Scope of the project

The novelty of our proposed research project relies on developing a scheme based on which the liquid fraction (i.e.condensate) of the municipal fermentable household waste will be co-managed with the municipal wastewater. The condensate may contain substantial organic load (as we have seen from assessing its characteristics). It is then proposed to mix the condensate with the municipal wastewater and handle this as a new wastewater type in an optimal manner. Given the fact that the resulting stream, depending on the drying conditions, can have a substantially high organic load, it may be first led to anaerobic digestion for the production of biogas.

A high-rate digester, such as a Periodic Anaerobic Baffled Reactor (PABR) is most suitable for this type of treatment. The digester effluent may then be treated in a conventional activated-sludge process, which of course will have different operational characteristics than the standard activated sludge process for municipal wastewater treatment. It should be noted that nutrient removal should be achieved in this process, so that effluent requirements are met.

In addition, the possibility of using Microbial Fuel Cell technology for wastewater treatment with direct production of electricity for the digester effluent is worth being explored as a viable alternative. Finally, the excess sludge generated by the activated sludge process may be recycled to the digester. Currently, the excess sludge generated through the management of sewerage in an Activated Sludge Process is being used as a feedstock for the production of methane in Anaerobic Digestion. Another option that we are suggesting is to research the effect of adding condensate directly to the anaerobic digester. This option is less radical than the one described before. However, it is worth researching it could be implemented without any new infrastructure.

Hence, this is the scope of the proposed research in this project, i.e. to devise an overall energy-effective treatment scheme for the co-management of the wastewater and solid waste condensate streams.