Mechanochemical degradation of aromatic sulfonic acids.

Sulfonic acids and sulfonates are widely used as surfactants in various industrial processes. Although partial biodegradation occurs, their release in the environment has determined a widespread pollution problem due to their remarkable tendency towards accumulation. For this reason, various methodologies to effectively degrade sulfonic acids and sulfonates in real matrices are currently under investigation. In this study, we focused our attention on the mechanochemical degradation of the 1,5-naphthalene disulfonic acid using strongly reducing agents such as pure Mg and Ca metals. The mechanochemical processing induced either a gradual degradation of the organic compound or a combustion-like reaction depending upon the experimental conditions. A partial degradation of the sulfonic acid was observed as a result of gradual reactions. An almost complete removal of the pollutant was instead observed after combustion-like reactions.