复合垂直流人工湿地微生物特征对典型污水的响应差异

污水性质是影响人工湿地微生物特征的重要因子,而微生物对人工湿地污染物净化功能的发挥至关重要. 运用两组IVCW(复合垂直流人工湿地)分别处理模拟生活污水和污水处理厂尾水,比较研究两组系统下行流、上行流池的基质酶活性及硝化反硝化强度,并通过脂肪酸甲酯图谱分析系统中的微生物群落结构,以解析人工湿地微生物特征对两种污水的响应差异. 结果表明:处理生活污水的IVCW下行流池中脱氢酶、过氧化氢酶、脲酶及硝酸盐还原酶活性均显著高于其他单元,四者平均值分别为其他单元的2.8~4.6、7.9~10.3、19.3~41.7和4.5~10.8倍. 处理生活污水IVCW基质的硝化强度是尾水处理系统对应单元的1.4~5.3倍(下行流)和1.3~3.9倍(上行流),而两组IVCW对应单元基质的反硝化强度之间无显著差异. IVCW下行流池中特征脂肪酸比值及微生物群落结构受污水类型的影响较小,均以厌氧细菌和革兰氏阳性菌为优势菌;上行流池微生物群落结构则受到污水类型的一定影响,真菌的相对丰度较高. 两种污水对IVCW基质酶活性和硝化强度的影响高于对反硝化强度和微生物群落结构的影响.      

Gasification applicability study of polyurethane solid refuse fuel fabricated from electric waste by measuring syngas and nitrogenous pollutant gases

To recycle polyurethane foam waste generated from electric appliance recycling centers for use as fuel in a gasification process, polyurethane solid refuse fuel fabricated as pellets was analyzed for the characteristics of elemental composition, proximate analysis, heating value, and thermo-gravimetric testing. It has a high heating value of 29.06 MJ/kg with a high content of combustibles, which could be feasibly used in any thermal process. However, the nitrogen content, of up to 7 %, was comparably higher than for other fuels such as coal, biomass, and refuse-derived fuel, and may result in the emission of nitrogenous pollutant gases of HCN and NH₃. By conducting gasification experiments on polyurethane solid refuse fuel in a fixed-bed reactor, a syngas with a heating value of 9.76 kJ/m³ and high content of both H₂ and CO were produced with good gasification efficiency; carbon conversion 54 %, and cold gas efficiency 60 %. The nitrogenous pollutant gases in syngas were measured at the concentrations of 160 ppm hydrogen cyanide and 40 ppm ammonia, which may have to be reduced using proper cleaning technologies prior to the commercialization of gasification technology for polyurethane waste.     

翅片式防爆柴油机排气冷却器烟气侧数值分析

建立了翅片式防爆柴油机排气冷却器的计算模型,通过FLUENT软件对其烟气侧进行了仿真分析,探讨了防爆柴油机排气冷却器烟气内部的流场及温度场分布规律,仿真结果与热平衡试验结果基本一致,表明建立的数值分析模型准确,为翅片式排气冷却器的设计优化提供了理论指导。     

Risk of motor vehicle accident death among 1.3 million veterans of the Iraq and Afghanistan wars

Objective: We conducted a cohort study of recent wartime veterans to determine the postservice mortality risk due to motor vehicle accidents (MVAs).

Methods: Veterans were identified from the Defense Manpower Data Center records. Deployment to te Iraq or Afghanistan war zone was determined from the Contingency Tracking System. Vital status of 317,581 deployed and 964,493 nondeployed veterans was followed from their discharge dates between 2001 to 2007 until earlier of date of death or December 31, 2009. Underlying causes of death were obtained from the National Death Index Plus.

Results: Based on 9,353 deaths (deployed, 1,650; nondeployed, 7,703), of which 779 were MVA deaths as drivers (166; 613), both cohorts had 25 to 24% lower mortality risk from all causes but had 44 to 45% higher risk of MVA deaths relative to the U.S. general population. The higher MVA mortality risk was not associated with deployment to the war zone. After controlling for age, sex, race, marital status, branch of service, and rank, the risk for deployed veterans was comparable to that of nondeployed veterans (hazard ratio = 0.91; 95% confidence interval, 0.77–1.09).

Conclusions: Veterans exhibit significantly higher risk of MVA deaths compared to the U.S. general population. However, deployment to the Iraq or Afghanistan war was not associated with the excess risk.     

