Novel mixed matrix membranes and fibers were fabricated to investigate ammonium removal for the first time from wastewaters especially aquaculture wastewaters. Several approaches were adopted to fabricate these mixed-matrix membranes including a wet phase inversion process as well as pore filling of commercially available membranes. Natural zeolite particles were effectively incorporated into polysulfone polymer matrices. These composite materials are found to be efficient for ammonium removal with high capacity and high stability. No leaching of zeolite materials was detected. These mixed-matrix membranes demonstrate high water flux and are easy to regenerate. Over 90% of total ammonia nitrogen (TAN) can be removed from relatively low TAN concentration aquaculture wastewaters. These novel adsorptive membranes are reusable and exhibit high viability for large scale industrial applications.