Performance and recycling studies of alkaline metal cleaners

An experimental evaluation of the metal cleaning performance of four alkali ne aqueous cleaner formulations and surfactant recovery by membrane filtrat ion from mixtures with model oil contaminants was carried out. It was found that an adequate cleaning effect might be combined with good recycling pro perties. A rapid screening procedure for metal cleaning was combined with a simple colorimetric method and COD analysis for oil removal and surfactant recovery assays, respectively. Physico-chemical characterization of deterg ents over a wide range of temperatures and concentrations showed important differences in phase separation and aggregational behaviour and correlation s with oil separation and surfactant recovery results were inferred.