Iridodial: a powerful attractant for the green lacewing, Chrysopa septempunctata (Neuroptera: Chrysopidae)

The lacewing Chrysopa septempunctata Wesmael is an important, common predator of several insects in China, Japan, Russia, and many parts of Europe. Our field trapping experiments in northeast China showed that males of this green lacewing are strongly attracted to the lacewing pheromone of Chrysopa oculata Say, (1R,2S,5R,8R)-iridodial. The induced plant volatile, methyl salicylate, was unattractive to C. septempunctata by itself at the concentration tested, but synergistic when combined with iridodial where the lacewing population was high. (1R,4aS,7S,7aR)-Nepetalactol and (4aS,7S,7aR)-nepetalactone (aphid sex pheromone components) caught significantly more males of C. septempunctata than did blank control traps, but were inferior to iridodial dispensers, which remained strongly attractive to C. septempunctata males for at least 2.5 months. These results indicate that (1R,2S,5R,8R)-iridodial is a powerful attractant for C. septempunctata, and may have great potential for enhanced biological control of garden, agricultural, and forest insect pests.     

The partitioning and modelling of pesticide parathion in a surfactant-assisted soil-washing system

Soil sorption of organic pollutants has long been a problematic in the soil washing process because of its durability and low water solubility. This paper discussed the soil washing phenomena over a wide range of parathion concentrations and several soil samples at various fractions of organic content (foc) levels. When parathion dosage is set below the water solubility, washing performance is stable for surfactant concentrations above critical micelle concentration (cmc) and it is observed that more than 90% of parathion can be washed out when dosage is five times lower than the solubility limit. However, such trends change when non-aqueous phase liquids (NAPL) is present in the system. Parathion extraction depends very much on the surfactant dosage but is not affected by the levels of foc in the system. In between the extreme parathion dosage, a two-stage pattern is observed in these boundary regions. Washing performance is first increased with additional surfactant, but the increase slows down gradually since the sorption sites are believed to be saturated by the huge amount of surfactant in the system. A mathematical model has included foc to demonstrate such behavior and this can be used as a prediction for extraction.     

Effects of metsulfuron-methyl on the microbial population and enzyme activities in wheat rhizosphere soil

The effects of metsulfuron-methyl, a sulfonylurea herbicide, on the wheat soil microorganisms were evaluated by the methods of microbial inoculation culture, and the activities of three enzymes were measured using the colorimetric method. The tolerant microorganisms that can resist 500 microg x g(-1) metsulfuron-methyl in the counting culture medium were studied specially. Metsulfuron-methyl distinctly inhibited the common aerobic heterotriphic bacteria, but the effects on common fungi and common actinomycete were not evident. In the meantime, the number of tolerant fungi increased greatly in the rhizosphere after the application of metsulfuron-methyl in contrast to the significant decrease of the amount of tolerant actinomycete. It indicates that fungi might turn into the dominant microbial type and actinomycete is the sensitive factor in the soil polluted by sulfonylurea residues. The population of aromatic compounds-decomposing bacteria, aerobic azotobacter, and nitrite bacteria all increased in the earlier period, but the aerobic azotobacter decreased rapidly in number 30 days later, and the amount of nitrite bacteria also showed a temporary decrease with time 15 days later. However, the denitrifying bacteria just began to increase significantly after the crops had grown for 50 days. The amount of sulfur-oxidizing bacteria gradually decreased with the growth of crops, and so were the sulfate-reducing bacteria after metsulfuron-methyl application. To all types of microorganisms, there were more microbes in rhizosphere samples than those in nonrhizosphere except aerobic azotobacter. It means the growth of wheat root system can stimulate the growth of most microorganisms. The activities of hydrogen peroxidase and polyphenol oxidase in soil samples after metsulfuron-methyl application were notably lower than those in the control, and the difference of the activities between the samples of rhizosphere and nonrhizosphere was evident. On the contrary, the activity of dehydrogenase was not inhibited by the application of metsulfuron-methyl, and the rhizosphere effect was not obvious either.     

