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Updated: Jul 3, 2026
07:59
Estimating Sediment Denitrification Rates Using Cores and N2O Microsensors
Published on: December 6, 2018
Denitrification with carbon addition--kinetic considerations.
P Dold1, I Takács, Y Mokhayeri
1EnviroSim Associates Ltd., Flamborough, Ontario, Canada. dold@envirosim.com
Summary
Wastewater treatment plants using methanol for denitrification face challenges in winter due to temperature effects on microbes. This study investigated methanol-utilizing bacteria kinetics and alternative carbon sources to improve nitrogen removal efficiency.
Area of Science:
- Environmental microbiology
- Wastewater engineering
- Biogeochemical cycles
Background:
- The Blue Plains Advanced Wastewater Treatment Plant utilizes methanol as an external carbon source for postdenitrification to reduce effluent total nitrogen.
- Lower temperatures and higher flows in winter negatively impact the kinetic behavior of methanol-utilizing heterotrophs, complicating nitrogen removal.
- Understanding microbial kinetics is crucial for optimizing nutrient removal in advanced wastewater treatment.
Purpose of the Study:
- To determine the maximum specific growth rate (Mu(METH)) of methanol-utilizing heterotrophs in postdenitrification sludge.
- To investigate the temperature dependency of the growth rate of these microorganisms.
- To evaluate the effectiveness of alternative carbon substrates (ethanol, acetate, sugar) compared to methanol.
Main Methods:
- Experimental batch tests were performed on postdenitrification sludge from the Blue Plains facility.
- Key parameters measured included maximum specific growth rate and temperature-dependent growth kinetics.
- Limited tests were also conducted on sludge from two additional treatment plants utilizing methanol.
Main Results:
- The study quantified the maximum specific growth rate of methanol-utilizing heterotrophs.
- The temperature dependency of microbial growth rates was characterized, highlighting winter performance challenges.
- Preliminary data on the efficacy of alternative substrates was gathered.
Conclusions:
- Methanol-utilizing heterotroph kinetics are temperature-sensitive, impacting winter denitrification efficiency.
- Further research into alternative carbon sources may offer solutions for optimizing nitrogen removal under varying conditions.
- Optimizing external carbon source strategy is vital for consistent low effluent nitrogen concentrations.
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