AOB溶解氧亲和力低于NOB条件下序批反应器中NOB淘汰的实现机制

Mechanisms of partial nitrification in sequencing batch reactor under the condition of AOB oxygen affinity lower than NOB

经精确测定AOB和NOB的溶解氧半速度常数及其他动力学参数,研究在AOB溶解氧亲和力低于NOB条件下,在序批反应器中短程硝化实现机制.测得AOB和NOB的溶解氧半速度常数分别为0.46和0.14mg O_2/L.在这种条件下,AOB的最大比生长速率高于NOB是实现短程硝化的重要特点,测得的AOB和NOB最大比生长速率分别为0.65和0.45d^(-1).两级硝化数学模拟的结果表明,在AOB的溶解氧亲和力低于NOB条件下,低溶解氧和高泥龄都不利于短程硝化实现,而较高溶解氧和低泥龄的组合条件有利于短程硝化实现.在序批反应中的实验结果验证了数学模拟结论的正确性.

The mechanisms of partial nitrification in sequencing batch reactor was studied under the condition of AOBoxygen affinity lower than NOB by calibrating the kinetic parameters of nitrification accurately.The measured DO halfsaturation constants for AOB and NOB were0.46and0.14mg O2/L respectively.Under the condition,the higher AOBspecific growth rate than NOB was an important feature for achieving partial nitrification.The AOB and NOB specificgrowth rates were measured at0.65and0.45d-1respectively.The two-step nitrification model simulation indicated thatthe low DO and high SRT(sludge retention time)conditions were detrimental for achieving partial nitrification,whichcould be more readily achieved under the combined condition of relative high DO and low SRT.The experimental resultverified the simulation results.