Identifying and Overcoming Hindrance to Struvite Recovery from Filtrate of Anaerobically Digested Dairy Manure
Struvite recovery has been demonstrated at pilot and full scales for phosphorus removal from municipal wastewater, swine wastewater, and industrial wastewater at elevated pH and high Mg2+:NH4 +:PO4 3− ratios. Anaerobically digested dairy manure is rich in magnesium, ammonium, and phosphate. However, struvite recovery from anaerobically digested dairy manure has been challenging. This study examined struvite recovery from the filtrate of anaerobically digested dairy manure, which was separated from manure solids in a pebble filter – vertical flow subsurface wetland series. Unlike mechanically separated dairy manure liquid, the filtrate had little particulate phosphorus and magnesium and substantial particulate calcium. Water extraction and acid extraction increased Ca2+ by 112% and 28% respectively. Batch precipitation tests showed linear decreases of orthophosphate concentration reduction and precipitate mass as more real manure filtrate was mixed with artificial manure filtrate, indicating hindrance to struvite precipitation from the manure filtrate. Energy dispersive X-ray analysis confirmed that the precipitates from 100% artificial manure filtrate were struvite. The hindrance could be attributed to high ionic strength, Ca2+ concentration, Ca2+:Mg2+ ratio, alkalinity, or Cl−. It was found that the manure filtrate could be pretreated via chemical precipitation at pH 9–10 for Ca removal while retaining Mg2+ and PO4 3−. The Ca precipitates were identified by energy dispersive X–ray analysis to be likely CaCO3.
No Reference information available - sign in for access.
No Citation information available - sign in for access.
No Supplementary Data.
Document Type: Research Article
Publication date: 2011-01-01
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 These proceedings are not peer reviewed. A subscription to the Proceedings of the Water Environment Federation includes access to most papers presented at the annual WEF Technical Exhibition and Conference (WEFTEC) and other conferences held since 2000. Subscription access begins 12 months after the event and is valid for 12 months from month of purchase. A subscription to the Proceedings of the Water Environment Federation is included in Water Environment Federation (WEF) membership.
WEF Members: Sign in (right panel) with your IngentaConnect user name and password to receive complimentary access. Access begins 12 months after the conference or event
- Subscribe to this Title
- Membership Information
- About WEF Proceedings
- WEFTEC Conference Information
- Learn about the many other WEF member benefits and join today
- Ingenta Connect is not responsible for the content or availability of external websites