Inhibitory effect of silver on activated sludge: effect of organic substrate and the carbon to nitrogen ratio

2015 ◽  
Vol 91 (4) ◽  
pp. 1190-1198 ◽  
Author(s):  
Ferhan Çeçen ◽  
Başak Kılıç
Keyword(s):  
Activated Sludge ◽  
Inhibitory Effect ◽  
Organic Substrate ◽  
Carbon To Nitrogen Ratio ◽  
Nitrogen Ratio

scholarly journals Shifts in the Microbial Community of Activated Sludge with Different COD/N Ratios or Dissolved Oxygen Levels in Tibet, China

2019 ◽  
Vol 11 (8) ◽  
pp. 2284 ◽  
Author(s):  
Jin Xu ◽  
Peifang Wang ◽  
Yi Li ◽  
Lihua Niu ◽  
Zhen Xing
Keyword(s):  
Dissolved Oxygen ◽  
Activated Sludge ◽  
Sewage Treatment ◽  
Treatment Plant ◽  
Oxygen Demand ◽  
Operational Taxonomic Unit ◽  
Carbon To Nitrogen Ratio ◽  
Urban Sewage ◽  
Treatment Performance ◽  
Nitrogen Ratio

In this study, we examined the influence of the organic carbon-to-nitrogen ratio (chemical oxygen demand (COD/N)) and dissolved oxygen (DO) levels on the removal efficiency of pollutants and on the change in total microflora in the cyclic activated sludge system (CASS) in the Nyingchi prefecture in Tibet. The results demonstrated that the treatment performance was the best when the COD/N ratio was 7:1 or the DO levels were 2–2.5 mg/L in comparison with four different tested COD/N ratios (4:1, 5:1, 7:1, and 10:1) and DO concentrations (0.5–1, 1–2, 2–2.5, and 2.5–3.5 mg/L). The treatment performance can be explained by the relative operational taxonomic unit richness and evenness of the microbial communities in activated sludge. Evident microbial variance was observed, especially different COD/N ratios and DO concentrations, which were conducive to the disposal of urban sewage in plateaus. The results help to understand sewage treatment under different COD/N ratios or DO concentrations on plateaus. This work provides practical guidance for the operation of any wastewater treatment plant on a plateau.

Optimization of the carbon to nitrogen ratio for mainstream deammonification and the resulting shift in nitrification from biofilm to suspension

2020 ◽  
Vol 6 (12) ◽  
pp. 3415-3427
Author(s):  
Paul Roots ◽  
Alex F. Rosenthal ◽  
Quan Yuan ◽  
Yubo Wang ◽  
Fenghua Yang ◽  
...  
Keyword(s):  
Activated Sludge ◽  
Carbon To Nitrogen Ratio ◽  
Fixed Film ◽  
Nitrogen Ratio ◽  
Tin Removal

Mainstream deammonification performance in an integrated fixed film activated sludge (IFAS) reactor improved from 46% to 73% TIN removal after routing 10% of the primary effluent around the A-stage reactor.

Influence of carbon to nitrogen ratio on nitrous oxide emission in an Integrated Fixed Film Activated Sludge Membrane BioReactor plant

2018 ◽  
Vol 176 ◽  
pp. 1078-1090 ◽  
Author(s):  
Giorgio Mannina ◽  
George A. Ekama ◽  
Marco Capodici ◽  
Alida Cosenza ◽  
Daniele Di Trapani ◽  
...  
Keyword(s):  
Nitrous Oxide ◽  
Activated Sludge ◽  
Membrane Bioreactor ◽  
Nitrous Oxide Emission ◽  
Carbon To Nitrogen Ratio ◽  
Fixed Film ◽  
Nitrogen Ratio

Design Consideration Regarding Phosphate Removal in Activated Sludge Plants

1983 ◽  
Vol 15 (3-4) ◽  
pp. 319-328 ◽  
Author(s):  
James L Barnard
Keyword(s):  
Activated Sludge ◽  
Phosphate Removal ◽  
Practical Consideration ◽  
Design Consideration ◽  
Anaerobic Conditions ◽  
Carbon To Nitrogen Ratio ◽  
Proper Functioning ◽  
Ammonia Conversion ◽  
Nitrogen Ratio ◽  
Low Levels

This paper enumerates various practical consideration concerning the design and operation of activated sludge plants for the removal of phosphates. When phosphate removal is required without the conversion of ammonia to nitrates, either the Pho-strip or the Phoredox processes could be used. If ammonia conversion and/or the removal of nitrogen are also required, the use of the Phoredox process in combination with internal nitrification and denitrification would be required. Nitrates, when formed in the process should be removed to sufficiently low levels through internal denitrification so that they will not prevent anaerobic conditions of being maintained at all times in the anaerobic basin. Factors that may influence the proper functioning of the plant include temperature, pH, carbon to nitrogen ratio, septicity of the sewage, operator input, DO control, sludge age and clarifier design.

Effect of carbon to nitrogen ratio on the composition of microbial extracellular polymers in activated sludge

2001 ◽  
Vol 44 (10) ◽  
pp. 221-229 ◽  
Author(s):  
B. Durmaz ◽  
F.D. Sanin
Keyword(s):  
Activated Sludge ◽  
Protein Concentration ◽  
Polymer Composition ◽  
Relative Distribution ◽  
Extracellular Polymers ◽  
Carbon To Nitrogen Ratio ◽  
Carbohydrate Concentration ◽  
Low Carbohydrate ◽  
Nitrogen Ratio ◽  
Extracellular Polymer

Effect of carbon to nitrogen ratio (C/N) on the sludge extracellular polymer composition is studied in synthetically fed semi-continuous reactors with 8 days of sludge age. Results show that C/N ratio influences the relative distribution of polymer carbohydrate and protein. At low C/N ratio of 5, polymer extracts have high protein and low carbohydrate content. As the C/N ratio is increased to 17.5 and then to 40, carbohydrate concentration increases sharply and protein concentration decreases.

Automatic monitoring of denitrification rates and capacities in activated sludge processes using fluorescence or redox potential

1998 ◽  
Vol 37 (12) ◽  
pp. 121-129 ◽  
Author(s):  
S. Isaacs ◽  
Terry Mah ◽  
S. K. Maneshin
Keyword(s):  
Biological Activity ◽  
Activated Sludge ◽  
Redox Potential ◽  
Treatment Plant ◽  
Automatic Monitoring ◽  
Organic Substrate ◽  
Anoxic Zone ◽  
Optimal Dosing ◽  
Denitrifying Microorganisms ◽  
Activated Sludge Processes

A novel method is described to automatically estimate several key parameters affecting denitrification in activated sludge processes: the nitrate concentration, the denitrification capacity, and the maximum (substrate unlimited) and actual denitrification rates. From these, the concentration of active denitrifying microorganisms and the quality of available organic substrate pool can be estimated. Additionally, a modification of the method allows the determination of the efficacy of various carbon substrates to enhance denitrification, and this can be used to determine optimal dosing rates of an external carbon source. The method is based on measurements of either fluorescence or redox potential (ORP) in an isolated mini-reactor, the Biological Activity Meter (BAM), situated in the anoxic zone of the wastewater treatment plant. Advantages of the method are that it is in situ, operating at the same temperature as in the measured anoxic zone, requires no pumps or pipes for mixed liquor sampling, consumes little or no reagents, and uses measurement signals which are instantaneous and low maintenance, one of which provides a direct measure of biological activity.

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