分批补料反应器中氧化乐果曲霉降解动力学的研究

Kinetics of Biodegradation of Omethoate by Aspergillus in Fed-Batch Reactor

采用分批补料培养方式,研究了葡萄糖和氧化乐果共基质体系中氧化乐果曲霉降解动力学过程。结果表明,葡萄糖浓度高有利于促进细胞生长和提高氧化乐果的降解速率;氧化乐果浓度超过320mg·L-1对曲霉生长有抑制作用;超过820mg·L-1,曲霉对氧化乐果的降解活性开始下降,表现出底物抑制效应。选择修正Monod方程底物抑制动力学通式,应用Mathcad数学工具对数据进行曲线拟合,得到了氧化乐果底物抑制降解动力学模型,其比降解速率为0.001067h-1,ks为1260,模型计算值和试验数据标准偏差为0.031。

We designed a set of Fed-Batch reactor, which could control the concentration of the substrate under a stable level. The biodegradation kinetics of omethoate by Aspergillus was studied in Fed-Batch reactor with co-substrate comprising glucose and omethoate.We studied the relationship between the concentration of glucose and growth of cell with 1 000 mg·L^-1 omethoate in the reactor. At the same time, the connection between the glucose and specific biodegradation of omethoate was discussed. The results show that glucose was the restrictive substrate to the growth of Aspergillus, and was the main factor to affect the biodegradation efficiency of omethoate by Aspergillus . The higher the concentration of glucose, the higher the cell mass and biodegradation rate of omethoate was. On the other hand, the relationship between the omethoate and growth of cellwas studied with 5g·L^-1 glucose in the reactor, in which the omethote was the sole P source. It was showed that omethoate could boost the growth of the cell after the concentration was less than 320 mg·L^-1. When the concentration of omethoate was over 320mg·L^-1, it would inhabit the growth of Aspergillus. In the same way, we found the biodegradation activity of the cell was inhabited by larger amount of omethoate. The results showed that the specific biodegradation rate of omethoate decreased when the concentration of omethoate was over 820mg·L^-1. Finally, we selected the modified Monod model to stimulate the inhabited biodegradation kinetics process of the omethoate in the reactor. The result showed that the qm was 0.001067 h^-1, the ks was 1260, with standard deviation of 0.031.