Copper, Nickel and Zinc Speciation in a Biosolid-Amended Soil: pH Adsorption Edge, μ-XRF and μ-XANES Investigations

Abstract

Metal solid phase speciation plays an important role in the control of the long-term stability of metals in biosolid-amended soils. The present work used pH-adsorption edge experiments and synchrotron-based spectroscopy techniques to understand the solid phase speciation of copper, nickel and zinc in a biosolid-amended soil. Comparison of metal adsorption edges on the biosolid-amended soil and the soil sample showed that Cu, Ni, and Zn can be retained by both soil and biosolid components such as amorphous iron phases, organic matter and clay minerals. These data are combined with microscopic results to obtain structural information about the surface complexes formed. Linear combination fitting of K-edge XANES spectra of metal hot-spots indicated consistent differences in metal speciation between metals. While organic matter plays a dominant role in Ni binding in the biosolid-amended soil, it was of lesser importance for Cu and Zn. This study suggests that even if the metals can be associated with soil components (clay minerals and organic matter), biosolid application will increase metals retention in the biosolid-amended soil by providing reactive organic matter and iron oxide fractions. Among the studied metals, the long-term mobility of Ni could be affected by organic matter degradation while Cu and Zn are strongly associated with iron oxides.

Relationship between organic matter humification and bioavailability of sludge-borne copper and cadmium during long-term sludge amendment to soil

“…Based on the results obtained in this study, the incremental change in the proportion of the Cu active fraction was positively associated with organic matter degradation, but not as closely as with HR, especially DP. In other words, a more accurate indicator can be employed to characterize the incremental change in Cu active fraction on the basis of the affirmative conclusion that uptaken Cu can be reflected by organic matter degradation (Mamindy-Pajany et al, 2014). Accordingly, the DP of sludge, which is responsible for the development of aggregate structure, also induces transformation of the Cu inactive fraction to the active fraction, to some extent, implying that the fraction of Cu is mainly regulated by sludge-borne micromolecular organic matters prior to its stabilization.…”

Equilibrium and kinetic mechanisms of woody biochar on aqueous glyphosate removal

“…Adsorption capacities were evaluated at different pHs as the pH is crucial for changes in the surface charge of adsorbents, the degree of ionization of the adsorbate as well as the speciation of the adsorbent (Mamindy-Pajany et al, 2014). Adsorption increases with the increase in pH from 11.03 mg/g to 21.6 mg/g and the maximum sorption was reached at the pH range of 5e6 and then the removal was dramatically decreased (Fig.…”

2015 Atomic Spectrometry Update – a review of advances in X-ray fluorescence spectrometry and their applications

“…The authors emphasised that XAS was a widespread and accepted research tool in the environmental and geo-sciences due to its element specicity. Solid phase speciation of Cu, Ni and Zn, which plays an important role in the long-term stability of metals in a biosolid-amended soil, was reported by Mamindy-Pajany et al 420 using m-XRF spectrometry and m-XANES. solid-liquid) as well as in different media such as plant tissues, rhizosphere, soils, sediments, ores, mineral process tailings, etc.…”