Impact of phytoremediation and bioaugmentation on microbial community in oil shale chemical industry solid waste

Abstract

Field and laboratory experiments were carried out in order to estimate the suitability ofphytoremediation and bioaugmentation for oil shale chemical industry solid waste (semicoke) dump area remediation as well as influence of plants and laboratory selecteddegradative bacterial strains on the microbial communities in semi-coke, Field test plots (each50 m2) were established at semi-coke depository in July 200 I and samples for microbiologicaland chemical analysis were collected in October 2002 and 2003, Microbial communities insemi-coke were · analysed using both culture-based and molecular methods, Changes inmicrobial community structure and activity occurred in semi-coke as a result ofphytoremediation and bioaugmentation, Phytoremediation increased the number of oildegrading bacteria and diversity of microbial community in semi-coke as well as microbialbiomass. A comparison of 16S rRNA gene-based DGGE fingerprints of semi-coke samplesusing multivariate analysis showed variation between the bacterial community profiles fromdifferent treatments. Degradation rates of pollutants did not differ significantly between plotswith vegetation except for sod, showing negligible effect of soil amendment typeonbiodegradation activity. Our results indicate that increased biodegradation activity was due toproliferation of specific microbial groups, changes in taxonomic and metabolic diversity ofbacterial community and shifts in the structure of catabolic genes, Based on our findings weconclude that phytoremediation and bioaugmentation could be considered as an alternativemanagement option for remediation of oil shale solid waste.