加油站油气回收系统VOCs泄漏FID现场检测方法及效果分析

油气回收系统密闭点VOCs泄漏质量分数值是衡量加油站是否存在超标排放的重要指标。为提高加油站VOCs泄漏检测的时效性、代表性与准确性,采用FID现场检测方法对郑州市某加油站油气回收系统进行了检测,全方位对比分析了实验室气相色谱法与现场检测法的检测时效性、准确性,提出了密闭区域检测及质量保证和控制建议,并根据实际检测数据分析了易泄漏点。结果表明：采用FID现场检测方法对油气回收系统密闭点进行检测,能使检测成本降低90%,检测效率提高 15 倍;在现场检测前完成仪器的校准、响应时间的测定与精密度的验证工作,可使VOCs最大质量分数偏差维持在5%以下,这进一步验证了FID现场检测方法测量的准确度;油气回收系统泄漏点的确定及现场检测流程和步骤的优化,可有效提高检测数据的代表性;检测设备的定期校准,可确保FID示值相对误差在±10％范围内,响应时间不超过30 s,从而为检测质量控制提供保障;为确保泄漏点完好,结合实际检测工作,应采用液位仪自动计量技术,加强设备的维护保养并设置加油枪气液比为1.05～1.15。综上所述,在保证FID的准确性与稳定性的前提下,采用FID现场检测方法对油气回收系统VOCs泄漏质量分数进行检测具有时效性强、准确度高、数据代表性强等优势。本研究结果可为加油站采用FID现场检测油气回收系统VOCs泄漏的质量分数提供参考。     

Evaluation of an ecosystem model in ecological risk assessment of chemicals

We used a Lake Suwa version of Comprehensive Aquatic Systems Model (CASM_SUWA) to demonstrate the risk estimation of 10 different chemicals and examined the applicability and reliability of the model in ecological risk assessment by qualitatively and quantitatively comparing with the results of studies on multiple species using mesocosm tests. The qualitative comparison of the model results with those of the reported mesocosm tests indicated that some evidence observed in mesocosm studies supported the indirect effects predicted from simulation using the model. The comparison of the concentration levels at which 20% biomass reduction (BR20) in the most sensitive population estimated from the model with the no-observed effect concentration values derived from multiple species mesocosm tests (MS-NOEC) suggested that both data were related to each other and the model can be used to help in the determination of an ecological acceptable level of chemicals in aquatic environments. The analysis of the potential of indirect effects of a chemical for fish population indicated that the magnitude of the potential of indirect effects was quantified based on the ratio of BR50 to LC50 for fish population.     

Optimization and assessment of an electrochemical advanced oxidation system for synthetic stormwater treatment

Environmental Science and Pollution Research - Electrochemical advanced oxidation processes (eAOPs) such as the current advanced oxidation system (AOS) are a type of electrochemical wastewater...     

Precipitation projection over Daqing River Basin (North China) considering the evolution of dependence structures

Environmental Science and Pollution Research - Understanding dynamic future changes in precipitation can provide prior information for nonpoint source pollution simulations under global warming....     

海洋石油工程新型溢油监测系统的研究

随着海洋石油的开采力度的加大,海上平台溢油事故也不断发生。在对传统监测方式的不足和海上溢油监测技术未来发展的趋势进行了综合考虑之后,开发了一套基于紫外诱导荧光探测技术的溢油监测系统。监测系统主要由检测终端、数据采集及异常报警系统和计算机处理及显示终端3个子模块组成,可以实现对海上平台潜在油污染源头信息的实时收集、传输、预警等功能。     

Investigating the fate of iodinated X-ray contrast media iohexol and diatrizoate during microbial degradation in an MBBR system treating urban wastewater

The capability of a moving bed biofilm reactor (MBBR) to remove the iodinated contrast media (ICM) iohexol (IOX) and diatrizoate (DTZ) from municipal wastewater was studied. A selected number of clones of microorganisms present in the biofilm were identified. Biotransformation products were tentatively identified and the toxicity of the treated effluent was assessed. Microbial samples were DNA-sequenced and subjected to phylogenetic analysis in order to confirm the identity of the microorganisms present and determine the microbial diversity. The analysis demonstrated that the wastewater was populated by a bacterial consortium related to different members of Proteobacteria, Firmicutes, and Nitrisporae. The optimum removal values of the ICM achieved were 79 % for IOX and 73 % for DTZ, whereas 13 biotransformation products for IOX and 14 for DTZ were identified. Their determination was performed using ultra-performance liquid chromatography–tandem mass spectrometry. The toxicity of the treated effluent tested to Daphnia magna showed no statistical difference compared to that without the addition of the two ICM. The MBBR was proven to be a technology able to remove a significant percentage of the two ICM from urban wastewater without the formation of toxic biodegradation products. A large number of biotransformation products was found to be formed. Even though the amount of clones sequenced in this study does not reveal the entire bacterial diversity present, it provides an indication of the predominating phylotypes inhabiting the study site.     

