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Sorption behavior of non-polar hydrophobic organic chemicals on soils, sediments of Bangladesh
Published in Poul L. Bjerg, Peter Engesgaard, Thomas D. Krom, Groundwater 2000, 2020
Md. Mokhlesur. Rahman, Sybille Kleineidam, Peter Grathwohl
Sorption isotherms were determined using different organic compounds (1,2DCB, Heptachlor, TCE and phenanthrene). The results are summarized using the phenanthrene data (Fig. 1 left). The residuum and floodplain soil samples revealed distribution coefficients close to values calculated by the Karickhoff correlation (Karickhoff et al. 1979). The peat and deltaic samples showed slightly higher Koc-values. In general the underlying aquifer samples follow the trend of the soils (e.g. deltaic aquifer sediment also shows higher Koc-values). Since the soil samples were collected on horizon basis a closer look was taken to the deltaic sediments. Organic carbon normalized distribution coefficients and the non-linearity of the sorption isotherms increased with sampling depth. This indicates an influence of weathering or diagenesis on the sorption behavior which is in coincidence to findings from others (Njoroge et al. 1998).
Mineral exploration
Published in Odwyn Jones, Mehrooz Aspandiar, Allison Dugdale, Neal Leggo, Ian Glacken, Bryan Smith, The Business of Mining, 2019
Odwyn Jones, Mehrooz Aspandiar, Allison Dugdale, Neal Leggo, Ian Glacken, Bryan Smith
Sampling of lateritic residuum is done by chip sampling when outcrop-ping at the surface or with an auger for areas with soil cover or via drilling for deeper zones such as when they occur buried. Sampling the ferruginous gravel materials should be done without bias to type of fabric, such as nodule or pisoliths, and a minimum of a 1 kg sample should be taken, preferably over a 10 m radius. The depth of sampling can be dictated by the scale of the survey. For example, in reconnaissance lateritic surveys, the surface samples can be taken at a 1–3 km spacing collecting near surface ferruginous materials (Figure 2.16), whereas prospect scale surveys should preferentially sample lower ferruginous horizons of the duricrust at closer sample spacing (400 m) (Butt et al., 2000).
The Biodegradative Controlled Release of Pesticides from Polymeric Substrates
Published in Agis F. Kydonieus, Controlled Release Technologies: Methods, Theory, and Applications, 2019
G. G. Allan, J. W. Beer, M. J. Cousin, R. A. Mikels
However, preliminary efficacy data can certainly be obtained by this means. Therefore, before field testing, three distinct 2,4-DB controlled release combinations with Douglas-fir bark were examined for their selective toxicity to deciduous brush in the presence of conifers.83 The test plants selected were 2- to 3-year-old Douglas-fir and western red alder seedlings supplied by the Department of Natural Resources of the State of Washington. Each plant was individually transplanted outside in Seattle, Washington on December 6, 1969 into pots containing a weed-free soil having a surface area of 140 cm2. The soil was an acidic (pH 6) Alderwood, sandy loam comprising organic matter (15.2%) and a residuum of clay (15.1%), silt (22.7%) and sand (62.2%).
Geomorphic provinces and regolith-landform evolution of the Capricorn Orogen, Western Australia
Published in Australian Journal of Earth Sciences, 2021
R. L. Thorne, S. C. Spinks, R. R. Anand
Lateritic residuum comprises ferruginous units that are formed by weathering, mineral precipitation and residual accumulation in the weathering profile. Lateritic residuum can be further defined as ferruginous gravels and duricrusts. Lateritic residuum is mostly observed in the Deeply Weathered Province in Transect 10. The lateritic residuum is found in situ overlying mottled and ferruginous saprolites and commonly found beneath variably hardpanised transported colluvium and alluvium. The position of the residuum in the landscape, below transported material, suggests it represents some of the oldest evidence for ferruginisation in the region.