低温胁迫下微量重金属元素对厌氧消化工艺的影响

Effect of Trace Heavy Metals on Anaerobic Digestion Process under Low Temperature Stress

文章为提高低温条件下猪粪厌氧消化产气量,应用响应面法对其厌氧消化工艺的生物强化参数进行试验优化。通过Design-Express 8.0.6.1软件的Box-Behnken中心组合试验设计,以原料产气量为响应值,研究Fe^(2+),Ni^(2+)和Co^(2+)三元素离子浓度对猪粪产气量的影响,建立相关数学模型,并对模型进行降维优化分析,最后进行试验验证。结果表明,低温条件下,Fe^(2+)和Ni^(2+)元素浓度对于猪粪产气量的影响表现为极显著。最优工艺条件是Fe^(2+)浓度为5.0 mg·L^(-1),Ni^(2+)浓度为22.5μg·L^(-1),Co^(2+)浓度为25.0μg·L^(-1)时,厌氧消化沼气的产量为572.64 mL。与预测值584.67 mL的相对误差为2.1%,所建模型能较好地优化厌氧消化工艺的生物强化参数。

In order to improve the biogas production of anaerobic digestion of pig manure at low temperature,response surface methodology was used to optimize the bio-augmentation parameters of anaerobic digestion in this paper.Based on the Box-Behnken central composite experimental design in Design-Express 8.0.6.1 software,the effect of Fe^(2+),Ni^(2+) and Co^(2+) concentration on pig manure gas production was studied with the gas production value of raw material as response value.The relevant mathematical model was established,and the model was optimized by dimension reduction analysis and finally verified by experiments.The results showed that the effect of Fe^(2+) and Ni^(2+) concentration on biogas production of pig manure was very significant at low temperature.The optimal condition were Fe^(2+) 5.0 mg·L^(-1),Ni^(2+) 22.5μg·L^(-1) and Co^(2+) 25.0μg·L^(-1),under this condition,the biogas yield was 572.64 mL.The relative error with the predicted value of 584.67 mL was 2.1%.This model can be used to optimize the bio-augmentation parameters of anaerobic digestion process.