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991.
Fate and transformation of naphthylaminesulfonic azo dye Reactive Black 5 during wastewater treatment process 总被引:1,自引:0,他引:1
Xingzu Wang Xiang Cheng Dezhi Sun Yiwei Ren Guihua Xu 《Environmental science and pollution research international》2014,21(8):5713-5723
Certain aromatic amines generated by the decolorization of some azo dyes are not removed substantially by conventional anaerobic–aerobic biotreatment. These aromatic amines are potentially toxic and often released in the wastewater of industrial plants. In this study, the fate and transformation of the naphthylaminesulfonic azo dye Reactive Black 5 (RB5) during different phases of a sequencing batch reactor were investigated. The major products of RB5 decolorization during the anaerobic phase include 2-[(4-aminophenyl)sulfonyl]ethyl hydrogen sulfate (APSEHS) and 1-2-7-triamino-8-hydroxy-3-6-naphthalinedisulfate (TAHNDS). During the aerobic phase, APSEHS was hydrolyzed and produced 4-aminobenzenesulfonic acid, which was further degraded via dearomatization. TAHNDS was transformed rapidly via auto-oxidation into TAHNDSDP-1 and TAHNDSDP-2, which were not further removed by the activated sludge during the entire 30-day aerobic phase. In contrast, different behaviors of TAHNDS were observed during the anoxic phase. The transformation of TAHNDS was initiated either by deamination or desulfonation reaction. TAHNDS was then converted into 3,5-diamino-4-hydroxynaphthalene-2-sulfonic acid, which was subsequently removed via ring cleavage reaction under aerobic condition. In conclusion, complete degradation of TAHNDS by activated sludge occurs only during anoxic/aerobic processes instead of the conventional anaerobic/aerobic processes. 相似文献
992.
为了提高厌氧流化床微生物燃料电池(AFB-MFC)的性能,并为双室MFC寻找价廉、易得、无污染的阴极液,在曝气量16~24 L/h、温度(35±2)℃、回流量10.2 L/h、阴极底边距阴极室内底部17.3 cm、外电阻250 Ω、水力停留时间(HRT)14.0~14.9 h以及进水pH 7.81~8.37下,研究了阴极液及底物浓度对系统产电及废水处理性能的影响。结果表明,使用缓冲溶液、阳极室出水和自来水作阴极液时,自来水的产电性能最佳,阴极液种类不影响系统有机基质的去除。以自来水为阴极液时,阴极液pH及电导率随运行时间增加而增加,COD去除率为80.11%~89.29%,输出电压及功率密度开始随运行时间增加而增加,之后稳定在440~452 mV和48.40~51.08 mW/m2之间。增加底物浓度对COD去除率影响不大,而输出电压及功率密度随底物浓度增加而下降;底物COD浓度由3 307.09 mg/L增至9 520 mg/L时,COD去除率在85.77%~94.44%之间,输出电压及功率密度则分别由449 mV和50.40 mW/m2下降至406 mV和41.21 mW/m2。自来水作阴极液可避免二次污染及阴极液对阳极室微生物的影响,并得到高的产电能力。 相似文献
993.
Gas–particle concentration,distribution, and health risk assessment of polycyclic aromatic hydrocarbons at a traffic area of Giza,Egypt 总被引:1,自引:0,他引:1
Atmospheric particulate and gaseous polycyclic aromatic hydrocarbons (PAHs) samples were collected from an urban area in Dokki
(Giza) during the summer of 2007 and the winter of 2007–2008. The average concentrations of PAHs were 1,429.74 ng/m3 in the particulate phase, 2,912.56 ng/m3 in the gaseous phase, and 4,342.30 ng/m3 in the particulate + gaseous phases during the period of study. Dokki has high level concentrations of PAH compounds compared
with many polluted cities in the world. The concentrations of PAH compounds in the particulate and gaseous phases were higher
in the winter and lower in the summer. Total concentrations of PAHs in the particulate phase and gaseous phase were 22.58%
and 77.42% in summer and 36.97% and 63.03% in winter of the total (particulate + gaseous) concentrations of PAHs, respectively.
The gaseous/particulate ratios of PAHs concentration were 3.43 in summer and 1.71 in winter. Significant negative correlation
coefficients were found between the ambient temperature and concentrations of the total PAHs in the particulate and gaseous
phases. The distribution of individual PAHs and different categories of PAHs based on aromatic ring number in the particulate
and gaseous phases during the summer and winter were nearly similar, indicating similar emission sources of PAHs in both two
seasons. Benzo(b)fluoranthene in the particulate phase and naphthalene in the gaseous phase were the most abundant compounds. Diagnostic concentration
ratios of PAH compounds indicate that these compounds are emitted mainly from pyrogenic sources, mainly local vehicular exhaust
emissions. Health risks associated with the inhalation of individual PAHs in particulate and gaseous phases were assessed
on the basis of its benzo(a)pyrene equivalent concentration. Dibenzo(a,h)anthracene and benzo(a)pyrene in the particulate phase and benzo(a)pyrene and benzo(a)anthracene in the gaseous phase were the greatest contributors to the total health risks. The relative mean contributions
of the total carcinogenic activity (concentrations) of all PAHs to the total concentrations of PAHs were 29.37% and 25.15%
in the particulate phase and 0.76% and 0.92% in the gaseous phase during the summer and winter, respectively. These results
suggest that PAHs in the particulate phase in the ambient air of Dokki may pose a potential health risk. 相似文献
994.
