Development of a bioremediation process by biostimulation of native microbial consortium through the heap leaching technique

• Published in: Journal of environmental management 2008-07, Vol.88 (1), p.115-119
• Main Authors: Salinas-Martínez, A., de los Santos-Córdova, M., Soto-Cruz, O., Delgado, E., Pérez-Andrade, H., Háuad-Marroquín, L.A., Medrano-Roldán, H.
• Format: Article
• Language: English
• Subjects: Animal, plant and microbial ecology; Applied ecology; Aspergillus; Aspergillus - metabolism; Biodegradation; Biodegradation of pollutants; Biodegradation, Environmental; Biological and medical sciences; Bioreactors; Bioremediation; biostimulation; Biotechnology; Conservation, protection and management of environment and wildlife; desorption; Diesel; diesel fuel; Environment and pollution; Environmental cleanup; Flavobacterium; Flavobacterium - metabolism; Fundamental and applied biological sciences. Psychology; General aspects; Heap leaching; heap leaching technique; hydrocarbons; Hydrocarbons - chemistry; Hydrocarbons - metabolism; Indicator organisms; Industrial applications and implications. Economical aspects; Leaching; methodology; Microbial consortium; microbial ecology; mined soils; minerals; Mining; new methods; petroleum; sand; Soil contamination; soil microorganisms; Soil Pollutants - chemistry; Soil Pollutants - metabolism; soil pollution; solutions; Time Factors
• ISSN: 0301-4797; 1095-8630
• DOI: 10.1016/j.jenvman.2007.01.038

Heap leaching is an effective and widely used method of recovering metals from low-grade ores. However, the heap leaching technique has not yet been used in other biotechnological processes such as bioremediation. This work describes biostimulation of the native microbial consortium as a novel application of the heap leaching technique to bioremediate mining soils contaminated with hydrocarbons. Microorganisms present in the polluted soil were isolated in a liquid mineral solution using diesel fuel as the sole energy and carbon source. Biodegradation activity was evaluated and two genera, Flavobacterium and Aspergillus, were identified as the primary microorganisms that degraded hydrocarbons in the polluted soil. In order to simulate the heap leaching process on a laboratory scale, using both columns and piles, the contaminated soil was mixed with different sand concentrations and was agglomerated before it was used. Three flow rates, of the mineral solution, were evaluated. Of the rates tested, biodegradation was most efficient at a flow rate of 200 ml h −1. The heap leaching technique demonstrated good efficiency in the column and pile, with a 2% soil–sand mixture lowering the TPH concentration from 61,000 to 1800 mg kg −1 (98.5%) in 15 d.