Performance of a mechanical-chemical separator for animal liquid manures-first results

A mechanical-chemical device for solid liquid separation of pig slurry was tested for its separation efficiency in terms of nitrogen, Total Solids, phosphorous, potassium and micro elements (Cu and Zn). The device was tested with pig slurries characterised by two (3.6 and 5.6%) TS contents and with two input flow rates. Manpower, electrical requirements and economic sustainability of the equipment were also assessed. Trial results showed a good performance of the equipment in terms of separation efficiency with values up to 91.9% and 47% for TS and TKN respectively. Very good performances were observed for phosphorous and microelements separation as well with values up to 91% for P2O5 and 95% for Cu and Zn. Despite the good performances of the equipment, trained personnel is required to run the separator and high operative costs (up to 9€ per cubic meter of processed slurry) and energy costs (up to 1,4 kWh per kg of separated total nitrogen) have been estimated.