If your MBBR operated ...
Published by Liang Qiao, Chief Process Specialist at ZJ High New Pty Ltd
If your MBBR operated correctly, the sulfide would be oxidized to sulphate. Make sure the DO setpoint in the reactor is maintained well and BOD is reduced to a low level!
If the raw water contains a lot of sulfide, it could easily controlled by adding metal ions to precipitate the sulfide, such as FeCl3, CaCO3 etc.