饮用水在蓄贮过程中二次污染数学模拟与应用研究

对饮用水在贮存过程中二次污染的原因进行分析,定性定量地模拟研究了在静态条件下,饮用水在蓄贮过程中二次污染的水质空间变化规律。     

厌氧酸化+兼氧+好氧工艺处理印染废水小试实验

某印染厂废水处理系统拟使用厌氧酸化+兼氧+好氧工艺对其生化处理部分进行改造,为减少改造风险进行小试研究。研究中改变进水污染物浓度和水力停留时间等条件,考察了不同条件下的处理效果的异同,小试的研究表明厌氧酸化+兼氧+好氧工艺处理该印染厂废水具有较好的效果,其结果可为同类型废水处理参考和借鉴。     

有机蒙脱石填充PDMS膜分离水相有机物的渗透汽化研究

以乙醇、乙酸的水溶液为渗透汽化分离对象，将CTAB柱撑蒙脱石作为填充剂，制备了填充型PDMS(聚二甲基硅氧烷)膜，研究填充膜对乙醇／水及乙酸／水体系的渗透汽化分离，结果表明，蒙脱石的吸附特性及其层间柱撑通道可以明显改善PDMS膜的选择性和通量，填充膜分离乙醇或乙酸的分离效果明显不同，对可能存在的渗透汽化分离机理进行了探讨。     

野化培训大熊猫在特定时期采食半枯竹的原因分析

对首次发现的一只野化培训大熊猫“祥祥”采食半枯竹的现象及原因进行研究.作者用4只圈养大熊猫为对照进行试验,从行为观察、营养成分及适口因子、环境气候条件等方面进行了研究.研究发现,圈养大熊猫中也存在采食半枯竹的现象,而且在采食的时间段上和祥祥一致;相对于新鲜竹子,半枯竹中葡萄糖含量有所增加,单宁含量明显降低,并且具有特殊的香甜味,使在一定时期内的半枯竹营养增加,适口性得到改善,这是大熊猫在特定时期更愿意采食半枯竹而不采食新鲜竹子的重要原因;7~9月是全年温湿度最高月份,对引起半枯竹成分中适口因子的改变可能有诱发作用.图3表4参9     

Applicability of molecular connectivity indices to model toxicity of phenylthiocarboxylates on Photobacterium phosphoreum

Acute toxicity (15min-EC₅₀) of 22 phenylthio-carboxylates to Photobacterium phosphoreum is reported. A quantitative structure-activity relationship equation was established using molecular connectivity indices, and it was used to predict the toxicity of other phenylthiocarboxylates to Photobacterium phosphoreum successfully. This study is useful for us to estimate the toxicity behavior of phenylthio-carboxylates.     

Effects of pre-exposure to ultraviolet-B radiation on responses of tomato (Lycopersicon esculentum cv. New Yorker) to ozone in ambient and elevated carbon dioxide

Patterns of environmental change in the biosphere include concurrent and sequential combinations of increasing ultraviolet (UV-B) and ozone (O(3)) at increasing carbon dioxide (CO(2)) levels; long-term changes are resulting mainly from stratospheric O(3) depletion, greater tropospheric O(3) photochemical synthesis, and increasing CO(2) emissions. Effects of selected combinations were evaluated in tomato (Lycopersicon esculentum cv. New Yorker) seedlings using sequential exposures to enhanced UV-B radiation and O(3) in differential CO(2) concentrations. Ambient (7.2 kJ m(-2 )day(-1)) or enhanced (13.1 kJ m(-2) day(-1)) UV-B fluences and ambient (380 microl l(-1)) or elevated (600 microl l(-1)) CO(2) were imposed for 19 days before exposure to 3-day simulated O(3) episodes with peak concentrations of 0.00, 0.08, 0.16 or 0.24 microl l(-1) O(3) in ambient or elevated CO(2). CO(2) enrichment increased dry mass, leaf area, specific leaf weight, chlorophyll concentration and UV-absorbing compounds per unit leaf area. Exposure to enhanced UV-B increased leaf chlorophyll and UV-absorbing compounds but decreased leaf area and root/shoot ratio. O(3) exposure generally inhibited growth and leaf photosynthesis and did not affect UV-absorbing compounds. The highest dose of O(3) eliminated the stimulating effect of CO(2) enrichment after ambient UV-B pre-exposure on leaf photosynthesis. Pre-exposure to enhanced UV-B mitigated O(3) damage to leaf photosynthesis at elevated CO(2).     

