Adsorption of phosphorus by calcium-flour biochar: Isotherm, kinetic and transformation studies. (March 2018)

• Record Type: Journal Article
• Authors: Wang, Shengdan; Kong, Lingjun; Long, Jianyou; Su, Minhua; Diao, Zenghui; Chang, Xiangyang; Chen, Diyun; Song, Gang; Shih, Kaimin
• Is Part Of: Chemosphere. Volume 195(2018)
• Page Start: 666
• Page End: 672
• Publication Date: 2018-03
• Subjects: Phosphorus -- HydroxyLapatite -- Calcium hydroxide -- Ca-BC -- Adsorption; Pollution -- Periodicals; Pollution -- Physiological effect -- Periodicals; Environmental sciences -- Periodicals; Atmospheric chemistry -- Periodicals; 551.511
• DOI: 10.1016/j.chemosphere.2017.12.101
• Languages: English
• ISSNs: 0045-6535

Abstract

Abstract: Discharging phosphorus (P)-contaminated water directly into the aquatic environment leads to resource loss and eutrophication. Thus, removing P from waste streams is imperative. In this study, calcium-decorated biochar (Ca-BC) in different mass ratios of Ca to BC was designed to effectively adsorb P from solution. Ca-BC was characterized through X-ray diffraction (XRD) analysis, followed by isotherm and kinetic adsorption experiments. The decorated Ca on the BC surface was found to have preferred P adsorption ability. A design of calcium hydroxide (Ca(OH)2 ) to flour in a mass ratio of 2:1 was found to have a maximum adsorption capacity of 314.22 mg g −1 for P. The Langmuir and pseudo-second-order models fit the sorption process adequately. XRD analysis indicated that the preferable adsorption ability to P was due to the reaction of Ca(OH)2 and PO4 3−, forming the hydroxylapatite (Ca5 (PO4 )3 (OH)) crystal. The P in solution was transformed to the crystal. Thus, Ca-BC is an environmental friendly and low-cost sorbent for P removal. Highlights: Ca-decorated biochar was synthesized. Excellent sorption capacity of 314.22 mg g −1 for P was observed. Langmuir and pseudo-second-order models fit the sorption process adequately. Formation of Ca5 (PO4 )3 (OH) crystal contributes to P sorption.