Resumen

DIAZ-BORREGO, Laugeny Chiquinquirá et al. AUTOCHTHONOUS MICROBIAL CONSORTIUM FOR DIESEL CONTAMINATED WATER TREATMENT FROM TOAS ISLAND HARBOR (VENEZUELA). Cienc. Ing. Neogranad. [online]. 2018, vol.28, n.2, pp.5-27. ISSN 0124-8170.  https://doi.org/10.18359/rcin.2792.

The biological treatment of polluted water using autochthonous microbial consortia harnesses the metabolic potential of different groups of microorganisms to degrade and/or remove a wide variety of compounds. Additionally, biostimulation and bioaugmentation techniques contribute to enhancing the capabilities of these biodegradation processes. The objective of this paper was to evaluate the use of an autochthonous microbial consortium (Chlorella spp.-bacteria) to treat water at the Toas Island harbor (Maracaibo Lake, Venezuela), polluted by 1 % v/v diesel. For this, two treatments (T1: biostimulated and T2: bioaugmented) and a control were used for 70 days, at a scale of 20 L and under controlled environmental conditions. During the tests, temperature, pH, chemical oxygen demand (COD), nitrite, nitrate, total Kjeldahl nitrogen, total nitrogen (TN), orthophosphate, total phosphorus (TP), total petroleum hydrocarbons (TPH), hydrocarbon fractions (SARA), microalgal and bacterial density, and photosynthetic pigments were monitored, according to standardized methods. The mean values for organic matter removal (COD), TN and TP were 23.3 ± 2.3, 35.2 ± 4.5 and 64.6 ± 4.8 % for control; 27.6 ± 1.64, 79.8 ± 2.05 and 87.7 ± 1.95 % for T1 ; and <0.1; 16.1 ± 0.38 and 44.7 ± 1.18% for T2. The final concentrations of TPH were above the permissible limit of Venezuelan regulations for discharges into natural bodies of water; however, high rates of saturated and aromatic hydrocarbon removal (>70 %) were obtained, particularly in the bioaugmented treatment (T2). Autochthonous microbial consortia have great potential for the biorecovery of water at the Toas Island harbor, polluted by petroleum hydrocarbons. Therefore, it is advisable to continue researching into this treatment technology.

Palabras clave : bioaugmentation; biological treatment; biostimulation; hydrocarbons; microbial degradation; mixotrophic metabolism.

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