Exhaust air purification system for odor elimination

Cause

The exhaust air extracted from the screen building at the Ruhleben sewage treatment plant in Berlin (6,000 Nm³/h) is contaminated with hydrogen sulphide concentrations of max. 180 ppm and a relative humidity of 85 %rh. Odour emissions in the raw gas amount to 40 MGE/m³. During a preliminary planning phase, UV photo-oxidation was identified as the preferred process and commissioned for implementation with new plastic piping and new EMSR technology. The UV photo-oxidation uviblox® FOX treats odour-contaminated exhaust air containing hydrogen sulphide from the intake and lifting station of the screen building. As part of the contract, this UV photo-oxidation replaces a 3-stage old biofilter system with a downstream activated carbon air filter. This was previously dismantled.

Exhaust air treatment system uviblox® FOX

The pollutant-laden exhaust air extracted from the screen building is freed from dust particles and aerosols in a pre-filtration process. This serves in particular to protect the downstream stages and prevent contamination by solid particles or liquid droplets that burn in. The pre-filtered exhaust air then enters the UV photo-oxidation stage, where UV light of defined wavelengths is used to generate ozone, oxygen and hydroxyl radicals, which cause the pollutants in the raw gas to be reduced to less than 2 ppm hydrogen sulphide and lead to odour elimination.

A downstream residual ozone destruction stage catalytically supports the process and also prevents excess ozone from leaving the UV photo-oxidation system. The purified exhaust air is discharged into the environment via the chimney and meets the required clean gas values.

The UV photo-oxidation system was specially adapted to the customer's requirements in terms of corrosion protection, space requirements and function. This variability is mainly due to the modular and compact design of the UV photo-oxidation system.