Key Laboratory of Water Pollution Treatment & Resource Reuse of Hainan Province, Key Laboratory of Tropical Medicinal Plant Chemistry of Ministry of Education, College of Chemistry and Chemical Engineering, Hainan Normal University, No. 99 Longkunnan Road, Haikou 571158 China.; Faculty of Environmental Science and Engineering, Kunming University of Science and Technology, No. 68 Wenchang Road, Kunming 650500 China
Abstract:
The reduction behavior of Fe3+ during the preparation of a zero-valent iron cocoanut biochar (ZBC8-3) by the carbothermic reduction method was analyzed. Fe3+ was first converted into Fe3O4, which was subsequently decomposed into FeO, and finally reduced to Fe0. A minor amount of γ-Fe2O3 was produced in the process. The isothermal thermodynamic data for the removal of Cu(ii) over ZBC8-3 followed a Langmuir model. The Langmuir equation revealed a maximum removal capacity of 169.49 mg g−1 at pH = 5 for ZBC8-3. The removal of Cu(ii) over ZBC8-3 fitted well to a pseudo-first-order equation, which suggested that the rate limiting step of the process was diffusion. The Cu(ii) removal mechanism on ZBC8-3 involved the reduction of Cu(ii) by Fe0 to produce Cu0 and Cu2O, while CC, C–O–, and –O–H formed a complex with Cu(ii).The Cu(ii) removal mechanism on ZBC8-3 involved the reduction of Cu(ii) by Fe0 to produce Cu0 and Cu2O, while CC, C–O–, –O–H formed a complex with Cu(ii).
