Abstract
Fishmeal factory wastewater (FFW) was anaerobically fermented. Volatile solid (VS) and BOD of FFW were 78, 200mg/l and 60, 100mg/l, respectively. BOD/VS ratio was 0.77. It was thought that FFW is subjected to biochemical degradation. But, constant methane production was low because of containing colloidal protein in the proportion of 80% to VS. The authors made it possible by development of the following processes.
1) The colloidal protein from FFW was aggregated to remove by addition of acetic acid in the proportion of 1%.
2) Methane gas was constantly generated by removing NH3 and H2S from digested water by stripping using H2SO4 and Fe2O3 as adsorbents. Gas production ratio was 0.62l/g-VS. On the methane gas production of FFW, the removal ratio of BOD and COD were 91.4%, 40.4% respectively.
