Study of aqueous and non-aqueous phase liquid in fractured double-porosity soil using digital image processing

Abstract

The leakage and spillage of non-aqueous phase liquids (NAPLs) and aqueous phase liquids (APLs) contribute to groundwater contamination, resulting in groundwater pollution and rendering the quality of groundwater unsafe for drinking and agriculture. Ensuring the availability and sustainable management of water and sanitation for all was the goal and target of the 2030 United Nations agenda for sustainable development, consisting of a plan of action for the population, the planet and general prosperity. This paper is intended to investigate the aqueous and non-aqueous phase liquid migrations in a deformable double-porosity soil, which has become important for both sustainable groundwater use and the comprehensive understanding of the behaviour of liquid migration into groundwater. A modelling experiment was conducted in an attempt to study the pattern and behaviour of aqueous and non-aqueous phase liquid migration in fractured double-porosity soil using a digital image processing technique. The results of the experiments show that the flow of the APL and NAPL migration was not uniformly downward. Faster migration occurred where the soil surface was cracked compared to other locations where the soil surface was not cracked, even when liquids such as toluene were not used. It was concluded that the factors that significantly influenced the APL and NAPL migration were the structure of the soil sample, fracture pattern of the soil sample, physical interaction i.e. bonding between the liquid and soil sample, and the capillary pressure of the fluid. This study indicates that digital image analysis can provide detailed information to help researchers better understand and be able to simulate the pattern and characteristics of liquid migration that have an influence on groundwater resources.