以低C/N比实际生活污水为处理对象,聚氨酯海绵填料为生物载体(填料填充率25%),采用逐步提高氮负荷的方式,在较短的时间内(98 d)成功启动了同步硝化反硝化(simultaneous nitrification and denitrification,SND)的序批式生物膜反应器(sequencing batch biofilm reactor,SBBR)。实时定量PCR(real-time qualitative polymerase chain reaction,real-time q PCR)结果表明系统内硝化菌得到富集。在稳定运行期间,系统对有机物及氮的去除效果良好,平均出水COD、4NH-N+、TN分别为38.28 mg·L-1、1.23 mg·L-1、8.23 mg·L-1。微生物将大部分碳源以聚羟基脂肪酸酯(poly-β-hydroxyalkanoate,PHA)的形式储存至体内,系统内3NO-N-的去除主要通过内源反硝化作用,且反硝化过程基本无2NO-N-积累,平均SND率为70.57%,TN去除率高达82.95%。由于硝化反应和反硝化反应在同一反应器内同时进行,反硝化过程产生的碱度可补充硝化过程消耗的碱度,维持系统内p H的相对稳定。此外,可以通过DO和p H的变化判断SND的进行状态,有效地控制反应时间,节省动力消耗。
Taking actual domestic wastewater(C/N = 2.6—4.1) as influent substrate and polyurethane filler as biological carrier(filling rate was 25%), the simultaneous nitrification and denitrification(SND) was achieved in sequencing batch biofilm reactor(SBBR) in a short period of time(98 d) with gradually increased nitrogen loading. The results of real-time qualitative polymerase chain reaction(q PCR) confirmed the enrichment of nitrifying bacteria in the reactor. The system had a good effect of organic matter and nitrogen removal in the formal running period. The concentration of COD, 4NH-N+ and TN of the effluent water was 38.28 mg·L-1, 1.23 mg·L-1 and 8.23 mg·L-1, respectively. Most of COD was taken up and converted to polyhydroxyalkanoate(PHA), and the storage products were used for denitrification, which removed a large amount of nitrate. The removal efficiency of TN and SND was calculated as 82.95% and 70.57%, respectively, and the 2NO-N-concentration always kept low level. Since the nitrification and denitrification reactions took place in the same reactor and conditions, the system could maintain p H in a steady conditions by that the increasing basicity in the denitrification process can complement the consuming basicity in the nitrification process. Furthermore, the reaction time can be effectively controlled and the power consumption can be decreased through the curve change of DO and p H to judge the operation status of SND.