耐盐菌和碳纳米管复合修饰氧电极的制备和应用

Preparation and Application of Oxygen Electrode Co-modified by Salt-Tolerant Bacteria and Carbon Nanotubes

研究了选自某制药厂高盐废水排污口附近土样的耐盐菌和碳纳米管复合修饰氧电极的制作方法及其用于高盐厂区废水的生物耗氧量（BOD）快速检测的性能。实验以灵敏度为指标,优化了BOD电极制作的工艺条件,确定了复合修饰氧化电极的线性响应范围及响应时间,并研究了厂区废水盐浓度对电极的影响和复合修饰电极的稳定性。实验结果表明：耐盐菌与碳纳米管的配比（1：2）和混合物固定量（30μL）,检测温度为38℃时,电极的灵敏度最佳;修饰电极对高盐药厂废水响应的线性范围为20-580mg·L^-1（R=0.9985）,响应时间不超过200s,适宜盐浓度范围为3%-12%;该复合修饰电极可重复使用18次左右,且可随时更新;将修饰膜密封于4°C冰箱中保存46天仍有良好的响应;本复合修饰电极可用于长期在线监测高盐厂区废水。

A kind of salt-tolerant bacteria isolated from the sludge on the drain outlet of a pharmaceutical factory and the carbon nanotubes （CNTs） were used to co-modify an oxygen electrode used for rapid analyzing the BOD of the high-salt factory wastewater. Taking the determination sensitivity as evaluation target, the optimization experiments for the preparation of the co-modified electrode were conducted. The response time and linear response range of the modified electrode prepared, the effect of salt concentration on the electrode and the stability of the biofilm were also determined by the experiments. The results show that the optimum preparation conditions for the co-modified electrode preparation are as follows： the ratio of salt-tolerant bacteria to carbon nanotubes is 1：2, the amount of mixture fixed on the electrode is 30 μL and the determination temperature is 38℃. The prepared co-modified electrode exhibits a linear response range of 20~580 mg BOD？L？1 for high-salt factory wastewater and the response time is no more than 200 s （R = 0.9985） when salt concentration is 3% ~12%. The modified electrode could be renewed and reused for about 18 times, and the biofilm is disposable. The biofilm sealed and stored in refrigerator at 4℃ for 46 days can still be able to respond very well to high-salt factory wastewater. The prepared co-modified electrode can be used for long-term and online monitoring the high-salt factory wastewater.