Work

Chromium removal via coprecipitation with carbonates and iron oxyhydroxides minerals: The effect of organic complexing agents

Year: 2025

Type: article

Abstract: With the recent review of the European Environmental Regulations for Water Quality, which plan to reduce contaminant concentration limits in drinking and surface waters by 2036, an increasing demand for wastewater depollution arises. Metastable amorphous nanoprecursors of iron oxyhydroxides (IOH) and calcium carbonates (CC) interact with various pollutants in natural systems via processes such as coprecipitation and adsorption. In this research, ferrihydrite (FHY) and calcium carbonates were testes for Cr (VI) retention to cover acidic to neutral environments and neutral to basic media, respectively. An original and novel approach is proposed for investigating Cr uptake capacity and mechanisms as well as minerals transformation in the presence of Cr (VI) and two biodegradable organic compounds (EDTA - ethylenediaminotetraacetic acid and EDDS - ethylenediamine-N,N'-disuccinic acid). Geochemical modelling of Cr coprecipitated species was also considered. TCLP (toxicity characteristic leaching procedure) experiments revealed that Cr remains fixed in FHY structure under near neutral conditions. One year old ferrite's stability in the presence of Cr and organic compounds was examined and showed that the addition of organics and Cr slowed FHY transformation into crystalline polymorphs. Cr (VI) sequestration by ferrites also occurred as reduced Cr (III) - its less toxic specie. Quantitatively, higher amount of Cr (VI) was removed by coprecipitation (up to 97.65 mg/g) then adsorption (ca. 33.76 mg/g). These findings provide insight into the uptake processes that influence Cr (bio)availability and mobility, that affect the elemental cycle, including transition across the trophic chain as well as at contaminated environments (i.e., mining sites and acid mine drainage) were ferrihydrite form naturally.

Source: The Science of The Total Environment

DOI: 10.1016/j.scitotenv.2025.178686

Authors: Andreea Elena Maftei, Alecsandra Lupu, Juan Diego Rodriguez-Blanco, Rémi Rateau, Loredana Brinza

Institutions: Alexandru Ioan Cuza University, Trinity College Dublin

Language: English

Topic: Chromium effects and bioremediation

Subfield: Health, Toxicology and Mutagenesis

Field: Environmental Science

Domain: Physical Sciences

SDGs: Clean water and sanitation, Responsible consumption and production

Open Access status: hybrid

Estimated APC paid: $4,250