Bioremediation of Crude Oil Contaminated Desert Soil: Effect of Biostimulation, Bioaugmentation and Bioavailability in Biopile Treatment Systems.

Farid Benyahia,Ahmed Embaby

doi:10.3390/ijerph13020219

Abstract

This work was aimed at evaluating the relative merits of bioaugmentation, biostimulation and surfactant-enhanced bioavailability of a desert soil contaminated by crude oil through biopile treatment. The results show that the desert soil required bioaugmentation and biostimulation for bioremediation of crude oil. The bioaugmented biopile system led to a total petroleum hydrocarbon (TPH) reduction of 77% over 156 days while the system with polyoxyethylene (20) sorbitan monooleate (Tween 80) gave a 56% decrease in TPH. The biostimulated system with indigenous micro-organisms gave 23% reduction in TPH. The control system gave 4% TPH reduction. The addition of Tween 80 led to a respiration rate that peaked in 48 days compared to 88 days for the bioaugmented system and respiration declined rapidly due to nitrogen depletion. The residual hydrocarbon in the biopile systems studied contained polyaromatics (PAH) in quantities that may be considered as hazardous. Nitrogen was found to be a limiting nutrient in desert soil bioremediation.

Highlights

Bioremediation of soils contaminated by hydrocarbons is an established method these days and has been put in practice in several ways such as “in-situ” or “ex-situ” technologies [1,2,3,4,5]
For instance a recent paper by Roy et al [3] indicated that up to 39 native crude oil degrading bacteria can be found at contaminated sites and that these were dominated by the Pseudomonas genus
In virtually all cases of field tests of bioremediation in the literature either native or naturally occurring bacteria added in the bioremediation treatment have been used

Summary

Introduction

Bioremediation of soils contaminated by hydrocarbons is an established method these days and has been put in practice in several ways such as “in-situ” or “ex-situ” technologies [1,2,3,4,5]. The effectiveness of soil bioremediation, both technical and economic, has been much debated and is still the subject of numerous research investigations. This stems from the fact that soils, soils constituents and contaminants vary to a great extent, making interactions and dependencies between these extremely complicated. Some of these intricacies have been reviewed recently [4]. In virtually all cases of field tests of bioremediation in the literature either native or naturally occurring bacteria added in the bioremediation treatment have been used. The idea of using “genetically engineered” micro-organisms still face regulatory hurdles because of the unknown consequences that may ensue the release in nature of such manipulated micro-organisms [4]

Objectives

Methods

Results