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101.
电化学还原-氧化工艺降解4-氯酚的毒性研究 总被引:1,自引:1,他引:0
采用紫外光还原法制备了Pd-Fe/石墨烯催化阴极,并以Ti/IrO_2/RuO_2为阳极,构成三电极体系(双阴极)和两电极体系(单阴极)的电化学还原-氧化降解工艺,分别对4-氯酚进行降解.采用离子色谱、高效液相色谱、TOC仪对4-氯酚降解过程中中间产物及其浓度进行测定.根据公式计算降解过程中理论计算毒性值,应用发光细菌法测定降解过程中的实际毒性值,对理论计算毒性值与实际毒性值进行比较,分析不同体系下降解过程中毒性的变化规律.结果表明,两种工艺体系在最佳降解条件下,阴极室毒性均呈下降的趋势,由于降解过程中在阳极室生成高毒性的苯醌,阳极室毒性均先升高后降低.通过相关性分析得到,两种体系理论计算毒性与实际毒性在P=0.01水平下,相关性系数均为1,显著相关,表明降解过程中实际毒性的测定结果真实可靠.降解至120 min时,三电极体系毒性小于两电极体系,表明三电极体系优于两电极体系.据此提出实际毒性测定方法在电化学还原-氧化工艺降解氯酚类有机废水毒性测试的工业应用中有着广泛的前景. 相似文献
102.
对臭氧氧化去除饮用水中微囊藻毒素RR及LR的降解效能、反应动力学进行了试验研究,讨论了藻毒素初始质量浓度、pH值、羟基自由基(·OH)抑制剂(HCO-3)、溶解性有机碳(DOC)质量浓度对降解的影响.结果表明:整个降解过程符合一级动力学反应方程,降解速率常数与藻毒素初始质量浓度无关;pH值的升高、HCO-3和DOC的存在都会降低藻毒素的降解效率.在液相臭氧质量浓度为8.20 mg·L-1,pH=7.0,温度为(25±1) ℃,反应时间30 min的条件下,MC-RR降解速率常数k=7.80×102 min-1,去除率达90.0%;MC-LR降解速率常数k=1.06×101 min-1,去除率达96.3%. 相似文献
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Feng Qin Shujuan Wang Inna Kim Hallvard F. Svendsen Changhe Chen 《International Journal of Greenhouse Gas Control》2011,5(3):405-412
A reaction calorimeter was used to determine the enthalpies of absorption of CO2 in aqueous ammonia and in aqueous solutions of ammonium carbonate at temperatures of 35–80 °C. The heat of absorption of CO2 with 2.5 wt% aqueous ammonia solution was found to be about 70 kJ/mol CO2, which is lower than that with MEA (around 85 kJ/mol) at 35 and 40 °C. The value decreases with increased loading, but not to as low a value as expected by the carbonate–bicarbonate reaction (26.88 kJ/mol). The enthalpy of absorption of CO2 in aqueous ammonia at 60 and 80 °C decreases with loadings at first, then increases between 0.2 mol CO2/mol NH3 and 0.6 mol CO2/mol NH3, and then decreases again. The behavior of the heat of absorption of CO2 in 10 wt% ammonium carbonate solution was found to be the same as that of aqueous ammonia at loadings above 0.6 mol CO2/mol NH3. The heat of absorption increases with increasing temperature. The heats of absorption are directly related to the extent of the various reactions with CO2 and can be assessed from the species variation in the liquid phase. 相似文献
105.
J.X. Wen A. HeidariS. Ferraris V.H.Y. Tam 《Journal of Loss Prevention in the Process Industries》2011,24(2):187-193
A modelling strategy has been developed for consequence analysis of medium and large scale gaseous detonation. The model is based on the solution of Euler equations with one-step chemistry. The Van Leer flux limited method which is a total variation diminishing scheme is used for shock capturing. Preliminary calculations were firstly conducted for small domains with fine grids which resolve the wave, relatively coarse grids which have less than 10 grids across the wave and coarse grids in which the minimum grid size is larger than the wave thickness to ensure that the reaction scheme has been properly tuned to capture the correct detonation pressure, temperature and velocity in the resolutions used in the different cases. The model was firstly tested against a medium scale detonation test in a shock tube with U-bends. Reasonably good agreement is achieved on detonation pressure and mean shock wave velocities at different measuring segments of the tube. Following the validation, the detonation of a hypothetical planar propane-air cloud is simulated. The predictions uncovered some interesting features of such large scale detonation phenomena which are of significance in the safety context, especially for accidental investigations. The findings from the present analysis are in line with the forensic evidence on damages in some historic accidents and challenges previous analysis of a major accident in which forensic evidence suggested localised detonation but was considered as the consequence of fire storms by the investigation team. 相似文献
106.
Green shipping practices in the shipping industry: Conceptualization, adoption, and implications 总被引:1,自引:0,他引:1
Kee-Hung Lai Venus Y.H. LunChristina W.Y. Wong T.C.E. Cheng 《Resources, Conservation and Recycling》2011,55(6):631-638
There have been increasing concerns about the adverse impacts on the environment caused by cargo movement in international trade. Different stakeholders ranging from shippers and carriers to government bodies and international communities have expressed worries about the environmental impacts brought by shipping related activities. The pollution and waste created in the shipping processes have imposed environmental burdens and accelerated resource depletion. The situation is set to worsen in the face of intensifying trade globalization, which has contributed to sustained growth in international shipping activities. To help protect the environment, many shipping firms have taken the initiative to find ways to lessen the environmental damage of their operations while enhancing their performance. The objective of this study is to examine the environmental awareness and the environmental measures taken in the shipping industry. We propose a conceptual framework for evaluating green shipping practices and develop several propositions stating the conditions under which shipping firms would behave in an environmentally responsible manner. We conclude with managerial and policy implications of the conceptual framework to promote green shipping practices in the shipping industry. 相似文献
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古村落是一种独特的人文旅游资源,对其游憩价值进行量化评估可为景区(点)的旅游开发和资源保护提供科学依据.基于问卷调查,利用经典的资源价值评估方法--旅行费用法对宏村古村落旅游资源2008年的国内游憩价值进行了核算,结果为23593.14万元,在此基础上对TCM的核算过程进行了评价. 相似文献
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