Modeling the fate of oil spills at sea

A numerical model for the simulation of the physicochemical weathering processes of an oil spill at sea is presented based on state-of-the-art models. The model includes the most significant processes: spreading, evaporation, dispersion into the water column, emulsification and the change in viscosity and density. These processes depend on each other and are allowed to vary simultaneously since processes are described by a set of differential equations, solved by a fourth-order Runge-Kutta method. Numerical examples are given, in order to test the results obtained, and compared with available experimental data in the literature. The model predicts well the variation of water incorporation, density and viscosity but seems to overestimate the fraction evaporated. However more experimental data are needed to calibrate and validate the model since differences in the composition of the simulated oil and the samples from which experimental data are taken may occur in evaporation studies. The model is suitable to join other modules for the prediction of the spill trajectory by advection due to winds and currents and sub-sea transport.     

Comparative occurrence rates for offshore oil spills

Estimates of occurrence rates for offshore oil spills are useful for analysis of potential oil spill impacts and for oil spill response contingency planning. As the Oil Pollution Act of 1990 (U.S. Public Law 101–380, 18 August 1990) becomes fully implemented, estimates of oil spill occurrence will become even more important to natural resource trustees and to responsible parties involved in oil and gas activities. Oil spill occurrence rate estimates have been revised based on U.S. Outer Continental Shelf platform and pipeline spill data (1964–1992) and worldwide tanker spill data (1974–1992). These spill rates are expressed and normalized in terms of number of spills per volume of crude oil handled. The revisions indicate that estimates for the platform spill occurrence rates declined, the pipeline spill occurrence rates increased, and the worldwide tanker spill occurrence rates remained unchanged. Calculated for the first time were estimates of tanker and barge spill rates for spills occuring in U.S. waters, and spill occurrence rates for spills of North Slope crude oil transported by tanker from Valdez, Alaska. All estimates of spill occurrence rates were restricted to spills greater than or equal to 159 m³ (1000 barrels).     

The evaporation of oil spills: Prediction of equations using distillation data

This work follows on extensive empirical studies on the evaporation of oil and petroleum products. A study of the evaporative characteristics of 19 different crude oils and petroleum products was conducted. Best-fit equation parameters were determined for both percentage loss by time and absolute weight loss. All oils except for three (diesel fuel, FCC Heavy Cycle and Bunker C light) were found to fit logarithmic curves. The exceptions noted, fit square root curves with time for periods up to about 5 d. The equation constants were correlated with oil distillation data. The equation constants correlated highly with the percentage distilled at 180°C. Using this correlation, equations were developed by which the oil evaporation can be predicted using the distillation data alone.     

An approach to evaluate the application of the vulnerability index for oil spills in tropical Red Sea environments

The Egyptian national marine oil pollution contingency plan was urgently initiated after the Nabila oil spill in 1982, to provide an estimate of its environmental effects on the Egyptian Red Sea coastal areas and to determine geomorphological features and cuastal processes, together with physical, chemical and biological baseline data for this tropical environment.The ‘Vulnerability Index’ (VI) was applied to evaluate and calibrate the effect of the Nabila oil spill on the Egyptian Red Sea Coastal area. A detailed in situ coastal survey was conducted during two visits in November 1982 and May 1983 to 80 shore sites from Suez to Ras Banas to monitor the oil pollution and to apply the ‘Vulnerability Index’. A comparative assessment of the index over time by comparing it with a quick ground inspection in November 1993 to some sites to evaluate the applicability of this index for oil spills in such environments. In addition, the physical effects of fresh and weathered crude oil and/with dispersant on water filtration by different beaches were preliminary studied.The geomorphological/Vulnerability Index results show that most of the Egyptian Red Sea coastal environments have medium to high vulnerability to immediate and medium term oil spill damage. The oil pollution spread estimated to be 250 km south of the oil spill and about 200 km north of it. The quantity of oil along the shoreline was reduced by about 60% due to natural and authorities clean up. The third survey after 11 years showed that the VI could be used as a predictive tool for assessment of oil spill effects on such tropical environments.     

餐厨废弃油脂全程管理实现途径研究

餐饮服务、食品生产及食品加工等环节产生的餐厨废弃油脂,其管理工作事关民生大计,紧系食品安全、生态环境和公众身体健康.为确保餐厨废弃油脂从源头到收运和处置流向的全程控制管理,结合上海实际,对餐厨废弃油脂全程管理的实现途径进行了研究和探讨.     

