BIOREMEDIATION OF CEMENT AND OIL CONTAMINATED SOIL IN CONSTRUCTION SITES USING COMBINED TECHNIQUES: A CASE STUDY IN IRAN

This paper studies the bioremediation techniques utilized to degradation of soil pollutants of aconstruction site in Iran. The activities in the construction site, located in Garmdareh, Karaj, polluted thesoil environment with a large number of contaminants most importantly BTEX, PAHs and heavy metals.Remediation of the soil polluted with this components based on conventional physicochemical techniquesis both technically and economically challenging. Bioremediation that involves the capabilities ofmicroorganisms in the removal of pollutants is the most promising, relatively efficient and cost-effectivetechnology. In this study, a coupled bioventing-biosparging technique and the phytoextraction processwere used to remediate the deep layers and shallow layers of polluted soil respectively. However,widespread presence of the cement components in the site influenced the performance of bioremediationtechniques. The results indicated that the cement-polluted soil lowered the degradation rate of both BTEX(Ethylbenzene) and PAH (Pyrene) pollutants when deep layers were concerned. Conversely, regardingphytoextraction, the degradation rate of Pb was increased in phytoextraction process due to properstabilization of surficial soil in presence of cement components. This study provides a critical view on thelimitations and influential parameters of function-directed soil remediation techniques dealing with thepresence of cementitious material in the construction sites