Distribution of Chromium Contamination and Microbial Activity in Soil Aggregates

Distribution of chromium contamination and microbial activity in soil aggregates.

Biogeochemical transformations of redox-sensitive chemicals in soils can be strongly transport-controlled and localized. This was tested through experiments on chromium diffusion and reduction in soil aggregates that were exposed to chromate solutions. Reduction of soluble Cr(VI) to insoluble Cr(II) occurred only within the surface layer of aggregates with higher available organic carbon and hi...

Chromium diffusion and reduction in soil aggregates.

The distribution of metal contaminants such as chromium in soils can be strongly localized by transport limitations and redox gradients within soil aggregates. Measurements of Cr(VI) diffusion and reduction to Cr(III) were obtained in soil columns representing transects into soil aggregates in order to quantify influences of organic carbon (OC) and redox potentials on Cr transport distances and...

Soil Contamination by Chromium and Its Enzymatic Activity and Yielding

The effect of chromium (VI) on the activity of dehydrogenases, urease, acid and alkaline phosphatases and the yield of lupine was assayed in a pot experiment. Chromium was applied as K2Cr2O7 in the amounts of 0, 10, 20, 30, 40, 50, 100 and 150 in mg · kg of soil. The tests were conducted on brown leached soil from slightly dusty clay sand of pH in 1 M KCl 5.80. Soil was inoculated with nitragin...

Long-term tillage effects on the distribution patterns of microbial biomass and activities within soil aggregates

Size fractionation and microbial community structure of soil aggregates

The microbial community structure in various microaggregates in a loamy sand soil was investigated. The microaggregates were separated into outer and inner aggregates using a series of soil washes. Further physical fractionation of inner aggregates was achieved by separation into coarse and fine sand as macroaggregate fractions, coarse and fine silt as microaggregate fractions, and clay. Resear...