Multifunctional magnetic MgMn-oxide composite for efficient purification of Cd2+ and paracetamol pollution: Synergetic effect and stability

A multifunctional magnetic composite (0.3Ma-MgMnLDO-a) with the function of Cd 2+ adsorption and paracetamol (PAM) degradation was successfully fabricated. Surface morphology showed that Fe 3 O 4 agglomeration was overcome on composite. The composite had high specific surface area of 105.32 m 2  g −1 and saturation magnetization of 40 emu∙g -1 . 0.3Ma-MgMnLDO-a could reach Cd 2+ adsorption equilibrium within 5 min with 99 % removal rate. The maximum adsorption capacity was 3.76 mmol·g -1 (422.62 mg g -1 ), which apparently higher than that of Fe 3 O 4 -a and MgMnLDO-a, indicating that the Fe/Mn synergism results in excellent ability for Cd 2+ adsorption. Moreover, the composite could efficiently activate peroxymonosulfate (PMS) to rapid degrade PAM with the highest first-order rate constants (k obs  = 0.116 min -1 ) and total organic carbon (TOC) removal rate (67.7 %), which also due to the contribution of Fe/Mn synergism in PMS activation. The cycling of Mn III /Mn IV and Fe II /Fe III played an important role in activating PMS to generate O 2 − • , 1 O 2 and OH for degradation. The composite exhibited both stable adsorption and catalytic performance on wide pH (3–9) and five reuse cycles. Notably, there was mutual promotion between Cd 2+ and PAM adsorption, while the coexistence of Cd 2+ had slight inhibition on PAM degradation. Overall, the magnetic composite had promising application for purifying heavy metals and pharmaceuticals.