Biochar Addition in Membrane Bioreactor Enables Membrane Fouling Alleviation and Nitrogen Removal Improvement for Low C/N Municipal Wastewater Treatment
Abstract
:1. Introduction
2. Materials and Methods
2.1. Experiment Rig Set-Up and Operating Conditions
2.2. Biochar Characteristics
2.3. Biochar Carbon Source Release Experiment
2.4. Membrane Fouling Analysis
2.5. Microbial Community Analyses
2.6. Analytical Methods
3. Results and Discussion
3.1. Impact of Biochar Addition on Membrane Bioreactor Treatment Performance
3.2. Impact of Biochar Addition on Mixed Liquor Suspensions
3.3. Impact of Biochar Addition on Membrane Fouling Propensity and Fouling Mechanism
3.4. Impact of Biochar Addition on Microbial Diversity
4. Conclusions
- Biochar addition can enable membrane fouling alleviation and nitrogen removal improvement.
- Biochar addition can effectively alleviate membrane fouling because of the change of mixed liquor, such as lower SMP content reduction by about 14%, lower SMP P/C ratio from 0.28 ± 0.02 to 0.22 ± 0.03, smaller SMP molecular weight and bigger particle size from 67.68 ± 6.9 μm to 113.47 ± 4.8 μm. This can be mainly ascribed to the biochar adsorption capacity and facilitate the formation of bigger flocs with the carbon skeleton in biochar as a core.
- The improved nitrogen removal after biochar addition can be due to the initial carbon source release from biochar and formation of aerobic–anaerobic microstructures.
- Microbial diversity analysis results suggested more accumulation of denitrification microbes, including norank_f__JG30-KF-CM45 and Plasticicumulans. A less relative abundance of Aeromonas after biochar addition suggested less EPS secretion, thus reducing the rate of membrane fouling.
- Further studies about biochar modification and carbon source release kinetics should be conducted in order to increase the carbon source content, control the release rate and fit the carbon source demand from the denitrification bacteria. Additionally, the cost analyses of biochar addition on long-term performance should be carried out.
Supplementary Materials
Author Contributions
Funding
Institutional Review Board Statement
Informed Consent Statement
Data Availability Statement
Conflicts of Interest
References
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Parameter | CMBR | BMBR | ||
---|---|---|---|---|
Effluent Characteristics mg L−1 | Removal % | Effluent Characteristics mg L−1 | Removal % | |
COD | 9.8 ± 0.9 | 96.4 ± 0.3 | 5.5 ± 0.9 | 97.9 ± 0.3 |
NH4+-N | 0.8 ± 0.05 | 98.2 ± 0.1 | 0.7 ± 0.05 | 98.4 ± 0.1 |
NO3−-N | 21.1 ± 1.5 | - | 16.7 ± 1.2 * | - |
TN | 21.9 ± 1.5 | 62.3 ± 0.5 | 17.4 ± 1.2 * | 70.1 ± 0.6 * |
Parameter | SVI (mL/g) | SV30 (%) | Particle Size (μm) | Zeta Potential (−mV) |
---|---|---|---|---|
CMBR | 128.1 ± 6 | 98.0 ± 0.8 | 67.68 ± 6.9 | 20.6 ± 0.44 |
BMBR | 90.5 ± 7 | 87.0 ± 0.8 | 113.47 ± 4.8 | 19.4 ± 0.30 |
Rt | Rm | Rp | Rc | |
---|---|---|---|---|
CMBR (×1012 m−1) | 6.68 | 1.45 | 0.41 | 4.82 |
Percent of Rt | 100% | 21.74% | 6.10% | 72.16% |
BMBR (×1012 m−1) | 6.70 | 1.45 | 0.079 | 5.17 |
Percentage of Rt | 100% | 21.66% | 1.18% | 77.16% |
Sample/Estimators | Shannon | Simpson | Ace | Chao | Pd | OTU |
---|---|---|---|---|---|---|
CMBR | 4.426 | 0.043 | 863.633 | 863.065 | 84.134 | 776 |
BMBR | 4.651 | 0.043 | 967.221 | 973.280 | 93.096 | 890 |
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Wang, K.; Ye, Q.; Shen, Y.; Wang, Y.; Hong, Q.; Zhang, C.; Liu, M.; Wang, H. Biochar Addition in Membrane Bioreactor Enables Membrane Fouling Alleviation and Nitrogen Removal Improvement for Low C/N Municipal Wastewater Treatment. Membranes 2023, 13, 194. https://doi.org/10.3390/membranes13020194
Wang K, Ye Q, Shen Y, Wang Y, Hong Q, Zhang C, Liu M, Wang H. Biochar Addition in Membrane Bioreactor Enables Membrane Fouling Alleviation and Nitrogen Removal Improvement for Low C/N Municipal Wastewater Treatment. Membranes. 2023; 13(2):194. https://doi.org/10.3390/membranes13020194
Chicago/Turabian StyleWang, Kanming, Qiaoqiao Ye, Yuxiang Shen, Yajing Wang, Qiankun Hong, Chenlong Zhang, Min Liu, and Hongyu Wang. 2023. "Biochar Addition in Membrane Bioreactor Enables Membrane Fouling Alleviation and Nitrogen Removal Improvement for Low C/N Municipal Wastewater Treatment" Membranes 13, no. 2: 194. https://doi.org/10.3390/membranes13020194