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一株苯酚降解菌的分离和鉴定 总被引:42,自引:0,他引:42
:从工业废水中分离到一株高效降解苯酚的菌株PHEA 2 ,它能够在以苯酚为单一碳源和能源的无机培养基上生长 ,其最高苯酚降解率为 394nmol/ (mg·min) .经Biolog细菌自动鉴定仪鉴定 ,该菌株为醋酸钙不动杆菌 (Acinetobactercalcoaceti cus) .采用PCR扩增获得的该菌 16SrDNA片段 ,核苷酸序列分析结果表明 ,该菌株的 16SrDNA的核苷酸序列与醋酸钙不动杆菌同源性为 98% .在细菌系统发育分类学上 ,PHEA 2归属变形细菌γ亚类、不动杆菌属、醋酸钙不动杆菌 . 相似文献
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半导体生产排放的废气和废水中砷、磷、硫的分析方法研究 总被引:2,自引:0,他引:2
研究了一种快速、灵敏、可靠的高温氢还原-气相色谱分析方法[1-2],并自行设计了高温还原系统(还原炉、六通阀等),测定半导体生产排放废气和废水中的砷、磷、硫及其化合物,样品不需预处理,使气相色谱仪能直接测定固、液、气相样品中砷、磷、硫及其化合物的含量。砷、磷、硫的检测限分别为0.01mg/L、0.003mg/L、0.02mg/L;相对标准偏差分别为6.2%、8.6%和0.3%,与经典方法进行对比,结果基本一致。从分析方法的误差统计角度,也说明该方法准确、可靠。 相似文献
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Paul V Bolstad Wayne T Swank 《Journal of the American Water Resources Association》1997,33(3):519-533
ABSTRACT: Water quality variables were sampled over 109 weeks along Coweeta Creek, a fifth-order stream located in the Appalachian mountains of western North Carolina. The purpose of this study was to observe any changes in water quality, over a range of flow conditions, with concomitant downstream changes in the mix of landuses. Variables sampled include pH, HCO32?, conductivity, NO3??-N, NH4+-N, PO43?-P, C1?-, Na, K, Ca2+, Mg2+, SO42?, 5iO2, turbidity, temperature, dissolved oxygen, total and fecal coliform, and focal streptococcus. Landcover/landuse was interpreted from 1:20,000 aerial photographs and entered in a GIS, along with information on total and paved road length, building location and density, catchment boundaries, hydrography, and slope. Linear regressions were performed to relate basin and near-stream landscape variables to water quality. Consistent, cumulative, downstream changes in water quality variables were observed along Coweeta Creek, concomitant with downstream, human-caused changes in landuse. Furthermore, larger downstream changes in water quality variables were observed during stormflow when compared to baseflow, suggesting cumulative impacts due to landscape alteration under study conditions were much greater during storm events. Although most water quality regulations, legislation, and sampling are promulgated for baseflow conditions, this work indicates they should also consider the cumulative impacts of physical, chemical, and biological water quality during stormflow. 相似文献
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基于C/S与B/S混合模式的大气污染监测系统设计 总被引:1,自引:0,他引:1
以C/S与B/S混合模式为基础的大气监测系统、既能充分发挥网络资源的便捷化,实现企业监测数据与管理系统的快速链接,又充分利用C/S模式的安全性能,以保证系统的安全性。因而此系统是当前的一种较新型的,功能较为强大的网络监测系统。 相似文献
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本文为了增加对突发事件的科学认识,提升应急管理的能力水平,首先对突发事件和应急管理的内在机理进行剖析。通过分阶段、划层次地构建"4L-5S"机理分析模型,将二者划归为统一体系,以理清其逻辑内涵;然后,为顺应时代发展特征,满足应急管理的更高要求,实现应急管理工作从非常态协同应对转为常态化职能管理,对现代应急管理体制加以总体设计。从而,突发事件机理体系设计使得我国的突发事件机理研究逐渐过渡至具有阶段性和层次性,现代应急管理体制设计使得我国应急管理整合出具备现代思维理念的逻辑框架。 相似文献
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Estimating abundance without recaptures of marked pallid sturgeon in the Mississippi River 下载免费PDF全文
Nicholas A. Friedenberg Jan Jeffrey Hoover Krista Boysen K. Jack Killgore 《Conservation biology》2018,32(2):457-465
Abundance estimates are essential for assessing the viability of populations and the risks posed by alternative management actions. An effort to estimate abundance via a repeated mark‐recapture experiment may fail to recapture marked individuals. We devised a method for obtaining lower bounds on abundance in the absence of recaptures for both panmictic and spatially structured populations. The method assumes few enough recaptures were expected to be missed by random chance. The upper Bayesian credible limit on expected recaptures allows probabilistic statements about the minimum number of individuals present in the population. We applied this method to data from a 12‐year survey of pallid sturgeon (Scaphirhynchus albus) in the lower and middle Mississippi River (U.S.A.). None of the 241 individuals marked was recaptured in the survey. After accounting for survival and movement, our model‐averaged estimate of the total abundance of pallid sturgeon ≥3 years old in the study area had a 1%, 5%, or 25% chance of being <4,600, 7,000, or 15,000, respectively. When we assumed fish were distributed in proportion to survey catch per unit effort, the farthest downstream reach in the survey hosted at least 4.5–15 fish per river kilometer (rkm), whereas the remainder of the reaches in the lower and middle Mississippi River hosted at least 2.6–8.5 fish/rkm for all model variations examined. The lower Mississippi River had an average density of pallid sturgeon ≥3 years old of at least 3.0–9.8 fish/rkm. The choice of Bayesian prior was the largest source of uncertainty we considered but did not alter the order of magnitude of lower bounds. Nil‐recapture estimates of abundance are highly uncertain and require careful communication but can deliver insights from experiments that might otherwise be considered a failure. 相似文献
30.
蠡河底泥中反硝化复合菌群富集及菌群结构研究 总被引:2,自引:2,他引:0
从无锡市滨湖区蠡河底泥中富集培养反硝化复合菌群,研究其在不同富集培养阶段TN、NO-3-N、NO-2-N、NH+4-N和COD动态变化,分析反硝化过程中气体释放总量、释放速率和成分,通过构建全长16S r DNA克隆文库研究其菌落结构.结果表明,反硝化复合菌群富集在阶段4时脱氮效果最佳,仅在9 h内,330 mg·L-1的TN负荷下,TN去除率达90.9%,NO-3-N去除率达100%,中间产物NO-2-N和NH+4-N积累量最少,分别为3.39 mg·L-1和16.64 mg·L-1,COD去除率达85%;释放气体260m L,气体主要成分为N2,同时还有少量的CH4和CO2等.富集培养反硝化复合菌群细菌属于Pseudomonadaceae科和Rhodocyclaceae科,为Proteobacteria门,OUT丰度分别为57.8%和31.6%,Pseudomonadaceae科是优势类群. 相似文献