Vortisand® System Selected for Seawater Pretreatment Desalination

Vortisand® filtration system selected to review technology as a pretreatment solution in desalination applications


The study consisted of three phases that started in the autumn of 2016 at a site located in Egypt by the Red Sea. The primary objective of pretreatment to any membrane system is to ensure the feed water is compatible with the membrane. Inadequate membrane pretreatment results in high chemical cleaning costs, increased downtime, permanent loss of performance and reduced membrane life. This is particularly true in seawater reverse osmosis (SWRO) desalination plants where water quality parameters fluctuate. High salinity can also significantly reduce the efficiency of coagulation, flocculation and dual-media filtration.

Cross-Flow Microsand Filters (CMF) consist of pressurized vessels, using fine silica sand and crossflow hydraulics to achieve high efficiency filtration. Fortex Experts put the Vortisand filtration system to the test!

The study was conducted with two side-by-side SWRO trains sharing a common open sea intake. Based on a well-documented methodology the Fortex Experts and Vortisand team had three objectives in mind;

(1) Measure the field performance of CMF in comparison with existing Multi-Media Filtration (MMF) pretreatment systems.

(2) Observe and measure the impact of two different pretreated water qualities via silt density index (SDI) and levels of turbidity.

(3) Determine the impact and ROI in relation to operating costs, water recovery, cleaning frequency, chemical consumption, power cost, feed pressure and backwash volume.

The study demonstrated that the technology of the Vortisand® Cross-Flow Microsand Filtration system made it a much more effective solution at reducing suspended solids and SDI than conventional Multi-Media Filters. With filtration rates of 3 to 4 times those of MMF systems, the Vortisand® system produced water with an SDI less than or equal to 2.4.

It appears that Crossflow Microsand Filtration is a better alternative to conventional filtration methods and has the potential to significantly reduce the life cycle costs of SWRO desalination projects. Further studies will confirm the long term technical performance and the related impact on SWRO Capital and Operating costs. The Fortex Experts and Evoqua team are excited to start working on the third stage of the three phase study; determining the impact and ROI of the high efficiency cross-flow technology.

" The program demonstrated the superior efficiency of Cross-Flow Microsand Filtration at reducing suspended solids and Silt Density Index (SDI) from seawater when compared to conventional Multi-Media Filters. "

Jean Simard, Technical Director of Fortex Experts

Review the complete white paper that was recently presented at the International Desalination World Congress! By submitting the above form you will be automatically directed to the whitepaper study. Take a deep look into the results and study, demonstrating the benefits of high efficiency cross-flow technology as a pretreatment solution in RO applications.