Characterization of water repellency for hydrophobized grains with different geometries and sizes

Wijewardana, Nadeeka Senani; Kawamoto, Ken; Møldrup, Per; Komatsu, Toshiko; Kurukulasuriya, L. C.; Priyankara, Nadeej H.

doi:10.1007/s12665-015-4565-6

Cited by 22 publications

(23 citation statements)

References 36 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Measured values of WDPT on the PSO‐coated sands decreased with increasing grain size (Table 2), which is consistent with results for other hydrophobic coatings (Wijewardana et al., 2015). For a water droplet of a given size, entry into dry media will be controlled by the contact angle and the geometry of the air–water–solid interface.…”

Section: Discussionsupporting

confidence: 89%

“…The silane-based treatments used in previous work result in extreme hydrophobicity (Chan & Lourenço, 2016) and would be of limited utility for large-scale agriculture; polymerized plant oils (de Espinosa & Meier, 2011) have potential as a low-cost and renewable alternative. Preliminary laboratory tests have shown it possible to create a loose hydrophobic mulch by coating agricultural waste products with fast-drying linseed oil that polymerizes at room temperature (Vaicekauskaite et al, 2019). The polymerization of slow-drying vegetable oils (e.g., soybean [Glycine max (L.) Merr.])…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Mildly hydrophobic biobased mulch: A sustainable approach to controlling bare soil evaporation

Barnes

Nicholl

2020

Vadose Zone Journal

View full text Add to dashboard Cite

Mulching with polyethylene film is the conventional approach to decrease evaporative water loss from agricultural soils, but it is not environmentally sustainable. In this study, a laboratory experiment was conducted to test the potential utility of partially polymerized soybean oil (PSO) coated sands as a surface treatment to reduce bare soil evaporation. Evaporation was tracked for 23.8 d from saturated sand columns treated with a surface layer (1 or 2 cm) of either coated medium sand (MS-PSO) or coated coarse sand (CS-PSO). The water drop penetration time (WDPT) was used to assess the hydrophobicity of fresh PSO-coated sands; the saturated hydraulic conductivity (K s) and particle density (ρ s) were measured as well. The WDPT was also tested on MS-PSO and CS-PSO samples aged in four separate environmental conditions for 20-21 d. Both PSO-coated sands were mildly hydrophobic, and the surface treatment layers reduced evaporative loss by 83-96% over bare soil, which is similar to previous work using extremely hydrophobic chemically treated sands. Freshly coated MS-PSO had a higher WDPT score and lower K s than CS-PSO. After the environmental aging tests, the MS-PSO and CS-PSO samples remained mildly hydrophobic. Notably, CS-PSO had a low initial WDPT (∼1.09 to ∼2.58 s) and a high K s (2.66 × 10 −1 cm s −1), suggesting coarse PSO-coated sands will permit infiltration. Given these findings, PSO-coated sand has the potential to be developed into a sustainable alternative to polyethylene film mulch.

show abstract

Section: Discussionsupporting

confidence: 89%

Section: Introductionmentioning

confidence: 99%

Mildly hydrophobic biobased mulch: A sustainable approach to controlling bare soil evaporation

Barnes

Nicholl

2020

Vadose Zone Journal

View full text Add to dashboard Cite

show abstract

“…Since the water-repellent clays were not easily wetted, the soil samples were prepared by thoroughly mixing with a deionized water for 30 min and then stored in a sealed plastic bag for 24 h before the compaction test. This procedure assures a more homogenous distribution of water in the water-repellent soil specimens [ 35 , 36 ]. The wetted soil was placed in three layers into the mold and each layer was compacted by 25 blows of the rammer with a falling height of 305 mm.…”

