This work investigated the potential of various natural, modified, and synthetic adsorbent materials for the removal of both cationic (e.g., NH4+) and anionic (e.g., PO43-) nutrients from contaminated waste streams. Among all the studied adsorbents, a commercially available synthetic adsorbent, namely Umix, with 101.6 mg total-P/g, and natural clinoptilolite (NZ) with 17.9 mg total-N/g adsorption capacities demonstrated the best performances in capturing phosphorous-P and nitrogen-N species from aqueous solutions. Zirconium-modified clay (ZrC) also showed a high capacity in adsorbing P species, and eventually, two adsorbent mixtures, including ‘ZrC+NZ’ and ‘Umix+NZ’ were selected for exploring the simultaneous removal of N and P species from bisolute solutions. The effect of various operational parameters, including adsorbent dosage, solution pH, initial nutrient concentrations, and contact time were studied. In an optimum adsorbent (g): solution (ml) loading ratio of 1:300 for ZrC and Umix, and 1:60 for NZ, with 24 h contact time, and using a synthetic NH4-PO4 solution with concentration and pH similar to the targeted wastewater (i.e., dairy farm wastewater), we could achieve 96% total-P and 26% NH4-N removals using ‘ZrC+NZ’, and 94% total-P and 29% NH4-N removals using ‘Umix+NZ’. The pseudosecond-order kinetic model best fitted with experimental data, indicating that chemisorption was the predominant mechanism in bi-solute adsorption processes. A cross-linking reaction between sodium alginate and barium chloride fabricated granules of the powdered adsorbent mixtures. Applying 0.5 g of each of the ‘ZrC/NZ’ and ‘Umix/NZ’ granules in 30 mL of dairy farm wastewater resulted in 20% and 60% total-P and 1.3% and 13% NH4-N removals, respectively. The obtained results showed that the developed granules could be used as dual-functional adsorbent materials to remove cationic and anionic nutrients from contaminated waste streams.
