Solar photocatalytic oxidation: a sustainable tool for reclaiming biologically treated municipal wastewater for high quality demand re-use?

摘要

Secondary effluents of different municipal wastewater treatment plants have been treated by heterogeneous photocatalytic oxidation with 1 or 10 g TiO_2/l in lab scale stirred vessel reactors using UV-A lamps. The results show that it is generally possible to use solar photocatalytic oxidation as a sustainable process for removing organics from biologically treated municipal wastewaters in order to reclaim them for high-quality re-use options. Also disinfection was achieved. However, the obtained kinetic data show that area demand for solar photocatalytic oxidation for reclamation of municipal effluents is high even with high sky and solar radiation. In order to avoid contaminants which cannot be removed by advanced oxidation processes (like heavy metals), it is recommended that solar photocatalytic oxidation is applied for reclaiming biologically treated greywater separately collected in ecological sanitation schemes (without mixing it with toilet wastewater or industrial wastewater) instead of biologically treated municipal wastewaters.