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651.
生物活性滤池中微生物的生长研究 总被引:7,自引:0,他引:7
研究了活性炭一石英砂双层滤料生物活性滤池的挂膜过程。结果表明,在生物活性滤池中,微生物的生长速度是不同的:异养细菌生长速度最快,亚硝化细菌次之,硝化细菌最慢,整个挂膜过程历时3个月。在生物活性滤池内,异养细菌、亚硝化细菌和硝化细菌等三大微生物类群之间无明显的竞争关系,在后两者之间表现为互生关系;而在各个类群内部成员之间则表现为对基质的竞争关系。 相似文献
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The anaerobic ammonium oxidation (anammox) process was successfully started up from conventional activated sludge using a hybrid bioreactor within 2 months. The average removal efficiencies of ammonia and nitrite were both over 80%, and the maximum total nitrogen removal rate of 1.85 kg N/(m3.day) was obtained on day 362 with the initial sludge concentration of 0.7 g mixed liquor suspended solids (MLSS)/L. Scanning electron microscope (SEM) observation of the granular sludge in the hybrid reactor clearly showed a high degree of compactness and cell sphericity, and the cell size was quite uniform. Transmission electron microscope photos showed that cells were round or oval, the cellular diameter was 0.6--1.0 μupm, and the percentage of the anammoxosome compartment was 51%--85% of the whole cell volume. Fluorescence in situ hybridization analysis (FISH) indicated that anammox bacteria became the dominant population in the community (accounting for more than 51% of total bacteria on day 250). Seven planctomycete 16S rRNA gene sequences were present in the 16S rRNA gene clone library generated from the biomass and affiliated to Candidatus Kuenenia stuttgartiensis and Candidatus Brocadia sp., a new anammox species. In addition, the average effluent suspended solid (MLSS) concentrations of outlets I (above the non-woven carrier) and II (below the non-woven carrier) were 0.0009 and 0.0035 g/L, respectively. This showed that the non-woven carrier could catch the biomass effectively, which increased biomass and improved the nitrogen removal rate in the reactor. 相似文献
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Xiaofeng Huang Chuan Wang Jianfei Peng Lingyan He Liming Cao Qiao Zhu Jie Cui Zhijun Wu Min Hu 《环境科学学报(英文版)》2017,29(1):342-351
Knowledge of particle number size distribution(PND) and new particle formation(NPF)events in Southern China is essential for mitigation strategies related to submicron particles and their effects on regional air quality,haze,and human health.In this study,seven field measurement campaigns were conducted from December 2013 to May 2015 using a scanning mobility particle sizer(SMPS) at four sites in Southern China,including three urban sites and one background site.Particles were measured in the size range of15-515 nm,and the median particle number concentrations(PNCs) were found to vary in the range of 0.3× 10~4-2.2 × 10~4 cn~(-3) at the urban sites and were approximately 0.2 × 10~4 cm~(-3) at the background site.The peak diameters at the different sites varied largely from 22 to 102 nm.The PNCs in the Aitken mode(25-100 nm) at the urban sites were up to 10 times higher than they were at the background site,indicating large primary emissions from traffic at the urban sites.The diurnal variations of PNCs were significantly influenced by both rush hour traffic at the urban sites and NPF events.The frequencies of NPF events at the different sites were0%-30%,with the highest frequency occurring at an urban site during autumn.With higher SO_2 concentrations and higher ambient temperatures being necessary,NPF at the urban site was found to be more influenced by atmospheric oxidizing capability,while NPF at the background site was limited by the condensation sink.This study provides a unique dataset of particle number and size information in various environments in Southern China,which can help understand the sources,formation,and the climate forcing of aerosols in this quickly developing region,as well as help constrain and validate NPF modeling. 相似文献
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Lei Wang 《环境科学学报(英文版)》2013,25(3):452-459
Microcystis aeruginosa was used to study the effect of KMnO4 pre-oxidation on algal removal through coagulation with polyaluminium chloride (PAC).KMnO4 pre-oxidation improved the coagulation efficiency of algal at a low dosage of PAC.The optimal KMnO4 feeding period was in the stationary growth phase of Microcystis aeruginosa.KMnO4 traumatized the algal cells and stimulated cellular release of organic matter,contributing to the pool of extra-cellular organic matter (EOM).KMnO4 also decomposed EOM,especially small molecular weight EOM.Lower concentrations of KMnO4,such as 2 mg/L,induced algae cells to produce moderate amounts of new EOM with molecular weights of 11,280,and 1500 kDa.These relatively large molecules combined easily with PAC,promoting coagulation and removal of algae.High concentrations of KMnO4 lysed algae cells and produced much high-molecular-weight EOM that did not enhance flocculation by PAC at lower dosages. 相似文献
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环境一号卫星CCD相机应用在陆地气溶胶的监测中,因缺少短波红外通道,使地表反射的去除变得异常困难.应用改进的暗目标法,利用辐射传输方程(6S)构建查找表,对CCD相机数据进行图像重采样和辐射定标处理,进而对查找表进行插值,获得气溶胶光学厚度(AOD)分布.通过AERONET地基数据的验证及与MODIS气溶胶产品的对比表明,环境一号卫星CCD相机对陆地气溶胶的监测结果在AOD较大(>0.2)时,精度与MODIS相近;在AOD较小(<0.2)时,结果欠理想. 相似文献
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针对太湖湖滨带,均匀布设49个点位,分别于2009年12月、2010年4、8月开展浮游植物及水质监测。结果显示,湖滨带浮游植物群落多样性整体较低,优势种从枯水期到丰水期呈"鱼腥藻-鱼腥藻-微囊藻"的演变趋势;西北部湖区(竺山湖、梅梁湾、西部沿岸)浮游植物密度明显高于东南部湖区(东部沿岸、东太湖、南部沿岸);湖滨带浮游植物群落结构与湖体相似,密度比湖体高1个数量级;RDA排序筛选出在显著水平上解释浮游植物分布的最小变量组合为TN、CODMn、SS、p H、SD,且方差分解指出TN是相对最重要的变量;当物种适合度为50%~100%时,与TN具有较好梯度响应关系的是四尾栅藻及弓型藻,并且这2个种与TN、TP及综合营养状态指数的组合变量也有较好的梯度响应关系,具备指示太湖湖滨带富营养化的可能,但定量指示意义尚待进一步研究。 相似文献