Fast start-up of anammox process: Effects of extracellular polymeric substances addition on performance, granule properties, and bacterial community structure. (15th July 2023)

• Record Type: Journal Article
• Authors: Yang, Dongmin; Zuo, Jialiang; Jiang, Cancan; Wang, Danhua; Gu, Likun; Zhang, Shujun; Lu, Huijie; Wang, Dongsheng; Xu, Shengjun; Bai, Zhihui; Zhuang, Xuliang
• Is Part Of: Journal of environmental management. Volume 338(2023)
• Publication Date: 2023-07-15
• Subjects: Extracellular polymeric substances -- Calcium alginate -- Anammox bacteria; Environmental policy -- Periodicals; Environmental management -- Periodicals; Environment -- Periodicals; Ecology -- Periodicals; 363.705
• DOI: 10.1016/j.jenvman.2023.117836
• Languages: English
• ISSNs: 0301-4797

Abstract

Abstract: The slow startup is the major obstacle to the application of anaerobic ammonium oxidation (anammox) process in mainstream wastewater treatment. Extracellular polymeric substances (EPS) are one potential resource for stable anammox reactor operation. Response surface analysis was used to optimize the specific anammox activity (SAA) with the addition of EPS; SAA was maximum at a temperature of 35 °C and the EPS concentration of 4 mg/L. By comparing the nitrogen removal of anammox reactors with no EPS (R0), immobilized EPS (EPS-alginate beads) (R1), and liquid EPS (R2), we found that EPS-alginate beads significantly speed up the startup of anammox process and enable the start time to be shortened from 31 to 19 days. As a result of the higher MLVSS content, higher zeta potential, and lower SVI30, anammox granules of R1 exhibited a stronger capacity to aggregate. Moreover, EPS extracted from R1 had higher flocculation efficiencies than EPS derived from R0 and R2. Phylogenetic analysis of 16S rRNA genes revealed that the main anammox species in R1 is Kuenenia taxon. To clarify the relative significance of stochastic vs deterministic processes in the anammox community, neutral model and network analysis are employed. In R1, community assembly became more deterministic and stable than in other cultures. Our results show that EPS might inhibit heterotrophic denitrification and thereby promote anammox activity. This study suggested a quick start-up strategy for the anammox process based on resource recovery, which is helpful for environmentally sustainable and energy-efficient wastewater treatment. Highlights: The start-up time of anammox process was shortened by 38.7% in R1. R1 could maintain stable operation at NLR from 229.53 to 936.37 mgN L −1 d −1 . EPS-alginate beads improved the properties of anammox granules. The role of stochastic processes on community assembly process was lower in R1. There were higher negative correlations of microbial network in R1.