Hydrocarbon biodegradation in oxygen-limited sequential batch reactors by consortium from weathered, oil-contaminated soil

2005 ◽  
Vol 51 (3) ◽  
pp. 231-239 ◽  
Author(s):  
S A Medina-Moreno ◽  
S Huerta-Ochoa ◽  
M Gutiérrez-Rojas

We studied the use of sequential batch reactors under oxygen limitation to improve and maintain consortium ability to biodegrade hydrocarbons. Air-agitated tubular reactors (2.5 L) were operated for 20 sequential 21-day cycles. Maya crude oil – paraffin mixture (13 000 mg/L) was used as the sole carbon source. The reactors were inoculated with a consortium from the rhizosphere of Cyperus laxus, a native plant that grows naturally in weathered, contaminated soil. Oxygen limitation was induced in the tubular reactor by maintaining low oxygen transfer coefficients (kLa < 20.6 h–1). The extent and biodegradation rates increased significantly up to the fourth cycle, maintaining values of about 66.33% and 460 mg·L–1·d–1, respectively. Thereafter, sequential batch reactor operation exhibited a pattern with a constant general trend of biodegradation. The effect of oxygen limitation on consortium activity led to a low biomass yield and non-soluble metabolite (0.45 g SS/g hydrocarbons consumed). The average number of hydrocarbon-degrading microorganisms increased from 6.5 × 107 (cycles 1–3) to 2.2 × 108 (cycles 4–20). Five bacterial strains were identified: Achromobacter (Alcaligenes) xylosoxidans, Bacillus cereus, Bacillus subtilis, Brevibacterium luteum, and Pseudomonas pseudoalcaligenes. Asphaltene-free total petroleum hydrocarbons, extracted from a weathered, contaminated soil, were also biodegraded (97.1 mg·L–1·d–1) and mineralized (210.48 mg CO2·L–1·d–1) by the enriched consortium without inhibition. Our results indicate that sequential batch reactors under oxygen limitation can be used to produce consortia with high and constant biodegradation ability for industrial applications of bioremediation.Key words: sequential batch reactors, oxygen limitation, consortium, hydrocarbon biodegradation.

2020 ◽  
Vol 10 (12) ◽  
pp. 4173 ◽  
Author(s):  
Runkai Wang ◽  
Baichun Wu ◽  
Jin Zheng ◽  
Hongkun Chen ◽  
Pinhua Rao ◽  
...  

In this study, we isolated seven strains (termed BY1–7) from polluted soil at an oil station and evaluated their abilities to degrade total petroleum hydrocarbons (TPHs). Following 16 rRNA sequence analysis, the strains were identified as belonging to the genera Bacillus, Acinetobacter, Sphingobium, Rhodococcus, and Pseudomonas, respectively. Growth characterization studies indicated that the optimal growth conditions for the majority of the strains was at 30 °C, with a pH value of approximately 7. Under these conditions, the strains showed a high TPH removal efficiency (50%) after incubation in beef extract peptone medium for seven days. Additionally, we investigated the effect of different growth media on growth impact factors that could potentially affect the strains’ biodegradation rates. Our results suggest a potential application for these strains to facilitate the biodegradation of TPH-contaminated soil.


2019 ◽  
Vol 16 (1(Suppl.)) ◽  
pp. 0185
Author(s):  
Jabbar Et al.

