反硝化除磷中胞内还原型辅酶Ⅰ的荧光光谱分析

Fluorescence Spectrum Analysis of Reduced Nicotinamide Adenine Dinucleotide in Microbial Cells in Denitrifying Phosphorus Removal

采用三维荧光技术对反硝化除磷工艺中微生物胞内还原型辅酶Ⅰ(NADH)进行了分析,并建立了NADH特征峰荧光强度与PO3-4-P和NO-3-N浓度变化的关系。工艺运行结果表明:进水COD和PO3-4-P分别为180 mg/L和7.5 mg/L时,厌氧反应结束后,COD降至22.3 mg/L,而PO3-4-P上升至22.4 mg/L;缺氧反应结束后,PO3-4-P和NO-3-N浓度分别由22.4 mg/L和12.1 mg/L降为0.65 mg/L和0.41 mg/L。三维荧光光谱显示:微生物胞内NADH特征峰中心位置为Ex/Em=350 nm/450 nm,NADH特征峰荧光强度在厌氧阶段由343.8增加到987.1,在缺氧阶段由987.1减少到381.8。NADH特征峰荧光强度与水中PO3-4-P和NO-3-N浓度的相关性分析结果表明:在厌氧和缺氧阶段NADH特征峰荧光强度与PO3-4-P浓度的相关系数(r2)分别达到0.909和0.916,在缺氧阶段NADH特征峰荧光强度与NO-3-N浓度的r2达到了0.921,即可以通过测定NADH的特征峰荧光强度来预测反硝化除磷工艺中PO3-4-P和NO-3-N浓度变化,为间接测定PO3-4-P和NO-3-N浓度提供了一种可行的方法。

The reduced nicotinamide adenine dinucleotide （NADH） in microbial cells in denitrif- ying phosphorus removal process was analyzed by excitation-emission matrix spectroscopy （EEMs）, and the correlations between NADH fluorescence intensity and concentrations of PO4^3- -P and NO; - N were investigated. The results showed that when the concentrations of COD and PO4^3- -P in the influent were 180 mg/L and 7.5 mg/L respectively, the concentration of COD was decreased to 22.3 mg/L, while the concentration of PO4^3- - P was increased to 22.4 mg/L at the end of anaerobic reaction. The concentra- tions of PO4^3- -P and NO3^- -N were decreased from 22.4 mg/L and 12.1 mg/L to 0.65 mg/L and 0.41mg/L respectively after anoxic reaction. The fluorescence spectra showed that the characteristic peak of NADH in microbial cells was identified at Ex/Em of 350 nm/450 nm. The fluorescence intensity of NADH was increased from 343.8 to 987.1 in anaerobic reaction, and decreased from 987.1 to 381.8 in anoxie reaction. The correlation analysis showed that the correlation parameters （r^2） between the fluores- cence intensity of NADH and concentration of PO4^3- -P in anaerobic and anoxic reaction were 0.909 and 0.916 respectively, and the correlation parameter （ r^2 ） between the fluorescence intensity of NADH and concentration NO3^- -N in anoxic reaction was 0. 921. The concentrations of PO4^3- -P and NO3^- -N could be estimated by measuring the fluorescence intensity of NADH in microbial cells, which provided a feasible method for indirectly measuring the concentrations of PO4^3- -P and NO3^- -N.