Aerated denitrification in full-scale activated sludge facilities

1996 ◽  
Vol 34 (1-2) ◽  
pp. 487-491 ◽  
Author(s):  
Mervyn C. Goronszy ◽  
Gunnar Demoulin ◽  
Mark Newland
Keyword(s):  
Activated Sludge ◽  
Plug Flow ◽  
Domestic Wastewater ◽  
Initial Reaction ◽  
Reaction Volume ◽  
Variable Volume ◽  
Domestic Wastewater Treatment ◽  
Mode Of Operation ◽  
Nitrogen Concentrations ◽  
Low Nitrogen

The practice of manipulating activated sludge reaction environments to obtain maximum nitrogen removal has been optimized using cyclic activated sludge technology. In its simplest form, the sequences of fill aeration, settle and decant are consecutively and continuously operated in a compartmented reactor in which an initial reaction volume performs the function of a biological selector with biomass from a final reaction volume. The technology incorporates the principles of biological accumulation - regeneration processing in which a variable volume plug-flow reaction environment precedes a variable volume complete-mix reaction environment. Both reactor volumes are typically in continuous fluid communication. This configuration and mode of operation allows removal performance in domestic wastewater treatment applications to meet less than 5 mg/L total nitrogen discharge limits. Low nitrogen concentrations are obtained using modified aeration sequences only in which the bulk phase dissolved oxygen concentration is typically less than 2 mg/L in a ramped profile beginning at zero. By that means a simultaneous or co-current nitrification-denitrification mechanism is obtained. Track run data illustrate the performance obtained in domestic applications.

Aerated denitrification in full-scale activated sludge facilities

1997 ◽  
Vol 35 (10) ◽  
pp. 103-110 ◽  
Author(s):  
Mervyn C. Goronszy ◽  
Gunnar Demoulin ◽  
Mark Newland
Keyword(s):  
Activated Sludge ◽  
Nitrogen Removal ◽  
Plug Flow ◽  
Domestic Wastewater ◽  
Initial Reaction ◽  
Biological Phosphorus Removal ◽  
Reaction Volume ◽  
Variable Volume ◽  
Mode Of Operation ◽  
Nitrogen Concentrations

The practice of manipulating activated sludge reaction environments to obtain maximum nitrogen removal has been optimized using cyclic activated sludge technology. In its simplest form, the sequences of fill aeration, settle and decant are consecutively and continuously operated in a compartmented variable volume reactor in which an initial reaction volume performs the function of a biological selector using biomass from a final reaction volume. The technology incorporates the principles of biological accumulation-regeneration processing in which a variable volume plug-flow reaction environment precedes a variable volume complete-mix reaction environment, both of which are typically in continuous fluid communication. This configuration and mode of operation allows removal performance in domestic wastewater treatment applications to meet less than 5 mgL−1 total nitrogen discharge limits. Low nitrogen concentrations are obtained using modified aeration sequences only in which the bulk phase sequenced dissolved oxygen concentration is typically less than 2 mgL−1 in a ramped profile beginning at zero. By that means a simultaneous or co-current nitrification-denitrification mechanism is obtained. Cycle manipulation required to maintain high nitrogen removal performance during less than design loadings is addressed. In-basin monitoring illustrates nitrogen removal performance obtained in domestic wastewater applications. This mode of operation is also important to the efficacy of biological phosphorus removal where available readily degradable soluble substrate is near to limiting.

Effect of blending landfill leachate with activated sludge on the domestic wastewater treatment process

2019 ◽  
Vol 5 (2) ◽  
pp. 268-276 ◽  
Author(s):  
Min Zheng ◽  
Siqi Li ◽  
Qian Dong ◽  
Xia Huang ◽  
Yanchen Liu
Keyword(s):  
Wastewater Treatment ◽  
Activated Sludge ◽  
Landfill Leachate ◽  
Treatment Process ◽  
Domestic Wastewater ◽  
Free Ammonia ◽  
Wastewater Treatment Process ◽  
Domestic Wastewater Treatment ◽  
High Level ◽  
Ammonia Exposure

A sludge contact is proposed to form high-level free ammonia exposure for co-treatment of landfill leachate with domestic wastewater.

Proliferation of glycogen accumulating organisms induced by Fe(III) dosing in a domestic wastewater treatment plant

2006 ◽  
Vol 54 (1) ◽  
pp. 101-109 ◽  
Author(s):  
A. Jobbágy ◽  
B. Literáthy ◽  
M.-T. Wong ◽  
G. Tardy ◽  
W.-T. Liu
Keyword(s):  
Wastewater Treatment ◽  
Activated Sludge ◽  
Wastewater Treatment Plant ◽  
Phosphorus Deficiency ◽  
Treatment Plant ◽  
Domestic Wastewater ◽  
Chemical Precipitation ◽  
Microbiological Analysis ◽  
Domestic Wastewater Treatment ◽  
Polyphosphate Accumulating Organisms

To meet the effluent requirements given for the sensitive receiving body, the Southpest Wastewater Treatment Plant of Budapest, Hungary uses a combined activated sludge-biofilter system with chemical precipitation for P removal. Causes of the proliferation of glycogen accumulating organisms (GAOs) observed in the unaerated/oxic activated sludge unit of this system were investigated both in full-scale and in lab-scale experiments combined with a detailed analysis of the microbial communities. Concentration profile measurements throughout the 8-stage activated sludge unit indicated anaerobic conditions in the first two unaerated reactors and low orthophosphate level (<1 mg l−1) in all of the stages that could not be attributed to the influent quality, but to Fe (III)-dosing to the returned activated sludge. Microbiological analysis revealed the presence of GAOs from the GB group in the Gammaproteobacteria and occasionally tetrad-forming organisms from Actinobacteria, and the absence of Rhodocyclus-related polyphosphate accumulating organisms (PAOs) in the activated sludge samples. Comparative lab-scale studies carried out in two identically arranged UCT-systems with staged anoxic reactors also confirmed that Fe (III)-dosing may result in phosphorus deficiency of the microbial niche, leading to the suppression of growth and EBPR activity of PAOs and to the proliferation of GAOs.

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