高炉共处置固体废物低温段Pb Cd的吸附/冷凝动力学特征

利用管式回转炉和控温立式炉联用装置模拟炼铁高炉,对Pb、Cd在共处置过程中低温段的吸附/冷凝特性进行了研究,通过建立吸附/冷凝动力学模型,分析共处置过程中Pb、Cd在非热力学平衡状态下的迁移转化规律.结果表明:高炉共处置固体废物低温段对Pb、Cd的吸附/冷凝作用以冷凝为主.进入控温立式炉的重金属去向分三部分:①冷凝在管壁上,这部分的Pb、Cd分别占Pb、Cd入炉总量的42%～49%、45%～50%;②吸附在炉料上,其中Pb、Cd分别占各自入炉总量的23%～26%、23%～25%;③随烟气释放到空气中,这部分Pb、Cd分别占各自入炉总量的25%～35%、25%～32%.Pb、Cd在炼铁炉料上的吸附/冷凝量均随时间的增加而升高,随温度的升高而降低.炼铁炉料对Pb、Cd的吸附/冷凝动力学可采用双常数速率方程拟合,研究得到Pb、Cd的吸附/冷凝表观活化能分别为6.813、5.839 kJ/mol.      

Detection and Phylogenetic Analysis of the Hepatitis E Virus in a Canadian Swine Production Network

Viral contamination along the production chain is a significant concern in both food safety and livestock health. Pigs have been reported to act as a reservoir for zoonotic viruses, sometimes emerging ones, and epidemiological studies have shown direct links between the consumption of uncooked pork offal and cases of hepatitis caused by the hepatitis E virus (HEV) genotype 3 in humans. The presence of HEV in swine herds has been reported, but its dissemination in pork production environments is still unknown. To investigate viral contamination sources in the swine industry, 452 environment and fecal samples, including samples from livestock transportation vehicles, were collected over a period of 11 months from ten farms and one slaughterhouse that together represent a single production network. Hepatitis E virus RNA was detected by nested RT-PCR in 32 samples from both inside and outside farm buildings, on trucks, and, mostly, from fomites collected in the slaughterhouse yard, such as on a utility vehicle. Phylogenetic analysis showed a wide diversity of HEV genotype 3 strains, similar to human and swine strains previously found. According to the results of this study, the movements of trucks and utility vehicles might play an important role in HEV dissemination on a slaughterhouse site and throughout an entire network.     

In vitro evaluation of inorganic and methyl mercury mediated cytotoxic effect on neural cells derived from different animal species

To extend the current understanding of the mercury-mediated cytotoxic effect,five neural cell lines established from different animal species were comparatively analyzed using three different endpoint bioassays:thiazolyl blue tetrazolium bromide,3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide assay(MTT),neutral red uptake assay(NRU),and Coomassie blue assay(CB).Following a 24-hr exposure to selected concentrations of mercury chloride(HgCl_2) and methylmercury(Ⅱ) chloride(MeHgCl),the cytotoxic effect on test cells was characterized by comparing their 50%inhibition concentration(IC_(50)) values.Experimental results indicated that both these forms of mercury were toxic to all the neural cells,but at very different degrees.The IC_(50)values of MeHgCl among these cell lines ranged from 1.15±0.22 to 10.31 ± 0.70 μmol/L while the IC_(50) values for HgCl_2 were much higher,ranging from 6.44 ± 0.36 to 160.97±19.63 μmol/L,indicating the more toxic nature of MeHgCl.The IC_(50) ratio between HgCl_2and MeHgCl ranged from 1.75 to 96.0,which confirms that organic mercury is much more toxic to these neural cells than inorganic mercury.Among these cell lines,HGST-BR and TriG44 derived from marine sea turtles showed a significantly high tolerance to HgCl_2 as compared to the three mammalian neural cells.Among these neural cells,SK-N-SH represented the most sensitive cells to both chemical forms of mercury.     

Estimating emissions from crop residue open burning in China based on statistics and MODIS fire products

With the objective of reducing the large uncertainties in the estimations of emissions from crop residue open burning, an improved method for establishing emission inventories of crop residue open burning at a high spatial resolution of 0.25°× 0.25° and a temporal resolution of1 month was established based on the moderate resolution imaging spectroradiometer(MODIS) Thermal Anomalies/Fire Daily Level3 Global Product(MOD/MYD14A1). Agriculture mechanization ratios and regional crop-specific grain-to-straw ratios were introduced to improve the accuracy of related activity data. Locally observed emission factors were used to calculate the primary pollutant emissions. MODIS satellite data were modified by combining them with county-level agricultural statistical data, which reduced the influence of missing fire counts caused by their small size and cloud cover. The annual emissions of CO_2, CO, CH_4,nonmethane volatile organic compounds(NMVOCs), N_2O, NO_x, NH_3, SO_2, fine particles(PM2.5),organic carbon(OC), and black carbon(BC) were 150.40, 6.70, 0.51, 0.88, 0.01, 0.13, 0.07, 0.43,1.09, 0.34, and 0.06 Tg, respectively, in 2012. Crop residue open burning emissions displayed typical seasonal and spatial variation. The highest emission regions were the Yellow-Huai River and Yangtse-Huai River areas, and the monthly emissions were highest in June(37%).Uncertainties in the emission estimates, measured as 95% confidence intervals, range from a low of within ±126% for N_2O to a high of within ± 169% for NH_3.     

