Ca^(2+)在好氧颗粒污泥形成中的作用  

Role of Ca^(2+) in the Formation of Glucose-fed Aerobic Granular Sludge in Sequencing Batch Reactor

作　　者：杨新萍[1] 韩娇[1] 周立祥[1] 

机构地区：[1]南京农业大学资源与环境学院环境工程系,南京210095

出　　处：《环境科学》2010年第5期1269-1273,共5页Environmental Science

基　　金：国家高技术研究发展计划(863)项目(2006AA06Z314)

摘　　要：通过运行序批式生物反应器与摇瓶实验相结合方法,在进水中投加不同数量Ca2+(0～200mg/L),考察了Ca2+在好氧颗粒污泥形成中的作用.当SBRⅠ、Ⅱ进水Ca2+含量分别为30、100mg/L,运行20d后,两反应器中均出现了好氧颗粒污泥.运行前50d,SBRⅠ中颗粒污泥浓度MLSS与污泥沉降指数SVI指标明显好于SBRⅡ;运行80d后,SBRⅠ、Ⅱ中污泥浓度MLSS均稳定在7.5g/L,SVI分别为46～48mL/g、45～47mL/g,差异很小.反应器运行90d后,SBRⅠ、Ⅱ中污泥Zeta(ζ)电位为-12.5～-12.6mV;摇瓶实验中,当进水Ca2+为0～200mg/L,运行至60d时,摇瓶中污泥Zeta电位为-14.1～-14.4mV;进水中Ca2+含量的增加对污泥Zeta电位影响很小,没有引起好氧颗粒污泥Zeta电位的明显差异,电中和在颗粒污泥形成过程中并不起重要作用.随着进水Ca2+浓度增加,颗粒污泥中的微生物数量与种类都逐渐丰富,Ca2+有助于促进污泥中微生物多样性.接种污泥及SBR中颗粒污泥的元素含量分析表明,好氧颗粒污泥Ⅰ、Ⅱ与接种污泥相比,颗粒污泥中Ca、Mg、K、Na含量均有所减少,Fe含量分别增加了4.42%、7.82%.具有良好絮凝作用的金属离子与EPS间形成的高分子生物聚合体可能是促进好氧颗粒污泥形成的主要原因.反应器运行期间,SBRⅡ对污染物的去除性能始终高于SBRⅠ,运行70d后,SBRⅠ、Ⅱ中颗粒污泥对NH4+、COD去除率较高达到90%以上,对TN、TP的去除率为65%～70%.Influence of Ca^2＋ on glucose-fed aerobic granule was investigated through sequencing batch reactor（SBR） and shaking flask experiments. Granules of two SBRs spiked with 30 mg/L and 100 mg/L of Ca2 ＋ could be observed visually on day 20. In the first 50 days,the SBRⅡ had higher mixed liquor suspended solid（MLSS） and lower sludge volume index（SVI） than those of SBRⅠ. After 50 days,the difference of granule performance in two reactors gradually be reduced and little differences were found on day 80 or more, for example,MLSS of SBRⅠ,Ⅱ was 7. 5 g/L and SVI arrived at 46-48 mL/g and 45-47 mL/g respectively. After 90 days,sludge Zeta potential of SBRⅠ,Ⅱreached - 12. 5-- 12. 6 mV. Furthermore,with influent of 0-200 mg/L Ca2 ＋ ,sludge Zeta potential of shaking flask reached - 14. 4-14 after 50 days. Ca2 ＋ concentration of influent had little influence on Zeta potential of sludge during granulation process. Microbiological observations confirmed some appreciable changes in microorganism population and diversities with the increase of Ca2 ＋ concentration of influent. The role of Ca2 ＋ in bioflocculation of granule can be mainly attributed to its cation bridging instead of charge neutralization. The elemental analysis of seed sludge and aerobic granule by X-ray fluorescence （ XRF） showed that the content of Ca,Mg,K,and Na in granule were less than seed sludge expect for Fe,increasing 4. 42% and 7. 82% respectively. Divalent metal ions such as Ca2 ＋ and Fe^2＋ were probably constituent of biopolymer. It was possible that the binding of divalent metal ion with extracellular polymeric substances（EPS） enhanced the granulation of seed sludge. Consequently,the pollutant removal efficiency of SBRⅡ was higher than that of SBRⅠthroughtout the trial. Both NH 4＋ -N and COD removal efficiencies reached 90% and both total N and total P removal efficiency were 65% -70% after day 70.

关 键 词：好氧颗粒污泥 CA^2+ ZETA电位 序批式生物反应器 去除率 

分 类 号：X522[环境科学与工程—环境工程]