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Effect of carbon-to-nitrogen ratio on high-rate nitrate removal in an upflow sludge blanket reactor for polluted raw water pre-treatment application
- Source :
- Sustainable Environment Research, Vol 31, Iss 1, Pp 1-10 (2021)
- Publication Year :
- 2021
- Publisher :
- BMC, 2021.
-
Abstract
- The drinking water treatment plants (DWTPs) in the developing countries urgently need an efficient pre-treatment for nitrate (NO3−) removal to cope with the increasing NO3−pollution in raw water. An upflow sludge blanket (USB) reactor applied for NO3−removal from domestic wastewater may be adopted by the DWTPs. However, studies on the optimal carbon-to-nitrogen ratio (C/N) and operation of USB reactor at short hydraulic retention times (HRT) for high-rate polluted raw water pre-treatment are lacking. In this study, we first investigated the optimal C/N for biological NO3−removal in a sequencing batch reactor (SBR). An USB reactor was then operated with the optimal C/N for pre-treating synthetic raw water contaminated with NO3−(40 mg N L− 1) to monitor the NO3−removal performance and to examine opportunities for reducing the HRT. After operating the SBR with designed C/N of 4, 3 and 2 g C g− 1N, we selected C/N of 3 g C g− 1N as the optimal ratio due to the lower carbon breakthrough and nitrite (NO2−) accumulation in the SBR. The USB reactor achieved complete NO3−and NO2−removal with a lower designed C/N of 2 g C g− 1N due to the longer sludge retention time when compared with that of SBR (10 d). The high specific denitrification rate (18.7 ± 3.6 mg N g− 1mixed liquor volatile suspended solids h− 1) suggested a possible HRT reduction to 36 min. We successfully demonstrated an USB reactor for high-rate NO3−removal, which could be a promising technology for DWTPs to pre-treat raw water sources polluted with NO3−.
- Subjects :
- Environmental Engineering
Denitrification
Carbon-to-nitrogen ratio
020209 energy
Sequencing batch reactor
02 engineering and technology
010501 environmental sciences
01 natural sciences
lcsh:TD1-1066
chemistry.chemical_compound
Nitrate
0202 electrical engineering, electronic engineering, information engineering
Raw water
lcsh:Environmental technology. Sanitary engineering
Waste Management and Disposal
0105 earth and related environmental sciences
Water Science and Technology
Renewable Energy, Sustainability and the Environment
Nitrate contamination
Pulp and paper industry
Pollution
Sludge retention time
Wastewater
chemistry
Volatile suspended solids
Environmental science
Water treatment
Hydraulic retention time
Subjects
Details
- Language :
- English
- ISSN :
- 24682039
- Volume :
- 31
- Issue :
- 1
- Database :
- OpenAIRE
- Journal :
- Sustainable Environment Research
- Accession number :
- edsair.doi.dedup.....c0f9ff1f51e056a30a446a0950dd6c0b