Kazi Sarwar Hasan, Chettiyappan Visvanathan, Prapan Ariyamethee, Sumaporn Chantaraaumporn and Pongchakas Moongkhumklang

pp. 899 - 906

Abstract

Membrane application in wastewater is gaining significant popularity. Selecting the right membrane and filtration technique is an important consideration to ensure a successful system development
and long term performance. A new type of membrane filtration technology known as ‘Vibratory Shear
Enhanced Process’ (VSEP) is introduced in this paper with some test results that has been conducted
with VSEP pilot unit to recycle starch wastewater. Conventional cross flow membrane process used in
wastewater application always led to rapid fouling. This loss in throughput capacity is primarily due to
the formation of a layer that builds up naturally on the membranes surface during the filtration process.
In addition to cutting down on the flux performance of the membrane, this boundary or gel layer acts as a secondary membrane reducing the native design selectivity of the membrane in use. This inability to
handle the buildup of solids has also limited the use of membranes to low-solids feed streams. In a VSEP
system, an additional shear wave produced by the membrane’s vibration cause solids and foulants to be
lifted off the membrane surface and remixed with the bulk material flowing through the membrane
stack. This high shear processing exposes the membrane pores for maximum throughput that is typically
between 3 to10 times the throughput of conventional cross-flow systems. The short term results with raw
starch wastewater shows very stable flux rate of 110 lmh using the VSEP system and selecting the PVDF
ultrafiltration membrane with no pre-filtration.

Keywords

• VSEP
• ultrafiltration (UF)
• membrane flux
• transmembrane pressure (TMP)
• wastewater reuse