有机气溶胶组分对六氯苯光解的影响

以高压汞灯为光源,分别研究了六氯苯在正己烷和邻苯二甲酸二异辛酯(DIOP)为有机气溶胶表层模拟介质时的光解,发现六氯苯在正己烷和DIOP中的光解半衰期分别约为<5 min和5 h,相差70倍以上.研究发现蒽醌和甲氧酚类气溶胶组分对六氯苯的光解具有光敏化作用,其反应机制可能分别为能量转移和抽氢反应.六氯苯光解的主要产物是五氯酚.     

Analysis of regional and temporal characteristics of PM10 during an Asian dust episode in Korea

This study analyzes the regional and temporal distributions of PM10 concentrations observed in major metropolitan cities in Korea before, during and after a recent Asian dust episode in 2002. There were spatial and temporal variations in PM10 concentrations among the mid-western, the southwestern, the southeastern, and the southern parts of Korea during this Asian dust period due to the different air mass movement time and the different wind directions and speeds of prevailing winds in each city or region. The origins of the three-day Asian dust episode were identified by an analysis of two-day backward isentropic air trajectories. The different origins for each day also significantly contributed to the spatial and temporal variations in PM10 concentrations. A significant relationship was found between PM10 concentrations on the day preceding the first peak day and the first peak day of the Asian dust period but only in the mid-western areas. The concentrations of PM10 just after the Asian dust episode were much higher than those just before. There was a significant increase in a coarse fraction, having soil origins, of particles during the Asian dust episode. Concentrations of Mn, Fe, Ni and Cr extracted from the total suspended particulate (TSP) samples collected in 7 cities during the Asian dust episode were much higher when compared with other days in 2001. However, the Asian dust did not consistently increase the concentrations of lead, cadmium and copper as they are influenced by local sources such as local traffic or industrial emissions.     

Adsorption of branched alkylbenzene sulfonate onto styrene and acrylic ester resins

In this study, a series of acrylic ester resins were prepared and characterized. The adsorption behaviors of sodium 6-dodecyl benzenesulfonate (6-NaDBS) on styrene resin XAD-4 and acrylic ester resins have been studied. As compared to commercial acrylic ester resins Amberlite XAD-7 and Diaion HP2MG, YWB-38, one of the as-prepared resins, exhibits better adsorption properties toward 6-NaDBS. The experimental equilibrium data were fitted to the Langmuir and double-Langmuir models. The two models provide very good fit for all acrylic ester resins over the temperature range studied, whereas fitted results for styrene resin XAD-4 are less accurate. The investigation indicates that the adsorbate molecules are directly adsorbed on acrylic ester resins as a bi-layer, while the molecules are adsorbed on XAD-4 as monolayer formation followed by the establishment of bi-layer. Adsorption kinetics and elution processes were also investigated for further exploring the adsorption behavior and mechanism on styrene resin XAD-4 and YWB-38.     

"三大定律"警示基层安全管理工作

近两年来,频繁发生的"12·23重庆井喷"、"4·15重庆天原化工厂氯气泄漏"、"吉化11·13苯泄露事件"等等安全事故,让人触目惊心.从这些事故原因中,我们不难看到钻井作业卸掉"防喷阀"、危险化学品车辆押运员"逃逸"、化工厂职工现场"处置不当"等不安全状态(侥幸心理和麻痹大意思想)是导致这些事故发生的直接原因.我们安全管理人员在分析以上事故原因,吸取惨痛教训的同时,不能忽视事故发生的规律,并且应注重"安全管理三大定律"对基层安全管理和安全培训教育工作的启示.     

耕作制度对川中丘陵区冬灌田CH4和N2O排放的影响

采用静态暗箱/气相色谱法连续2 a田间原位测定,研究川中丘陵区冬灌田CH₄和N₂O的排放特征和不同耕作制度对冬灌田CH₄和N₂O排放的影响.结果表明,1a只种1季中稻冬季灌水休闲的冬灌田(PF),在水稻生长期,CH₄平均排放通量为(21.44±1.77)mg·(m²·h)^-1,非水稻生长期为(3.77±0.99)mg·(m²·h)^-1,分别大大低于以前文献报道的在西南其它地方观测值;全年CH₄排放量以水稻生长期CH₄排放量为主,非水稻生长期CH₄排放量仅占全年总排放量的23.2%.冬灌田N₂O排放通量年均值为(0.051±0.008)mg·(m²·h)^-1,且主要集中在水稻生长季,非水稻生长期N₂O排放量仅占全年总排放量的8.1%.在采用水旱轮作制后,冬灌田CH₄排放量大大降低,稻-麦轮作(RW)和稻-油菜轮作(RR)全年CH₄排放量分别为PF的43.8%和40.6%.但冬灌田改为水旱轮作制后,N₂O排放量显著增大,RW和RR的N₂O年排放量分别是PF的3.7倍和4.5倍.综合考虑冬灌田在采用不同耕作制度后排放CH₄和N₂O的全球增温潜势(GWP),无论是短时间尺度还是长时间尺度,采用3种耕作制度全年所排放的CH₄和N₂O所产生的综合GWP都为:PF RW≈RR.在20a、100a和500a时间尺度上,PF分别约是RW和RR的2.6、2.1和1.7倍.冬灌田改为水旱轮作制度后能大大减少CH₄和N₂O所产生的综合GWP.     

