【作者】 左漪；

【导师】 王连军；

【作者基本信息】 南京理工大学 ， 环境工程， 2008， 硕士

【摘要】 论文对特效降解菌处理苦味酸废水进行研究,从南京陶吴化工厂排污口处的泥土样品中,筛选得到一株苦味酸(学名2,4,6-三硝基苯酚,简称TNP)的特效降解菌,该菌可以苦味酸为唯一碳源、氮源、能源进行生长,经驯化之后,可在含TNP浓度高达700mg/L以上的模拟废水中生长并在35h内实现对TNP的完全降解。经16S rRNA鉴定并综合其生理生化特性,可确定该菌株为红球菌属(Rhodococcus),菌株命名为Rhodococcus sp.NJUST16。研究了温度、pH值、苦味酸浓度、NaCl浓度、额外碳源、额外氮源等因素对细菌生长及苦味酸生物降解的影响。发现Rhodococcus sp.NJUST16在温度范围20-35℃内生长,但以30℃时的降解效率最高;该菌生长以及降解TNP的效果在pH值介于7.0-7.5之间为最佳;该菌对TNP有高的耐受性,但是降解效率会随着模拟废水中TNP浓度的升高而逐渐降低;随着盐分(NaCl)浓度的升高,系统降解能力逐渐下降;此外,通过实验还发现,仅添加0.02%额外碳源时,对模拟废水中TNP的生物降解及细菌生长有明显的促进作用,最佳碳源为葡萄糖,其次是麦芽糖:而添加尿素和硝酸铵却无明显作用,但酵母膏和蛋白胨因可同时提供碳、氮源且富含多种营养成分,对细菌生长也有很好的促进效果。在上述摇床实验的基础上,采用曝气生物滤池为主体反应器,对特效降解菌Rhodococcus sp.NJUST16进行苦味酸降解的工程化研究,结果表明:“快速排菌”的挂膜方案更好;添加葡萄糖同样可以达到富集反应器内生物量的效果;运行一段时间后,系统开始具有硝化能力,可将TNP分解产生的亚硝酸盐转化为硝酸盐,提高了处理效果;曝气生物滤池可降解初始浓度达700-750mg/L的TNP模拟废水;稳定运行后,平均COD负荷可达1.41kg/m3d,平均COD去除率达76.39%。更多还原

【Abstract】 In this work,a strain was isolated from the soil contaminated by picric acid come from TaoWu chemistry in NanJing.The degradation assays suggested that strain could utilize picric acid as a sole source of carbon,nitrogen and energy.It metabolized 700mg/L picric acid within 35h.This strain identified as a member of Rhodococcus based on biochemical characterization and 16S rRNA sequence,and was named Rhodococcus sp.NJUST16.The influence of temperature,pH,concentration of picric acid,carbon source,nitrogen source and concentration of NaCl are studied in the experiment.The result show that Rhodococcus sp.NJUST16 can grow between 20-35℃,however the optimum temperature for degrading TNP is 30℃;It can grow well by the pH between 7.0-7.5.NaCl is also considered to evaluate the efficiency of TNP removal,and the result shows the efficiency of TNP decomposition of the strain descends gradually with the increase of NaCl concentration in synthetic waste water.Effect of glucose and ammonium sulphate revealed that 0.02% glucose accelerated both the degradation of picric acid and the growth of the cells,while 0.02%ammonium sulphate and urea did not.The best carbon source is glucose,and the next is maltose;The yeast paste and peptone are nutritious,they both can provide nitrogen source and carbon source which accelerated the growth of the cells too.On the basis of the above conclusions,Rhodococcus sp.NJUST16 was applied to the research of the Biological Aerated Filter(BAF.).Two start-up methods were compared.The accession of glucose can enrich the bacteria in the BAF too.The system can nitrify the nitrite to nitrate.The BAF has a high degradation value.It can degradate the synthetic waste water which concent 700-750 mg/L TNP.The average COD load is 1.4136kg/m~3d,and the removal rate of COD achieved 76.39%.更多还原