剑湖流域土壤/沉积物重金属分布特征、来源解析及生态风险

以剑湖流域为研究对象,通过系统采集流域内陆地土壤、河流和湖泊沉积物样品,利用电感耦合等离子体发射光谱仪(ICP-OES)测定72个采样点镉(Cd)、铬(Cr)、铜(Cu)、铅(Pb)、钒(V)和锌(Zn)等6种重金属含量,分析流域重金属分布特征,利用单因子污染指数法和内梅罗综合污染指数法、地累积指数法评估其污染程度,利...     

炼化企业实施职业健康监护项目与周期研究

从现行规范存在的问题入手,提出了确定炼化企业职业健康监护项目与周期的建议,旨在科学合理地指导炼化企业职业健康监护工作的运行操作。     

华东电网超超临界CDM项目CO2减排量研究

介绍了燃煤电厂超超临界CDM类型项目CO2减排量的理论计算过程，说明各参数的取值方法，并结合华东电网超超临界CDM项目案例给予演示，最后就减排问题对CDM项目的开发提出了建议。     

Codisposal of municipal refuse, sewage sludge and marine dredgings for methane production

As marine disposal of sewage sludge and dredged sediments may impose serious adverse effects to marine ecosystems, landfilling seems to be the most feasible method for the final disposal of these wastes. A batch experiment was conducted to study waste degradation and gas production after sewage sludge and marine dredgings were mixed with municipal refuse at 13 different ratios for 36 days. The addition of sludge and dredgings to municipal refuse enhanced gas production, compared with the degradation of refuse or sludge alone. A proper mixing ratio of wastes can also shorten the time to reach the final phase of anaerobiosis. The highest gas production was obtained from the ratio of 75-20-5 (refuse-sludge-dredgings) (wet weight basis). Its average daily gas production rate was 1.42 l kg(-1) waste mixture; methane content was 68.3%. The results indicated that codisposal of the three wastes would be beneficial for energy recovery from landfill gas.     

城市交通环境空气质量评价的灰色层次方法

本文分析了城市交通环境空气影响因素,提出了一套评价指标体系,并应用灰色理论和层次分析法建立了环境空气质量评价的灰色层次评估法。     

Effect of soil properties on saturated and unsaturated virus transport through columns

Viruses from contaminant sources can be transported through porous media to drinking water wells. The objective of this study was to investigate inactivation and sorption of viruses during saturated and unsaturated transport in different soils. Bacteriophages phiX174 and MS-2, and Br- tracer in a phosphate-buffered saline solution were introduced into saturated and unsaturated soil columns as a step function under constant flow rate and hydraulic conditions. Results showed that significantly greater virus removal occurred in the unsaturated columns than in the saturated columns in the two soils containing high metal oxides content. However, the increase in virus retention under unsaturated conditions was not significant in two other soils having high phosphorus and calcium contents and high pH, and in another soil with high organic matter content. The results imply that the extent of water content effect on inactivation and sorption of viruses can range from significant to minimal depending on the properties of the transport medium. We found that the presence of in situ metal oxides was a significant factor responsible for virus sorption and inactivation. Therefore, soils with high metal oxides content may have the potential to be used as hydrological barriers in preventing microbial contamination in the subsurface environments. We also found that the water content effect on virus removal and inactivation strongly depended on solid properties of the testing medium.     

Enzymatic oxidative transformation of chlorophenol mixtures

Chlorinated phenols are major industrial and agricultural xenobiotics that pollute soil and ground water. It has been shown that laccases catalyze the oxidative coupling of phenolic compounds. Therefore, the transformation of one or a mixture of several chlorinated phenols by a laccase from the fungus Trametes villosa was studied. Generally, if more than one phenol was added, the transformation of chlorinated phenols decreased, and if the concentration of the laccase was increased, the transformation of the phenols was enhanced. There were exceptions to these observations: for instance, the transformation of 0.1 mM 4-chlorophenol incubated with 1 mM 2,4-dichlorophenol in buffered salt solutions was not enhanced if the concentration of the laccase was increased from 2 to 20 DMP units/mL. The reason for the reduced transformation of chlorinated phenols in the presence of additional phenols is still unknown. However, in spite of some limitations, the application of laccase to decontaminate wastewater polluted with chlorinated phenols appears feasible.