scholarly journals Simultaneous Biological Nutrient Removal from Municipal Wastewater and CO2-biofixation using Chlorella kessleri

2020 ◽  
Author(s):  
Mohammed Omar Faruque ◽  
Kazeem Ayodeji Mohammed ◽  
Mohammad Mozahar Hossain ◽  
Shaikh Abdur Razzak
Keyword(s):  
Removal Efficiency ◽  
Nutrient Removal ◽  
Municipal Wastewater ◽  
Biomass Concentration ◽  
Synthetic Wastewater ◽  
Biological Nutrient Removal ◽  
Fixation Rate ◽  
Chlorella Kessleri ◽  
Cultivation Period ◽  
Experimental Findings

Abstract Growing microalgae in tertiary wastewater offers a prospective avenue to remove and re-use the nutrients N and P simultaneously. Moreover, CO2 fixation via microalgae is a potential and promising approach of capturing and storing CO2. The impacts of various nitrogen to phosphorous ratios on the growth, nutrient removal from municipal wastewater, and the bio-fixation of CO2 using Chlorella kessleri were evaluated in this study. For this purpose, the microalgae was grown in synthetic wastewater, similar in composition to tertiary municipal wastewater, with NP ratios of 2:1, 4:1, 6:1, and 8:1 in batch photobioreactors for13 days. Biomass concentration increases at all NP ratios and the maximum biomass concentration is 606.79 mg/L at the NP ratio of 2:1. Nitrogen removal is more than 95% at all NP ratios except at 8:1, where it is only 72.4%. The removal efficiency of phosphorous is significantly affected by the NP ratio. The maximum phosphorous removal is about 97% for the NP ratio 6:1, whereas the lowest removal efficiency of about 20% is at the NP ratio of 2:1. The maximum CO2 bio-fixation rate of 89.36 mgL− 1d− 1 at the end of the first 7 days of the cultivation period is at the NP ratio of 6:1. In this study, Monod growth kinetic model based on a single substrate factor was used and the experimental findings agree well with the predictions by the model.

Nitrification Kinetics in Single-Sludge Biological Nutrient Removal Activated Sludge Systems

1992 ◽  
Vol 25 (6) ◽  
pp. 195-214 ◽  
Author(s):  
C. W. Randall ◽  
V. M. Pattarkine ◽  
S. A. McClintock
Keyword(s):  
Activated Sludge ◽  
Nutrient Removal ◽  
Municipal Wastewater ◽  
Biomass Concentration ◽  
Biological Nutrient Removal ◽  
Mixed Liquor ◽  
Nitrification Kinetics ◽  
Anoxic Zones ◽  
Complete Nitrification ◽  
Activated Sludge Systems

Nitrification kinetics as a function of mixed liquor temperature were compared for a conventional fully-aerobic activated sludge system and a system accomplishing biological nutrient removal (BNR) by incorporation of anaerobic and anoxic zones using the UCT configuration. The systems treated the same municipal wastewater and both had flow rates of 151 L/day. The nitrification rates were greater in the nutrient removal system compared to the conventional system as long as the aerobic MCRT was above the minimum for complete nitrification. It was concluded that BNR systems require less aerobic volume than fully aerobic systems to accomplish nitrification because the aerobic biomass concentration is greater in the BNR systems, particularly if the UCT configuration is used. Nonetheless, BNR systems require more total volume to accomplish complete nitrification than fully aerobic systems, and the volume differential increases as mixed liquor temperatures decrease.

Treatment of a milkpowder/butter wastewater using the AAO activated sludge configuration

1997 ◽  
Vol 36 (10) ◽  
pp. 79-86 ◽  
Author(s):  
Michael J. Donkin ◽  
John M. Russell
Keyword(s):  
Activated Sludge ◽  
Removal Efficiency ◽  
Nutrient Removal ◽  
Phosphorus Removal ◽  
Suspended Solids ◽  
Synthetic Wastewater ◽  
Biological Nutrient Removal ◽  
In Series ◽  
Aerobic Reactor ◽  
Original Size

A laboratory-scale nutrient removal activated sludge system, based on the AAO configuration, was used to treat a synthetic wastewater from a milkpowder/butter factory. In this system, substrate is fed to anaerobic and anoxic selectors in series with an aerobic reactor. Sludge is returned to the anaerobic selector, and mixed liquor from the aerobic reactor is recycled to the anoxic selector. The overall system is operated at an HRT of 7 days and a nominal sludge age of 20 days. This system was prone to prolonged bulking periods, with filamentous bacteria Sphaerotilus natans, Type 0411 and Haliscomenobacter hydrossis being identified in the mixed liquors, although effective clarifier operation prevented loss of suspended solids. Theory suggests that selectors may be used to circumvent low F:M bulking, and to bring about enhanced biological nutrient removal. An investigation of the initial design revealed that relatively high nitrite levels were present in the system, and a larger anoxic selector with an HRT of 820 minutes was substituted for the original one with an HRT of 48 minutes. This resulted in a decrease in nitrite and a equivalent increase in nitrate in the system. Overall nitrogen removal remained unchanged at 66%, and SVI levels did not improve. On resetting the anoxic selector to its original size, the effect was not reversed. Phosphorus removal efficiency was detrimentally affected by the anoxic sizing experiment (49% to 20%), and this may be linked to the raised level of nitrate in the system. COD removal efficiency remained excellent throughout the trial at over 90% removal.

