BTEX Extraction from Clay Soil Using Prefabricated Vertical Drains

Abstract

A pilot scale field test was conducted to demonstrate the feasibility of using prefabricated vertical drains (PVDs) for in-situ point extraction of benzene, toluene, ethylbenzene, and xylene (BTEX) under vacuum. Results indicated the achievement of an average flow rate of 16.7 mL/s for the five PVD systems. Grab samples from the effluent indicated an increase in retrieved BTEX concentration with time. Maximum retrieved concentrations in a 2-day period were ∼0.4 mg/L for benzene, 0.27 mg/L for toluene, 0.19 mg/L for ethylbenzene, and 0.025 mg/L for xylene. Based on the limited results of the pilot scale test, a full-scale remediation of the site using the PVDs system is deemed feasible.