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191.
以漂珠(FP)为载体,采用溶胶-凝胶-浸渍法制备了漂浮负载型CdS/TiO2/FP复合膜光催化剂,通过SEM、XRD对其结构进行了表征.以甘草膦农药的光催化降解为模型反应,使用不同光源研究了CdS/TiO2/FP的光催化性能,探讨了影响催化剂活性的因素及采用太阳光做光源处理草甘膦的可行性.结果表明,经4层镀膜500℃热处理的20%(w/w)CdS/TiO2/FP光催化剂具有良好的光催化性能,最佳降解条件为:催化剂加入量3 g/L,初始pH 7~9,Fe2 浓度为2.0×10-3 mol/L.通气量200 mL/min.在最佳条件下,对135 mg/L草甘膦溶液降解率可以分别达到96.3%(125 W高压汞灯,60 min)和82.4%(太阳光,180 min). 相似文献
192.
Comparison of China’s Environmental Impact Assessment (EIA) Law with the European Union (EU) EIA Directive 总被引:1,自引:0,他引:1
In this paper, we first review the development of China’s Environmental Impact Assessment (EIA) system in the past 30 years.
Then we compare the framework and operational procedures of China’s new EIA law with those of the EU EIA Directive. We also
compare public participation, as well as sanctions and control in the two EIA systems. In addition, we identify where the
processes in both EIA systems are similar or different from one another. By comparison, we noted that there are at least three
obvious weaknesses in China’s EIA system: (1) the application of new models for EIA legislation; (2) the improvement of EIA
guidance and education; and (3) the enhancement of public participation in EIA process. Our study indicates that these three
major shortcomings should be overcome and improved in China’s EIA system, when compared with the EU EIA system. 相似文献
193.
The present paper describes an effort for developing the total maximum daily load (TMDL) for phosphorus and a load reduction
strategy for the Feitsui Reservoir in Northern Taiwan. BASINS model was employed to estimate watershed pollutant loads from
nonpoint sources (NPS) in the Feitsui Reservoir watershed. The BASINS model was calibrated using field data collected during
a 2-year sampling period and then used to compute watershed pollutant loadings into the Feitsui Reservoir. The simulated results
indicate that the average annual total phosphorus (TP) loading into the reservoir is 18,910 kg/year, which consists of non-point
source loading of 16,003 kg/year, and point source loading of 2,907 kg/year. The Vollenweider mass balance model was used
next to determine the degree of eutrophication under current pollutant loading and the load reduction needed to keep the reservoir
from being eutrophic. It was estimated that Feitsui Reservoir can becoming of the oligotrophic state if the average annual
TP loading is reduced by 37% or more. The results provide the basis on which an integrated control action plan for both point
and nonpoint sources of pollution in the watershed can be developed. 相似文献
194.
Isobe T Takada H Kanai M Tsutsumi S Isobe KO Boonyatumanond R Zakaria MP 《Environmental monitoring and assessment》2007,135(1-3):423-440
A comprehensive monitoring survey for polycyclic aromatic hydrocarbons (PAHs) and phenolic endocrine disrupting chemicals
(EDCs) utilizing mussels as sentinel organisms was conducted in South and Southeast Asia as a part of the Asian Mussel Watch
project. Green mussel (Perna viridis) samples collected from a total of 48 locations in India, Indonesia, Singapore, Malaysia, Thailand, Cambodia, Vietnam, and
the Philippines during 1994–1999 were analyzed for PAHs, EDCs including nonylphenol (NP), octylphenol (OP) and bisphenol A
(BPA), and linear alkylbenzenes (LABs) as molecular markers for sewage. Concentrations of NP ranged from 18 to 643 ng/g-dry
tissue. The highest levels of NP in Malaysia, Singapore, the Philippines, and Indonesia were comparable to those observed
in Tokyo Bay. Elevated concentrations of EDCs were not observed in Vietnam and Cambodia, probably due to the lower extent
of industrialization in these regions. No consistent relationship between concentrations of phenolic EDCs and LABs were found,
suggesting that sewage is not a major source of EDCs. Concentrations of PAHs ranged from 11 to 1,133 ng/g-dry, which were
categorized as “low to moderate” levels of pollution. The ratio of methylphenanthrenes to phenanthrene (MP/P ratio) was >1.0
in 20 out of 25 locations, indicating extensive input of petrogenic PAHs. This study provides a bench-mark for data on the
distribution of anthropogenic contaminants in this region, which is essential in evaluating temporal and spatial variation
and effect of future regulatory measures. 相似文献
195.
