Preparation of a Porous Geopolymer (SPG) to be Used as an Adsorbent for Cu2+ Removal

Mingming Sang; Hengze Zhao; Ye Li; Lingqi Zhu

doi:10.1021/acs.langmuir.3c04013

Preparation of a Porous Geopolymer (SPG) to be Used as an Adsorbent for Cu²⁺ Removal

Langmuir. 2024 Apr 30;40(17):8851-8861. doi: 10.1021/acs.langmuir.3c04013. Epub 2024 Apr 17.

Authors

Mingming Sang^{1

2}, Hengze Zhao^{1

2}, Ye Li^{1

2}, Lingqi Zhu^{1

2}

Affiliations

¹ School of Emergency Management and Safety Engineering, North China University of Science and Technology, Tangshan, Hebei 063210, China.
² Tangshan Key Laboratory of Mine Safety and Emergency Management, Tangshan, Hebei 063210, China.

PMID: 38629768
DOI: 10.1021/acs.langmuir.3c04013

Abstract

A porous geopolymer was synthesized using steel slag (accounting for 71.6 wt %) with the aim of effectively removing Cu²⁺ ions. The chemical composition and microstructure of this material were investigated using X-ray diffraction spectroscopy, Fourier transform infrared spectroscopy, scanning electron microscope analysis, and BET method. The effects of H₂O₂ doping, H₂O doping, and the curing temperature on the properties of this porous geopolymer were systematically investigated. Subsequently, the adsorption behavior of the porous geopolymer toward Cu²⁺ was explored through static adsorption experiments. The findings reveal that there are a higher specific surface area and pore capacity for the porous geopolymer compared to the original steel slag, with a total porosity of 90.3%, compressive strength of 0.29 MPa, and volume water absorption rate of 69.4%. The adsorption capacity of this material toward Cu²⁺ is found to be 36.8 mg·g^-1, which is slightly superior to that of commercial spherical 4A molecular sieves. The adsorption process follows the quasi-first-order kinetic model, while the isothermal adsorption conforms to the Freundlich model.