Evaluation of LNAPL Behavior in Water Table Inter-Fluctuate Zone under Groundwater Drawdown Condition

• Published in: Water (Basel) Vol. 12; no. 9; p. 2337
• Main Authors: Azimi, Reza, Vaezihir, Abdorreza, Lenhard, Robert, Hassanizadeh, S.
• Format: Journal Article
• Language: English
• Published: Basel MDPI AG 01-09-2020
• Subjects: Aquifers; Cell size; Contamination; Crude oil; Drawdown; Environmental monitoring; Experiments; Grain size; Groundwater; groundwater level fluctuations; Injection; Interfaces; Laboratories; LNAPL; Mathematical models; Monitoring; Multiphase flow; Numerical models; Permeability; Pumping; sand tank; Thickness; Water flow; Water levels; Water table
• ISSN: 2073-4441; 2073-4441
• DOI: 10.3390/w12092337

We investigate the movement of LNAPL (light non-aqueous phase liquid) into and out of monitoring wells in an immediate-scale experimental cell. Aquifer material grain size and LNAPL viscosity are two factors that are varied in three experiments involving lowering and rising water levels. There are six monitoring wells at varying distances from a LNAPL injection point and a water pumping well. We established steady water flow through the aquifer materials prior to LNAPL injection. Water pumping lowered the water levels in the aquifer materials. Terminating water pumping raised the water levels in the aquifer materials. Our focus was to record the LNAPL thickness in the monitoring wells under transient conditions. Throughout the experiments, we measured the elevations of the air-LNAPL and LNAPL-water interfaces in the monitoring wells to obtain the LNAPL thicknesses in the wells. We analyze the results and give plausible explanations. The data presented can be employed to test multiphase flow numerical models.