Low strength wastewater anammox start-up and stable operation by inoculating sponge-iron sludge: Cooperation of biological iron and iron bacteria

Rapid Start-Up and Long-Term Stability of Anammox with Magnetic Biochar Addition: Performance Improvement, Microbial Community, and Potential Mechanisms

“…The average reduction of NO 2 – –N for each reactor during this period was CS700 (92.4%), FCS500 (90.9%), FCS300 (83.6%), FCS700 (72.4%), CS500 (71.4%), CS300 (70.9%), and CK (64.6%). Earlier, AnAOB barely produced NO 3 – –N, while NO 2 – –N was removed in large quantities, suggesting that denitrifying bacteria may dominate . AnAOB has a far poorer adaption to the culture environment than denitrifying bacteria, and they grow at a lower rate with longer multiplication times of 15–30 days .…”

“…Arcanely, OM190, which frequently coexists with macroalgae, was a possible cellulose degrader appropriate for starvation and played a larger role in anammox start-up at low NRL. 16 In contrast, magnetic biochar led to an average of 35.1% higher number of edges than the CK group and a substantially higher positive correlation and average weighted degree than CK. Furthermore, the proportion of positive and negative correlations changed significantly, and magnetic biochar improved the synergistic survival of microorganisms.…”

“…The start-up phase can be separated into three steps based on the concentration of NH 4 + –N in influent and effluent: (I) the bacterial hydrolysis period (effluent NH 4 + –N higher than influent); (II) the activity improvement (effluent NH 4 + –N gradually decreased, effluent NO 2 – –N gradually increased and then decreased); (III) the stable operation period (synergistic removal of NH 4 + –N and NO 2 – –N in proportion to each other). Several researchers also described the distinct steps of the start-up process. , …”

“…Earlier, AnAOB barely produced NO 3 − −N, while NO 2 − −N was removed in large quantities, suggesting that denitrifying bacteria may dominate. 16 AnAOB has a far poorer adaption to the culture environment than denitrifying bacteria, and they grow at a lower rate with longer multiplication times of 15−30 days. 2 The individual reactor durations in this phase were FCS700 for 4 days, FCS300, CS300, and CS500 for 5 days, CS700 for 6 days, FCS500 for 7 days, and CK for 10 days.…”

“…Several researchers also described the distinct steps of the start-up process. 4,16 In the bacterial hydrolysis period, organic nitrogen release by microbial dissolution resulted in effluent NH 4 + −N being higher than the influent. Meanwhile, the organic matter produced by bacterial hydrolysis was used as a carbon source by heterotrophic denitrifying bacteria, leading to the continuous removal of NO 2 − −N during this period.…”