Stripping columns are used to remove unwanted materials from process streams. The air stripping column shown below is used to remove ammonia from water and wastewater feedstreams. This section describes various types of air stripping columns as well as steam strippers.

In a stripping column waste water with 15 mol% ammonia at 100kmol/hr will be stripped with pure air. The stripping column operates at 20^oC and 1 atm. The desired concentration of ammonia in liquid steam leaving stripping column would be 1 mol %.

1. Determine the minimum air flowrate for this tray stripping column
2. Determine the optimum air flow rate for this tray stripping column
3. Determine the actual number of stages for this stripping column if the tray efficiency is 25% (Use graphical approach)
4. Determine the ideal number of stages by Kremser equation and compare with the graphical approach

Air Outlet to Carbon or other treatment Stripper and the location of operating line and stages on the graph Equilibrium data for ammonia-air-water system TABLE 12-3. Absorption of ammonia in water