper mill effluents using electrocoagulation. Removal of lignin, phenol, chemical oxygen demand (COD) and biological oxygen demand (BOD) from paper mill effluents was investigated at various current intensities by using different electrodes (Al and Fe) and at various electrolysis times (1.0, 2.5, 5.0 and 7.5min). It was observed that the experiments carried out at 12V, an electrolysis time of 2min and a current intensity of 77.13mA were sufficient for the removal of these pollutants with each electrode. The removal capacities of the process using an Al electrode were 80% of lignin, 98% of phenol, 70% of BOD, and 75% of COD after 7.5min. Using an Fe electrode the removal capacities were 92%, 93%, 80% and 55%, respectively. In addition, it was found that removal of lignin, phenol, BOD and COD increased with increasing current intensity. In the experiments carried out at different current intensities, higher removal can be explained through a decrease in intra-resistance of solution and consequently an increase at the transfer speed of organic species to electrodes. It was also found that Al electrode performs higher efficiency than Fe electrode except for COD removal. However, the time required for removal of BOD was more than that of COD. The results suggest that electrocoagulation could be considered as an effective alternative to paper mill effluents treatment. 相似文献
132.
Kraigher H Al Sayegh Petkovsek S Grebenc T Simoncic P 《Environmental monitoring and assessment》2007,128(1-3):31-45
Mycorrhiza is the main spatial and temporal linkage between different constituents in a forest ecosystem. The functional compatibility
and stress tolerance of ectomycorrhizal types is species specific, and therefore the information on the ectomycorrhizal community
structure can add to the understanding of processes in forest ecosystems and can also be applied as tools for bioindication
of pollution stress in forest soils. We have studied the effects of pollution (N and S) on trees and forest soils by: (1)
quantification of ECM types diversity as in situ indicators in forest stands, (2) determination and quantification of pollution-sensitive or -insensitive ECM types as passive
monitors, (3) root growth and development of ECM on nonmycorrhizal spruce seedlings, planted at the studied sites (active
monitors), and (4) ECM infection (a bioassay based on mycorrhizal inoculum potential) of seedlings in an experimental set-up
as ex situ testers. ECM species richness for Norway spruce trees (Picea abies) showed higher values in unpolluted sites than in polluted ones, while the differences were not significant for European
beech trees (Fagus sylvatica). As pollution-sensitive or -insensitive ECM species in spruce forests, we suggest Hydnum rufescens (sensitive) and Paxillus involutus (unsensitive). Mycorrhizal potential in Norway spruce seedlings as a bioassay for soil N and S pollution was effective, and
is suggested as an additional, standardized and widely comparable system in bioindication of soil pollution. 相似文献
133.
北京春季城区与远郊区不同大气粒径颗粒物中水溶性离子的分布特征 总被引:2,自引:0,他引:2
为比较北京城区与远郊区大气颗粒物中水溶性无机离子的组成特征,2012年4月,利用Andersen分级撞击式采样器同时在2个采样点进行大气颗粒物分级采样,样品采用离子色谱分析.结果表明,城区和上甸子大气颗粒物中水溶性无机离子总浓度分别为(83.7±48.9)μg·m-3和(75.5±52.9)μg·m-3,NO-3、SO2-4和NH+4是最主要的水溶性无机离子,分别占总离子浓度的81.2%和84.2%.粒径分布显示,Mg2+和Ca2+在5.8~9.0μm的粒径范围出现峰值,Na+、NH+4、Cl-在0.43~1.1μm和4.7~9.0μm的粒径范围出现双峰,K+、NO-3和SO2-4在0.65~2.1μm的粒径范围出现峰值.后向轨迹簇分析表明,气团来自南方时,城区和上甸子二次离子浓度分别为(92.4±40.0)μg·m-3和(95.0±35.4)μg·m-3,来自其他方向时,分别为(24.0±10.8)μg·m-3和(13.3±10.6)μg·m-3. 相似文献
134.
135.
Ranko Glumac Ramona Franić Andrej Udovč 《Journal of Environmental Planning and Management》2017,60(1):67-91
The agri-environmental programme (AEP) is the European Union policy instrument used for the delivery of environmental services expected by the society, but societal expectations for these environmental services are insufficiently assessed. In order to realistically meet the expectations of AEP, this research utilises analytical hierarchy process based web survey to assess the importance that various societal stakeholders in the European countries of Slovenia and Croatia give to specific environmental services and to also identify the agricultural practices that have the greatest potential to realise the expectations that society values the most. All stakeholders (overall group) from Slovenia and Croatia ranked water quality and availability as the first most important environmental service, and reduction of pesticides as the most important agricultural practice to deliver societal expectations. The results indicate that there is similar demand for environmental services in these two countries that differ in their agricultural settings. 相似文献
136.
加速我国环保产业的发展 总被引:4,自引:0,他引:4
简述了环保产业是未来世纪产业,介绍了国内外环保产业的现状及我国环保产业存在的问题,对发展我国环保产业提出了对策和建议。 相似文献
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140.
Kinetic analyses were made of the stable sodium and radioactive sodium (22Na) in some tissues of the crab Carcinus mediterraneus CSRN. Fast 22Na outflux constant is increased in gills, hepatopancreas, hemolymph, digestive tract and muscles. In the reproductive organs the values of the sodium outflux constant are lower. The values of the fast outflux rates (t=20°C) of sodium amount, in the whole animal, to 22.5 M Na/g/h, in the hemolymph, to 69.3 M Na/g/h; the slow outflux rates have much lower values (0.02 to 0.13 M Na/g/h). Moulting crabs show a rate of sodium outflux 6 times greater than that of intermoulting individuals. 相似文献