14 July 1995

Air keeps slurry smells down – and profits up

USING air to treat slurry and dirty water can cut management costs, storage requirements, crusting and smell, according to Livestock Systems.

Pushing the merits of the Pore-tec aeration system, the Bristol-based company claimed the most effective way of treating slurry was to use very small oxygen bubbles.

"The ultra-fine bubbles are more efficient than conventional aerators," said the firms Brian Mees. "Smaller bubbles present a greater surface area for rapid oxygenation of the slurry which cuts smell and crust formation."

He claimed Pore-tec was cheap to run, as it required only a one-bar compressor, which used little electricity.

Treatment takes place in two tanks. Cleaner liquid overflows from the first tank into the second for further treatment.

"Dirty water from the second tank can be treated enough for irrigation on to saturated land, as the biological oxygen demand is reduced," said Mr Mees. "This saves on storage and the slurry is easier to spread and less pollutant, but still has nutrients."

Tanks measuring 2.56m diameter and 2m high cost £1200 each and the Pore-tec costs £2500. &#42