To solve the problem of limited adsorption efficiency of pristine biochar for phosphate, a novel biochar composite was prepared from different feedstocks and coal gangue by one facile-step pyrolysis method. The effects of pyrolysis temperature, adsorbent dosage, pH of the solution, and coexisting ions on phosphate adsorption were analyzed. The adsorption performance and mechanism of phosphate in water were investigated. The application of the phosphorus-laden (P-laden) composite as slow-release fertilizer was evaluated by a germination test. The results showed that the maximum phosphate adsorption capacity of coal gangue modified oilseed rape straw biochar prepared at 700 degrees C (CG-OR700) was 7.9 mg/g at pH 4.0, which is 4.6 times that of pristine biochar. The adsorption process can be well fitted by the pseudo-second-order kinetic and Langmuir isotherm adsorption model. The mechanism of phosphate adsorption mainly includes surface precipitation, ligand exchange, and electrostatic attraction. The P-laden biochar can be used as a slow-release fertilizer to promote seed germination and growth. This study shows that the coal gangue modified biochar composite can not only be used to remove phosphate from wastewater, but also be used as a slow-release fertilizer, providing a new way for the phosphorus recovery and resource utilization of solid wastes. (C) 2020 Elsevier B.V. All rights reserved.
| SCIENCE OF THE TOTAL ENVIRONMENT Volume: 758 Article Number: 143664 DOI: 10.1016/j.scitotenv.2020.143664 Published: MAR 1 2021 |
| Wang, Bing; Ma, Yuena; Lee, Xinqing; Wu, Pan; Liu, Fang; Zhang, Xueyang; Li, Ling; Chen, Miao |
-Guizhou Univ, Coll Resource & Environm Engn, Guiyang 550025, Guizhou, Peoples R China
-Minist Nat Resources, Key Lab Karst Environm & Geohazard, Guiyang 550025, Guizhou, Peoples R China
-Minist Educ, Guizhou Karst Environm Ecosyst Observat & Res Stn, Guiyang 550025, Guizhou, Peoples R China
|Author(s) from IGCAS || MA, Yuena; LEE, Xinqing |
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