Adriana Criste

Lab-scale experimental investigation concerning ex-situ bioremediation of petroleum hydrocarbons-contaminated soils

ABSTRACT The bioremediation of petroleum hydrocarbons (PHCs)-polluted soils was studied by an ex-situ, lab-scale, biopile experiment with different parameters: aeration rate (1 h day−1 and 2 h day−1), soil moisture (44% and 60%), and microorganisms consortia addition (320 and 640 mL). The trial was conducted using eight treatment cells, each having different parameters, and one control cell for 18 weeks on soil containing 7600 ± 400 mg kg−1 total PHCs, taken from a former petroleum product warehouse in Sfantu Gheorghe, Covasna County (Romania). The microorganisms used for bioremediation were isolated from the native microflora of the polluted soil and grown in laboratory on culture media. A bioremediation yield up to 76% was obtained in the test cells, while in the control cell the reduction of PHCs content by 16% was attributed to natural attenuation. The results indicated that by addition of microorganisms the bioremediation is much more effective than natural attenuation. The results also revealed an accentuated decrease in PHC concentrations after 4 weeks of treatment, irrespective of the treatment conditions.