春季东海营养盐跨陆架输运通量的初步估算

利用2011年5月的调查资料,分析了春季东海营养盐分布特征。受长江冲淡水影响,表层长江口附近营养盐浓度较高; 外海受黑潮表层水的影响营养盐浓度较低。计算并分析了跨200 m等深线的营养盐输运通量,结果表明黑潮在台湾东北部和九州岛西南部入侵陆架并将营养盐输运到陆架上,中段(26°N~29°N)则是营养盐向外输运。春季黑潮跨过200 m等深线向东海陆架的体积输运净通量为0.44 Sv,DIN、PO₄-P、SiO₃-Si通量分别为8.93 kmol/s、0.46 kmol/s、8.22 kmol/s。春季通过台湾海峡的营养盐DIN、PO₄-P、SiO₃-Si通量分别为6.65 kmol/s、0.41 kmol/s、6.52 kmol/s。表明春季台湾暖流对东海陆架海域营养盐的贡献与黑潮的贡献相当。     

赤泥强化型河岸带模拟系统对再生水中磷去除效果的研究

为了探讨不同比例赤泥施入量对再生水磷去除效果的影响以及植物在再生水净化过程的作用,利用赤泥中富含钙、铁、铝等金属氧化物对磷具有较强吸附性能的特点,构建了室内赤泥强化型河岸带模拟系统.结果表明,赤泥最适施入质量分数为2.5%～5.0%,此时TP去除率为82%～76%,出水磷浓度约为0.22～0.29 mg/L,SRP/TP比值为74%～75%.当赤泥施入量为2.5%时,相比无植物系统,有植物系统的磷净化效率提高了4%,约为86%,出水磷浓度为0.17mg/L.这些结果表明赤泥可以适当比例直接掺混于河岸带的土壤中,这为其提高对再生水中磷的去除能力提供了一种新途径.     

介体厌氧催化活性艳红K-2BP脱色及构效特性研究

研究了筛选出的4种结构相似的醌类氧化还原介体对活性艳红K-2BP厌氧脱色的促进作用,并分析了介体促进效果与其化学结构活性相关性. 在35℃中温厌氧条件下,采用间歇批量实验法,测定不同体系中介体催化活性艳红K-2BP脱色效果.结果表明,①结构相似的醌类氧化还原介体蒽醌(AQ)、1,5-二氯蒽醌(1,5-AQ)、1,8-二氯蒽醌(1,8-AQ)和1,4,5,8-四氯蒽醌(1,4,5,8-AQ),均促进活性艳红K-2BP脱色,反应速率提高了1.4～3倍;②当醌类介体投加浓度为4 mmol·L^-1,活性艳红K-2BP染料浓度为300 mg·L^-1时,促进作用由大到小的顺序为:1,8-AQ>1,5-AQ>AQ>1,4,5,8-AQ;③ 当活性艳红K-2BP染料浓度为300 mg·L^-1时,1,8-AQ促进效果最佳且脱色速率常数随1,8-AQ浓度的增加而增加呈线性关系;④介体促进效果与介体取代基团数量、位置和电子共轭效应相关.本研究初步建立了氧化还原介体定性/定量构-效关系数学模型,探究和完善非水溶性氧化还原介体催化强化理论体系.     

SiO2纳米颗粒对小球藻(Chlorella pyrenoidosa)生长活性的影响

从Si02纳米颗粒对小球藻(Chlorella pyrenoidosa)生长活性的影响来探讨纳米材料的生物安全性问题.结果表明Si02纳米颗粒降低了小球藻的生物量和蛋白含量,并可以附着在细胞表面和进入细胞内部,造成了细胞的形变和结构损伤,从而抑制了小球藻的正常生长活性.Si02纳米颗粒对小球藻具有一定的毒性效应.     

兰州市工业固体废物污染现状与控制对策

本文通过对兰州市工业固体废物的产生量及处置现状的详细调查,深入分析了兰州市工业固体废物的污染特征以及固体废物处理处置过程中存在的问题;根据兰州市经济发展承受能力,对工业固体废物的增长趋势进行了预测;并针对兰州市当前工业固体废物的综合处理状况和工业结构特征,从立法、执法、管理等方面提出了相应的控制对策和建议.     

浅谈石化企业体系审核策划的增值

从审核方案策划和审核实施策划两个方面就审核策划的增值方案制订、实施方式和途径进行了探讨。