Journal of Colloid and Interface Science, Vol.559, 215-225, 2020
Adsorption behavior and mechanism of Pb(II) and complex Cu(II) species by biowaste-derived char with amino functionalization
This work aimed to develop a feasible technology to reuse dead pig biowaste for heavy metals removal, which was first carbonized into pig bone char (PBC) after pyrolysis and further functionalized with amino (-NH2) to improve its affinity with heavy metals. The application of PBC after NH2-functionalization for aqueous heavy metals removal was explored, including Pb2+, Cu2+, and different complex Cu(II) species. PBC@SiO2-NH2 showed comparable performance with AC@SiO2-NH2. The adsorption capacity of Pb2+ and Cu2+ by PBC@SiO2-NH2 was 120 and 30 mg g(-1), respectively. The NH2 functionalization enhanced the adsorption of complex Cu(II) species, and PBC@SiO2-NH2 exhibited good performance under a wide pH range and coexisting ions. The adsorption of Cu(II)(EDTA) species with an EDTA/Cu(II) molar ratio of 1.0 by PBC would be enhanced similar to 3 times and similar to 6 times after NH2 functionalization and further addition of Fe3+, respectively. The results of EDX, elemental mapping, and XPS confirmed the adsorption of Cu(II) species. The adsorption kinetics, isotherm, and thermodynamics of different Cu(II) species by PBC@SiO2-NH2 were investigated. The regeneration of PBC@SiO2-NH2 was easily performed via acidic wash. These results suggested the application potential of the reuse of biowaste, which could be a promising adsorbent for aqueous heavy metals after specific functionalization. (C) 2019 Elsevier Inc. All rights reserved.