Section: Methodsmentioning

confidence: 99%

Engineering Characteristics of Chemically Treated Water-Repellent Kaolin

et al. 2016

View full text Add to dashboard Cite

Water-repellent soils have a potential as alternative construction materials that will improve conventional geotechnical structures. In this study, the potential of chemically treated water-repellent kaolin clay as a landfill cover material is explored by examining its characteristics including hydraulic and mechanical properties. In order to provide water repellency to the kaolin clay, the surface of clay particle is modified with organosilanes in concentrations (CO) ranging from 0.5% to 10% by weight. As the CO increases, the specific gravity of treated clay tends to decrease, whereas the total organic carbon content of the treated clay tends to increase. The soil-water contact angle increases with an increase in CO until CO = 2.5%, and then maintains an almost constant value (≈134.0°). Resistance to water infiltration is improved by organosilane treatment under low hydrostatic pressure. However, water infiltration resistance under high hydrostatic pressure is reduced or exacerbated to the level of untreated clay. The maximum compacted dry weight density decreases with increasing CO. As the CO increases, the small strain shear modulus increases, whereas the effect of organosilane treatment on the constrained modulus is minimal. The results indicate that water-repellent kaolin clay possesses excellent engineering characteristics for a landfill cover material.

show abstract

“…Similarly, in drought-prone environments, an upper water repellent layer of soil has proven to act as an effective mulch, as it helps to reduce the capillary rise of water and subsequently lowers losses via evaporation (Wallis and Horne, 1992;Rye and Smettem, 2017). Wijewardana et al (2015) discusses the successful use of water repellent grains in Capillary Barrier Cover Systems (CBCSs), which are used to prevent water infiltration and limit seepage at waste landfill sites. Jordan et al (2017) also suggested the use of silanised soils to help provide a water repellent barrier for uses in geoenvironmental engineering, similar to those described by Wijewardana et al (2015).…”

Section: Beneficial Uses Of Soil Water Repellencymentioning

confidence: 99%

“…Wijewardana et al (2015) discusses the successful use of water repellent grains in Capillary Barrier Cover Systems (CBCSs), which are used to prevent water infiltration and limit seepage at waste landfill sites. Jordan et al (2017) also suggested the use of silanised soils to help provide a water repellent barrier for uses in geoenvironmental engineering, similar to those described by Wijewardana et al (2015). Mainwaring (2004) noted that some plants in areas prone to water repellency have adapted over time to the extreme conditions.…”

Section: Beneficial Uses Of Soil Water Repellencymentioning

confidence: 99%

New approaches to the study of hydrophobicity and wetting of soils: methods and theories

Balshaw¹

View full text Add to dashboard Cite

New approaches to the study of hydrophobicity and wetting of soils were investigated with the following research objectives: 1) to evaluate the use of fluorescence probes, nile red and pyrene, as tools to assess the polarity and viscosity of organics adsorbed to soils; 2) to assess, using a variety of kinetic methods, what steps are involved in wetting soils; and 3) to assess the validity of current theories for the anomalously high contact angles often measured for water on soils, and investigate an alternative explanation based on the geometry of a water drop sitting on hydrophobic particles. Whilst it was possible to image nile red emission after adsorption to soils, issues of emission intensity and soil auto-luminescence suggest that nile red is not a useful probe for soil studies. Fluorescence measurements were made using pyrene as an in-situ polarity and viscosity/mobility probe. Using pyrene co-deposited with organics on acid-washed sand, excimer kinetics showed a decrease in environment mobility as the organic layer was changed from a liquid to a hard wax. Spectra from natural soils indicated varying environmental polarity and heterogeneity within the soil samples studied. A theoretical model for soil wetting, involving adhesional-immersional wetting followed by branching capillary wetting, is proposed, and a series of experiments to assess the validity of this model described. Methods used include: water drop penetration time (WDPT) test, mass of soil grains wetted over time; time taken for penetration of a water drop into different soil thicknesses; optical microscopy; WDPT measurements with salt solutions of different densities. An alternative interpretation of the anomalously high contact angles measured on soils is proposed based on a correction factor for water on particles. To assess this, measurements were made using regularly arranged ballpoint needles and metal spheres, and acid-washed sand and natural soil, coated in paraffin wax. .

show abstract

Characterization of water repellency for hydrophobized grains with different geometries and sizes

Cited by 22 publications

References 36 publications

Mildly hydrophobic biobased mulch: A sustainable approach to controlling bare soil evaporation

Mildly hydrophobic biobased mulch: A sustainable approach to controlling bare soil evaporation

Engineering Characteristics of Chemically Treated Water-Repellent Kaolin

New approaches to the study of hydrophobicity and wetting of soils: methods and theories

Contact Info

Product

Resources

About