Both coagulation-Z08 and yeast-Z08 methods effectively reduced COD (Fig. 1). After coagulation, COD dropped from 13,516 to 2806 mg/L. After Z08 was added, COD dropped rapidly for 48 h and stabilized around 300 mg/L. The yeast-Z08 operation reduced the COD by 96.5% after 168 h. Comparing to direct Z08 treatment, neither operation showed advantage in effluent quality or COD removal efficiency and thus was unnecessary. So direct Z08 degradation of soybean wastewater was much preferred.