El Dunque is a small community in Puerto Rico. They drink surface water from the rainforest. Right now they have a chlorination contact tank followed by a 3" diameter pipe that travels 1.5 miles until the first customer. Assume that t10of the tank is 40 minutes and that Q = 0.1 ft3/sec. How much chlorine would they save if they added a sand filter (direct filtration)? Assume that they must adhere to the EPA regulations of 3-log removal of Giardia and 4-log removal of viruses. Assume T = 20° C and pH =
6.5.
First calculate the amount of chlorine required at the end of the pipe without the sand filter.
Next calculate the amount of chlorine required at the end of the pipe if a sand filter (direct filtration) is installed.
Adding a sand filter allows a saving of how many lbs of chlorine per year?