活性炭出水中炭附细菌解吸附机制及工况优化

Desorption mechanism and operating optimization of bacteria attached to carbon fines(BACF) in GAC process effluents

针对活性炭出水生物安全性中炭附细菌所致的难点问题,分析了细小炭粒特性对水中细菌的吸附影响和微生物吸附炭粒的微生物学及化学机制,探讨了炭附细菌的解吸附原理;并通过正交试验和对比组合实验,研发出高速离心协同解吸附剂的新方法,能够破坏炭附细菌和炭粒间的多种作用力,提高炭附细菌解吸附的效率;进一步优化了高速离心与解吸附剂组合适宜的工况.结果表明:离心工作条件为转速18×103r/min,时间5 min,温度4℃,解吸附剂组合为焦磷酸钠(质量分数为0.01%)、Tris Buffer(浓度为0.01 mol/L,pH7.0)、蛋白胨(质量分数为0.01%)、表面活性剂(浓度为1μmol/L)和乙二醇双(2-氨乙基醚)四乙酸(EGTA)(浓度为1mmol/L)时,活性炭粒的解吸附倍数达到15.1.解吸附效率提高了75.6%,基本实现炭附细菌的分离,为活性炭出水中生物颗粒控制的研究提供理论和方法.

In order to reduce the biological risk caused by bacteria attached to carbon fines（BACF）,the characteristics of carbon fine and the bio-chemical mechanism of bacteria were analyzed.Furthermore,the desorption principle of BACF were discussed.Through the orthogonal test and comparative study,a new collaborative method of high-speed centrifugation and desorption agent was developed to weaken various forces between bacteria and fines and to improve the desorption efficiency.Then the suitable conditions about high-speed centrifugation and combination of desorption agent were further optimized.The results demonstrated that desorption efficiency could be improved by 75.6%.The best desorption ratio of BACF was to 15.1 times under the optimum centrifugal conditions,which were high-speed centrifugation（18×103 r/min,5 min,4 ℃ and the solution combination（sodium pyrophosphate 0.01%;tris buffer 0.01 mol/L,pH7.0;peptone 0.01%;surface active agent 1 μmol/L;EGTA 1 mmol/L）.The bacteria were generally separated from the fines during the experiment.The results were significant in controlling the biological safety in GAC process effluents.