Effects of excessive impregnation, magnesium content, and pyrolysis temperature on MgO-coated watermelon rind biochar and its lead removal capacity

Zhang, J., Hou, D., Shen, Z., Jin, F. , O'Connor, D., Pan, S., Ok, Y. S., Tsang, D. C.W., Bolan, N. S. and Alessi, D. S. (2020) Effects of excessive impregnation, magnesium content, and pyrolysis temperature on MgO-coated watermelon rind biochar and its lead removal capacity. Environmental Research, 183, 109152. (doi: 10.1016/j.envres.2020.109152) (PMID:32006766)

Abstract

MgO-coated watermelon rind biochar (MWRB) is a potentially highly-effective waste-derived material in environmental applications. This research aims to provide valuable insights into the optimization of the production of MWRB for superior environmental performance. It was found that the Mg content of the MWRB could be easily controlled by adjusting the Mg/feedstock mass ratio during excessive impregnation. The BET surface area was found to first increase and then decrease as the Mg content of the MWRB (produced at 600 °C) increased from 1.52% to 10.1%, with an optimal surface area of 293 m2/g observed at 2.51%. Similarly, an optimum pyrolysis temperature of 600 °C was observed in the range of 400–800 °C for a maximum surface area of the MWRB at a fixed Mg/feedstock ratio of 0.48% (resulting in MWRBs with Mg contents of 1.89–2.51%). The Pb removal capacity of the MWRB (produced at 600 °C) increased with increasing Mg content, with a greatest Pb removal capacity of 558 mg/g found for the MWRB with the highest Mg content (10.1%), an improvement of 208% over the 181 mg/g Pb removal capacity of unmodified WRB produced at 600 °C. The Pb removal capacity of the MWRB (produced with 1.89–2.51% Mg) was also discovered to increase from 81.7 mg/g (at 400 °C) to 742 mg/g (at 700 °C), before dropping to 368 mg/g at 800 °C. These findings suggest that the MWRB can be more efficiently utilized in soil and water remediation by optimizing its synthesis conditions.

• Item Type: Articles
• Additional Information: This work was supported by China's National Water Pollution Control and Treatment Science and Technology Major Project (Grant No. 2018ZX07109-003), and the National Key Research and Development Program of China (Grant No. 2018YFC1801300). The third author would like to thank the Killam Trusts of Canada for kindly providing the Izaak Walton Killam Memorial Postdoctoral Fellowship.
• Status: Published
• Refereed: Yes
• Glasgow Author(s) Enlighten ID: Jin, Dr Fei
• Authors: Zhang, J., Hou, D., Shen, Z., Jin, F., O'Connor, D., Pan, S., Ok, Y. S., Tsang, D. C.W., Bolan, N. S., and Alessi, D. S.
• College/School: College of Science and Engineering > School of Engineering > Infrastructure and Environment
• Journal Name: Environmental Research
• Publisher: Elsevier
• ISSN: 0013-9351
• ISSN (Online): 1096-0953
• Published Online: 20 January 2020
• Copyright Holders: Copyright © 2020 Elsevier
• First Published: First published in Environmental Research 183:109152
• Publisher Policy: Reproduced in accordance with the copyright policy of the publisher