Determination of the best appropriate management methods for the health-care wastes in Istanbul

Health-care waste management has been a significant problem in most economically developing countries as it is in Turkey. Most of the time, the main reason for the mismanagement of these wastes is the lack of appropriate legislation and effective control; other reasons are: financial strains and a lack of awareness. Being aware of the significance of the subject, in this paper the management of the health-care wastes in Istanbul, as a Metropolitan City of Turkey, was analyzed to create an integrated health-care waste management system in the city. Within the scope of the study, the existing situation and management practices such as the amount of the health-care wastes generated, segregation procedures, collection, temporary storage and transportation of the wastes within and outside of the institution were examined. Deficiencies, inconsistencies and improper applications were revealed. The existing Turkish Medical Wastes Control Regulation and institutional structure of the health-care waste management body were reviewed. After the evaluation and comparison with the requirements of other national and international organizations, items to be changed/added in the Regulation were identified. At the end of the study, the best management methods for the Istanbul City were determined and started to be applied at the institutions. After this study, the existing Regulation has been changed. The modified Regulation was published in 2005 and implementation has started. It is expected that by the application and implementation of the research outcomes, the management of health-care wastes in Istanbul and then in all over Turkey will be improved. The results obtained can also be used in most economically developing countries where there are similar environmental problems and strict budgets.     

Review and meta-analysis of 82 studies on end-of-life management methods for source separated organics

This article reports on a literature review and meta-analysis of 82 studies, mostly life cycle assessments (LCAs), which quantified end-of-life (EOL) management options for organic waste. These studies were reviewed to determine the environmental preferability, or lack thereof, for a number of EOL management methods such as aerobic composting (AC), anaerobic digestion (AD), gasification, combustion, incineration with energy recovery (often denoted as waste-to-energy incineration), mechanical biological treatment, incineration without energy recovery (sometimes referenced by just the word “incineration”), and landfill disposal with and without energy recovery from generated methane. Given the vast differences in boundaries as well as uncertainty and variability in results, the LCAs among the 82 studies provided enough data and results to make conclusions regarding just four EOL management methods – aerobic composting, anaerobic digestion, mass burn waste-to-energy (WTE), and landfill gas-to-energy (LFGTE). For these four, the LCAs proved sufficient to determine that aerobic composting and anaerobic digestion are both environmentally preferable to either WTE or LFGTE in terms of climate change impacts.For climate change, LCA results were mixed for WTE versus LFGTE. Furthermore, there is a lack of empirically reliable estimates of the amount of organics input to AD that is converted to energy output versus remaining in the digestate. This digestate can be processed through aerobic composting into a compost product similar to the compost output from aerobic composting, assuming that the same type of organic materials are managed under AD as are managed via AC. The magnitude of any trade-off between generation of energy and production of compost in an AD system appears to be critical for ranking AC and AD for differing types of organics diversion streams. These results emphasize how little we generally know, and exemplify the fact that in the reviewed literature no single EOL management method consistently topped all other management options across all environmental impacts, and that future studies must strive to match existing analytical boundaries and alternatives assessed to increase knowledge if as a community we expect to be able to make even more generalized conclusions.     

餐厨废弃油脂处理管理和资源化利用探讨

“地沟油”的不当处理不仅影响城市水环境,而且威胁着人们的身体健康。餐厨废弃油脂的管理已经成为广受关注的食品安全的重大问题。介绍了餐厨废弃油脂处理管理的重要意义,并对上海的管理实践和经验进行了分析总结,提出了对餐厨废弃油脂回收处理管理和资源化利用的若干建议。     

Environmental and economic assessment methods for waste management decision-support: possibilities and limitations.

A large number of methods and approaches that can be used for supporting waste management decisions at different levels in society have been developed. In this paper an overview of methods is provided and preliminary guidelines for the choice of methods are presented. The methods introduced include: Environmental Impact Assessment, Strategic Environmental Assessment, Life Cycle Assessment, Cost-Benefit Analysis, Cost-effectiveness Analysis, Life-cycle Costing, Risk Assessment, Material Flow Accounting, Substance Flow Analysis, Energy Analysis, Exergy Analysis, Entropy Analysis, Environmental Management Systems, and Environmental Auditing. The characteristics used are the types of impacts included, the objects under study and whether the method is procedural or analytical. The different methods can be described as systems analysis methods. Waste management systems thinking is receiving increasing attention. This is, for example, evidenced by the suggested thematic strategy on waste by the European Commission where life-cycle analysis and life-cycle thinking get prominent positions. Indeed, life-cycle analyses have been shown to provide policy-relevant and consistent results. However, it is also clear that the studies will always be open to criticism since they are simplifications of reality and include uncertainties. This is something all systems analysis methods have in common. Assumptions can be challenged and it may be difficult to generalize from case studies to policies. This suggests that if decisions are going to be made, they are likely to be made on a less than perfect basis.     

Evaluation of environmental pollution and possible management options of heavy oil fly ash

Due to the presence of toxic metals, dumping of heavy oil fly ash (HOFA) is causing ever-growing environmental problem including the pollution of air, water and soil. The present study investigates the possible environmental impacts associated with the land disposal of HOFA generated in the power plant. Different modeling and laboratory analysis were integrated to address the real environmental problems. Leaching behavior of heavy metals within the HOFA were investigated by laboratory batch leaching tests, which confirmed that most of the toxic elements in the HOFA can easily leach into the environment with rain water. The level of atmospheric dust surrounding a HOFA dumping site was predicted using the Industrial Source Complex (ISC3) air dispersion model, and the results indicated that the dumping of HOFA could be a potential hazard for local air quality. The study also revealed different reuse options of HOFA. The characteristic analysis confirmed HOFA can be used as a natural adsorbent to remove pollutants from wastewater or as soil stabilizing material by blending with cement.     

