Feasibility and advantage of biofilm-electrode reactor for phenol degradation

The new biofilm-electrode method was used for the phenol degradation, because of its low current requirement. The biofilm-electrode reactor consisted of immobilized degrading bacteria on Ti electrode as cathode and Ti/PbO2 electrode as anode. With the biofilmelectrode reactor in a divided electrolytic cell, the phenol degradation rate could achieve 100% at 18 h which was higher than using traditional methods, such as biological or electrochemical methods. Chemical oxygen demand (COD) removal rate of the biofilmelectrode reactor was also greater than that using biological and electrochemical method, and could reach 80% at 16 h. The results suggested that the biofilm-electrode reactor system can be used to treat wastewater with phenol.     

Effect of organic carbon on nitrification e ciency and community composition of nitrifying biofilms

The effects of organic carbon/inorganic nitrogen (C/N) ratio on the nitrification processes and the community shifts of nitrifying biofilms were investigated by kinetic comparison and denaturing gradient gel electrophoresis (DGGE) analysis. The results showed that the nitrification rate decreased with an increasing organic concentration. However, the effect became weak when the carbon concentration reached sufficiently high level. Denitrification was detected after organic carbon was added. The 12 h ammonium removal rate ranged from 85% to 30% at C/N = 0.5, 1, 2, 4, 8 and 16 compare to control (C/N = 0). The loss of nitrogen at C/N = 0.5, 1, 2, 4, (8 and 16 was 31%, 18%, 24%, 65%, 59% and 62% respectively, after 24 h. Sequence analysis of 16S rRNA gene fragments revealed that the dominant populations changed from nitrifying bacteria (Nitrosomonas europaea and Nitrobacter sp.) to denitrifying bacteria (Pseudomonas sp., Acidovorax sp. and Comamonas sp.) with C/N ratio increase. Although at high C/N ratio the denitrifying bacteria were the dominant populations, nitrifying bacteria grew simultaneously. Conrrespondingly, nitrification process coexisted with denitrification.     

碱法制浆造纸废水生物膜法达标排放技术

本文介绍了一种适用于碱法麦草制浆造纸废水达标排放处理工艺－生物膜法。在对四个示范工程的前期试验试验研究中证实了生物膜法在碱法麦草浆造纸废水处理的技术和经济可行性。     

油田含油污水达标外排生物处理影响因素研究

建立一体化生物处理反应器,采用自然富集挂膜方式培养微生物处理油田含油污水。考察主要影响因素温度、HRT、矿化度、有机负荷、生物填料性能等对反应器处理效能的影响。结果表明,通过此种方式挂膜、驯化成功的微生物可以适应油田含油污水高温高矿化度的水质特点。纤维球填料体系在水温45～65℃、HRT为10h、矿化度为15000mg/L、COD有机负荷在0.38～0.49kg/(m3.d)、油含量在22.1～78.3mg/L时处理效果较为理想,出水COD及油含量均值分别达到67.9、3.6mg/L,满足国家《污水综合排放标准》(GB8978-1996)一级排放标准。     

群体感应现象及其在生物膜法水处理中的应用

群体感应是指细菌通过感知分泌到环境中自诱导物浓度的变化来调整基因表达,增强其在复杂环境中的生存能力,是细菌行为社会化的体现.研究者对群体感应的微生态凋控机制进行了深入的探讨,包括自诱导物的合成、运输和对目的基因的表达调控,以及各信号通路之间的竞争关系对细菌适应环境的影响.本文分析了当前相关研究中的热点问题,提出了群体感应机制在生物法水处理领域中的潜在应用方式.图2参32     

两种生物膜反应器对黄河微污染水处理

通过MBBR工艺和陶粒生物滤池预处理黄河中下游微污染黄河水的对比试验研究,发现陶粒生物滤池和移动床生物膜反应器对CODMn的去除效果接近,但前者对UV254、三氯甲烷前体物和叶绿素a的去除效果均远远高于后者。陶粒生物滤池对氨氮的去除效果略高于移动床生物膜反应器,陶粒生物滤池出水中的亚硝酸盐氮浓度也较低。     

