Premium
Forced gas injection and water infiltration into sand — A two‐phase flow barrel and column experiment
Author(s) -
BenNoah Ilan,
Nitsan Ido,
Friedman Shmulik P.
Publication year - 2021
Publication title -
soil science society of america journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.836
H-Index - 168
eISSN - 1435-0661
pISSN - 0361-5995
DOI - 10.1002/saj2.20138
Subject(s) - aeration , soil water , infiltration (hvac) , environmental science , soil science , water flow , secondary air injection , environmental engineering , hydrology (agriculture) , chemistry , materials science , geotechnical engineering , geology , waste management , organic chemistry , engineering , composite material
Soil aeration (i.e., soil air content and composition) is of major importance in agricultural and environmental practices. Poor aeration reduces plant growth, development, yield, and resistance to diseases and other abiotic stresses (e.g., salinity). In many soils contaminated with hydrocarbons, low O 2 supply limits the rate of contaminant decomposition and prolongs remediation. Soil aeration is governed by diffusion of O 2 from the atmosphere and countercurrent diffusion of CO 2 to the atmosphere. Injection of air (with an atmospheric O 2 concentration of 20.9%) into poorly aerated soils is expected to improve soil aeration by enriching it with O 2 and extracting CO 2 . In addition, air flow causes redistribution of soil water. Water redistribution is affected by operational (discharge rate, frequency, duty cycle) and geometrical (depth and distance between sources) air injection parameters, soil parameters (e.g., water retention and conductivity), and irrigation geometry and scheduling. We studied forced one‐ and three‐dimensional air (or N 2 ) and water injection into packed wet sand and analyzed the effect of air injection on soil aeration and water redistribution in granular media. The study demonstrates the applicability of the Darcy–Buckingham law to air flow at different degrees of water saturation and for a large relevant range of capillary numbers. We also suggest a simple method to measure the soil's conductivity to air (Darcy's constant) for different air contents and use a simple analytical solution to estimate O 2 diffusion from the atmosphere. We discuss the effect of operational air injection parameters on aeration's effectiveness and efficiency.