A study on the effects of oil fires on fire booms employed during the in situ burning of oil

For over 10 years scientists have studied the effects of in situ burning of oil on air and water quality and potential related health issues. The recent Newfoundland Offshore Burn experiment, conducted by Environment Canada, was the culmination of several years of work. The results of this experiment found that ‘emissions from the in situ oil fire were lower than expected and all compounds and parameters measured were below health concerns at 150 m from the fire’ (The Newfoundland Offshore Burn Experiment—NOBE, Preliminary Results of Emissions Measurement). Polyaromatic Hydrocarbons (PAHs) were found to be lower in the soot generated from the fire than in the starting oil prior to the fire. The conclusion reached was that the environmental benefits resulting from the burning of oil spills far outweigh the potential air pollution caused from the smoke. These findings now open the door on the use of in situ burning of oil as a major tool to be used to mitigate environmental damage from oil spills.As a result of these and other test findings, Region 6 of the Regional Response Team (made up of the U.S. Coast Guard, The Minerals Management Service, The Department of Environmental Quality, The U.S. Environmental Protection Agency, and other state and federal agencies) had pre-approved the use of in situ burning of oil spills for offshore Louisiana and Texas. Other parts of the country and other countries are evaluating the use of in situ burning to combat oil spills. Now that the scientific community has weighed the environmental costs and benefits of in situ burning it is time to address the operational and procedural issues.     

Microwave radiometer system for the detection of oil slicks

A major problem of radiometric sensors in the detection of oil spills on the sea is differentiating the oil spill from other objects on the water surface such as rough areas, areas with warm and cold streams, oil-water emulsions, areas with seaweed, etc. A procedure to convert antenna temperatures to brightness temperatures and then to the oil thickness is described. Generally, a calibration procedure at the start of each experiment is needed. In order to develop and test these procedures, a polarization method has been designed for remotely detecting an oil slick. This required building three radiometers operating in the millimeter-wave bands (W, W_a, k_u) as well as associated laboratory test equipment. Experimental results, obtained in the laboratory and in an outdoor test facility, conform well with theoretical computations using an air-oil-water stratified layer model. This new method of microwave radiometry by measuring its polarization contrasts at two orthogonal polarizations is a next step in the development of microwave sensors for detecting oil spills.     

废弃电器电子产品处理基金补贴中数量审核方法的探讨

简要介绍了废弃电器电子产品概况、相关法律法规以及基金补贴过程中审核产品数量的现实做法,指出了现有审核机制中存在的一些问题,并根据废弃电器电子产品资源化过程中对主要污染产物的重点监控,提出一种多级比对的处理数量审核方法。     

油页岩灰渣浸取铝酸钠溶液试验研究

以油页岩废渣为原料,通过酸浸法浸取油页岩灰渣中的铝酸钠溶液.采用焙烧活化方法将废渣中含铝的低活性晶体物质活化为高活性半晶体或非晶体物质,利用酸浸法浸取焙烧后的高活性含铝废渣,得到铝液;依据试验分析了影响酸浸法浸取铝酸钠溶液的主要影响因紊为焐烧温度、焙烧时间、浸取酸浓度和浸取温度;得出酸浸法的最佳工艺参教:活化温度850℃,活化时间3 h,选用酸浓度40%,浸取温度60℃,此时油页岩废渣铝浸取率为75%.     

英国废弃烹调油再生利用现状分析

以英国废弃烹调油的回收、处理和再生利用的产品为主线,结合与其相关的政策、法规及有效激励方法在废弃烹调油再生利用管理过程中的作用,详细介绍了英国废弃烹调油再生利用的管理现状,以期对我国废弃烹调油及其他废弃物的循环经济实践提供具体的参考案例。     

Test methods for assessing the biological stability of biodegradable waste

This paper presents some results of investigations for the characterization of waste excavated from closed landfills and of waste sampled during mechanical-biological pretreatment before disposal in landfill. The results reported are those obtained with the tests carried out for the assessment of the biological stability of the waste. Some of the considered tests, such as the ones for the determination of the respiration activity and the biogas production, are well known and have been applied for years; other tests, such as the ones for the determination of BOD5 and COD in leaching test eluate and of the black index, are among the tests considered by the international research community for possible utilization for the evaluation of waste biological stability. Good correlations were found for most of the results obtained, proving the reliability of the test methods used. In particular, the effectiveness of biodegradation during waste pretreatment processes can be easily monitored by measuring the respiration index and/or the BOD5 and COD in leaching test eluate; for the characterization of waste from landfills, the use of respiration index can be recommended. In both cases the COD in leaching test eluate may provide additional useful information especially in the case of low values for the respiration index. Moreover, the black index test may be considered with some limits that will be discussed, providing good results in a simple and cost effective way.