The contribution of free iron oxides to positive and negative charge distribution has been studied on soils and synthetic kaolinite-iron oxide complexes over a wide range ofpH values. The charge on the iron oxides is pH-dependent, being positive at low and negative at high pH values, respectively, and accounts for a considerable proportion of the pHdependent negative charge in soils. Iron oxide...

Removal of dissolved organic carbon (DOC) from water resulting from adsorption and microbial uptake was examined to determine the importance of biotic and abiotic pathways. Physical-chemical adsorption to components of the stream sediment or water and biotic assimilation associated with the microbial population was determined in recirculating chambers utilizing leachate from alder (Alnus rubru)...

Chimpanzees of the Sonso community, Budongo Forest, Uganda were observed eating clay and drinking clay-water from waterholes. We show that clay, clay-rich water, and clay obtained with leaf sponges, provide a range of minerals in different concentrations. The presence of aluminium in the clay consumed indicates that it takes the form of kaolinite. We discuss the contribution of clay geophagy to...

The mineralogy and chemistry of the less than 20μm fraction of marine sediments at Morphou Bay, north-west Cyprus, are presented to characterise fine-grained sediment supplies from basic and ultrabasic rocks of the Troodos Massif within a typological setting. The sediments comprise a mixture of smectite, illite, kaolinite and iron rich chlorite. They also contain amorphous iron oxides/hydroxide...

Groundwater flow in sedimentary rock saprolite, and in soils derived from this material, is strongly influenced by sedimentary layering and fractures inherited from the parent bedrock. The main objectives of this study were to determine whether parent bedrock lithology and infilling of fractures and other macropores with pedogenically derived clays and Fe/Mn oxides also play major roles in cont...

Despite the ecosystem functioning they provide, termite pedoturbation along toposequence is overlooked in genesis of semiarid soils. Therefore, we aimed to describe morphological and physicochemical properties that lead classification termite-mediated In this study, representative pedons, one on each slope class, were described classified for five different topographical positions, soil genetic...

The negative impact of nitrate (NO3) on groundwater supplies has sparked a great deal of interest and concern in recent years, particularly in areas where coarse-textured soils abound. In light of this concern, the anion exchange chemistry of eight soils from the Middle Atlantic region was studied with particular emphasis on NO3 retention and kinetics. The soils were chosen to encompass a range...

19 Phosphorus (P) losses from agricultural soils constitute a main driver for eutrophication of the 20 Baltic Sea. There is limited knowledge about sorption and release processes of P in these soils, 21 especially concerning the effects of fertilization. In this study, P speciation of the clay fractions 22 from six different soils in long-term fertility experiments in Sweden was investigated by...