scallop shell coated fe2o3 nanocomposite as an eco-friendly adsorbent for tetracycline removal

scallop shell coated fe2o3 nanocomposite as an eco-friendly adsorbent for tetracycline removal

the present study focused on the usability of scallop shell coated fe2o3 nanoparticles as an eco-friendly new absorbent in the treatment of tetracycline (tc). the process performance in terms of tc removal was investigated at different operating conditions i.e. at solution ph of 7-11, fe2o3-scallop dosage of 0.4- 2.4 g l-1, initial tc content of 20-120 mg l-1, and temperature of 25- 55 ℃. solution ph of 7 yielded the highest tc removal efficiency (99%).

at this ph value, almost complete tc removal was achieved at a fe2o3-scallop shell nanocomposite dose of 1.6 g l-1, and 25 °c. the responsible tc removal mechanism suggested as the non-electrical π-π dispersion interaction between the bulk π system on the absorbent surface and tc molecules bearing both benzene rings and double bonds at this solution ph. tc removal efficiency appreciably enhanced up to the fe2o3-scallop dosage of 1.6 g l-1 being an optimum. adsorption rate found to be fast at lower initial tc concentrations than 40 mg l-1.

the effect of temperature on tc removal efficiency was insignificant. adsorption followed the pseudo-second order kinetic model. experimental data perfectly fitted by the langmuir equation. the maximum adsorption capacity was calculated as 49.26 mg g-1. thermodynamic analysis demonstrated that adsorption process was a spontaneous process and endothermic. the results obtained from present study proved the excellent performance of scallop shell coated fe2o3 nanoparticles as an eco-friendly adsorbent in tc treatment.