Comparison of the effects of salinity on microbial community structures and functions in sequencing batch reactors with
- PDF / 1,825,067 Bytes
- 14 Pages / 595.276 x 790.866 pts Page_size
- 16 Downloads / 177 Views
RESEARCH PAPER
Comparison of the effects of salinity on microbial community structures and functions in sequencing batch reactors with and without carriers Ting Li1 · Zixuan Guo1 · Zonglian She1,2 · Yangguo Zhao1,2 · Liang Guo1,2 · Mengchun Gao1,2 · Chunji Jin1,2 · Junyuan Ji1,2 Received: 5 April 2020 / Accepted: 3 July 2020 © Springer-Verlag GmbH Germany, part of Springer Nature 2020
Abstract This study investigated and compared the microbial communities between a sequencing batch reactor (SBR) without carriers and a hybrid SBR with addition of carriers for the treatment of saline wastewater. The two systems were operated over 292 days with alternating aerobic/anoxic mode (temperature: 28℃, salinity: 0.0–3.0%). High removal efficiency of chemical oxygen demand (COD) and total inorganic nitrogen (TIN) was achieved in both the SBR (above 86.7 and 95.4% respectively) and hybrid SBR (above 84.4 and 94.0%) at 0.0–2.5% salinity. Further increasing salinity to 3.0% decreased TIN removal efficiency to 78.4% in the hybrid SBR. Steep decline of biodiversity and relative abundance of ammonia-oxidizing bacteria (AOB) contributed to the worse performance. More genera related to sulfide-oxidizing and sulfate-reducing bacteria were detected in the hybrid SBR than the SBR at 3.0% salinity. The abundance of halotolerant bacteria increased with the salinity increase for both reactors, summing up to 25.5% in the suspended sludge (S-sludge) from the SBR, 28.9 and 22.9% in the S-sludge and biofilm taken from the hybrid SBR, respectively. Nitrification and denitrification via nitrate was the main nitrogen removal pathway in the SBR and hybrid SBR at 0.0 and 0.5% salinity, while partial nitrification and denitrification via nitrite became the key process for nitrogen removal in the two reactors when the salinity was increased to 1.0–3.0%. Higher abundance of anaerobic ammonium-oxidizing (ANAMMOX) and sulfide-oxidizing autotrophic denitrification (SOAD) bacteria were found in the hybrid SBR at 3.0% salinity. Keywords SBR · Hybrid SBR · Bacterial community functions · Carrier · Salinity · Biofilm
Introduction Suspended sludge (S-sludge) and biofilms based on biological wastewater treatment methods are two major types of microbial aggregates which are complex ecosystem containing highly stratified microbial communities [1, 2]. Electronic supplementary material The online version of this article (https://doi.org/10.1007/s00449-020-02403-8) contains supplementary material, which is available to authorized users. * Zonglian She [email protected] 1
Key Lab of Marine Environment and Ecology, Ministry of Education, Ocean University of China, Qingdao 266100, China
College of Environmental Science and Engineering, Ocean University of China, Qingdao 266100, China
2
Biofilms adhered on and within carriers form tight aggregates, while S-sludge freely disperses in solution. Suspended and attached biomass may function differently in terms of nutrient removal due to the difference in sludge retention time (SRT), physical structure and
Data Loading...
