SE—Structure and Environment: Practicalities, Costs and Effectiveness of a Floating Plastic Cover to reduce Ammonia Emissions from a Pig Slurry Lagoon

✍ Scribed by I.M. Scotford; A.G. Williams

• Publisher: Elsevier Science
• Year: 2001
• Tongue: English
• Weight: 430 KB
• Volume: 80
• Category: Article
• ISSN: 0021-8634
• DOI: 10.1006/jaer.2001.0744

✦ Synopsis

The objectives of this research were to assess the practicalities and costs of covering a lagoon of pig slurry, with a maximum slurry surface area of 525 m 2 . The lagoon was covered with 0)5 mm thick reinforced ultraviolet (UV) stabilized black, opaque polyethylene. During the covering operation, several practical di$culties were identi"ed. Since the lagoon was full, it was di$cult to estimate the size of the material required to cover the lagoon whilst ensuring su$cient space to allow the lagoon to "ll and empty. The covering operation itself required a calm day and was very labour intensive. Covering lagoons larger than the one covered in this study may necessitate them to be empty, which is often not practical in commercial pig units. The total cost of covering the lagoon was C8400 which equated to C16 m\ of slurry surface covered. If larger lagoons are covered, economies of scale come into e!ect and the material costs per unit area of slurry surface are likely to reduce, although the labour cost may increase.

Ammonia emissions were measured from both an uncovered lagoon and covered lagoon. The ammonia emissions were measured using hoods, each covering a surface area of 0)5 m. Each hood was "tted with an inlet pipe and outlet pipe. Air was forced into the hood using a 12 V fan which gave a super"cial air velocity of 0)4 m s\ across the measured surface. The ammonia #ux was measured into and out of the hoods by Ferm tubes situated in the inlet and outlet pipes. The ammonia emission rates (corrected for wind speed) from the uncovered lagoon ranged from 0)63 to 3)66 g m\ d. The #oating plastic cover prevented nearly 100% of these emissions.