Benefits of Dry Scrubbing in Odour Control Application The odour caused by wastewater treatment plants is due to the emission of different gases in varying concentrations. The odour from STPs in Industrial or apartment buildings is always a nuisance, and it must be controlled. There is proven wastewater odour control equipment available that utilize different technology. Process happen in dry scrubbing is called adsorption of gases onto solids. Where porous solid particles are filled in the vessel, where odour gases are being extracted by the help of suction fans from the odour causing process tanks. Once the porous media is in touch with odour gases, the gas molecules will be adsorbed to the surface of the porous media. Mostly used and easily available porous media for this application is activated carbon, where it is having abundance of pores to capture gas molecules. Activated carbon are made from different materials, most used raw materials for activated carbon for air purification is coconut shell based, coal mined, or wood based activated carbon. Raw material is being chosen based on the application and gases or odour to be treated. Efficiency of adsorption can be improved with chemical impregnation process on the activated carbon surface. Also, selective adsorption of gas molecules also can be done with impregnated activated carbon. Wastewater odour is caused by hydrogen sulphide gases from the anaerobic reaction in the wastewater. Hydrogen sulphide causes rotten egg smell, which creates a sever odour nuisance in the surrounding.