Issue 7, 2024

Enhanced combined sewer overflow treatment by rapid magnetic flocculation–magnetic sedimentation: efficiency and mechanism

Abstract

Magnetic flocculation has been gaining interest as a potential method for treating combined sewer overflows (CSOs) because of its short settling time, small footprint, and dense sludge. This study developed a rapid magnetic flocculation method involving 30 s rapid stirring and 90 s slow stirring combined with magnetic sedimentation to treat CSOs. Compared to traditional magnetic coagulation, the entire process had a reaction time of only 2 minutes. Despite the low floc density that was insufficient for settling by gravity alone, the flocs rapidly settled in a magnetic field due to the flocs enveloping magnetic particles, significantly reducing the required reaction and settling time for the treatment. Meanwhile, the optimal parameters of the process were determined. Under optimal conditions, the removal efficiencies of chemical oxygen demand, total nitrogen, and total phosphorus can reach 90%, 75%, and 80%, respectively. Besides, the treatment efficiency of rapid magnetic flocculation–magnetic sedimentation on CSOs under different weather conditions was also investigated to demonstrate the feasibility of the process in practical applications. The results suggest that the rapid magnetic flocculation–magnetic sedimentation technique is a promising strategy for the treatment of CSOs.

Graphical abstract: Enhanced combined sewer overflow treatment by rapid magnetic flocculation–magnetic sedimentation: efficiency and mechanism

Supplementary files

Article information

Article type
Paper
Submitted
26 Mac 2024
Accepted
07 Mei 2024
First published
07 Mei 2024

Environ. Sci.: Water Res. Technol., 2024,10, 1586-1594

Enhanced combined sewer overflow treatment by rapid magnetic flocculation–magnetic sedimentation: efficiency and mechanism

C. Xie, X. Li, Z. Tang, W. Chu and H. Li, Environ. Sci.: Water Res. Technol., 2024, 10, 1586 DOI: 10.1039/D4EW00242C

To request permission to reproduce material from this article, please go to the Copyright Clearance Center request page.

If you are an author contributing to an RSC publication, you do not need to request permission provided correct acknowledgement is given.

If you are the author of this article, you do not need to request permission to reproduce figures and diagrams provided correct acknowledgement is given. If you want to reproduce the whole article in a third-party publication (excluding your thesis/dissertation for which permission is not required) please go to the Copyright Clearance Center request page.

Read more about how to correctly acknowledge RSC content.

Social activity

Spotlight

Advertisements