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Changes in microstructure of soils following extraction of organically bonded metals and organic matter
Author(s) -
WIERZCHOS J.,
CIRIA C. ASCASO,
GARCIAGONZALEZ M. T.
Publication year - 1992
Publication title -
journal of soil science
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.244
H-Index - 111
eISSN - 1365-2389
pISSN - 0022-4588
DOI - 10.1111/j.1365-2389.1992.tb00156.x
Subject(s) - microstructure , organic matter , soil water , chemistry , adsorption , materials science , mineralogy , metallurgy , organic chemistry , geology , soil science
SUMMARY The influence of selective removal of organically bonded metals and organic matter on soil microstructure was investigated. Two samples of soils with different mineralogical, chemical and mechanical composition were treated with acetylacetone in both polar and non‐polar solvents to dissolve amorphous organic iron and aluminium, and with hydrogen peroxide to destroy organic matter. Transmission electron micrographs of ultrathin sections and scanning electron micrographs of <5−μm fractions of the extracted soils showed distinct changes of microstructure of clays after successive removal of cementing agents. Although untreated soils showed flocculent or honeycomb structure, soils with organic matter and organically bonded metals removed showed turbostratic domain structure with stepped clusters. The changes in microstructure of soils following extraction were confirmed by determination of pore‐size distribution and total cumulative volume of pores using the mercury porosimetry method. In addition, the surface area of the extracted soils was determined by water adsorption. The results showed that organically bonded iron and aluminium and organic matter distinctly influence the fabric of microstructure as flocculating agents.