In article <
1190983705.0...@d55g2000hsg.googlegroups.com>,
ago...@gmail.com says...
> What is the advantage and disadvantage of dosing ferric chloride to
> sewage water in activated sludge system?
>
>
We use it for phos removal and a side benifit is it helps settleability
in the secondaries. Easier to control than biological phos removal.Not
really a downside except its an additional cost. Storage and handling of
a hazardous chemical is a consideration. It will increase the pounds of
sludge you produce of course.