A first approximation kinetic model to predict methane generation from an oil sands tailings settling basin

A small fraction of the naphtha diluent used for oil sands processing escapes with tailings and supports methane (CH(4)) biogenesis in large anaerobic settling basins such as Mildred Lake Settling Basin (MLSB) in northern Alberta, Canada. Based on the rate of naphtha metabolism in tailings incubated in laboratory microcosms, a kinetic model comprising lag phase, rate of hydrocarbon metabolism and conversion to CH(4) was developed to predict CH(4) biogenesis and flux from MLSB. Zero- and first-order kinetic models, respectively predicted generation of 5.4 and 5.1 mmol CH(4) in naphtha-amended microcosms compared to 5.3 (+/-0.2) mmol CH(4) measured in microcosms during 46 weeks of incubation. These kinetic models also predicted well the CH(4) produced by tailings amended with either naphtha-range n-alkanes or BTEX compounds at concentrations similar to those expected in MLSB. Considering 25% of MLSB's 200 million m(3) tailings volume to be methanogenic, the zero- and first-order kinetic models applied over a wide range of naphtha concentrations (0.01-1.0 wt%) predicted production of 8.9-400 million l CH(4) day(-1) from MLSB, which exceeds the estimated production of 3-43 million l CH(4) day(-1). This discrepancy may result from heterogeneity and density of the tailings, presence of nutrients in the microcosms, and/or overestimation of the readily biodegradable fraction of the naphtha in MLSB tailings.     

A cumulative-risk assessment method based on an artificial neural network model for the water environment

Environmental Science and Pollution Research - To analyze the cumulative risks to the water environment, the backpropagation artificial neural network (BP-ANN), a self-adapting algorithm, was...     

Temporal ecological assessment of oil contaminated soils before and after bioremediation

Ecotoxicity methods were used to assess different soil and oil combinations before, during and after laboratory bioremediation with associated hydrocarbon analysis. Heavy, medium and light crude oil (API gravity 14, 30, and 55) was spiked (ca. 5% w/w) into two sandy soils in the laboratory having organic carbon concentrations of 0.3 (Norwood) and 4.7% (Norwood/Baccto). The earthworm (Eisenia fetida) 14-d lethality assay, the modified Microbics Microtox Solid-Phase assay, and the 14-d plant seed germination and growth assays using corn, wheat and oats, were spiked and tested during a 360-d laboratory remediation. Eisenia was the most sensitive of the three methods utilized with survival increasing throughout bioremediation with fastest toxicity reduction in the high carbon Norwood/Baccto soils where LC50's were 100% or greater at the end of 90-d whereas, > 150-d were required to achieve a similar result in the low carbon soil. Analysis of the undiluted treatments with oily soil alone showed that earthworm survival was high after 90-d in all high organic carbon soils, and after eight months in the low carbon soils, except for the Norwood soil-light oil treatment, which required 360-d to achieve 100% survival. The Microtox assay was less sensitive with EC50's 100% or greater observed after 90-d in high carbon soils and after 240-d for all low carbon soils. After bioremediation, no effects on seed germination were observed, although some plant growth inhibition effects remained. There was no direct correlation between total petroleum hydrocarbon concentrations and toxicity.     

垃圾填埋场渗漏电学监测系统设计及室内模拟试验

根据垃圾场渗滤液渗入地下后引起的地下介质电性变化及对自然电位场的改变,设计了用于垃圾填埋场渗滤液渗漏的在线电学监测系统。该系统在垃圾场建设期布设于高密度聚乙烯膜下方,在垃圾场运行期可实时监测垃圾场渗漏与否、渗漏点的位置及数量、渗滤液形成的羽状体在地下的形态,以便及时采取措施防止渗滤液造成严重的地下环境污染。并通过室内模拟实验证实了不同渗漏情况下,地下介质分布的电性剖面不同,电剖面异常区和污染区的分布具有空间对应关系。该系统的设置是实现环保型、智能型垃圾填埋场的重要举措。     

Numerical model of aerobic bioreactor landfill considering aerobic-anaerobic condition and bio-stable zone development

Environmental Science and Pollution Research - Aeration by airflow technology is a reliable method to accelerate waste biodegradation and stabilization and hence shorten the aftercare period of a...     

Molecular behavior assessment on initial stages of oil spill in terrestrial environments

Environmental Science and Pollution Research - The contamination of terrestrial environments by oil spills creates biological risks to humans and affects the ecosystem’s health. The studies...     

The land carrying capacity and environmental risk assessment of livestock and poultry breeding considering crop planting

Environmental Science and Pollution Research - At present, the contradiction between survival and ecology necessitates the integration of crop planting, chemical fertilizer application, and...     

