SCI和EI收录∣中国化工学会会刊

中国化学工程学报 ›› 2020, Vol. 28 ›› Issue (6): 1558-1565.DOI: 10.1016/j.cjche.2020.01.019

• Separation Science and Engineering • 上一篇    下一篇

Simultaneous recovery of phosphorus and nitrogen from liquid digestate by vacuum membrane distillation with permeate fractional condensation

Boya Qiu1, Senqing Fan1, Xiaoyu Tang2, Bufan Qi3, Liangwei Deng2, Wenguo Wang2,4, Jingyun Liu1, Yuyang Wang1, Zeyi Xiao1   

  1. 1 School of Chemical Engineering, Sichuan University, Chengdu 610065, China;
    2 Biogas Institute of Ministry of Agriculture and Rural Affairs, Chengdu 610041, China;
    3 College of Pharmacy and Biological Engineering, Chengdu University, Chengdu 610106, China;
    4 Key Laboratory of Development and Application of Rural Renewable Energy, Ministry of Agriculture and Rural Affairs, Chengdu 610041, China
  • 收稿日期:2019-09-02 修回日期:2019-12-23 出版日期:2020-06-28 发布日期:2020-07-29
  • 通讯作者: Senqing Fan, Wenguo Wang
  • 基金资助:
    The present work is supported by the Fundamental Research Funds for the Central Universities (No. 20822041B4013) and Key Laboratory of Development and Application of Rural Renewable Energy, Ministry of Agriculture and Rural Affairs, China (No. 18H0491).

Simultaneous recovery of phosphorus and nitrogen from liquid digestate by vacuum membrane distillation with permeate fractional condensation

Boya Qiu1, Senqing Fan1, Xiaoyu Tang2, Bufan Qi3, Liangwei Deng2, Wenguo Wang2,4, Jingyun Liu1, Yuyang Wang1, Zeyi Xiao1   

  1. 1 School of Chemical Engineering, Sichuan University, Chengdu 610065, China;
    2 Biogas Institute of Ministry of Agriculture and Rural Affairs, Chengdu 610041, China;
    3 College of Pharmacy and Biological Engineering, Chengdu University, Chengdu 610106, China;
    4 Key Laboratory of Development and Application of Rural Renewable Energy, Ministry of Agriculture and Rural Affairs, Chengdu 610041, China
  • Received:2019-09-02 Revised:2019-12-23 Online:2020-06-28 Published:2020-07-29
  • Contact: Senqing Fan, Wenguo Wang
  • Supported by:
    The present work is supported by the Fundamental Research Funds for the Central Universities (No. 20822041B4013) and Key Laboratory of Development and Application of Rural Renewable Energy, Ministry of Agriculture and Rural Affairs, China (No. 18H0491).

摘要: A vacuum membrane distillation (VMD) process with permeate fractional condensation on membrane downstream has been developed for simultaneous recovery of phosphorus and nitrogen from liquid digestate. The polytetrafluoroethylene (PTFE) membrane flux could reach 6000 g·m-2·h-1 with the rejection efficiency of total phosphorus (TP) over 0.99, under the condition of flowrate being 120 L·h-1 and temperature being 40℃. Membrane fouling occurred with a film of organics and microorganism deposited on the surface of the membrane. Membrane flux could be reversed after the membrane was rinsed by water. Higher feed temperature and flowrate could improve the membrane flux, while hardly affect the rejection efficiency of total phosphorus. The concentration of TP could reach 1600 mg·L-1 after membrane distillation, which is about 5 times of that in initial liquid digestate. On the downstream of the membrane, some of the permeate vapor was condensed under the vacuum condition and most of water was collected here. The remaining vapor enriched with total nitrogen (TN) was compressed and pumped to the atmospheric condition to condense. The TN concentration in atmospheric condensate was as high as 7000 mg·L-1 with the process separation factor for ammonia being enhanced to 114.

关键词: Liquid digestate, Resource recovery, Vacuum membrane distillation, Permeate fractional condensation, Enhanced separation factor

Abstract: A vacuum membrane distillation (VMD) process with permeate fractional condensation on membrane downstream has been developed for simultaneous recovery of phosphorus and nitrogen from liquid digestate. The polytetrafluoroethylene (PTFE) membrane flux could reach 6000 g·m-2·h-1 with the rejection efficiency of total phosphorus (TP) over 0.99, under the condition of flowrate being 120 L·h-1 and temperature being 40℃. Membrane fouling occurred with a film of organics and microorganism deposited on the surface of the membrane. Membrane flux could be reversed after the membrane was rinsed by water. Higher feed temperature and flowrate could improve the membrane flux, while hardly affect the rejection efficiency of total phosphorus. The concentration of TP could reach 1600 mg·L-1 after membrane distillation, which is about 5 times of that in initial liquid digestate. On the downstream of the membrane, some of the permeate vapor was condensed under the vacuum condition and most of water was collected here. The remaining vapor enriched with total nitrogen (TN) was compressed and pumped to the atmospheric condition to condense. The TN concentration in atmospheric condensate was as high as 7000 mg·L-1 with the process separation factor for ammonia being enhanced to 114.

Key words: Liquid digestate, Resource recovery, Vacuum membrane distillation, Permeate fractional condensation, Enhanced separation factor