Dynamic changes of microbial community diversity in a photohydrogen producing reactor monitored by PCR-DGGE

A PCR-DGGE (denaturing gradient gel electrophoresis of polymerase chain reaction) protocol was used for monitoring the dynamic changes in the microbial population during photohydrogen production. Total DNA was extracted directly from the mixed bacterial community in the reactor and subjected to PCR with V3-16S rDNA and pufM gene primers, and the amplifications were then analyzed by DGGE. The DGGE patterns demonstrated the dynamics of community structure and the shift of microbial diversity, which correspond...     

SBAR中同步脱氮好氧颗粒污泥的菌种特性

采用气提式内循环间歇反应器进行好氧颗粒污泥培养,用分批培养法对好氧颗粒污泥中具有脱氮作用的菌种进行分离纯化.对各菌种进行了鉴别,通过培养过程中对氧气条件的控制,考察了各菌种反硝化生长特性和需氧性.结果表明,好氧颗粒污泥纯化培养可得到异养硝化-好氧反硝化菌以及兼性亚硝化菌和硝化菌,分离得到的反硝化菌在有氧反硝化条件下能够生长,因此好氧颗粒污泥中微生物具有多样性和较强的适应性,从侧面体现出好氧颗粒污泥微观结构的复杂性.     

超声气升式环流反应器降解乐果水溶液的动力学研究

采用超声气升式环流反应器(UALR),以臭氧气体为氧化剂,以有机磷农药乐果为典型污染物,研究其降解反应动力学规律.通过对乐果降解过程的表观动力学研究,发现乐果在单独超声辐射(不通入气体,即臭氧)、臭氧(O3)氧化和超声气升式环流反应器(UALR/O2)协同下的降解均符合表观一级动力学.在乐果初始质量浓度为50 mg/L、溶液初始pH为6.0、反应液体积80 mL、超声声强0.5W/cm2、O3流量200 L/h、温度20℃、处理时间4h的条件下,采用超声(US)、O3和UALR/O3工艺,乐果的去除率分别为27%、15%和90%,乐果降解的速率常数增强因子可达到4.816.进一步从UALR/O3系统中存在US、O3和羟基自由基(·OH)协同作用的降解机理,推导出了简化的机理动力学模型.     

沉降速率作为选择压对好氧颗粒污泥性质影响

在序批式反应器中以普通活性污泥驯化而得的好氧颗粒污泥为接种污泥,葡萄糖为碳源,研究作为选择压的沉降速率对好氧颗粒污泥性质的影响。结果表明:作为选择压的沉降速率与反应器中SV值和MLSS成反比关系;在沉降速率变化过程中,污泥龄、耗氧速率、胞外多聚物和COD去除率均产生变化。在本试验条件下,改变沉降速率,能改变反应器中生物量的洗出量并在一定程度上影响微生物群体的组成,从而影响活性的生物学性能;但生物相的改变限度在一定范围内,存在着动态平衡。污泥龄的波动与不同沉降速率下反应器中污泥中的胞外多聚物含量的变化有关。大量的胞外多聚物在颗粒污泥表面形成粘液层,对颗粒污泥形成保护。不同沉降速率下颗粒污泥的的胞外多聚物发生变化,进而影响颗粒污泥的稳定性。     

固定化甲烷八叠球菌(Methanosarcina)研究——厌氧颗粒污泥的形成

用实验室规模的UASB反应器处理豆制品废水培养厌氧颗粒污泥。通过对颗粒污泥形成过程中的产气率、进出水COD、水滞留期（HRT）、进出水挥发酸（乙酸、丙酸和丁酸）浓度、所产气体的甲烷含量等的变化分析和对颗粒污泥中优势产甲烷菌的扫描（SEM）和透射（TEM）电镜观察,阐明颗粒污泥的形成过程及特性。实验结果表明,消化器运转50d左右形成了颗粒污泥,厌氧颗粒污泥形成期间的平均产气率为5.3L/L·d,最高产气率达到了8.1L/L·d,进水和出水COD分别为3000～5500mg/L和800～3000mg/L,平均HRT为10.4h,平均出水乙酸、丙酸和丁酸浓度分别为264.1、519.8和104.6mg/L,所产气体的平均甲烷含量为60.6％,颗粒污泥为黑色,直径0.5～3.0mm不等,沉降速率为119.6m/h,其中的优势产甲烷菌为鬃毛甲烷菌（Methanosaeta）,而甲烷八叠球菌（Methanosarcina）存在甚少。     

Hydraulic characteristics of an anaerobic baffled reactor as onsite wastewater treatment system

