The aim of the project is the development of a prototype of a water treatment system based on the sequential combination of three technologies: electrocoagulation, electro oxidation and a technology for the recovery of generated hydrogen for energy saving and the reutilisation of the resulting regenerated water for different applications more efficient in terms of wastewater treatment and self-sustaining in terms of energy needs.
The idea is to develop a wastewater treatment system aiming at closing the water cycle, by integrating energy and water management, where the electricity generated through the hydrogen conversion is used to keep the system working and the extracted residues from the waste water treatment are reused inside the food and dairy production process to cover different needs. Therefore, the project would develop a system with technologies that have still not been jointly developed together with hydrogen recovery. The hydrogen generation from EC or EO systems for electricity production to be completely used to feed the wastewater system has not yet been developed. Still lot of research is needed for the generation of hydrogen from these two water treatment technologies It can be stated as strength that such kind of electrochemical and hydrogen valorisation technologies have not still been jointly considered. As far as we are concerned there is no previous work focused on the recovery of generated hydrogen from EC or EO systems for electricity production, neither in bench-scale nor in real-life. Indeed, the scientific literature does not show any study considering the conversion of this electrochemically generated hydrogen into energy.
Proposed proof-of-concept process diagram (click to enlarge)
The project aims to treat dairy effluents composed by wastewater and whey by means of electrochemical processes in order to:
- achieve the desired water quality to its reuse
- recover the hydrogen generated during treatment as a by-product in a secondary power generator feeding the main wastewater treatment technologies
- reduce and valorise the electro generated sludge.
The first necessary step is based on the elimination of fats and oils in order not to interfere in further processes. Afterwards, electrocoagulation (EC) and electro oxidation (EO) as Electrochemical Advanced Oxidation Processes (EAOP) will be coupled and upgraded in order to remove/reduce suspended solids, colour and turbidity. Post-treatment based on Capacitive Deionisation Technology (CDI) will be developed to obtain appropriate conductivity level for water reutilization.