Sustainably Overcoming Hindrance to Struvite Recovery from Anaerobically Digested Dairy Manure

EPA Grant Number: SU836013
Title: Sustainably Overcoming Hindrance to Struvite Recovery from Anaerobically Digested Dairy Manure
Investigators: Tao, Wendong , Moran, Sharon
Current Investigators: Tao, Wendong , Arnold, Christopher , Wright, David , Mayer, Douglas , Leon, Eileen , Agyeman, Fred , Wen, Jianfeng , Martin, Lee , Moran, Sharon , Shi, Shun , Xu, Wenjie
Institution: The State University of New York
EPA Project Officer: Hahn, Intaek
Phase: I
Project Period: August 15, 2011 through August 14, 2012
Project Amount: $15,000
RFA: P3 Awards: A National Student Design Competition for Sustainability Focusing on People, Prosperity and the Planet (2011) RFA Text |  Recipients Lists
Research Category: Pollution Prevention/Sustainable Development , P3 Challenge Area - Sustainable and Healthy Communities , P3 Challenge Area - Chemical Safety , P3 Awards , Sustainable and Healthy Communities


This project will explore sustainable approaches to overcoming the hindrance of high Ca2+ concentration and ionic strength to struvite recovery from filtrate of anaerobically digested dairy manure.


Anaerobically digested dairy manure has high concentrations of phosphate, ammonium, and magnesium, which could be recovered at a higher pH (8.5-9.5) as struvite, MgNH4PO4∙6H2O. However, high ionic strength and calcium content interferes with struvite recovery from digested dairy manure. We propose to: 1) use furnace slag to raise pH for calcium precipitation and struvite recovery; 2) make proper use of dilution to minimize ionic strength and maximize phosphate activity for efficient struvite precipitation; 3) determine velocity gradient for efficient recovery of struvite in a batch crystallizer driven by an air-lift pump; and 4) assess the market share of struvite production with digested dairy manure.

Expected Results:

1) Struvite is a slow-release compound fertilizer. Struvite recovery from digested dairy manure could remove phosphate and ammonium while providing revenues for farmers. 2) Utilization of furnace slag and dilution will improve sustainability of struvite recovery. The optimum type and particle size of furnace slag will be identified based on efficient pH elevation and minimum PO43- adsorption. The optimum dilution ratio will be identified based on total mass of struvite recoverable. 3) Operational parameters will be optimized for the batch struvite crystallizer. 4) The market share of manure-based struvite among other manure products will be evaluated for New York State.

Publications and Presentations:

Publications have been submitted on this project: View all 8 publications for this project

Journal Articles:

Journal Articles have been submitted on this project: View all 2 journal articles for this project

Supplemental Keywords:

Bio-based feedstock, phosphorus recovery, waste to value

Relevant Websites:

Phase 2 Abstract

Progress and Final Reports:

  • Final Report
  • P3 Phase II:

    Struvite Recovery from Anaerobically Digested Dairy Manure  | 2013 Progress Report  | 2014 Progress Report  | Final Report