Current wastewater treatment technologies struggle to remove antibiotics from wastewaters, leading to contamination of surface and groundwater. Therefore, more effective and efficient processes for removing antibiotics from water are needed. The present study reports for the first time that three widely used antibiotics (amoxicillin, ceftriaxone, cefazoline) can be successfully removed from water under ambient conditions by using aqueous carbonation of portlandite. Breakthrough curves acquired from flow-through experiments and their respective removal isotherms were mainly used to determine quantitative equilibrium parameters. In this way, the removal of antibiotics using aqueous portlandite carbonation is very efficient for amoxicillin (9.5 mg/g), followed by cefazoline (4.3 mg/g) and ceftriaxone (2.7 mg/g). In a comparison perspective, nanomagnetite-interfacial Fenton reaction is more effective in removing amoxicillin (76.5 mg/g); however, the process is slower and chemically more complex. However, both investigated methods offer promising results at the laboratory scale and are technically feasible to be implemented in conventional and/or advanced wastewater treatment plants.