Submitted to: Agronomy Abstracts
Publication Type: Abstract Only
Publication Acceptance Date: 10/21/2001
Publication Date: N/A
Technical Abstract: Manure nutrients in excess of land utilization, ammonia emissions and pathogens are often an environmental concern in confined animal production. We evaluated an alternative system for treatment of liquid swine manure where the lagoon is omitted. In this multistage system, solids and liquid are separated with polyacrylamide (PAM), followed by biological N removal using nitrification/denitrification and P extraction through a lime precipitation process. The pilot system was evaluated for 1 yr at NCSU Waste Management Center. Inflow avg. nutrient concentration (mg/L) was TKN=555; total P=245; organic N=353; and organic P=215. Total suspended solids (SS) = 5900 mg/L; Volatile SS = 4800 mg/L; and BOD = 2600 mg/L. For solids separation, we used a Deskins module with an in-line PAM flocculator and a quick-drying sand filter bed. PAM treatment reduced 85% of BOD; 98% of TSS and VSS; 89% of org. N; and 93% of org. P. A Biogreen module that uses nitrifying bacteria entrapped in polymer pellets in an aerobic tank and denitrifying sludge in an anoxic tank removed >90% of the ammonia N. Soluble P was effectively recovered (>95%) as calcium phosphate (17% P2O5). Pathogens (i.e., salmonellae, enterococci) were reduced at least 3 logs. Overall, our results indicate that systems without lagoons are feasible.