微好氧条件下好氧颗粒污泥的培养

在微好氧条件下(曝气槽中溶解氧量在0．2～0．7mg／L之间)对好氧颗粒污泥的培养进行了研究．以厌氧颗粒污泥为接种污泥，考察了培养过程中厌氧污泥外观、尺寸、反应器中絮状污泥的MLSS(混合固体悬浮物)、SV(污泥体积)、SVI(污泥体积指数)和VSS(挥发性固体悬浮物)，以及颗粒化污泥体积的变化．发现培养5d后，厌氧颗粒污泥完全解体，培养10d后出现新的颗粒污泥，培养40d后污泥完全颗粒化．培养成熟的颗粒污泥呈浅褐色，粒径主要集中于500～3000μm之间，SVI达18．147mL／g，比重达1．020g／cm^3，含水率(质量分数)达95．7％，有机组分的质量分数达74．1％，沉降速率达52m／h，各项指标均优于普通活性污泥和常规曝气条件下培养的好氧颗粒污泥．

Cultivation of Aerobic Granular Sludge in Microaerobic Condition

Aerobic granular sludge was cultured in microaerobic condition, that is, with a dissolved oxygen (DO) content in the aeration vessel of 0.2 to 0.7mg/L. Anaerobic granules were chosen as the seed sludge. The variations in the appearance and size of the anaerobic sludge during the cultivation were observed, and the variations in the MLSS ( Mixed-Liquor Suspended Solid), SV ( Sludge Volume), SVI ( Sludge Volumetric Index) and VSS ( Volatile Suspended Solids) of the flocculent sludge as well as in the volume of the granular sludge were also measured. It is found that the anaerobic granules are completely disaggregated after a 5-day cultivation, that new granules are formed after a 10-day cultivation, and that the sludge in the reactor is completely granulated after 40days. It is also shown that the mature granules are sandy beige, with a diameter of 500 to 3000μm, a SVI value of 18. 147 mL/g, a specific gravity of 1. 020g/cm3, a mass fraction of the moisture of 95.7% and a mass fraction of the organic components of 74.1%, thus resulting in a settling rate of 52m/h. All these items overmatch those of the conventional activated sludge and the aerobic granular sludge cultivated in conventional aeration.