Published by nada Belmokhtar in Academic
Category: Academic
Here are some online resources with dimensions and considerations:
https://www.sciencedirect.com/topics/engineering/sand-filter
https://www.health.state.mn.us/communities/environment/hazardous/topics/gac.html
https://www.wateronline.com/doc/drinking-water-filtration-using-granular-acti-0001
Published by Steven Cooke, President, Process Systems Consulting
thank you
Published by nada Belmokhtar
Please see the attached book - it will give you guidance.
Published by Nikolay Voutchkov, Water Globe Consulting, LLC - President
Thank you for your help
Published by nada Belmokhtar
Thank you for this Nikolay, much appreciated. It looks very comprehensive, and I will make good use of it. Ian
Published by Ian Pearson
The vendor has "Equilibrium Isotherms" for their various particle size activated carbon products. This can be based on "empty bed contact time" to calculate when there is breakthrough or the bed needs reseating. Ask your vendor for this information, if they do not have it available they might not be reputable. There also other tests for reactivity for different substances to calculate replacement intervals.
Published by John Salonich, Vice President / Managing Director
Your question is not clear, however if you are referring to normal sand filters, the depth of filter sand (excluding gravel under-drain) should be 0.8 to 1.0m depth, but could be up to 1.2m depth. Your design is related to the through-put desired, which for rapid gravity sand filters will be in the range of 4 to 8m per hour. So you filter beds must be sized accordingly, allowing additional capacity for down time during backwash operations (5 to 10%).
In terms of activated carbon columns, the situation is different in that you use the column until the granular carbon breaks through in terms of the organics you are removing - so is highly dependent on the organic load, the type of granular carbon used (and it's absorption capacity), whether you will need to backwash to remove filtered particles from time to time (or whether the input water has already been through a filter media), and your design run cycle (e.g. 1 month or 6 months). Note that granular activated carbon must be removed and replaced when spent - although it can be partly restored through thermal treatment.
If on the other hand you are referring to placing a layer of anthracite on top of the sand bed of a normal gravity filter to extend the filtration cycle, a layer of approximately 0.3 to 0.5m is recommended.
Published by Ian Pearson
I'm wondering about how to calculate the quantity of media to be fill in the colonne,Thank you for your help
Published by nada Belmokhtar
A loose estimate is 1/2 of the height of the column containing the median: you have to backwash, and expand, the media to wash away the material removed from the filtrate.
Published by Waymon Hofheins