Simplified removal of Fe(II) and Mn(II) from groundwater via oxidative coprecipitation with portlandite and subsequent neutralization with CO2 bubbling
Year: 2026
Type: article
Abstract: Groundwater enriched with Fe(II) and Mn(II) at concentrations exceeding 0.3 mg/L and 0.1 mg/L, respectively, may pose serious health risks upon consumption and therefore requires treatment. This study developed a simple, rapid, and effective method to remove Fe(II) and Mn(II) from groundwater (with removal efficiencies greater than 99%) by accelerating their precipitation and oxidation (particularly for iron) under alkaline conditions (at pH of approximately 12.2), constrained with calcium hydroxide (Ca(OH) 2 ). Alkaline water is then neutralized by CO 2 bubbling for 3–5 min. This method requires short treatment time (shorter than 1 h), a low Ca(OH) 2 dosage (0.5–3.0 g/L), and ambient temperature, and can be easily scaled up to treat large volumes of water because only existing conventional technology is needed (e.g., tanks with agitators at atmospheric pressure, pumps, and injectors). In addition, the advantage of this method is that other metallic pollutants can also be removed during the treatment, and the resulting red solid residue, mainly composed of calcite and iron oxyhydroxide (the FeOOH type) nanoparticles, can be reused as pigments, sorbents, or mineral filler powders for industrial applications. This integrated method can be successfully used to remove toxic dissolved ions from water while generating solid residues with industrial uses.
Source: Water Science and Engineering
Language: English
Subfield: Water Science and Technology
Field: Environmental Science
Domain: Physical Sciences
Open Access status: diamond
OpenAlex ID: W7171744053