Effect of carbon to nitrogen ratio on the physical and chemical properties of activated sludge

Date

2003-11-01

Author

Durmaz, B
Sanin, Faika Dilek

Metadata

Show full item record

This work is licensed under a Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International License.

Item Usage Stats

194
views

0
downloads

The effect of carbon to nitrogen ratio (C/N) of the feed on the physical and surface chemical properties of activated sludge is investigated. Semi-continuous reactors with 2 liters volume were operated at a mean cell residence time of 8 days. These mixed culture reactors were operated at 3 different carbon to nitrogen ratio. The operation of conventional activated sludge plants treating municipal wastewater is represented with reactors having a C/N ratio of 21 (in terms of the ratio of COD to TKN). Carbon and nitrogen limited activated sludge systems are represented by reactors with a C/N ratio of 9 and 43, respectively. The results show that C/N ratio has a profound effect on the ultimate physical and surface chemical properties of activated sludge. Both the steady state microorganism concentration and the amount of microbial extracellular polymers produced increase with increasing C/N ratio. The sludge becomes much harder to dewater and settle and it becomes more viscous as the C/N ratio increases. A decrease in surface hydrophobicity and an increase in surface charge of the sludge accompany these physical changes.

Subject Keywords

Activated sludge, Carbon to nitrogen ratio, Extracellular polymers, Physical properties, Surface characteristics

URI

https://hdl.handle.net/11511/49022

Journal

ENVIRONMENTAL TECHNOLOGY

DOI

https://doi.org/10.1080/09593330309385677

Collections

Department of Environmental Engineering, Article

Suggestions

OpenMETU
Core

Effect of carbon to nitrogen ratio on the composition of microbial extracellular polymers in activated sludge Durmaz, B; Sanin, Faika Dilek (2001-01-01) 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.
Effect of EDTA on activated sludge properties Sanin, Faika Dilek (2001-02-01) Bacterial extracellular polymers have been found to be important in bioflocculation of activated sludge. In this study ethylene diamine tetra acetic acid (EDTA) method of extracting bacterial extracellular polymers is examined. Following extractions, it is observed that EDTA extracted significant amounts of biopolymers. However, the chemical treatment causes serious changes in sludge properties. Sludge particle size is reduced from 21 mum to 14.6 mum, filtration properties of sludge deteriorates, indicated ...
Effect of carbon nanotube surface treatment on the morphology, electrical, and mechanical properties of the microfiber-reinforced polyethylene/poly(ethylene terephthalate)/carbon nanotube composites Yesil, Sertan; Bayram, Göknur (2013-01-15) The aim of this study is to investigate the effects of carbon nanotube (CNT) chemical properties, CNT content, and molding temperature on the morphology, electrical, and mechanical properties of the microfiber-reinforced polymer composites. These composites were prepared by extrusion and hot stretching the poly(ethylene terephthalate) (PET)/CNT phase in high density polyethylene (HDPE) matrix. Surfaces of the CNT were modified by purification with strong acid mixture (HNO3 : H2SO4 mixture 1 : 1 by volume) f...
EFFECT OF ELECTRON AND GAMMA-RAY IRRADIATION ON THE CHEMICAL-COMPOSITION AND ATOMIC DISTRIBUTION OF COPPER-BASED AND IRON-BASED ALLOYS BINNATOV, KG; RODIONOV, YL; Mehrabov, Amdulla; ALIZADE, II (1990-01-01) This paper reports that the oxygen, hydrogen, carbon, nitrogen, and sulfur contents of steels and alloys can vary as a result of irradiation by electrons and gamma rays at comparatively low temperatures. As this takes place, the materials can be either saturated with these elements, or these elements can be removed from the irradiated materials, depending on the irradiation medium. Transformations are initiated as a result of radiation-stimulated oxygenation of copper-iron, iron-manganese, and iron-nickel a...
Effect of Pd loading in Pd-Pt bimetallic catalysts doped into hollow core mesoporous shell carbon on performance of proton exchange membrane fuel cells Ficicilar, Berker; BAYRAKÇEKEN YURTCAN, Ayşe; Eroğlu, İnci (2009-08-01) A significantly active Pd-Pt/carbon electrocatalyst for polymer electrolyte membrane fuel cells was synthesized by microwave irradiation using a hollow core mesoporous shell (HCMS) carbon as catalyst support that was prepared by template replication of core/shell spherical silica particles and two different carbon precursors. Pt/Pd percent weight ratios on carbon support were varied as 20/0, 15/5, 10/10, 5/15 to 0/20. As the average pore diameter of the carbon support was increased from 3.02 nm to 3.90 nm b...

Citation Formats

B. Durmaz and F. D. Sanin, “Effect of carbon to nitrogen ratio on the physical and chemical properties of activated sludge,” ENVIRONMENTAL TECHNOLOGY, pp. 1331–1340, 2003, Accessed: 00, 2020. [Online]. Available: https://hdl.handle.net/11511/49022.