为了研究曝气池空间内水质的分布及变化规律,采用了YSI6600 V2多参数水质检测仪对成都市三瓦窑污水处理厂的一期工程传统污泥法(CAS)、二期工程缺氧、好氧和内源呼吸(AOE)工艺中的曝气池分别进行了包括DO、NH3-N、NO3--N、pH、氯化物和温度等水质指标的场的检测,通过分析这些数据,揭示了曝气池内部水质变化的规律,并比较了CAS工艺与AOE工艺内水质处理效果的差别。结果表明,(1)溶解氧沿池深方向呈现出一定的分布规律,CAS工艺中随池深增加,溶解氧增加,AOE工艺中随着池深的增加,溶解氧降低;(2)AOE工艺对氨氮在O区的去除率可达97.64%,明显高于CAS工艺的41.76%;(3)沿曝气池长度测量溶解氧空间分布规律,参照理论曲线及依据水质处理要求,调整曝气量的方法具有长期运行经济、水质处理效果好的特点。 相似文献
995.
Ellen Sträter Anna Westbeld Otto Klemm 《Environmental science and pollution research international》2010,17(9):1563-1573
Background
The Atacama Desert in Northern Chile is one of the most arid places on earth. However, fog occurs regularly at the coastal mountain range and can be collected at different sites in Chile to supply settlements at the coast with freshwater. This is also planned in the fog oasis Alto Patache (20°49′S, 70°09′W). For this pilot study, we collected fog water samples in July and August 2008 for chemical analysis to find indications for its suitability for domestic use. 相似文献996.
Mark Purdon 《Environment, Development and Sustainability》2010,12(6):1025-1050
Negotiations of the Kyoto Protocol reached what has been called a moral position on biocarbon sinks which saw important limitations
on their use in the Clean Development Mechanism (CDM), the Protocol’s main carbon offset system. After outlining this moral
position, this article examines the consequences of these limitations on the viability of community forest participation in
the CDM through a case study of three community forests in West Africa. Results suggest that there is significant carbon mitigation
potential from forest conservation, reforestation as well as from improved fuelwood cookstoves at the community level. Yet
under the current rules of the CDM, little of this overall carbon mitigation potential is able to be realized. Using qualitative
research methodologies, it was learned that community respondents showed a pragmatic, yet cautious interest in the CDM while
also emphasizing a need for land-use flexibility. The paper closes with a political discussion of the “‘moral position” on
biocarbon sinks in the carbon market and concludes with policy recommendations for biocarbon sinks, in both the CDM and REDD,
in the post-Kyoto climate change regime. 相似文献
997.
There is much discussion within the sustainable development community regarding climate stabilization and particularly, finding
environmentally equitable ways to address emission reductions. Knowing the current level of emission is only one variable
in this complex picture. While the rate of emissions is clearly a problem, the overall increase in GHG concentration in the
atmosphere is ultimately the main driver of anthropogenic warming. Therefore, it is also important to understand the cumulative
emissions, those which have taken us to the current condition. This research presents a case study of six countries to compare
the emissions per capita and cumulative emissions during the past 200 years. It is known that carbon emissions are closely
related to economic activities, but here we show that some countries have reached per capita emissions plateaus at different
levels while others are still rising. Specifically, one approach toward socioeconomic development, in terms of energy–economy,
reaches a plateau at 10 Mt carbon per person, which the United Kingdom and South Korea have attained. The US occupies another
emission regime at 20 Mt carbon per person. Developing economies such as India and China are considerably below these levels,
and unless they follow other integrated economic/environmental solutions, they will continue to increase their per capita
emissions during development. 相似文献
998.
Yu-Yang Long Li-Fang Hu Jing Wang Cheng-Ran Fang Ruo He Dong-Sheng Shen 《Environmental science and pollution research international》2010,17(9):1539-1546
Purpose
To protect the environmental quality of soil, groundwater, and surface water near the landfill site, it is necessary to make an accurate assessment of the heavy metal mobility. This study aims to present the bio-immobilization behavior of heavy metals in landfill and provide some reference suggestion for the manipulation of heavy metal pollution control after closure. 相似文献999.
Torben R. Christensen Marcin Jackowicz-Korczyński Mika Aurela Patrick Crill Michal Heliasz Mikhail Mastepanov Thomas Friborg 《Ambio》2012,41(3):207-217
This article reports a dataset on 8 years of monitoring carbon fluxes in a subarctic palsa mire based on micrometeorological eddy covariance measurements. The mire is a complex with wet minerotrophic areas and elevated dry palsa as well as intermediate sub-ecosystems. The measurements document primarily the emission originating from the wet parts of the mire dominated by a rather homogenous cover of Eriophorum angustifolium. The CO2/CH4 flux measurements performed during the years 2001–2008 showed that the areas represented in the measurements were a relatively stable sink of carbon with an average annual rate of uptake amounting to on average ?46 g C m?2 y?1 including an equally stable loss through CH4 emissions (18–22 g CH4–C m?2 y?1). This consistent carbon sink combined with substantial CH4 emissions is most likely what is to be expected as the permafrost under palsa mires degrades in response to climate warming. 相似文献
1000.
Virender K. Sharma Nigel J. D. Graham Xiang-Zhong Li Bao-Ling Yuan 《Environmental science and pollution research international》2010,17(2):453-461