铁/钴氮氟掺杂二氧化钛膜的制备研究

通过溶胶-凝胶法制备Fe,N,F-TiO2膜和Co,N,F-TiO2膜的光催化剂,以亚甲基蓝为模型污染物,探讨了制备两种膜的最佳煅烧温度、镀膜层数和铁/钴掺杂量。结果表明,当煅烧温度400℃,镀膜层数4层,Fe/Ti=0.05%,Co/Ti=0.02%时,得到的Fe,N,F-TiO2膜和Co,N,F-TiO2膜的可见光催化活性最高。其中Fe,N,F-TiO2膜的光催化活性要略优于Co,N,F-TiO2膜。     

北京东南郊土壤剖面氟喹诺酮类抗生素分布特征

采用Geoprobe在北京东南郊地区实施了土壤剖面钻探,针对8种不同类型土地利用状况的土壤剖面进行土壤采集工作,11个采样点共采集86个土壤样品,分析了土壤样品的理化参数,并且采用高效液相色谱法对土壤样品中5种氟喹诺酮类抗生素(FQs)进行了定量分析.结果表明,北京地区土壤样品中5种氟喹诺酮类抗生素总含量的平均值为46.1μg·kg-1,组成以氧氟沙星(OFL)为主,其次为诺氟沙星(NOR),而恩诺沙星(ENR)、环丙沙星(CIP)和洛美沙星(LOM)的含量很低;不同土壤剖面中氟喹诺酮类抗生素的含量和组成差异明显.5种氟喹诺酮类抗生素总含量的平均值随土壤深度的增加呈现降低的趋势.OFL、NOR、LOM和ENR的平均含量随着深度增加而降低;CIP的平均含量随深度增加先降低后升高.对42个位于浅层(0~3 m)的土壤样品进行模糊聚类分析,结果表明,蔬菜大棚、树林、再生水灌区、地下水灌区(清灌区)、养殖场、排污河沉积物的浅层土壤样品中的喹诺酮类抗生素具有相似的组成特征,即抗生素污染水平较低、种类较少;而制药企业及垃圾填埋场的组成特征与前者明显不同,即抗生素污染水平中等、种类较多.     

Characteristics of ozone and ozone precursors (VOCs and NOx) around a petroleum refinery in Beijing, China

A field measurement campaign for ozone and ozone precursors(VOCs and NOx) was conducted in summer 2011 around a petroleum refinery in the Beijing rural region. Three observation sites were arranged, one at southwest of the refinery as the background, and two at northeast of the refinery as the downwind receptors. Monitoring data revealed the presence of serious surface O3 pollution with the characteristics of high average daily mean and maximum concentrations(64.0 and 145.4 ppbV in no-rain days, respectively) and multi-peak diurnal variation. For NOx, the average hourly concentrations of NO2 and NO were in the range of 20.5–46.1 and 1.8–6.4 ppbV, respectively. For VOC measurement, a total of 51 compounds were detected. Normally, TVOCs at the background site was only dozens of ppbC, while TVOCs at the downwind sites reached several hundreds of ppbC. By subtracting the VOC concentrations at background, chemical profiles of VOC emission from the refinery were obtained, mainly including alkanes(60.0% ± 4.3%), alkenes(21.1% ± 5.5%) and aromatics(18.9% ± 3.9%). Moreover, some differences in chemical profiles for the same measurement hours were observed between the downwind sites; the volume ratios of alkanes with low reactivity and those of alkenes with high reactivity respectively showed an increasing trend and a decreasing trend. Finally, based on temporal and spatial variations of VOC mixing ratios, their photochemical degradations and dispersion degradations were estimated to be 0.15–0.27 and 0.42–0.62, respectively, by the photochemical age calculation method, indicating stronger photochemical reactions around the refinery.     

小小公示栏浓浓关爱情

2005年12月6日,中国石化巴陵石化尿素装置"煤代油"改造的配套部分--投资约1.06亿元的"一(锅)炉"改扩建工程顺利竣工点火试运行.在点火仪式旁的工棚的墙上,一块"安全公示栏"引人注目.它,饱含着承建该项目的中国石化五建公司岳阳项目部无时无刻对全体建设者的提醒:生命可贵,安全第一!     

林地土壤氟的形态分布特征及其影响因素

采用连续分级浸提法分析了13个具有代表性的不同类型林地土壤中氟的赋存形态特征,探讨了土壤理化性质对氟形态分布的影响。结果表明,研究区域土壤全氟含量变化较大,为62.68～970.39 mg/kg,以残余态为主,其中水溶态、可交换态、铁锰氧化物态、有机束缚态和残余态氟含量平均值分别为0.59、0.02、0.50、0.79和374.98 mg/kg。相关性分析表明,不同形态氟之间存在一定的相关性,且土壤性质也影响氟的形态分布,如水溶态氟含量与土壤pH呈显著正相关,与黏粒、铝氧化物呈显著负相关;可交换态氟含量与锰氧化物含量呈显著负相关。基于土壤阳离子交换量、黏粒、铝氧化物和锰氧化物的多元回归模型,可较好地预测水溶态氟、可交换态氟和铁锰氧化物态氟的含量,其决定系数r~2为0.53～0.70。     

ODS替代制冷剂的发展态势和我国的对策建议

本文阐述了全球范围内关于HFCs应用的不同立场，以及由此出现的对于同一类型制冷空调系统的多种制冷剂方案。预测了制冷剂的可能发展态势，并对我国的对策提出了若干建议。     

氟氯烃及其替代工质对环境的影响

氟氯烃及其替代工质对环境的影响＊随着制冷工业的迅速发展,在制冷设备的生产及使用过程中泄漏的氟氯烃类（ＣＦＣｓ）致冷剂,挥发而进入大气中,导致大气臭氧层的破坏,并加重了温室效应。１９９０年,在伦敦召开的蒙特利尔议定书缔约国第二次会议上,提出了在更短时间...     

渭河发电厂生活饮用水除氟试验研究

本文总结了用活性氧化铝和羟基磷酸钙去除渭河电厂生活饮用水中氟的条件试验和对比试验结果。