Evaluating the roles of zero valent iron on the metagenome during thermophilic anaerobic digestion of sludge

To reduce the knowledge gaps, metagenomic approach has been used to provide a full profile in WAS before and after the TAD treatment with mZVI.Four batch experimental groups spiked with mZVI of 0, 25, 100, and 250 mg/g TS were carried out for anaerobic digestion, and each group was parallel, marked as Z1, Z2, Z3 and Z0, respectively. All reactors were firstly loaded with 200 mL of WAS in 250 mL serum bottles, then flushed with high-purity nitrogen for 2 min and sealed with rubber stoppers, and incubated at thermophilic in the water bath. The whole operation period lasted for 32 d. Samples collected at the endwere centrifuged at 8,000 rpm for 10 min to obtain sludge samples for metagenomic analysis.