The effects of carbon sources and micronutrients in whey and fermented whey on the kinetics of phenanthrene biodegradation in diesel contaminated soil

Abstract

This paper demonstrates significant effects on phenanthrene degradation in diesel contaminated soil by the addition of organic amendments such as whey and fermented whey. Both amount of amendment added and mode of administration was shown to be decisive. There was a strong positive effect on the (14)C-mineralization of phenanthrene by multiple (bi-weekly) additions of fermented whey 210 mg dw kg(-1) soil dw (FW multi) and also by single dose addition of 2100 mg dw sweet whey kg(-1) soil dw (SW high). The most prominent effects on phenanthrene degradation kinetics were a five to fifteen fold increase in the linear growth term (k(2)) and a 23-27% increase in bioavailability factor S(0) for SW high and FW multi respectively. Also, total mineralization at the end of the experiment increased from 46% in the control to 66 and 71% respectively and the lag time was reduced from 21 to 15 days by multiple addition of fermented whey. The most significant stimulating effects on phenanthrene degradation kinetics could be attributed to lactate and vitamins. This study demonstrates a more complex dependence of carbon sources and growth factors for an aromatic compound such as phenanthrene in comparison to hexadecane.