Cold Water Coagulation
Cold Water Coagulation
(OP)
I'm interested in discussing the experiences of people involved in using Alum as a coagulant in low temperature climates. A plant I look after suffers badly in the winter months and should 'ideally' have additional flocculation time added..but that's another story. I'd like to use a Polyaluminium chloride but cost is not on my side.
cheers.Chris
cheers.Chris





RE: Cold Water Coagulation
RE: Cold Water Coagulation
Richard A. Cornelius, P.E.
WWW.amlinereast.com
RE: Cold Water Coagulation
What I find is that the treatment works needs additional flocculation time when the water temperature drops below about 6 (celcius) but this is currently not available. Literature reviews (backed up by my own jar testing) shows that increasing the pH set point at these times is beneficial. We normally operate at 6.2 but I've suggested a rise to at least 6.8. This worked in the jar test but was mixed on the plant (probably because some Operators didn't buy into the changes and reset things before allowing the changes a chance).
Also the plant only uses alum and jar tests with a Polyaluminium chloride have produced significantly better turbidities. Again cost implications are standing in the way of this suggestion.
Interested to here anyone else's experiences.
cheers....Chris