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Highly efficient removal of cadmium from aqueous solution by ammonium polyphosphate-modified biochar
journal contribution
posted on 2023-05-21, 16:10 authored by Huang, K, Hu, C, Tan, Q, Yu, M, Sergey ShabalaSergey Shabala, Yang, L, Sun, XPhosphorus-modified biochars are considered as good materials for the removal of heavy metals from wastewater. However, the efficacy of ammonium polyphosphate-modified biochar in cadmium (Cd(II)) adsorption remains largely unknown. In this work, the biochar was respectively modified with ammonium polyphosphate (PABC), phosphoric acid (PHBC) and ammonium dihydrogen phosphate (PNBC) to enhance its adsorption performance for heavy metals from wastewater. The properties of biochar before and after modification and P speciation on the surface of the modified biochar were investigated with FTIR, SEM-EDS, XPS, XRD and 31P NMR, and the adsorption capacity was evaluated by batch adsorption experiments. The results demonstrated that the optimal adsorption performance could be achieved at the solution pH = 4, and the pseudo-second-order and Langmuir models could well describe the Cd(II) adsorption process. The maximum adsorption capacity of PABC, PHBC and PNBC for Cd(II) was 155, 138 and 99 mg g−1, which were 4.84, 4.32 and 3.10 folds that of original biochar, respectively. The 31P NMR showed that orthophosphate accounted for 82.1%, 62.8% and 54.5% of P in PABC, PHBC and PNBC, respectively, which decreased to 28.24%, 33.51% and 29.34% after Cd(II) adsorption, indicating that the orthophosphate ratio in P-modified biochar surface could significantly affect Cd adsorption by forming phosphate precipitate. This work implies that the PABC has greater potential in the removal of Cd from wastewater relative to PHBC and PNBC.
History
Publication title
Chemosphere: Chemistry, Biology and Toxicology As Related to Environmental ProblemsVolume
305Article number
135471Number
135471Pagination
1-8ISSN
0045-6535Department/School
Tasmanian Institute of Agriculture (TIA)Publisher
Pergamon-Elsevier Science LtdPlace of publication
The Boulevard, Langford Lane, Kidlington, Oxford, England, Ox5 1GbRights statement
© 2022 Published by Elsevier Ltd.Repository Status
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