Dynamic Modeling of Diffused Aeration Requirements for High-Rate Plug-Flow and Step-Feed Activated Sludge Systems

Abstract The implementation of carbon capture technologies such as high-rate activated sludge (HRAS) systems are gaining interests in water resource and recovery facilities (WRRFs) to minimize carbon oxidation and maximize organic carbon recovery and methane potential through biosorption of biodegradable organics into the biomass. Existing activated sludge models were developed to describe chemical oxygen demand (COD) removal in activated sludge systems operating at long solids retention times (SRT) (i.e. 3 days or longer) and fail to simulate the biological reactions at low SRT systems. A new model is developed to describe colloidal material removal and extracellular polymeric substance (EPS) generation, flocculation, and intracellular storage with the objective of extending the range of whole plant models to very short SRT systems. In this study, the model is tested against A-stage (adsorption) pilot reactor performance data and proved to match the COD and colloids removal at low SRT. The model was also tested on longer SRT systems where effluents do not contain much residual colloids, and digestion where colloids from decay processes are present.

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Effect of feed mode and Food Microorganisms ratio on efficiency of Plug-Flow activated sludge systems with plug-flow in removal of organic matter, phosphor PO4 and nitrat NO3

Journal of Environmental Studies ◽

10.21608/jesj.2013.194901 ◽

2013 ◽

Vol 12 (1) ◽

pp. 11-17

Author(s):

Kussay Alahmady ◽

Waleed Alabdraba ◽

Ahmed Aldulaimy

Keyword(s):

Organic Matter ◽

Activated Sludge ◽

Plug Flow ◽

Feed Mode ◽

Activated Sludge Systems

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The effect of reactor configuration and operational mode on Microthrix parvicella bulking and foaming in nutrient removal activated sludge systems

Water Science & Technology ◽

10.2166/wst.2002.0457 ◽

2002 ◽

Vol 46 (1-2) ◽

pp. 61-64 ◽

Cited By ~ 7

Author(s):

C. Noutsopoulos ◽

D. Mamais ◽

A.D. Andreadakis

Keyword(s):

Activated Sludge ◽

Nutrient Removal ◽

Plug Flow ◽

Selective Advantage ◽

Operational Mode ◽

Intermittent Aeration ◽

Reactor Configuration ◽

Microthrix Parvicella ◽

Activated Sludge Systems ◽

Removal System

Three bench-scale nutrient removal activated sludge units were used to examine the effect of the reactor configuration and the intermittent aeration mode on the growth of Microthrix parvicella. According to the results, the plug flow configuration seems to achieve satisfactory Microthrix parvicella control. The imposed concentration gradient for both RBCOD and SBCOD creates a selective advantage for the floc forming bacteria throughout the system (both the anoxic and oxic zones) and limits Microthrix parvicella growth. In terms of the operational mode, the intermittent aeration CSTR nutrient removal system promotes the growth of M.parvicella and deteriorates the settling characteristics of the activated sludge.

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