Impact of compost amendments and operating temperature on diesel fuel bioremediation

Abstract

A laboratory study was conducted to investigate the performance of composting bioremediation of a sand material contaminated with diesel fuel and radio-labeled phenanthrene. The material was amended with either fresh feedstock material or finished compost and then incubated at either thermophilic or mesophilic temperatures for 126 d. In controls that were not amended with compost, no mineralization of 14C phenanthrene was detected, whereas treatments that received compost amendments had significant phenanthrene mineralization, ranging from 25% to 42% of initial concentrations. The lowest extractable diesel range organic residual (1092 mg kg–1 total solids) was observed in the treatment receiving fresh compost amendment and incubated at thermophilic temperatures, whereas the highest residual (8507 mg kg–1 total solids) was observed in the control without any amendment. Whereas all the treatments that received amendment dramatically outperformed the control reactors, significant differences were observed among the treatment performances. This suggests that amendment type and operating temperature were important factors impacting bioremediation performance. Key words: compost amendments, bioremediation, diesel fuel, phenanthrene, temperature.