Assessment of Animal Waste Treatment by Means of Biodigesters on Pig Farms in the Red River

Abstract

The present study was carried out at 12 pig farms in three provinces of Hai Duong, Hung Yen and
Bac Ninh. Results showed that the daily amounts  of solid and liquid wastes were rather  large (50 -  260 kg
of solid wastes and 3 - 20 m3
 of liquid wastes). The liquid waste treatment with biodigesters decreased
the BOD5 and COD concentrations (BOD5 decreased by 75.0 - 80.8% at the sow houses and 75.89 -
80.36% at the growing-finishing pig houses; COD decreased by 66.85% and 64.94 - 69.73% at the sow
houses and growing- finishing houses, respectively). However, the COD concentration after treatment
was still higher than the hygiene standard. The soluble sulfur concentration was decreased
considerably after treatment but was still 3.63 to 7.25 times higher than the hygiene standard. The Cl
-
 
concentration was decreased little after biodigester treatment. The  Cu2+
 and  Zn2+
 concentrations in the
effluent were  within the range of hygiene standards.