The field experiment was performed on a swine farm located in
Changle (Fuzhou), Fujian in Southeast China. The farm kept nearly
10,000 pigs with a daily discharged effluent of about 150 m3. There
were more than 1000 m2 deserted sandy lands in the backyard,
giving sufficient space for the experimentation, as well as the possible
future development of a wastewater treatment system.
Pigs involved in this study were all female. Their average live
weight was estimated to be 240 kg. Each of the pigs produced
approximately 15–20 kg of droppings and urine a day. The total
number of animals for the experiment remained 45 throughout.
They were separated in 14 pens on a same row in a pig house
(Fig. 1). The concrete floor of the pen was sloped to allow drainage
into a 37 12 cm2 outlet at the base of the wall. Pig manure accumulated
in the outlet channel outside the pens was removed by dry
muck-out before pen cleaning. The pens were cleaned every one or
two days, producing about 0.5 m3 day1 of wastewater on average