17 beta-estradiol biodegradation by anaerobic granular sludge: Effect of iron sources

Bai-Hang Zhao,Bao-Jiang Liu,Jie Chen,Xin-Yue Zhang,Qi Sun,Jun Li,Jing Zhang

doi:10.1038/s41598-020-64557-5

Abstract

Steroid estrogens, as typical endocrine disrupting chemicals (EDCs), have raised an increasing concern due to their endocrine disrupting effects on aquatic animals and potential hazards on human health. Batch experiments were conducted to study 17 beta-estradiol (E2) removal and Estradiol Equivalent Quantity (EEQ) elimination by anaerobic granular sludge (AnGS) combined with different valence iron sources. Results showed that E2 was effectively biodegraded and transformed into E1 by AnGS. The addition of different valence iron sources all promoted E2 degradation, reduced E2 Equivalent Quotient (EEQ) concentration, and increased methane production in the batch experiments. The enhancement effect of zero-valent iron (ZVI) on E2 removal and EEQ elimination was stronger than that of Fe2+ and Fe3+ in our experiments. The enhancement effect proportion of ZVI corrosion, Fe2+, and Fe3+ in the process of E2 degradation by AnGS combined with ZVI were 42.26%, 40.21% and 17.53%, respectively.

Highlights

Steroid estrogens, as typical endocrine disrupting chemicals (EDCs), have raised an increasing concern due to their endocrine disrupting effects on aquatic animals and potential hazards on human health
The blue region, green region and red region represent E2 dissolved in the water phase, E2 biodegraded by anaerobic biotransformation and E2 adsorbed by anaerobic granular sludge (AnGS), respectively
A high E2 biodegradation efficiency of 82.17% was gotten after 4.5 days in our AnGS system, which was comparable to the report of Alvarino et al Ling et al.[31] analyzed the microorganisms for E1, E2, E3, and EE2 degradation, and found that 57% of microorganisms were Proteobacteria

Summary

Introduction

As typical endocrine disrupting chemicals (EDCs), have raised an increasing concern due to their endocrine disrupting effects on aquatic animals and potential hazards on human health. Batch experiments were conducted to study 17 beta-estradiol (E2) removal and Estradiol Equivalent Quantity (EEQ) elimination by anaerobic granular sludge (AnGS) combined with different valence iron sources. Czajka et al.[20] observed that E2 could be transformed to E1 under different circumstances of methanogenic, sulfate-, iron-, or nitrate-reducing conditions, but the EEQ concentration was almost nothing changed at the different conditions This suggests that considering EEQ elimination is more important than that of a certain estrogen substance removal because of the health hazard of estrogenic potency to human and aquatic organisms. It has been reported that the exiting of some actives substances, such as dissolved organic matter or Fe3+, could enhance estrogen biodegradation by anaerobic microorganisms[21]. The effects of ZVI, Fe2+ and Fe3+ on E2 degradation, EEQ elimination, and methane production were investigated here, with the degradation kinetic

Methods

Results

Conclusion