Affiliations 

  • 1 Faculty of Environment, Van Lang University, Ho Chi Minh City 70000, Vietnam
  • 2 Nanotechnology and Catalysis Research Centre, Universiti Malaya, Kuala Lumpur 50603, Malaysia
  • 3 School of Chemical Sciences, Universiti Sains Malaysia, Penang 11800, Malaysia
ACS Omega, 2023 Nov 07;8(44):41258-41272.
PMID: 37970056 DOI: 10.1021/acsomega.3c04691

Abstract

In this study, geopolymer originating from locally industrial byproducts as red mud (RM) was successfully prepared in the presence of different loadings of rice husk ash (RHA) used for the adsorption of methylene blue (MB) in wastewater. During geopolymerization, various mixing amounts between RM and RHA were conducted when the weight ratio of binder solution/activated alkali-metal solution (Na2SiO3/ NaOH 7 M) was 2.5 and the curing temperature was set at 60 °C for 24 h. As a result, the surface area value of the prepared geopolymer composited with RHA at 0 and 60% was increased from 19.2 to 29.5 m2/g, while the BJH pore size of the prepared geopolymer was reduced to 6.68 and 5.76 nm, respectively. In the dye removal test, higher additions of RHA in the RM-geopolymer maintained better retention of the MB ion due to the increase in the adsorption binding site. The maximum uptake amount of dyes performed at pH 8 was changed from 6.59 to 10.74 mg/g, while RHA was from 0 to 60% after 180 min of immersion in MB solution. The adsorption isotherms well obeyed the Langmuir model, as the relative coefficient R2 was 0.999. Based on these, the initial agricultural waste as RHA and industrial byproducts as RM were valued as functional materials used for dye treatment in wastewater.

* Title and MeSH Headings from MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.