Experimental study on the transport characteristics of buried pipeline leakage and the performance of groundwater remediation system.

Enhanced understanding of light non-aqueous phase liquid (LNAPL) infiltration into sandy porous medium is significant to the effective design of remediation strategies. A system for buried pipeline leakage in 2-D sandbox was conducted to investigate the migration of diesel through a sandy porous medium, and the system could also be conducted to investigate groundwater remediation. Two groups of experiments were carried out. The first experiment consisted of diesel infiltration into a fine sand matrix. We could notice that diesel spilled in dry sand layer at a constant speed and the diesel front kept longitudinal movement due to the gravity before it arrived at the edge of the capillary zone. The diesel front broadened as a whole because of the capillary force jacking after it reached the capillary zone. Finally, the bulk of the diesel was contained on top of the capillary zone. To protect groundwater, the second experiment consisted of remediating soils and groundwater. The results indicated that the voltage of electrocoagulation apparatus had a great influence on the treatment effect, and the removal rate of diesel was found to be more than 90% with a constant voltage of 20 V. The efficiency of groundwater remediation was influenced by the flow velocity, and it took 11 h when the flow velocity was 2.089 L/min. To summarize, the research was conducive to the study on diesel pollution control and pollution prediction.