Welcome to Taravosh Jam.
Where natural gas is available, gas stripping via the gas strip deaerators may be used. Gas stripping deaerator is packed bed—back mixing of the gas phase as a result of the high liquid to gas ratios for deaeration.
The sour water stripper is designed to remove H2Sand NH3 from process water. This process is done by contacting the sour water with stripping steam in a packed bed. The massive void volume and low-pressure drop of packing help to alleviate scaling, fouling, or foaming. Gas stripping requires that the sulfides and ammonia are both present in the gaseous form. The ideal pH for stripping H2S is below 5.for PH above 5 sulfides are primarily found in the form of ions(HS-or S-2). Efficient ammonia stripping requires a pH above 10 to prevent the formation of ammonium (NH4+) ion that cannot be stripped.
We are using a pH around 8, which allows adequate removal of both gases. Injecting caustic near the bottom of the tower improves the ammonia stripping while still allowing sulfide stripping at the top.