Sb2O5/TiO2催化超声降解甲基橙溶液

采用实验室合成的Sb2O5掺杂TiO2作为催化剂,研究各种因素对甲基橙的超声催化降解反应的影响.结果表明,在Sb2O5掺杂TiO2催化剂作用下,甲基橙的超声催化降解效果明显优于单独使用TiO2的情况.1.5%掺杂量的催化剂,用量在1.0～1.5 g/L之间,超声波频率25 kHz,输出功率1.0 W/cm2,pH为1.0～3.0时,初始浓度为20 mg/L的甲基橙水溶液,100 min左右基本可全部降解,COD去除率达到99.0%以上.Sb2O5掺杂TiO2催化超声降解有机污染物的方法具有很好的应用前景.     

Modified Edman degradation applied to hemoglobin for monitoring occupational exposure to alkylating agents

A method that can be used for the monitoring of exposure to alkylating agents in the environment is presented. It is based on the quantification of alkylated N‐terminal valines in hemoglobin, using a modified Edman degradation procedure. The detection limit (GC/electron capture detector or GC/MS) is increased by two magnitudes of ten when using pentafluorophenyl isothiocyanate instead of phenyl isothiocyanate in the derivatization step. As little as one nmole N‐(—2 hydroxyethyl)valine per gram hemoglobin can be detected under practical conditions.     

水浮莲干体对甲基橙的吸附研究

研究了水浮莲干体对模拟染料废水中甲基橙(MO)的吸附行为,考察吸附时间、溶液初始pH值、水浮莲干体用量和MO初始质量浓度等因素对MO吸附的影响.结果表明,在MO溶液初始pH值为5.5、初始质量浓度为25 mg·L-1条件下,添加12.5g·L-1粒径为0.250～0.425 mm的水浮莲干体,于25℃条件下以120 r·min-1振荡吸附90 min后,MO吸附率可达72.1％.酸性环境有利于MO吸附;一定范围内,水浮莲干体用量的增加以及MO初始浓度的升高都会导致吸附率升高.水浮莲干体对MO的吸附过程更符合Freundlich吸附等温方程,Lagergren准二级动力学方程更适合模拟其吸附动力学行为.随温度升高,MO平衡吸附量呈减少趋势.水浮莲干体及浸出液中Cr、Ni、Cu、As、Cd和Pb含量远低于GB 5085.3-2007 《危险废物鉴别标准浸出毒性鉴别》中的限量值,因此将水浮莲干体作为新型吸附剂应用于染料废水处理,不会导致二次污染.     

Monitoring toxicity of an azo dye methyl red and a heavy metal Cu,using plant and animal bioassays

Toxicities of an azo dye methyl red and a heavy metal copper (Cu) were quantified, using growth and mortality as end points, in four plant species and three animal species by subjecting them to short-term (4 days for animals, 10 days for plants) static bioassays. Lemna aequinoctialis Welwitch (EC₅₀: 7–16 ppm) was found to be the most sensitive species for methyl red, Ceratophyllum demersum L. (EC₅₀: 25 ppm) and Lactuca sativa L. (EC₅₀: 56 ppm) were intermediate, while Oryza sativa L. shows reduction in seedling vigor (9–27%) of <50%, being the least sensitive amongst the tested plant species. Methyl red toxicity is almost 3–5-fold higher in growing medium (pH = 5.8–6.0), even at high nutrient levels, while Cu toxicity is higher in nutrient-poor alkaline medium at alkaline pH (8.3–8.7; EC₅₀: Ceratophyllum = 104–200 ppb; Lemna = 100–170 ppb) compared to nutrient-rich acidic medium (pH = 5.4–5.7; EC₅₀: Ceratophyllum = 2600–3175 ppb; Lemna = 4350–4715 ppb). Rice tolerance (EC₅₀: 6500 ppb) was found to be higher than hydrophytes while lettuce was most tolerant to Cu. Fish sensitivity toward the test chemicals was almost parallel to Ceratophyllum and Lemna [Gambusia affinis Baird and Gerard (LC₅₀: 250 ppb for Cu) and Poecilia reticulata Peters (LC₅₀: 24 ppm for methyl red)]. Similar to the plants, dye toxicity increased markedly (LC₅₀: 7 ppm) in the acidic medium (pH = 6.0). Amongst the tested organisms, Daphnia was found to be most sensitive to methyl red (EC₅₀: 6 ppm) while its sensitivity to Cu (EC₅₀: 230 ppb) was similar to hydrophytes and fish. Initially, the combination of dye and Cu (at their sublethal concentrations) had additive effects in duckweed, while dye concentration ruled afterward. These results indicate that hydrophytes and animals are equally sensitive toward the test chemicals. Dye toxicity in hydrophytes and fish was pH dependent, while in the case of Cu, it is related to the nutrient status of the growth medium of plants.     