氢基质生物膜反应器去除对氯硝基苯的影响因素分析

基于MBfR(氢基质生物膜反应器)研究进水中ρ(p-CNB)(p-CNB为对氯硝基苯)和氢气压力对氢基质自养微生物还原降解p-CNB的影响,同时分析在ρ(p-CNB)和氢气压力影响下生物膜内电子受体生物还原的当量电子通量和还原动力学. 结果表明:提高进水中的ρ(p-CNB),p-CNB、p-CAN(对氯苯胺)的去除通量分别由0.014、0.011 g/(m2·d)升至0.099、0.060 g/(m2·d),但p-CNB的去除率由95.9%降至68.4%;提高氢气压力,p-CNB、p-CAN的去除通量分别由0.027、0.019 g/(m2·d)升至0.028、0.022 g/(m2·d),p-CNB去除率由93.1%升至95.1%,升幅均不大,说明进水ρ(p-CNB)比氢气压力更能直接影响p-CNB和p-CAN的去除通量及p-CNB去除率. 当量电子通量分配和还原动力学结果表明,p-CNB和p-CAN的还原对氢气压力升高的敏感性不强烈,进一步揭示降低进水中ρ(p-CNB)比提高氢气压力更能明显地促进微生物对p-CNB和p-CAN的去除效果. 氢气压力变化对硫酸盐还原和反硝化的影响程度高于p-CNB或p-CAN的还原,当氢气可利用率受限时,p-CNB或p-CAN的还原会由于电子供体的竞争而受到抑制.      

不同水力条件下排水管道生物膜中氮元素分布特性

在壁面剪切力为1.0,1.5,2.0Pa条件下培养排水管道生物膜,利用微电极测试技术对生物膜进行生长过程及成熟生物膜内部DO、NH4+、NO2-、NO3-分布规律进行研究.结果表明:1.0,1.5,2.0Pa条件下培养的生物膜厚度分别为(2.3±0.1),(1.9±0.1),(1.6±0.1)mm;1.0,1.5Pa条件下的生物膜内存在好氧、缺氧环境,在其中发生了硝化和反硝化反应,而2.0Pa条件下的生物膜内只存在好氧环境,只发生了硝化反应.生物膜厚度影响着溶解氧在膜内的分布,继而影响着N在膜内的迁移转化过程.     

“气浮-多面球-膜”集成工艺处理微污染湖泊水

采用“气浮-多面球-膜”集成装置处理高藻、低浊、有机物浓度较高的某微污染湖泊水,进行为期3个多月的小试试验,重点关注该集成工艺对有机物和藻类的处理效能。试验结果表明,该工艺能够有效去除有机物和藻类,对浊度、色度、嗅味、COD、氨氮、叶绿素a的平均去除率分别为97.8%、81.7%、71.4%、71.9%、61.4%和94.6%。膜单元对浊度的去除发挥主要作用,对浊度的平均去除率为56.7%。气浮单元对藻类、色度和嗅味的去除均发挥重要作用,对上述3项水质指标的平均去除率分别为73.5%、45.3%和50.1%。气浮和多面球生物处理单元对COD和氨氮的去除均发挥重要作用,气浮单元对COD和氨氮的平均去除率分别为30%、29.5%,多面球生物处理单元对COD和氨氮的平均去除率分别为30.8%、25.2%。     

氢基质生物膜反应器去除水中硒酸盐研究

利用连续搅拌氢基质生物膜反应器研究氢气(H2)分压,NO3--N,SO42-,SeO42-进水浓度对水中硒酸盐去除效果的影响.结果表明,H2分压是水中氧化态污染物NO3-,SO42-,SeO42-去除效果的重要影响因素,随着H2分压从0.02MPa上升到0.08MPa,SO42-的去除率从3.5%上升到46.3%,总Se的去除率从60.7%上升到82.1%,NO3-全过程都完全被还原为N2;随着NO3--N进水浓度从5mg/L增加到50mg/L,SO42-,SeO42-的去除率逐渐下降至0,并出现NO2-的积累;SO42-进水浓度的增加对NO3-,SeO42-去除效果影响不大,去除率分别保持在99.5%和65%以上,三种氧化态污染物得电子的优先级为NO3->SeO42->SO42-.在NO3--N浓度为10mg/L,SO42-浓度为25mg/L的水质条件下,反应器设置H2分压为0.04MPa,进水Se(VI)浓度在0.25~2mg/L的范围内总Se可以取得80%以上的去除效果.