亚硝酸盐为电子受体反硝化除磷工艺的可行性

采用序批式反应器(SBR),以亚硝酸盐为电子受体,探讨了厌氧/缺氧条件下反硝化除磷工艺的可行性,并通过间歇实验考察了亚硝酸盐浓度、进水COD浓度和进水pH值对反硝化除磷工艺的影响.结果表明,亚硝酸盐作为电子受体的同步脱氮除磷过程是完全可以实现的,控制NO₂^--N浓度为35±5mg/L、厌氧段进水pH值为8.0±0.1,缺氧段进水pH值为7.2±0.1、COD浓度为400mg/L时,反硝化除磷效果最佳.     

氯代苯类化合物对江水细菌的毒性及QSAR研究

采用细菌生长抑制实验,测定了18种氯苯类化合物对长江水中混合细菌的毒性,得到24 hIC₅₀值,-1gIC₅₀为3.65～4.32,其中,毒性最弱的是氯苯,毒性最强的是1,2,4-三氯苯.选用分子连接性指数法对毒性数据进行定量结构活性关系(QSAR)研究.结果表明,氯苯类化合物对江水细菌的毒性与苯环上取代基的种类、数目和位置有关,价分子连接性指数0XV和7X_CHV能够很好地描述氯苯类化合物对江水细菌的毒性.方程-1gIC₅₀=0.8390XV-25.3727X_CHV+0.802的稳健性很好,该模型的预测值与毒性实测值之间的相关系数达0.948.      

附生假单胞菌信号分子对铜绿微囊藻磷代谢的影响

通过在不同的磷浓度和细胞浓度的铜绿微囊藻培养液中添加附生假单胞菌信号分子,研究了附生假单胞菌信号分子对铜绿微囊藻生长及磷代谢的影响．结果表明,与对照相比,附生假单胞菌信号分子能抑制高浓度铜绿微囊藻的生长,促使低浓度铜绿微囊藻衰亡,并可以促进在衰亡期藻细胞内磷的积累．附生假单胞菌的信号分子可以在附生假单胞菌-铜绿微囊藻种间起作用,影响铜绿微囊藻的生长和磷代谢。     

降解菌对堆肥中多环芳烃降解作用的研究

通过在堆肥中加入经过驯化的降解菌这种土壤有机污染生物修复技术 ,对堆肥中多环芳烃的浓度变化进行监测 ,从而了解降解菌对堆肥中多环芳烃的降解作用。实验结果表明 ,降解菌的加入能明显地提高多环芳烃的降解率 ,本次实验中 ,菲、芴的去除率提高了 2 5 %左右 ,芘的去除率提高了约 4 5 %。     

复合生物滤池处理NH3和H2S混合恶臭气体的实验研究

采用复合生物滤池处理NH₃和H₂S酸碱混合气体,其中复合生物滤池由生物滴滤池和生物过滤池组成.研究表明:在气体流量为0.9～1.4 m3/h,气体质量浓度为15 mg/m3,营养液喷淋量为4.56 L/h时,出气NH₃和H₂S的质量浓度分别达到<恶臭污染物排放标准>(GB14554-93)中的一级和二级排放标准,除臭效果好.研究还表明:复合生物滤池中微生物的生长条件差别较大,在生物滴滤池内生长的微生物为枯草芽孢杆菌、钟虫等细菌,而在生物过滤池内生长的微生物则为白曲霉菌、葡萄球菌等真菌.      

Photobiological production of hydrogen by the waste water treatment with anaerobic photosynthetic Purple bacteria

In this paper selected references about experience gained with photosynthetic bacteria in anaerobic process for either water treatment or hydrogen production are given. In particular experimental data about the hydrogen evolution rate, hydrogen yield and substrate efficiency in relationship to the nutrient conditions as well as about the behavior of some different species are presented. The limiting role of the nitrogen source is being discussed.     

Response of selected poultry cecal probiotic bacteria and a primary poultry salmonella typhimurium isolate grown with or without glucose in liquid batch culture

Abstract

The objective of this study was to determine whether fermentation by a cecal probiotic co‐culture of an Enterococcus sp. and Veillonella sp. would inhibit the in vitro growth of a S typhimurium poultry isolate. The growth rates of S. typhimurium and Enterococcus were significantly reduced at pH 5. At the two pH levels, there was a significant (p < 0.001) increase at 24 h in colony forming units for each of the bacteria enumerated from the mixed culture compared to the respective pure culture enumerations. S. typhimurium was not inhibited in mixed cultures. The mixed cultures produced more acetate than any of the pure cultures and lactate produced by Enterococcus appeared to be utilized by Veillonella.     

Aspects of Tests and Assessment of Filtering Materials Used for Respiratory Protection Against Bioaerosols. Part II: Sweat in the Environment,Microorganisms in the Form of a Bioaerosol

The second part of the article presents the results of a study of antimicrobial activity of filter nonwovens with an addition of biocides, as a function of the presence of sweat in the environment and the method of microbe deposition on a nonwoven in the form of a liquid and a bioaerosol. At the same time, the filtration efficiency of nonwovens against microorganisms in the form of a bioaerosol was tested with the dynamic method. The results showed that the addition of sweat on the surface of a nonwoven resulted in an insignificant decrease of biological activity that still remained high. Moreover, an active nonwoven showed biostatic and biocidal activity only when microbes were deposited on the surface in the form of a solution. The nonwoven did not show any biological activity after deposition of microorganisms with the dynamical method in the form of a bioaerosol.     

低能离子诱变产表面活性剂的烃降解菌研究

为有效治理石油污染土壤,从长期遭受石油污染的土壤中筛选出一株烃降解菌8-11作为出发菌,利用低能N+注入烃降解菌进行诱变,在能量为20 keV、剂量为90×2.6×1013ions/cm2条件下筛选出一株高效烃降解菌——诱变菌23。原油摇瓶发酵实验表明诱变菌对原油的降解率达到74%;降解后原油的全烃气相色谱图显示,经过7 d的作用,原油中的正构烷烃完全降解。诱变菌23能够产生大量的生物表面活性物质,傅里叶红外光谱分析表明其产生的生物活性物质为糖脂类化合物,该糖脂类生物表面活性剂能使发酵液的表面张力从空白对照的56.1 mN/m降低为29.3 mN/m。研究表明诱变菌23具有较高的烃降解能力,能有效降低表面张力,具有较大的应用潜力。     

低温下活性污泥膨胀的微生物群落结构研究

采用水质参数指标测定和高通量测序技术,探讨了郑州某污水处理厂冬季间歇性污泥膨胀机制.结果表明该厂活性污泥的污泥容积指数(SVI值)的变化与季节温度变化有显著的负相关性,1~4月及12月易发生污泥膨胀,但是不影响出水水质.高通量测序技术分析发现污泥膨胀月份泥样的微生物群落结构要显著不同于未膨胀月份.该厂发生丝状菌污泥膨胀的优势丝状菌为腐螺旋菌科Saprospiraceae和黄杆菌科Flavobacterium.因此,低温导致活性污泥微生物群落结构变化是引起该厂活性污泥膨胀的原因.