Microscopic and spectroscopic characterization of humic substances from a compost amended copper contaminated soil: main features and their potential effects on Cu immobilization

1 junio, 2017 -


Medina, J.(a), Monreal, C.(b), Chabot, D.(c), Meier, S.(a)(c), González, M.E.(d), Morales, E.(a), Parillo, R.(e), Borie, F.(a), Cornejo, P.(a),


(a)Departamento de Ciencias Químicas y Recursos Naturales. Scientific and Technological Bioresources Nucleus BIOREN-UFRO, Universidad de La Frontera, Temuco, Chile
(b)Agriculture and Agri-Food Canada, Eastern Cereal and Oilseed Research Center, K.W. Neatby Building, Ottawa, K1A0C6, Canada
(c)Instituto de Investigaciones Agropecuarias (INIA), Centro de investigación Regional de Investigación Carillanca, P.O. Box 58-D, Temuco, Chile
(d)Núcleo de Investigación en Bioproductos y Materiales Avanzados (BioMA), Dirección de Investigación, Universidad Católica de Temuco, Temuco, Chile
(e)Department of Agriculture, Division of Biology and Forest Systems, University of Naples II, Via Universita, 100, Portici, NA 80055, Italy


ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH 

Volumen: 24(16) Páginas:  14104-14116

DOI: https://doi.org/10.1007/s11356-017-8981-x

Fecha de publicación:  01 de junio de 2017


Abstract

We characterized humic substances (HS) extracted from a Cu-contaminated soil without compost addition (C) or amended with a wheat straw-based compost (WSC) (H1), co-composted with Fe2O3 (H2), or co-composted with an allophane-rich soil (H3). Extracted HS were characterized under electron microscopy (SEM/TEM), energy-dispersive X-ray (X-EDS), and Fourier transform infrared (FTIR) spectroscopy. In addition, HS extracted from WSC (H4) were characterized at pH 4.0 and 8.0 with descriptive purposes. At pH 4.0, globular structures of H4 were observed, some of them aggregating within a large network. Contrariwise, at pH 8.0, long tubular and disaggregated structures prevailed. TEM microscopy suggests organo-mineral interactions at scales of 1 to 200 nm with iron oxide nanoparticles. HS extracted from soil–compost incubations showed interactions at nanoscale with minerals and crystal compounds into the organic matrix of HS. Bands associated to acidic functional groups of HS may suggest potential sorption interactions with transition metals. We conclude that metal ions and pH have an important role controlling the morphology and configuration of HS from WSC. Characterization of H4 extracted from WSC showed that physicochemical protection of HS could be present in composting systems treated with inorganic materials. Finally, the humified fractions obtained from compost-amended soils may have an important effect on metal-retention, supporting their potential use in metal-contaminated soils.


 

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