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Microalgal Biofilms for Wastewater Treatment

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Microalgal Biofilms for Wastewater Treatment Microalgal Biofilms for Wastewater Treatment N.C. Boelee Microalgal Biofilms for Wastewater Treatment Nadina Catharina Boelee Thesis committee Promotor Prof. Dr R.H. Wijffels Professor of Bioprocess Engineering Wageningen University Co-promotors Dr B.G. Temmink Assistant professor, Sub-department of Environmental technology Wageningen University Dr M.G.J. Janssen Assistant professor, Bioprocess Engineering Wageningen University Other members Prof. Dr L.E.M. Vet, Wageningen University Prof. Dr Dr H.C.O. Pulz, University of Applied Sciences Lausitz (HSL), Nuthetal, Germany Prof. Dr P.N.L. Lens, UNESCO-IHE, Delft Dr M.H. Zandvoort, Waternet, Almere This research was conducted under the auspices of the Graduate School VLAG (Ad- vanced studies in Food Technology, Agrobiotechnology, Nutrition and Health Sciences). Microalgal Biofilms for Wastewater Treatment Nadina Catharina Boelee Thesis at Wageningen University submitted in fulfillment of the requirements for the degree of doctor Prof. Dr M.J. Kropff, by the authority of the Rector Magnificus in the presence of the Thesis Committee appointed by the Academic Board to be defended in public on Friday 20 September 2013 at 11 a.m. in the Aula. N.C. Boelee 216 pages Microalgal Biofilms for Wastewater Treatment, PhD thesis, Wageningen University, Wageningen, NL (2013) With references, with summaries in Dutch and English ISBN 978-94-6173-666-6 Deel je eten en het zal beter smaken. Deel je blijdschap en ze zal groter worden. Deel je zorgen en ze zullen minder zwaar zijn. Deel je enthousiasme en je zult elkaar aansteken. Deel je kennis en ze zal aangevuld worden. Deel je liefde en je zult liefde krijgen. Deel je leven en je zult mens worden. — Greet Brokerhof-Van der Waa Table of Contents 1. Microalgal Biofilms for Wastewater Treatment: Introduction . 13 Microalgae . .15 . 16 Microalgae in Wastewater Treatment . 19 Microalgal Biofilms . 19 Thesis Outline . 21 Microalgal Biofilms for the Treatment of Municipal Wastewater 2. Scenario Analysis of Nutrient Removal from Municipal Wastewater by Microalgal Biofilms . 25 Abstract . 26 Introduction . 27 Material and Methods . 28 Scenarios . .28 Calculations and Parameters . 30 Results . 32 Discussion . .34 Effluent Concentrations . 34 Area Requirement . 35 Seasonal Variation in Temperature and Light Intensity . .36 Daily Variation in Light Intensity . .37 Application of Microalgal Biomass . .37 Conclusions . .38 Acknowledgements . .39 3. Nitrogen and Phosphorus Removal from Municipal Wastewater Effluent Using Microalgal Biofilms . .41 Abstract . 42 Introduction . 43 Material and Methods . 44 Experimental Setup . 44 Microalgal Biofilm Cultivation . 46 Analytical Procedures . .47 Scanning Electron Microscopy . 48 Calculations . .48 Results . 49 Biofilm Growth . 49 Removal of Nitrate and Phosphate from Synthetic and Real Wastewater Effluent . .50 Uptake Capacity and Microalgae Washout . .52 Microalgal Biomass . 55 Photosynthetic Efficiency . .57 Discussion . .58 Conclusions . .61 Acknowledgements . .61 4. The Effect of Harvesting on Biomass Production and Nutrient Removal in Phototrophic Biofilm Reactors for Effluent Polishing . 65 Abstract . 66 Introduction . 67 Material and Methods . 68 Vertical Phototrophic Biofilm Reactor . .68 Horizontal Flow Lanes . 69 Microalgal Biofilm Cultivation . 70 Harvesting Experiments . 72 Analytical Procedures . .73 Microscopy . 74 Calculation of the Elemental Composition . 74 Results . 74 Biofilm Growth in the Vertical Biofilm Reactor . 74 - 3- Removal of NO3 -N and PO4 -P in the Vertical Biofilm Reactor . .75 Biomass Production in the Vertical Biofilm Reactor . 78 Mass Balances N and P of the Vertical Biofilm Reactor . 79 Biofilm Growth in the Flow Lanes . 81 Biomass Production Rates in the Flow Lanes . 81 Elemental Composition Biomass . 83 Discussion . .85 Conclusions . .88 Acknowledgements . .88 5. Nutrient Removal and Biomass Production in an Outdoor Pilot-Scale Phototrophic Biofilm Reactor for Effluent Polishing . .91 Abstract . 92 Introduction . 93 Material and Methods . 95 Experimental Setup . 95 Influent Characteristics . .96 Harvesting . .97 Analytical Procedures . .98 Calculation of the Elemental Composition . 99 Results . 99 Biofilm Growth . 99 Influent and Effluent Characteristics and Light Intensity . .99 Nutrient Removal . 103 Biomass Production . 106 Relationship Between Biomass Production, Nutrient Removal, Temperature and Light . .109 Discussion . .109 Conclusions . .115 Acknowledgements . .115 6. Symbiotic Microalgal-Bacterial Biofilms Remove Nitrogen, Phosphorus and Organic Pollutants from Municipal Wastewater . .117 Abstract . 118 Introduction . 119 Material and Methods . 121 Experimental Setup . 121 Microalgal Biofilm Cultivation . 123 Analytical Procedures . .124 Photosynthesis Inhibition Test . 124 Biomass Separation . 125 Results . 125 Biofilm Growth . 125 + 3- Removal of Acetate, NH4 and PO4 . .126 Symbiosis . 129 Discussion . .135 Conclusions . .137 Acknowledgements . .137 7. Microalgal Biofilms for Wastewater Treatment: General Discussion . .139 Wastewater Treatment . .141 Post-Treatment of Municipal Wastewater Effluent . 141 Treatment of Municipal Wastewater Using a Symbiotic Biofilm . .148 Biomass Production . .149 Biomass Characteristics . 149 Recovery of Nutrients . 151 Recovery of Energy . 152 Summary . 155 Appendix A: Additional Scenario Analysis Calculations and Parameters . 157 Appendix B: Anaerobic Digestion of Heterotrophic and Microalgal Biomass . 163 Appendix C: Lipid Production from Microalgae . 167 Appendix D: Penetration of Nutrients and Light . .171 References . ..
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