In this lab-scale study, domestic wastewater is subjected to a chemical biological adsorption (A-stage), followed by treatment in an innovative roof installed parallel plate microalgae biofilm reactor for nutrient immobilization (I-stage). The A-stage process was operated at a hydraulic retention time (HRT) of 1h and a solid retention time of 1day (FeSO4 as flocculant). The I-stage, which consequently received the effluent of the A-stage process, was operated at an HRT of 1day and exposed to natural light. The overall system removed on average 74% of the total chemical oxygen demand, 82% of the total suspended solids, 67% of the total nitrogen and 96% of the total phosphorous in the wastewater. The design involves a relatively low capital and operating cost which is in the order of 0.5€/m3 wastewater treated. These aspects suggest that the A/I process can be used as a decentralized domestic wastewater treatment system.
Bibliographical noteFunding Information:
This work was supported by the Institute for the Promotion of Innovation by Science and Technology-Strategic Basic Research (IWT-SBO) Sunlight Project – Lipid-based, high value products and renewable energy from microalgae grant 80031 and Ghent University grant 179I16D9W . This work is part of the Ghent University Multidisciplinary Research Partnership (MRP) – Biotechnology for a sustainable economy (01 MRA 510W). The authors would like to thank Tom Hennebel, Haydee De Clippeleir, Sofie Van Den Hende, and Joachim Desloover for critically reading the manuscript and Renaat Dasseville for the assistance for the SEM analysis. A special thanks to Robin Declerck and Mike Taghon for providing logistic assistance. A special thanks to Tim Lacoere for the drawing of the graphical abstract.
- Green roofs
- Municipal wastewater
- Nutrient recovery