采油废水的深度处理回用

采用溶气气浮—生物接触氧化—膜分离组合工艺深度处理采油废水。实验结果表明,出水水质满足热采锅炉进水要求。该法可年处理废水1.3×105m3,产水率按50%计,年节约新鲜水和废水回灌费用共计77.88万元,年节水效益为21.71万元。     

Microbial reduction of uranium (VI) by Bacillus sp. dwc-2: A macroscopic and spectroscopic study

The microbial reduction of U(VI) by Bacillus sp. dwc-2, isolated from soil in Southwest China, was explored using transmission electron microscopy (TEM), X-ray photoelectron spectroscopy (XPS) and X-ray absorption near edge spectroscopy (XANES). Our studies indicated that approximately 16.0% of U(VI) at an initial concentration of 100 mg/L uranium nitrate could be reduced by Bacillus sp. dwc-2 at pH 8.2 under anaerobic conditions at room temperature. Additionally, natural organic matter (NOM) played an important role in enhancing the bioreduction of U(VI) by Bacillus sp. dwc-2. XPS results demonstrated that the uranium presented mixed valence states (U(VI) and U(IV)) after bioreduction, which was subsequently confirmed by XANES. Furthermore, the TEM and high resolution transmission electron microscopy (HRTEM) analysis suggested that the reduced uranium was bioaccumulated mainly within the cell and as a crystalline structure on the cell wall. These observations implied that the reduction of uranium may have a significant effect on its fate in the soil environment in which these bacterial strains occur.     

聚苯乙烯/CdS/TiO_2双壳层核壳纳米颗粒可见光催化降解甲基橙

采用溶胶-凝胶法,在聚苯乙烯(PS)/CdS核壳纳米颗粒表面包覆致密TiO_2层,制备出具有双壳层结构的PS/CdS/TiO_2纳米复合颗粒,考察了制备条件对材料结构的影响,并利用甲基橙溶液对其光催化性能进行了评价。SEM、TEM、XRD和FTIR分析结果表明,制得的微球单分散性良好,壳层包覆完整,厚度均匀。PS/CdS/TiO_2制备的适宜反应时间为12~18 h,适宜反应pH为7~9。PS/CdS/TiO_2较PS/CdS具有更为优异的可见光催化性能。     

便携式GC-MS在石油污染土壤应急监测中的应用

针对石油污染土壤中VOCs含量的应急监测,便携式气相色谱-质谱联用仪适用于土壤中甲苯、乙苯、二甲苯、三氯苯等13种苯系物的快速定量检测,通过对某废弃炼油厂土壤样品测定,该方法在快速定性的同时,定量测定5~20411μg/kg土壤样品具有很高的可靠性。     

风雨联合作用下风向对大跨度悬挑屋盖的压力分布影响研究

强降雨通常伴有强风作用,风向成为影响结构表面压力分布的重要因素之一。目前大跨度挑檐屋盖设计基本只考虑垂直于结构表面的单独雨荷载作用,对风雨联合作用下建筑表面压力分布研究甚少。研究风雨联合作用下,不同风向对大跨度悬挑屋盖表面的压力分布影响特性。基于数值模拟平台,采用欧拉-欧拉方法,模拟得到了不同风向工况下大跨度悬挑屋盖结构表面平均压力分布规律,并研究得到了一次自然降雨过程中最不利抗风雨位置,对相应大跨度悬挑结构设计提出了有益参考。     

有机污染物在水体表面微层的富集行为

研究邻苯二甲酸二丁酯（ＤＢＰ）,邻苯二甲酸二异辛酯（ＤＥＨＰ）和阴离子表面活性剂在水体表面微层的富集行为．现场分析结果表明邻苯二甲酸酯在小型封闭湖泊表面微层中存在富集现象,富集倍数在１～１１之间,湖水的理化性质及采样方式均影响富集倍数的大小．室内微宇宙研究表明ＤＢＰ和ＤＥＨＰ在微宇宙水体表面微层中均存在富集现象,富集倍数分别为２．８１和１．９８,藻类、颗粒物和腐殖酸也同时在微宇宙水体表面微层中富集．当水体中加入表面活性物质和腐殖酸时,邻苯二甲酸酯（ＤＢＰ、ＤＥＨＰ）在表面微层的富集倍数随加入的２种物质浓度的增大而降低．对阴离子表面活性剂的富集动力学研究表明,当表面微层遭到破坏后,其在表面微层达富集平衡需较长时间,水体浓度也影响富集倍数     

