Crossflow microfiltration of a primary sewage effluent–solids retention efficiency and flux enhancement
✍ Scribed by Quan Gan; Stephen J Allen
- Publisher
- Wiley (John Wiley & Sons)
- Year
- 1999
- Tongue
- English
- Weight
- 114 KB
- Volume
- 74
- Category
- Article
- ISSN
- 0268-2575
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✦ Synopsis
An experimental study was carried out to evaluate ¯ux performance and solids retention ef®ciency of a ceramic membrane system in the micro®ltration (MF) of a primary municipal sewage ef¯uent. The importance of membrane pore size and MF operating conditions on the removal of suspended solids (SS) and reduction of total dissolved solids (TDS) is demonstrated. With properly de®ned membrane parameters (eg pore size) the MF process was shown as being able to produce a permeate quality better than the required EC regulatory standards concerning urban wastewater treatment for suspended and total solids reduction. The economics of the membrane process depend largely on ¯ux performance which was seriously impeded by severe membrane fouling, especially inpore adsorption/deposition of particles. The critical in¯uence of membrane fouling on the ¯ux reduction and change of solids retention characteristics of the membrane system was analysed. Two techniques were employed and evaluated in an endeavour to enhance permeate ¯ux: (i) minimisation of surface particle accumulation by employing a helically wound baf¯e installed inside the cross¯ow channel to produce a helical ¯ow pattern and vortices encompassed in secondary ¯ow, and (ii) reduction of in-pore fouling by employing an automated high frequency back¯ushing programme. Finally, this paper highlights the relationship between the ¯ux enhancement mechanism and increased soluble solids transmission rate at elevated ®ltration temperature and when the back¯ush technique was applied. The increased total dissolved solids concentration in the permeate has profound implications on how the back¯ush technique should be implemented.