强化脱氮MBBR中活性生物量的测定及其分布

设计开发了强化脱氮移动床生物膜反应器(MBBR)中试系统,采用耗氧呼吸速率法研究了各反应单元中的活性生物量分布情况,并分析了不同进水负荷对各单元中活性生物量的影响。研究发现,各反应单元生物膜中的异养活性生物量占比均在60%以上。缺氧单元每个填料上的异养活性生物量平均为0.56～0.86 mg/L(以COD计,下同),好氧单元的自养活性生物量占比可达到37.6%。此外,当SCOD负荷增加0.80～9.70 g/(m²·d)时,异养活性生物量可增加0.19～0.53 mg/L;当氨氮负荷增加0～1.15 g/(m2·d)时,自养活性生物量可增加0～0.11 mg/L。     

生态坝微生物与水生植物的水质净化机制研究

针对湖泊养殖污染问题,构建了由填料浮床和植物浮床组成的生态坝,考察了填料上生物膜的微生物活性及空心菜对氮、磷营养盐的去除效果,以获得生态坝的水质净化机制。结果表明:1作为在低浓度开放水体中生长的生物膜,虽然其活性比传统污水处理中活性污泥或生物膜的活性低,但仍具有明显的水质净化效果;VSS/SS值为0.42,比耗氧速率、比氨氧化速率、比亚硝酸盐氧化速率和比反硝化速率分别为(11.8±1.4)mg O_2/(g VSS·h)、(0.50±0.23)mg NH~+_4-N/(g VSS·h)、(0.15±0.01)mg NO~-_2-N/(g VSS·h)和(0.56±0.21)mg NO~-_3-N/(g VSS·h)。2空心菜对氮、磷的去除能力与氮、磷浓度呈正相关关系,其对低、中、高浓度模拟养殖水体中TN的平均去除率分别为31.7%、68.4%和75.9%,对NH~+_4-N的平均去除率分别为52.4%、74.8%和79.6%,对TP的平均去除率分别为40.8%、66.3%和78.2%,对PO~(3-)_4-P的平均去除率分别为48.0%、69.4%和80.5%。3生态坝上微生物和空心菜对NH~+_4-N的去除潜力分别是0.49和0.004 g/(m~2·d),微生物对NH~+_4-N的去除贡献大于水生植物;空心菜对TP的去除贡献大于微生物,去除潜力为0.48 mg/(m~2·d)。     

蜂窝胞壁厌氧生物滤池处理焦化废水的反应动力学研究

采用蜂窝胞壁厌氧生物滤池作为厌氧段,用于A/A/O工艺处理焦化废水,研究了蜂窝胞壁厌氧生物滤池的COD降解反应动力学和厌氧氨化反应动力学。结果表明,COD作为基质时的最大降解反应速率为12500.0 mg COD/(g VSS·d),影响COD降解反应的COD浓度为4 486.2 mg/L;氨氮作为基质时的最大氨化反应速率为357.1 mg氨氮/(gVSS·d),影响厌氧氨化反应的氨氮浓度为330.1 mg/L。     

双齿围沙蚕对饲料中氮元素的利用及其与体质量和温度的关系

对不同体质量双齿围沙蚕Perinereis aibuhitensis在不同温度条件下对牙鲆配合饲料中氮元素的利用和氮收支进行了研究。试验按沙蚕体湿重设置(0.40±0.19)、(1.00±0.22)、(2.00±0.50)g 3个组,分别记为S、M和L组,每组分别设16、20、24℃3个温度梯度。结果表明:1)20℃时各组双齿围沙蚕对氮的摄食率均达到最大值,平均为17.0 mg/(d.g),变幅为14.3～22.0 mg/(d.g);2)双齿围沙蚕于不同温度下对氮的摄食率均随体质量的增加而降低,其中,S组为10.5～22.0 mg/(d.g),M组和L组则分别为8.0～14.7、6.6～14.3 mg/(d.g),氮摄食率与体质量的关系可用幂函数式CN=aWb表示,其中a值在20℃时最高,为10.618,b值为-0.2076～-0.1911;3)双因素方差分析表明,温度和体质量对沙蚕的氮摄食率均有极显著影响(F=79.125,P<0.001;F=34.308,P<0.001);4)在本试验条件下,双齿围沙蚕对饲料中氮的累积率平均为11.8 mg/(d.g),以摄食氮为100%计,累积氮所占的比例最大,平均为88.99%,排粪氮次之,为9.43%,而排泄氮所占的比例最低,仅为1.58%。     

