High throughput membrane-less water purification


Lean, M.; Seo, J.; Kole, A.; Voelkel, A. R.; Chang, N.E.; Hsieh, H. B. High throughput membrane-less water purification. Singapore International Water Week Conference; 2008 June 23-27; Singapore.


This paper describes a highly scalable fluidic technology that presents a transformative approach to the practice of conventional water treatment. Features include: a high throughput, purely fluidic, continuous flow, membrane-less, size selective method for particulate extraction; and accelerated agglomeration kinetics from mixing and transporting chemicals and raw water in confined channels. The former involves centrifugal force created in spiral flow channels to extract buoyant and denser particles, and transverse hydrodynamic forces to separate neutrally buoyant particles and nested double spirals to focus the bands for extraction. The latter results in reduced coagulant chemical dosage by 30-50% due to the narrow size distribution resulting from fluid shear effects of seed particles for agglomeration. Together, the combined effects allow for extraction of micron sized pin flocs in fluidic structures to potentially eliminate flocculation and sedimentation steps, resulting in significant savings in reduced land and chemical cost, operational overhead, and faster processing time from raw to finished water. This technology is also directly relevant to industrial water purification, waste water reclaim, cooling tower, pre-treatment for RO, and almost any instance where reduction of TSS loading prevents clogging and extends the time between cleaning for many MF and UF filtration membranes.

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