Pulp & Paper Lagoon Aeration – A Necessary Evil???
Posted by: Marc Moseley
Pulp and paper mills use a lot of water, almost 17,000 gallons per ton of paper produced. Then they have to treat the water so that it can be re-introduced into our environment. Typically this is done utilizing large volume basins or lagoons.
Mill management doesn’t like these lagoons, they smell bad, they can foam a lot, they can cost a million dollars or more a year in energy and the real gorilla in the room…sooner or later management is going to have to deal with the accumulated deposition and short circuiting caused from 20-30 years of running 30+ year old vertical aeration technology.
The typical solution has been “out of sight and out of mind” until some quick (and expensive) dredging has to be done to keep sufficient residence time capacity. In this economy and with increasing environmental vigilance, this is not so easy to do any more; especially when this solution doesn’t fix the root cause of the problem.
A more viable, 21st century solution is the focused flow of horizontal directional aeration. Combined with higher oxygen transfer created by fine bubble diffuser technology, this focused flow allows the operator a portable means to gradually replace his old vertical units with horizontal units to attack areas of deposition and re-suspend it for linkage to other horizontal units for processing and movement. Ultimately all vertical aerators would be replaced with horizontal aerators to create a permanent, self conditioning and sustaining lagoon process.
Pulp and paper lagoons may be necessary evils, but they don’t have to be necessarily evil…there is a choice.
About the author: Mr. Moseley has been in pulp & paper for 30 years and with Philadelphia Mixing Solutions for over 5 years. He has a Bachelors degree from Louisiana Tech and has a shared patent pending for stock mixing.