菲律宾蛤仔育苗用水系统中的细菌分布和周年变化特征

于2005年对大连庄河海量集团菲律宾蛤仔Ruditapes philippinarum育苗系统沉淀池、砂滤池几类不同功能细菌数量的变化进行了调查研究。结果表明:砂滤池出口水中的异养菌、氨化细菌、弧菌、亚硝化细菌数量均与沉淀池出口水中差异不明显;沉淀池水中的细菌数量均比泥中低,但不低于1个数量级。水和泥中的异养菌、弧菌最高值出现时间一致,分别出现在4月末和5月末;水中的亚硝化细菌最高值出现在7⁸月,泥中的出现在8月下旬8月,泥中的出现在8月下旬⁹月中旬;水中的氨化细菌最高值出现在8月下旬9月中旬;水中的氨化细菌最高值出现在8月下旬⁹月中旬,泥中的出现在9月中旬9月中旬,泥中的出现在9月中旬¹0上旬;泥中的反硝化、反硫化细菌最高值出现在610上旬;泥中的反硝化、反硫化细菌最高值出现在6⁹月。从异养细菌的数量看,沉淀池水质达到富营养化水平。     

微曝气生态浮床的净化效果与生物膜特性研究

大清河是滇池的主要支流之一,其水质污染严重,长期处于黑臭状态,针对这种情况开展了微曝气生态浮床净化其水质的研究.在进水量为6000～10000m3/d、曝气总量为50m3/h时,对TN、NH4+;-N、TP、SS和COD的平均去除率分别为77.4%、84.7%、75.1%、86.2%和72.5%.沿水流方向布设若干观测点,进一步对YDT弹性立体填料上生物膜的发育过程和特性进行了研究.系统水体流速为0.0353～0.1288m/s,弹性填料上的生物膜厚度在14～17d达到最大,生物膜量则在21d达到最大;生物膜的形态、厚度、数量、脱氢酶活性和细菌数量具有沿水流方向渐变的特点.进水端的生物膜较厚、成分复杂,生物膜量沿水流方向则呈逐步递减的趋势,脱氢酶活性呈现先上升再平稳下降的趋势,而异养茵和硝化菌群的数量逐渐增高.对于进水端而言,上层生物膜的脱氢酶活性和异养茵数量明显高于下层,而出水端的则变化不大.系统中硝化茵群的数量较高,与异养菌处在同一个数量级,其总量占异养茵数量的52.2%～138.1%.     

不同C/N值下SBBR中生物膜硝化特性研究

采用序批式生物膜反应器(SBBR),对C/N值分别为2和5条件下悬浮填料上的生物量、硝化活性、硝化菌份额及空间分布进行研究。结果表明,在填充率为20%的条件下,随着进水C/N值由2增加到5,生物膜的AUR由4.32 mg NH~+_4-N/(g VSS·h)减少到2.13 mg NH~+_4-N/(g VSS·h),NUR由12.6 mg NO~-_2-N/(g VSS·h)减少到9.0 mg NO~-_2-N/(g VSS·h)。氨氧化菌(AOB)在生物膜菌群中所占比例由1.9%降到1.3%,亚硝酸盐氧化菌(NOB)的比例则从18.9%下降到14.7%,AOB和NOB的优势菌群分别为Nitrosomonas和Nitrospira。生物膜切片显示,随着进水C/N值的升高,生物膜厚度逐渐增加,膜中的异养菌向外层迁移,而硝化菌向内层迁移,因此,C/N值决定着生物膜上微生物种群的空间分布。     

滤料中微生物活性控制氨氮和亚硝酸盐氮的研究

通过测定滤料中微生物的比耗氧呼吸速率,对比4个不同生物滤池中异养菌、亚硝酸盐氧化菌和氨氧化细菌的活性及去除水中氨氮和亚硝酸盐氮的效果。结果表明,炭砂滤池异养菌、亚硝酸盐氧化菌和氨氧化细菌的平均比好氧呼吸速率分别是2.28mg/(L·g·h)、1.46mg/(L·g·h)和0.89mg/(L·g·h),活性无烟煤滤池的异养菌、亚硝酸盐氧化菌和氨氧化细菌的平均比好氧呼吸速率分别是0.86mg/(L·g·h)、2.00 mg/(L·g·h)和2.93mg/(L·g·h)。炭砂滤池对亚硝酸盐氮和氨氮平均去除率分别是87.02%和37.32%,活性无烟煤对亚硝酸盐氮和氨氮平均去除率分别是87.02%和42.76%。炭砂滤池主要以异养菌作用为主,活性无烟煤滤池以亚硝酸盐氧化菌和氨氧化细菌作用为主,控制氨氮及亚硝酸盐氮比炭砂滤池的效果显著。     

