Denitrification and biofilm growth in a pilot-scale biofilter packed with suspended carriers for biological nitrogen removal from secondary effluent

Tertiary denitrification is an effective method for nitrogen removal from wastewater. A pilot-scale biofilter packed with suspended carriers was operated for tertiary denitrification with ethanol as the organic carbon source. Long-term performance, biokinetics of denitrification and biofilm growth were evaluated under filtration velocities of 6, 10 and 14 m/hr. The pilot-scale biofilter removed nitrate from the secondary effluent effectively, and the nitrate nitrogen(NO_3-N) removal percentage was 82%, 78% and 55% at the filtration velocities of 6, 10 and 14 m/hr, respectively. At the filtration velocities of 6 and 10 m/hr, the nitrate removal loading rate increased with increasing influent nitrate loading rates, while at the filtration velocity of 14 m/hr, the removal loading rate and the influent loading rate were uncorrelated.During denitrification, the ratio of consumed chemical oxygen demand to removed NO_3-N was 3.99–4.52 mg/mg. Under the filtration velocities of 6, 10 and 14 m/hr, the maximum denitrification rate was 3.12, 4.86 and 4.42 g N/(m~2·day), the half-saturation constant was 2.61, 1.05 and 1.17 mg/L, and the half-order coefficient was 0.22, 0.32 and 0.24(mg/L)1/2/min,respectively. The biofilm biomass increased with increasing filtration velocity and was 2845,5124 and 7324 mg VSS/m~2 at filtration velocities of 6, 10 and 14 m/hr, respectively. The highest biofilm density was 44 mg/cm~3 at the filtration velocity of 14 m/hr. Due to the low influent loading rate, biofilm biomass and thickness were lowest at the filtration velocity of 6 m/hr.     

浮动生物膜床反应器运行效果分析

对采用浮动生物膜床反应器处理高校生活污水工艺的运行效果进行了分析.通过定期监测代表性水质参数CODCr、BOD5、TP和TN,分析了各处理池对污水的处理效率.结果表明:此污水处理系统在运行效果下降期间,对日常用水变化量范围内的CODCr和BOD5能够起到相对稳定的净化作用;对TP和TN去除能力较差;沉淀池运行不稳是导致整个系统处理能力下降的主要原因.     

缺氧池填料投配比对A~2/O-MBR工艺反硝化除磷的影响

按20%的投配比往好氧1,2池中加入相同数量的悬浮式填料,将传统A2/O工艺转变为A2/O-MBR复合工艺。通过处理实际市政污水,重点考察了在缺氧池中不同填料投配比条件下,复合工艺的去除效果以及反硝化除磷效果。实验结果表明,当缺氧池中填料投配比为20%时,装置总体的处理效果最好。COD、总氮、氨氮和总磷的去除率分别达到了81.1%、80.3%、100%和85.2%。当投配比为10%时,反硝化除磷效果最明显,占总除磷量的48.3%。从经济角度出发,10%的投配比为最佳投配比。     

天然沸石处理富营养化水的生物基作用研究

采用实验室模拟封闭池塘水体的方法研究了天然沸石处理富营养化水的机理与方法,采用电镜等手段观察和研究了沸石生物膜的形态。结果表明,天然沸石是一种良好的生物基材料,具备生物膜功能的沸石对富营养化池塘水中的NH₃-N和COD能保持长效和稳定的去除作用,两者的去除率分别为85%～88%和64%～73%。对磷的去除以吸附为主,去除率可达27%,吸附饱和后沸石失去除磷效果。天然沸石的吸附、离子交换和生物作用,能形成一个完整和谐的吸收消化系统,使天然沸石始终处于吸附未饱和状态,是沸石去除NH₃-N和COD的重要机理。天然沸石来源广泛,价格不高,在富营养化池塘水净化中,具有效果持久、无二次污染和不影响水体景观的特点,在提高和改善水质的同时,对增强水生态系统的自净能力有利,是一种安全和纯生态的处理方法。     

一体式悬浮载体生物流化床啤酒废水处理研究

中小型点源污染的控制是提高水环境质量和解决水资源短缺的关键。一体式悬浮载体生物流化床(ISCBFB)占地面积小、处理效率高,适合中小型点源污水的处理。以公牛啤酒厂废水为试验原水进行了研究,试验期间进水COD平均浓度1 213.38 mg/L,出水平均为50.75 mg/L,平均去除率达到95.82%。进水氨氮平均浓度为22.50 mg/L,出水平均为4.31 mg/L,平均去除率达到80.99%,试验中全部出水水样COD及氨氮浓度均达到国家《污水综合排放标准》(GB 8978-1988)一级标准。总之,一体式悬浮载体生物流化床对啤酒废水具有很好的去除效果。     

植物作为反硝化碳源

研究得到一种新型的筛选反硝化碳源的方法:可以通过比较材料浸出液的C/N值,筛选出有效的反硝化碳源;对芦苇秸秆、梧桐黄叶、梧桐绿叶、橘树叶、玉米秸秆和玉米芯6种材料浸出液的C/N值进行了研究,其中当以叶片作为反硝化固相碳源时,应该选取新鲜叶片作为研究对象。橘树叶和玉米芯均属于良好的反硝化碳源。以驯化后的河泥作为反硝化污泥,可以利用橘树叶或者玉米芯作为反硝化固相碳源,进行持续脱氮除磷反应,其中橘树叶脱氮效果强于玉米芯,而玉米芯除磷能力强于橘树叶。扫描电镜实验表明,橘树叶和玉米芯均适合作为生物膜载体。     

