Liquid Polymer Feed Problem solution

Let's reason out this one.  How many gallons would be 1 ppm for a 5MGD flow?  5gallons in 5 million gallons is one ppm, RIGHT?  So half that would be 0.5 ppm.  So, 2.5 gallons of liquid polymer in a 5 million gallon daily flow will be a 0.5 ppm dosage.

If 2.5 gallons are used each day then 55gallons (1 drum)/2.5 gallons per day will give us the number of days the drum will last.  The drum will last 22 days.

Did you get this answer?  Bill

Feeding liquid polymer

Many water treatment plants use liquid polymers for coagulation or filter aids.  The liquid polymer is delivered in drums and often the polymer is fed directly from the drum using a chemical feed pump.  Most operators calculate the dosage based on the amount of liquid fed into the water flow.  In other words, the liquid polymer in the drum is considered 100% strength.  This is convenient for keeping track of the volume used so that the necessary inventory is kept on hand.

Example problem:  A treatment plant is processing 5 MGD.  It is using a liquid polymer as a filter aid and this chemical is being fed to the filter influent so the entire flow is treated.  The filter aid dosage is 0.5 ppm.  How many gallons of filter aid are used each day?  How long will a 55 gal drum last?

Work on this and I'll give the solution in the next post.

Bill