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Balancing effluent quality, greenhouse gas emissions and operational cost - developing dynamical models for intergrated benchmarking of wastewater treatment plants

Arnell, Magnus LU and Jeppsson, Ulf LU (2012) In Vatten: tidskrift för vattenvård /Journal of Water Management and research 68(4). p.295-302
Abstract
The scope for wastewater treatment plants (WWTPs) widens to consider not only water quality and cost, but also energy efficiency and greenhouse gas (GHG) emissions. The on-going research project, “Development and dynamic analysis of operational strategies for enhanced energy efficiency of wastewater treatment systems” aims to develop a tool for integrated evaluation of energy efficiency and greenhouse gas (GHG) emissions with effluent quality and operational costs. The tool will build on the comprehensive Benchmark Simulation Model no. 2. It will be extended with models for: i) production and emission of CO2, N2O and CH4 and ii) calculation of energy consumption and production at the plant. Here, a first attempt is presented together with... (More)
The scope for wastewater treatment plants (WWTPs) widens to consider not only water quality and cost, but also energy efficiency and greenhouse gas (GHG) emissions. The on-going research project, “Development and dynamic analysis of operational strategies for enhanced energy efficiency of wastewater treatment systems” aims to develop a tool for integrated evaluation of energy efficiency and greenhouse gas (GHG) emissions with effluent quality and operational costs. The tool will build on the comprehensive Benchmark Simulation Model no. 2. It will be extended with models for: i) production and emission of CO2, N2O and CH4 and ii) calculation of energy consumption and production at the plant. Here, a first attempt is presented together with a case where different set-points of dissolved oxygen, DO, in the aeration-tanks are simulated. The simulation results show that lowering the DO set-point from 2 mg l–1 to 1 mg l–1 reduces the CO2-emissions by 570 kg d–1, a reduction from 30,500 kg CO2 d–1 emitted from the plant at 2 mg DO l–1. However, at the same time this slightly increases the effluent discharge. Moreover, due to increased nitrite accumulation in the aeration tank, the N2O emissions increase by 12,500 kg carbon dioxide equivalents, CO2e d–1, which dramatically exceeds the reduction due to lowered power generation. Accordingly the total GHG-emissions are reduced by an increase of the DO set-point to 3 mg l–1, but the reduction is insignificant and the increased operational cost disproportional to the improvements in the emissions. The conclusion is that, to meet multi-objective goals, integrated benchmarking of the three criteria is essential. (Less)
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author
organization
publishing date
type
Contribution to journal
publication status
published
subject
in
Vatten: tidskrift för vattenvård /Journal of Water Management and research
volume
68
issue
4
pages
295 - 302
publisher
Föreningen Vatten
ISSN
0042-2886
language
Swedish
LU publication?
yes
id
72d64523-8444-418d-a55d-1755f84d05ed (old id 4406375)
alternative location
http://www.tidskriftenvatten.se/mag/tidskriftenvatten.se/dircode/docs/48_article_4605.pdf
date added to LUP
2014-04-25 10:16:50
date last changed
2016-04-16 06:11:06
@misc{72d64523-8444-418d-a55d-1755f84d05ed,
  abstract     = {The scope for wastewater treatment plants (WWTPs) widens to consider not only water quality and cost, but also energy efficiency and greenhouse gas (GHG) emissions. The on-going research project, “Development and dynamic analysis of operational strategies for enhanced energy efficiency of wastewater treatment systems” aims to develop a tool for integrated evaluation of energy efficiency and greenhouse gas (GHG) emissions with effluent quality and operational costs. The tool will build on the comprehensive Benchmark Simulation Model no. 2. It will be extended with models for: i) production and emission of CO2, N2O and CH4 and ii) calculation of energy consumption and production at the plant. Here, a first attempt is presented together with a case where different set-points of dissolved oxygen, DO, in the aeration-tanks are simulated. The simulation results show that lowering the DO set-point from 2 mg l–1 to 1 mg l–1 reduces the CO2-emissions by 570 kg d–1, a reduction from 30,500 kg CO2 d–1 emitted from the plant at 2 mg DO l–1. However, at the same time this slightly increases the effluent discharge. Moreover, due to increased nitrite accumulation in the aeration tank, the N2O emissions increase by 12,500 kg carbon dioxide equivalents, CO2e d–1, which dramatically exceeds the reduction due to lowered power generation. Accordingly the total GHG-emissions are reduced by an increase of the DO set-point to 3 mg l–1, but the reduction is insignificant and the increased operational cost disproportional to the improvements in the emissions. The conclusion is that, to meet multi-objective goals, integrated benchmarking of the three criteria is essential.},
  author       = {Arnell, Magnus and Jeppsson, Ulf},
  issn         = {0042-2886},
  language     = {swe},
  number       = {4},
  pages        = {295--302},
  publisher    = {ARRAY(0xaa4bd98)},
  series       = {Vatten: tidskrift för vattenvård /Journal of Water Management and research},
  title        = {Balancing effluent quality, greenhouse gas emissions and operational cost - developing dynamical models for intergrated benchmarking of wastewater treatment plants},
  volume       = {68},
  year         = {2012},
}