This study was focused on biotreatment of soil which polluted by petroleum compounds (Diesel) which caused serious environmental problems. One of the most effective and promising ways to treat diesel-contaminated soil is bioremediation. It is a choice that offers the potential to destroy harmful pollutants using biological activity. Four bacterial strains were isolated from diesel contaminated soil samples. The isolates were identified by the Vitek 2 system, as Sphingomonas paucimobilis, Pentoae species, Staphylococcus aureus, and Enterobacter cloacae. The potential of biological surfactant production was tested using the Sigma 703D stand-alone tensiometer showed that these isolates are biological surfactant producers. The better results of the surface tension reduction test were obtained using the mixed bacterial culture which reduced the surface tension of the medium from 66mN/m to 33.89mN/m. For further evidence of the biodegradation effect of these isolates individually and as a mixed culture, which was supported by the use of Gas-Chromatography technology confirming the occurrence of biodegradation. The capability of mixed bacterial culture was examined to remediate the diesel contaminated soil in bio piles system. Two pilot scale bio piles (25 kg soil each) were constructed containing soils contaminated with approximately 2140 mg/kg total petroleum hydrocarbons (TPHs). Both systems were equipped with oxygen to provide aerobic conditions, incubated at ambient temperature and weekly sampling within 35 days (during summer season). Overall 75.71 % of the total petroleum hydrocarbons were removed from the amended soil and 33.18 % of the control soil at the end of study period. The study concluded that the ex-situ bioremediation (bio piles) is a good option for treating the soil contaminated with diesel as economical and environmentally friendly.


2019 ◽  
Vol 16 (1) ◽  
pp. 0185 ◽  
Author(s):  
Jabbar Et al.

This study was focused on biotreatment of soil which polluted by petroleum compounds (Diesel) which caused serious environmental problems. One of the most effective and promising ways to treat diesel-contaminated soil is bioremediation. It is a choice that offers the potential to destroy harmful pollutants using biological activity. Four bacterial strains were isolated from diesel contaminated soil samples. The isolates were identified by the Vitek 2 system, as Sphingomonas paucimobilis, Pentoae species, Staphylococcus aureus, and Enterobacter cloacae. The potential of biological surfactant production was tested using the Sigma 703D stand-alone tensiometer showed that these isolates are biological surfactant producers. The better results of the surface tension reduction test were obtained using the mixed bacterial culture which reduced the surface tension of the medium from 66mN/m to 33.89mN/m. For further evidence of the biodegradation effect of these isolates individually and as a mixed culture, which was supported by the use of Gas-Chromatography technology confirming the occurrence of biodegradation. The capability of mixed bacterial culture was examined to remediate the diesel contaminated soil in bio piles system. Two pilot scale bio piles (25 kg soil each) were constructed containing soils contaminated with approximately 2140 mg/kg total petroleum hydrocarbons (TPHs). Both systems were equipped with oxygen to provide aerobic conditions, incubated at ambient temperature and weekly sampling within 35 days (during summer season). Overall 75.71 % of the total petroleum hydrocarbons were removed from the amended soil and 33.18 % of the control soil at the end of study period. The study concluded that the ex-situ bioremediation (bio piles) is a good option for treating the soil contaminated with diesel as economical and environmentally friendly.


Author(s):  
V.V. Zinchenko ◽  
◽  
E.S Fedorenko ◽  
A.V Gorovtsov ◽  
T.M Minkina ◽  
...  

As a result of the model experiment, an increase in the enzymatic activity of meadow chernozem of the impact zone of Ataman Lake with the introduction of a strains mixture of metal-resistant microorganisms into the soil was established. The experiment has shown that the application of bacterial strains increases the dehydrogenase activity of contaminated soil by 51.8% compared to the variant without remediation


1986 ◽  
Vol 51 (6) ◽  
pp. 1259-1267
Author(s):  
Josef Horák ◽  
Petr Beránek

A simulation apparatus for the experimental study of the methods of control of batch reactors is devised. In this apparatus, the production of heat by an exothermic reaction is replaced by electric heating controlled by a computer in a closed loop; the reactor is cooled with an external cooler whose dynamic properties can be varied while keeping the heat exchange area constant. The effect of the cooler geometry on its dynamic properties is investigated and the effect of the cooler inertia on the stability and safety of the on-off temperature control in the unstable pseudostationary state is examined.


