Water quality. Test for inhibition of oxygen consumption by activated sludge for carbonaceous and ammonium oxidation

2007 ◽  
Keyword(s):  
Water Quality ◽  
Oxygen Consumption ◽  
Activated Sludge ◽  
Ammonium Oxidation ◽  
Quality Test

Identification of inhibitory effects of industrial effluents on nitrification

2009 ◽  
Vol 59 (4) ◽  
pp. 797-803 ◽  
Author(s):  
A. Žgajnar Gotvajn ◽  
J. Zagorc-Končan
Keyword(s):  
Oxygen Consumption ◽  
Activated Sludge ◽  
Landfill Leachate ◽  
Industrial Effluents ◽  
Tannery Effluent ◽  
Ammonium Oxidation ◽  
Pharmaceutical Wastewater ◽  
Heterotrophic Microorganisms ◽  
Nitrification Process ◽  
The Impact

The aim of our work was to determine the extent of inhibition of oxygen consumption by activated sludge for carbonaceous and ammonium oxidation (ISO 8192 2007) for various wastewaters. We have selected several types of wastewaters different in their origin and composition: pharmaceutical wastewater, tannery wastewater and municipal landfill leachate. To confirm results of toxicity testing, additional ready biodegradability assessment test with measurement of oxygen consumption was accomplished to indicate the impact of effluents to nitrification process. Pharmaceutical wastewater was toxic to activated sludge, but it inhibited heterotrophic microorganisms much more than nitrifying ones. Biodegradability testing confirmed low impact to nitrification by high, non-suppressed oxygen consumption for nitrification process. Tannery effluent inhibited nitrification significantly (180 min EC50 was 57 vol.%), but it did not affect heterotrophic microorganisms. Landfill leachate was very toxic to heterotrophic microorganisms (180 min EC50 was 3 vol.%), while it inhibited nitrification less (180 min EC50 was 24 vol.%). Presented research confirmed that the investigated experimental method is a reliable one for detection of occurrence of substances inhibiting nitrification in different industrial effluents. With regular monitoring of inhibitory impact biological treatment process upsets could be avoided and treatment optimised.

Quantification of the kinetic differences between communities isolated from completely mixed activated sludge systems operated with or without a selector using a novel respirometric method

1994 ◽  
Vol 30 (11) ◽  
pp. 255-261 ◽  
Author(s):  
Barth F. Smets ◽  
Timothy G. Ellis ◽  
Stephanie Brau ◽  
Richard W. Sanders ◽  
C. P. Leslie Grady
Keyword(s):  
Oxygen Consumption ◽  
Activated Sludge ◽  
Physiological Changes ◽  
Biodegradation Kinetics ◽  
Substrate Removal ◽  
Biomass Yields ◽  
Selection For ◽  
Single Oxygen ◽  
Activated Sludge Systems

This study quantified the kinetic differences in microbial communities isolated from completely mixed activated sludge (CMAS) systems that were operated either with or without an aerobic selector preceding the main reactor. A new respirometric method was employed that allowed the determination of biodegradation kinetics from single oxygen consumption curves, thereby minimizing physiological changes to the examined communities during the assay. Results indicated that increased values for Ks and μmax for acetate, phenol, and 4-chlorophenol degradation were measured in the CMAS system operated with a selector. The biomass yields on acetate, phenol, and 4-chlorophenol were very similar in both systems. These findings indicate that the operation of CMAS systems with aerobic selectors may result in the selection for degrading populations with higher Ks and μmax values for both biogenic and xenobiotic organic compounds, and that substrate storage in the selector only partially contributes to increased substrate removal rates.

MODELING THE ORGANIC REMOVAL AND OXYGEN CONSUMPTION BY BIOFILMS IN AN OPEN-CHANNEL FLOW

1994 ◽  
Vol 30 (2) ◽  
pp. 53-61 ◽  
Author(s):  
Shiyu Li ◽  
Guang Hao Chen
Keyword(s):  
Water Quality ◽  
Oxygen Consumption ◽  
River Water ◽  
Channel Flow ◽  
Diffusion Layer ◽  
Open Channel ◽  
Open Channel Flow ◽  
River Water Quality ◽  
Monod Kinetics ◽  
Organic Removal

A mathematical model is proposed to predict the removal of dissolved organic substances and the consumption of dissolved oxygen by attached biofilms in an open-channel flow. The model combines the biofilm equations with the conventional Streeter–Phelps type equations of river water quality by considering the mass transfer of organics and oxygen in the river water through the diffusion layer into the biofilm. It is assumed that the diffusion and reaction within the biofilm are of steady-state, and follow Monod kinetics. The model is solved numerically with a trial-and-error method. The simulation results of the model for an ideal case of river flow and biofilm show that the organic removal rate and oxygen consumption rate caused by the biofilm are greater than that by suspended biomass. The effects of diffusion layer thickness, flow velocity, and biofilm thickness on the change of river water quality are discussed.

Changes in waste stabilisation pond performance resulting from the retrofit of activated sludge treatment upstream: part I – water quality issues

2005 ◽  
Vol 51 (12) ◽  
pp. 11-16 ◽  
Author(s):  
N.J. Cromar ◽  
D.G. Sweeney ◽  
M.J. O'Brien ◽  
H.J. Fallowfield
Keyword(s):  
Water Quality ◽  
Dissolved Oxygen ◽  
Activated Sludge ◽  
Algal Biomass ◽  
Inorganic Nitrogen ◽  
Treatment Plant ◽  
South Australia ◽  
N:P Ratio ◽  
Waste Stabilisation Ponds ◽  
Trickling Filters

This paper describes changes in effluent quality occurring before and after an upgrade to the Bolivar Wastewater Treatment Plant in South Australia. Trickling filters (TF) were replaced with an activated sludge (AS) plant, prior to tertiary treatment using waste stabilisation ponds (WSPs). The water quality in the WSPs following the upgrade was significantly improved. Reductions in total and soluble BOD, COD, TKN, suspended solids and organic nitrogen were recorded and the predominant form of inorganic nitrogen changed from NH4-N to NO2/NO3-N. The reduction in ammonium and potentially toxic free ammonia removed a control upon the growth of zooplankton, which may have contributed to decreases in algal biomass in the final ponds and consequently lower dissolved oxygen. Additionally, changes in inorganic nitrogen speciation contributed to a slightly elevated pH which reduced numbers of faecal coliforms in WSPs. The AS pretreated influent recorded significantly lower inorganic molar N:P ratio (10–4:1) compared to those fed with TF effluent (17–13:1). Algae within the WSPs may now be nitrogen limited, a condition which may favour the growth of nitrogen-fixing cyanobacteria. The decrease in algal biomass and in dissolved oxygen levels may enhance sedimentary denitrification, further driving the system towards nitrogen limitation.

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