I am currently working with biofilms to remove P and carry out nitrification within aquatic systems. We are currently trying to chose a biofilm media to support the growth of healthy biofilms, which is proving more difficult than we originally thought.
Here is our criteria:
- Must have very high SSA (specific surface area)
- Must be chemically inert (i.e., not alter pH or release any chemicals into the water).
- Must be relatively easy to get hold of in large volumes.
- Must be relatively cheap to purchase.
We are ideally looking for porous beads, but are having difficulty finding ones that may be usable.
Any tips/advice/help would be much appreciated.
Cheers,
Jack
Hi Jack,
I would suggest to purchase dome carrier material from an aquarium shop. These have SSA of up to 100m2/m3, made of polypropylene and are quite cheap. If you type in google: "random packing material" you should be able to find what you are looking for.
Good luck,
In the wastewater industry the leading supplier is AnoxKaldnes from Lund, Sweden (http://www.anoxkaldnes.com/). They have polyethylene carriers with effective specific areas from 100-500 m2/m3. As this company is a subsidiary of Veolia it is always possible to find a local contact for their products.
Thanks, guys. Are any of you aware of a more bead-like structure? Ideally porous? we have a feeling that the ones that you suggested may be difficult to clean/back wash. Is this the case?
Thanks!
Jack
Hi Jack,
we have had a lot of success with Lee's biopinballs , available from aquarium suppliers. I can forward some references if you are interested. Cheers
Darren
The media I suggested is intended to be used in suspension. Look up MBBR. This is much more cost and size effective than building a filter. With suspended biofilm you do not have the need to backwash as the movement continuously scrape the excess biofilm from the surfaces.
It sounds like you intend to make a trickling filter type of treatment, but this is regarded as outdated in the wastewater treatment industry and they are rarely constructed anymore. The problem is mainly the stability of treatment performance and the high energy cost for nitrification.
Dear Jack,
I am not sure what water (composition) you have in mind and whether periodic washing of porous material is needed (e.g. to remove accumulated material).. During treatment for drinking water production often activated carbon (porous) and/or sand are used for filtration. These materials seem to match your criteria.
Best regards, Hans
