Fe2+、Co2+、Ni2+对渗滤液厌氧过程的影响

通过单因素和正交试验,分别研究了Fe2+、Co2+、Ni2+及其组合对渗滤液厌氧过程中COD去除率和产甲烷量的影响.结果表明,分别投加Fe2+=25 mg·L-1、Co2+=1 mg·L-1、Ni2+=0.5 mg·L-1时对COD去除率和产甲烷量促进显著,3种微量元素均表现出了"低促高抑"的Hormesis效应.微量元素组合投加时,协同促进了甲烷的产生,其中Co2+是影响COD去除率的主要因素,Fe2+是影响产甲烷量的主要因素,但3种微量元素在其各自适宜的投加浓度范围时,对渗滤液厌氧过程的促进效果较为相近.各试验组的pH值维持在7.05~7.53之间,并与产甲烷量呈显著的相关关系.此外,渗滤液成分复杂,微量元素的生物有效性一定程度上受到限制,渗滤液厌氧体系对微量元素的需求较别的体系偏高.

Effects of Fe2+,Co2+ and Ni2+ on anaerobic process for landfill leachate treatment

Single-factor and orthogonal batch assays were conducted to investigate the effects of Fe²⁺,Co²⁺ and Ni ²⁺ and their combinations on COD removal efficiency and methane yield in the anaerobic treatment of landfill leachate.Results indicated that at low concentrations,Fe²⁺ of 25 mg·L^-1,Co²⁺ of 1 mg·L^-1 and Ni²⁺ of 0.5mg·L ^-1 significantly increased the COD removal efficiency and methane yield,inducing a Hormesis effect (defined as a stimula-tory effect of sub-inhibitory concentrations of toxic substances).The combinations of the three ions showed a synergistic effect on methane yield.Though similar stimulations of the each micronutrients in its own suitable dosages were observed.Co²⁺ markedly enhanced the COD removal and Fe²⁺ increased the methane yield on landfill leachate treatment.The pH values that maintained almost constantly between 7.05~7.53 was correlated significantly with methane yield.The biological effectiveness of micronutrients was inhibited by various ligands in landfill leachate,resulting in slightly higher requirement of micronutrients compared with other literatures.