Enhanced Nitrogen Removal in a Pilot-Scale Anoxic/Aerobic (A/O) Process Coupling PE Carrier and Nitrifying Bacteria PE Carrier: Performance and Microbial Shift
Abstract
:1. Introduction
2. Materials and Methods
2.1. Operational Procedures of A/O and IFAS Systems
2.2. Seeding Sludge and Real Municipal Wastewater
2.3. Analytical Methods
2.4. Sludge Samples Collection and DNA Extraction
2.5. PCR Amplification and 16S rRNA Sequencing
2.6. High-Throughput Sequence Processing
3. Results and Discussion
3.1. Operational Parameters of IFAS and A/O Systems
3.2. Long-Term Performances of IFAS and A/O Systems
3.3. Enhancing Nitrogen Removal Mechanism of IFAS Process
3.4. Changing Trends of Community Diversity between IFAS and A/O Systems
3.5. Taxonomic Compositional Changes in IFAS and A/O Systems
3.6. Succession of Nitrogen Removal Genera in IFAS and A/O Systems
3.7. Potential Application of the NBPE Carriers in A/O Wastewater Treatment Plants
4. Conclusions
Supplementary Materials
Author Contributions
Funding
Conflicts of Interest
Abbreviations
IFAS | Integrated fixed-film activated sludge technology |
A/O | Anoxic/aerobic process |
PE | Polyethylene |
PUF | Polyurethane foam |
NBPE | Nitrifying bacteria polyethylene carrier |
AS | Activated sludge |
HDB | Heterotrophic denitrifying bacteria |
HNAD | Heterotrophic nitrification and aerobic denitrification bacteria |
AOB | Ammonia oxidizing bacteria |
NOB | Nitrite oxidizing bacteria |
HRT | Hydraulic retention time |
WWTPs | Wastewater treatment plants |
DO | Dissolved oxygen |
TN | Total nitrogen |
OTU | Operational taxonomic units |
PCR | Polymerase chain reaction |
DTC | Designed treatment capacity |
FA | Free ammonia |
R | Sludge reflux ratio |
RT | Total recycle ratio of system, including R and nitrifying recycle ratio |
EBPR | Enhanced biological phosphorus removal |
SND | Simultaneous nitrification and denitrification |
HR | Heterotrophic respiration |
HD | Heterotrophic denitrification |
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Operational Parameters | Units | Phase 0 (Start-Up) | Phase 1 | Phase 2 | ||||
---|---|---|---|---|---|---|---|---|
IFAS | A/O | IFAS | A/O | IFAS | A/O | |||
Operational time | day | 40 | 40 | 60 | 60 | 100 | 100 | |
Carrier fill ratio | % | 35 | 0 | 35 | 0 | 35 | 0 | |
Temperature | °C | 24–26 | 24–26 | 18~23 | 18~23 | 16~18 | 16~18 | |
Influent | m3/d | 5–10 | 5–10 | 10~40 | 10~40 | 10~40 | 10~40 | |
DO in Aerobic tank | mg/L | 4.0 ± 1.0 | 4.0 ± 1.0 | 4.0 ± 1.0 | 4.0 ± 1.0 | 4.0 ± 1.0 | 4.0 ± 1.0 | |
DO in Anoxic tank | mg/L | 0.10 | 0.08 | 0.10 | 0.05 | 0.15 | 0.03 | |
pH | / | 6.8~7.2 | 6.8~7.2 | 6.8~7.2 | 6.8~7.2 | 7.0~7.2 | 7.0~7.2 | |
Total HRT | Periods 1 and 5 | h | 7.2–14.4 | 7.2–14.4 | 7.2 | 7.2 | 7.2 | 7.2 |
Periods 2 and 6 | h | 3.6 | 3.6 | 3.6 | 3.6 | |||
Periods 3 and 7 | h | 2.4 | 2.4 | 2.4 | 2.4 | |||
Periods 4 and 8 | h | 1.8 | 1.8 | 1.8 | 1.8 | |||
SRT | day | 40–60 | 40–60 | 15 ± 1.6 | 15 ± 1.6 | 25 ± 5 | 25 ± 5 | |
Sludge reflux ratio (R) | % | 50–200 | 50–200 | 100 | 100 | 100 | 100 | |
SVI | mL/g | 223 ± 16 | 135 ± 19 | 118 ± 15 | 109 ± 11 | 132 ± 13 | 105 ± 9 | |
C/N ratio | / | 5.9 | 5.9 | 6.6 | 6.6 | 7.7 | 7.7 | |
MLVSS of AS | mg/L | 5500 ± 180 | 5500 ± 200 | 4050 ± 255 | 4100 ± 125 | 4250 ± 375 | 3850 ± 325 | |
VSS of biofilm | mg/L | 0–1650 | 0 | 1650 ± 125 | 0 | 1575 ± 155 | 0 |
