phytoremediation of phenanthrene from soil by sorghum

investigations around some oil and gas refineries showed that phenanthrene is the predominant form of pahs in these areas. so, in this study, the role of sorghum vulgare pers. sudanense (a warm season grass type) in removal of phenanthrene from soils (phytoremediation) in a 16 week period greenhouse study is investigated. the stress of phenanthrene presence on plant's physiological activity, such as chlorophyll content and biomass was studied. to assess ecological risk of the method, pollutant accumulation in plant tissue was determined. all determinations were performed by hplc and statistical analysis, t-test and tukey, was done by spss program. results showed that in planted treatments there was a 20% increase in pollutant removal comparing with unplanted treatments. furthermore, it was shown that the most of the phenanthrene was degraded in the rhizosphere region and it didn't migrate toward upper parts of plant. also, it was shown that phenanthrene didn't affect plants physiological activities.all results was verified statistically in 95% significance level (p