Sammanfattning

The geochemistry of copper (Cu) is generally assumed to be controlled by organic matter in soils. However, the role of clay and iron oxide minerals may be understated. Soil density fractionation, X-ray diffraction (XRD), and X-ray absorption spectroscopy (XAS) were combined to assess the long-term behavior of Cu in an agricultural soil subject to organic waste application. Two unprecedented molecular environments of natural Cu (i.e. Cu inherited from the parent rock) in soils are reported: Cu dimer in the interlayer of vermiculite and Cu structurally incorporated within hematite. Moreover, the soil naturally containing Cu-vermiculite, Cu-hematite, but also Cu-kaolinite (Cu-total = 122 mg.kg(-1)) was amended over 11 years with Cu-rich pig slurry in which Cu was 100 % Cu(I) sulfide. Natural Cu associated with clay and iron oxide minerals persisted in the amended soil, but the exogenous Cu(I) sulfide was unstable. The increase in Cu concentration in the amended soil to 174 mg.kg(-1) was accounted for the increase of Cu sorbed to kaolinite and Cu bound to organic matter. These results are important for better understanding the natural occurrence of Cu in soils and for assessing the environmental impacts of organic waste recycling in agricultural fields.

Nyckelord

XAS; Cu dimer; Cu-vermiculite; Cu-hematite; Cu-kaolinite; Pig slurry; Agricultural recycling

Publicerad i

Science of the Total Environment
2022, Volym: 848, artikelnummer: 157779
Utgivare: ELSEVIER

SLU författare

• Formentini, Thiago

  • Institutionen för mark och miljö, Sveriges lantbruksuniversitet
    
  • Universidade Federal Parana

UKÄ forskningsämne

Markvetenskap
Miljö- och naturvårdsvetenskap


Publikationens identifierare

DOI: https://doi.org/10.1016/j.scitotenv.2022.157779

Permanent länk till denna sida (URI)

https://res.slu.se/id/publ/119559