连续管钻塞水平段铁屑运移机理研究

针对水平井段连续管钻磨桥塞时铁屑运移规律尚认识不清,沉积的铁屑堆积在井下工具周围而导致卡钻的问题,在欧拉坐标系下考虑相间滑移速度以及铁屑流参数,建立了三维井眼环空铁屑运移模型,采用Standard κ－ε湍流模型及SIMPLEC算法进行数值计算,研究了环空偏心度、钻塞液排量、铁屑直径、钻塞液粘度和铁屑体积分数对水平段铁屑运移的影响,得到了环空铁屑体积分数和固定铁屑床高度的分布规律。研究表明:增大钻塞液排量、减小铁屑直径、减小环空偏心度、增大钻塞液粘度和减小铁屑体积分数,可提高连续管钻塞水平段铁屑运移效率。水平段铁屑运移机理研究可为连续管钻磨桥塞卡钻问题的解决提供技术支持。     

Human hair as a potential biomonitor for assessing persistent organic pollutants

To explore human biomonitor of persistent organic pollutants (POP) for public health risk assessment, extractable organohalogens (EOX), extractable persistent organohalogens (EPOX) and some selected organochlorine pesticides (OCP) and polychlorinated biphenyls (PCB) in children hair from urban and rural regions of Beijing, China, were measured by instrumental neutron activation analysis (INAA) and gas chromatography-electron capture detector (GC-ECD). The results indicated that about 96% of the total halogens existed as water-soluble polar compounds; about 25 to 50% of EOX were sulfuric acid-resistant EPOX; organochlorines were the major fraction of the organohalogens; and 88 to 99.6% of extractable persistent organochlorines (EPOCl) cannot be attributed to the selected OCP and PCB. HCH, DDT and 2-5CB were the major contributors to hair OCP and PCB. Further, gamma-HCH, p,p'-DDE, p,p'-DDT and PCB-52 were the predominant individuals of HCH, DDT and 2-5CB, respectively. The concentration distributions of EPOCl, HCH, DDT and PCB in children hair were generally in the order of urban>rural and girls>boys, except for PCB congeners with random distributions between genders. Pearson positive correlations between hair lipid and the detected parameters of hair gamma-HCH (p<0.01), DDT (p<0.01), EOCl (p<0.05), as well as EPOCl (p<0.05) were observed. Also, the ratios of hair alpha/gamma and p,p'-DDE/p,p'-DDT suggested that fresh input of HCH and DDT might exist in Beijing area. Hair can reflect body's integral exposure to POP from endogenous and exogenous sources, which, thus, can be used as a potential biomonitor in assessing POP exposure for public health purposes.     

九顶山西坡汶川段维管植物区系研究

汶川是"五·一二"特大地震的中心地带,也是受灾最为严重的区域.本文基于震前3 a的实地调查资料,对龙门山脉主峰--九顶山西坡汶川段的植物区系进行了系统分析,以期为灾后生物多样性的监测评估提供依据.在对九顶山西坡汶川雁门沟的野外调查中共发现维管植物111科、363属、733种,其中有种子植物94科、333属、687种.科的物种丰富性很高,含10种以上的种子植物科有19个,含216属、455种植物,分别占该区维管植物总属数和总种数的59.50%和62.07%,是该区植物区系构成的主导成分.种子植物区系成分复杂,15种分布类型在该区均有分布;温带分布的属和种远远超过热带分布类型,体现了该植物区系明显的温带性质.在东亚分布类型中,属于中国-喜马拉雅类型的属和种所占比例远远高于中国-日本成分,说明九顶山虽处于中国-喜马拉雅森林植物亚区与中国-日本森林植物亚区的交界线附近,但其西坡汶川段依然属于中国-喜马拉雅森林植物亚区的范畴.有367个中国特有种分布于该区,占物种总数的53.42%,其中半数以上的物种属于中国西南特有种或横断山区特有种,进一步证明中国西南高山区特别是横断山地区是温带植物物种的分化中心这一事实.图1表5参11     

烟气脱硫石膏和园林废弃物堆肥混合施用对滨海盐渍土壤的改良

为克服烟气脱硫石膏改良盐碱地存在的土壤盐分升高、营养物质降低等不足,通过对不同重量配比的园林废弃物堆肥与适量烟气脱硫石膏混合施用,且开展了其对上海南汇滨海盐渍土的改良效应研究。结果表明:2种改良剂混合施用能显著降低滨海盐渍土pH和全盐含量,增加土壤营养物质含量和植物生物量,并提高植物对营养物质的吸收能力;与对照相比,当烟气脱硫石膏施用量为25 g·kg~(-1)时,土壤pH降低了10.9%,EC升高了8.4%,有效磷、有效氮和速效钾含量分别降低了30.1%、 40.5%和36.1%,黑麦草发芽率下降了8.0%,植株内全氮、全钾含量均有所升高,但全磷含量减少了25.4%;混合施加不同重量配比的园林废弃物堆肥后,土壤pH降幅为6.8%～13.8%, EC降幅为4.2%～11.6%;土壤有效磷、有效氮和速效钾含量增幅分别为96.0%～182.7%、40.0%～186.7%和71.7%～157.5%;黑麦草发芽率和生物量逐渐增加,在园林废弃物堆肥施用量为40%时,与对照处理相比,此时植物发芽率达到90.0%,总湿重、地上干重、株高和根长等分别增加了154.1%、100.0%、89.2%和103.6%,植株体内氮和钾含量分别增加了139.9%和40.8%,磷的含量则接近对照处理。通过分析可知,烟气脱硫石膏和园林废弃物混合施用可较好地改良滨海盐渍土壤,并为城市固废的适合处置方式和综合利用途径提供了参考。     

