Tests between a pure water curtain and a water curtain containing three organic acids (CH3COOH, C6H8O7 and C4H6O5) and surfactants were conducted to compare the release of ammonia in confined space. These additives are composed of different concentrations of single CH3COOH, C6H8O7, C4H6O5 solution and their pair combinations of compound additives. The results showed that the organic acids can promote the chemical decontamination effect of the water curtain on ammonia. The compound additives have better synergistic decontamination effect on ammonia. The decontamination mechanisms are physical absorption, air entrainment, physical block and chemical absorption. The addition of surfactant additive can improve the surface properties of the solution, reduce the surface tension, increase the contact area with the water curtain and ammonia, efficiently promote the physical and chemical effect of contains inorganic salt additive. The causticity of organic additives was tested and the results showed that three organic acids have faint corrosive effect on the surrounding facilities. (C) 2016 Institution of Chemical Engineers. Published by Elsevier B.V. All rights reserved.