A NOVEL TREATMENT SYSTEM TO REMOVE PHOSPHORUS FROM LIQUID MANURE

作者：Church C D^*; Hristov A N; Bryant R B; Kleinman P J A; Fishel S K

来源：Applied Engineering in Agriculture, 2016, 32(1): 103-112.

DOI：10.13031/aea.32.10999

• Chemical precipitation
• Manure
• Nitrogen
• Phosphorus
• Solid separation
• Treatment systems

Lowering the phosphorus (P) content of animal manure is one approach of addressing concerns over surplus P accumulation in soils resulting from land application of animal manure. We sought to develop a treatment system for liquid manures that conserves manure nitrogen (N) while removing most of the manure P. Initial evaluation of a treatment system involving manure 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 three-stage system with iterative solid removal and acid salt (ferric sulfate - Fe-2(SO4)(3)) sorption of dissolved P: (1) removal of bulk and intermediate sized solids (> 25 mu m); (2) chemical treatment to convert dissolved P; and (3) final removal of fine solids and chemically sorbed P. When tested on manure slurries from 150 and 2700 cow dairies, 96% to 99% aqua regia extractable P was removed along with 92% to 94% of the solids, resulting in liquid manure filtrates with N: P ratios greater than 19:1. While costs of treatment were roughly $38 kg(-1) P removed, equivalent to $750 cow(-1) yr(-1), we anticipate that refinement of the process and beneficial uses of the solid materials (bedding, compost, etc.) will improve cost-efficacy considerably.

• 出版日期2016