Development and evaluation of an alternative method for municipal wastewater treatment using homogeneous photocatalysis and constructed wetlands

Wastewater collection and treatment is an important parameter of sustainable development. In Mediterranean region especially, the design and operation of competitive wastewater treatment systems for small communities and touristic facilities is a challenge to wastewater engineers. Within this context an alternative method of wastewater treatment has been developed that is based on solar photocatalytic oxidation and natural processes. The system combines the synergetic action of the homogeneous photocatalytic oxidation with the surface flow constructed wetlands in order to utilize the high solar irradiation and the ability of the constructed wetlands to improve water quality through natural processes. Aim of this work is to present the design, development, and experimental evaluation of the combined system. Experiments were conducted at laboratory scale using artificial as well as solar irradiation, for the treatment of both synthetic and cesspool wastewater. The data evaluation revealed that the combined system may effectively reduce the organic load and nutrients of wastewater, even in cases of great inflow variability, in terms of hydraulic and organic load, and thus may be proven a promising, competitive and environmental friendly solution for wastewater treatment in the near future.