Bacterial Communities in Effluents Rich in Phenol and Their Potential in Bioremediation: Kinetic Modeling

Int J Environ Res Public Health. 2022 Oct 31;19(21):14222. doi: 10.3390/ijerph192114222.

Abstract

Phenol is used in the manufacturing process of phenolic resins from which residues remain that must be sent for confinement. For that reason, in this study, the wastewater of a resin factory was analyzed to isolate the bacteria present, identify them by molecular methods and finally evaluate their impact on bioremediation treatment. A total of 15 bacteria were isolated, of these, eight belong to the genus Bacillus spp. All bacteria were individually multiplied and inoculated in clusters in 15 L reactors which were carefully monitored for pH, electrical conductivity, chemical oxygen demand and temperature. The acquired data were analyzed using ANOVA with repeated measurements. The first test revealed that native bacterial communities reduce the phenol content by up to 20% and COD by 49%, which is significant with respect to the reactor not being inoculated with bacteria. Furthermore, when a mathematical model was applied to the reactors, it was shown that the bacteria require an adaptation time of approximately 100 h. A second test where the inoculation was interspersed with the addition of lime as a flocculant showed that, even though the reduction in phenol and COD was lower than in the previous test, the difference between treatments and control is statistically significant (α ≤ 0.05).

Keywords: COD; bacterial growth; molecular identification; native bacteria; phenolic waste.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Bacteria
  • Biodegradation, Environmental
  • Bioreactors / microbiology
  • Phenol* / chemistry
  • Phenols
  • Waste Disposal, Fluid / methods
  • Wastewater* / microbiology

Substances

  • Phenol
  • Waste Water
  • Phenols

Grants and funding

The research was internally financed by Instituto Politécnico Nacional (SIP projects: 20210507 and 20211172). The first author is grateful to the Consejo Nacional de Ciencia y Tecnología (CONACyT) through the doctorate scholarship granted to her.