| Literature DB >> 27058131 |
Ronghua Li1, Jim J Wang2, Baoyue Zhou3, Mukesh Kumar Awasthi4, Amjad Ali5, Zengqiang Zhang5, Lewis A Gaston3, Altaf Hussain Lahori5, Amanullah Mahar6.
Abstract
Mg/Al ratio plays a significant role for anion adsorption by Mg/Al-layered double hydroxides (Mg/Al-LDHs) modified biochar. In this study, Mg/Al-LDHs biochar with different Mg/Al ratios (2, 3, 4) were prepared by co-precipitation for phosphate removal from aqueous solution. Factors on phosphate adsorption including Mg/Al ratio, pH, and the presence of other inorganic anions were investigated through batch experiments. Increasing Mg/Al ratio in the Mg/Al-LDHs biochar composites generally enhanced phosphate adsorption with Langmuir adsorption maximum calculated at 81.83mg phosphorous (P) per gram of 4:1Mg/Al-LDHs biochar at pH3.0. The adsorption process was best described by the pseudo-second-order kinetic model. Solution pH had greater effects on the phosphate adsorption by Mg/Al LDHs biochar composites with lower Mg/Al ratios. The presence of other inorganic anions decreased the phosphate adsorption efficiency in the order of F(-) > SO4(2-) > NO2(-) >Cl(-). Phosphate adsorption mechanism involves ion exchange, electrostatic attraction and surface inner-sphere complex formation. Overall, Mg/Al-LDHs biochar composites offer a potential alternative of carbon-based adsorbent for phosphate removal from aqueous solution.Entities:
Keywords: Mg/Al ratio; Phosphate; adsorption; biochar; layered double hydroxides
Year: 2016 PMID： 27058131 DOI： 10.1016/j.scitotenv.2016.03.151
Source DB: PubMed Journal: Sci Total Environ ISSN： 0048-9697 Impact factor: 7.963