酸性红R在UV-蒙脱土KSF-H_2O_2体系中光降解行为研究

以紫外杀菌灯(波长为254nm)为光源,研究了酸性红R在由蒙脱土KSF和H2O2组成的类Fenton体系中的光降解行为,研究了反应体系pH、H2O2浓度对偶氮染料酸性红R光催化降解的影响,分析了酸性红R的光降解动力学规律。结果表明:对于100mg/L的酸性红R,在pH为3.0、66mg/L的H2O2和质量浓度为1g/L的蒙脱土条件下,在UV/类Fenton体系可以获得较高的反应速率,经50min的光照,酸性红R的光降解率为87.2%;而在类Fenton体系中的光降解率只有56%左右,可见UV对类Fenton体系有明显的协同作用;酸性红R的光降解动力学规律符合Langmuir-Hinshelwood方程,反应速率常数为1.82mg/(L·min)。     

走出国门：可回收利用废塑料进口企业的最佳选择

近年来,我国的可回收利用废塑料进口企业面临困境,国际贸易企业进口困难,致使使用厂缺乏原料.论述了废塑料回收加工企业前往国外产地办厂的必要性和可行性,分析了我国业内企业走出国门的优势,并对废塑料的收集和加工品种、成本核算、采购目标等方面提出建议.     

Leaching of azoxystrobin and its degradation product R234886 from Danish agricultural field sites

The objective was to estimate leaching of the fungicide azoxystrobin (methyl (αE)-2-[[6-(2-cyanophenoxy)-4-pyrimidinyl]oxy]-α-(methoxymethylene)benzene-acetate) and one of its primary degradation products R234886 ([(E)-2-(2-[6-cyanophenoxy)-pyrimidin-4-yloxyl]-phenyl-3-methoxyacrylic acid], major fraction) at four agricultural research fields (one sandy and three loamy) in Denmark. Water was sampled from tile drains, suction cups and groundwater wells for a minimum period of two years after application of azoxystrobin. Neither azoxystrobin nor R234886 were detected at the sandy site, but did leach through loamy soils. While azoxystrobin was generally only detected during the first couple of months following application, R234886 leached for a longer period of time and at higher concentrations (up to 2.1 μg L⁻¹). Azoxystrobin is classified as very toxic to aquatic organisms and R234886 as very harmful. Our study shows that azoxystrobin and R234886 can leach through loamy soils for a long period of time following application of the pesticide and thereby pose a potential threat to vulnerable aquatic environments and drinking water resources. We thus recommend the inclusion of azoxystrobin and R234886 in pesticide monitoring programmes and further investigation of their long-term ecotoxicological effects.     

R值评分方法的再学习

详细介绍了目前最常用的预报效能评价R值评分方法的基本内容和不同公式 ,分析了计算R值评分时所选用参数和使用公式不同对R值的影响。以便能正确应用R值评分方法并对R值预报效能评价结果有一清晰的认识