好氧颗粒污泥藻酸盐提取物的聚集形态研究

为探寻细菌藻酸盐对好氧污泥颗粒化的作用,借鉴海藻酸盐的提取方法,将好氧颗粒污泥中的细菌藻酸盐提取和鉴定后,对10～500mg·L-1,范围内不同浓度的藻酸盐提取物在50mg·L-1CaCl2溶液中的聚集形态进行了原子力显微镜观察.结果表明,细菌藻酸盐占好氧颗粒污泥干重的35.1%±1.9%.在CaCl2作用下,藻酸盐提取物具有从无序聚集成有序状态的超分子自组装特性,随着浓度的增加,藻酸盐提取物自发聚集,由纳米级的胶束微球聚集为微米级的花状,进而连接成网状成层堆积.好氧颗粒污泥中细菌藻酸盐通过形成具有三维空间结构的细菌藻酸盐-金属凝胶而对颗粒污泥的形成起骨架作用.其中,细菌藻酸盐-Ca2 凝胶在颗粒污泥的形成和维持其稳定结构中起主要作用.     

思茅松种群的自疏研究

在野外考察的基础上,运用密度变化、相对径级离散度、自疏结局分析等方法对思茅松种群的自疏进行了研究。基于研究结果,认为思茅松纯林的管理应以夫然更新为主、人工抚育间伐为辅。     

A/O膜生物反应器处理垃圾渗滤液的试验研究

本文通过试验采用A/O膜生物反应器对垃圾渗滤液进行了处理,结果表明:当厌氧水力停留时为15 h、好氧水力停留时间为30 h、回流比为300%～400%时,CODcr、BOD5、氨氮及TN的平均去除率分别为85.2%、91.6%、88%和43.9%;人工投加碳源后,TN的平均去除率提高到77.7%;在反应器好氧区中形成了...     

菹草种群对湖泊水质空间分布的影响

对南京玄武湖菹草种群内外水体进行了26 h连续理化指标监测及分析,研究菹草种群对湖泊水体的环境效应.结果表明,表层水体DO最高值(11.85 mg/L)、最低值(9.90 mg//L)均出现在种群内,种群外水域DO含量随与种群距离增加而递减;种群内及开阔水域表层与底层DO差异较小,而种群与开阔水域交界处表层与底层DO差...     

16S rDNA 克隆文库法分析Biostyr 曝气生物滤池处理城市污水的细菌多样性研究

采用分子生物学手段16SrDNA克隆文库方法,对第三代生物膜法代表工艺Biostyr曝气生物滤池（BAF）中滤料表面细菌进行了多样性研究.从16SrDNA克隆文库中随机挑选了50个克隆子进行序列测定（约1.5kb）,对测序结果进行了BLAST对比.结果表明,BiostyrBAF系统中的细菌群落具有高度多样性,有41个克...     

Succession of bacterial community along with the removal of heavy crude oil pollutants by multiple biostimulation treatments in the Yellow River Delta, China

Multiple biostimulation treatments were applied to enhance the removal of heavy crude oil pollutants in the saline soil of Yellow River Delta. Changes of the soil bacterial community were monitored using the terminal restriction fragment length polymorphism (T-RFLP) and clone library analyses. The 140-day microcosm experiments showed that low C:N:P ratio, high availability of surfactant and addition of bulking agent significantly enhanced the performance, leading to the highest total petroleum hydrocarbon removal. Meanwhile, the bacterial community was remarkably changed by the multiple biostimulation treatments, with the Deltaproteobacteria, Firmicutes, Actinobacteria, Acidobacteria and Planctomycetes being inhibited and the Alpha- and Beta-proteobacteria and some unknown Gammaproteobacteria bacteria being enriched. In addition, different hydrocarbon-degraders came to power in the following turn. At the first stage, the Alcanivorax-veldXed Gammaproteobacteria bacteria dominated in the biostimulated soil and contributed mainly to the biodegradation of easily degradable portion of the heavy crude oil. Then the bacteria belonging to Alphaproteobacteria, followed by bacteria belonging to Candidate division OD1, became the dominant oil-degraders to degrade the remaining recalcitrant constituents of the heavy crude oil.     

Bacterial community composition and abundance in leachate of semi-aerobic and anaerobic landfills

Different municipal solid waste landfill methods and landfill ages had crucial impacts on bacterial abundance and composition in leachate.     

Comparison of bacterial community structures in two systems of a sewage treatment plant using PCR-DGGE analysis

Bacterial community was investigated during sludge bulking period using combination of PCR amplification of 16sRNA genes with DGGE analysis.     

Isolation and algae-lysing characteristics of the algicidal bacterium B5

Water blooms have become a worldwide environmental problem.Recently,algicidal bacteria have attracted wide attention as possible agents for inhibiting algal water blooms.In this study,one strain of algicidal bacterium B5 was isolated from activated sludge.On the basis of analysis of its physiological characteristics and 16S rDNA gene sequence,it was identified as Bacillusfusiformis.Its algae- lysing characteristics on Microcystis aeruginosa,Chlorella and Scenedesmus were tested.The results showed that:(1)the algicidal bacterium B5 is a Gram-negative bacterium.The 16S rDNA nucleotide sequence homology of strain B5 with 2 strains of B.fusiformis reached 99.86%,so B5 was identified as B.fusiformis;(2)the algal-lysing effects of the algicidal bacterium B5 on M.aeruginosa, Chlorella and Scenedesmus were pronounced.The initial bacterial and algal cell densities strongly influence the removal rates of chlorophyll-α.The greater the initial bacterial cell density,the faster the degradation of chlorophyll-α.The greater the initial algal cell density,the slower the degradation of chlorophyll-α.When the bacterial cell density was 3.6 x l07 cells/ml,nearly 90% of chlorophyll-αwas removed.When the chlorophyll-αconcentration was less than 550μg/L,about 70% was removed;(3)the strain B5 lysed algae by secreting metabolites and these metabolites could bear heat treatment.