排序方式: 共有16条查询结果,搜索用时 15 毫秒
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K. M. S. Sundaram A. Sundaram 《Journal of environmental science and health. Part. B》2013,48(5):453-473
Abstract Spray deposit patterns were measured on aluminum coils and live balsam fir needles at different canopy heights, following aerial application of mexacarbate (4‐dimethylamino‐3,5‐xylyl N‐methylcarbamate) over a conifer forest in New Brunswick. Droplet size spectra of the spray cloud were determined on cylindrical Kromekote® cards placed at the corresponding crown heights. Ground deposits were collected on cylindrical Kromekote cards, aluminum coils and natural balsam fir foliage placed In forest clearings and under different types of vegetation. Canopy deposits decreased progressively from the top to the bottom level of the tree crown. This trend was observed on aluminum coils, live fir foliage, and Kromekote cards. Droplet size spectra were similar at all sampling heights of the tree crown, and were comparable to those obtained on the ground cards placed in the forest clearings. Deposits of mexacarbate obtained on ground samplers on the open forest floor were markedly lower than those found at the top canopy but were similar to those at the mid or bottom canopy level. Droplet size spectra and mexacarbate deposits obtained on samplers placed under different types of forest vegetation indicated a selective filtration of the large droplets present in the spray cloud by plant canopies. 相似文献
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L. Pereira C. Bastos T. Tzanov A. Cavaco-Paulo G. M. Guebitz 《Environmental Chemistry Letters》2005,3(2):66-69
A new strain of Trametes hirsuta was found to oxidize various cotton flavonoids. Here we show that laccases of this organism were responsible for oxidation
of the flavonoids morin, luteolin, rutin and quercetin. Out of two laccases produced by T. hirsuta (60.7 and 51.0 kDa) the more prominent 60.7 kDa laccase was purified and showed K
m and k
cat values of 75.5, 20.9 and 49.4 μM and 72.5, 96.3 and 32.7 s−1, hours on ABTS, syringaldazide and DMP, respectively. Pretreatment of cotton with the T. hirsuta laccase resulted in a whiteness increase of 8.5%. 相似文献
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微电解—SBR组合工艺处理漂染废水 总被引:4,自引:0,他引:4
采用微电解-SBR组合工艺对漂染废水进行了处理研究。结果表明,以微电解作预处理,使 漂染废水的可生化性BOD5/COD比值为0.22-0.26提高到0.35-0.57。再经SBR法和炉渣吸附法处理后,各项水质指标均达GB8978-88《污水综合排放标准》中纺织印染工业的一级标准。 相似文献
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Ronnen Levinson Paul Berdahl Asmeret Asefaw Berhe Hashem Akbari 《Atmospheric environment (Oxford, England : 1994)》2005,39(40):7807-7824
A roof with high solar reflectance and high thermal emittance (e.g., a white roof) stays cool in the sun, reducing cooling power demand in a conditioned building and increasing summertime comfort in an unconditioned building. The high initial solar reflectance of a white membrane roof (circa 0.8) can be lowered by deposition of soot, dust, and/or biomass (e.g., fungi or algae) to about 0.6; degraded solar reflectances range from 0.3 to 0.8, depending on exposure. We investigate the effects of soiling and cleaning on the solar spectral reflectances and solar absorptances of 15 initially white or light-gray polyvinyl chloride membrane samples taken from roofs across the United States. Black carbon and organic carbon were the two identifiable strongly absorbing contaminants on the membranes. Wiping was effective at removing black carbon, and less so at removing organic carbon. Rinsing and/or washing removed nearly all of the remaining soil layer, with the exception of (a) thin layers of organic carbon and (b) isolated dark spots of biomass. Bleach was required to clear these last two features. At the most soiled location on each membrane, the ratio of solar reflectance to unsoiled solar reflectance (a measure of cleanliness) ranged from 0.41 to 0.89 for the soiled samples; 0.53 to 0.95 for the wiped samples; 0.74 to 0.98 for the rinsed samples; 0.79 to 1.00 for the washed samples; and 0.94 to 1.02 for the bleached samples. However, the influences of membrane soiling and cleaning on roof heat gain are better gauged by fractional variations in solar absorptance. Solar absorptance ratios (indicating solar heat gain relative to that of an unsoiled membrane) ranged from 1.4 to 3.5 for the soiled samples; 1.1 to 3.1 for the wiped samples; 1.0 to 2.0 for the rinsed samples; 1.0 to 1.9 for the washed samples; and 0.9 to 1.3 for the bleached samples. 相似文献
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The Bothnian Bay, which is the northernmost part of the Gulf of Bothnia in Northern Finland, is affected by effluents discharged from point sources such as the pulp and paper mills of Stora Enso Oyj Veitsiluoto Mill and Oy Metsä-Botnia Ab Kemi Mill at Kemi, and the Kemi municipal sewage plant, as well as the River Kemijoki. In this paper we discuss, how modernisation of the wastewater treatment plant at the mills, and process investments in the Best Available Techniques (BAT) for effluent treatment, have decreased the effluent discharges of biological oxygen demand (BOD), chemical oxygen demand (COD), total phosphorus (Tot-P), total nitrogen (TOT-N), total suspended solids (TSS) and adsorbable organically bound halogens (AOX) from the mills since 1988. One specific aim of the study was to determine the EOX (Extractable Organically Bound Halogens) concentrations in bottom sediment of the Bothnian Bay in order to assess whether the EOX concentrations reflect the reduction in discharges of chlorinated compounds. According to the monitoring program carried out every third year between 1997–2006, the decreasing trend in EOX concentrations in the top 2 cm of the bottom sediment reflect the decrease in organochlorine discharges (AOX) from the mills. In 1997 the EOX concentrations in bottom sediment varied between 3–70 μg of Cl g?1 (dry weight), and in 2006 between 3.3–32 μg of Cl g?1 (dry weight). 相似文献
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蔗渣浆酶促漂白预处理对纤维形态性质和污染物发生的影响 总被引:1,自引:0,他引:1
采用Pulpzyme HC木聚糖酶对蔗渣纸浆进行酶促漂白处理。试验结果表明,酶处理的最佳纸浆浓度为5%,处理时间为60min.酶用量为1.0IU/g。酶处理后纸浆的得率下降不多.强度略有升高,但纸浆白度增加。试验结果还表明,酶处理对纸浆纤维不具有破坏性。对酶处理后纸浆的扫描电镜观察说明,随酶处理时间和酶用量的增加,蔗渣中木聚糖的溶出量加大。酶处理使木聚糖降解溶出,使木质素充分暴露出来,有利于后续漂白剂与之反应.同时可减少后续化学漂白剂的使用量,从而减少有毒氯化有机污染物的产生。随处理时间增长和酶用量增加,处理液中CODcr,和BOD5呈上升趋势。酶用量超过1.5IU/g后.BOD5增长较缓慢,表明酶的作用对纤维表面生物可降解成分的溶出较彻底。 相似文献