Alum addition for P removal
Alum addition for P removal
(OP)
We are working on a 1 mgd activated sludge plant that has a 6 month rolling average pound limit for phosphorus. No concentration limit. The plant presently meets this limit without P removal, but could in the future have to remove some P to meet compliance if flow increase. We plan to add alum into the pipe between the aeration basin and the clarifier. M&E says this is acceptable practice. The operator says we should actually have a mixing tank prior to the clarifier. He also says we should add caustic also to maintain pH. I could understand adding caustic if we were adding lots of alum but this seems excessive just take out some pounds but not have a concentration limit. Any thoughts?
Thanks
Thanks





RE: Alum addition for P removal
Increasing the pH of the system with caustic will be extremely expensive. Suggest you ask the fellow where has he does this before.
If you can get approximately 4 changes in direction, the alum will be mixed in adequately. You can also increase the flow of the carrier fluid.
RE: Alum addition for P removal