A_2N/BAF工艺中一级BAF曝气在线控制研究

RESEARCH ON THE ONLINE AERATION CONTROL IN THE PRIMARY BAF OF A_2N/BAF PROCESS

以A2N/BAF中试工艺的一级BAF为研究对象,研究了BAF在不同气水比的条件下,沿程COD、氨氮和DO的变化规律,探索了曝气在线控制DO探头的安装位置和控制规律。结果表明,沿程DO的变化呈现先升高后降低再升高的规律;COD的降解主要集中在滤料层高度为1.0 m以下的区域;氨氮的降解主要集中在滤料层高度为0.5～2.0 m;DO探头最佳安装位置在滤料层高度为1.0～1.5 m;当原水氨氮质量浓度在40 mg/L(BAF进水质量浓度在29 mg/L)以内时,DO探头装置所显示的DO质量浓度在5.2 mg/L以上,可保证出水氨氮质量浓度小于5 mg/L。

The concentration variations of COD, NH4＋-N and DO at different G/W ratio, along the primary BAF of the pilot scale A2N/BAF, were studied to confirm the installation position of DO probe and control law of the online aeration. Experimental results showed that the DO along the BAF was probed to increase firstly and then decrease and increase again at last. COD was mainly degraded at the height of less than 1.0 m, and the NH4＋-N was mainly degraded at the height between 0.5 m and 2.0 m, so the height of filter media should be more than 2.5 m. The DO probe should be installed at the height of 1.0~ 1.5 m of the filter media. When NH4＋-N concentration of raw water was below 40 mg/L （influent NH4＋-N concentration of the primary BAF was below 29 mg/L） and the value of the DO probe dex6ce was above 5.2 mg/L, the effluent NH4＋-N less than 5 mg/L could be achieved.