首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到20条相似文献,搜索用时 0 毫秒
1.
The burning rate of a slick of oil on a water bed is characterized by three distinct processes, ignition, flame spread and burning rate. Although all three processes are important, ignition and burning rate are critical. The former, because it defines the potential to burn and the latter because of the inherent possibility of boilover. Burning rate is calculated by a simple expression derived from a one-dimensional heat conduction equation. Heat feedback from the flame to the surface is assumed to be a constant fraction of the total energy released by the combustion reaction. The constant fraction (χ) is named the burning efficiency and represents an important tool in assessing the potential of in situ burning as a counter-measure to an oil spill. By matching the characteristic thermal penetration length scale for the fuel/water system and an equivalent single layer system, a combined thermal diffusivity can be calculated and used to obtain an analytical solution for the burning rate. Theoretical expressions were correlated with crude oil and heating oil, for a number of pool diameters and initial fuel layer thickness. Experiments were also conducted with emulsified and weathered crude oil. The simple analytical expression describes well the effects of pool diameter and initial fuel layer thickness permitting a better observation of the effects of weathering, emulsification and net heat feedback to the fuel surface. Experiments showed that only a small fraction of the heat released by the flame is retained by the fuel layer and water bed (of the order of 1%). Ignition has been studied to provide a tool that will serve to assess a fuels ease to ignite under conditions that are representative of oil spills. Two different techniques are used, piloted ignition when the fuel is exposed to a radiant heat flux and flash point as measured by the ASTM D56 Tag Closed Cup Test. Two different crude oils were used for these experiments, ANS and Cook Inlet. Crude oils were tested in their natural state and at different levels of weathering, showing that piloted ignition and flash point are strong functions of weathering level.  相似文献   

2.
3.
This research note summarizes Spartina alterniflora and Sagittaria lancifolia sensitivity to oiling and in situ burning of applied oil. Experimental plots (2.4 m × 2.4 m × 0.6 m) were constructed in salt and freshwater marsh habitats and South Louisiana Crude (SLC) applied (2 l m−2) to stems and leaves of marsh plants of oil and oil/burn treatment plots. Burning was initiated mid-August when winds were calm and a 15-25 cm floodwater layer covered the marsh substrate. Vegetative responses (stem density, height, carbon assimilation and biomass production) were measured for approximately one year following the in situ burns. Application of oil and burning of SLC only had short-term detrimental effects on salt and freshwater marsh vegetation. About one year after burns, vegetative responses measured in oiled and oiled/burned plots approached or exceeded control (no oil or burn) values. Field results suggest, under our experimental conditions, in situ burning of spilled oil in S. alterniflora and S. lancifolia marshes may be a remediation operation to consider.  相似文献   

4.
油浴预蒸馏-流动注射光度法在线测定水中挥发酚   总被引:1,自引:0,他引:1  
基于流动注射(FIA)理论和酚与4-氨基安替比林显色反应原理,利用可编程控制器,自主组装出可自动在线监测挥发酚的分析仪.首次采用油浴预蒸馏方法,达到在线定量分离的目的.在最优条件下,体系吸光度值与挥发酚质量浓度在0~ 3.00 mg/L范围内呈现良好的线性关系,线性回归方程为A=0.08799ρ+0.00231 (n=...  相似文献   

5.
In situ burning is an oil spill response technique or tool that involves the controlled ignition and burning of the oil at or near the spill site on the surface of the water or in a marsh (see Lindau et al., this volume). Although controversial, burning has been shown on several recent occasions to be an appropriate oil spill countermeasure. When used early in a spill before the oil weathers and releases its volatile components, burning can remove oil from the waters surface very efficiently and at very high rates. Removal efficiencies for thick slicks can easily exceed 95% (Advanced In Situ Burn Course, Spiltec, Woodinville, WA, 1997). In situ burning offers a logistically simple, rapid, inexpensive and if controlled a relatively safe means for reducing the environmental impacts of an oil spill. Because burning rapidly changes large quantities of oil into its primary combustion products (water and carbon dioxide), the need for collection, storage, transport and disposal of recovered material is greatly reduced. The use of towed fire containment boom to capture, thicken and isolate a portion of a spill, followed by ignition, is far less complex than the operations involved in mechanical recovery, transfer, storage, treatment and disposal (The Science, Technology, and Effects of Controlled Burning of Oil Spills at Sea, Marine Spill Response Corporation, Washington, DC, 1994).However, there is a limited window-of-opportunity (or time period of effectiveness) to conduct successful burn operations. The type of oil spilled, prevailing meteorological and oceanographic (environmental) conditions and the time it takes for the oil to emulsify define the window (see Buist, this volume and Nordvik et al., this volume). Once spilled, oil begins to form a stable emulsion: when the water content exceeds 25% most slicks are unignitable. In situ burning is being viewed with renewed interest as a response tool in high latitude waters where other techniques may not be possible or advisable due to the physical environment (extreme low temperatures, ice-infested waters), or the remoteness of the impacted area. Additionally, the magnitude of the spill may quickly overwhelm the deployed equipment necessitating the consideration of other techniques in the overall response strategy (The Science, Technology, and Effects of Controlled Burning of Oil Spills at Sea, Marine Spill Response Corporation, Washington, DC, 1994; Proceedings of the In Situ Burning of Oil Spills Workshop. NIST. SP934. MMS. 1998, p. 31; Basics of Oil Spill Cleanup, Lewis Publishers, Washington, DC, 2001, p. 233). This paper brings together the current knowledge on in situ burning and is an effort to gain regulatory acceptance for this promising oil spill response tool.  相似文献   

