Skip to main content

Energy and Greenhouse Gas Implications for Removal of Micro-Constituents in Wastewater

Buy Article:

$17.50 plus tax (Refund Policy)

Or sign up for a free trial

Abstract:

Enforcement of increasingly stringent effluent limits, and application of more sophisticated treatment processes for reduction of micro-constituents (MCs), increases the energy consumed in municipal wastewater treatment processes. Some MCs can be reduced or eliminated effectively when secondary processes are operated to fully nitrify ammonia. Upgrading non-nitrifying treatment facilities to full nitrification would result in an increase in energy consumption of approximately 300 to 500 kWh/1000 m3 treated. Other MCs, such as pesticides, and some pharmaceuticals are relatively resistant to biological oxidation. Membrane processes such as reverse osmosis (RO) or nanofiltration (NF) and advanced oxidation processes (AOP), such as UV/ozone or UV/hydrogen peroxide, have also been shown as effective for many MCs. The combined energy consumption for an AOP consisting of UV/ozone would total between 220 and 420 kWh/1000 m3 treated. Inclusion of RO may nearly triple the plant energy consumption.

The increased electricity needed to reduce the micro-constituents in wastewater effluents results in higher emissions of greenhouse gases (principally carbon dioxide) from electricity generating stations. The emission rate of GHGs from electricity generation depends on the mix of generation types, including fossil-fuel thermal, nuclear, hydro-electric, wind, geothermal and other types, employed in different geographical area in North America. It is therefore possible to calculate the increase in electricity-related GHG emissions due to use of more advanced energyintensive processes for reduction of MC concentrations in municipal effluents. In environmental stewardship, efforts should be focused on minimizing overall environmental impact. A rush to invest in the high costs of capital improvements, resulting from a decision to impose ultrastringent levels of treatment on the municipal effluents, may not be the wisest path until the impact on the total environment and human health is understood.

Keywords: Wastewater; energy; greenhouse gas emissions; micro-constituents

Document Type: Research Article

DOI: https://doi.org/10.2175/193864709793900889

Publication date: 2009-01-01

More about this publication?
  • Proceedings of the Water Environment Federation is an archive of papers published in the proceedings of the annual Water Environment Federation® Technical Exhibition and Conference (WEFTEC® ) and specialty conferences held since the year 2000. These proceedings are not peer reviewed.

    WEF Members: Sign in (right panel) with your IngentaConnect user name and password to receive complimentary access.
  • Subscribe to this Title
  • Membership Information
  • About WEF Proceedings
  • WEFTEC Conference Information
  • Ingenta Connect is not responsible for the content or availability of external websites
  • Access Key
  • Free ContentFree content
  • Partial Free ContentPartial Free content
  • New ContentNew content
  • Open Access ContentOpen access content
  • Partial Open Access ContentPartial Open access content
  • Subscribed ContentSubscribed content
  • Partial Subscribed ContentPartial Subscribed content
  • Free Trial ContentFree trial content
Cookie Policy
X
Cookie Policy
Ingenta Connect website makes use of cookies so as to keep track of data that you have filled in. I am Happy with this Find out more