This document summarizes a study on bioremediating petroleum contaminated soils through an on-site composting process. Soil samples from an oil and gas site in Iran were analyzed and sorted into categories based on contamination levels. The soils were then co-composted in piles for 8 weeks. Samples analyzed over time showed reductions in total petroleum hydrocarbons of up to 98.9% across piles. After treatment, the soils met regulatory standards and were returned to the environment, demonstrating an effective process for resource recovery from contaminated sites.

1. Bioremediation of petroleum contaminated solids integrating on site composting
Amir Parnian1, Amin Parnian2, James N. Furze3,4
1 National Salinity Research Center (NSRC), Yazd, Iran. 2 Young Researchers Club, Islamic Azad
University, Iran. 3 Laboratory of Biotechnology and Valorization of Natural Resources, Ibn Zohr
University, Morocco. 4 Control and Systems Engineering Department, University of Technology-Iraq, Iraq

2. Fig. 1 Petroleum waste, Khuzestan, Iran, 2020: a) compressed solids and muds opposite huge piles of drilling waste; b) high salinity /
oil in water bodies; c) contamination following a transfer pipe incident; d) contamination of over 40000m2 (Parnian et al. 2020)
a
c d
b

3. Fig. 2 Site location, Khuzestan province, Iran, 2020
Fig. 3 Co-composting plan (Khan et al. 2004; Parnian et al. 2022)

4. Fig. 4 The restricted area of Arvandan Oil and Gas Company, Jofeir region, Hoveizeh county, Khuzestan province,
Iran, 2020: a) Irrigation of the mixture with road-construction machinery; b) aeration of the mixture with road-
construction machinery
EC
(dS m-1)
pH
TPH
(g kg-1)
Water repellency (S)
Moderately polluted 18.6 ± 1.2 6.95 ± 0.23 6.9-7.4 1500-2500
Highly polluted 17.3 ± 2.0 7.00 ± 0.20 9.6-12.8 8000-9500
Very highly polluted 19.1 ± 1.5 7.05 ± 0.15 15.6-17.1 10500-12500
EC: Electrical conductivity, TPH: total petroleum hydrocarbons. Standard error (±SE) is used for means comparison (n=5)
Table 1 Physical-chemical characteristics of the contaminated soils before treatment

5. Time (days) 7 14 21 28 35 42 49 56
Moderately
polluted pile
66.26e 79.01d 87.24c 91.32b 94.03b 94.16b 96.09a 98.60a
Highly
polluted pile
40.80d 82.52c 83.28c 91.55b 95.25a 95.32a 96.61a 98.77a
Very highly
polluted pile
53.99e 84.23d 89.18c 94.14b 96.47a 96.86a 97.17a 98.90a
Different letters in the same row indicate a significant difference at P < 0.05, n = 3.
Fig. 5 TPH reduction (±SD, n=5) in different piles during 8 weeks
of co-composting.
Fig. 6 Temperature of the piles during the bioremediation
process
Table 2 Bioremediation efficiency percentage of the soils during the co-composting process
TPH
(g
kg
-1
)
Temperature
(
o
C)
Time (days) Time (days)

6. Table 3 Contaminants concentration in mixed soil samples before and after the co-composting treatment
Name Vinyl
Chloride
Hexane Heptane Octane Vinyl Banzene Mineral
Oil
Benzo (g,h,i)
perylene
Dibenzo (a,h)
antbracene
Indeno (1,2,3-
ed) pyrene
IC 0.05 0.693 1.773 2.952 0.05 1329 1.98 3.35 8.6
FC - - - - - 12 - - -
Benzo (a)
perylene
Benzo (k)
fluoranthene
Benzo (b)
fluoranthene
Chrysene Benzo (a)
anthracene
Pyrene Fluoranthene Anthracene Phenanthrene
IC 6.25 1.86 2.73 2.66 9.85 12.7 10.4 17.15 84
FC - - - - - - - - 5
Flourene Acenaphtene Acenaphthylene Naphthal
ene
Xylenes Ethl
Benzne
Toluene Benzene
IC 11 5.35 11.3 1.55 12.8 6.28 1.89 12.4
FC - - - - 2.3 - - 1.2
Nine samples were collected from soils and examined as one mix sample, using Varian CP-3800 Gas Chromatograph; IC: Initial Concentration (mg kg-1); FC: Final Concentration (mg kg-1)
Fig. 7 Resource recovery: a) recovered soil; b) road construction machinery spreading soil to the surrounding environment (Parnian et al. 2022)

7. Acknowledgments
We thank employees of Parnian Sazeh Chehelsotoun Co. Ltd. of Iran whose diligent work and support enabled
the resource recovery shown here. The authors also wish to express gratitude to the CEO of the company, Mr.
Reza Parnian.
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References
• Khan FI, Husain T, Hejazi R (2004) An overview and analysis of site remediation technologies. J Environ
Manage 71(2):95-122. https://doi.org/10.1016/j.jenvman.2004.02.003
• Parnian A, Furze JN, Parnian A (2020) Water out of waste–solar-desalination-humidification-
dehumidification auxiliaries processing extractive industrial operations. Water Productivity Journal 1(1): 31-
38. https://doi.org/10.22034/wpj.2020.119474
• Parnian A, Parnian A Pirasteh-Anosheh H et al (2022) Full-scale bioremediation of petroleum contaminated
soils via integration of co-composting. J Soils Sediments. https://doi.org/10.1007/s11368-022-03229-5