Abstract: Pseudomonas sp. QG6, which could utilize quinoline as sole carbon and nitrogen source, was isolated from industrial wastewater. The best conditions for simultaneously biodegrading quinoline and removing phosphorus were optimized through orthogonal experiment. Strain QG6 displayed excellent capability of biodegrading quinoline, i.e., the biodegradation process could be completed in 12 hours with initial quinoline concentration of 96?144 mg/L. With organic carbon as carbon source, inorganic nitrogen as nitrogen source and no quinoline added, the removal efficiency of 8.69?19.41 mg/L of phosphate could reach 86% in 20 hours, suggesting strain QG6 displayed perfect phosphate removal in aerobic condition. With no external organic carbon source added, the simultaneous phosphate removal efficiency of 10 mg/L was only 33% though the degradation of quinoline (C/N=7:1) with initial concentration of 144 mg/L showed little decrease. Adding external organic carbon source to initial C/N of 20:1 significantly improved phosphorus removal when simultaneously degrading quinoline, i.e., the removal efficiency of phosphate significantly increased up to 86%. Results of orthogonal experiment display that with degree of external carbon source, the optimum pH, temperature (T), rotation speed of shaking table (S) and initial concentration of quinoline (C0) in order of importance are C0=200 mg/L, T=25°C, pH=8 and S=120 rpm for quinoline degradation; and S=100 rpm, T=25°C, C0=150 mg/L and pH=9 for phosphate removal, respectively.

Key words: strain QG6, quinoline biodegradation, phosphate removal, orthogonal experiment

摘要： 从工业废水处理系统中分离出一株以喹啉为唯一碳源和氮源的假单胞菌QG6 (Pseudomonas sp. QG6), 用于喹啉降解同步除磷, 并采用正交实验设计优化出最佳条件。菌株QG6具有较好的喹啉降解能力, 12小时内能将96~144 mg/L的喹啉完全降解。菌株QG6在好氧条件下具有除磷能力, 不存在喹啉的条件下, 以有机碳为碳源、无机氮为氮源、初始磷酸盐浓度为8.69~19.41 mg/L时, 20小时内能去除磷酸盐86%以上。初始喹啉浓度为144 mg/L (其自身的碳氮比约7:1)、磷酸盐浓度为10 mg/L时, 若不外加有机碳源, 喹啉在12小时内被降解完全, 同一时段内除磷率仅为33%。外加有机碳源至碳氮比20:1且其他条件都相同时, 喹啉降解 效果不受影响, 且同步除磷率提高到 86%。正交实验表明, 外加碳源条件下喹啉降解的最佳条件按影响大小排列为: 初始喹啉浓度200 mg/L, 温度25°C, pH 8, 摇床转速120 rpm; 除磷最佳条件为: 摇床转速100 rpm, 温度为25°C, 初始喹啉浓度150 mg/L, pH 9。

关键词: Pseudomonassp.QG6, 喹啉降解, 除磷, 正交试验