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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 (NH 2) to improve its affinity with heavy metals. The application of PBC after NH 2 -functionalization for aqueous heavy metals removal was explored, including Pb2+, Cu2+, and different complex Cu(II) species. PBC@SiO 2 -NH 2 showed comparable performance with AC@SiO 2 -NH 2. The adsorption capacity of Pb2+ and Cu2+ by PBC@SiO 2 -NH 2 was 120 and 30 mg g−1, respectively. The NH 2 functionalization enhanced the adsorption of complex Cu(II) species, and PBC@SiO 2 -NH 2 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 ~3 times and ~6 times after NH 2 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@SiO 2 -NH 2 were investigated. The regeneration of PBC@SiO 2 -NH 2 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. [ABSTRACT FROM AUTHOR]

Abstract: Acid treatment is a routine demineralization process to obtain black carbon (BC), but there has been little systematic research about its influence on BC’s characteristics. In this study, elemental analysis, SEM, FTIR, and Boehm titration were used to investigate that effect. Our results showed that the acid treatment had little influence on the sorption of fly ash and soot to pentachlorophenol (PCP), but it greatly increased the sorption of rice chars to PCP. There were two competing effects of acid demineralization on the adsorption capacity of BC. On one hand, it increased the amount of the acidic functional groups, which decreased the adsorption capacity. On the other hand, it increased the surface and pore volume of BC and caused the emergence of hidden carbon enclosed by minerals, which in turn increased the sorptivity significantly. Especially for rice chars (600°C), after acid treatment, their surface area increased from 3.52 to 235m2 g−1 and the sorption capacity coefficient increased from 2.12 to 4.10. [Copyright &y& Elsevier]