Abstract
The performance of the ANAMET anaerobic-aerobic system for treating the alcohol stillage wastewater was investigated by conducting pilot plantscale experiments. The ANAMET system is combined with a thermophilic anaerobic contact process and a conventional activated sludge process.
In the anaerobic contact process unit, BOD removal efficiency of 87% and COD removal efficiencies ranging from 82 to 83% were obtained under the following operational conditions : the temperature ranged from 53 to 55°C, the HRT ranged from 4 to 5 days and the COD loading rate ranged from 9.11 to 11.7 kg-COD·m-3·d-1. The optimum ranges of influent COD concentration, COD loading rate and sludge age in the aerobic activated sludge process unit were 2,000-3,000mg·l-1, 0.55-1.10kg-COD·m-3·d-1 and 8-15days, respectively. Through this investigation, it was found that the ANAMET anaerobic-aerobic system provided efficient performance in the methane production, the improvement of effluent water qaulity and the decrease of sludge production. This anaerobic-aerobic combination system is considered to be suitable for the treatment of wastewater with high concentration of solids.
