Comparison of the Characteristics and Separation Efficiency of Different Mink and Pig Manures

Abstract

Abstract. Three pig and two mink manures were pretreated with polymers and with iron (mink only) before filtration. Solid-liquid separation was conducted using a full-scale separation facility. Piglet manure was more difficult to separate than sow and mink manures due to the small particle size, high organic matter content, and high particle charge. For mink manure, the poorest separation was also observed in the manure with high particle charge, high small particle concentration, and high dry matter content. The dry matter content in the liquid fraction was 1.5% to 2.75% for pig manure and 0.6% to 1.1% for mink manure at optimum polymer dosage. The particulate phosphorus in the liquid fraction correlated well with the dry matter content and could be reduced by adding polymer. At optimum polymer dosages, the total phosphorous in the liquid fraction was 305 to 800 ppm for pig manure and 260 to 285 ppm for mink manure. Iron addition reduced the concentration of dissolved inorganic phosphorus in the mink manure liquid fraction but only slightly affected the removal of particulate phosphorus.