Composite Flow Oxidation Ditch Treatment Of Municipal Wastewater

On account of the shortcomings such as the sludge sedimentation, low oxygen utilization rate while high energy consumption oxidation ditch process in the regular operation management, we proposes that set unilateral perforation aeration at the bottom of oxidation ditch to trachea aeration, in order to change the flow patterns inside the oxidation ditch to make the oxidation ditch water compound flow state. Aeration plays an important role on oxygen filling upas well as mixed action, to improve the oxidation ditch in the distribution of the sludge homogeneity and pneumatic efficiency, increase the effective depth of oxidation ditch, reduce the cover area of oxidation ditch, improve the running effect of oxidation ditch.The experiment used the inoculation method to train and domesticate the compound flow oxidation ditch. The results showed that the system can achieve stability effluent water under the condition the water temperature between8.6℃to16.2℃while the train cycle of about15days,at the same time, the removal rates of CODcr, BOD5, SS are all more than90%.The experiment studied the influence of oxygen level and rotary flow velocity to the speed. The experimental results show that the level rotary flow speed have nothing to do with flow velocity,but oxygen linear relationship was positively.As well, the experiment studied the effect of operation and effluent water in different oxygen and running state of compound flow oxidation ditch. The experiment results showed that low energy consumption and the best control conditions of the complex flow oxidation ditch:the amount of aeration34L/min, a group pushing for flow role. In the best control condition composite flow oxidation ditch CODcr, BOD5, SS water concentration sewage treatment plant at a pond oxidation ditch level2water were down by6.4%,11.9and11.3%.Experiments analyzed the effect of the aeration amount and the level of flow velocity to compound flow oxidation ditch operation. The experiment results showed that, in the experiment condition, the amount of aeration took positive correlation between relations with removal efficiency of CODcr, BOD5, SS; Level velocity take positive correlation between relations with removal efficiency of the CODcr, BOD5, SS; The amount of aeration was the important factor that effect of system of the TP and TN removal efficiency, which had negative correlation between the relationship, the change of the level of flow velocity no significant influence to removal efficiency TN and TP. When the amount of aeration raised from20L/min to34L/min, the removal rate of TP, TN fell by14.1%and9.5%respectively. The experiment also analysed the effect factors of the distribution of the sludge in the compound flow oxidation ditch. The analysis results showed that:the main effect reason of compound flow oxidation ditch sludge distribution was the amount of aeration, with the increasing amount of aeration,compound flow oxidation ditch sludge distribute more even, in the best control condition. The distribution uniformity of the compound flow oxidation ditch sludge oxidation ditch increased by58.2%than the conventional.The experiment comparative analysised the oxidation ditch aeration and push flow comprehensive energy consumption of large-scale composite flow. The analysis results showed that, the compound flow oxidation ditch can reduce43.2%off the energy consumption of push flow, while the aeration and push flow of the required comprehensive energy consumption reduced by25.3%than conventional oxidation ditch.