Experiment Phase | Effluent NH4+-N (mg/L) | NH4+-N Removal Rate (%) | Effluent TN (mg/L) | TN Removal Rate (%) | Effluent COD (mg/L) | COD Removal Rate (%) | |||||||
---|---|---|---|---|---|---|---|---|---|---|---|---|---|
IFAS | A/O | IFAS | A/O | IFAS | A/O | IFAS | A/O | IFAS | A/O | IFAS | A/O | ||
Phase 1 | Period 1 (1–15 d) | 0.2 ± 0.1 | 0.3 ± 0.2 | 98.6 ± 0.7 | 97.7 ± 1.1 | 13.9 ± 1.8 | 14.2 ± 2.0 | 35.1 ± 12.8 | 33.2 ± 14.5 | 22.3 ± 7.2 | 21.6 ± 3.5 | 79.3 ± 12.4 | 81.1 ± 5.0 |
Period 2 (16–30 d) | 0.3 ± 0.2 | 0.6 ± 0.1 | 97.8 ± 1.3 | 96.3 ± 1.0 | 14.6 ± 3.2 | 15.5 ± 3.2 | 34.8 ± 12.7 | 30.8 ± 11.2 | 22.9 ± 5.9 | 21.3 ± 5.2 | 85.9 ± 3.9 | 86.9 ± 3.2 | |
Period 3 (31–45 d) | 0.7 ± 1.1 | 5.1 ± 1.9 | 94.8 ± 7.2 | 61.5 ± 12.9 | 12.3 ± 2.7 | 14.9 ± 2.9 | 47.6 ± 9.6 | 35.7 ± 15.1 | 22.3 ± 6.3 | 23.9 ± 7.3 | 87.6 ± 3.6 | 86.7 ± 4.1 | |
Period 4 (46–60 d) | 6.9 ± 2.4 | 9.6 ± 3.1 | 56.1 ± 10.4 | 38.7 ± 12.1 | 18.8 ± 6.9 | 25.4 ± 8.1 | 20.7 ± 9.5 | −8.5 ± 13.3 | 29.1 ± 3.2 | 27.9 ± 2.3 | 76.6 ± 9.9 | 77.8 ± 7.9 | |
Phase 2 | Period 5 (61–85 d) | 0.2 ± 0.2 | 0.6 ± 0.2 | 98.7 ± 1.0 | 96.4 ± 1.2 | 14.3 ± 2.2 | 16.3 ± 4.7 | 37.6 ± 7.7 | 30.9 ± 6.9 | 22.3 ± 5.1 | 21.6 ± 3.4 | 84.5 ± 7.1 | 85.4 ± 3.4 |
Period 6 (86–105 d) | 0.3 ± 0.2 | 1.0 ± 0.5 | 98.2 ± 1.4 | 93.8 ± 3.4 | 15.3 ± 2.5 | 15.5 ± 2.4 | 28.7 ± 3.7 | 28.6 ± 3.6 | 21.9 ± 4.6 | 26.7 ± 5.8 | 87.7 ± 3.1 | 85.3 ± 2.5 | |
Period 7 (106–135 d) | 0.6 ± 0.4 | 6.6 ± 2.2 | 95.3 ± 3.8 | 55.1 ± 23.2 | 15.5 ± 4.2 | 15.7 ± 4.1 | 29.1 ± 5.8 | 28.0 ± 4.7 | 33.2 ± 7.2 | 39.7 ± 10.2 | 80.8 ± 4.4 | 76.6 ± 8.0 | |
Period 8 (136–160 d) | 3.9 ± 1.9 | 11.8 ± 4.9 | 73.0 ± 7.9 | 18.9 ± 8.8 | 14.3 ± 4.3 | 20.6 ± 6.1 | 25.5 ± 5.6 | −7.6 ± 15.7 | 45.1 ± 7.2 | 53.6 ± 9.2 | 66.1 ± 8.5 | 59.3 ± 11.6 |
Operational Parameters | Units | IFAS at Phase 2 | A/O at Phase 2 | IFAS at Phase 1 | A/O at Phase 1 |
---|---|---|---|---|---|
Extremely treatment capacity | m3/d | 40 | 20 | 30 | 20 |
Extremely HRT | h | 1.8 | 3.6 | 2.4 | 3.6 |
Carrier types | / | NBPE | Without | PE | Without |
Extremely shock load | % | 400 | 200 | 300 | 200 |
Treatment capacity increase rate | % | 100 | 0 | 50 | 0 |
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Gu, S.; Liu, L.; Zhuang, X.; Qiu, J.; Zhou, Z. Enhanced Nitrogen Removal in a Pilot-Scale Anoxic/Aerobic (A/O) Process Coupling PE Carrier and Nitrifying Bacteria PE Carrier: Performance and Microbial Shift. Sustainability 2022, 14, 7193. https://doi.org/10.3390/su14127193
Gu S, Liu L, Zhuang X, Qiu J, Zhou Z. Enhanced Nitrogen Removal in a Pilot-Scale Anoxic/Aerobic (A/O) Process Coupling PE Carrier and Nitrifying Bacteria PE Carrier: Performance and Microbial Shift. Sustainability. 2022; 14(12):7193. https://doi.org/10.3390/su14127193
Chicago/Turabian StyleGu, Shengbo, Leibin Liu, Xiaojie Zhuang, Jinsheng Qiu, and Zhi Zhou. 2022. "Enhanced Nitrogen Removal in a Pilot-Scale Anoxic/Aerobic (A/O) Process Coupling PE Carrier and Nitrifying Bacteria PE Carrier: Performance and Microbial Shift" Sustainability 14, no. 12: 7193. https://doi.org/10.3390/su14127193
APA StyleGu, S., Liu, L., Zhuang, X., Qiu, J., & Zhou, Z. (2022). Enhanced Nitrogen Removal in a Pilot-Scale Anoxic/Aerobic (A/O) Process Coupling PE Carrier and Nitrifying Bacteria PE Carrier: Performance and Microbial Shift. Sustainability, 14(12), 7193. https://doi.org/10.3390/su14127193