These large ions crowd together in aqueous phase and alter the solubility of AP in that phase, finally pushing it into the organic phase. Additionally, as ammonium sulfate concentration increases, the surface tension of the system increases, leading to an increase in the interfacial tension. Higher interfacial tension generates a greater polarity difference and a higher density difference between both phases in the salt system, thus causing an increased extraction of AP in the t-butanol phase. Additionally, extraction yield decreased after 40% (w/v) ammonium sulfate concentration. High ammonium salt concentration may lead to the generation of an ammonium salt of AP, which is insoluble in t-butanol phase (Vetal et al., 2014). Therefore, optimized concentration of 40% optimized concentration of 40% ammonium sulfate was used in further TPP process.