嗜麦芽寡养单胞菌株对焦化废水中多环芳烃萘蒽的降解特性

Degradation characteristics of polycyclic aromatic hydrocarbons-naphthalene and anthracene in coking wastewater by Stenotrophomonas maltophilia JWJ-Y6

生物降解是去除多环芳烃的有效方法之一,但仍存在降解不彻底、降解性能不稳定等问题,需采用细菌对其去除效果进行进一步研究。通过柠檬酸钠的共代谢作用强化嗜麦芽寡养单胞菌株(Stenotrophomonas maltophilia)JWJ-Y6对萘和蒽的降解效果研究,可为生物法降解焦化废水提供新的理论依据和数据支撑。JWJ-Y6降解萘的优化条件选择以柠檬酸钠为共代谢碳源、碳氮比2∶1、pH为8.0,与优化前相比,在此优化条件下JWJ-Y6能够在144 h内完全降解100 mg/L的萘,降解时间缩短了24 h;在168 h内对40 mg/L蒽的降解率为77.04%,提高了7.73%。在处理焦化废水方面,JWJ-Y6以柠檬酸钠为共代谢基质,对COD和蒽的降解率分别为77.28%和97.35%。JWJ-Y6降解萘和蒽的代谢途径均为邻苯二甲酸途径。JWJ-Y6降解焦化废水、JWJ-Y6与柠檬酸钠共代谢降解焦化废水、干菌剂与柠檬酸钠共代谢降解焦化废水3种情况都符合二级动力学模型。

Biodegradation is an effective method for the removal of polycyclic aromatic hydrocarbons,but there are still problems such as incomplete degradation and unstable degradation performance,further research on the effectiveness of bacterial removal is needed.In this study,the co-metabolic action of sodium citrate enhanced the degradation effect of Stenotrophomonas maltophilia JWJ-Y6 on naphthalene and anthracene.It provided new theoretical basis and data support for the biodegradation of coking wastewater.The optimal conditions for the degradation of naphthalene by the JWJ-Y6 were as follows:sodium citrate was used as the co-metabolic carbon source,the carbon-nitrogen ratio was 2∶1,and the pH was 8.0.Compared to before optimization,under above same conditions,the JWJ-Y6 could completely degrade naphthalene at an initial concentration of 100 mg/L at 144 h,the degradation time was shortened by 24 h;the degradation efficiency of anthracene at an initial concentration of 40 mg/L was 77.04%at 168 h,the degradation efficiency increased by 7.73%.In the treatment of coking wastewater,the JWJ-Y6 used sodium citrate as the co-metabolic substrate,and the degradation efficiencies of COD and anthracene were 77.28%and 97.35%.The metabolic pathways of the JWJ-Y6 for the degradation of naphthalene and anthracene were phthalic acid pathways.The degradation of coking wastewater by the three ways(the JWJ-Y6,the co-metabolic action of JWJ-Y6 and sodium citrate,and the co-metabolic action of dried bacteria agents and sodium citrate)was all in line with the second-order kinetic model.