| Abstrakt: |
The goal of this study was to determine the effects of suspended solids (SS) adsorption properties, as well as the concentration of SS, on the mechanisms governing ammonia volatilization from liquid dairy manure. Pertinent properties that influence total ammoniacal nitrogen (TAN = NH4+ + NH3) adsorption on SS, including particle size distribution (PSD) and volatile solids (VS), of manures from three dairy operations with different feed rations were evaluated. The main parameters governing ammonia volatilization from liquid manure, i.e., the dissociation constant (Kd), the fraction of un-ionized ammonia (β), and the overall mass transfer coefficient (KO) of ammonia, for the three manures were determined in a laboratory convective emission chamber. The adsorption characteristics of the SS of the manures from the three dairies were significantly different. In particular, the PSD and VS for the SS of the manures from all dairies were significantly different. Even though the adsorption properties were significantly different among the SS from all three manures, their net effects on ammonia volatilization, at the same concentration, were not significantly different. Briefly, SS adsorption properties did not significantly affect either Kd, β, or KO, but SS concentrations significantly affected them all. Removal of SS via solids-liquid separation would therefore exacerbate ammonia loss from liquid dairy manure. Overall, these findings reveal that increasing SS concentration hinders ammonia volatilization from liquid dairy manure, whereas differences in the SS characteristics do not affect the volatilization process in a significant manner. [ABSTRACT FROM AUTHOR] |
