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Updated: Jul 21, 2026

A Novel Bioreactor for High Density Cultivation of Diverse Microbial Communities
Published on: December 25, 2015
Responses of suspended sludge and biofilm in a SNAD system under C/N elevation: Microbial activity, nitrogen
Junyu Liu1, Meina Hu1, Mei Hu1
1Beijing Engineering Research Center of Environmental Material for Water Purification, College of Chemical Engineering, Beijing University of Chemical Technology, Beijing 100029, China.
Abstract:
The simultaneous partial nitrification, anammox and denitrification (SNAD) process had received widespread attention as an advanced wastewater treatment process. In this study, the SNAD mainstream nitrogen removal process with the incorporation of polyurethane sponge packing under different C/N conditions was investigated. Results showed that the highest nitrogen removal efficiency of the system was achieved at the C/N of 2.0, while the high C/N (3.5) significantly deteriorate the nitrogen removal efficiency. Meanwhile, high C/N (3.5) significantly inhibited the activity and abundance of anammox bacteria (mainly Candidatus_Kuenenia), resulting in the decreased contribution of anammox (from 63.14 % to 48.09 %). The significant divergence of microbial interactions in the suspended sludge and biofilm was observed with increasing C/N. Compared with suspended sludge, biofilm facilitated higher abundance and activity of anammox bacteria, and the molecular ecological network of biofilm displayed better stability and more efficient mass transfer efficiency between microorganisms. The C/N of 3.5 simplified the subnetworks of Chloroflexi and Proteobacteria but increased the positive interactions between Planctomycetota and other microbes. Anammox bacteria were found as keystone species only in biofilm system. This study provided a theoretical basis and technical guidance for the application of SNAD process in municipal wastewater treatment.
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