Liquid alum is usually available at a concentration of 5.4lbalum/gal. In an industrial wastewater pretreatment application, the alum feed pump delivers 88ml/min and the flow to the filter is 3000gpm....

Liquid alum is usually available at a concentration of 5.4lbalum/gal. In an industrial wastewater pretreatment application, the alum feed pump delivers 88ml/min and the flow to the filter is 3000gpm. Calculate the dose of alum in the water applied to the filter.

An advanced treatment is implemented in industrial wastewater (addition of ferric chloride, FeCl3, and polymer), the BOD is removed in primary treatment by 30–45%. Calculate the inlet BOD load in pounds per day, BOD load, and percent reduction in aeration basin, and the annual chemical cost using the data provided below:

Flow, Q =50MGD

Influent BOD = 175mg/l

FeCl3 =20mg/l at 0.012/lb

Polymer = 0.2mg/l at $1.70/lb