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Impact of different shapes and types of mixers on sludge dewaterability

Fitria, D, Scholz, M and Swift, GM 2013, 'Impact of different shapes and types of mixers on sludge dewaterability' , Environmental Technology, 34 (7) , pp. 931-936.

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The most significant operational cost in a treatment plant is related to the dewatering and disposal of sludge. In this research, different shapes of mixers (radial, axial, wheel, three-blade and magnetic) have been tested to assess their influence on sludge dewaterability testing. As well as the shape of mixers, different rapid mixing velocities, rapid mixing times and coagulants also have been used as test parameters. The capillary suction time (CST) test apparatus was used as a rapid measure to assess sludge dewaterability. Findings indicate that the use of magnetic stirrers leads to the lowest sludge dewaterability properties tested using the CST. The magnetic stirrer produced greater vortex and turbulence compared with other types of mixers, so rapid contact between the coagulant and the water occurred. The use of the other mixers produced similar results. However, the application of different coagulants results differently regarding the sludge dewaterability, when using different rapid mixing velocities. Different rapid mixing times did not lead to differences in the CST. During rapid mixing, Moringa oleifera produced the highest CST values followed by alum and ferric. This is likely due to the difference in sludge volume that is produced by each coagulant. Only M. oleifera produced contaminant agglomerates. In comparison, alum and ferric produced contaminant agglomerates and coagulant hydrolysis products.

Item Type: Article
Uncontrolled Keywords: capillary suction time, coagulant, geometry of mixers, rapid mixing velocity and time, turbulence
Schools: Schools > School of Computing, Science and Engineering
Schools > School of Computing, Science and Engineering > Salford Innovation Research Centre (SIRC)
Journal or Publication Title: Environmental Technology
Publisher: Taylor & Francis
Refereed: Yes
ISSN: 0959-3330
Related URLs:
Funders: Non funded research
Depositing User: Institutional Repository
Date Deposited: 16 May 2014 16:56
Last Modified: 30 Nov 2015 23:54

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