Agricultural and Biosystems Engineering Publications

Campus Units

Agricultural and Biosystems Engineering, Animal Science

Document Type

Article

Publication Version

Published Version

Publication Date

2009

Journal or Book Title

Applied Engineering in Agriculture

Volume

25

Issue

1

First Page

103

Last Page

108

DOI

10.13031/2013.25427

Abstract

The goal of this project was to develop a system that identified magnesium demand for struvite formation by monitoring conductivity changes during continuous injection of magnesium chloride in several swine manure slurries. The conductivity of six manure slurries was monitored to identify the response due to magnesium chloride injection (MgCl2) and struvite precipitation. Struvite precipitation is a technically feasible treatment method for phosphorus removal and recovery from manure slurries (Burns et al., 2003; Bowers and Westerman, 2005a). Swine manure slurries often require the addition of magnesium (Mg2+) to force struvite precipitation. The quantity of Mg2+ required for maximized phosphorus removal can be determined through laboratory tests. Optimized struvite precipitation in a field setting requires a real-time method to determine Mg2+ addition rates during a land application event. This article discusses the requirements of an automated control system which monitors and controls the injection of Mg2+ to force struvite precipitation, accounting for real-time variations of magnesium demand. Theoretical predictions and pure solution tests provided information capable of determining the magnesium demand for struvite precipitations. After testing six different manures in triplicate, the conductivity responses did not follow theoretical predictions and failed to provide any indication of optimum magnesium injection rates for phosphorus removal.

Comments

This article is from Applied Engineering in Agriculture, 25, no. 1 (2009): 103–108.

Access

Open

Copyright Owner

American Society of Agricultural and Biological Engineers

Language

en

File Format

application/pdf

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