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601.
利用基因工程菌BL21处理有机磷混合农药废水的研究 总被引:1,自引:0,他引:1
研究了悬浮状态和固定化状态的基因工程菌BL21对有机磷混合农药废水的降解特性.工程菌能快速、高效地降解有机磷混合农药,其最适底物是对硫磷,而马拉硫磷不能被工程菌降解.不同农药降解速率的差别造成了不同有机磷农药的降解过程需要用不同的动力学模型来描述.比较固定化状态和悬浮状态的工程菌的降解效果可知,固定化工程菌的降解活性较后者明显降低,其比降解速率大约仅为后者的20%.考察固定化工程菌长期运行的效果,发现其降解活性保存良好,工程菌稳定性大大提高,未出现固定化细胞溶涨、破碎现象.固定化后,工程菌的比降解速率虽然比悬浮工程菌降低了,但固定化工程菌更适用于长期运行的废水处理系统. 相似文献
602.
Banas D Masson G Leglize L Usseglio-Polatera P Boyd CE 《Environmental pollution (Barking, Essex : 1987)》2008,152(3):679-685
Expansion of aquaculture has increased concern over its environmental impact. The composition of effluents from intensive aquaculture is well documented, but few data on extensive aquaculture are available. During 12 draining operations, 523 water samples were collected downstream from six extensively-managed fishponds in northeastern France. Study ponds had surface areas of 2-620 ha and were managed for production of Cyprinids and Percids. Concentrations of total suspended solids, total phosphorus, and Kjeldahl nitrogen in effluents from the ponds were greatest during the final stage of draining. Loads of phosphorus were higher than those reported for effluents of more intensive aquaculture ponds in the USA, but the source of the potential pollutants was catchments and sediment rather than feeds and fertilizer. It will be necessary to reduce the water drawdown rate during the fishing stage and possibly implement other best management practices to prevent the TSS concentration from exceeding 1 g/L. 相似文献
603.
厌氧分步生物反应器系统处理城市生活垃圾的试验研究 总被引:4,自引:2,他引:2
以生活垃圾中COD溶出量为研究参数,试验研究了厌氧分步生物反应器系统和渗滤液直接回灌填埋场中的有机物降解规律与产甲烷特征.结果表明:厌氧分步生物反应器系统可显著促进生活垃圾及渗滤液中有机污染物的降解,加速填埋垃圾稳定化,其COD溶出总量与填埋时间的对数呈极显著的线性相关性.厌氧分步生物反应器中产甲烷反应器的产气量占总产气量的80%,甲烷含量55%~69%,较适容积COD负荷为6.5~7.5g/(L·d). 相似文献
604.
Using the Yellow River, China, the study explores the problem of the use of COD and BOD5 as water quality management parameters in the presence of very high levels of suspended sediment (TSS) that characterize
this river. Although the amount of natural organic matter per unit of suspended sediment of the Yellow River is not high,
the very high concentration of mineral sediment in the Yellow River results in a large concentration of organic matter, which
artificially inflates the laboratory values of COD and, as a consequent, leads to greatly exaggerated reports of pollution
of the Yellow River. BOD5 can more accurately reflect the pollution of the Yellow River than COD; however, measured values of BOD under-report the
actual values due to settling of the sediment in the incubation chamber resulting in values that are 21.6--38.3% less than
the actual values. Therefore corrections are required for laboratory COD and BOD values so that the values are not artifacts
of the sediment regime. Our work provides new insight into this phenomenon and demonstrates how correction factors may be
determined and used with pollution data. Our work also suggests that the actual pollution levels of the Yellow River are probably
not as high as reported by monitoring agencies. 相似文献
605.
Griffith JF Aumand LA Lee IM McGee CD Othman LL Ritter KJ Walker KO Weisberg SB 《Environmental monitoring and assessment》2006,117(1-3):335-344
During the summers of 2002 and 2004, in-stream integrated flow and concentration measurements for the total dissolved solids
in the Cheyenne River, South Dakota, USA was conducted in order to compare the obtained actual field measurements with the
predictions values made by the Bureau of Reclamation in the Environmental Impact Statement. In comparison to the actual field
measurements conducted in this study, The Bureau of Reclamation extension of a small database used in the analysis for the
impact of operations at the Angostura Unit over the past 50 years and into the future to predict the annual total dissolved
solid loadings doesn't represent the actual loading values and various conditions in the study area. Additional integrated
flow and concentration sampling is required to characterize the impact of the current Angostura Dam operations and Angostura
Irrigation District return flows on the Cheyenne River in different seasons of the year. 相似文献
606.
Aerosol samples for dry deposition and total suspend particulates (TSP) were collected from August to November of 2003 in central Taiwan. Ion chromatography was used to analyze the related water-soluble ionic species (Cl−, NO3
−, SO4
2−, Na+, NH4
+, K+, Mg2+ and Ca2+). The results obtained in this study indicated that the ambient air particulate mass concentrations in the daytime period (averaged 975.4 μg m−3) were higher than the nighttime period (averaged 542.1 μg m−3). And the daytime dry deposition fluxes (averaged 58.12 μg m−2 sec−1) were about 2.2 times as that of nighttime dry deposition fluxes (averaged 26.54 μg m−2 sec−1) of the downward dry deposition. The average values downward and upward of dry deposition fluxes for the weekend period were almost higher than the weekday period for either daytime or nighttime period. Furthermore, the average daytime dry deposition fluxes (averaged 26.37 μg m−2 sec−1) were also about 2.3 times as that of nighttime dry deposition fluxes (averaged 11.52 μg m−2 sec−1). Moreover, the results also indicate that SO4
2− and Ca2+ have higher average composition for total suspended particulates in the daytime period while Ca2+, SO4
2−, and Na+ have the higher average composition for total suspends particulates in the nighttime period. 相似文献
607.
黄河中下游水体中多环芳烃的分布及来源 总被引:15,自引:5,他引:10
对小浪底至山东东明段黄河干、支流水、悬浮物和沉积物进行了采样分析.结果表明,干流水相∑15PAHs浓度范围为179~369ng/L,其中除焦巩桥外其它断面苯并(a)芘均超过国家饮用水标准;支流水相浓度均高于相应干流,尤其是富含低环PAHs的孟州一干渠对干流沉积相浓度有较大影响.与水相相比,悬浮、沉积相中PAHs检出种类较多,干流悬浮相∑13PAHs浓度范围为54~155μg/kg,且各环PAHs与悬浮相中TOC含量间存在一定正相关.干流沉积相∑13PAHs浓度范围为31~133μg/kg,其4、5、6环P 相似文献
608.
609.
610.
太湖水体中悬浮物研究 总被引:68,自引:2,他引:68
为了全面了解太湖水中悬浮物的物质组成、变化规律,选取了太湖站近10年来各测点的连续观测资料及2次定点观测资料,分析了太湖水体中悬浮物的无机和有机颗粒成份、时空分布、垂直变化、与风速、风向的关系以及与重要光
学参数的关系。研究结果表明:太湖悬浮物中有机物大概占30%;浓度大小的湖区分布大致是:湖心区>河口区、梅梁湖、贡湖、五里湖>东太湖;悬浮物浓度的季节变化是:湖心区冬季、春季>秋季>夏季,东太湖冬季>春季、夏季、秋季,其他湖区则没有明显季节变化;垂直分布是:深层>表层并且底泥悬浮的临界风速在5~6.5 m/s之间;悬浮物浓度的增加是引起湖水透明度降低和光学衰减系数增大的主要原因。 相似文献