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951.
952.
在分析金沙江(云南段)环境现状和“十五”期间水质发展变化的基础上,提出金沙江(云南段)水环境保护的思路和实施重点。 相似文献
953.
954.
文山县饮用水水源铁锰超标调查研究、处理方法及建议 总被引:1,自引:0,他引:1
结合文山县当前饮用水源中铁锰超标的实际情况,分析了周边环境对文山县饮用水水源地的影响,阐述了饮用水中铁、锰超标对人体健康的危害,提出了解决饮用水中铁锰超标问题的必要性和可行方法,并提出相关的对策和建议。 相似文献
955.
G. K. Parshetti S. G. Parshetti A. A. Telke D. C. Kalyani R. A. Doong P. Govindwar 《环境科学学报(英文版)》2011,23(8):1384-1393
Agrobacterium radiobacter MTCC 8161 completely decolorized the Crystal Violet with 8 hr (10 mg/L) at static anoxic conditions.
The decreased decolorization capability by A. radiobacter was observed, when the Crystal Violet concentration was increased
from 10 to 100 mg/L. Semi-synthetic medium containing 1% yeast extract and 0.1% NH4Cl has shown 100% decolorization of
Crystal Violet within 5 hr. A complete degradation of Crystal Violet by A. radiobacter was observed up to 7 cycles of repeated
addition (10 mg/L). When the effect of increasing inoculum concentration on decolorization of Crystal Violet (100 mg/L) was
studied, maximum decolorization was observed with 15% inoculum concentration. A significant increase in the activities of laccase
(184%) and aminopyrine N-demethylase (300%) in cells obtained after decolorization indicated the involvement of these enzymes
in decolorization process. The intermediates formed during the degradation of Crystal Violet were analyzed by gas chromatography
and mass spectroscopy (GC/MS). It was detected the presence of N,N,N′,N′′-tetramethylpararosaniline, [N; N-dimethylaminophenyl]
[N-methylaminophenyl] benzophenone, N; N-dimethylaminobenzaldehyde, 4-methyl amino phenol and phenol. We proposed the
hypothetical metabolic pathway of Crystal Violet biodegradation by A. radiobacter. Phytotoxicity and microbial toxicity study showed
that Crystal Violet biodegradation metabolites were less toxic to bacteria (A. radiobacter, P. aurugenosa and A. vinelandii) contributing
to soil fertility and for four kinds of plants (Sorghum bicolor, Vigna radiata, Lens culinaris and Triticum aestivum) which are most
sensitive, fast growing and commonly used in Indian agriculture. 相似文献
956.
Michael A. Butkus Jon C. Malinowski 《Journal of the American Water Resources Association》2023,59(1):197-211
Comprehensive analyses of long-term region-specific water resources developments could offer new insights for contemporary water resources planners and decision makers. The objective of this work was to analyze water supply development at the United States Military Academy (USMA) during the 19th and early 20th Centuries through the lens of selected modern water resources planning and management practices. Analysis of water usage, population, and technological growth revealed that changes in technology had a greater influence on total water withdrawals than an increase in population. The USMA water supply system evolved incrementally over much of the 141-year study period and failure to adequately recognize shortcomings in water supply options resulted in several suboptimal decisions. Communications and enhanced stakeholder participation might have resulted in alternative decisions. 相似文献
957.
The interaction between a cationic dye Methylene Blue (MB) and an anionic surfactant sodium dodecyl sulfate (SDS) with the presence of Cd2+ was investigated spectrophotometrically in a certain concentration range. The spectrophotometric measurements of dye-metal ion-surfactant system were carried out. The results indicated that the SDS concentration had a significant influence on the dye spectrum, while the addition of Cd2+ hardly caused change of the maximum value of absorbance. According to this observation, we concluded that electrostatic and hydrophobic interaction between dye and surfactant occurred up to a certain level, and the homo-ions Cd2+ almost exerted no effect on the dye-surfactant complexation, establishing a theoretical foundation for simultaneous removal of organic dye and heavy metal using foam fractionation. Meanwhile, the effects of their interaction on foam performance were investigated. The results showed that the addition of Cd2+ favored the tendency to ameliorate foam properties just contrary to MB. The feasibility of foam separation for dye and heavy metal removal from simulated wastewater was also confirmed using a continuous foam fractionator. In the simultaneous removal process, with the initial SDS concentration ranging from 0.5 to 5.0 mmol/L, the maximum removal efficiencies of MB and Cd2+ were obtained as 99.69% and 99.61%, respectively. The enrichment ratios were reduced from 24.34 to 7.65 for MB and from 22.01 to 3.35 for Cd2+. 相似文献
958.
959.
Heeyeun Yoon 《Journal of Environmental Planning and Management》2018,61(7):1113-1136
This study aimed to unpack the dynamic proximity effects of a park on residential values in the urban regeneration context: first by the development phase of the park, and second, by specific characteristics of the residential units. The study site is the Dream Forest in Seoul, South Korea, and the study period is from 2006 to 2015. The two-fold multilevel regression analysis suggests that the Dream Forest began exerting proximity effects from the time of site acquisition by the city, which peaked at a 3.7% price increment per 100-meter distance to the park from a prototypical housing unit, soon after the public announcement of the park procurement plan. During construction, inauguration and stabilization, the effect has remained at around 3.0%. The analysis also suggests that the proximity effect applies unevenly to housing units: apartment type or older housing units are more sensitive to the externality effects than their counterparts – multifamily type or newer housing units. 相似文献
960.
煤层注水抑制瓦斯解吸效应试验研究 总被引:4,自引:0,他引:4
煤层注水宏观上具有疏松煤体、卸压排放瓦斯的效应,这是人们对煤层防突机理的初步认识。为进一步认清煤层防突机理,采用实验室试验和现场测试相结合的方法,在实验室中使干燥煤样在煤样罐中预先吸附瓦斯来模拟原始煤层,然后向试验煤样高压注入水分,注水后再测试瓦斯解吸等温特性曲线、瓦斯解吸速度及残存瓦斯含量。测验结果表明,注水后瓦斯解吸等温特性曲线上移,初始瓦斯解吸速度变小且衰减速度变慢,残存瓦斯含量增加,现场测试钻屑瓦斯解吸指标值降低。通过分析测试结果认为,注水后,水分进入并留存在煤体的微孔隙中,对煤层瓦斯具有抑制解吸效应,而抑制解吸效应可以降低瓦斯初始解吸速度,使瓦斯解吸过程变缓,避免瓦斯突然快速解吸。这是煤层注水防治煤与瓦斯突出的一项重要机理。 相似文献