铀吸附实验研究现状

介绍了铀吸附实验的研究现状,对吸附铀的各种载体进行了总结。目前,主要采用静态法（批示法）和动态法（柱法）进行铀的吸附实验研究。吸附铀的载体主要有粘土,金属的水合氧化物等肢体,藻类及菌类,树脂等。主要考察pH值、温度、吸附时间、阴离子、阳离子、细菌浓度、铀浓度等对吸附速率及吸附量的影响。     

BTMT生物膜载体对厌氧氨氧化反应器启动的影响

采用两套厌氧氨氧化反应器R1和R2,研究了BMTM生物膜载体对厌氧氨氧化工艺启动特性的影响.结果表明,R1采用UASB反应器启动厌氧氨氧化反应器,经140d运行,对氨氮和亚硝酸盐氮的去除率仅达到54.6%和58.8%,氨氮与亚硝酸盐氮去除负荷之和仅为0.09kg/(m3×d),随后,向其上部投加0.6L BMTM载体,经过26d运行,氨氮及亚硝酸盐氮去除率分别迅速提升至92.5%和97.4%,R1的启动速度较之前有明显提高;R2采用BMTM载体启动上流式填料床生物膜反应器厌氧氨氧化工艺,经过83d的运行,氨氮及亚硝酸盐氮去除率分别达到83.6%和89.4%,氨氮与亚硝酸盐氮去除负荷之和达0.22kg/(m3×d),启动速度较R1大幅提高.     

生物膜填料比表面积对移动床生物膜反应器中非甾体抗炎药去除的影响

非甾体抗炎药（Nonsteroidal anti-inflammatory pharmaceuticals,NSAIDs）是污水中高频检出的新兴污染物.污水处理厂对其去除效果不佳,出水中的NSAIDs会对水生生态系统造成潜在不利影响.移动床生物膜反应器（Moving bed biofilm reactors,MBBRs）是一种去除污水中新兴污染物极有潜力的生物处理技术.MBBRs中填料的比表面积对NSAIDs去除影响较大.本研究选用3组不同比表面积的填料（S填料：460 m²·m^-3,M填料：800 m²·m^-3,L填料：1200 m²·m^-3）,采用实验室规模的MBBRs运行150 d去除环境浓度（50 μg·L^-1）的NSAIDs—双氯芬酸（Diclofenac,DCF）、萘普生（Naproxen,NPX）和布洛芬（Ibuprofen,IBP）,考察了填料比表面积对MBBRs中NSAIDs去除的影响及其潜在的影响机制.结果表明,填料的比表面积对NPX、IBP的去除具有显著影响（p<0.05）,对DCF去除效果影响不明显.S、L填料有利于提高生物膜的活性（ATP浓度和脱氢酶活性）,而ATP浓度和脱氢酶活性与NPX和IBP的去除呈正相关.门水平上的变形菌门及属水平上的Steroidobacter、Acinetobacter的相对丰度随比表面积增加而提高,且变形菌门及Steroidobacter、Acinetobacter的相对分度与NPX、IBP去除规律一致.本研究揭示了MBBRs中填料比表面积通过影响微生物活性及群落结构从而影响NSAIDs去除的潜在机制,为MBBRs对新兴污染物的去除提供了参考.     

Generating better energy indicators: Addressing the existence of multiple scales and multiple dimensions

High energy prices and the growing concern for “Peak Oil” have put energy analysis, once again, on the front burner. However, before speculating about possible roadmaps regarding our energy future, it would be wise to develop better quantitative analyses. This paper flags the existence of systemic epistemological flaws in the current use of aggregate energy indicators and presents an alternative approach capable of dealing with the issue of multiple dimensions and multiple scales. Starting from a critical appraisal of the aggregate indicator “Economic Energy Intensity” it shows that economic and biophysical variables are often correlated and that their value is determined by characteristics which can only observed across different levels and scales. Complex metabolic systems (systems that use energy to maintain and reproduce themselves) are operating simultaneously at different scales. This implies that changes in the characteristics of parts, defined at the local scale, and changes in the characteristics of the whole, defined at the large scale can only be obtained after establishing a scaling mechanism in the analysis. In order to deal with the issue of scale in energy accounting, we propose to make a distinction between three different categories: (i) primary energy sources (PES) - establishing a link between energy quantities and the associated requirement of biophysical gradients, at the large scale, on the interface black-box/context; (ii) energy carriers (EC) - defining the set of energy inputs required by technical devices for expressing useful functions, at the local scale, within the parts operating inside the black-box; (iii) end uses (EU) the set of functions to be expressed by society across hierarchical levels for reproducing itself. Finally, the paper presents examples of quantitative results obtained using an innovative method of analysis - Multi-Scale Integrated Analysis of Societal and Ecosystem Metabolism (MuSIASEM). We conclude that by using this new accounting method it is possible to generate a better understanding of external and internal constraints determining the desirability and viability of the metabolic pattern of societies.