Components and dispersion characteristics of organic and inorganic odorous gases in a large-scale dairy farm

The rapid development of large-scale livestock husbandry has caused serious air pollution problems (e.g., The Tuzuoqi demonstration farm belonging to the Yili Group. The farm is located in the suburb of Hohhot City in northern China). In this study, the gases in typical areas of a large-scale dairy farm were sampled and measured for volatile organic compounds (VOCs), hydrogen sulfide, and ammonia concentrations. Fifty-two species of VOCs were identified. The VOCs emitted from the cowshed mainly consisted of halogenated hydrocarbons (16,960 µg/m³), ketones (15,700 µg/m³), esters (9889 µg/m³), and sulfur compounds (3677 µg/m³). The VOCs from the oxidation pond were mainly composed of halogenated hydrocarbons (21,940 µg/m³) and ketones (3589 µg/m³). The VOCs from the solid–liquid separation tank comprised halogenated hydrocarbons (32,010 µg/m³), ketones (7169 µg/m³), and sulfur compounds (1003 µg/m³). The highest concentrations of ammonia and hydrogen sulfide were obtained from the milking parlor and solid–liquid separation tank, respectively. The ammonia concentration declined gradually due to the superposition of ammonia emitted from the cowshed and milking parlor. Analysis results of the influences of distance and meteorological factors on the dispersion of ammonia and hydrogen sulfide suggested that the dilution factors decreased with increasing distance from the emission source. Within distance ranges of 0–10 and 10–25 m, the concentration dilution factors were positively correlated with wind speed and temperature but negatively correlated with humidity and atmospheric pressure. The results of our work can provide a theoretical basis for the prevention and control of odorous gases in large-scale livestock farms.

Implications: Gases in typical areas of a large-scale dairy farm were sampled, and a total of 52 species of VOCs were identified. The highest concentrations of ketones, sulfur compounds, and esters were obtained at the cowshed (15,700, 3677, and 9889 µg/m³, respectively). Within the distance ranges of 0–10 and 10–25 m, the concentration dilution factors were positively correlated with wind speed and temperature.     

The effect of temperature on the rate of cyanide metabolism of two woody plants

The response of cyanide metabolism rates of two woody plants to changes in temperature is investigated. Detached leaves (1.0 g fresh weight) from weeping willow (Salix babylonica L.) and Chinese elder (Sambucus chinensis Lindl.) were kept in glass vessels with 100ml of aqueous solution spiked with potassium cyanide for a maximum of 28 h. Ten different temperatures were used ranging from 11 degrees C to 32 degrees C. The disappearance of aqueous cyanide was analyzed spectrophotometrically. The cyanide removal rate of Chinese elder was higher than that of weeping willow at all temperatures. The highest cyanide removal rate for Chinese elder was found at 30 degrees C with a value of 12.6 mg CN kg(-1) h(-1), whereas the highest value of the weeping willow was 9.72 mg CN kg(-1) h(-1) at 32 degrees C. The temperature coefficient values, Q10, which are the ratio of removal rates at a 10 degree difference, were determined for Chinese elder and weeping willow to 1.84 and 2.09, respectively, indicating that the cyanide removal rate of weeping willow was much more susceptible to changes in temperature than that of the Chinese elder. In conclusion, changes in temperature have a substantial influence on the removal rate of cyanide by plants.     

城市绿地降低空气中含菌量的生态效应研究

按照大气生物监测的方法和要求，选择了上海市区的交通干通。公园和居住区的主要类型的绿地，对绿地降低气挟菌数量的生态效应进行了初步研究，结果表明，绿地结构，植物种类配置和粉尘污染是影响绿地降低气挟菌数量效应的主要因素。     

Span80-Tween60/T154/煤油/H2SO4微乳液膜处理氨氮废水

研究了以Span80和Tween60为混合表面活性剂的微乳液膜的配方及其稳定性，通过Span80-Tween60/T154/煤油/H2SO4微乳液膜体系处理氨氮废水的研究，考察了表面活性剂的配比、T154的浓度、萃取时间、乳水比、外水相pH值、油相回用次数等因素对氨氮萃取率的影响。实验结果表明，当Span80和Tween60的质量比为4∶1，T154在煤油中的质量浓度为5％，萃取时间为15 min，乳水比为1∶14，外水相pH值为9时，氨氮一次性萃取率可到99.85％；该微乳液膜不仅稳定性好，对氨氮萃取率高，而且制乳、破乳容易，油相可重复使用。