石油加工过程的环境影响后评价

我国的石油加工过程环境影响评价工作属于前期预测评价,存在一定的局限性。目前,石油加工过程的环境影响后评价工作尚处于探索发展阶段。本文主要介绍了石油加工过程及其环境影响后评价的概念,分析了石油加工过程的主要环境影响,详述了石油加工过程环境影响后评价的程序、内容及评价指标,并结合实例加以说明。最后指出,开展石油加工过程的环境影响后评价工作势在必行。     

Application of a novel cold activated carbon fiber-solid phase microextraction for analysis of organochlorine pesticides in soil

A novel and simple analytical procedure using cold activated carbon fiber-solid phase microextraction (CACF-SPME) was applied to determine organochlorine pesticides (OCs) in soil samples. The pesticides in this study consist of α -, β -, γ -, and δ -hexachlorocyclohexane (HCH). By heating the sample while cooling the fiber, the developed method not only provides better performance in terms of sensitivity, linearity and recovery but also offers shorter adsorption procedure than that of traditional headspace-solid phase microextraction (HS-SPME). The experimental conditions such as the amount of water, adsorption time and adsorption temperature were optimized. Matrix effects were investigated with different types of soils. We concluded that using the standard addition method was required for quantification purposes. The limits of detection obtained using the proposed method range from 0.01 to 0.05 ng/g, and the recoveries for CACF-SPME are in the range of 80.01% to 89.68% with relative standard deviation (RSDs) better than 8.60%. The proposed method was further applied to determine OCs in real agricultural soil. The results are in good agreement with those obtained using traditional ultrasonic extraction. The research demonstrates the suitability of the CACF-SPME for the analysis of OCs in soil.     

运城市水污染控制与污水资源化对策

水环境污染与水资源紧缺是制约运城市建设与发展的两大重要因素。分析了运城市水污染现状与特征,提出了通过调整产业结构与布局、建立与完善地方法规和政策支持体系、加强综合协调与监督管理、加大科技投入及完善市场化运行机制等手段和措施防治与控制运城市水污染,实现污水资源化。     

不透水表面雨水径流污染物冲刷规律研究

针对雨水径流污染冲刷模型中降雨强度与污染物冲刷存在的时间差问题,采用有效降雨强度替代降雨强度,建立了径流污染物冲刷模型,并利用建立的模型对不透水表面雨水径流污染物冲刷进行了模拟。结果表明,模型对SS、COD、TN和TP模拟的相关系数R2平均为0.87、0.81、0.93和0.89,具有较高的模拟精度。SS、COD、TN和TP的冲刷系数分别为0.77、0.66、0.92和0.74 mm-1,TN的冲刷系数略高,但总体相差不大。SS、COD、TN和TP均显示了较强的初期冲刷效应,在有效降雨强度为4 mm时,截留初期雨水径流量的35%~40%,即可控制70%以上雨水径流污染物。建立的模型可应用于研究不透水表面的雨水径流污染物冲刷规律,为雨水径流污染物控制提供理论计算依据。     

Air Quality Impact of the Coal-Fired Power Plants in the Northern Passageway of the China West-East Power Transmission Project

Abstract

This paper analyzes the air quality impacts of coal-fired power plants in the northern passageway of the West-East Power Transmission Project in China. A three-layer Lagrangian model called ATMOS, was used to simulate the spatial distribution of incremental sulfur dioxide (SO₂) and coarse particulate matter (PM₁₀) concentrations under different emission control scenarios. In the year 2005, the emissions from planned power plants mainly affected the air quality of Shanxi, Shaanxi, the common boundary of Inner Mongolia and Shanxi, and the area around the boundary between Inner Mongolia and Ningxia. In these areas, the annually averaged incremental SO₂ and PM₁₀ concentrations exceed 2 and 2.5 µg/m3, respectively. The maximum increases of the annually averaged SO₂ and PM₁₀ concentrations are 8.3 and 7.2 µg/m³, respectively, which occur around Hancheng city, near the boundary of the Shaanxi and Shanxi provinces. After integrated control measures are considered, the maximum increases of annually averaged SO₂ and PM₁₀ concentrations fall to 4.9 and 4 µg/m³, respectively. In the year 2010, the areas affected by planned power plants are mainly North Shaanxi, North Ningxia, and Northwest Shanxi. The maximum increases of the annually averaged SO₂ and PM₁₀ concentrations are, respectively, 6.3 and 5.6 µg/m³, occurring in Northwest Shanxi, which decline to 4.4 and 4.1 µg/m³ after the control measures are implemented. The results showed that the proposed power plants mainly affect the air quality of the region where the power plants are built, with little impact on East China where the electricity will be used. The influences of planned power plants on air quality will be decreased greatly by implementing integrated control measures.