Greywater treatment by constructed wetlands in combination with TiO2-based photocatalytic oxidation for suburban and rural areas without sewer system.

In this study greywater treatment through constructed wetlands and subsequently through TiO2-based photocatalytic oxidation was investigated. Through constructed wetlands treatment the organic substances have been reduced greatly. For further removal of organic substances and pathogens, a TiO2-based photocatalytic oxidation process was used subsequently. The results showed that the treated greywater through constructed wetlands and subsequent through TiO2-based photocatalytic oxidation with short irradiation time (3 hours irradiation time) met the requirements of European bathing water quality easily. Therefore, the greywater treated with the processes combination can directly be reused for non-potable purposes. Moreover, since residual organic substances through TiO2-based photocatalytic oxidation with long irradiation time can be eliminated almost totally, it is also possible that treated greywater is used for groundwater recharge as a drinking water resource.