The feasibility of using anaerobic baffled reactor(ABR)as onsite wastewater treatment system was discussed.The ABR consisted of one sedimentation chamber and three up-flow chambers in series was experimented under different peak flow factors(PFF of 1 to 6),superficial gas velocities(between 0.6 and 3.1 cm/hr)and hydraulic retention times(HRT)(24,36 and 48 hr).Residence time distribution(RTD)analyses were carried out to investigate the hydraulic characteristics of the ABR.It was found that the PFF resulted in hydraulic dead space.The dead space did not exceed 13% at PFF of 1,2 and 4 while there was 2-fold increase(26%)at PFF of 6.Superficial gas velocities did not result in more(biological)dead space.The mixing pattern of ABR tended to be a completelymixed reactor when PFF increased.Superficial gas velocities did not affect mixing pattern.The effects of PFF on mixing pattern could be minimized by higher HRT(48 hr).The tank-in-series(TIS)model(N=4)was suitable to describe the hydraulic behaviour of the studied system.The HRT of 48 hr was able to maintain the mixing pattern under different flow patterns,introducing satisfactory hydraulic efficiency.Chemical oxygen demand(COD)and total suspended solids(TSS)removals under all flow patterns were achieved more than 85% and 90%,respectively.The standard deviation of effluent COD and TSS concentration did not exceed 15 mg/L.     

中空纤维膜生物反应器处理生活污水的特性

中空纤维膜生物反应器生活污水处理特性的试验研究结果表明：Ｄ ＨＲＴ为１．５ｈ,ＣＯＤ容积负荷为５．７６ｋｇ／（ｍ＾３·ｄ）条件下,均可实现９０％以上的ＣＯＤ去除率;对ＮＨ３－Ｎ的去除率可稳定在９０％以上,高ＭＬＳＳ浓度８０００－１００００ｍｇ·Ｌ）提供了内部厌氧环境,使膜生物反应器的Ｔ－Ｎ去除率可达５０－６０％,中空纤维生物反应器处理高效,不受冲击负荷影响,操作管理方便,其生活物反应器体积比常规生     

Identical full-scale biogas-lift reactors (BLRs) with anaerobic granular sludge and residual activated sludge for brewery wastewater treatment and kinetic modeling

Two identical full-scale biogas-lift reactors treating brewery wastewater were inoculated with different types of sludge to compare their operational conditions, sludge characteristics, and kinetic models at a mesophilic temperature. One reactor （R1） started up with anaerobic granular sludge in 12 weeks and obtained a continuously average organic loading rate （OLR） of 7.4 kg chemical oxygen demand （COD）/（m3.day）, COD removal efficiency of 80%, and effluent COD of 450 mg/L. The other reactor （R2） started up with residual activated sludge in 30 weeks and granulation accomplished when the reactor reached an average OLR of 8.3 kg COD/（m^3·day）, COD removal efficiency of 90%, and effluent COD of 240 mg/L. Differences in sludge characteristics,biogas compositions, and biogas- lift processes may be accounted for the superior efficiency of the treatment performance of R2 over R1. Grau second-order and modified StoverKincannon models based on influent and effluent concentrations as well as hydraulic retention time were successfully used to develop kinetic parameters of the experimental data with high correlation coefficients （R2 〉 0.95）, which further showed that R2 had higher treatment performance than R1. These results demonstrated that residual activated sludge could be used effectively instead of anaerobic granular sludge despite the need for a longer time.     

高浓度有机废水二相厌氧消化过程特性研究

以填充床生物膜酸化反应器与上流式污泥床反应器（UASB）甲烷化反应器组成的二相厌氧消化装置处理高浓度啤酒废水或合成废水,最大处理能力为32～35kgCOD/d·m³。提出了二相工艺高负荷运行时最低必需酸化率的概念。进水浓度5000mgCOD/L,容积负荷30kgCOD/d·m³时,最低酸化率为28％。对主要操作参数的灵敏度分析表明,操作负荷、酸化率和进水碱度是影响COD去除率的主要操作参数。对二相厌氧消化系统中影响反应器内微生物群系的生态平衡、微生物本征活性和反应器宏观行为的主要因素进行了分类和综合讨论。     

基于氨氮,硝氮及乙酸条件下Anammox菌的培养

为探讨Anammox菌在氨氮、硝氮及乙酸条件下的富集特性,采用某城市污水处理厂A²/O系统中的生物填料作为MBBR的载体直接启动并运行.结果表明,在NH₄⁺-N、NO₃^--N及乙酸为基质的培养条件下,Anammox菌可在部分反硝化和厌氧氨氧化协同作用下快速富集.经过130d的富集培养,MBBR处理负荷（以N计）达到920.79mg/（m²·d）,Anammox活性（以NH₄⁺-N计）达到3 018.19mg/（m²·d）.高通量结果显示,经富集培养后,Ca.Brocadia占比从0.89%增至27.80%,为Anammox菌的主导菌属;Thauera占比从0.01%增至6.75%,Flavobacterium占比从0.29%增至11.72%,为部分反硝化菌的主导菌属.