Microalgae Growth For Nutrient Recovery From Sludge Liquor and Production of Renewable Bioenergy

$17.50 plus tax (Refund Policy)

Buy Article:

Abstract:

Proof-of-concept has been demonstrated for a process that will utilize nutrients from sludge liquor, natural light, and CO2 from biogas to grow microalgae at wastewater treatment plants. The microalgae will remove nitrogen and phosphorus from the sludge liquor, significantly reducing the impact of returning side-streams to the head of the treatment plant. The produced algae will be harvested and fed to existing anaerobic digesters for co-digestion with wastewater sludge for increased production of renewable bioenergy.

Dewatering of anaerobically digested sludge in centrifuges produces reject water that often is black, contains a lot of very fine solids particles, and has extremely low transmittance of light. Pre-treatment of the reject water is necessary to make it a suitable substrate for growth of algae. A procedure was developed that improved light transmittance for reject water from the FREVAR, Norway, wastewater treatment plant from 0.1 % T to 77 % T (670 nm, 1 cm path).

Chlorella sp. microalgae were found to be suitable for growth in pre-treated reject water that was undiluted. Typical nitrogen removal was 80-90 g N/kg TSS of produced microalgae.

The Chlorella sp. microalgae were successfully harvested by chemically assisted flocculation followed by straining through a 33 μm sieve cloth. Up to 99 % recovery of the produced algae was achieved. Harvested algae were anaerobically co-digested with wastewater sludge. The specific methane gas production (mL CH4/g VS fed) for the algae varied from 74 to 90 % of the specific methane gas production for the wastewater sludge, depending on digester temperature and pre-treatment of the algae biomass.
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 These proceedings are not peer reviewed.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
  • ingentaconnect is not responsible for the content or availability of external websites

Tools

Favourites

Share Content

Access Key

Free Content
Free content
New Content
New content
Open Access Content
Open access content
Subscribed Content
Subscribed content
Free Trial Content
Free trial content
Cookie Policy
X
Cookie Policy
ingentaconnect 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