Influence of nutrient level on biodegradation and bioconcentration of phthalate acid esters in Chlorellavulgaris

Abstract

Influences of major nutrients (N, P) on the biodegradation and bioconcentration of dibutyl phthalate (DBP) and di-2-ethylexyl phthalate (DEHP) by Chlorella vulgaris in lake water were investigated in this work. Our study demonstrated that nutrient addition obviously influenced biodegradation rate constants and apparent bioconcentration factors (BCFs) of DBP and DEHP in Chlorella vulgaris. The effects of P addition on biodegradation were less pronounced than the effects of N addition as a result of N-limitation status of phytoplankton in the lake water, while addition of both N and P more greatly affected biodegradation than addition of N or P. BCFs of DBP and DEHP decreased with increasing algal exudate as measured by dissolved organic carbon (DOC) and a strong correlation between BCFs and DOC was obtained. The results indicate that DOC plays an important role in the bioconcentration of DBP and DEHP.

Keywords:

• Biodegradation
• bioconcentration
• dibutyl phthalate
• di-2-ethylexyl phthalate
• nutrient level
• Chlorella vulgaris

Acknowledgments

This work was supported by the National Natural Sciences Foundation of China (Contract/grant number: 20277026).