ABSTRACT

This study proposed a new ethanol-lactic type fermentation (ELTF) and explored the optimal control strategy. Using batch experiments, the effects of pH, temperature and organic loading (OL) on ELTF were investigated. The sum of ethanol and lactic acid yield was highest at whole-control pH value of 4.0, 35°C temperature and OL of 33 gCOD/L. To improve ELTF, the dynamic pH control in the long-term CSTR was adjusted at 4.0 (1–28 days), 5.0 (29–44 days) and 4.0 (46–62 days) successively. The high concentration of ethanol and lactic acid was 8190.5 mg/L at 16th day of pH 4.0. At pH of 5.0, the average acidogenesis rate and total concentration of fermentation products increased 111.0% and 128.0%, respectively. Organisms of Lactobacillus and Bifidobacterium were the predominant bacteria in reactor. It can achieve the directional regulation of ELTF and provides parameter support for the application of two-phase anaerobic digestion.

摘要

本研究提出了一种新的乙醇-乳酸型发酵（ELTF）并探索了最优控制策略。使用批量实验，研究了 pH 值、温度和有机负载 (OL) 对 ELTF 的影响。在全对照pH值为4.0、温度35°C和OL为33 gCOD/L时，乙醇和乳酸的总和最高。为了提高 ELTF，长期 CSTR 中的动态 pH 控制依次调整为 4.0（1-28 天）、5.0（29-44 天）和 4.0（46-62 天）。在 pH 4.0 的第 16 天，乙醇和乳酸的高浓度为 8190.5 mg/L。在 pH 值为 5.0 时，发酵产物的平均产酸率和总浓度分别增加了 111.0% 和 128.0%。乳酸杆菌和双歧杆菌的生物是反应器中的主要细菌。可实现ELTF的定向调节，为两相厌氧消化的应用提供参数支持。