A kinetic evaluation of anaerobic treatment of swine wastewater at two temperatures in a temperate climate zone

A static granular bed reactor (SGBR) was used to treat swine wastewater at 24 and 16 °C. At 24 °C, the organic loading rate (OLR) was 0.7–5.4 kg COD/m3 day and the average chemical oxygen demand (COD) removal efficiency was 88.5%, respectively. Meanwhile, at 16 °C, the OLR was 1.6–4.0 kg COD/m3 day and the average COD removal efficiency was 68.0%, respectively. The SGBR acted as a bioreactor as well as a biofilter. After backwashing, the recovery of COD removal was not a function of an OLR but recovery time, while that of TSS removal was not a function of either recovery time or the OLR. The maximum substrate utilization rate (kmax) ratio was 1.89 between 24 and 16 °C, and the half velocity constant (Ks) ratio was 1.22, and the maximum specific growth rate (μmax) ratio was 4.71. In addition, the temperature–activity coefficient in this study was determined to be 1.09.