高铵氮废水生物硝化过程抑制现象初探

采用SBR反应器研究了硝化反应中氨氧化和亚硝酸氧化的抑制动力学,发现了氨氧化过程的多态现象.当自由氨浓度小于10mg·L-1时,氨氧化菌不会受到抑制,为氨氧化菌的第一个稳态阶段;当自由氨浓度大于10mg·L-1、小于50mg·L-1时,氨氧化菌受到抑制,为第一过渡阶段;当自由氨浓度大于50 mg·L-1、小于175mg·L-1时,氨氧化菌同样不受抑制,为氨氧化菌的第二稳态阶段;当自由氨浓度约大于175mg·L-1时,氨氧化再次受到抑制,直到自由氨浓度达到约750 mg·L-1,氨氧化反应才趋于停止.对于亚硝酸氧化菌,自由氨浓度1 mg·L-1为其受抑制的下限,50mg·L-1时亚硝酸氧化反应完全停止.Haldane抑制动力学方程可以较好地描述氨氧化的铵氮或自由氨基质抑制动力学过程.亚硝酸氧化的铵氮抑制过程也可较好地用Haldane抑制动力学来描述.

Inhibition of nitrification of ammonia-rich wastewater in an SBR

Ammonia oxidation and nitrite oxidation kinetics were studied using a SBR, and multiple steady states were discovered in the ammonia oxidation. Ammonia-oxidizing bacteria were not inhibited when free ammonia (FA) concentrations were below 10 mg·L-1. This is the first steady state. Ammonia-oxidizing bacteria were inhibited when FA concentrations were between 10 mg·L-1 and 50 mg·L-1, which is the first transient state. Ammonia-oxidizing bacteria were not inhibited when FA concentrations were between 50 mg·L-1 and 175 mg·L-1, the second steady state. Ammonia-oxidizing bacteria were inhibited again when FA concentrations exceeded 175 mg·L-1, and ammonia oxidation ceased when FA concentrations reached 750 mg·L-1. For the nitrite-oxidizing bacteria, the FA inhibition threshold was 1.0 mg·L-1, and the nitrite oxidation reaction ceased when FA concentrations reached about 50 mg·L-1. The inhibition kinetics of ammonia oxidation for ammonium-nitrogen or FA could be described by the Haldane inhibition equation. The ammonium inhibition kinetics of nitrite oxidation could also be described by the Haldane inhibition equation.