2010 Volume 46 Issue 2 Pages 99-107
Effect of anaerobic-aerobic circulation ratio and HRT on BOD and nitrogen removal efficiencies in simultaneous treatment of domestic wastewater and kitchen garbage disposer wastewater was investigated by using small scale Johkasou model reactors. The optimum circulation ratio and HRT were determined as 6 and 59.7 hrs to achieve target effluent water quality, BOD 10 mg l－1 and T－N 10 mg l－1. According to the results of this experiment, reactor volume of simultaneous treatment of domestic wastewater and disposer wastewater should be 1.21 times bigger than advanced domestic wastewater treatment Johkasou to attain the same performance. life cycle CO2 evaluation was conducted to compare the impacts of the following two scenarios. The first one is a present case in which kitchen garbage is incinerated with other domestic waste and domestic wastewater is treated in advanced Johkasou, and the second case is a simultaneous treatment of domestic wastewater and kitchen garbage in advanced Johkasou. In the second case, volume of the Johkasou was determined according to the results of above experiment. Potential contributions to CO2 emission in the processes of domestic waste treatment and domestic wastewater treatment were assessed by LCCO2 in these two cases, individually. Although CO2 emission in wastewater treatment process increased in a case of a simultaneous treatment of kitchen garbage and domestic wastewater, transportation amount of domestic waste was decreased and net CO2 emission was reduced by 4.2％ (－25.6 kg－CO2 house－1 year－1).