Photocatalytic degradation of methyl orange using ZnO nanorods

Nanosized ZnO rods were synthesized using a microwave-assisted aqueous method. High molecular weight polyvinyl alcohol was used as a stabilizing agent. Size, surface morphology, and structure were investigated using transmission electron microscopy (TEM), scanning electron microscopy (SEM), and X-ray diffraction (XRD). SEM and TEM images show that ZnO nanorods have diameters of about 50?nm and lengths of a few micrometers. The XRD pattern reveals that ZnO nanorods are of hexagonal wurtzite structure. The average crystallite size calculated from Scherrer's relation was found to be 40?nm. The effects of catalyst loading, pH value, and initial concentration of methyl orange on the photocatalytic degradation efficiency using ZnO nanorods as photocatalyst were discussed. The results revealed that ZnO nanorods with a diameter of 50?nm showed the highest photocatalytic activity at a surface density of 0.2?g?dm^?3.     

Fe/TiO2/ACF三元复合光催化材料联合脉冲放电降解甲基橙

采用溶胶-凝胶法制备了Fe/TiO₂/ACF三元复合光催化材料,将其投入到脉冲放电水处理反应器中降解甲基橙,考察该材料的光催化性能,以及它与脉冲放电的联合降解过程中操作因素的影响. 结果表明,Fe/TiO₂/ACF三元复合光催化材料与脉冲放电产生协同作用,大大提高了对甲基橙的去除率. 甲基橙的去除率与掺铁量〔以摩尔分数计〕、煅烧温度、溶液电导率和pH有关. 当掺铁量为0.07%,煅烧温度为900 ℃时,降解效果最佳;当溶液pH为6,电导率为300 μS/cm时,对Fe/TiO₂/ACF与脉冲放电的联合降解效果有利.      

The usability of oxidative stress and detoxification biomarkers in Gammarus pulex for ecological risk assessment of textile dye methyl orange

The present study was undertaken to determine the toxicity of the methyl orange by using the changes of some antioxidant and detoxification enzyme activities in Gammarus pulex. Lethal Concentration (LC) value of Methyl Orange (MO) was determined. Three sublethal doses of MO (1/4; 1/8 and 1/16 of LC value) were exposed to G. pulex for 24 and 96?h. Superoxide dismutase (SOD), Catalase (CAT), Glutathione peroxidase (GSH-P_X), Cytochrome p450 (CYP1A1), Glutathione S-transferase (GST) activities as well as Glutathione (GSH) and Malondialdehyde (MDA) levels were determined by using The enzyme-linked immunosorbent assay (ELISA) kit. The CAT and CYP1A1 activities were decreased in all the groups exposed to different doses of MO. GST activity and GSH, MDA levels were increased all the groups exposed to different doses of MO. The GSH-P_X activities were changed in all the groups. MO affected SOD activity at different levels and in different concentrations. In our study, it has been found that exposure duration didn’t significantly affect the biochemical biomarkers except for GST and GSH. In conclusion, alterations in antioxidant and detoxification enzymes and lipid peroxidation may potentially be used as sensitive biomarkers for risk assessment of dyes in the environment and may contribute to the establishment of discharge regulations.     

纳米氧化锌的制备及其光催化活性研究

以硫酸锌和尿素为原料,采用均相沉淀法制备纳米ZnO颗粒,并用TEM,IR,TGA,XRD等测试手段对其进行了表征。以紫外灯为光源,以纳米ZnO为光催化剂,氧化水溶液中的甲基橙。研究了催化剂的用量、光照时间、空气流量、光源性质对甲基橙降解的影响及ZnO粉体掺杂Ag^ 对其活性的影响。实验结果表明,掺杂Ag^ 后的纳米ZnO光催化效能大大提高。     

Differential activity of non-fluorinated and fluorinated analogues of the European corn borer pheromone

Summary.  The differing antagonist activity of (Z)-13-hexadecen-2-one (Z11 – 14 :MK, 1) and its 1,1,1-trifluoro derivative (Z11 –14 :TFMK, 2), two closely related analogues of the European corn borer pheromone Ostrinia nubilalis (Z strain), and their rationale is reported. Both chemicals exhibited some electrophysiological activity, and topical application of 10 pg of pheromone analogue on male antennae was sufficient to induce significantly lower depolarization responses to the pheromone versus untreated insects. In a wind tunnel, the number of European corn borer males attracted to sources containing mixtures of 1 + pheromone in ratios ≥ 1 :1 was significantly lower than the number attracted to a source containing pheromone alone. Source contact behaviour was dramatically impaired when the 1 + pheromone blend reached a ratio of 10 :1, in which only 2% of males displayed source contact in the presence of antagonist. When compound 1 was present at the source, males usually flew upwind with occasional downwind reversals; when compound 2 was present at the lure, males performed wider crosswind reversals, with little progress toward the source. In the field, traps baited with mixtures of both compounds with the pheromone in ratios of 5 :1 and 10 :1 elicited a significantly decreased number of male catches. In esterase inhibition assays, compound 2 was a potent inhibitor (IC₅₀ = 70 nM), whereas the non-fluorinated compound 1 was not. The different activity of both compounds is presumed to be due to different mechanisms of action; considerations for using methyl ketone analogues as new behavioural antagonists of the pheromone are outlined.     

富马酸单甲酯抑制球形棕囊藻生长的研究

研究了富马酸单甲酯对球形棕囊藻赤潮生物的抑制作用。结果表明:富马酸单甲酯可以有效延长藻细胞的生长适应期,降低生长量,缩短生长稳定期和诱导藻体细胞自溶。同时,运用量子化学原理从理论上论证了富马酸单甲酯分子控制赤潮藻类生长的作用机理。