• Microbiology and Biotechnology Letters
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• v.44 no.4
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• pp.550-556
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• 2016

Groundwater heat pump (GWHP) systems must consider phenomena such as clogging to improve system efficiency and maintenance. In this study, we evaluated the prokaryotic diversity in a boring slime sample obtained at a depth of 10 m, which represented an undisturbed sample not affected by aquifer drawdown. Bacteria belonging to the phyla Proteobacteria (20.8%), Acidobacteria (18.8%), Chloroflexi (16.9%), and Firmicutes (10.2%) were found. Additionally, 144 species were identified as belonging to the genus Koribacter. Archaeal phyla were detected including Thaumarchaeota (42.8%), Crenarchaeota (36.9%), and Euryarchaeota (17.4%) and the class level comprised the miscellaneous Crenarchaeota group (MCG), Finnish forest soil type B (FFSB), and Thermoplasmata, which collectively accounted for approximately 69.4% of the detected Archaea. Operational taxonomic units (OTUs) were analyzed to reveal 3,565 bacterial and 836 archaeal OTUs, with abundances of 7.81 and 6.68, and richnesses of 5.96E-4 and 2.86E-3, respectively. The distribution of the groundwater microbial community in the study area showed a higher proportion of non-classified or unidentified groups compared to typical communities in surface water and air. In addition, 135 (approx. 1.9%) reads were assigned to a bacterial candidate associated with clogging.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.28 no.5C
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• pp.293-301
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• 2008

Soil profiling is one of the most important work among geotehnical engineering practice. Generally, soil profile is estimated from the observation of soil samples during subsurface exploration but such estimation also includes some experiencing aspects such as flushed water from the borehole, slime colour, boring speed and so on. In addition, since the capacity of hydraulic drill rig is significantly increased, thin layers might be easily missed. So, continuous soil profile is almost impossible over all depth to be bored from conventional subsurface exploration. While CPT or CPTu can serve continuous soil profile information over all depth generally in 5cm interval. Many charts or methods for soil profile from CPT result have been proposed during last several decades over the world. However they have not been verified in local ground condition in Korea. In this research, CPT results and soil classification results based on USCS were compiled from 17 sites over the Korea. Soil classification results by using 7 CPT soil classification charts were compared with those of USCS for the compiled database. Most proper CPT soil classification chart for Korean soil characteristics was evaluated and effective parameters for the soil classification from CPT were discussed. Finally interrelationship between CPT soil classification chart and USCS soil classification was evaluated.