硝化菌在不同载体中的富集效率研究

利用MBBR型、纤维球、细菌球三种载体在污水厂生化池中进行硝化菌群的富集,通过测定反应活性速率及微生物多样性对载体富集硝化菌群进行研究。结果表明,三种载体均在富集30 d左右时效果最佳。此时,细菌球载体富集硝化菌群中氨氧化菌(AOB)和亚硝酸盐氧化菌(NOB)的反应比速率分别达到了2.72、1.68 mg/(gVSS·h),通常作为限制性因素的AOB比速率相较于活性污泥提高了42.41%;且载体中富集的AOB/NOB值最高可达2.10,相较于活性污泥(AOB/NOB值约为1),载体选择性富集了更多的AOB。因此,按50%的填充体积投加细菌球挂膜载体,其AOB和NOB的反应比速率可分别提高71.2%和44.7%。高通量测序结果表明,细菌球载体中硝化菌数量占比高达7.40%,为活性污泥中硝化菌含量的2.1倍。另外,菌群种属分析结果表明,载体生物膜中的菌群比活性污泥更加多样化,增加了系统的稳定性和抗冲击性。     

限制基质条件下生物膜特性的研究

在氮作为限制基质的情况下,采用库爱特-泰勒反应器分别培养异养菌生物膜和异养/自养硝化菌混合生物膜。当生物膜系统达到稳定后,通过提高水力剪切力使生物膜发生脱落,以研究生物膜内层基本特性及活性变化。结果表明,随着水力强度的增加则生物膜发生逐步脱落,脱落前后两种生物膜的特性及微生物活性均发生了较大变化。在两种生物膜内,靠近载膜片的生物膜比靠近液相的生物膜具有更强的粘结力,能抵抗高达10 Pa的水力剪切力,且生物活性较高。对于自养硝化菌生物膜,在生物膜发生脱落后,残余生物膜对氨氮的表面去除速率几乎保持不变,甚至对氨氮的比去除速率还略有增加,说明自养硝化菌可能主要分布在生物膜的内层。     

焦化废水优势菌的筛选及复合优势菌的研究

利用测菌种的脱氢酶活性从焦化废水活性污泥中筛选出六株优势菌,对其不同组合的脱氢酶活性进行了测定,确定出六株优势菌的最佳组合,同时测定其生物增长量及对焦化废水的降解性能,证明三者之间有一定的对应性。     

Ultraviolet inactivation of selected bacteria and viruses with photoreactivation of the bacteria

u.v. dose/survival response curves were developed for E. coli, S. faecalis, poliovirus and reovirus. The influence of photoreactivation on the bacterial curves was examined. A maximum photoreactivation of 3.4 and 2.4 log of u.v. inactivated E. coli and S. faecalis populations, respectively, was observed. When allowing for photoreactivation, the dose required for 99.9% inactivation of the bacteria was approximately twice that required when photoreactivation was not considered. Reovirus, a double-standard RNA virus, was found to be significantly more resistant to u.v. radiation than poliovirus, a single-stranded RNA virus. The viruses in general, were found to be more resistant to u.v. radiation than the bacteria.     

Salmonella and other pathogenic bacteria

The bacterial origin of waterborne diseases was discovered at the turn of thiscentury. Introduction of slow sandfiltration, chlorination, and bacteriological control dates back to the same period. Although greater concern is given to-day to chemical pollutants or to viruses, bacteria are still a monace to countries with advanced water treatment.Within the last decade outbreaks were reported in Europe and the US due to Salmonellatypes, Shigella, E. Coli, and to Vibrio cholerae, generally due to deficiencies in treatment, and often caused by smaller private works.A wider spectrum of bacteria must be taken into consideration to-day, Enterobacteriaceae are still the most important including Yersinia, E. coli, Klebsiella, and Enterobacter. The opportunistic microorganisms (pseudomonada, Acinetobacter, Campylobacter, Aeromonas, Plavobacterium) can also a danger.     

The relationship between denitrifying bacteria and methanogenic bacteria in a mixed culture system of acclimated sludges

The interaction between denitrification and methanogenesis, with methanol functioning as an electron donor, has been examined through usage of a mixed culture system of denitrifying sludge and methanogenic sludge in an anaerobic bioreactor. Competition for methanol between these two kinds of biocommunity could not be observed, whereas methanogenesis was suppressed as long as nitrate and nitrite were made available in the mixed system. The inhibition of methanogenesis in the methanogenic sludge caused by nitrogen oxides was studied. The redox potential (E_h) of the culture was monitored and/or controlled for the sake of characterizing the behavior of the biocommunities. An addition of nitrite elevated the E_h of the culture less than nitrate did. Nitrite addition, however, exerted a stronger inhibitory effect on methanogenesis as compared to nitrate at the same concentration. The influence of redox potential on the methanation of methanol was examined by using a methanogenic sludge in the E_h-stat batch culture. The hypothesis that the inhibitory effect being expressed by the nitrogen oxides is not simply attributed to an elevation of the redox potential of the culture is supported by the experimental results. The toxic effect of the nitrogen oxides themselves could also have possibly contributed significantly.     

