Soil water repellency in sandy soil depends on the soil drying method, incubation temperature and specific surface area

Geoderma ◽  
2021 ◽  
Vol 402 ◽  
pp. 115264
Author(s):  
Enoch V.S. Wong ◽  
Philip R. Ward ◽  
Daniel V. Murphy ◽  
Matthias Leopold ◽  
Louise Barton
2013 ◽  
Vol 246 ◽  
pp. 504-510 ◽  
Author(s):  
Marcello Romagnoli ◽  
Magdalena Lassinantti Gualtieri ◽  
Miriam Hanuskova ◽  
Andrea Rattazzi ◽  
Costantino Polidoro

1994 ◽  
Vol 9 (9) ◽  
pp. 2272-2276 ◽  
Author(s):  
Yasuyuki Mizushima ◽  
Makoto Hori

Barium hexa-aluminate (BaO · 6Al2O3) aerogels were prepared using a supercritical drying method and their properties examined. A barium hexa-aluminate aerogel prepared from a double alkoxide of barium and aluminum showed a high specific surface area of 421 m2/g. Monolithic barium hexa-aluminate formed. No BaO · Al2O3 or alumina was observed, as is often the case in powder processing. The specific surface area of the monolithic barium hexa-aluminate fired at 1400 °C for 2 h was 12 m2/g, while that of the barium hexa-aluminate xerogel was only 0.8 m2/g. A barium hexa-aluminate aerogel was also prepared using barium by using a chelating agent. This aerogel showed a specific surface area of 454 m2/g as-dried. In the case of the chelating agent, BaO · Al2O3 was also detected along with barium hexa-aluminate after firing.


2007 ◽  
Vol 544-545 ◽  
pp. 673-676 ◽  
Author(s):  
Chang Yeoul Kim ◽  
Jong Kyu Lee ◽  
Byung Ik Kim

Aerogel has its advantages of light density of 0.003-0.35 g/cm3 and its high specific surface area, 600-1000m2/g, mean pore diameter ~20nm. However, aerogel has its disadvantages of fragility and high cost. To overcome the mechanical fragility, we synthesized aerogel composite blankets with glass wools by drying at ambient atmosphere. Colloidal silica sol was first prepared by ion exchanging sodium silicate through amberlite column. Then, glass wool was soaked into the pH-controlled silica aerogel and then gelated. Ageing of silica aerogel composite was conducted in purified water and solvent exchange/surface modification was simultaneously processed in hexane and TMCS solution. After drying at 60oC and heat-treatment at 230oC, we evaluated the properties of aerogel composite, its apparent density and specific surface area.


Geoderma ◽  
2019 ◽  
Vol 344 ◽  
pp. 108-118 ◽  
Author(s):  
Mary-Anne Lowe ◽  
Falko Mathes ◽  
Meng Heng Loke ◽  
Gavan McGrath ◽  
Daniel V. Murphy ◽  
...  

2020 ◽  
Vol 6 (10) ◽  
pp. 135-142
Author(s):  
S. Gurbanov

The article is devoted to the study of the regularity of changes in the specific surface of soil under the influence of agromeliorative measures, mainly irrigation and agrotechnical works carried out in the gray-brown soils of the Absheron Peninsula of Azerbaijan. Based on four years of experiments, it was determined that changes occur in the specific surface of the soil in the plowed layer as a result of the agromeliorative measures taken. Thus, a decrease in the specific surface area was observed in the 0–20 cm soil layer, and an increase in the specific surface area was observed in the 20–40 cm soil layer. In the first year of the experiments, the value of the average specific surface in the 0–20 cm soil layer was 3,098–3,988 cm2/g, and in the 20–40 cm soil layer it was 1,056–3,567 cm2 /g. However, after four years, the value of the special surface was 1,949–3,340 cm2/g in the 0–20 cm soil layer and 3,290–5,023 cm2/g in the 20–40 cm layer. The increase in the specific surface area in the lower layers of the soil is due to the gradual washing of dust, silt and colloidal particles from the plow layer to the lower layers. The reduction of the specific surface in the topsoil leads to the degradation of the topsoil, the deterioration of the water-physical properties, the formation of compaction below the topsoil, and ultimately the reduction of soil fertility. The article makes specific suggestions to prevent this process. It was also identified based on the calculations that the specific surface area of the soil, rich in silt, dust and colloidal particles, is many times larger than the specific surface area of sandy soil. The specific surface area of colloidal silt is 43,000 times larger than the specific surface area of dust and 130,000 times larger than the specific surface area of sand.


2012 ◽  
Vol 77 (1) ◽  
pp. 43-53 ◽  
Author(s):  
Emmanuel Arthur ◽  
Markus Tuller ◽  
Per Moldrup ◽  
Augustus C. Resurreccion ◽  
Mercer S. Meding ◽  
...  

Biologia ◽  
2013 ◽  
Vol 68 (6) ◽  
Author(s):  
Ľubomír Lichner ◽  
Jozef Capuliak ◽  
Natalia Zhukova ◽  
Ladislav Holko ◽  
Henryk Czachor ◽  
...  

AbstractPines, used for sand dune stabilization, can influence the hydrophysical parameters and water flow in an aeolian sandy soil considerably, mainly due to soil water repellency. Two sites, separated by distance of about 20 m, formed the basis of our study. A control soil (“Pure sand“) with limited impact of vegetation or organic matter was formed at 50 cm depth beneath a forest glade area. This was compared to a “Forest soil” in a 30-year old Scots pine (Pinus sylvestris) forest. Most of the hydrophysical parameters were substantially different between the two soil surfaces. The forest soil was substantially more water repellent and had two-times the degree of preferential flow compared to pure sand. Water and ethanol sorptivities, hydraulic conductivity, and saturated hydraulic conductivity were 1%, 84%, 2% and 26% those of the pure sand, respectively. The change in soil hydrophysical parameters due to soil water repellency resulted in preferential flow in the forest soil, emerging during a simulated heavy rain following a long hot, dry period. The wetting front established in pure sand exhibited a form typical of that for stable flow. Such a shape of the wetting front can be expected in the forest soil in spring, when soil water repellency is alleviated substantially.


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