Question

Assuming a WWTP removes 1000lbs of nitrogen from the waste water stream answer the following:

A) How many pounds of oxygen are required?

B) How many pounds of alkalinity agree required?

C) About how many pounds of sCOD?

Answer 1

Ans A) In wastewater, nitrogen is present mainly in form of Ammonia (NH3).The process of removal of nitrogen is known as nitrification.It is two step process as follows:

NH3 ---> NH4---> NO2---> NO3

Stoichiometrically , 4.56 pounds of oxygen is required to remove 1 pound of nitrogen, so oxygen required for removal of 1000 lb of nitrogen :

Oxygen required = 1000 x 4.56

= 4560 lb

Ans B) 7.15 lb alkalinity required for 1lb of Nitrogen , so 1000 lb require :

1000 x 7.15

= 7150 lb alkalinity

Ans C) 1 lb of nitrogen requires 0.08 lb of sCOD so 1000 lb requires,

0.08 x 1000

= 80 lb sCOD