加油站油气回收效果检测及分析

对某地区4个加油站的油气回收改造效果进行了抽样检测。重点对一次油气回收中的回气量、回气浓度、回气压力和卸油速度以及二次油气回收中的密闭性、液阻和气液比等指标进行了测试,分析了存在的问题,并提出了相应的改造措施和建议。     

赤水河中下游冬季河水化学空间分布特征分析

通过在枯水期对赤水河中下游干流及其支流共25个河水样品进行水化学采样,水化学分析结果表明:在阴阳离子组成中,Ca2+为主要阳离子,占总阳离子的64%以上;阴离子以HCO3-和SO42-为主,占总阴离子75%~91%,其中HCO3-占51%以上。Gibbs图研究区河水化学组成受岩石风化作用控制,阴阳离子三角图、水化学比值分析表明研究区河水化学组成主要受碳酸盐岩风化作用影响,在下游部分支流存在一定硅酸盐岩风化作用。水化学时空分布的对比分析表明,人为活动的对赤水河流域岩石风化速率和水化学组成产生了一定的影响。     

生物传感细胞ADP1_pWHlux在水环境急性毒性检测中的应用

针对天然发光菌和以模式微生物为宿主构建的生物传感细胞在急性毒性检测应用中对测试条件要求苛刻等适用性问题,本研究将1株基因工程构建的生物传感细胞不动杆菌ADP1_p WHlux应用于急性毒性检测,建立检测方法,考察其灵敏度及检测范围.结果表明,ADP1_p WHlux发光受急性毒物的抑制,毒物剂量与发光抑制存在剂量效应关系.在4 mg·L-1Hg Cl2诱导下仅5 min可作出响应,暴露30~60 min后可以给出较为准确的结果.对Hg Cl2的检出限可达0.04 mg·L-1.对我国生活饮用水卫生标准的指标中Be2+、Ba2+、Cu2+、Ni2+检出效果明显,对Be2+、Ba2+、Cu2+的检测范围均在0.025~250 mg·L-1,对Ni2+的检测范围在0.002 5~250 mg·L-1,对Pb2+、Br O-3、Cl O-2的检出限均在0.002 5 mg·L-1,对Cl O-3检出限为0.025mg·L-1.采用ADP1_p WHlux生物传感细胞检测方法对北京市清河水环境急性毒性进行评价,表明ADP1_p WHlux生物传感细胞检测方法可用于污染水样检测.     

High aspect ratio micromachining of glass by electrochemical discharge machining (ECDM)

Micromachining of glass is essential for several microfluidic components, micro-pumps, micro-accelerometers, micro-reactors, micro-fuel cells and several biomedical devices. Unique properties such as high chemical resistance, thermal stability and transparency give glass scope for additional applications. However, poor machinability of glass is a major constraint, especially in high aspect ratio applications of glass in microsystem technology. Micro electrochemical discharge machining (micro ECDM) is an emerging nontraditional fabrication method capable of micromachining ceramic materials like glass. While surface features less than 100 μm have been successfully machined on glass, machining high aspect features is a challenge. Machining accuracy at high depths is severely affected due to overcut and tool wear. In this paper, high aspect ratio microtools fabricated in-house have been used for deep microhole drilling on glass using low electrolyte concentration. An aspect ratio of 11 has been achieved. The results show that lower electrolyte concentration reduced overcut by 22%, thus increasing the aspect ratio of the micro holes. Lowering the electrolyte concentration also reduced the tool wear and hole taper by 39% and 18% respectively.     

曝气生物滤池处理性能影响因素实验研究

采用上向流曝气生物滤池处理生活污水,考察了气水比、水力负荷、有机负荷、滤料层高度等因素对曝气生物滤池处理性能的影响。结果表明,气水比为5：1时,COD和NH3-N的去除率分别为87．6％和60．1％;水力负荷在0．21—0．86m^3／（m^2·h）的条件下,COD的去除率随水力负荷的增加降幅较小,NH3-N的去除率下降明显;有机负荷在1．15～2．96kg／（m^3·d）的条件下,BAF表现出很好的抗有机负荷冲击能力。BAF对有机物的去除主要发生在滤料层0～70cm段,对NH3-N的硝化主要发生在滤料层40—100cm段。     

进水比例对水解反应器出水水质的影响研究

针对城镇污水处理厂进水SS/BOD偏高、C/N比偏低的问题,通过对现有水解池结构进行改造,设置两层布水器,两层布水器之间形成污泥水解区,以强化污泥水解,改善出水水质.试验通过改变上下层布水器进水比例,力求最佳进水比例,使水解反应器起到初沉池作用的同时要提高废水的可生化性,以指导此类水解反应器的大规模应用.结果表明,4种进水比例均对COD和SS去除有不同的去除效果,但进水比例为1∶1较其他3种进水比例能够大幅提高出水中SCOD/COD比值和挥发性脂肪酸(VFA)浓度.以改善出水可生化性为原则,进水比例为1∶1时为最佳进水比例,即底部布水器进水50%,上层布水器处进水50%,既能为后续处理减少COD和SS的处理负担,又能提高出水的可生化性.     

