304-4 A NOVEL Treatment System to Remove Phosphorus from Liquid Wastes.
Poster Number 843
See more from this Division: SSSA Division: Nutrient Management & Soil & Plant AnalysisSee more from this Session: Manure/Organic Nutrient Source Management
Tuesday, November 4, 2014
Long Beach Convention Center, Exhibit Hall ABC
Lowering the total phosphorus (P) content of animal manures is one means of addressing concerns over excessive P addition to soils and P runoff following land application of animal manure. We sought to develop a treatment system for liquid manures that conserves the manure nitrogen (N) content while removing most of the manure P content. Initial evaluation of a treatment system involving manure liquid-solid separation and precipitation of dissolved P with an alkaline salt (Ca(OH)2) resulted in poor liquid/solid separation and poor dissolved P removal and created conditions promoting ammonia-N (NH3-N) volatilization. As a result, we developed a four stage system with iterative solid removal and acid salt (ferric sulfate – Fe2(SO4)3) precipitation of dissolved P: (1) removal of bulk solids; (2) removal of intermediate sized solids (>25 μm); (3) chemical treatment to convert dissolved P; (4) final removal of fine solids and chemically precipitated P. When tested on manure slurries from 150 and 2700 cow dairies, 96-99% total P was removed, resulting in a liquid manure filtrate with approximately 400:1 N:P ratio. While costs of treatment were roughly $38 kg-1 P removed, equivalent to $750 cow-1yr-1, we anticipate that refinement of the process and beneficial uses of the solid materials (bedding, compost, etc.) will improve cost-efficacy considerably.
See more from this Division: SSSA Division: Nutrient Management & Soil & Plant AnalysisSee more from this Session: Manure/Organic Nutrient Source Management