Treatability test of PAHs in marine sediment

Abstract

To evaluate the bioremedial treatmentes for sediments contaminated with PAHs, the effects of oxygen supplied with H2O2, substitutional electron acceptor such as calcium nitrate, organic materials such as yeast extract, solubilizing enhancer such as 2-hydroxypropyl-β-cyclodextrin and PAHs degrading bacteria on PAHs biodegradation were studied using sediment slurry spiked with 100 ppm of pyrene. We used two different sediment samples showing different characteristics; the one collected from st. SM was relatively aerobic and contained lower biomass, the other from st. WS was anaerobic and contained higher biomass. The evolution rate of CO2 increased by all kinds of treatment. The addition of trace organic material was most effective for the sample from st. SM and aeration was most effective for st. WS. From the experiment using 14C-phenanthrene and 14C-pyrene as substrates, it was evident that the aeration enhanced the mineralization rate of high molecular weight PAHs. The results in the present study imply that 1) bioremedial treatments enhance the removal rate of toxic organic pollutants and 2) appropriate treatment should be selected through treatability test because the limiting factor for biodegradation of contaminant might be site specific. [This research was supported by Ministry of Environment in Korea and KORDI.]