Impact of VFA Concentration of Recirculated Leachate on Stabilized Methanogenetic Landfill Layer

Organic matters in recirculated leachate could be treated by the stabilized methanogenetic landfill layer.However,high content of volatile fatty acids(VFA) in the recirculated leachate could inhibit the methanogenesis in the landfill layer,and reduce its removal efficiency for organics.Lab-scale stabilized methanogenetic landfill column,recirculated with simulated leachate,was setup and the effect of VFA mass concentration of recirculated leachate on the methanogenesis of bioreactor landfill layer studied.The results indicate that leachate with high VFA-C mass concentration could be treated by the methanogenetic landfill layer,whose capacity less than 1.0(g/(kg·d).) Methanogenesis is inhibited when the VFA-C mass concentration of recirculated more than 14.8(g/L,) with the organic loading of 2.2(g/(kg·d).) However,the inhibition could be eliminated when the VFA-C mass concentration drops to 12.0(g/L.) For the purpose of maintaining the waste degradation in the stabilized methanogenetic landfill layer,the VFA-C concentration of recirculated leachate should be less than 1.0(g/(kg·d).)