Browsing by Author "Sartaj, Majid"

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    Biodegradation of heavy oily sludge by a two-step inoculation composting process using synergistic effect of indigenous isolated bacteria
    (Elsevier, 2019-12-24) Parhamfar, Maryam; Abtahi, Hamid; Godini, Kazem; Saeedi, Reza; Sartaj, Majid; Villaseñor, José; Coulon, Frederic; Kumar, Vinod; Soltanighias, Tayebeh; Ghaznavi-Rad, Ehsanollah; Koolivand, Ali
    The impact of two-step inoculation of indigenous strains and their synergistic effect in the scaling-up of petroleum hydrocarbons biodegradation from a mineral-based medium (MBM) to a two-phase composting process were investigated. After isolating the strains KA3 and KA4 from heavy oily sludge (HOS), their emulsification index (E24), bacterial adhesion to hydrocarbon (BATH), and oil degradation efficiency were evaluated in the MBM. Then, they were inoculated twice into the composting bioreactors lasted for the primary 8 weeks as the first phase (FP) and subsequent 8 weeks as the second phase (SP). The results indicated that the consortium of the two strains degraded 16-61% of crude oil (1-5% concentration) in the MBM. In the composting reactors, removals of 20 g kg−1 initial concentration of total petroleum hydrocarbons (TPH) were found to be 63.95, 61.00, and 89.35% for the strains KA3, KA4, and their consortium, respectively. The computed biodegradation constants indicated the synergistic effect of the two strains and the effectiveness of the second-step inoculation. The study demonstrated the successful scaling-up of HOS biodegradation from MBM to the two-phase composting process through two-step inoculation of the isolated strains.
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    Biodegradation of oily waste sludge using vermiremediation and composting process bioaugmentated with isolated hydrocarbon-degrading bacteria: performance and ecotoxicity assessment
    (Elsevier, 2024-12-01) Alinoori, Maral; Saeedi, Reza; Coulon, Frederic; Villaseñor, José; Goodini, Kazem; Ghamari, Farhad; Hesampoor, Faezeh; Asghari, Fatemeh; Sartaj, Majid; Koolivand, Ali
    Degradation of petroleum hydrocarbons (PHs) contents of oily waste sludge (OWS) is necessary in order to prevent the related environmental pollution. The present study aimed to investigate the degradation of total petroleum hydrocarbons (TPHs) from OWS using bioaugmentated composting (BC) with hydrocarbon-degrading bacterial consortium (HDBC) as pre-treatment followed by vermicomposting (VC) by Eisenia fetida. After isolating two indigenous bacterial strains from OWS, the ability of their consortium in degradation of crude oil was tested in Bushnell-Haas medium (BHM). Then, biodegradation of OWS was measured in the VC alone, BC alone, simultaneous BC and VC (BCVC), and BC followed by VC (BCFVC) containing high levels (30 g/kg) of TPHs. Toxicity tests including the mortality of mature earthworms and the numbers of juveniles were conducted at the TPHs of 0–40 g/kg. The obtained results indicated that the HDBC removed 18–64 % of TPHs of crude oil (1–5 %) in BHM after 7 days of incubation. After a period of 12 weeks, the removal rates of TPHs in the VC, BC, BCVC, and BCFVC experiments were 23.7, 79.5, 85.2, and 91.8 %, respectively, verifying the efficacy of simultaneous application of HDBC and worms in bioremediation of OWS. The TPHs contents of OWS exhibited toxic effects on E. fetida at some concentrations and the median lethal concentration (LC50) of TPHs was computed to be 14.5 g/kg after 28 days. This study demonstrated the effectiveness of composting bioaugmentated with HDBC as a pre-treatment step followed by vermicomposting in bioremediation of OWS.
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    Effect of competition between petroleum-degrading bacteria and indigenous compost microorganisms on the efficiency of petroleum sludge bioremediation: field application of mineral-based culture in the composting process
    (Elsevier, 2020-01-06) Abtahi, Hamid; Parhamfar, Milad; Saeedi, Reza; Villaseñor, José; Sartaj, Majid; Kumar, Vinod; Coulon, Frederic; Parhamfar, Maryam; Didehdar, Mojtaba; Seifi, Hamed; Koolivand, Ali
    The effect of competition between isolated petroleum-degrading bacteria (PDB) and indigenous compost microorganisms (ICM) on the efficiency of composting process in bioremediation of petroleum waste sludge (PWS) was investigated. After isolating two native PDB (Acinetobacter radioresistens strain KA5 and Enterobacter hormaechei strain KA6) from PWS, their ability for growth and crude oil degradation was examined in the mineral-based culture (MBC). Then, the PDB isolate were inoculated into the composting experiments and operated for 12 weeks. The results showed that the PDB degraded 21.65–68.73% of crude oil (1–5%) in the MBC after 7 days. The PDB removed 84.30% of total petroleum hydrocarbon (TPHs) in the composting bioreactor containing the initial TPH level of 20 g kg−1. Removal of petroleum hydrocarbons (PHCs) in the composting experiments proceeded according to the first-order kinetics. The computed values of degradation rate constants and half-lives showed a better performance of the PDB than ICM for TPHs removal. This finding suggests that simultaneous application of the PDB and ICM in the composting reactors resulted in a decline in the effectiveness of the PDB which is due to competition between them. The study also verified that the capability of PDB in degrading PHCs can be successfully scaled-up from MBC to composting process.
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    The effect of petroleum hydrocarbons concentration on competition between oil-degrading bacteria and indigenous compost microorganisms in petroleum sludge bioremediation
    (Elsevier, 2022-01-17) Koolivand, Ali; Abtahi, Hamid; Parhamfar, Maryam; Saeedi, Reza; Coulon, Frederic; Kumar, Vinod; Villaseñor, José; Sartaj, Majid; Najarian, Niloofar; Shahsavari, Maedeh; Seyedmoradi, Paria; Rahimi, Leila; Bagheri, Fatemeh
    The influence of the concentration of total petroleum hydrocarbons (TPHs) on competition between isolated oil-degrading bacteria (ODB) and finished compost microorganisms (FCM) was investigated in composting bioreactors over 12 weeks period. First, the batch tests were performed in Bushnell–Haas medium (BHM) to evaluate the biodegradation activities of six native ODB isolated from petroleum sludge (PS). Then, the ODB were added to the composting bioreactors containing 10 and 30 g/kg of TPHs. Based on the BHM results, the highest degradation efficiency of crude oil (1%–3% concentration) were determined to be 72%–75% at pH 7 after 7 days. In the composting bioreactors containing only the ODB, TPHs removal rates were 86%–92% after 12 weeks. Although the lower degradation efficiency of TPHs (73%–89%) in the bioreactors containing both the FCM and ODB indicated a slight competition between them, the ODB were still effective in the presence of the FCM especially at greater concentrations of TPHs. Despite the fact that the addition of finished compost (FC) to the PS changed the microbial composition in the composting bioreactors; the microbial populations exhibited little variation during the process. This study indicated that the isolated ODB, alone or in the presence of the FCM, effectively degraded the PS in the composting process.