摘要
对好氧活性污泥进行驯化，并研究了丙烯酰胺的生物降解动力学持征．驯化结果表明，经过24d的驯化后，活性污泥系统能稳定降解AM，驯化活性污泥能在20h内降解90％以上的AM，是高效的丙烯酰胺降解菌群．驯化活性污泥对丙烯酰胺的降解符合一级动力学特征．活性污泥对初始浓度为160、300和500mg·L^-1浓度范围内的降解动力学方程分别为InS=-0．0881t＋5．5043，InS=-0．0692t＋6．1282．InS=-0．0468t＋6．3649，半衰期t1／1分别为7．87h，10．05h，14．87h，降解速率常数Kh随着AM浓度增加而降低，说明高浓度的AM对其生物降解有抑制作用．当pH分别为8．5，7．2，6．2，5．1时，活性污泥对初始浓度为300mg·L^-1的AM的降解动力学方程分别为InS=-0．0414t＋6．1038，InS=-0．0592t＋6．1744，InS=-0．0692t＋6．1282，InS：-0．06t＋6．1282，半衰期分别为16．74b、11．71h、10．05b．11．55b，说明弱酸性条件对AM的降解有明显的促进作用．考察温度对活性污泥降解动力学影响的研究表明，在20～35℃，随着温度的升高，活性污泥对AM的降解效率上升．不同时间段体系内NH4^＋ -N、pH和NO3^＋ -N都随着降解时间的增加逐步上升，但是达到一定时间后会下降，表明AM在降解过程中先水解，然后发生硝化反应，进而发生反硝化反应，最终AM降解成N2、CO2和H2O．
Activated sludge was acclimated to acrylamide （ AM ） and the kinetics of AM biodegradation was studied, h was demonstrated that the acclimated activated sludge could degrade AM steadily and was a high efficiency flora for degrading AM ,able to degrade more than 90% AM in 20 hours. The degradation of AM could be described by a first-order kinetics model. For AM concentrations of 160,300, anti 500 mg·L^-1 , the kinetics equations of dr.gradation were InS = -0. 0881t ＋5.5043,1nS = -0. 0692t ＋6. 1282,and InS = - 0. 0468t ＋ 6. 3649, and the t1/2 were 7.87 h, 10.05 h,and 14.87 h, respectively. The rate constant of degradation decreased as the concentration of AM increased,which showed that high concentrations of AM inhibited the biodegradation. In addition, when the concentration of AM was as 300 mg- L^-1 . and the pH of the system was 8.5,7.2,6.2, or 5.1, the kinetics equations of degradation were InS = -0. 0414t ＋6. 1038,1nS = -0. 0592t ＋6. 1744,1nS = -0. 0692t ＋6. 1282,and InS = -0.06t ＋6. 1282, and t1/2 were 16.74 h, 11.71 h, 10.05 h and 11.55 h, which demonstrated that weak acid conditions could promote the biodegradation more effectively than weak alkaline conditions. The results also demonstrated that in the range of 20 - 35℃ , the biodegradation efficiency increased as the temperature increased. The concentrations of NH4＋ -N, pH and NO~ -N first increased, hut later they decreased smoothly. During the biodegradation process, AM was first hydrolyzed, then nitrified and denitrified,and the final products were oxidized into N2, CO2 and H2O.
出处
《环境科学学报》
CAS
CSCD
北大核心
2008年第6期1074-1078,共5页
Acta Scientiae Circumstantiae
