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.

The Influence of Nitrogen on Phosphorus Removal in Activated Sludge Plants

1982 ◽  
Vol 14 (1-2) ◽  
pp. 31-45 ◽  
Author(s):  
J L Barnard
Keyword(s):  
Organic Carbon ◽  
Activated Sludge ◽  
Phosphorus Removal ◽  
Complete Removal ◽  
Phosphate Removal ◽  
Electron Donors ◽  
Biological Phosphorus Removal ◽  
Anaerobic Conditions ◽  
Low Level ◽  
Biological Phosphorus

This paper discusses the need for anaerobiases as a pre-requisite for phosphorus removal in activated sludge plants and the effect of nitrates on the anaerobic conditions. If the plant could be operated to avoid nitrification, biological phosphorus removal presents no problems. When nitrification is required, the nitrates must be reduced to a low level through internal denitrification. If sufficient carbon is available to ensure complete removal of the nitrates and anaerobic conditions in a specific zone in the plant, good phosphate removal can be ensured. Below COD : TKN ratios of 10 : 1 it is becoming more difficult to control the plant and special care should be taken to determine not only the quantity of organic carbon available as electron donors for removal of the nitrates but also the form in which it arrives at the plant.

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

Indirect Polyphosphate Quantification in Activated Sludge

1990 ◽  
Vol 25 (2) ◽  
pp. 161-174 ◽  
Author(s):  
Yves Comeau ◽  
Kenneth J. Hall ◽  
William K. Oldham
Keyword(s):  
Wastewater Treatment ◽  
Activated Sludge ◽  
Inorganic Phosphate ◽  
Wastewater Treatment Plants ◽  
Phosphate Removal ◽  
New Method ◽  
Biological Method ◽  
Anaerobic Conditions

Abstract An indirect biological method is presented to quantify the amount of polyphosphates in activated sludge obtained from wastewater treatment plants removing phosphate biologically. The method is based upon the property of such sludges to degrade polyphosphate reserves under anaerobic conditions as a result of acetate addition thereby releasing inorganic phosphate into solution. The addition of an excess of acetate ensures the consumption of any oxygen and nitrate, and the depletion of intracellular polyphosphates available for acetate storage. Thus, this new method offers a much easier approach than those previously available to quantify polyphosphate, one of the two storage polymers involved in the mechanism of biological phosphate removal.

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.

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