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 (9): 2483-2496.DOI: 10.1016/j.cjche.2020.03.022

• Materials and Product Engineering • 上一篇    下一篇

Influence of flocculant polyacrylamide on concentration of titanium white waste acid by direct contact membrane distillation

Biao Hu1, Jintao Ouyang1, Lanying Jiang1,2,3   

  1. 1 School of Metallurgy and Environment, Central South University, Changsha 410083, China;
    2 National Engineering Research Center for Control & Treatment of Heavy Metal Pollution, Changsha 410083, China;
    3 Key Laboratory of Hunan Province for Water Environment and Agriculture Product Safety, Changsha 410083, China
  • 收稿日期:2019-08-26 修回日期:2020-03-05 出版日期:2020-09-28 发布日期:2020-10-21
  • 通讯作者: Lanying Jiang
  • 基金资助:
    The authors would like to thank National Natural Science Foundation of China (21176265), Hunan Provincial Science and Technology Department (2014GK3106) and Chinese National Project for Overseas Experts in Culture, Education and Public Health.

Influence of flocculant polyacrylamide on concentration of titanium white waste acid by direct contact membrane distillation

Biao Hu1, Jintao Ouyang1, Lanying Jiang1,2,3   

  1. 1 School of Metallurgy and Environment, Central South University, Changsha 410083, China;
    2 National Engineering Research Center for Control & Treatment of Heavy Metal Pollution, Changsha 410083, China;
    3 Key Laboratory of Hunan Province for Water Environment and Agriculture Product Safety, Changsha 410083, China
  • Received:2019-08-26 Revised:2020-03-05 Online:2020-09-28 Published:2020-10-21
  • Contact: Lanying Jiang
  • Supported by:
    The authors would like to thank National Natural Science Foundation of China (21176265), Hunan Provincial Science and Technology Department (2014GK3106) and Chinese National Project for Overseas Experts in Culture, Education and Public Health.

摘要: Effort has been made to investigate the concentration of titanium white waste acid (TWWA) by direct contact membrane distillation (DCMD) and the focus is the influence of polyacrylamide (PAM) on membrane wetting and fouling. It was found that the presence of PAM in feed reduced membrane flux and retarded wetting development, even though its level in feed of H2SO4 solution was only 0.0002 wt%. The difference between the tests using pure water and neat PAM aqueous solution, respectively, as feed also indicated the above effect registered with PAM. AFM results showed that the addition of PAM in feed solution changed the membrane shell surface morphology. However, conclusive proof of the PAM existence in membrane cross-section and inner surface was not obtained, probably due to its low concentration in feed solution. Two approaches were tried to recover membrane flux. In comparison with operation w/o any treatment, HCl solution rinsing did not lead to obvious improvement in membrane flux recovery, while rinsing combined with gas purge has clearly delayed the degradation in acid concentration factor. Nevertheless, even the latter could not ensure long term stability. High tortuosity and low hydrophobicity of the membranes used were suggested as underlying causes and should be addressed in the future.

关键词: Acid concentration, DCMD, PAM, Wetting, Fouling

Abstract: Effort has been made to investigate the concentration of titanium white waste acid (TWWA) by direct contact membrane distillation (DCMD) and the focus is the influence of polyacrylamide (PAM) on membrane wetting and fouling. It was found that the presence of PAM in feed reduced membrane flux and retarded wetting development, even though its level in feed of H2SO4 solution was only 0.0002 wt%. The difference between the tests using pure water and neat PAM aqueous solution, respectively, as feed also indicated the above effect registered with PAM. AFM results showed that the addition of PAM in feed solution changed the membrane shell surface morphology. However, conclusive proof of the PAM existence in membrane cross-section and inner surface was not obtained, probably due to its low concentration in feed solution. Two approaches were tried to recover membrane flux. In comparison with operation w/o any treatment, HCl solution rinsing did not lead to obvious improvement in membrane flux recovery, while rinsing combined with gas purge has clearly delayed the degradation in acid concentration factor. Nevertheless, even the latter could not ensure long term stability. High tortuosity and low hydrophobicity of the membranes used were suggested as underlying causes and should be addressed in the future.

Key words: Acid concentration, DCMD, PAM, Wetting, Fouling