Insights from metagenomic, metatranscriptomic, and molecular ecological network analyses into the effects of chromium nanoparticles on 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.

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Parameters for Measuring the Activity and Viability of Activated Sludge

Water Quality Research Journal ◽

10.2166/wqrj.1974.022 ◽

1974 ◽

Vol 9 (1) ◽

pp. 235-249 ◽

Cited By ~ 1

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.

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TREATABILITY OF 2,4-D PRODUCTION WASTEWATERS

Water Science & Technology ◽

10.2166/wst.1994.0067 ◽

1994 ◽

Vol 30 (3) ◽

pp. 73-78 ◽

Cited By ~ 3

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.

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