first 15 hrs the stack was stabilized and the product resistivity stayed around 18 m u03c9cm and product silica below 6 ppb through out the run of 700 hrs this stack feed was also subjected with contamination of toc between 220 and 440 hrs without the degradation in the product it is also seen in fig7 there is a dip in the product after 440 hrs where the bed was exhausted by design to see its ability to regenerate again and give low levels of silica and it can be seen it was able to regenerate to the original levels of quality of 18 mega ohms within a period of 15 20 hours of operation while continuing to operate with a feedstock of a conductivity of 20 u03bcs cm it was also able to deliver silica quality of less than 5 ppb the assembly was tested for 700 hours experiment 3 to confirm results on a larger assembly a 30 cell pair stack was made with the media with framework as described above the ro product was fed to an edi stack the assembly was tested for product quality and silica concentration the operating conditions were as follows feed flow 1 6 m 3 hr at 2 5 kg cm2 pressure feed conductivity in the range of 5 to 15 u03bcs cm ph of 5 5 to 6 5 feed silica of 150 to 200 ppb applied voltage 10 to 15 v p and ampere consumed 2 u2212 0 2 amps the product resistivity maintained above 18 m u03c9cm throughout the experiment the assembly was.