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521.
黄孢原毛平革菌(Phanerochaete chrysosporium)对3种酚酸物质的降解作用 总被引:1,自引:0,他引:1
研究黄孢原毛平革菌(P.chrysosporium)对香草酸、阿魏酸、对羟基苯甲酸的降解作用.结果表明,300 μg/mL的上述3种酚酸物质与黄孢原毛平革菌共培养2 d后,3种酚酸物质的降解率分别达到73.48%、99.09%和54.74%.黄孢原毛平革菌发酵上清液对3种酚酸物质的降解能力较弱,作用2 d后,降解率分别为13.28%,4.47%和5.43%,而该菌菌丝体降解能力很强,作用2 d后3种酚酸物质的降解率分别达到65%,98.37%和48.69%.研究表明,黄孢原毛平革菌对这3种酚酸的降解主要在菌体表面或体内进行. 相似文献
522.
二氯异氰脲酸钠和三氯异氰脲酸对棕囊藻细胞去除的研究 总被引:2,自引:2,他引:0
研究了二氯异氰脲酸钠和三氯异氰脲酸对球形棕囊藻的灭杀和控制作用,及其投药时间对除藻效果的影响,并比较2种药剂的除藻效果,初步探讨了除藻机理.结果表明,这2种除藻剂可以缓释次氯酸,提高其稳定性,有较长的药效期.当有效氯浓度达到4.5mg/L时,2种药剂均能有效地控制和灭杀球形棕囊藻,具有高效、低毒的优点.有效氯浓度为5.0mg/L,藻细胞去除率在24h可达到90%以上.在等于和大于5.0mg/L有效氯浓度时,三氯异氰脲酸的除藻效果优于二氯异氰脲酸钠,通过对2种药剂除藻率的t检验进一步证实了这一结论. 相似文献
523.
Perfluorinated Surfactants in Surface and Drinking Waters (9 pp) 总被引:1,自引:0,他引:1
Skutlarek D Exner M Färber H 《Environmental science and pollution research international》2006,13(5):299-307
Background, Aim and Scope
In this paper recent results are provided of an investigation on the discovery of 12 perfluorinated surfactants (PS) in different
surface and drinking waters (Skutlarek et al. 2006 a, Skutlarek et al. 2006 b). In the last years, many studies have reported
ubiquitous distribution of this group of perfluorinated chemicals, especially perfluorooctane sulfonate (PFOS) and perfluorooctanoic
acid (PFOA) in the environment, particularly in wildlife animal and human samples (Giesy and Kannan 2001, Houde et al. 2006,
Prevedouros et al. 2006). Perfluorinated surfactants (e.g. PFOS and PFOA) have shown different potentials for reproductory
interference and carcinogenity in animal experiments as well as partly long half-lives in humans (Guruge et al. 2006, FSA
UK 2006a, FSA UK 2006b, 3M 2005, OECD 2002, Yao and Zhong 2005). They possess compound-dependent extreme recalcitrance against
microbiological and chemical degradation and, in addition, they show variable potentials for bioaccumulation in animals and
humans (Houde et al. 2006).
Materials and Methods:
Surface and drinking water samples were collected from different sampling sites:
- Surface waters: samples taken from the rivers Rhine, Ruhr, Moehne and some of their tributaries. Further samples were taken
from the Rhine-Herne-Canal and the Wesel-Datteln-Canal.
- Drinking waters: samples taken in public buildings of the Rhine-Ruhr area.
After sample clean-up and concentration by solid-phase extraction, the perfluorinated surfactants were determined using HPLC-MS/MS.
Results:
All measured concentrations (sum of seven mainly detected components) in the Rhine river and its main tributaries (mouths)
were determined below 100 ng/L. The Ruhr river (tributary of the Rhine) showed the highest concentration (94 ng/L), but with
a completely different pattern of components (PFOA as major component), as compared with the other tributaries and the Rhine
river. Further investigations along the Ruhr river showed remarkably high concentrations of PS in the upper reaches of the
Ruhr river and the Moehne river (tributary of the Ruhr) (Ruhr: up to 446 ng/L, Moehne: up to 4385 ng/L). The maximum concentration
of all drinking water samples taken in the Rhine-Ruhr area was determined at 598 ng/L with the major component PFOA (519 ng/L).
Discussion:
The surface water contaminations most likely stem from contaminated inorganic and organic waste materials (so-called 'Abfallgemisch').
