Polyphasic approaches to the identification of predominant polyphosphate-accumulating organisms in a laboratory-scale anaerobic/aerobic activated sludge system.

2002 ◽  
Vol 48 (1) ◽  
pp. 43-54 ◽  
Author(s):  
Shin Onda ◽  
Akira Hiraishi ◽  
Yoshitaka Matsuo ◽  
Susumu Takii
Keyword(s):  
Activated Sludge ◽  
Laboratory Scale ◽  
Activated Sludge System ◽  
Polyphosphate Accumulating Organisms

Removal and fate of estrogens in an anaerobic-anoxic-oxic activated sludge system

2011 ◽  
Vol 63 (1) ◽  
pp. 51-56 ◽  
Author(s):  
Y. M. Li ◽  
Q. L. Zeng ◽  
S. J. Yang
Keyword(s):  
Activated Sludge ◽  
Removal Efficiency ◽  
Laboratory Scale ◽  
Dominant Mechanism ◽  
Waste Sludge ◽  
Activated Sludge System ◽  
17Β Estradiol ◽  
Solid Phases ◽  
Final Effluent

Laboratory-scale experiments were conducted to investigate the removal and fate of estrogens 17β-estradiol (E2) and 17α-ethinylestradiol (EE2) in an anaerobic-anoxic-oxic (AAO) activated sludge system. Estrogen concentrations in the aqueous and solid phases in each reactor of AAO system were analyzed separately. E2 was not detected in the final effluent. The anaerobic, anoxic and oxic reactors accounted for 71%, 7% and 22% of the overall E2 removal, respectively. The overall EE2 removal efficiency was about 80%, and the anaerobic, anoxic and oxic reactors were responsible for 44%, 8% and 48% of the overall EE2 removal, respectively. In anaerobic unit, sorption was the dominant mechanism for the removal of E2 and EE2. While E2 was degraded in all the three units of the AAO system, EE2 was only degraded in the anoxic and aerobic units. Biodegradation is important for the fate of E2 compared to sorption. Of the total influent E2 in the AAO system, 99.99% was biodegraded and 0.01% remained in the waste sludge. Nevertheless, both sorption and biodegradation play important roles in the removal of EE2. Of the total influent EE2, 79.1% was degraded by activated sludge, 19.9% was discharged in the effluent and 1% remained in the waste sludge.

Biochemical Changes Associated with Luxury Phosphate Uptake in a Modified Phoredox Activated Sludge System

1983 ◽  
Vol 15 (3-4) ◽  
pp. 105-115 ◽  
Author(s):  
D J J Potgieter ◽  
B W Evans
Keyword(s):  
Activated Sludge ◽  
Biochemical Parameters ◽  
Phosphate Uptake ◽  
Biochemical Changes ◽  
Laboratory Scale ◽  
Anaerobic Conditions ◽  
Phosphate Release ◽  
Activated Sludge System

Several chemical and biochemical parameters were monitored for in a laboratory scale modified Phoredox activated sludge system fed with settled sewage. The influence of several substrates and pH on phosphate release under anaerobic conditions was investigated. The significance of some chemical and biochemical parameters in relation to luxury phosphate uptake is discussed and related to a concept of imbalanced provision of intermediates and other nutrients as the primary cause of enhanced phosphate uptake.

Oxidation Ditch

2018 ◽  
Author(s):  
Gede H Cahyana
Keyword(s):  
Activated Sludge ◽  
Special Form ◽  
Oxidation Ditch ◽  
End Point ◽  
Activated Sludge System

As a part of activated sludge system, oxidation ditch has a special form like a canal without end point. Rotor is used to diffuse oxygen from air to the water.

Parameters for Measuring the Activity and Viability of Activated Sludge

1974 ◽  
Vol 9 (1) ◽  
pp. 235-249 ◽  
Author(s):  
S.G. Nutt ◽  
K.L. Murphy
Keyword(s):  
Organic Carbon ◽  
Activated Sludge ◽  
Biological System ◽  
Analytical Methods ◽  
Heterogeneous System ◽  
Removal Rate ◽  
Bacterial Species ◽  
Atp Content ◽  
Culture Studies ◽  
Activated Sludge System

Abstract Conventional wastewater parameters are accepted as inadequate estimates of the condition of activated sludge but numerous other indices have been suggested as specific measurements of the activity and viability of the biomass. Literature in the related fields of microbiology and biochemistry were reviewed in order to select the most appropriate activity parameters for application to a heterogeneous biological material. Modified analytical methods were applied to a well-controlled biological system containing a single predominant bacterial species to evaluate the relative merit of each as an indicator of viability and activity. The potential of each parameter in a complex heterogeneous system was determined by monitoring each index in a bench activated sludge system. The predominant culture studies indicated that the ATP content of the biomass and the dehydrogenase activity were potential indicators of cell viability in a simple system. However, in the complex activated sludge system, only the ATP content showed significant correlation to the organic carbon removal rate.

TREATABILITY OF 2,4-D PRODUCTION WASTEWATERS

1994 ◽  
Vol 30 (3) ◽  
pp. 73-78 ◽  
Author(s):  
O. Tünay ◽  
S. Erden ◽  
D. Orhon ◽  
I. Kabdasli
Keyword(s):  
Hydrogen Peroxide ◽  
Activated Sludge ◽  
Partial Oxidation ◽  
Chloride Concentration ◽  
Chemical Oxidation ◽  
Cod Removal ◽  
Optimum Conditions ◽  
Organic Loading ◽  
Activated Sludge System ◽  
Biological Treatability

This study evaluates the characterization and treatability of 2,4-D production wastewaters. Wastewaters contain 20000-40000 mg/l COD, 17000-30000 mg/l chloride and pH is around 1.0. Chemical oxidation with hydrogen peroxide provided almost complete COD removal. The optimum conditions are 3:1 H2O2/COD oxidant dosage, 3000 mg/l Fe3+ as catalyst and pH 3. Partial oxidation at 0.5:1 H2O2//COD ratio is also effective providing 67% COD removal. A batch activated sludge system is used for biological treatability. Dilution is needed to maintain a tolerable chloride concentration which increases through COD removal. pH also increased during COD removal. 85% COD removal is obtained for the 50% dilution at an organic loading of 0.3 day‒1 on a COD basis. Completely and partially oxidized wastewaters are also treated in the activated sludge down to 30 mg/l BOD5.

Sign in / Sign up

Export Citation Format

Share Document