潮土施镍对小白菜的生物效应及其临界值研究

研究潮土施Ni对盆栽蔬菜的生态效应,并通过小白菜生物量的变化、地上部茎叶Ni质量比及土壤有效态Ni质量比来表征土壤Ni污染的毒性临界值.结果表明,潮土施Ni对蔬菜未表现出增产效应.施Ni量低于25 mg/kg,其生物产量无明显降低.随施Ni量的增加,生物产量呈显著下降,生物量变化与Ni质量比呈高度负相关.潮土施Ni增加茎叶和根系中Fe,Mn,Ca,Mg元素质量比,降低Cu,Zn元素质量比.4种性质不同的提取试剂提取的土壤有效态Ni质量比与植物Ni吸收均呈高度正相关,较好地反映了植物的危害状况,且以DTPA提取效果最佳.以生物减产量突变点为依据,确定潮土施Ni毒害临界值为:土壤全量Ni为41.86 mg/kg,有效态Ni质量比为2.55mg/kg(DTPA)和茎叶Ni质量比为22.39 mg/kg.     

示踪技术用于气体泄漏扩散模拟的多元线性回归分析

采用江苏工业学院油气储运安全综合实验模型平台,利用示踪技术(以CO2为示踪剂),模拟了有害气体瞬时泄漏扩散的整个过程.并结合多元线性回归分析的基本方法,定量分析了气体泄漏扩散过程,建立了多元线性回归模型,初步确定了泄漏气体浓度与相关物理量的变化关系,在此基础上得到了2个定量评价指标:确定性系数R=0.991,相关系数r=0.995.研究表明,在实验室建立的试验模型能较好地反映现实情况,模型仿真度较高,数据拟合效果较好.研究可为评价模型的相似性提供理论参考,对有害气体泄漏扩散事故应急救援、实施有效的现场控制,具有一定的科学参考价值.     

卷烟厂通风空调系统中聚积物燃烧特性研究

选取某烟厂车间通风空调系统,分别对风管内表面及设备部件表面附着的聚积物进行实测与分析.通过对所采集样品的C、H、N、S等的元素分析、工业分析、自然状态下的着火点参数以及灰熔融性参数等的实验分析,得到了烟厂建筑的通风空调系统中聚积物的燃烧特性,为工业建筑火灾的预测评价及防排烟设计提供了参考.     

现代城市居住区的防盗安全问题研究

针对现代城市居住区防盗安全问题日益突出的情况,从住宅建筑方面入手,对城市居住区的防盗安全问题进行研究分析,并提出相应的解决措施.其中分别对住宅建筑的窗、住宅平立面、阳台、住宅楼梯间、雨篷、管道和空调主机七个细节部位进行了防盗分析;在安全设计时充分考虑各个细节部位之间的联系,本着"相互促进,相辅相成"的原则,对它们的整体布局、安放位置和尺寸等方面提出了改进方案,并实施了防盗安全设计.     

微生物法液相氧化SO2

通过对酸性水溶液、含Fe³⁺水溶液、含Fe²⁺水溶液、细菌菌液和细菌培养基水溶液脱除二氧化硫的实验,探讨了微生物液相氧化二氧化硫的途径.以液相中SO₄^2-浓度考察了Fe³⁺浓度、Fe²⁺浓度、进口SO₂浓度以及温度对脱硫成酸的影响.微生物脱硫有2种机制:一是直接氧化作用,即氧化亚铁硫杆菌(Thiobacillus ferrooxidans)将S(IV)氧化成S(VI);二是间接催化氧化,氧化亚铁硫杆菌在酸性条件下具有快速氧化Fe²⁺成Fe³⁺,增强Fe³⁺对SO₂的液相催化氧化能力,研究表明微生物脱硫以间接催化氧化为主.在浓度0～1.2g/L之间,Fe³⁺和Fe²⁺浓度越高,脱硫效果越好,氧化亚铁硫杆菌表现出对Fe³⁺/Fe²⁺体系氧化SO₂的强化效果.入口SO₂浓度越高,细菌脱硫效率越低,但液相中SO₄^2-浓度随进口SO₂浓度增加变化不大.温度对微生物脱硫影响较大,最佳脱硫温度为30～40℃.