Odour monitoring and control

Detect and control unpleasant odours and prevents complaints

Offensive odours are the form of environmental pollution that generates the most complaints to authorities, although they are less recognised than other types of pollution.

Generating substances: volatile compounds containing sulphur, nitrogen or VOCs are notable for being unpleasant. Hydrogen sulphide (H2S) smells like rotten eggs; ammonia (NH3) and amines have an unpleasant odour; benzene, toluene and xylene (BTX) generate a ‘petrol smell’.

Main industrial sources: water treatment plants (H2S, NH3); paper industry (benzene, toluene, H2S); chemical industry (VOCs, mercaptans, SO2); agriculture (ammonia and amines from manure and fertilisers).

European regulation: In 2003, standard EN 13725 ‘Determination of odour concentration by dynamic olfactometry’ was introduced. The IPPC (Integrated Pollution Prevention and Control) Directive in the EU is a comprehensive regulatory framework, addressing odorous emissions through Integrated Environmental Authorisation (IEA). Facilities subject to IPPC must regularly and systematically monitor odour emissions for regulatory compliance.

Measurement: For compliance, techniques such as gas chromatography coupled with mass spectrometry (GC-MS) are used to identify odorous chemical compounds in gas samples. Chemical characterisation allows for the evaluation of compliance with regulatory limits.

Practical solutions: Portable devices such as Nanoenvi EQ measure H2S and VOCs using electrochemical cells, generating alerts when levels exceed thresholds set for corrective action. For specific requirements, Continuous Emissions Monitoring Systems (CEMS) can include instrumentation capable of monitoring NH3, H2S, TRS, SO2, BTX, CH4, and volatile organic compounds using advanced analysers.

Constant monitoring is essential to ensure environmental compliance, protect community health, and demonstrate regulatory compliance through objective data.