Question

2.Mr. Green water his lawn with reclaimed water from the local wastewater utility. The reclaimed water has 10 ppm total nitrogen. He irrigates his lawn at 1.0 inch of water (from the reclaimed water) per week each year. (Assume 1 acre of lawn) .

A. How many inches of reclaimed water does he use each year?

B.How many pounds of Nitrogen are there per 1 million pounds of reclaimed water are there in this reclaimed water?

C.How many pounds of nitrogen is he applying to his lawn each week just through the use of this reclaimed water?

Answer 1

A)

given

1 inch of water per week

now

1 year = 52.1429 weeks

so

total amount of water per year = 1 x 52.1429

total amount of water per year = 52.1429

so

52.1429 inches of reclaimed water each year

B)

we know that

ppm = 1 unit of nitrogen / 10^6 units of water

10^6 = million

given

10 ppm

so

there will be

10 units of nitrogen in 1 million units of water

so

10 pounds of nitrogen in 1 million pounds of water

C)

we know that

1 acre = 6.273 x 10^6 square inch

also

1 inch of water = 0.03613 pound / square inch

given

1 inch of water each week

so

amount of water each week = 0.03613 x 6.273 x 10^6

so

amount of water = 0.22664 x 10^6 pound

amount of water = 0.22664 million pounds

now

1 million pound water ---> 10 pounds Nitrogen

0.22664 million pound water ---> y

y = 10 x 0.2266

y = 2.266

so

2.266 pounds of nitrogen is applied each week