Deodorisation by Spraying of Odour Control Products
Odour nuisance has become a major environmental issue. Indeed, odours can involve a deterioration of the quality of life for people living near some industries. Various processes are available to treat the polluted gas when it can be collected and channelled, but they cannot be applied to diffuse emissions. A practical alternative solution is to reduce odours by spraying some odour masking or neutralising products. These additives can act either on Standard Odour Unit values, or on the odorous compound itself by chemical reactions, or both. Selecting the most suitable one is not obvious because whereas a great number of products are available on the market, there is a lack of information about their chemical composition and the mechanisms they use. In order to study the performances of commercial odour control products and to determine the influence of spraying parameters on their efficiency, a pilot scale spray tower has been designed. As it is important to distinguish the abatement due to the pollutant solubility in water from the specific action of the commercial products, the experiments were led with three kinds of spraying solution: tap water, a chemical neutralising solution (ie, acidic solution for basic odour compounds) and commercial solutions diluted as recommended by manufacturers. Pollutants tested have been chosen to be representative of the main families of malodorous compounds: nitrogenous (NH3…), sulphurous (H2S…), volatile fatty acids (CH3-(CH2)2-COOH), aldehydes (CH3-(CH2)2-CHO). This study allowed to obtain a representative overview of the efficiency of several commercial products facing odorous compound families.