Characteristics and mechanisms of nickel adsorption on biochars produced from wheat straw pellets and rice husk

Shen, Z., Zhang, Y., McMillan, O., Jin, F. and Al-Tabbaa, A. (2017) Characteristics and mechanisms of nickel adsorption on biochars produced from wheat straw pellets and rice husk. Environmental Science and Pollution Research, 24(14), pp. 12809-12819. (doi: 10.1007/s11356-017-8847-2)

Abstract

The adsorption characteristics and mechanisms of Ni2+ on four-standard biochars produced from wheat straw pellets (WSP550, WSP700) and rice husk (RH550, RH700) at 550 and 700 °C, respectively, were investigated. The kinetic results show that the adsorption of Ni2+ on the biochars reached an equilibrium within 5 min. The increase of the solid to liquid ratio resulted in an increase of Ni2+ removal percentage but a decrease of the adsorbed amount of Ni2+ per weight unit of biochar. The Ni2+ removal percentage increased with the increasing of initial solution pH values at the range of 2–4, was relatively constant at the pH range of 4–8, and significantly increased to ≥98% at pH 9 and stayed constantly at the pH range of 9–10. The calculated maximum adsorption capacities of Ni2+ for the biochars follow the order of WSP700 > WSP550 > RH700 > RH550. Both cation exchange capacity and pH of biochar can be a good indicator of the maximum adsorption capacity for Ni2+ showing a positively linear and exponential relationship, respectively. This study also suggests that a carefully controlled standardised production procedure can make it reliable to compare the adsorption capacities between different biochars and investigate the mechanisms involved.

• Item Type: Articles
• Status: Published
• Refereed: Yes
• Glasgow Author(s) Enlighten ID: Jin, Dr Fei
• Authors: Shen, Z., Zhang, Y., McMillan, O., Jin, F., and Al-Tabbaa, A.
• College/School: College of Science and Engineering > School of Engineering > Infrastructure and Environment
• Journal Name: Environmental Science and Pollution Research
• Publisher: Springer
• ISSN: 0944-1344
• ISSN (Online): 1614-7499
• Published Online: 31 March 2017
• Copyright Holders: Copyright © 2017 The Authors
• First Published: First published in Environmental Science and Pollution Research 24(14):12809-12819
• Publisher Policy: Reproduced under a Creative Commons License