对产甲烷细菌的分析与研究

介绍了产甲烷细菌的形态特征、生理特征、营养特征,研究了产甲烷细菌的分离,探讨了产甲烷细菌在废水处理和农村的应用,指出有必要充分利用产甲烷细菌进行废水处理以实现甲烷的资源化利用。     

Comparative electrochemical inactivation of bacteria and bacteriophage

Electric fields and currents have been shown to be capable of disinfecting drinking water and reducing the numbers of bacteria and yeast in food. However, little research has been conducted regarding the effectiveness of electric fields and currents in the inactivation of viruses. The objective of this study was to compare the ability of bacteria and bacteriophage to survive exposure to direct electric current in an electrochemical cell, where they would be subject to irreversible membrane permeabilization processes, direct oxidation of cellular/viral constituents by electric current, and disinfection by electrochemically generated oxidants. Suspensions of the bacteria Escherichia coli and Pseudomonas aeruginosa and bacteriophage MS2 and PRD1 at both high (approximately 1 x 10(6)CFU or PFU/mL) and low (approximately 1 x 10(3)CFU or PFU/mL) population densities were exposed to currents ranging from 25 to 350 mA in 5s pulses. Post-exposure plaque counts of the bacteriophage were proportionally higher than bacterial culturable counts at corresponding current exposures. E. coli and MS2 were then exposed to 5 mA for 20 min at both high and low population densities. The inactivation rate of E. coli was 2.1-4.3 times greater than that of MS2. Both bacteria and bacteriophage were more resistant to exposure to direct current at higher population densities. Also, amelioration of inactivation within the electrochemical cell by the reducing agent glutathione indicates the major mechanism of inactivation in the electrochemical cell is disinfection by electrochemically generated oxidants. The implications of these results are that technologies relying upon direct current to reduce the numbers of microbes in food and water may not be sufficient to reduce the numbers of potentially pathogenic viruses and ensure the safety of the treated food or water.     

Iron and manganese bacteria in Ranney wells

From an examination of water samples and of relevant plates (glass and metal ones) in the water of Ranney wells, iron and manganese bacteria have been studied.     

聚磷菌的诱导驯化与分离

采用A/O方式运行的SBR反应器对回流污泥进行诱导驯化,结果表明在较短时间内系统有明显的聚磷特征,A/O方式运行的反应器除磷效率大于95%,从运行稳定的系统中进行微生物的分离,经过数次分离得到纯种的菌株,通过染色试验表明,菌体内含有异染颗粒.     

Indicator bacteria and limnological parameters in fish ponds

The populations of indicator bacteria (mesophilic, coliform and fecal streptococci) together with relevant limnological parameters (temperature, oxygen, BOD and chlorophyll-) were recorded during a 6 year study of three eutrophic ponds. Ecosystems were manipulated with fish (Cyprinus carpio) in 2-year management cycles: in spring of the first year, the pond was stocked with young fish, and in the fall of the second year it was drained and mature fish were harvested. Fish management had a direct influence on bacterial numbers and on the basic parameters of the systems. A statistical analysis using t-tests found significant differences in oxygen concentration, chlorophyll- and BOD during both years of fish management. A water temperature model was calculated on an extensive homogenous data set (197 measurements), by fitting a regression curve. During each season, populations of indicator bacteria increased with increasing water temperature, and maximal numbers of bacteria were recorded during the summer months. Correlation analysis (fitted Spearman correlation coefficient) confirmed that temperature had a positive significant effect on population dynamics. The results demonstrate that fish stocking can affect bacterial population, in the sense that during high fish biomass (second years) the numbers of indicator bacteria as well as BOD and phytoplankton were higher. If pond water quality must be optimised for the purposes of drinking or recreation, the planned fish yield may have to be reduced.     

Rapid enumeration of water bacteria

The research reported in this paper is devoted towards the development of a rapid bacteriological test for water. The proposed technique consists in measuring “Cold T.C.A. insoluble portion” of metabolized phosphorus in multiplying bacterial cells with recourse to radioactive phosphorus-32 as a tracer and enumerates bacteria in 1 h incubation time. A linear correlation (coefficient of correlation = +0·989) has been shown to exist between this portion of phosphorus and cell population for bacterial species of public-health significance, thereby providing a point d'appui for this approach of enumerating water bacteria.The data reported in the paper reveal a promise for the differential enumeration of Grams positive and negative cells by incorporating suitable chemical inhibitors in appropriate concentrations in the test portions for rapid test.The technique has been exhibited to be applicable to field samples drawn from surface and underground sources of water. Its reproducibility and economics are comparable with “Standard Method” procedures.