New Method to Determine the True Water Content of Organic Soils

Suits, L David; Sheahan, TC; O'Kelly, BC

doi:10.1520/gtj11963

Cited by 15 publications

(8 citation statements)

References 4 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Comprehensive descriptions of the geotechnical and hydraulic properties of these materials have been reported for the sewage sludge by O'Kelly (2004bO'Kelly ( , 2005aO'Kelly ( , 2006O'Kelly ( , 2008aO'Kelly ( , 2013b) and the WTR material by O'Kelly (2008bO'Kelly ( , 2014 and Quille (2009, 2010). The oven-drying characteristics of the fraction of the sewage sludge material passing the 425-μm sieve, which had an LOI of 70%, have been reported previously by O'Kelly (2004aO'Kelly ( , 2005bO'Kelly ( , 2005c, employing the same convection oven as that used in the present investigation. The oven-drying characteristics of the coarse fibrous fraction (~10% of the material's total dry mass) retained after wet sieving the bulk material on the 425-μm sieve are investigated in the present study.…”

Section: Test Materialssupporting

confidence: 68%

“…For instance, the ASTM standard test method for water content determinations on soil and rock (ASTM D2216; ASTM, 2010) states that, for fibrous peat and other highly organic soils, it may be desirable to use a lower ovendrying temperature of 60°C or, alternatively, use desiccators at ambient laboratory temperature. However, since the specimen dry mass is a function of oven temperature, water contents determined in these studies will be lower than values determined for the drying temperature range 100-110°C on account of reduced potential for charring and oxidation of susceptible organic matter, but also because significant amounts of residual pore water can remain within the test specimen (O'Kelly, 2004a(O'Kelly, , 2005b(O'Kelly, , 2005c(O'Kelly, , 2005d. Hence, what is potentially lost by this inconsistency in oven temperature values adopted is the ability to meaningfully compare reported values of water content, especially for sensitive materials.…”

Section: Oven-drying Temperaturementioning

confidence: 84%

“…This would result in the measurement of apparently higher values of water content (O'Kelly, 2005b(O'Kelly, , 2005d. By contrast, at too low a temperature, not all of the pore water would be driven off (O'Kelly, 2004a(O'Kelly, , 2005c.…”

Section: Introductionmentioning

confidence: 98%

“…presents values of α105°C plotted against drying temperature for the two fractions of the sewage sludge (i.e., passing and retained on the 425-mm sieve), with the former determined from data reported by O'Kelly (2004aO'Kelly ( , 2005bO'Kelly ( , 2005c. Gilbert (1990), Skempton and Petley (1970) and O'Kelly (2005b), which included peats, clay, silt, sludge and mud having LOI values of 5•5-99%, were all relatively insensitive to oven temperature (α105°C ≥ 0•97 for 80°C and 85°C).…”

mentioning

confidence: 99%

See 3 more Smart Citations

Drying temperature and water content–strength correlations

O’Kelly¹

2014

Environmental Geotechnics

View full text Add to dashboard Cite

For water content determinations on organic soils, several researchers have adopted lower oven-drying temperatures in the range 35−90°C (instead of the standardised range for mineral soils of 100-110°C) in order to prevent possible charring, oxidation and (or) vaporisation of substances other than water. However, at too low a temperature, not all of the relevant water is driven off. One major consequence of using such a wide range of drying temperatures for more sensitive materials is to produce considerable disparity in interpolated index values and in deduced correlations between water content and other engineering properties. This paper discusses the pros and cons regarding the ovendrying temperature adopted for routine water content determinations on organic sludges and residues. It concludes by recommending a standardised oven temperature of 105-110°C or 105 ± 5°C, a 24-h drying period and a suggested minimum wet specimen mass of 50 g.

show abstract

Section: Test Materialssupporting

confidence: 68%

Section: Oven-drying Temperaturementioning

confidence: 84%

Section: Introductionmentioning

confidence: 98%

mentioning

confidence: 99%

See 2 more Smart Citations

Drying temperature and water content–strength correlations

O’Kelly¹

2014

Environmental Geotechnics

View full text Add to dashboard Cite

show abstract

“…an apparent lower water content value may be deduced instead). For instance, O'Kelly (2005c) showed that the mass of residual pore water in a test specimen of sewage sludge material oven dried at 60°C was greater than the mass loss due to any charring, oxidation and/or vaporisation of susceptible organic matter at 105°C. Further, some WTR materials can have unusual oven-drying behaviour -for example, the mass of alum WTR test specimens investigated by O'Kelly (2014b) showed no signs of equilibrating after a 34-d drying period at 105°C.…”

Section: Water Content Determinationsmentioning

confidence: 99%

Geotechnics of municipal sludges and residues for landfilling

O’Kelly

2016

Geotechnical Research

View full text Add to dashboard Cite

This paper presents a comprehensive review of reported field and laboratory investigations and theoretical work concerning the geotechnical behaviour/properties of water treatment residue (WTR), biosolids and sewage sludge materials, which are by-products of municipal water and wastewater treatment processes. After describing the backgrounds to the generation of these materials and various disposal options (with a focus on landfilling), including associated geotechnical issues, their physical, geotechnical index, compaction, undrained strength and effective-stress strength properties are described, including the effects of oxidation, biodegradation and viscous gellike pore fluid for biosolids/sewage sludge material. Characteristic compressibility, consolidation and permeability behaviour/properties are also presented for these materials and linked with microstructure and the chemicals added during the treatment processes. The paper then focuses on various geotechnical issues pertinent to landfill (monofill) disposal of these materials, including undrained strength requirements, design strength, on-site and laboratory strength measurements and water content-strength correlations. Since such correlations are material specific, with the geotechnical properties of biosolids, sewage sludge and WTR materials varying between water/wastewater treatment plants, they cannot be applied more widely with confidence. Alternative approaches to predicting undrained strength are described, including a power-law strength relationship with water content, which can be applied more generally. , 2008a). The type and amount of chemicals added depends on the nature of the source water, but primarily on its turbidity and hardness. The coagulants cause the colloidal particles present to aggregate into flocs (with the polyelectrolyte also acting as a binding agent to increase their inherent shear strength) that are more readily separated out by settling processes, removing not only the impurities but also the chemical additives. NotationThe residue so formed is categorised as aluminium sulfate (alum) or iron WTR material depending on the coagulant salt, with the former being the most widely used coagulant in the water treatment industry. Lime-softening sludge, composed of typically 80-95 wt% calcite (Raghu and Hsieh, 1986), is the result of softening hard water before its distribution as drinking water.Biosolids and sewage sludge materials are highly organic residue by-products of municipal waste water treatment, with the organic fraction originating principally from human faeces (primary sludge) and bacterial biomass (secondary sludge) and the inorganic fraction derived from materials such as soil, sediment and inorganic residuals (Haynes et al., 2009). According to the US Environmental Protection Agency (EPA) (2015), sewage sludge refers to the solids separated out during the treatment processes, whereas biosolids refers to treated sewage sludge material that meets regulatory pollutant-and pathogen-control requirements for land applica...

show abstract

Comparing Water Contents of Organic Soil Determined on the Basis of Different Oven-Drying Temperatures

O’Kelly

2018

Springer Series in Geomechanics and Geoengineering

View full text Add to dashboard Cite

show abstract

New Method to Determine the True Water Content of Organic Soils

Cited by 15 publications

References 4 publications

Drying temperature and water content–strength correlations

Drying temperature and water content–strength correlations

Geotechnics of municipal sludges and residues for landfilling

Comparing Water Contents of Organic Soil Determined on the Basis of Different Oven-Drying Temperatures

Contact Info

Product

Resources

About