Spectroscopic Distribution of Dissolved Organic Matter in a Dam Reservoir Impacted by Turbid Storm Runoff 总被引:1,自引:0,他引:1
Spectroscopic characteristics of dissolved organic matter (DOM) in a large dam reservoir were determined using ultraviolet
absorbance and fluorescence spectroscopy to investigate spatial distribution of DOM composition after turbid storm runoff.
Water samples were collected along a longitudinal axis of the reservoir at three to four depths after a severe storm runoff.
Vertical profiles of turbidity data showed that a turbid water layer was located at a middle depth of the entire reservoir.
The spectroscopic characteristics of DOM samples in the turbid water layer were similar to those of terrestrial DOM, as demonstrated
by the higher specific UV absorbance (SUVA) and the lower fluorescence emission intensity ratio (F
450/F
500) compared to other surrounding DOM samples in the reservoir. Synchronous fluorescence spectroscopy revealed that higher content
of humic-like DOM composition was contained in the turbid water. Fluorescence excitation–emission matrix (EEM) showed that
lower content of protein-like aromatic amino acids was present in the turbid water DOM. The highest protein-like fluorescence
was typically observed at a bottom layer of each sampling location. The bottom water DOM exhibited extremely high protein-like
florescence near the dam site. The particular observation was attributed to the low water temperature and the isolation of
the local bottom water due to the upper location of the withdrawal outlet near the dam. Our results suggest that the distribution
of DOM composition in a dam reservoir is strongly influenced by the outflow operation, such as selective withdrawal, as well
as terrestrial-origin DOM inputs from storm runoff. 相似文献
196.
NOx分解还原催化研究进展 总被引:1,自引:0,他引:1
介绍和评价了NO_x分解还原的3类催化剂:贵金属催化剂、氧化物催化剂、金属离子置换的分子筛。在NO_x的碳氢化合物选择性催化还原反应(HC-SCR反应)中,同样有3类催化剂,即金属氧化物、贵金属和分子筛。由于Cu-ZSM-5是目前最有希望投入实际使用的一种,故本文重点介绍了它对NO_x的HC-SCR反应的催化机理,以及温度、O_2含量、Cu~(2+)的置换度、不同种类HC及HC含量等各种因素对Cu-ZSM-5的影响,并对其工作台试验进行了评价,指出了其存在的问题及当前的研究热点。 相似文献
197.
198.
单甲脒饱和蒸气压的测定和估算 总被引:1,自引:0,他引:1
用气体的法测单甲脒在15,25,35和45℃时的饱和蒸气分别为0.202,0.5546,1.95,6.29Pa;亨利常数计算值分别为6.30×10^-4,1.67×10^-3,5.68×10^0-3和1.78×10&-2,根据Clausius Clapeyron方程求出单甲脒在常温下气化热为89.2kJ.mol^-1。 相似文献
199.
200.
Park JS Oh S Shin MY Kim MK Yi SM Zoh KD 《Environmental pollution (Barking, Essex : 1987)》2008,154(1):12-20
Dissolved gaseous mercury (DGM) and total mercury (TM) concentrations were measured in Juam Reservoir, Korea. DGM concentrations were higher in spring (64+/-13pgL(-1)) and summer (109+/-15pgL(-1)), and lower in fall (20+/-2pgL(-1)) and winter (23+/-6pgL(-1)). In contrast, TM concentrations were higher in fall (3.2+/-0.1ngL(-1)) and winter (3.3+/-0.1ngL(-1)) than in spring (2.3+/-0.1ngL(-1)) and summer (2.2+/-0.4ngL(-1)). DGM concentrations were correlated with water temperature (p<0.0001), ORP (p<0.0001), UV intensity (UV-A: p=0.008; UV-B: p=0.003), and DOC concentration (p=0.0107). DGM concentrations varied diurnally with UV intensity. The average summer DGM (109+/-15pgL(-1)) and TM (2.2+/-0.4ngL(-1)) concentrations in Juam Reservoir were higher than the averages for North American lakes (DGM=38+/-16pgL(-1); TM=1.0+/-1.2ngL(-1)), but lower than levels reported for Baihua Reservoir in China. 相似文献