Minimizing nitrous oxide in biological nutrient removal from municipal wastewater by controlling copper ion concentrations

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.

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A novel A-B process for enhanced biological nutrient removal in municipal wastewater reclamation

Chemosphere ◽

10.1016/j.chemosphere.2017.09.049 ◽

2017 ◽

Vol 189 ◽

pp. 39-45 ◽

Cited By ~ 11

Author(s):

Guangjing Xu ◽

Han Wang ◽

Jun Gu ◽

Nan Shen ◽

Zheng Qiu ◽

...

Keyword(s):

Nutrient Removal ◽

Municipal Wastewater ◽

Biological Nutrient Removal ◽

Wastewater Reclamation

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

10.21203/rs.3.rs-41636/v1 ◽

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.

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