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991.
膜生物反应器中新型无纺布膜过滤特性及膜污染特征 总被引:1,自引:1,他引:0
通过无纺布和聚偏氟乙烯平板膜组件在相同操作条件下的对比实验,研究无纺布膜的过滤特性。结果表明,2种膜的膜生物反应器COD、氨氮平均去除率均>90%。过膜压力变化表明在长期运行条件下,无纺布可适于作为膜生物反应器的过滤介质,其过滤机理为膜表面滤饼层形成动态膜,从而增强了膜截留能力。膜污染研究表明,无纺布膜阻力主要来自滤饼层(占总阻力的83.6%),经清洗后膜通量可恢复至94%。扫描电镜显示膜表面滤饼层较厚,结合膜阻力分析结果认为,该滤饼层对膜污染和可逆性影响较大。对膜表面和膜孔中胞外聚合物(EPS)的红外分析证实,其中含有蛋白质和多糖物质,而且组分分析表明蛋白质是膜污染物EPS中的主要组分,在膜孔中的含量比滤饼层中还高。 相似文献
992.
Li R. Gao Dan. Xia Hai Z. Tian Hai J. Zhang Li D. Liu Yi W. Wang 《Journal of environmental science and health. Part. B》2013,48(5):322-330
Organochlorine pesticides (OCPs) were analyzed in 26 surface sediment samples from the Liaohe River basin, and the distributions of and potential environmental risks posed by OCPs in the basin were evaluated. Eighteen OCPs listed in the Stockholm Convention were determined using isotope-dilution gas chromatography–high resolution mass spectrometry. This is the first study of hexachlorobenzene (HCB) in the Liaohe River basin sediments. The total OCP concentrations were 0.39–68.06 ng g?1 dry weight. The total α-, β-, γ-, and δ-hexachlorocyclohexane (HCH), the total dichlorodiphenyltrichloroethane (DDT – p,p′-dichlorodiphenyldichloroethane (DDD), p,p′-dichlorodiphenyldichloroethylene (DDE), o,p'-DDT, and p,p′-DDT), and the HCB concentrations in the sediment samples were 0.1–28.48 ng g?1 (mean 4.01 ng g?1), 0.08–6.52 ng g?1 (mean 3.07 ng g?1), and 0.18–24.8 ng g?1 (mean 4.38 ng g?1), respectively. The HCB concentrations were higher than the concentrations of the other OCPs, and the HCHs and HCB together were the dominant OCPs. β-HCH was the most abundant HCH isomer. The concentrations of DDTs and other OCPs were relatively low, and the (DDE+DDD)/DDT ratios (>0.5) and DDD/DDE ratios (<1) indicated that no recent DDT inputs had occurred in the Liaohe River system. The main sources of HCHs were probably the historical production and agricultural use of HCH in the study area. The DDT and HCH concentrations were generally below or similar to the concentrations that have been found in other parts of the world. An ecotoxicological evaluation indicated that HCHs in surface sediments pose slight risks to human and ecological health in the Liaohe River basin. 相似文献
993.
超细粉煤灰基成型吸附剂的动态吸附实验 总被引:2,自引:1,他引:1
以粉煤灰为原料制备成型吸附剂,对水溶液中亚甲基蓝和Cr6+进行动态吸附研究,绘制穿透曲线,利用Origin软件对实验数据分析处理,得出穿透曲线的通式Ct=A1-A2〖〗1+(t/t0)p+A1。结果表明,初始浓度C0=25 mg/L,填料高度不同时,达到穿透点的时间随填料高度的增加而增加;填料高度h=200 mm,初始浓度不同时,达到穿透点的时间随初始浓度的增加而减小;该吸附剂对有机染料和重金属离子均有较好的吸附性能;穿透曲线通式的回归线性相关系数表明,该通式可很好地反映超细粉煤灰成型吸附剂的动态吸附过程。 相似文献
994.
Castello L Viana JP Watkins G Pinedo-Vasquez M Luzadis VA 《Environmental management》2009,43(2):197-209
Fishers and small-scale fisheries worldwide have been marginalized historically. Now it is clear that integrating fishers
in management processes is key to resource conservation, but it is less clear how to do it. Here, based on a literature review and new information, we present and analyze a case in which the participation
of fishers in the management process was crucial in recovering an overexploited small-scale fishery for the pirarucu (Arapaima spp.) in the Amazon Basin, Brazil. In 8 years of experimental management, from 1999 to 2006, the population of pirarucu increased
9-fold (from about 2200 to 20,650 individuals), harvest quotas increased 10-fold (from 120 to 1249 individuals), and fishers’
participation in the management process increased and they benefited from increased monetary returns. Additionally, the number
of communities conducting the management scheme increased from 4 in 1999 to 108 in 2006, following the demands of fishers
and regional government agencies. Based on our analysis, we suggest that the participation of fishers in the management of
other small-scale fisheries in the world can be improved by focusing on (1) applying the knowledge and skills of fishers in
resource monitoring and management, (2) bridging knowledge systems among all involved stakeholders, (3) collaborating with
fishers that are interested in, and capable of conducting, resource conservation schemes, and (4) conducting management under
conditions of uncertainty. 相似文献
995.
