This study has the goal to study the manure solid–liquid separation efficiency by screening, under different screen opening sizes and pit disposal time. In addition, the objective includes to establish and recommend an optimum period of storage, under tropical climate conditions that may maintain both manure without significant physical–chemical changes and high solid–liquid separation efficiency. It was found that to avoid the extensive degradation of swine manure and excessive solubilization of mineral and organic species under tropical climate, the solid–liquid separation process must be performed as soon as possible. Preferably, this separation should be performed in a time period shorter than eight days. As soon as this process is performed, with the efficiency of solid removal, it will decrease the ammonification and the overload of a subsequent advanced biological treatment. The storage time under the studied conditions showed an increase in the soluble COD that can cause problems in the efficiency of solid–liquid separation
and difficulties for screening.

For more information the full article can be found at http://www.sciencedirect.com/science/journal/09608524