6.
In situ burning is being utilized in the United States to remove oil from inland oil spills, usually when physical recovery is not feasible. Studies have found that habitats may recover from the effects of burning in less than a year under optimal conditions but recovery may take much longer. Policies authorizing the use of in situ burning across the US are very inconsistent. Some states use it routinely, but others do not allow it. Inland in situ burning can be a useful response tool and the federal government needs to issue more guidance to the states. Responders also need to collect more data on the environmental impacts of burning.  相似文献   

7.
Thermal decomposition kinetics of three palm oleic acid-based alkyds with different oil lengths and having different molecular weights were studied using TGA measurements under non-isothermal conditions. Activation energies were obtained from Kissinger and Ozawa, Flynn and Wall (OFW) methods and subsequently the pre-exponential factor, A, degradation rate constant, k, for all the alkyds were also determined. From kinetic analysis of the thermal decomposition using the OFW method, it was found that degradation of all the alkyds has taken place in more than two stages, corresponding to different mechanisms. As shown from Ozawa and Kissinger methods, the chemical composition of the alkyds influenced the thermal degradation; increasing the phthalic anhydride and glycerol, and decreasing the oleic acid increased the thermal stabilities of the alkyds.  相似文献   

8.
9.
10.
In situ burning of inland and upland habitats is an alternative oil spill cleanup technique that, when used appropriately, may be more environmentally acceptable than intrusive manual, mechanical, and chemical treatments. There have been few published reports documenting the environmental effects of in situ burning in inland and upland habitats. Thus, this study, sponsored by the American Petroleum Institute, used two approaches to increase the knowledge base and improve the appropriate use of in situ burning: (1) detailed review of published and unpublished in situ burn case histories for inland and upland spills; and (2) summaries of fire effects and other information from the literature on fire ecology and prescribed burning. Thirty-one case histories were summarized to identify the state of the practice concerning the reasons for burning, favorable conditions for burning, and evaluations of burn effects. The fire ecology and effects summaries included information from the extensive knowledge base surrounding wildfire and prescribed burning (without oil) as a natural resource management tool, as well as fire tolerance and burning considerations for dominant vegetation types of the United States. Results from these two approaches should improve the application of in situ burning for inland and upland spills.  相似文献   

11.
A soypolyol based on epoxidized soybean oil (ESO) was prepared in the presence of HBF4 and diethanolamine (DEA) was used as ring opener. A series of polyurethane rigid foam were prepared by mixing polyol with TDI using an isocyanate index of 1.1. The polyol used in this paper were a mixture of soypolyol and a commercial PL-5601 polyester polyol and the mass fraction of PL-5601 was in the range of 0–60%. The thermal properties of the resins were characterized by DSC and TG. The results showed that these rigid foams possess high thermal stability. There were two glass transition temperature of each foam and Tg1 was increasing with the increasing of OH value. The compression strength of the foam was also recorded, and the effect of mass ratio of soypolyol and PL-5601 polyester polyol on the compression strength was discussed.  相似文献   

12.
金劲松  杨毅 《化工环保》2011,(2):140-143
提出了水域泄漏油品回收技术的装备需求,介绍了水域泄漏油品问收处理措施.采用拦油栅来控制漂浮在水上的油品,将泄漏油品集中在相对较小的区域内,并使水面的浮油层加厚,然后使用人工或机械对泄漏油品进行回收.对于水域中的少量泄漏油品,采用吸油材料来进行吸附.在油膜较薄,难以用机械方法回收的情况下,使用消油剂或固化剂进行处理.水域...  相似文献   

13.
朱金安  陈云祥 《化工环保》2000,20(1):39-43,31
改进了用于水中硫化物测定的酸化-吹取-吸收预处理方法,对样样预处理条件及校准曲线的制作 进行了详细试验。该方法具有吹取完全,吸收安全、操作简单、准确度高的优点,适用于水和废水中微量硫化物的测定。  相似文献   

