Water Science and Technology (Jul 2023)

High-efficiency cleaning technology and lifespan prediction for the ceramic membrane treating secondary treated effluent

  • Zongwei Lv,
  • Shoubin Zhang,
  • Wenhai Jiao,
  • Xinyi Zuo,
  • Yuanyuan Zhang,
  • Yutian Liu

DOI
https://doi.org/10.2166/wst.2023.209
Journal volume & issue
Vol. 88, no. 1
pp. 321 – 338

Abstract

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Chemical cleaning is one of the key technical means to control membrane fouling, restore membrane flux and ensure the stable operation of membrane systems. In the experiment, the six most representative chemical cleaning agents for ceramic membranes, such as sulfuric acid (H2SO4), sodium hydroxide (NaOH), sodium hypochlorite (NaClO), ethylenediaminetetraacetic acid disodium salt (EDTA-Na2), sodium dodecyl sulfate (SDS) and nonylphenol polyoxyethylene ether (OP-10), were used as research objects. The cleaning effect of the two-step combined cleaning of chemical cleaning agents on the fouled membrane was systematically investigated. Results showed that the order of the chemical cleaning agent had a significant effect on the cleaning effect. The best chemical cleaning program was determined to be NaClO first and then SDS: the fouled ceramic membrane was soaked in NaClO solution at 0.15% for 2.5 h and further soaked in SDS solution at five times its own critical micelle concentration for 2.5 h. The predicted long-term lifespan of the ceramic membranes was 4.91 years. Scanning electron microscopy–energy spectrum analysis showed that the surface roughness of the cleaned ceramic membrane was slightly higher than that of the new membrane. The contact angle was slightly lower than that of the new membrane. HIGHLIGHTS The cleaning effect of the two-step combined cleaning of chemical cleaning agents on contaminated films has been studied.; The sequence of the use of chemical cleaning agents has a greater impact on the cleaning effect.; The best chemical cleaning scheme is NaClO first and then SDS.; The long-term service life of the ceramic film is predicted to be 4.91 years.;

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