常低温下EGSB处理生活污水的影响因素研究

在15～26℃的常低温条件下,采用EGSB处理生活污水,考察了进水流量、回流比、液体上升流速(Vup)、温度等因素对运行效果的影响。结果表明,当温度为26℃左右时,对于9～11 L/h的低进水流量,宜采用高回流比(1.6～2.5),对COD的去除率最高可达90%;对于15～24L/h的高进水流量,宜采用低回流比(0～0.6),对COD的去除率最高可达84%;当进水流量提高至30 L/h时,不宜回流,对COD的去除率降至77%;当进水流量分别为9、11、15、24、30 L/h时,最佳Vup分别为4.0、(3.1～3.6)、(2.7～3.4)、3.0和3.8 m/h,此时对COD的去除率分别高达90%、(87%～89%)、(83%～84%)、83%和77%;在无回流的条件下,适宜的进水流量为15～24 L/h,相应的HRT为0.5～0.8 h。当温度为15～26℃时,EGSB适宜的运行条件是高进水流量(15～24L/h)、高Vup(3.0 m/h)和低回流比(0～0.6),此时对COD的去除率高达81.9%以上。

Influencing Factors of Domestic Sewage Treatment by EGSB at Ambient and Low Temperature

EGSB was used to treat domestic sewage at 15 to 26 ℃. The effects of influent flow, recycle ratio, liquid up-flow velocity (V_(up)) and temperature on the treatment efficiency were investigated. The results show that at around 26 ℃, high recycle ratio of 1.6 to 2.5 and low influent flow of 9 to 11 L/h result in the highest COD removal rate of 90% while low recycle ratio of 0 to 0.6 and high influent flow of 15 to 24 L/h lead to the highest COD removal rate of 84%. When the influent flow increases to 30 L/h, any recycle flow is not suitable and the COD removal rate decreases to 77%. For the varied influent flows of 9, 11, 15, 24 and 30 L/h, the optimal V_(up) is 4.0, 3.1 to 3.6, 2.7 to 3.4, 3.0 and 3.8 m/h, and COD removal rates are 90%, 87% to 89%, 83% to 84%, 83% and 77%, respectively. The optimal influent flow and HRT are 15 to 24 L/h and 0.5 to 0.8 h without recycle flow. At 15 to 26 ℃, the optimal operation conditions of the EGSB are influent flow of 15 to 24 L/h, V_(up) of 3.0 m/h and recycle ratio of 0 to 0.6. A COD removal rate of above 81.9% can be attained.