Potential of Solid-Liquid Separation of Swine Wastes for Methane Production

Abstract

ABSTRACT THE feasibility of using a vibrating screen separator to concentrate flushed swine waste for use in an anaerobic digestor system is evaluated on the basis of the properties of the solid separate. Four flowrates (37.5, 75, 112.5, and 150 L/min) and five screen mesh sizes (8, 18, 30, 60, and 150) were combined for trial runs on a 45.7 cm diameter Sweco vibrating separator. The waste was obtained from a finishing house flushing waste disposal system. Analysis of the flushed waste, and the liquid and solid separate included total solids (TS), volatile solids (VS), fixed solids (FS), total carbon (TC), chemical oxygen demand (COD), total Kjeldahl nitrogen (TKN-N), ammonia (NH3-N), total (TP-P) and ortho-phosphate (OP-P). Mass balances calculated from the results of the different combinations of flowrate and screen size in the continuous flow system showed that the total amount of organic material (measured as volatile solids) retained on the screens varied from 17 to 70%, TKN-N varied from 2.5 to 50%, NH3-N from 3 to 47%, and ortho-phosphate from 9 to 57% with increasing screen mesh and flowrate.