Advanced nitrogen removal from landfill leachate via Anammox system based on Sequencing Biofilm Batch Reactor (SBBR): Effective protection of biofilm

• Published in: Bioresource technology 2016-11, Vol.220, p.8-16
• Main Authors: Miao, Lei, Wang, Shuying, Cao, Tianhao, Peng, Yongzhen, Zhang, Man, Liu, Zhaoyuan
• Format: Article
• Language: English
• Subjects: Anammox; Bacteria - genetics; Bacteria - metabolism; Biofilm; Biofilms; Biological Oxygen Demand Analysis; Bioreactors - microbiology; Denitrification; EPS; Equipment Design; Flocculation; Heterotrophic Processes; Landfill leachate; Microbial Consortia - genetics; Microbial Consortia - physiology; Nitrogen - chemistry; Nitrogen - isolation & purification; PCR; Waste Disposal, Fluid - instrumentation; Waste Disposal, Fluid - methods; Water Pollutants, Chemical - chemistry; Water Pollutants, Chemical - metabolism
• ISSN: 0960-8524; 1873-2976
• DOI: 10.1016/j.biortech.2016.06.131

[Display omitted] •Anammox was enriched in carriers to enhance ability against adverse environment.•As influent TN was 3000mg/L, effluent TN was below 20mg/L with TN removal of 95%.•The ratio of NO3−:NH4+ fell below 0.1 in Anammox process treating real leachate.•TB-EPS of biofilm and floccule were 46% and 28%, respectively, helped form biofilm.•Anammox gene ratio of biofilm increased to 13.28%, yet floccule decreased to 3.88%. High levels of organics negatively affect Anammox for treating landfill leachate. To enhance the ability of Anammox to survive against adverse environments, a lab-scale two-stage Anammox system using a Sequencing Biofilm Batch Reactor was applied to treat mature landfill leachate under 35°C. Over 107days, with influent total nitrogen (TN) and chemical oxygen demand (COD) concentrations of 3000±100 and 3000±100mg/L, effluent TN was below 20mg/L. For extracellular polymeric substance (EPS) of Anammox, slime-EPS and loosely-bound-EPS of floccules were both higher than biofilm, while tight-bound-EPS of biofilm was significantly higher, contributing to biofilm formation. Quantitative microbial analysis showed that as influent COD increased, Anammox gene ratios of biofilm increased from 1.34% to 13.28%; the gene ratios of floccule first increased, then decreased to 3.88%. This indicated that Anammox and heterotrophic bacteria could coexist because of the biofilm, leading to stable nitrogen removal performance, even when organics were present.