2003 journal article

Comparing ammonium ion dissociation constant in swine anaerobic lagoon liquid and deionized water

Transactions of the ASAE, 46(5), 1415–1419.

Source: NC State University Libraries
Added: August 6, 2018

The dissociation constant of ammonium ion both in deionized water and swine anaerobic lagoon liquid wasdetermined experimentally in a convective emission chamber at three temperatures (15.C, 25.C, and 35.C) commonlyexperienced in lagoons in the south and southeastern regions of the U.S. Ammonium chloride (NH4Cl) salt was used to makethe solution for the deionized water tests. The dissociation constant (Kd) values obtained for NH4Cl in deionized waterapproximately doubled with every 10.C increase in liquid temperature from 15.C to 35.C. A similar trend was obtained forlagoon liquid in the 25.C to 35.C liquid temperature range, but the Kd values for the lagoon liquid were ~50% of those forNH4Cl in deionized water. However, at 15.C, the Kd value for the lagoon liquid was almost the same as for deionized water,and was 0.75 the lagoon liquid value at 25.C. Based on these results, it can be concluded that the Kd values of ammoniumion in anaerobic lagoon liquid was 50% of the value in deionized water at 25.C and 35.C, and 94% of the value at 15.C.This implies that for lagoons with characteristics similar to those of the anaerobic lagoon liquid reported in this study, theKd values (normally derived from NH4+ dissociation in deionized water) used in ammonia volatilization calculations shouldbe adjusted to a fraction of that in deionized water. More studies to determine the Kd values for lagoon liquids with differenttotal ammonia nitrogen concentrations and solid contents are needed. Studies should include the effects of temperature andperhaps distinguish between the effects of dissolved and suspended solids on the dissociation constant.