Biological pilot treatment reduces physicochemical and microbiological parameters of dairy cattle wastewater.

The objectives of the present study were to characterize and evaluate a pilot treatment unit (PTU) for dairy cattle wastewater (DCW) in relation to its efficiency in reducing the physicochemical and microbiological parameters and possible application of this fertilizer in organic production. A PTU was set up, composed of the following elements: a dung pit of 7.8 m, already in place; a septic tank; a set of anaerobic biological filters comprising an upflow filter and a downward-flow filter filled with fragments PVC corrugated conduit; and two constructed wetland systems (CWSs) of horizontal subsurface flow in two parallel routes (Routes 1 and 2), controlled by means of a flow rate divider box.