镧、铈对厌氧颗粒污泥产甲烷的Hormesis效应及其动力学研究

间歇培养条件下研究了单一稀土元素镧(La3 )和铈(Ce3 )在不同浓度水平下对厌氧颗粒污泥活性及其动力学行为的影响.结果表明,La3 和Ce3 对厌氧颗粒污泥比产甲烷活性有促进作用的浓度范围均为0.01～0.1 mg·L-1,促进作用浓度峰值均为0.05mg·L-1,最大促进百分比分别为10.35%和20.79%;La3 和Ce3 对SMA(比甲烷活性)的半抑制浓度分别为5mg·L-1和1000mg·L-1,La3 较易对污泥产生抑制作用.米-门方程可以用来描述厌氧消化过程中甲烷发酵阶段的动力学行为,稀土元素La3 和Ce3 投加至反应系统后,提高了甲烷发酵过程的动力学常数Vmax和半饱和常数Ks.

Hormesis of lanthanum and cerium on methanogenesis of anaerobic granular sludge and its kinetics

Batch experiments were conducted to investigate the effects of the rare earth ions La3+ and Ce3+ on the activity of anaerobic granular sludge and the kinetics of anaerobic digestion. The results showed that both of the ions can promote the Specific Methanogenic Activity (SMA) at concentrations from 0.01 to 0.1 mg·L-1 with a maximum promotion of 10.35% for La3+ and 20.79% for Ce3+. The EC50 concentrations were 5 mg·L-1 for La3+ and 1000 mg·L-1 for Ce3+, so La3+ is a stronger suppressant. The Michaelis-Menten model could be used to describe the kinetic behavior of the methane fermentation phase in anaerobic digestion. Addition of La3+ and Ce3+ increased the kinetic constants Vmax and Ks.