UBC Theses and Dissertations
Distribution and characterization of organo-clay complexes in selected Lower Fraser Valley soils Parasher, Chander Dutt
In the study of the distribution of organo-clay complexes, thirty-four samples representing eight soil types were collected from the Lower Fraser Valley and the effectiveness of the three methods, viz. simple dispersion, insonation and chelating resin were examined. The use of a chelating resin was found most effective for quantitative studies while insonation was preferred for qualitative studies. For detailed characterization of the organo-clay complexes eight samples were chosen and ultrasonic agitation was used for isolating the organo-clay complexes. The organo-clay complexes varied widely in characteristics. The yield of complexes by simple dispersion, ultrasonic vibration and chelating resin ranged from 0.15 to 10.42, 0.20 to 17.20 and 1.25 to 25.70 percent by weight, respectively. The organo-clay complexes were analysed for their content of carbon, nitrogen, iron, silicon, aluminum along with carbohydrates, humic (HA) and fulvic (FA) acids. The C/N ratio of the selected complexes varied between 5.5 and 17.0 and carbohydrate content accounted for 3.3 to 16.0 percent of the complex carbon. The HA: FA ratio indicated that the major proportion of the organic component in this association was of fulvic nature, except in the case of the Podzolic Bf horizon samples in which about 2/3 of the extractable material was in the humic fraction. X-ray diffraction, infrared (IR) and differential thermal analysis were also conducted. The mineralogy was not observed to differ to a great extent except in the Ae horizon sample of the Orthic Podzol and the Btg of the Orthic Gleysol where montmorillonite was present in significant amounts. In most of the samples examined interlamellar inclusion of the organic matter was also observed. The differential thermal analysis exhibited a band near 320°C probably due to the elimination of some form of organic fraction. The IR studies indicated the bonding of silicon to organic components through oxygen linkages, however, there was no conclusive evidence of amide linkage formation between organic components and clay minerals.
Item Citations and Data