基于针铁矿强化乙酸产甲烷过程的ADM1模型修正与模拟研究

为探究针铁矿对乙酸产甲烷途径的调控作用，利用ADM1模型（厌氧消化1号模型）对添加针铁矿的产甲烷过程进行模拟研究.首先引入氧化还原介质作为新变量，模拟SAO（syntrophic acetate oxidation，互营乙酸氧化）过程中的种间电子转移，进而建立包含DIET（direct interspecies electron transfer，直接种间电子传递）产甲烷过程的ADM1修正模型，最后利用该模型对各产甲烷途径的贡献进行评价.结果表明:①c（乙酸）分别为12和20 mmol/L时，添加40~2 000 mg/L针铁矿明显提高了乙酸体系的产甲烷速率.②修正的ADM1模型能够有效地模拟针铁矿强化乙酸产甲烷过程.③12、20 mmol/L乙酸体系的敏感性参数km_Xst（最大比乙酸氧化速率）校准值分别从1.02、1.46升至1.76、2.03，km_DIET（最大比电子消耗速率）校准值分别从0.78、1.48升至2.44、3.99，表明添加针铁矿提高了互营体系的种间电子传递速率.修正的ADM1模型对各产甲烷途径贡献的计算结果显示，针铁矿对DIET过程的强化作用与其添加量呈正相关，添加2 000 mg/L针铁矿试验组c（乙酸）为12 mmol/L]中DIET和SAO产甲烷的贡献率相比对照组分别提升了117.99%和130.73%.研究显示，修正的ADM1模型能够有效地模拟针铁矿对乙酸产甲烷过程的强化作用，并且能用于评价各产甲烷途径的贡献. 

Modification and Simulation of ADM1 Model Based on Methanogenesis of Acetate Enhanced by Goethite

In order to explore the regulation of goethite on the methanogenic pathway of acetate, the goethite dosed methanogenic process was described based on the anaerobic digestion model No. 1 (ADM1). In the current research, the redox medium was introduced as a new variable to simulate inter-species electron transfer in the syntrophic acetate oxidation (SAO) process, thereby establishing an ADM1 modified model containing direct interspecies electron transfer (DIET) methanogenesis process. The modified model was used to evaluate the contribution of each methanogenesis pathway. The results showed that:(1) Adding 40-2000 mg/L goethite could significantly increase the methanogenic rate of acetate, when acetate concentration was 12 and 20 mmol/L. (2) The modified ADM1 model could effectively simulate the goethite-enhanced acetate methanogenic process. (3) The calibration values of the sensitivity parameter km_Xst (the maximum specific acetate oxidation rate) of the 12 and 20 mmol/L acetate system were increased from 1.02 and 1.46 to 1.76 and 2.03, respectively, and the calibration values of km_DIET (maximum specific electron consumption rate) were increased from 0.78 and 1.48 to 2.44 and 3.99, respectively. It showed that the addition of goethite increased the rate of interspecies electron transfer in the syntrophic system. The model calculation results for the contribution of each methanogenesis pathway showed that the promotion effects on the DIET correlated with the goethite positively. The contribution rate of DIET and SAO in the 12 mmol/L acetate experimental group with 2000 mg/L were increased 117.99% and 130.73%, respectively. The studies showed that the modified ADM1 model could effectively simulate the promotion effect of goethite on the acetate methanogenic process, and could be used to evaluate the contribution of various methanogenic pathways.