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;189:186-194. doi: 10.1016/j.biortech.2015.04.016. Epub 2015 Apr 8.
To solve the pollution problem of extraction wastewater in citric acid production, an integrated citric acid-methane production process was proposed. Extraction wastewater was treated through anaerobic digestion and the anaerobic digestion effluent (ADE) was recycled for the next batch of citric acid fermentation, thus eliminating wastewater discharge and reducing water consumption. Excessive Na(+) contained in ADE could significantly inhibit citric acid fermentation in recycling and was removed by electrodialysis in this paper. Electrodialysis performance was improved after pretreatment of ADE with air stripping and activated carbon adsorption to remove precipitable metal ions and pigments. Moreover, the concentrate water was recycled and mixed with feed to improve the water recovery rate above 95% in electrodialysis treatment, while the dilute water was collected for citric acid fermentation. The removal rate of Na(+) in ADE was above 95% and the citric acid production was even higher than that with tap water.
为解决柠檬酸生产中提取废水的污染问题，提出了一种柠檬酸-沼气联产工艺。通过厌氧消化处理提取废水，将厌氧消化出水（ADE）回用于下一批柠檬酸发酵，从而实现了废水零排放和耗水量的降低。ADE 中过量的 Na(+) 在回用中会显著抑制柠檬酸发酵，本文采用电渗析去除。在空气吹脱和活性炭吸附预处理 ADE 以去除可沉淀金属离子和色素后，电渗析性能得到了提高。此外，浓缩水被回收并与进料混合，以提高电渗析处理中水的回收率，超过 95%，而稀水则被收集用于柠檬酸发酵。ADE 中 Na(+) 的去除率超过 95%，柠檬酸产量甚至高于自来水。