2021 ◽  
Vol 8 (1) ◽  
pp. 333-347
Author(s):  
Shahid Sher ◽  
Abdul Ghani ◽  
Sikandar Sultan ◽  
Abdul Rehman

Water ◽  
2021 ◽  
Vol 13 (2) ◽  
pp. 210
Author(s):  
Tang Liu ◽  
Shufeng Liu ◽  
Shishi He ◽  
Zhichao Tian ◽  
Maosheng Zheng

To explore the main behavior and mechanism of minimizing nitrous oxide (N2O) emission through intermittent aeration during wastewater treatment, two lab-scale sequencing batch reactors operated at intermittently aerated mode (SBR1), and continuously aerated mode (SBR2) were established. Compared with SBR2, the intermittently aerated SBR1 reached not only a higher total nitrogen removal efficiency (averaged 93.5%) but also a lower N2O-emission factor (0.01–0.53% of influent ammonia), in which short-cut nitrification and denitrification were promoted. Moreover, less accumulation and consumption of polyhydroxyalkanoates, a potential endogenous carbon source promoting N2O emission, were observed in SBR1. Batch experiments revealed that nitrifier denitrification was the major pathway generating N2O while heterotrophic denitrification played as a sink of N2O, and SBR1 embraced a larger N2O-mitigating capability. Finally, quantitative polymerase chain reaction results suggested that the abundant complete ammonia oxidizer (comammox) elevated in the intermittently aerated environment played a potential role in avoiding N2O generation during wastewater treatment. This work provides an in-depth insight into the utilization of proper management of intermittent aeration to control N2O emission from wastewater treatment plants.


2013 ◽  
Vol 39 (1) ◽  
pp. 83-91 ◽  
Author(s):  
Katarzyna Bernat

Abstract In this study, the dependence between volumetric exchange rate (n) in an SBR (Sequencing Batch Reactor) with a modified cycle and simultaneous nitrification and denitrification (SND) efficiency during the treatment of anaerobic sludge digester supernatant was determined. In the SBR cycle alternating three aeration phases (with limited dissolved oxygen (DO) concentration up to 0.7 mg O2/L) and two mixing phases were applied. The lengths of each aeration and mixing phases were 4 and 5.5 h, respectively. Independently of n, a total removal of ammonium was achieved. However, at n = 0.1 d-1 and n = 0.3 d-1 nitrates were the main product of nitrification, while at n = 0.5 d-1, both nitrates and nitrites occurred in the effluent. Under these operational conditions, despite low COD/N (ca. 4) ratio in the influent, denitrification in activated sludge was observed. A higher denitrification efficiency at n = 0.5 d-1 (51.3%) than at n = 0.1 d-1 (7.8%) indicated that n was a crucial factor influencing SND via nitrite and nitrate in the SBR with a low oxygen concentration in aeration phases.


2001 ◽  
Vol 43 (2) ◽  
pp. 291-295 ◽  
Author(s):  
J. Vouillamoz ◽  
M. W. Milke

The effect of compost on phytoremediation of diesel-contaminated soils was investigated using 130 small (200 g) containers in two screening tests. The experiments were conducted in a controlled environment using ryegrass from seed. Containers were destructively sampled at various times and analyzed for plant mass and total petroleum hydrocarbons. The results indicate that the presence of diesel reduces grass growth, and that compost helps reduced the impact of diesel on grass growth. The addition of compost helps increase diesel loss from the soils both with and without grass, though the addition of grass leads to lower diesel levels compared with controls. A second set of experiments indicates that the compost helps in phytoremediation of diesel-contaminated soil independent of the dilution effect that compost addition has. The results indicate that the compost addition allowed diesel loss down to 200 mg TPH/kg even though the compost would be expected to hold the diesel more tightly in the soil/compost mixture. The simplicity of the screening tests led to difficulties in controlling moisture content and germination rates. The conclusion of the research is that the tilling of compost into soils combined with grass seeding appears to be a valuable option for treating petroleum-contaminated soils.


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