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Reducing bioassay variability by identifying sources of variation and controlling important parameters in assay protocol was demonstrated in this study. The variability of a bioassay based on a luminescent bacterium was examined as an example. This assay involved the growth of cells, storage at a low temperature, activation, and exposure to a test sample, and the assay response was bioluminescence inhibition. After determining that measurement error was small and negligible, the total assay variability was decomposed in an initial variance components study into between-batch, between-vial, and between-tube variations. Results indicated that between-vial variations accounted for the majority of the total observed variability and that reducing this type of variation would be beneficial. Five parameters in the assay protocol were determined as factors that potentially affected assay variability significantly. A split-plot design was employed to investigate the effects of these factors and some of their interactions on the assay response. One of the five factors, i.e., activation temperature, turned out to have a significant effect. The variance components study was repeated with better control of activation temperature as well as other parameters. Results indicated that the total variability of the bioassay was reduced by approximately 85%. 相似文献
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深床过滤机理及其在水处理中的应用研究与进展 总被引:2,自引:0,他引:2
深床过滤既有过滤功能,又具生物处理作用,具有良好的应用前景;本文阐述了深床过滤的最新研究动向,深床过滤过程的数学模型的构建方法,国内外利用深床过滤技术处理微污染水源水、城市生活污水及污水深度处理的实验研究状况. 相似文献
585.
采用热脱附-气相色谱/质谱联用法对4辆处于静止状态下的车辆内部空气中挥发性有机物(VOCs)进行了研究,共定性检出了48种有机物,其中C6~C9之间的组分较多;并对VOCs的总浓度进行了定量,1#~4#车分别为1846、2289、1104和3146 μg/m^3;其中BTEX占VOCs总量的20%~30%;车内VOCs浓度与温度及车辆使用年限密切相关. 相似文献
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湿热法处理实现厨余垃圾饲料化的研究 总被引:9,自引:0,他引:9
探索了湿热法工艺处理厨余垃圾并将其饲料化的可行性.实验表明,湿热法处理可以在满足消毒杀菌的同时,降低厨余原料中的高油脂含量和高含盐量,调节营养成分,实现物化性状的均一.经湿热法处理后的厨余垃圾的饲用价值得到明显改善,可作为良好的饲料原料,同时可回收利用油脂.总之,湿热法工艺可实现厨余垃圾的无害化、减量化和资源化处理,对于消除环境污染、缓解我国饲料原料紧张及资源回收利用等方面有着显著的环境效益、社会效益和经济效益,具有重要的现实意义. 相似文献
587.
Effect of pH on phosphine production and the fate of phosphorus during anaerobic process with granular sludge 总被引:6,自引:0,他引:6
The effect of pH on phosphine formation during anaerobic cultivation of granular sludge was investigated. The sludge was taken from full-scale anaerobic reactors treating brewery wastewater. Acetate and phosphate were used as the carbon source and phosphorus source respectively. After 10 days cultivation in the dark, results showed that acidic conditions were more favorable for free phosphine production. At pH 5, the optimum concentration 86.42 ng PH3 m-3 of free phosphine was obtained. The level at pH 7 was reduced to 18.53 ng PH3 m-3, about 1/5 of the maximum. The maximum concentration of matrix-bound phosphine of 3.30 ng PH3 kg-1 wet sludge was achieved at pH 6. More than 83% of the total phosphine was matrix-bound phosphine, which accounted for 0.003-0.009 per thousand of the phosphate removal, while free phosphine comprised 0.00002-0.001 per thousand of the phosphate removal. Most of the phosphorus removal from solution was turned into chemical precipitation or was adsorbed by sludge. The mechanism of the phosphate reduction-step in the formation of phosphine production is still unknown. The promotion of phosphine formation by low pH is compatible with an acidic bio-corrosion mechanism of metal particles in the sludge or of metal phosphides which form phosphine at low pH. 相似文献
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