对国内外利用废水处理等工业过程中所产生的污泥作为生物吸附剂吸附水体中重金属的研究现状进行了综述和分析,包括其预处理技术、反应机理、主要影响因素、处理效果以及反应器工艺等。同时,对该技术未来的发展趋势进行了展望,指出依托现有废水处理设施进行集约化开发将是该工艺的发展方向。 相似文献
996.
997.
Ivan S. Ristić Ljiljana Tanasić Ljubiša B. Nikolić Suzana M. Cakić Olivera Z. Ilić Radmila Ž. Radičević Jaroslava K. Budinski-Simendić 《Journal of Polymers and the Environment》2011,19(2):419-430
Different synthesis methods were applied to determine optimal conditions for polymerization of (3S)-cis-3,6-dimethyl-1,4-dioxane-2,5-dione (l-lactide), in order to obtain poly(l-lactide) (PLLA). Bulk polymerizations (in vacuum sealed vessel, high pressure reactor and in microwave field) were performed
with tin(II) 2-ethylhexanoate as the initiator. Synthesis in the vacuum sealed vessel was carried out at the temperature of
150 °C. To reduce the reaction time second polymerization process was carried out in the high pressure reactor at 100 °C and
at the pressure of 138 kPa. The third type of rapid synthesis was done in the microwave reactor at 100 °C, using frequency
of 2.45 GHz and power of 150 W at the temperature of 100 °C. The temperature in this method was controlled via infrared system
for in-bulk measuring. The solution polymerization (with trifluoromethanesulfonic acid as initiator) was possible even at
the temperature of 40 °C, yielding PLLA with narrow molecular weight distribution in a very short period of time (less than
6 h). The obtained polymers had the number-average molecular weights ranging from 43,000 to 178,000 g mol−1 (polydispersity index ranging from 1 to 3) according to the gel permeation chromatography measurements. The polymer structure
was characterized by Fourier transform infrared and NMR spectroscopy. Thermal properties of the obtained polymers were investigated
using thermogravimetry and differential scanning calorimetry. 相似文献
998.
Burskyte V Belous O Stasiskiene Z 《Environmental science and pollution research international》2011,18(5):716-726
Introduction
In 2003, the Japan International Cooperation Agency carried out a development feasibility study of Klaipeda Seaport (Lithuania). The focus in this study was the evaluation of environmental impacts of the port expansion because it is located in an ecologically sensitive area. While the Japanese researchers focused on the environmental impact analysis, they did not provide unambiguous conclusions. The problems remained unresolved and required further, more detailed consideration and deeper analysis. 相似文献999.
Silvana Kuhtz 《Environment, Development and Sustainability》2011,13(1):79-85
Climate is one of the more complex physical systems in nature, its behaviour being fundamentally non-linear and chaotic. In
assessing the potential risks from climate change and the costs of averting it, researchers and policymakers encounter pervasive
uncertainty. Sceptics demand to get rid of the inherent uncertainties, and some experts, on the other end, keep sending out
messages of catastrophic scenarios hoping that this will increase people’s awareness of the danger we face. The recent admission
of a mistake in IPCC’s Climate change 2007 report (promptly broadcast by all the major media groups and newspapers from Jan. 20th 2010 onwards) made by the head of
the Intergovernmental Panel on Climate Change—that Himalayan glaciers could melt away by 2035 (the IPCC claim of 2035 is wrong
by over 300 years.)—has already brought a damage to the IPCC’s reputation that is likely to be considerable. But in this paper,
perhaps risking being provocative and paradoxical, instead of looking for the right answers to what we think are inevitable uncertainties, we intend to search for new questions that may lead to a new way of
thinking and may bring about new lifestyles and behaviour for citizens and firms. 相似文献
1000.
Adaptive maritime spatial planning (MSP) uses monitoring and evaluation of the effectiveness of spatial and temporal management
measures to promote understanding and improve planning and decision-making. An adaptive approach to MSP involves exploring
alternative ways to meet management objectives, predicting the outcomes of alternative management measures, implementing one
or more of these alternative management measures, monitoring to learn about the effects of management measures, and then using
the results to update knowledge and adjust management actions. A monitoring and evaluation plan should be designed to be both
cost effective and comprehensive. The process of setting and assessing performance metrics requires that the ecological and
socio-economic objectives of the spatial management plan must be clearly stated up front for management actions to reflect
those objectives accurately. To evaluate the effectiveness of a MSP plan, a range of ecological, socio-economic and institutional
indicators need to be developed and monitored. 相似文献