Long-term assessment of particulate matter using CHIMERE model

Particulate matter (PM) and aerosols have became a critical pollutant and object of several research applications, due to their increasing levels, especially in urban areas, causing air pollution problems and thus effects on human health. The main purpose of this study is to perform a first long-term air quality assessment for Portugal, regarding aerosols and PM pollution. The CHIMERE chemistry-transport model, forced by the MM5 meteorological fields, was applied over Portugal for 2001 year, with 10 km horizontal resolution, using an emission inventory obtained from a spatial top-down disaggregation of the 2001 national inventory database. The evaluation model exercise shows a model trend to overestimate particulate pollution episodes (peaks) at urban sites, especially in winter season. This could be due to an underprediction of the winter model vertical mixing and also to an overestimation of PM emissions. Simulated inorganic components (ammonium and sulfate) and secondary organic aerosols (SOA) were compared to measurements taken at Aveiro (northwest coast of Portugal). An underestimation of the three components was verified. However, the model is able to predict their seasonal variation. Nevertheless, as a first approach, and despite the complex topography and coastal location of Portugal affected by sea salt natural aerosols emissions, the results obtained show that the model reproduces the PM levels, temporal evolution, and spatial patterns. The concentration maps reveal that the areas with high PM values are covered by the air quality monitoring network.     

石油炼化项目环境风险评价实例研究

结合某公司100万t/a延迟焦化项目的具体实例,探究石油炼化项目环境风险评价中的问题.利用故障树分析模型和ALOFT-FT模型,对延迟焦化项目生产装置和储存装置可能存在的环境风险进行半定量评价.结果表明,焦化装置中的焦化分馏炉和脱硫装置中的干气脱硫塔物料发生爆炸时,对人产生伤害的半径分别为157、199 m;液化石油气储存罐泄漏引发火灾,在下风向120 m,距地面60 m的范围内,黑色烟雾(VOC)日均值超过了0.3 mg/m3限值, 1 h平均值为1.35 mg/m3;而CO浓度相对较小.     

A dynamic model of optimal reduction of marine oil pollution

This paper proposes a system of dynamic models to describe the interactive behaviour of different agents (polluters, inspectors, and a principal pollution control agency) involved in the processes of marine oil pollution and of its prevention and purification, under some realistic assumptions. In particular, short- and long-term economic responses of polluters to monitoring efforts, as well as possible collusions between polluters and inspectors, are taken into account. A numerical example is considered using the results of Deissenberg et al., (2001a), which show the existence of optimal fines and inspector wage rates that minimise (along with other variables) a simple and visual 'social damage' criterion.     

1株好氧菌对不同油脂的降解

从某餐馆排污渠污泥分离到10株油脂降解菌,以植物油脂花生油为唯一碳源,通过适应性培养驯化并检测细菌生长的OD值筛选出1株优势菌。在确定其最佳生长环境条件的基础上,分别以花生油、餐厅污水和一种含有油脂的膜为对象污染物,进行了优势菌的降解试验。结果表明,该菌对花生油溶液中油脂和CODcr的去除率在24h以内分别达到98．91％和97．27％;对餐厅污染中油脂和CODcr的降解率在30h内分别达到88．66％和85．42％。另外,该优势菌对油脂膜也有良好降解效果,在固体和液体培养基中30d内油脂膜量分别减少了3．31％和11．29％以上。试验证实了该菌对植物油脂、含油脂污水和固体油脂废弃物有良好的净化效果。     

An environmental assessment model of construction and demolition waste based on system dynamics: a case study in Guangzhou

Environmental Science and Pollution Research - At present, China is in the rapid development stage of urbanization, and construction activities are becoming more frequent. This is accompanied by a...     

Loss of volatile hydrocarbons from an LNAPL oil source

The light nonaqueous phase liquid (LNAPL) oil pool in an aquifer that resulted from a pipeline spill near Bemidji, Minnesota, was analyzed for volatile hydrocarbons (VHCs) to determine if the composition of the oil remains constant over time. Oil samples were obtained from wells at five locations in the oil pool in an anaerobic part of the glacial outwash aquifer. Samples covering a 21-year period were analyzed for 25 VHCs. Compared to the composition of oil from the pipeline source, VHCs identified in oil from wells sampled in 2008 were 13 to 64% depleted. The magnitude of loss for the VHCs analyzed was toluene?o-xylene, benzene, C(6) and C(10-12)n-alkanes>C(7)-C(9)n-alkanes>m-xylene, cyclohexane, and 1- and 2-methylnaphthalene>1,2,4-trimethylbenzene and ethylbenzene. Other VHCs including p-xylene, 1,3,5- and 1,2,3-trimethylbenzenes, the tetramethylbenzenes, methyl- and ethyl-cyclohexane, and naphthalene were not depleted during the time of the study. Water-oil and air-water batch equilibration simulations indicate that volatilization and biodegradation is most important for the C(6)-C(9)n-alkanes and cyclohexanes; dissolution and biodegradation is important for most of the other hydrocarbons. Depletion of the hydrocarbons in the oil pool is controlled by: the lack of oxygen and nutrients, differing rates of recharge, and the spatial distribution of oil in the aquifer. The mass loss of these VHCs in the 5 wells is between 1.6 and 7.4% in 29years or an average annual loss of 0.06-0.26%/year. The present study shows that the composition of LNAPL changes over time and that these changes are spatially variable. This highlights the importance of characterizing the temporal and spatial variabilities of the source term in solute-transport models.