10.57647/ijeee.2026.1701.05

Quantification of Microplastics and Total Petroleum Hydrocarbons in Seawater and Sediments of the Southwestern Caspian Sea

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  • Roghayeh Shahbazi1,
  • Ebrahim Fataei1,
  • Ali Mehdinia2,
  • Maryam Hazrati Niari3,
  • Hossein Saadati1,
  1. Department of Environmental Science and Engineering, Ard.C., Islamic Azad University, Ardabil, Iran
  2. ranian National Institute for Oceanography and Atmospheric Science, Tehran, 1411813389, Iran
  3. Lung Diseases Research Center, Ardabil University of Medical Sciences, Ardabil, Iran

Received: 2025-11-14

Revised: 2026-01-25

Accepted: 2026-02-12

Published in Issue 2026-03-31

Copyright (c) 2026 Roghayeh Shahbazi, Ebrahim Fataei, Ali Mehdinia, Maryam Hazrati Niari, Hossein Saadati (Author)

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This work is licensed under a Creative Commons Attribution 4.0 International License.

How to Cite

Shahbazi, R., Fataei, E., Mehdinia, A., Hazrati Niari, M., & Saadati, H. (2026). Quantification of Microplastics and Total Petroleum Hydrocarbons in Seawater and Sediments of the Southwestern Caspian Sea. International Journal of Energy and Environmental Engineering, 17(01). https://doi.org/10.57647/ijeee.2026.1701.05
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Abstract

Coastal environments are increasingly threatened by emerging contaminants; however, integrated assessments of multiple pollutant classes remain scarce. This study provides a simultaneous investigation of microplastics (MPs) and total petroleum hydrocarbons (TPHs) in seawater and sediments along the southwestern coast of the Caspian Sea. Samples were collected from fourteen coastal stations during the dry season. MPs were characterized by type, size, shape, color, and polymer composition using microscopy and Raman spectroscopy, while TPHs were quantified using GC-MS. The results revealed MP abundances ranging from 0.05 to 2.35  articles L⁻¹ in water and from 2.01 to 24.13 particles kg⁻¹ in sediment. Fibers and fragments in the 100–500 μm size class were dominant, with polyethylene (PE) and polyethylene terephthalate (PET) identified as the most prevalent polymers. TPH concentrations varied from not detected to 20.152 μg L⁻¹ in water and from 8.37 to 1835.29 μg kg⁻¹ in sediment. Spatial analysis showed no overlap between the contamination hotspots of MPs and TPHs, indicating distinct sources and transport pathways. This concurrent assessment underscores a complex contamination profile in the region and highlights potential ecological risks from both physical and chemical stressors. The  distinct spatial patterns provide critical information for designing targeted pollution control measures.

Keywords

  • Microplastics,
  • Petroleum pollution,
  • ediments pollutant,
  • Water pollutants,
  • Caspian sea
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References

