Scrubbers (aka. Chemical Scrubbers, Gas Scrubbers) are air pollution control devices that can be used to remove some particulates and/or gases from industrial exhaust streams.
Sox Reduction in Exhaust Pollution
As exhaust gases, sulfur oxides (SOx) attract regulatory attention after NOx. China has imposed regulation on the Air Pollution Control (Marine Light Diesel) Regulation 01/04/2014.
The requirements for ships at berth or at anchor are applicable from one hour after ships are berthed to one hour before departure. Ships may use other alternative measures to reduce emissions, such as scrubbers, shore power or clean energy systems.