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941.
针对黄磷生产尾气具有强化学活性和腐蚀性的特点,选择了TDX-01型碳分子筛色谱柱,采用气相色谱法测定黄磷尾气中的CO2。实验结果表明:黄磷尾气中高浓度的CO2用TCD检测器检测,CO2体积分数在0.1%~10%时,检测下限可达到0.05%,方法的平均回收率为93.6%~104.1%,相对标准偏差为2.1%~3.2%;净化后黄磷尾气中的微量CO2经Ni催化甲烷化转化后用FID检测器测定,CO2体积分数在1.0×10-7~1.0×10-4时,方法的检测下限可达到5.0×10-8,相对标准偏差为1.63%。 相似文献
942.
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944.
Uptake of polycyclic aromatic hydrocarbons by Trifolium pretense L. from water in the presence of a nonionic surfactant 总被引:1,自引:0,他引:1
A greenhouse study examined plant uptake of phenanthrene and pyrene, as representatives of polycyclic aromatic hydrocarbons (PAHs), from an aqueous solution containing a nonionic surfactant Tween 80. The uptake was conducted with 1.0 mg l(-1) phenanthrene and 0.12 mg l(-1) pyrene under a wide range of Tween 80 concentrations (0-105.6 mg l(-1)). Tween 80 at the test concentrations did not show any apparent phytotoxity toward the growth of red clover (Trifolium pretense L.). At concentrations generally lower than 13.2 mg l(-1), Tween 80 enhanced the plant uptake based on the concentrations and PCFs (plant concentration factors) of these two PAHs. When present at higher concentrations, Tween 80 inhibited the uptake of both PAH compounds by the tested plant. The maximal plant uptake was observed at 6.6 mg l(-1) Tween 80, in which PAH concentrations and PCFs were 18-115% higher than those in Tween 80-free controls. The total mass removal (off-take) of phenanthrene and pyrene by root or shoot increased initially and decreased thereafter with the increase in Tween 80 concentrations. Although shoot biomass was evidently larger than root, the off-take was much higher in root than shoot because of the larger root concentrations of these chemicals. Results from this study show promises for the potential efficacy of enhanced phytoremediation in PAH contaminated sites using surfactant amendment. 相似文献
945.
946.
Distribution characteristics of nonylphenol in Jiaozhou Bay of Qingdao and its adjacent rivers 总被引:6,自引:0,他引:6
Nonylphenol (NP) is an endocrine disruptor and causes harmful effects including feminization and carcinogenesis to various organisms. Consequently, its contamination in natural waters has received wide concerns. This study aims to investigate the seasonal variation and contamination level of nonylphenol in Jiaozhou Bay of Qingdao and its adjacent rivers. A total of 10 phenolic compounds including alkylphenol, chlorophenol and bisphenol A were measured in water, suspended solids and sediments in winter (January), spring (April) and summer (July) of 2005. The results showed that nonylphenol accounted for the majority of phenolic compounds and that its concentrations in Jiaozhou Bay ranged between 20.2-269 ng l(-1), 17.1-77.5 ng l(-1) and 3.6-299 ng g(-1)dw in surface water, suspended solids and surface sediment, respectively. There existed a significant correlation between nonylphenol in water and in suspended solids. The concentration of nonylphenol in water varied with seasons and generally showed a decreasing order of July>April>January. The concentrations of nonylphenol in the adjacent rivers were much higher with the maximum of 28600 ng l(-1) in surface water. The spatial distribution of nonylphenol in Jiaozhou Bay was influenced by freshwater discharge from the adjacent rivers as well as current circulation system within the bay. The pollution level of nonylphenol in Jiaozhou Bay was comparable to other highly polluted areas of the world and its possible effects on local organisms were discussed. 相似文献
947.
Aerobic granulation for 2,4-dichlorophenol biodegradation in a sequencing batch reactor 总被引:4,自引:0,他引:4
Development of aerobic granules for the biological degradation of 2,4-dichlorophenol (2,4-DCP) in a sequencing batch reactor was reported. A key strategy was involving the addition of glucose as a co-substrate and step increase in influent 2,4-DCP concentration. After operation of 39d, stable granules with a diameter range of 1-2mm and a clearly defined shape and appearance were obtained. After granulation, the effluent 2,4-DCP and chemical oxygen demand concentrations were 4.8mgl(-1) and 41mgl(-1), with high removal efficiencies of 94% and 95%, respectively. Specific 2,4-DCP biodegradation rates in the granules followed the Haldane model for substrate inhibition, and peaked at 39.6mg2,4-DCPg(-1)VSS(-1)h(-1) at a 2,4-DCP concentration of 105mgl(-1). Efficient degradation of 2,4-DCP by the aerobic granules suggests their potential application in the treatment of industrial wastewater containing chlorophenols and other inhibitory chemicals. 相似文献
948.
<正>强烈的太阳风暴并非地震与海啸等自然灾害的主要诱因,但它对航天、通信、电力等人类的高科技活动却会造成严重影响。美国国家科学院和美国宇航局2010年初郑重预警了2012—2014年太阳风暴将带来的影响。科学家们担忧,太阳的这一次猛然"苏醒",也 相似文献
949.
谈露天煤矿的安全隐患与防范措施 总被引:1,自引:0,他引:1
"安全为天、安全为本"是生产、生活中永恒的主题。无论从事何种生产经营活动,都必须把安全作为一项基础工作来抓,处处体现"安全第一、预防为主、综合治理"的安全生产方针。 相似文献
950.
J. Bai K. R. Li D. Y. Liu J. Zhang H. F. Zhang G. S. Liu J. L. Li Z. Y. Li D. M. Gao 《Water, Air, & Soil Pollution: Focus》2007,7(6):673-681
The distribution patterns and factors affecting uptake rates and turnover times of dissolved inorganic nutrients by heterotrophic
bacterioplankton (HB) in Jiaozhou Bay were studied based on in situ surveys and laboratory culturing. The uptake rates of
dissolved inorganic phosphorus (DIP) and dissolved inorganic nitrogen (DIN) by HB are limited by the temperature of the water
and the concentration of dissolved organic carbon. The turnover times of DIP and DIN by HB are regulated by the concentrations
of the nutrients and the numbers of HB, which show significant spatiotemporal variability in Jiaozhou Bay. HB may aggravate
the P-limitation of phytoplankton by competing for phosphorus in summer in Jiaozhou Bay. HB play an important role in the
biogeochemical cycling of nutrients and may increase the N:P ratio and the accumulation of DIN, thereby accelerating the imbalance
of the N:P ratio in Jiaozhou Bay. 相似文献