常温处理生活污水微氧EGSB反应器启动运行特性

Startup and Performance of Micro-aerobic EGSB Reactor Treating Actual Domestic Wastewater at Ambient Temperature

为了研究微氧膨胀颗粒污泥床(EGSB)去除生活污水中的有机物和氮、磷(N,P)营养物的快速启动和稳动运行特性,在15～26℃常温下运行EGSB反应器9个多月,对微氧EGSB反应器内颗粒污泥的培养过程以及稳定运行阶段化学需氧量(COD)、N、P的去除规律进行了研究。通过给EGSB反应器内适量曝气,为EGSB反应器内的颗粒污泥提供溶解氧以产生微氧环境,以曝气柱内的曝气速率来控制回流水中的溶解氧量。研究结果表明,在15～26℃时微氧颗粒污泥的成功培养需要近4个月。当水力停留时间(HRT)为3.9～4.8 h,进水流量为2.5～3.1 L/h,进水COD、NH3-N、总氮(TN)和总磷(TP)的质量浓度分别在213～867,26.5～72.1,31.7～81.7和3.8～17.3 mg/L范围内波动,稳定运行微氧EGSB反应器时,COD、NH3-N、TN和TP的平均去除率分别达到了93.4%,83.8%,74.7%和44.0%;出水平均浓度分别为29,10.0,14.0和4.7 mg/L,水质分别达到IA、IB、IA和Ⅲ级标准;出水浊度在6 NTU左右。微氧EGSB反应器进口处氧化还原电位宜控制在+15 mV左右。微氧使得颗粒污泥沉速降低,最小颗粒污泥沉速低至11 m/h,没有出现污泥流失。稳定运行阶段污泥中混合液悬浮固体浓度达到28 g/L左右,混合液中可挥发性悬浮固体与悬浮固体的质量比为0.74～0.77,说明微氧EGSB反应器已成功启动并稳定运行。

To obtain the rapid startup and stable operation of the micro-aerobic expanded granular sludge bed（EGSB） reactor for simultaneous removal of carbon and nutrients（N and P） treating actual domestic sewage under ambient temperature,the EGSB reactor is operated for approximately 9 months consisting of startup stage and stable operation stage for the research on the formation of micro-aerobic granules and the simultaneous removal of the COD,N,and P at ambient temperature（15～26℃）.By controlling the oxygenation rate in the aeration column,different concentrations of dissolved O2 are generated in the circulating fluid which supplies dissolved O2 to the granule sludge bed in the EGSB reactor and to generate micro-aerobic environments.The results show that it takes only about four months for the successful startup of the micro-aerobic EGSB for the treatment of actual domestic sewage under ambient temperature.About 5 months＇stable operation,the micro-aerobic EGSB reactor treating actual domestic sewage at ambient temperature（15～26℃） runs well.With 213～867,26.5～72.1,1.7～81.7 and 3.8～17.3mg/L influent COD,NH3-N,TN,and TP concentrations,gradually increasing influent flow from 2.5 to 3.1 L/h and shortening HRT from 3.9 to 4.8 h,the average removal of COD,NH3-N,TN and TP can attain 93.4%,83.8%,74.7%,and 44.0%.And the effluent COD,NH3-N,TN and TP concentration are 29,10.0,14.0 and 4.7 mg/L,respectively,which accords with the IA,IB,IA and Ⅲ distinction of the GB 18918-2002.The effluent turbidity is about 6 NTU.At the stable operation stage,the redox potential in the inlet of the micro-aerobic EGSB reactor should be kept at about ＋15 mV.At the stable operation stage the settled velocity of the granules decreases to 11 m/h.But the granules are still held in the EGSB reactor without any washout.Moreover,the micro-aerobic EGSB reactor can keep the sludge concentration about 28 g/L and the mass ratio of mixed liquor volatile suspended solids to mixed liquor suspended solids as 0.74～0.77,which means the successful startup and stable operation for the micro-aerobic EGSB reactor.