The present research describes an adsorption-ultrafiltration system for wastewater pretreatment in the desalination process. The study relates to an adsorption method for cleaning a solution containing phosphate contaminants followed by recovery of the adsorbent and the adsorbed material for adequate removal or further reuse. The technology provides an efficient and cost-effective method for phosphate removal from water. A strong effect was shown of iron oxide/hydroxide (Fe3+)-based agglomerated adsorbent concentration in purified water and pH level of treated water on removal efficiency. This technique achieved a residual phosphate concentration lower than 0.1 mg/l as P, which is acceptable for wastewater pretreatment, and at least 95-98% regeneration efficiency of the phosphate with the proposed adsorbent. The phosphate adsorption capacity of the adsorption-ultrafiltration pilot-scaled system at a residual phosphate concentration of 0.1 mg/l in the solution more than one order of magnitude higher than these values reported in the literature.