Solvent-Free Synthesis of MgO-Modified Biochars for Phosphorus Removal from Wastewater

Siyu Xu; De Li; Haixin Guo; Haodong Lu; Mo Qiu; Jirui Yang; Feng Shen

doi:10.3390/ijerph19137770

Solvent-Free Synthesis of MgO-Modified Biochars for Phosphorus Removal from Wastewater

Int J Environ Res Public Health. 2022 Jun 24;19(13):7770. doi: 10.3390/ijerph19137770.

Authors

Siyu Xu¹, De Li^{1

2}, Haixin Guo¹, Haodong Lu³, Mo Qiu¹, Jirui Yang¹, Feng Shen¹

Affiliations

¹ Agro-Environmental Protection Institute, Ministry of Agriculture and Rural Affairs, No. 31 Fukang Road, Nankai District, Tianjin 300191, China.
² College of Resources and Environment, Huazhong Agricultural University, No. 1, Shizishan Street, Hongshan District, Wuhan 430070, China.
³ Department of Chemical Engineering, University of Alberta, Edmonton, AB T6G 1H9, Canada.

Abstract

Adsorption is an efficient technology for removing phosphorus from wastewater to control eutrophication. In this work, MgO-modified biochars were synthesized by a solvent-free ball milling method and used to remove phosphorus. The MgO-modified biochars had specific surface areas 20.50-212.65 m² g^-1 and pore volume 0.024-0.567 cm³ g^-1. The as-prepared 2MgO/BC-450-0.5 had phosphorus adsorption capacities of 171.54 mg g^-1 at 25 °C and could remove 100% of phosphorus from livestock wastewater containing 39.51 mg L^-¹ phosphorus. The kinetic and isotherms studied show that the pseudo-second-order model (R² = 0.999) and Langmuir models (R² = 0.982) could describe the adoption process well. The thermodynamic analysis indicated that the adsorption of phosphorus on the MgO-modified biochars adsorbent was spontaneous and endothermic. The effect of pH, FTIR spectra and XPS spectra studies indicated that the phosphorus adsorption includes a protonation process, electrostatic attraction and precipitation process. This study provides a new strategy for biochar modification via a facile mechanochemical method.

Keywords: ball milling; biochar modification; magnesium oxide; phosphorus adsorption.

Publication types

Research Support, Non-U.S. Gov't

MeSH terms

Adsorption
Charcoal
Kinetics
Magnesium Oxide
Phosphorus
Solvents
Wastewater* / analysis
Water Pollutants, Chemical* / analysis

Substances

Solvents
Waste Water
Water Pollutants, Chemical
biochar
Charcoal
Phosphorus
Magnesium Oxide

Grants and funding

This research was sponsored by National Key Research and Development Program of China (2021YFD1700400), Central Public-interest Scientific Institution Basal Research Fund (No. Y2022QC30), Elite Youth program of the Chinese Academy of Agricultural Sciences (to Haixin Guo), Basic Frontier Project of Agro-Environmental Protection Institute, Ministry of Agriculture and Rural Affairs of China (2022-jcqyrw-ghx).