4供气量的计算选取条件:采用网状型中微孔空气扩散器;敷设于池底0.2m处;淹没水深4.0m;计算温度30℃。水中溶解氧的饱和度:(20)(30)9.17/;7.63/;ssCmgLCmgL(1)空气扩散器出口处绝对压力(Pb)531.013109.810()baPHP代入得:5351.013109.84.0101.40510baPP(2)空气离开曝气池面时,氧的百分比为E:100%tOAA21(1-E)79+21(1-E)EA—空气扩散器的氧转移效率,网状型中微孔空气扩散器,取值12%,得:100%18.43%tO21(1-0.12)79+21(1-0.12)(3)曝气池混合液中平均氧饱和度按下式计算:()()42tsbTsOCCb5P2.02610按30℃考虑,得:(30)18.437.63()8.54/42sbCmgL551.405102.02610(4)在20℃的条件下,脱氧清水的充氧量:(20)0(20()0(30200(max)[]1.0242.01.01709.17250/0.82[0.951.08.542.0]1.024205.0303/sTsbTRCRRCCRkghRRkgh))取值=0.82;=0.95;;最大时需氧量为:时,(5)曝气池平均时供气量:303(max)250100%100%6946/0.312303100%8418/0.312ssRGmhEGmhA0.3最大时供气量:(6)去除每kgBOD5的供气量:3332438.604320245.563000mkgBODmm6949空气/每立方米污水的供气量:6949空气/污水(7)系统的空气总用量:污泥回流比R为60%,提升回流污泥所需空气量为:330.6300006000/14418/mhmh824总需空气量为:8418+6000