July 3, 2007

US research shows pig waste system can reduce greenhouse gases

A research conducted by the Agricultural Research Service (ARS) show that pig-waste management system dramatically reduces greenhouse gases emanating from swine farming operations.

Started in 2004, the study, based on the technology combination by the ARS and companies from the US, Spain and Japan, utilizes a series of tanks and staging areas spread out over 200 feet. In three stages, it separates the solids from the liquids in the wastewater, recovers the soluble phosphorus and processes the solids into fertilizer for plants.

Earlier tests show the system removed more than 97 percent of total suspended solids from the wastewater. It also stripped the water of 95 percent of its total phosphorus, 99 percent of its ammonia and more than 97 percent of its odour-causing components.

This patented system is called the "Super Soil System," named for Super Soil Systems USA, Inc., a North Carolina firm that implemented and is marketing the system.

In the latest trial conducted on a 4,360-head pig finishing operation in North Carolina, the ARS scientists discovered that replacing conventional anaerobic pig-waste lagoon practices with the new system reduced greenhouse-gas emissions from the operation by 99 percent. 

The system is fully automated, using integrated sensors with a programmable logic controller for round-the-clock operation and works all-year round. In earlier tests, the system also proved that it consistently removed more than 95 percent of the ammonia and total organic nitrogen present in the manure after the separation of the liquids, even when temperatures are below freezing.