Assisted bioremediation tests on three natural soils contaminated with benzene

• Type: Article in International Scientific Journal
• Date: 2015

Authors

Maria Manuela Carvalho (Author) Other; Maria Cristina Vila (Author) FEUP; Cristina Delerue-Matos (Author) Other; Teresa Oliva-Teles (Author) Other; António Fiuza (Author) FEUP

Journal

Title: Eurasian Journal of Soil Science

Vol. 4 No. 3

Pages: 153-160

Publisher: Federation of Eurasian Soil Science Societies

Scientific classification

FOS: Natural sciences > Earth and related Environmental sciences

CORDIS: Natural sciences > Environmental science > Natural resources management > Environmental protection

Other information

Authenticus ID: P-00R-42X

DOI: 10.18393/ejss.2015.3.153-160

Abstract (EN): Bioremediation is an attractive and useful method of remediation of soils contaminated with petroleum hydrocarbons because it is simple to maintain, applicable in large areas, is economic and enables an effective destruction of the contaminant. Usually, the autochthone microorganisms have no ability to degrade these compounds, and otherwise, the contaminated sites have inappropriate environmental conditions for microorganism¿s development. These problems can be overcome by assisted bioremediation (bioaugmentation and/or biostimulation). In this study the assisted bioremediation capacity on the rehabilitation of three natural sub-soils (granite, limestone and schist) contaminated with benzene was evaluated. Two different types of assisted bioremediation were used: without and with ventilation (bioventing). The bioaugmentation was held by inoculating the soil with a consortium of microorganisms collected from the protection area of crude oil storage tanks in a refinery. In unventilated trials, biostimulation was accomplished by the addition of a nutrient mineral media, while in bioventing oxygen was also added. The tests were carried out at controlled temperature of 25 ºC in stainless steel columns where the moist soil contaminated with benzene (200 mg per kg of soil) occupied about 40% of the column¿s volume. The processes were daily monitored in discontinued mode. Benzene concentration in the gas phase was quantified by gas chromatography (GC-FID), oxygen and carbon dioxide concentrations were monitored by respirometry. The results revealed that the three contaminated soils were remediated using both technologies, nevertheless, the bioventing showed faster rates. With this work it was proved that respirometric analysis is an appropriate instrument for monitoring the biological activity.

Language: English

Type (Professor's evaluation): Scientific

No. of pages: 8