Gases emitted from ETP

Reason

Methane (CH4)

• anaerobic decomposition of the organic matter present in sewers

Nitrous Oxide (N2O) 

• Biological Nutrient Removal (BNR) process
• Nitrification Denitrification (NDN) process

Carbon Dioxide (CO2)

• during treatment processes
• due to electricity consumption

Hydrogen Sulphide (H2S)

• anaerobic decomposition of organic matter
• from the reduction of mineral sulphites and sulphates
• highly corrosive to mechanical and electrical equipment and sewer pipelines

Volatile Organic Compounds (VOCs)

• occurs during turbulent flow and air exchange between ambient atmosphere and wastewater
• significant amounts are found in refinery and petrochemical wastewaters