A critical review on trace elements and bioavailability in anaerobic digestion system

The effects of trace elements on anaerobic digestion system were reviewed in this paper. On one hand, the composition of trace element in different fermented raw materials, the relationship between trace elements and enzymes, the effects of trace elements on the performance of the digestion system and microbial community succession were summarized. On the other hand, the application of sequential extraction method, the relationship between the chemical fraction and bioavailability, the factors affecting the bioavailability (ligands and pH), and the strategies for stabilizing bioavailability were introduced. This review would provide guidance for efficient and stable operation of biogas project.