粉末活性炭对三烯丙基异氰脲酸酯的吸附性能简

用静态吸附法考察粉末活性炭对水中三烯丙基异氰脲酸酯（CAIC）的吸附行为,采用单因素分析法对活性炭吸附化工废水中TAIC的工艺条件进行研究。实验结果表明,在TAIC模拟废水中,其TAIC初始浓度为800 mg/L,pH为7,在温度为298 K、转速为150 r/min的条件下,当活性炭的投加量达到4.4 g/L,吸附反应时间为50 min时,TAIC的去除效率最高为96.17%;对于实际废水,其TAIC初始浓度为1 500 mg/L,溶液pH为3,在温度为298 K、转速为150 r/min的条件下,当活性炭投加量达到10 g/L,吸附反应时间为2 h时,TAIC的去除效率最高为46.8%。这也是由于实际废水组分复杂,其他有机物存在一定的吸附竞争机制。     

TiO2-Cu2O/蒙脱土复合光催化剂的制备与性能

以钠基蒙脱土（MMT）为载体,先采用溶胶-凝胶法将纳米TiO₂引入到MMT层间,再采用化学沉积法将纳米Cu₂O负载在TiO₂/MMT上,制备出TiO₂-Cu₂O/MMT纳米复合光催化剂。采用XRD、SEM、紫外-可见漫反射技术对催化剂进行了表征。以甲基橙为目标污染物,考察了催化剂的光催化性能。表征结果显示：TiO₂与Cu₂O均匀分布在MMT的表面与片层孔隙中;TiO₂-Cu₂O/MMT结合了TiO₂和Cu₂O的特性,拓宽了催化剂的光吸收范围。实验结果表明,在光源为可见光、初始甲基橙质量浓度为20 mg/L、光催化剂加入量为2 g/L的条件下,TiO₂-Cu₂O/MMT纳米复合光催化剂对甲基橙的光催化降解效果明显优于单一负载的Cu₂O/MMT和TiO₂/MMT,大幅提高了催化剂的光催化效率,反应300 min时TiO₂-Cu₂O/MMT对甲基橙溶液的脱色率达到93%。     

基于NORTA相关随机数的岩质边坡可靠性仿真评估

随机因素的合理表征是边坡可靠性评估的关键。NORTA方法是一种利用多维正态随机向量变换实现具有任意分布类型和可行相关矩阵的多维随机数生成的快速算法。以秀茂坪岩质边坡稳定可靠性为例,采用NORTA方法生成具有指定概率信息（边缘分布和相关系数）的相关随机数,利用MC仿真估计典型工况下的岩坡失稳概率,并在这一过程中探讨NORTA-MCS方法的限制、仿真结果的随机性以及通过控制变异系数估算仿真样本个数的途径。结果表明：相比自然状态下的秀茂坪岩坡,忽略相关性的岩坡失稳概率增加显著;而且随着粘聚力和内摩擦角间以及张力裂缝深度和充水程度间相关系数代数值的增大,秀茂坪岩坡的失稳概率也逐渐增大。     

An approach to the fluctuation mechanism of ecotone

In this paper,the relationship among land productivity,population pressure and the fluctuation mechanism of ecotone is analyzed,taking coumties and banners of southeast Inner Mongolia plateau as an example,which is the most fragile part in the farming and husbandry interleaving belt of north China due to its severe desertification degree and low level of economic development.The Cv for the total output value of agriculture decreases from southeast to northwest,with the same rule as which the overloading population cumulated distributes,and both indicators have close relation with the high linear coefficient of 0.83.These reveal the fluctuation mechanism for ecotone:fluctuation of the level of economic development is a scientific and practical measure both to weakness degree and to instability of ecotone,because it is a synthesized response to the variation of climate as well as irrational land uses,which reinforce and magnify the fluctuation.In detail,the heavier the population overloading,the severer the grassland reclamation,the stronger the dependence of regional productivity on rainfall,the lower the level of economic development,the rougher the fluctuation of ecotone,but the weaker the PRED system.