LNAPL Migration in Vadoze Zone and Its Prevention Using Natural Fiber

Abstract

Light non-aqueous phase liquids (LNAPLs) spilt over an area can be a persistent and long-term source of groundwater contamination. Once the groundwater gets contaminated, it is difficult to remediate. Migration of the spilt LNAPL should be contained within the unsaturated zone of the soil such that the LNAPL does not reach the groundwater source. Although the presence of LNAPLs in the unsaturated zone is also a long-term source, the provision of proper liners can contain the LNAPL within this region. The use of natural fiber as a liner in the unsaturated zone can be a sustainable solution to this problem if it can effectively contain the LNAPL. The objective of the present study was to investigate whether the use of natural fiber (coir geotextile) has supplemented the inherent attenuation characteristics of soils in the unsaturated zone thereby controlling the LNAPL migration. The study reveals that coir geotextiles were more effective in reducing the LNAPL migration in laterite soil than in sandy soil. Coir geotextiles are effective in controlling the migration of LNAPL if these are embedded in the soil with permeability less than 2.30 × 10−05 m/s.

Keywords

• coir geotextile
• groundwater contamination
• hydrocarbons
• image analysis technique
• napl
• natural fiber