AbstractIn this study, the adsorption of the antibiotic compound tetracycline (TC) from aquaculture wastewater was investigated using lanthanum‐modified carbon nanotubes (La‐CNTs) prepared by impregnation method. The composition and morphology of La‐CNTs were characterized by EDS, XRD, and BET analysis. Single‐factor experiments were performed to investigate their effect on the adsorption of TC by La‐CNTs. The adsorption kinetics and adsorption isotherms indicated that the pseudo‐second‐order kinetic model and Langmuir adsorption isotherm equation adequately described the adsorption behavior of La‐CNTs. Moreover, the maximum adsorption capacity () was 93.46 mg/g. The thermodynamics studies indicated that adsorption of TC by La‐CNTs were endothermic and spontaneous respectively. Further, the adsorption force of La‐CNTs on TC could be attributed to van der Waals force, π–π adsorbate–adsorbent interaction and electrostatic interaction. Based on these experimental results, this novel composite material shows good potential application value for the removal of TC from aquaculture wastewater.