Phosphorus removal by ceramic tight ultra-filtration (CTUF) membranes for RO pre-treatment

gReverse Osmosis systems are wildly used for sea water desalination and water reclamation but they meet problems regarding bio-fouling. Bio-fouling increases their work pressure and operational costs and decreases their removal efficiencies. Phosphorus limitation is one strategy to control bio-fouling. This report focuses on phosphorus removal by ceramic tight ultra-filtration (CTUF) membranes (1kD and 3kD MWCO) as a pretreatment before RO. In this research we investigated different factors affecting phosphorus rejection by CTUF such as flux, cross flow velocity, ion strength, zeta potential and pH. The results show that increasing the flux, the cross flow velocity and the zeta potential increased the removal rate of phosphate. Increasing ion strength decreased the double layer thickness and decreased the removal rate of phosphate. All these results are in agreement with the theory of membrane filtration. The pH affected both the zeta potential of the membrane and the charge of the phosphate ion. Increasing pH increased the removal rate of phosphate but after pH 8.3, the removal rate of phosphate began to decrease. There is no explanation for this decrease in rejection at higher pH at this moment.

Subject

CTUF
phosphate removal
zeta potential
double layer thickness

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http://resolver.tudelft.nl/uuid:e80e6742-4f34-473e-80ef-e3f297aee303

Embargo date

2012-09-10

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Student theses

Document type

master thesis

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