This waste material was legally applied to several agricultural areas on the upper reaches of the Moehne. Perfluorinated surfactants
could be detected in some suchlike soil samples. They contaminated the river and the reservoir belonging to it, likely by
superficial run-off over several months or probably years. Downstream, dilution effects are held responsible for decreasing
concentrations of PS in surface waters of the Moehne and the Ruhr river. In analogy to the surface water samples, PS (major
component PFOA) can be determined in many drinking water samples of the Rhine-Ruhr area where the water supplies are mainly
based on bank filtration and artificial recharge.
Conclusions:
The concentrations found in drinking waters decreased with the concentrations of the corresponding raw water samples along
the flow direction of the Ruhr river (from east to west) and were not significantly different from surface water concentrations.
This indicates that perfluorinated surfactants are at present not successfully removed by water treatment steps.
Recommendations and Perspectives:
Because of their different problematic properties (persistence, mobility, toxicity, bioaccumulation), the concentrations of
specific perfluorinated surfactants and their precursors in drinking waters and food have to be minimised. Therefore, it is
of utmost importance to take the initiative to establish suitable legal regulations (limitations/ban) concerning the production
and use of these surfactants and their precursors. Furthermore, it is indispensable to protect water resources from these
compounds. A discussion on appropriate limit values in drinking water and foodstuffs is urgently needed. Concerning the assumed
soil contamination, the corresponding regulation (Bioabfall-Verordnung 1998 – Regulation on Organic Waste 1998) should be
extended to allow the control of relevant organic pollutants. 相似文献
524.
Totsche O Fyson A Kalin M Steinberg CE 《Environmental science and pollution research international》2006,13(4):215-224
Background, Aims and Scope The acidification of mine waters is generally caused by metal sulfide oxidation, related to mining activities. These waters
are characterized by low pH and high acidity due to strong buffering systems. The standard acidity parameter, the Base Neutralization
Capacity (BNC) is determined by endpoint titration, and reflects a cumulative parameter of both hydrogen ions and all buffering
systems, but does not give information on the individual buffer systems. We demonstrate that a detailed interpretation of
titration curves can provide information about the strength of the buffering systems. The buffering systems are of importance
for environmental studies and treatment of acidic mining waters.
Methods Titrations were carried out by means of an automatic titrator using acidic mining waters from Germany and Canada. The curves
were interpreted, compared with each other, to endpoint titration results and to elemental concentrations contained therein.
Results and Discussion The titration curves were highly reproducible, and contained information about the strength of the buffer systems present.
Interpretations are given, and the classification and comparison of acidic mining waters, by the nature and strength of their
buffering systems derived from titration curves are discussed. The BNC-values calculated from the curves were more precise
than the ones determined by the standard endpoint titration method. Due to the complex buffer mechanisms in acidic mining
waters, the calculation of major metal concentrations from the shape of the titration curve resulted in estimates, which should
not be confused with precise elemental analysis results.
Conclusion Titration curves provide an inexpensive, valuable and versatile tool, by which to obtain sophisticated information of the
acidity in acidic water. The information about the strength of the present buffer systems can help to understand and document
the complex nature of acidic mining water buffer systems. Finally, the interpretation of titration curves could help to improve
treatment measurements and the ecological understanding of these acidic waters. 相似文献
525.
526.
广州市酸沉降对材料破坏的经济损失估算 总被引:3,自引:0,他引:3
大气中的酸性物质对材料的破坏是酸沉降经济损失中的重要部分。简要说明了材料损失的计算方法,并以2001年为基准年,选择了广州市作为代表性城市,运用材料损伤函数和材料使用寿命公式对建筑材料及自行车的经济损失进行了估算,使酸沉降的破坏作用达到定量化。 相似文献
527.
528.
529.
草酸作用下海洋疏浚物中Cr的释放动力学研究 总被引:1,自引:0,他引:1
采用恒温振荡实验装置,系统研究了有机酸草酸降解海洋疏浚物中重金属Cr的动力学过程。结果表明,恒温振荡6 h后,浓度为0.05~0.4 mol/L的草酸可使Cr的释放百分率达到24%~44%。Cr的释放总体上可分为快速反应和慢速反应2个阶段,0~2 h为快反应阶段,解吸速率快,2~6 h后为慢反应阶段。草酸对Cr的释放动力学数据可用双常数方程很好的拟合,说明在草酸的存在下,疏浚物颗粒表面对Cr的释放可能更多表现出能量的不均匀性。温度升高时Cr的解吸量增加,反应速度加快,根据阿累尼乌斯公式估算出的活化能为26.53 kJ/mol。 相似文献
530.