Journal
WATER RESEARCH
Volume 93, Issue -, Pages 74-83Publisher
PERGAMON-ELSEVIER SCIENCE LTD
DOI: 10.1016/j.watres.2016.02.009
Keywords
Denitrifying biofilter; Solid carbon resource; Polycaprolactone; Post-denitrification; High-throughput sequencing
Funding
- National Water Pollution Control and Treatment Science and Technology Major Project of China [2012ZX07205-001]
- China Postdoctoral Science Foundation [2014M560982]
Ask authors/readers for more resources
Tertiary nitrogen removal technologies are needed to reduce the excess nitrogen that is discharged into sensitive aquatic ecosystems. An integrated solid-phase denitrification biofilter (SDNF) was developed with dual media to remove nitrate and suspended solids (SS) from the secondary effluent of municipal wastewater treatment plants. Biodegradable polymer pellets of polycaprolactone (PCL) served as the biofiltration medium and carbon source for denitrification. Long-term continuous operation of the SDNF was conducted with real secondary effluent to evaluate the denitrification performance and effects of influent nitrate loading rates (NLR) and operating temperatures. The results indicated that both nitrate and SS were effectively removed. The SDNF had a strong tolerance for fluctuations in influent NLR, and a maximum denitrification rate of 3.80 g N/(L.d) was achieved. The low temperature had a significant impact on nitrogen removal, yet the denitrification rate was still maintained at a relative high level to as much as 1.23 g N/(L.d) even at approximately 8.0 degrees C in winter. Nitrite accumulation and excessive organics residue in the effluent were avoided throughout the whole experiment, except on occasional days in the lag phase. The observed biomass yield was calculated to be 0.44 kgVSS/kgPCL. The microbial diversity and community structure of the biofilm in the SDNF were revealed by Illumina high-throughput sequencing. The special carbon source led to an obvious succession of microbial community from the initial inoculum (activated sludge from aerobic tanks), and included a decrease in microbial diversity and a shift in the dominant groups, which were identified to be members of the family Comamonadaceae in the SDNF. The SDNF developed in this study was verified to be an efficient technology for tertiary nitrogen removal from secondary effluent. (C) 2016 Elsevier Ltd. All rights reserved.
Authors
I am an author on this paper
Click your name to claim this paper and add it to your profile.
Reviews
Recommended
No Data Available