Reduced Growth Yield of Activated Sludge in Organic Protonophore-Containing Batch Culture

2000 ◽  
Vol 39 (2) ◽  
pp. 168-173 ◽  
Author(s):  
Y. Liu *, †
Keyword(s):  
Activated Sludge ◽  
Batch Culture ◽  
Growth Yield

Minimization of activated sludge production by chemically stimulated energy spilling

2000 ◽  
Vol 42 (12) ◽  
pp. 189-200 ◽  
Author(s):  
G.-H. Chen ◽  
H.-K. Mo ◽  
S. Saby ◽  
W.-k. Yip ◽  
Y. Liu
Keyword(s):  
Activated Sludge ◽  
Growth Yield ◽  
Dry Weight ◽  
Staining Technique ◽  
Microbial Culture ◽  
Dapi Staining ◽  
E Coli ◽  
Energy Spilling ◽  
Activated Sludge Processes ◽  
Sludge Production

Minimization of excess sludge production in activated sludge processes has been pursued around the world in order to meet stringent environmental regulations on sludge treatment and disposal. To achieve this goal, physical, chemical, and biological approaches have been proposed. In this paper, a chemical compound, 3,3′,4′,5-tetrachlorosalicylanilide (TCS) was tested for enhancing microbial energy spilling of the sludgeso as to minimize its growth. In order to examine this, an exploratory study was conducted using both batch and continuous activated sludge cultures. Batch experiments with these two cultures were carried out at different initial concentrations of TCS. It has been confirmed that an addition of TCS is effective in reducing the production of both the sludge cultures, particularly the continuous culture where the observed growth yield was reduced by around 70%, when the initial TCS concentration was 0.8 ppm. Meanwhile, the substrate removal activity of this culture was found not to be affected at this TCS concentration. To further evaluate the TCS effect, a pure microbial culture of E. coli was employed. Batch experiment results with this culture implied that TCS might be able to reduce the cell density of E. coli drastically when an initial TCS concentration was greater than 0.12 ppm. It was also found that TCS was not toxic to this type of bacteria. Microscopic examinations with a 4′, 6-diamidino-2-phenylindole (DAPI) staining technique revealed that TCS neither affected the cell division nor altered the cell size of E. coli. However, both the cell ATP content and the cell dry weight were reduced significantly with the addition of TCS.

Response of activated sludge to the presence of 2,4-dichlorophenol in a batch culture system

2006 ◽  
Vol 41 (8) ◽  
pp. 1758-1763 ◽  
Author(s):  
Guo-Wei Chen ◽  
Han-Qing Yu ◽  
Hui-Xiong Liu ◽  
De-Qian Xu
Keyword(s):  
Activated Sludge ◽  
Batch Culture ◽  
Culture System

scholarly journals The role of oxygen limitation in the formation of poly-β-hydroxybutyrate during batch and continuous culture of Azotobacter beijerinckii

1972 ◽  
Vol 128 (5) ◽  
pp. 1193-1201 ◽  
Author(s):  
P. J. Senior ◽  
G. A. Beech ◽  
G. A. F. Ritchie ◽  
E. A. Dawes
Keyword(s):  
Batch Culture ◽  
Growth Rates ◽  
Reducing Power ◽  
Growth Yield ◽  
Dry Weight ◽  
Oxygen Limitation ◽  
Co2 Production ◽  
Mineral Salts ◽  
Production Values ◽  
Chemostat Cultures

Azotobacter beijerinckii was grown in ammonia-free glucose–mineral salts media in batch culture and in chemostat cultures limited by the supply of glucose, oxygen or molecular nitrogen. In batch culture poly-β-hydroxybutyrate was formed towards the end of exponential growth and accumulated to about 74% of the cell dry weight. In chemostat cultures little poly-β-hydroxybutyrate accumulated in organisms that were nitrogen-limited, but when oxygen limited a much increased yield of cells per mol of glucose was observed, and the organisms contained up to 50% of their dry weight of poly-β-hydroxybutyrate. In carbon-limited cultures (D, the dilution rate,=0.035–0.240h−1), the growth yield ranged from 13.1 to 19.8g/mol of glucose and the poly-β-hydroxybutyrate content did not exceed 3.0% of the dry weight. In oxygen-limited cultures (D=0.049–0.252h−1) the growth yield ranged from 48.4 to 70.1g/mol of glucose and the poly-β-hydroxybutyrate content was between 19.6 and 44.6% of dry weight. In nitrogen-limited cultures (D=0.053–0.255h−1) the growth yield ranged from 7.45 to 19.9g/mol of glucose and the poly-β-hydroxybutyrate content was less than 1.5% of dry weight. The sudden imposition of oxygen limitation on a nitrogen-limited chemostat culture produced a rapid increase in poly-β-hydroxybutyrate content and cell yield. Determinations on chemostat cultures revealed that during oxygen-limited steady states (D=0.1h−1) the oxygen uptake decreased to 100μl h−1 per mg dry wt. compared with 675 for a glucose-limited culture (D=0.1h−1). Nitrogen-limited cultures had CO2 production values in situ ranging from 660 to 1055μl h−1 per mg dry wt. at growth rates of 0.053–0.234h−1 and carbon-limited cultures exhibited a variation of CO2 production between 185 and 1328μl h−1 per mg dry wt. at growth rates between 0.035 and 0.240h−1. These findings are discussed in relation to poly-β-hydroxybutyrate formation, growth efficiency and growth yield during growth on glucose. We suggest that poly-β-hydroxybutyrate is produced in response to oxygen limitation and represents not only a store of carbon and energy but also an electron sink into which excess of reducing power can be channelled.

Efficiency of Biological Activator Formulated Material (BAFM) for volatile organic compounds removal – preliminary batch culture tests with activated sludge

2012 ◽  
Vol 33 (14) ◽  
pp. 1671-1676 ◽  
Author(s):  
Charline Corre ◽  
Catherine Couriol ◽  
Abdeltif Amrane ◽  
Eric Dumont ◽  
Yves Andrès ◽  
...  
Keyword(s):  
Volatile Organic Compounds ◽  
Activated Sludge ◽  
Organic Compounds ◽  
Batch Culture ◽  
Volatile Organic

scholarly journals Analysis of Nocardia amarae Profiles in Sequencing Fed-Batch Culture of Activated Sludge.

2000 ◽  
Vol 36 (2) ◽  
pp. 63-70 ◽  
Author(s):  
KEISUKE IWAHORI ◽  
HIRONORI TAKI ◽  
TAEK RYUL CHOI ◽  
MASANORI FUJITA
Keyword(s):  
Activated Sludge ◽  
Batch Culture ◽  
Fed Batch ◽  
Fed Batch Culture ◽  
Nocardia Amarae
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