Abstract
Electrodialytic technologies are defined as treatment processes that promote the removal/recovery of substances in a matrix, based on the application of low-level current intensities. Additionally, along these processes hydrogen is self-generated, allowing them to operationally produce clean energy. This energy carrier is produced due to electrolysis reactions occurring at the cathode end of the electrodialytic reactor, when using inert electrodes. Herein, hydrogen production during the electrodialytic treatment of sewage sludge and mining residues suspensions (coupled with effluent or sewage sludge), at 50 and 100 mA, was assessed. During the electrodialytic treatment of sewage sludge, hydrogen purity production achieved 33%. When effluent or sewage sludge were used as enhancements in mining residues suspensions, hydrogen purity reached 71% and 34%, respectively. Furthermore, a proton-exchange membrane fuel cell was connected to the cathode compartment of the electrodialytic reactor. The electrical energy generated from self-hydrogen produced at 100 mA achieved ≈1 V in all performed experiments. Simultaneously, critical raw materials extraction, namely phosphorus and tungsten, was evaluated. When the process was applied to mining residue suspensions combined with sewage sludge, the highest extraction ratio of phosphorus (71%) and tungsten (62%) was observed.
Highlights
Raw materials are crucial to the European Union’s economy and, as the population grows [1], more resources are needed to meet the demand
Coupling the recovery of critical raw materials from secondary resources with the empowerment of clean energy production will move towards circular economy principles [5]
Electrodialytic technologies are being shaped for critical raw materials upturn, namely phosphorus (P) from sewage sludge [8] and tungsten (W) from secondary mining resources [10]
Summary
Raw materials are crucial to the European Union’s economy and, as the population grows [1], more resources are needed to meet the demand. Coupling the recovery of critical raw materials from secondary resources with the empowerment of clean energy production will move towards circular economy principles [5]. Ion-exchange membranes allow a selective separation of cations and anions in concentrated electrolytes’ solutions [9] In this sense, electrodialytic technologies are being shaped for critical raw materials upturn, namely phosphorus (P) from sewage sludge [8] and tungsten (W) from secondary mining resources [10]. Sewage sludge can be regarded as a secondary resource of critical raw materials, e.g., due to its high P content, when compared with effluent. Sewage sludge and mining residues suspensions have in common high disposal rates and critical raw materials contents, making them attractive for electrodialytic technologies. The recovery of P and W from all matrices under treatment was assessed
Sign-in/Register to view highlights & summary Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