Modified ADM1 for modeling free ammonia inhibition in anaerobic acidogenic fermentation with high-solid sludge

Anaerobic acidogenic fermentation with high-solid sludge is a promising method for volatile fatty acid (VFA) production to realize resource recovery. In this study, to model inhibition by free ammonia in high-solid sludge fermentation, the anaerobic digestion model No. 1 (ADM1) was modified to simulate the VFA generation in batch, semi-continuous and full scale sludge. The ADM1 was operated on the platform AQUASIM 2.0. Three kinds of inhibition forms, e.g., simple inhibition, Monod and non-inhibition forms, were integrated into the ADM1 and tested with the real experimental data for batch and semi-continuous fermentation, respectively. The improved particle swarm optimization technique was used for kinetic parameter estimation using the software MATLAB 7.0. In the modified ADM1, the K_s of acetate is 0.025, the k_m,ac is 12.51, and the K_{I_NH3} is 0.02, respectively. The results showed that the simple inhibition model could simulate the VFA generation accurately while the Monod model was the better inhibition kinetics form in semi-continuous fermentation at pH 10.0. Finally, the modified ADM1 could successfully describe the VFA generation and ammonia accumulation in a 30 m³ full-scale sludge fermentation reactor, indicating that the developed model can be applicable in high-solid sludge anaerobic fermentation.     

Investigation of nuclear enzyme topoisomerase as a putative molecular target of monohaloacetonitrile disinfection by-products

Disinfection by-products occur widely as the unintended effect of water disinfection and are associated with toxicity and adverse human health effects. Yet the molecular mechanisms of their toxicity are not well understood. To investigate the molecular basis of hyperploidy induction by monohaloacetonitriles, the interaction of monohaloacetonitriles with topoisomerase Ⅱ in Chinese hamster ovary cells was examined. We showed a concentration-dependent inhibition of DNA decatenation activity of topoisomerase under acellular conditions while in vitro monohaloacetonitrile treatment expressed mixed results. The working hypothesis, that topoisomerase Ⅱ is a molecular target of monohaloacetonitriles, was only partially supported.Nevertheless, this research serves as a starting point toward molecular mechanisms of toxic action of monohaloacetonitriles.     

新疆某新建广播电视塔周边环境的辐射环境影响预测与分析研究

对新疆某地区新建广播电视塔周边环境20 m~500 m,离地高度0 m~200 m的电磁辐射影响进行预测,探寻此范围内电磁辐射最高值覆盖区域,说明广播电视塔周围电磁场的分布情况及变化趋势,得出距广播电视塔的水平安全距离及周围高层建筑物的限制高度,以期为电视发射塔电磁辐射防护措施的制定提出切实可行、针对性强的建议,从而为环保部门管理及日益增多的电磁辐射投诉提供依据.研究表明:电视塔周围的高层建筑物外的电磁场强度随着高度的提高而增大.     

基于ABR-MBR组合工艺优化反硝化除磷性能的研究

基于ABR-MBR一体化反应器,以低C/N比生活污水为研究对象,结合厌氧折流板反应器(ABR)微生物相分离的特性,通过优化与ABR优质供碳和脱氮除磷相耦合的膜生物反应器(MBR)硝化液回流比以实现高效反硝化除磷,并对ABR-MBR污泥回流比进行优化.结果表明,在ABR段有机负荷为2.0 kg·(m3·d)-1、系统的水力停留时间(HRT)为9 h、泥龄(SRT)为15 d,系统获得最优的处理效果时的硝化液回流比和污泥回流比分别为300%和100%.其中TN和溶解性PO3-4-P平均去除率分别达84%和94%,ABR中反硝化除磷量可达系统总去除量的87%,平均出水TN和溶解性PO3-4-P浓度分别为12.98 mg·L-1和0.43 mg·L-1.