As(III) removal from aqueous solution by katoite (Ca3Al2(OH)12)

Chemosphere. 2020 Dec:260:127555. doi: 10.1016/j.chemosphere.2020.127555. Epub 2020 Jul 9.

Abstract

As (III) is widely distributed in groundwater which is relatively harder to be removed comparing to As (V). Co-grinding Ca(OH)2 with Al(OH)3 was conducted to manufacture katoite (Ca3Al2(OH)12) for the complete removal of As(III) (concentration below drinking water standard of WHO (<10 ppb)) during one-step agitation operation. X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR), thermogravimetric analysis (TG), and X-ray photoelectron spectroscopy (XPS) were applied for the illustration of adsorption mechanism. Katoite could intercalate As(III) into the layered space forming arsenite pillared Ca-Al layered double hydroxide (LDH). The coexisting anions such as Cl-, SO42-, and NO3- had minor effects on As (III) removal performance using katoite. Techno-economic analysis demonstrated the feasibility of large-scale katoite production and its practical application for As(III) polluted groundwater purification, especially in the undeveloped areas where groundwater was used as irrigation and drinking water.

Keywords: Arsenite; Ball milling; Intercalation; Katoite.

MeSH terms

  • Adsorption
  • Arsenites / chemistry*
  • Groundwater / chemistry
  • Hydrogen-Ion Concentration
  • Hydroxides / chemistry
  • Photoelectron Spectroscopy
  • Spectroscopy, Fourier Transform Infrared
  • Water / analysis
  • Water Pollutants, Chemical / analysis
  • Water Pollutants, Chemical / chemistry*
  • Water Purification / methods*
  • X-Ray Diffraction

Substances

  • Arsenites
  • Hydroxides
  • Water Pollutants, Chemical
  • Water
  • hydroxide ion
  • arsenite