一株Acinetobacter johnsonii的部分反硝化特性及动力学研究

从实验室A²/O小试设备中分离纯化出一株具有高亚硝酸盐氮（NO₂^--N）积累率的反硝化菌株ZY04，经过16SrDNA鉴定和基因比对后，初步鉴定为Acinetobacter johnsonii.使用Logistic模型可以很理想地拟合菌株ZY04的生长特性曲线，得到生长方程常数a=0.6588，b=24.08，k=0.2413.在维持初始基质中硝酸盐氮（NO₃^--N）浓度为100mg/L的条件下，改变碳源乙酸钠的浓度，使碳氮比（TOC/TN）为3.5，4.5，5.5，6.5，研究菌株ZY04部分反硝化性能，发现该菌株在不同碳氮比条件下均能够保持95%以上的NO₃^--N降解率，在碳氮比为3.5和4.5时，17h后NO₂^--N积累率达到70%以上；在碳氮比为5.5和6.5时，NO₂^--N积累率在更快的11h后达到85%以上，碳氮比为5.5时达到最高NO₂^--N积累率91%.使用Aiba，Edwards和Andrews模型对菌株的基质抑制动力学进行拟合，结果表明，3种模型均可以很好的拟合NO₃^--N和乙酸钠对菌株的单基质抑制动力学，在双基质抑制的9种组合中，有6种模型成功拟合了NO₃^--N和乙酸钠对菌株的双基质抑制动力学，得到了相关半饱和参数和基质抑制参数，相关系数（R²）可以达到98%.

Partial denitrification characteristics and kinetics of a strain of Acinetobacter johnsonii

A denitrifying strain ZY04 with high nitrite-accumulating rate was isolated and purified from activated sludge in lab-scale A²/O reactor. The strain was characterized and identified as Acinetobacter johnsonii by 16S rDNA phylogenetic analysis. The Logistic model were fitted well to the experimental growth curve of strain ZY04 with the growth equation constants of a=0.6588, b=24.08, k=0.2413. To investigate the partial denitrification performance of strain ZY04, the batch experiments were conducted by fixing the initial concentration at 100mg/L and supplying with different quantities of sodium acetate to control the carbon-nitrogen ratio (TOC/TN) at 3.5, 4.5, 5.5, 6.5. The result showed that ZY04 exhibited the high removal rate of nitrate over 95% under different TOC/TN conditions. The nitrite accumulation rate reached over 70% within 17 hours under the TOC/TN at 3.5 and 4.5, while the rate was over 85% within 11hours under the condition with the TOC/TN at 5.5 and 6.5. the highest nitrite accumulation rate was up to 91% when the TOC/TN was set as 5.5. The results of inhibitory kinetics analysis revealed that three biokinetic models (Aiba, Edwards and Andrews) could well simulate the growth pattern of strain ZY04inhibited by single substrate (nitrate or sodium acetate). In the double-substrate inhibitory model, six models of nine combinations successfully fitted the growth characteristic of strain affected by double substrate of nitrate and sodium acetate. The relevant semi-saturation parameters and substrate inhibition parameters were obtained, and the correlation coefficient (R²) could reach 98%.