XUHang,WANGAo,DINGMing-mei,et al.Performance of Membrane Distillation for Treating Filter Backwash Wastewater[J].China Water & Wastewater,2024,40(9):50-55.
Performance of Membrane Distillation for Treating Filter Backwash Wastewater
China Water & Wastewater[ISSN:1000-4062/CN:12-1073/TU]
volume:
第40卷
Number:
第9期
Page:
50-55
Column:
Date of publication:
2024-05-01
- Keywords:
- membrane distillation; filter backwash wastewater; wastewater reuse; membraneflux; membrane fouling
- Abstract:
- This paper investigated the performance of membrane distillation (MD) process with hydrophobic membranes made of polyvinylidene fluoride (PVDF), polytetrafluoroethylene (PTFE) and polypropylene (PP) for treating filter backwash wastewater. The PTFE membrane showed the best performance, maintained a permeable flux of (15.2±0.8) L/(m2·h) at temperature of 60 ℃, and stably rejected 99% of inorganic ions and more than 80% of organic pollutants. In addition, the effects of different pretreatment methods and feeding modes on MD process operation were investigated from the perspective of process optimization. Coagulation and precipitation pretreatment effectively slowed down membrane fouling, and the flux of PTFE membrane only decreased by 35% during 168 h operating cycle. Compared with the continuous concentration feeding mode, the membrane flux at the initial stage of intermittent feeding mode decreased more sharply, but the flux suddenly increased every 24 h after diluting the influent, making the overall water yield 5% higher than that of continuous feeding mode. The SEM and FTIR analysis showed that the PTFE membrane fouling was attributed to inorganic salt crystallization and humic acid organic pollution.
Last Update:
2024-05-01