  1. Niari, M.H., Takdastan, A., Babaei, A., Dobaradaran, S., Jorfi, S. and Ahmadi, M. (2024). Fate and ecological risk of phthalate esters in microplastics of wastewater in the wastewater treatment plant. Water, Air, & Soil Pollution, 235, pp. 106.
  2. Thanigaivel, S., Kamalesh, R., Ragini, Y., Saravanan, A., Vickram, A., Abirami, M. and Thiruvengadam, S. (2025). Microplastic pollution in marine environments: An in-depth analysis of advanced monitoring techniques, removal technologies, and future challenges. Marine Environmental Research, pp. 106993.
  3. Niari, M.H., Ghobadi, H. and Aslani, M.R. (2025). Quantification of microplastics and phthalate esters in nasal lavage fluid of hospital employees after face mask use. Water, Air, & Soil Pollution, 236, pp. 130.
  4. Cole, M., Lindeque, P., Halsband, C. and Galloway, T.S. (2011). Microplastics as contaminants in the marine environment: a review. Marine Pollution Bulletin, 62, pp. 2588–2597.
  5. Nematollahi, M.J., Moore, F., Keshavarzi, B., Vogt, R.D., Saravi, H.N. and Busquets, R. (2020). Microplastic particles in sediments and waters, south of Caspian Sea: Frequency, distribution, characteristics, and chemical composition. Ecotoxicology and Environmental Safety, 206, pp. 111137.
  6. Manbohi, A., Mehdinia, A., Rahnama, R. and Dehbandi, R. (2021). Microplastic pollution in inshore and offshore surface waters of the southern Caspian Sea. Chemosphere, 281, pp. 130896.
  7. Wright, S.L., Thompson, R.C. and Galloway, T.S. (2013). The physical impacts of microplastics on marine organisms: a review. Environmental Pollution, 178, pp. 483–492.
  8. Nawaz, F., Islam, Z.U., Ghori, S.A., Bahadur, A., Ullah, H., Ahmad, M. and Khan, G.u. (2025). Microplastic and nanoplastic pollution: Assessing translocation, impact, and mitigation strategies in marine ecosystems. Water Environment Research, 97, pp. e70032.
  9. Foshtomi, M.Y., Oryan, S., Taheri, M., Bastami, K.D. and Zahed, M.A. (2019). Composition and abundance of microplastics in surface sediments and their interaction with sedimentary heavy metals, PAHs and TPH (total petroleum hydrocarbons). Marine Pollution Bulletin, 149, pp. 110655.
  10. Bakir, A., Rowland, S.J. and Thompson, R.C. (2014). Enhanced desorption of persistent organic pollutants from microplastics under simulated physiological conditions. Environmental Pollution, 185, pp. 16–23.
  11. Chen, C.-L. (2015). Regulation and management of marine litter. In Marine Anthropogenic Litter, Springer International Publishing, Cham, pp. 395–428.
  12. Zhong, L., Wang, R., Wang, P., Yu, G., Song, Y. and Sun, F. (2025). Enhanced remediation of petroleum in soil by petroleum-degrading bacterium strain TDYN1 and the effects of microplastics. Bulletin of Environmental Contamination and Toxicology, 114, pp. 81.
  13. Emadi Jamali, M., Mousavi Nadushan, R., Javid, A.H., Mashinchiyan Moradi, A. and Givianrad, M.H. (2020). Spatial trends of Total Petroleum Hydrocarbons, related heavy metals and sediment characteristics in South Caspian Sea: Effect of depth and temporal dispersions. Iranian Journal of Fisheries Sciences, 19, pp. 3221–3238.
  14. Lundgreen, K., Holbech, H., Pedersen, K.L., Petersen, G.I., Andreasen, R.R., George, C., Drillet, G. and Andersen, M. (2018). UV fluences required for compliance with ballast water discharge standards using two approved methods for algal viability assessment. Marine Pollution Bulletin, 135, pp. 1090–1100.
  15. Gholizadeh, M. and Cera, A. (2022). Microplastic contamination in the sediments of Qarasu estuary in Gorgan Bay, south-east of Caspian Sea, Iran. Science of the Total Environment, 838, pp. 155913.
  16. Manbohi, A., Mehdinia, A., Rahnama, R., Hamzehpour, A. and Dehbandi, R. (2023). Sources and hotspots of microplastics of the rivers ending to the southern Caspian Sea. Marine Pollution Bulletin, 188, pp. 114562.
  17. Gholizadeh, M., Bagheri, T., Harsij, M., Danabas, D., Zakeri, M.A.M. and Siddique, M.A.M. (2024). Assessment of microplastic contamination in some commercial fishes of the southern Caspian Sea and its potential risks. Environmental Science and Pollution Research, 31, pp. 26006–26018.
  18. Razeghi, N., Hamidian, A.H., Wu, C., Zhang, Y. and Yang, M. (2021). Microplastic sampling techniques in freshwaters and sediments: a review. Environmental Chemistry Letters, 19, pp. 4225–4252.
  19. Stock, F., Kochleus, C., Bänsch-Baltruschat, B., Brennholt, N. and Reifferscheid, G. (2019). Sampling techniques and preparation methods for microplastic analyses in the aquatic environment–A review. TrAC Trends in Analytical Chemistry, 113, pp. 84–92.
