CHANGING THE ENVIRONMENT IN SWINE BUILDINGS USING SULFURIC ACID

Abstract

Ammonia and dust concentrations in swine confinement buildings were reduced by spraying a mixture of water and sulfuric acid, by adding sulfuric acid to the swine manure, and by oxidizing the manure. The system was composed of a sprinkling system, spraying fluid at pH 5.5, and a sulfuric acid pump in the swine manure collection channel, ensuring that the pH in the swine manure never exceeded 5.5. In that way, the nitrogen, which usually escapes as ammonia gas, was kept as ammonium fluid. Above the manure collection channel was a gas monitor ensuring that the level of hydrogen sulfide did not rise to levels associated with danger to pigs or humans. Short–term observations in the swine confinement building showed a reduction of ammonia concentrations from 8 to 10 ppm down to 1 to 2 ppm and a reduction of respirable and total dust concentrations from 1.00 mg/m 3 down to 0.28 mg/m 3 and from 2.70 mg/m 3 down to 1.20 mg/m 3 . Pig performance was improved, verified by an increase in weight gain of 1074 g/day (SD = 774 g/day). There was a subjective improvement in the working environment reported by two swine confinement workers and a better utilization of swine manure as fertilizer. This suggests that a substantial improvement in the environment of swine buildings can be achieved by installing this system in swine confinement buildings.