Removal of tetramethyl ammonium hydroxide from synthetic liquid wastes of electronic industry through micellar enhanced ultrafiltration

In this paper, the separation of tetramethyl ammonium hydroxide (TMAH) from synthetic liquid wastes of electronic industry is carried out by using a micellar enhanced ultrafiltration (MEUF) process. This treatment represents the first step of an integrated process, aimed at the recovery of TMAH and surfactant and water reuse. The laboratory tests are carried out with an ultrafiltration module using initial solutions having a concentration of pollutant equal to 2 g/L and by adding sodium dodecyl sulfate as a surfactant, at a concentration in the range 4–10 mM/L, that is, under and above its critical micellar concentration (CMC). The experiments have been carried out at a fixed temperature of 25°C. The obtained results showed that very good percentage removals of TMAH are achieved (99%), especially when the surfactant was above the CMC.