  20. Niari, M.H., Ghobadi, H., Amani, M., Aslani, M.R., Fazlzadeh, M., Matin, S., Takaldani, A.H.S. and Hosseininia, S. (2025). Characteristics and assessment of exposure to microplastics through inhalation in indoor air of hospitals. Air Quality, Atmosphere & Health, 18, pp. 253–262.
  21. Elkhatib, D. and Oyanedel-Craver, V. (2020). A critical review of extraction and identification methods of microplastics in wastewater and drinking water. Environmental Science & Technology, 54, pp. 7037–7049.
  22. Takdastan, A., Niari, M.H., Babaei, A., Dobaradaran, S., Jorfi, S. and Ahmadi, M. (2021). Occurrence and distribution of microplastic particles and the concentration of Di 2-ethyl hexyl phthalate (DEHP) in microplastics and wastewater in the wastewater treatment plant. Journal of Environmental Management, 280, pp. 111851.
  23. Balasubramaniam, D.A., Panneerselvam, R., Akshaya, K., Rajamanickam, R., De-la-Torre, G.E. and Selvasembian, R. (2024). The advancements and detection methodologies for microplastic detection in environmental samples. In Microplastics: Environmental Pollution and Degradation Process, Springer, pp. 207–224.
  24. Chen, H., Jiang, F., Li, J., Cao, W., Zhang, D., Zhang, F., Wang, S. and Sun, C. (2025). Interlinked water and sediment microplastics in the Laizhou Bay of China. Journal of Oceanology and Limnology, 43, pp. 446–458.
  25. Niari, M.H., Jaafarzadeh, N., Dobaradaran, S., Niri, M.V. and Dargahi, A. (2023). Release of microplastics to the environment through wastewater treatment plants: Study on four types of wastewater treatment processes. Water, Air, & Soil Pollution, 234, pp. 589.
  26. Samaei, S.H.-A., Mojahednia, P., Chen, J., Li, Z., Jaszczyszyn, K., Kiedrzyńska, E. and Xue, J. (2025). What Does the “Trojan Horse” Carry? The Pollutants Associated with Microplastics/Nanoplastics in Water Environments. ACS ES&T Water, 5, pp. 1530–1545.
  27. Abdykarimov, B., Alimzhanova, M., López-Serna, R. and Syrgabek, Y. (2025). Green Analytical Procedure Index Assessment for Total Petroleum Hydrocarbons Determination Methods in Soil and Sediments. A Review. Trends in Environmental Analytical Chemistry, pp. e00262.
  28. Sánchez-Campos, M., Ponce-Vélez, G., Sanvicente-Añorve, L. and Alatorre-Mendieta, M. (2024). Microplastic contamination in three environmental compartments of a coastal lagoon in the southern Gulf of Mexico. Environmental Monitoring and Assessment, 196, pp. 1012.
  29. Firdaus, M., Trihadiningrum, Y. and Lestari, P. (2020). Microplastic pollution in the sediment of Jagir estuary, Surabaya City, Indonesia. Marine Pollution Bulletin, 150, pp. 110790.
  30. Zhang, M., Lin, Y., Booth, A.M., Song, X., Cui, Y., Xia, B., Gu, Z., Li, Y., Liu, F. and Cai, M. (2022). Fate, source and mass budget of sedimentary microplastics in the Bohai Sea and the Yellow Sea. Environmental Pollution, 294, pp. 118640.
  31. Naji, A., Nuri, M. and Vethaak, A.D. (2018). Microplastics contamination in molluscs from the northern part of the Persian Gulf. Environmental Pollution, 235, pp. 113–120.
  32. Claessens, M., De Meester, S., Van Landuyt, L., De Clerck, K. and Janssen, C.R. (2011). Occurrence and distribution of microplastics in marine sediments along the Belgian coast. Marine Pollution Bulletin, 62, pp. 2199–2204.
  33. Fan, S., Yan, Z., Qiao, L., Gui, F., Li, T., Yang, Q., Zhang, X. and Ren, C. (2023). Biological effects on the migration and transformation of microplastics in the marine environment. Marine Environmental Research, 185, pp. 105875.
  34. Saeed, T., Al-Jandal, N., Al-Mutairi, A. and Taqi, H. (2020). Microplastics in Kuwait marine environment: Results of first survey. Marine Pollution Bulletin, 152, pp. 110880.
  35. Karkanorachaki, K., Syranidou, E. and Kalogerakis, N. (2021). Sinking characteristics of microplastics in the marine environment. Science of the Total Environment, 793, pp. 148526.
  36. Quilliam, R.S., Jamieson, J. and Oliver, D.M. (2014). Seaweeds and plastic debris can influence the survival of faecal indicator organisms in beach environments. Marine Pollution Bulletin, 84, pp. 201–207.
  37. Chapman, P.M. (2017). Assessing and managing stressors in a changing marine environment. Marine Pollution Bulletin, 124, pp. 587–590.
  38. Adeniji, A.O., Okoh, O.O. and Okoh, A.I. (2017). Petroleum hydrocarbon profiles of water and sediment of Algoa Bay, Eastern Cape, South Africa. International Journal of Environmental Research and Public Health, 14, pp. 1263.