TIANHaicheng,LIULu,FANDan,et al.Design Points of Double-membrane Process in High-quality Reuse of Urban Sewage[J].China Water & Wastewater,2026,42(4):61-68.
Design Points of Double-membrane Process in High-quality Reuse of Urban Sewage
China Water & Wastewater[ISSN:1000-4062/CN:12-1073/TU]
volume:
第42卷
Number:
第4期
Page:
61-68
Column:
Date of publication:
2026-02-17
- Keywords:
- urban sewage; double-membrane process; high-quality reuse; ultrafiltration; reverse osmosis
- Abstract:
- In the context of promoting the resource utilization of sewage, the double-membrane process centered on “ultrafiltration + reverse osmosis” has been widely applied in the field of high-quality reuse of urban sewage. Combining the water quality characteristics of high concentrations of organic matter, inorganic substances (nitrogen, phosphorus), and microorganisms in urban sewage, the design key points are summarized from the aspects of pretreatment, ultrafiltration, reverse osmosis, and the treatment of concentrated wastewater generated by ultrafiltration and reverse osmosis, providing a reference for similar engineering designs. The pretreatment section should be equipped with media filtration units to reduce inorganic pollutants such as SS, iron and manganese, while enhancing sterilization to mitigate microbial contamination. The design average flux of the ultrafiltration section should not be set too high, and the head of the feed pump should be determined based on the maximum transmembrane pressure difference at the lowest temperature, so as to ensure the filtration capacity of the ultrafiltration section during cold winter periods. The reverse osmosis section should employ anti-pollution membrane elements to cope with organic pollution, and adopt an one-stage two-section configuration to achieve a target water recovery rate of 70% to 80%. During operation, the formation of insoluble salts such as calcium carbonate is controlled by acid dosing and scale inhibitor addition. When the concentrated wastewater produced by the double-membrane process is recycled back to the pretreatment section for cyclic treatment, the treatment capacity of the biochemical and advanced treatment units must be re-evaluated, and the impact of increased salinity due to concentrate recycling on both the biochemical system and the reverse osmosis section should be taken into account.
Last Update:
2026-02-17