Journal of Water and Wastewater Science and Engineering

Journal of Water and Wastewater Science and Engineering

Optimization of Bioremediation Alternatives in Petroleum-Contaminated Aquifers: A Case Study of Shiraz Oil Refinery

Document Type : Original Article

Authors
Soroush Amirakbari 1
Saeed Alimohammadi 2
1 Ph.D. Student, Faculty of Civil, Water and Environmental Engineering, Shahid Beheshti University, Tehran, Iran.
2 Associate Professor, Faculty of Civil, Water and Environmental Engineering, Shahid Beheshti University, Tehran, Iran.
10.22112/jwwse.2025.485324.1416
Abstract
In this study, a simulation-optimization model was developed to minimize the cost of bioremediation in a petroleum-contaminated aquifer. Groundwater flow and contaminant transport were simulated using MODFLOW6 and MT3D-USGS, while bioremediation optimization was performed using the differential evolution algorithm. The accuracy of the modeling approach was verified through a benchmark test. Subsequently, the Shiraz Oil Refinery was selected as a case study, and the remediation of BTEX (benzene, toluene, ethylbenzene, and xylene) contamination resulting from a potential spill was evaluated under four scenarios. The results of Scenario 1 indicated that natural bioremediation alone could not reduce benzene concentrations to the regulatory limit. The other three scenarios were defined based on the location, number of bioremediation wells, and remediation duration. In all three cases, the contaminant concentration was reduced below the regulatory standard by the end of the ten-year period. Optimization results showed that Scenario 2 (with two injection wells and two extraction wells over four years) had the lowest total cost of $157,634, making it 12.1% cheaper than Scenario 3 and 9.5% cheaper than Scenario 4. In contrast, Scenario 3 exhibited the fastest remediation rate. In summary, Scenario 2 was the most cost-effective option due to its lower bioremediation cost and lower pumping and injection rates over a longer duration, whereas Scenario 3 was more effective in achieving rapid remediation.
Keywords
Groundwater remediation
BTEX
Bioremediation
Shiraz refinery
Differential evolution algorithm
MODFLOW6
MT3D-USGS
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Journal of Water and Wastewater Science and Engineering
Volume 11, Issue 1
Spring 2026
Pages 17-32

  • Receive Date 03 November 2024
  • Revise Date 28 April 2025
  • Accept Date 26 May 2025