苏云金芽孢杆菌对PAHs的降解研究

Study on the Degradation of PAHs by Bacillus thuringiensis

为研究苏云金芽孢杆菌(Bacillus thuringiensis)在不同温度、pH、多环芳烃(PAHs)质量下对蒽芘芴的降解性能,采用单因素实验和响应面分析结合的方法,以 PAHs 为唯一碳源,活性炭为吸附载体,利用索氏提取法测定降解吸光度值。根据 Design Expert 8.0.6.1 软件中 Box-Behnken design 对实验结果进行分析。结果表明,温度与 pH 交互项对蒽、芘的降解影响显著,温度与 PAHs 质量交互对芴的降解影响显著。在优化实验中,蒽芘芴 3 物质在各自的优化条件下的降解率预期值分别为 92.13%、87.08%、83.56%,与实际试验值 91.60%、86.62%、82.95%相比,相对误差为±0.58%、±0.53%、±0.73%之间。3 个优化模型相对误差均在 2%以内,表明 3 个实验模型均可用于分析及预测苏云金芽孢杆菌对蒽芘芴的降解效果。

In order to study the performance of Bacillus thuringiensis degrading anthracene,pyrene and fluorene at different temperatures,pH and qualities of PAHs,a single factor experiment and a response surface analysis were combined,Soxhlet extraction method was applied to determine the degradation absorbance value using PAHs as the sole carbon source and activated carbon as an adsorption carrier. The experimental results were analyzed via Box-Behnken design in software Design Expert 8.0.6.1. The results showed that the interaction between temperature and pH presented significant effects on the degradation of anthracene and pyrene,and the interaction between temperature and PAHs quality significantly affected the degradation of fluorene. In the optimized experiments,the predicted degradation rates of anthracene,pyrene,and fluorene under respective optimized conditions were 92.13%,87.08%,and 83.56% respectively,the relative error between the predicted value and the actual value 91.60%,86.62%,and 82.95% were ±0.58%,±0.53%,and ±0.73%.The relative error of the three optimization models were all within 2%,indicating that the three experimental models could be used to analyze and predict the degradation effect of B. thuringiensis for anthracene,pyrene,and fluorene.