Physical methods used for grey water treatment are sand filter, ultrafiltration, micro-filtration, reverse osmosis. Small scale experimental results have shown that grey water treated with combination of SBR (Sequence Batch Reactors) and slow sand filter has achieved the quality required for groundwater recharge (Li et al., 2001). In the study of Shin et al. (1998), the grey water treated with a combination of SBR and micro-filtration was suitable for reuse. Moreover, grey water treated with the combination of Constructed wetlands and chemical process (TiO₂–based photocatalytic oxidation) has achieved the European bathing water quality (Li et al., 2002).