Anaerobic treatment of low concentration waste water in an inverse fluidized bed reactor

2000 ◽  
Vol 41 (4-5) ◽  
pp. 245-251 ◽  
Author(s):  
P. Castilla ◽  
M. Meraz ◽  
O. Monroy ◽  
A. Noyola
Keyword(s):  
Fluidized Bed ◽  
Removal Efficiency ◽  
Suspended Solids ◽  
Municipal Wastewater ◽  
Specific Activity ◽  
Biomass Concentration ◽  
Fluidized Bed Reactor ◽  
Anaerobic Treatment ◽  
Low Concentration ◽  
Inverse Fluidized Bed

Low concentration synthetic and municipal wastewaters were treated at HRT as short as 3 and 0.6 h respectively in an anaerobic inverse fluidized bed. Both bioreactors showed gas hold up due to the liquid downflow pattern of the prototype. The bioreactor operated at 3 h had a removal efficiency of 83%, specific activity of 4.5 kg CODremoved/kg IVS (d and the gas hold up varied from 23 to 55%. The reactor treating municipal wastewater had a removal efficiency of 44% when operating at 0.6 h, the specific activity was 4.2 kg CODremoved/kg IVS (d and no biogas was detected apparently because an important fraction was dissolved in the liquid phase. The biomass concentration was 13.8 and 1.1 kg IVS/m3 for synthetic and municipal wastewater and the SEM microphotographs showed a bacterial diversity for the first run and only cocci cells for the second run. The system does not remove suspended solids, so a polishing postreatment to improve water quality has to be implemented.

Feasibility Study on Biological Nutrient Removal in Sequencing Batch Reactor Treating Municipal Wastewater

2020 ◽  
Vol 17 (2) ◽  
pp. 946-949
Author(s):  
Samaneh Alijantabar Aghouzi ◽  
Thomas S. Y. Choong ◽  
M. I. Aida Isma
Keyword(s):  
Nutrient Removal ◽  
Sequencing Batch Reactor ◽  
Municipal Wastewater ◽  
Batch Reactor ◽  
Ammonia Nitrogen ◽  
Biological Nutrient Removal ◽  
Nitrogen And Phosphorus ◽  
Bacterial Consortia ◽  
Aeration Time ◽  
Working Volume

This study elucidates the performance of sequencing batch reactor for nutrient removal from municipal wastewater. The removal of COD, ammonia nitrogen and phosphorus were investigated. The SBR with a working volume of 5 L was operated for 6 hours, with 5 min fill, 30 min settle and 5 min effluent withdrawal. The remaining time in each cycle was 90 min anaerobic phase, 130 min anoxic phase and 110 min aerobic phase. The experiment was repeated with a longer aeration time of 180 min resulting to prolong the duration cycle. In the aerobic phase, dissolved oxygen was kept in the range of more than 2 mg/L. During batch operation, the system attained stability and had a removal efficiency for ammonia nitrogen, COD and phosphorus of 51.36%, 83.33% and 99.53%, respectively. Extending the aeration period improved ammonia nitrogen removal to 54.27%. It should be noted that the stability of the granular biomass agglomerates highly depending on the bacterial consortia. The particle size of sludge reduced from 60.26 μm to 39.00 μm in 60 days. It was observed that degranulation process and biomass loss was unavoidable.

Influence of wastewater composition on biological nutrient removal in UniFed SBR process

2008 ◽  
Vol 58 (4) ◽  
pp. 803-810 ◽  
Author(s):  
C. H. Zhao ◽  
Y. Z. Peng ◽  
S. Y. Wang ◽  
X. G. Tang
Keyword(s):  
Removal Efficiency ◽  
Nutrient Removal ◽  
Phosphorus Removal ◽  
Domestic Wastewater ◽  
Biological Nutrient Removal ◽  
Detection Level ◽  
Maximum Value

The effects of influent C/N ratio and C/P ratio on biological nutrient removal performance were investigated in a lab-scale UniFed SBR apparatus treating real domestic wastewater. The results showed that TN removal efficiency increased as C/N ratio increased from 43.6% at 2.8 to 80.8% at 5.7. But when C/N ratio increased further, TN removal efficiency increased very slowly. This was because when C/N ratio was higher than 5.7, complete denitrification in the sludge blanket during feed/decant period had been achieved, TN removal efficiency during this period always kept the maximum value and only TN removal efficiency during aeration period rose as C/N ratio increased. PO43− removal efficiency increased as C/N ratio increased from 27.3% at 2.8 to 88.1% at 5.7. When C/N ratio was 6.5 and above, PO43− concentration couldn't be detected in the effluent. When influent C/N ratio and volumetric exchange ratio were fixed at 6 and 33% respectively, as C/P ratio was higher than 33, PO43− concentration of effluent always remained below the detection level and phosphorus removal efficiency kept stable at 100%, but as the C/P ratio was lower than 33, phosphorus removal efficiency increased as C/P ratio increased linearly. C/P ratio hardly affected TN removal efficiency, which always kept at 82.2%–85.8% in this study.

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