Studies on Moisture Evaporation and Economical Analysis for Composting of Piggery Slurry

To evaluate composting process of piggery slurry, we made bench scale composting reactor, and investigated the input and output of mass, moisture evaporation, volatile solid degradation, and running cost. For 15 days experimentation the results was as followed, The quantity of sawdust used was 0.47ton(18,000won) per 1ton slurry. The amount of moisture evaporated was 16.8kg/kg VS degradated. Total evaporation and VS degradation were 24.8%, 5.7% respectably. To analysis the running cost of that, we included only two factors, sawdust cost and compost income. The compost price to sell was 63won/kg(50% of market price) it made 8,694won income to 756 won loss, but 25won/kg, it was loss per 1 ton slurry in the current pig farmer's condition. This cost was of pig production cost and damage strongly to pig farmers to treat it.