14.
15.
The aim of present study was to investigate the thermal properties and flame retardancy behavior of flame retardant (FR) epoxy nanocomposites from chemically treated (bromine water and tin chloride) oil palm empty fruit bunch (OPEFB) nano filler at different filler loading (1, 3, 5%). Thermal properties were evaluated through thermogravimetry analyzer, derivative thermogravimetry and differential scanning calorimetry. FR properties of nanocomposites are evaluated through UL-94 vertical burning test and limiting oxygen index (LOI). The functional group analysis of all composites was made by FTIR spectroscopy. Thermal analysis shows that degradation temperature of epoxy composites shifts from 370 to 410 °C and char yield also increases for 3% loading. Furthermore LOI value of 29% and UL-94 rating of V-0 with no flame dripping and cotton ignition, revealed that 3% oil palm nano filler filled epoxy nanocomposites display satisfactory flame retardancy. The superior flame retardancy of epoxy nanocomposites are attributed to the chemical reactions occurred in the gaseous phases and the profound synergistic flame retardation effect of tin with bromine in the treated nano OPEFB filler. All the epoxy nanocomposites displayed almost similar FTIR spectra with the characteristics metal-halogen bond supporting the synergism. Homogeneous dispersion of 3% oil palm nano filler act as highly effective combustion chain terminating agent compared with 1 and 5% nano OPEFB/epoxy nanocomposites.  相似文献   

16.
催化显色分光光度法测定水中银   总被引:2,自引:0,他引:2  
费世梅  郭伟英 《化工环保》1996,16(4):234-238
论述了目前测定水中银的常见方法,验证了银对亚铁氰化钾与邻菲罗啉反应的催化作用,建立了测定水中银的催化显色分光光度法。  相似文献   

17.
刘玲  齐敏  彭敬雪  商晓艳 《化工环保》2013,33(4):376-378
考察各物质在测定水中亚硫酸盐含量时产生的干扰。实验结果表明,亚硝酸、S2-、COO-均会对测定结果产生干扰,采用吹扫-酸化-水浴加热-吸收的预处理方法,可消除这些物质产生的干扰;本方法的适用范围为0~5mg/L(以SO32-),最低检出限为0.1mg/L;测定结果的相对标准偏差均在2%以内,加标回收率为98.1%~103.6%。  相似文献   

18.
Removal of toxic pollutants from water and wastewater is becoming an important process with the increase of industrial activities. The present study focused on assessing the suitability and efficiency of water bamboo leaves (WBL) for the removal of cationic dye from aqueous solutions. The effect of different variables in the batch method including solution pH (2–12), initial dye concentration (50–250 mg L?1), adsorbent dose (0.05–0.30 g), contact time (5–180 min) and temperature (283–333 K) on the dye removal was investigated. The adsorption kinetics was discussed in view of four kinetics models. The results showed that the pseudo-second-order kinetics model described dye adsorption on WBL very well. The experimental equilibrium data were also tested by four isotherm models. It was found that adsorption of dye on WBL fitted well with the Langmuir isotherm model, implying the binding energy on the whole surface of the adsorbent was uniform and the dye molecules onto the surface of the adsorbent were monolayer coverage. Calculation of various thermodynamic parameters of the adsorption process indicated feasibility and exothermic nature of dye adsorption.  相似文献   

19.
Epoxy resin prepared by the reaction of a diglycidyl ether of bisphenol A (DGEBA) and m-xylylenediamine (m-XDA) was modified with 10% wt of epoxidized palm oil (EPO). The EPO was first pre-polymerized with m-XDA at various temperatures and reaction times. The resulting product was then mixed with the epoxy resin at 40?°C and allowed to react at 120?°C for another 3?h. The fully reacted DGEBA/m-XDA/EPO blend was characterized by using scanning electron microscopy (SEM), differential scanning calorimetry (DSC), thermal gravimetric analysis, tensile test, hardness indentation and dynamic mechanical analysis. The SEM study shows that different types of morphology, ranging from phase separated to miscible blends were obtained. A miscible blend was obtained when the m-XDA and EPO were reacted for more than 2?h. The results from DSC analysis show that the incorporation of EPO at 10% wt in the epoxy blend reduced the glass transition temperature (T g). The lowered T g and mechanical properties of the modified epoxy resins are caused by a reduction in crosslinking density and plasticizer effect.  相似文献   

20.
流动注射分光光度法测定水中痕量氟化物   总被引:8,自引:0,他引:8  
吴宏  徐丽娜  王镇浦 《化工环保》1999,19(6):369-372
研究并建立了测定水中痕量氟化物的氟试剂(ALC)-流动注射分光光度法。将水样注入到水载流中,与ALC-La丙酮水溶液混合,在50℃时反应生成蓝色三元络合物,在分光光度计上于波长618mm处进行检测。F^-测定的线性范围为0.04-3.0mg/L,检出限为0.036mg/L。  相似文献   

设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号