The Key Laboratory of Industrial Biotechnology, Ministry of Education, School of Biotechnology, Jiangnan University, 1800 Lihu Road, Wuxi 214122, China.
The Key Laboratory of Industrial Biotechnology, Ministry of Education, School of Biotechnology, Jiangnan University, 1800 Lihu Road, Wuxi 214122, China.
Bioresour Technol. 2015 Jan;176:121-8. doi: 10.1016/j.biortech.2014.11.024. Epub 2014 Nov 15.
To solve the problem of extraction wastewater in citric acid industrial production, an improved integrated citric acid-methane production process was established in this study. Extraction wastewater was treated by anaerobic digestion and then the anaerobic digestion effluent (ADE) was stripped by air to remove ammonia. Followed by solid-liquid separation to remove metal ion precipitation, the supernatant was recycled for the next batch of citric acid fermentation, thus eliminating wastewater discharge and reducing water consumption. 130U/g glucoamylase was added to medium after inoculation and the recycling process performed for 10 batches. Fermentation time decreased by 20% in recycling and the average citric acid production (2nd-10th) was 145.9±3.4g/L, only 2.5% lower than that with tap water (149.6g/L). The average methane production was 292.3±25.1mL/g CODremoved and stable in operation. Excessive Na(+) concentration in ADE was confirmed to be the major challenge for the proposed process.
为解决柠檬酸工业生产中提取废水的问题，本研究建立了一种改进的柠檬酸-甲烷联产工艺。采用厌氧消化处理提取废水，然后用空气汽提去除废水中的氨。接着进行固液分离去除金属离子沉淀，将上清液回收用于下一批柠檬酸发酵，从而消除废水排放并减少用水量。接种后在培养基中添加 130U/g 的糖化酶，并进行 10 批的循环回收。在回收过程中，发酵时间缩短了 20%，第 2 到第 10 批的平均柠檬酸产量为 145.9±3.4g/L，仅比自来水（149.6g/L）低 2.5%。平均甲烷产量为 292.3±25.1mL/gCOD去除，运行稳定。确定 ADE 中过高的 Na(+)浓度是该工艺的主要挑战。