Removal of tetracycline from water by Fe-Mn binary oxide

Significant concerns have been raised over the presence of antibiotics including tetracyclines in aquatic environments. A series of Fe-Mn binary oxide with different Fe:Mn molar ratios was synthesized by a simultaneous oxidation and coprecipitation process for TC removal. Results showed that Fe-Mn binary oxide had higher removal efficiency than that of hydrous iron oxide and hydrous manganese oxide, and that the oxide with a Fe:Mn molar ratio of 5:1 was the best in removal than other molar ratios. The tetracycline removal was highly pH dependent. The removal of tetracycline decreased with the increase of initial concentration, but the absolute removal quantity was more at high concentration. The presence of cations and anions such as Ca²⁺, Mg²⁺, CO₃^2- and SO₄^2- had no significant effect on the tetracycline removal in our experimental conditions, while SiO₃^2- and PO₄^3- had hindered the adsorption of tetracycline. The mechanism investigation found that tetracycline removal was mainly achieved by the replacement of surface hydroxyl groups by the tetracycline species and formation of surface complexes at the water/oxide interface. This primary study suggests that Fe-Mn binary oxide with a proper Fe:Mn molar ratio will be a very promising material for the removal of tetracycline from aqueous solutions.     

浅层地下水与地表水污染物交换关系研究——以常州市老城区为例

通过研究北市河地质结构、地表水和地下水补排关系、污染物在地表水和地下水中的迁移转化规律及转化量这3个方面来分析地下水与地表水的水力联系,发现北市河从地质角度上上游、中游具备发生水利联系的条件,而下游的发生水利联系的可能性很小;上游平水期污染物由地表水扩散到地下水,丰水期由地下水扩散到地表水;中游地区地表水的污染物扩散到地下水,而下游就没有明显的污染物扩散现象.然而并未发现地下水地表水之间有明显的相互影响.     

坡度分析在昆明盆地断层分段中的应用

地面坡度是反映地形地貌变化的关键因子,应用坡度分析一定程度上可以反映断层的展布特征。本文收集整理昆明市区附近千余份钻孔数据,筛选其中238个钻孔进行钻孔层序分层和数据库的建设,使用ArcScene软件生成研究区地表、海埂组(QhH)底部以及官渡组(Qp3G)底部地层面的三维地质模型。应用ArcGIS软件中坡度分析模块,获得各个界面的坡度图,从坡度变化特征方面对研究区5条主要断层的活动性与分段特征进行了初步探讨。     

Comparative Analysis of Viral Concentration Methods for Detecting the HAV Genome Using Real-Time RT-PCR Amplification

Hepatitis A is a major infectious disease epidemiologically associated with foodborne and waterborne outbreaks. Molecular detection using real-time RT-PCR to detect the hepatitis A virus (HAV) in contaminated vegetables can be hindered by low-virus recoveries during the concentration process and by natural PCR inhibitors in vegetables. This study evaluated three virus concentration methods from vegetables: polyethylene glycol (PEG) precipitation, ultrafiltration (UF), and immunomagnetic separation (IMS). UF was the most efficient concentration method, while PEG and IMS were very low for the recovery rate of HAV. These results demonstrate that UF is the most appropriate method for recovering HAV from contaminated vegetables and that this method combined with the real-time RT-PCR assay may be suitable for routine laboratory use.     

分流制泵站旱流放江对受纳河道水质的影响

为了探明分流制泵站旱流放江对受纳河道的影响,以上海市中心城区典型分流制系统Z泵站为例,研究了旱流放江对受纳河道水质的影响。结果显示:（1）受泵站放江的影响,河道COD、硫化物以及氨氮的增幅分别为0.23%～37.68%、7.4%～76.19%、10.60%～76.15%;（2）旱流放江污染物对河道水质的影响有显著差异,其中COD与氨氮浓度的下降主要源于水体的稀释扩散作用;而H₂S、FeS等硫化物浓度的降低则更多的受到氧化还原反应的影响;（3）Z泵站旱流放江对Z河水质的显著影响范围为泵站排放口上下游40 m范围内,对黄浦江水质的影响则总体不大。     

聚氨酯泡沫材料的粘接性能研究

介绍了常规聚氨酯泡沫材料的原料及合成;探讨了主要原料的选择,发泡剂、交联剂、催化剂等助剂的选择及化学改性聚氨酯泡沫三方面因素对聚氨酯泡沫粘接性能的变化规律的影响,并介绍了常用的几种提高聚氨酯泡沫粘接强度的方法;提出了改善聚氨酯泡沫粘接过程中存在的问题和未来的研究方向。