An approach to remediation of a tropical aquifer contaminated with hydrocarbons

This paper deals about an approach to remediation for treating soils and groundwater contaminated with hydrocarbons in a tropical aquifer caused because of leaks from underground tanks in a gas station of Venezuela. Ex situ and in situ remediation treatment options were designed, recommending the ex situ remediation due to microbial inhibition produced by the presence of heavy metals and multiple strata with different soil materials in the interface between the unsaturated and saturated zones, where the most significant hydrocarbon concentrations were found. Under these conditions, ex situ bioremediation option based on two coupled bioreactors can overcome environmental limiting factors by optimizing temperature, oxygen supply, nutrient status, contaminant bioavailability, and microbial population. Ex situ remediation included for soil treatment, a Soil‐Slurry Sequencing Batch Reactor (SS‐SBR) and Upflow Anaerobic Filter separated in three phases (UAF‐3SS). For groundwater treatment SBR‐UAF‐3SS sequence was established. The first phase was represented by SS‐SBR for ex situ bioremediation of soils, configuring COD removal efficiency of 80%. It was set that SS‐SBR performs functions for groundwater treatment operating as SBR, removing 60% COD. For the second phase, an upflow anaerobic filter separate in three phases (UAF‐3SS) designed to ensure 99% COD removal efficiency.