Effects of anaerobic digestion centrate pre-treatment on further nutrient recovery by membrane contactors
[EN] Hollow fibre membrane contactors (HFMCs) technology emerges as a promising solution for efficient nitrogen recovery from anaerobic digestion centrates. However, full-scale implementation requires an efficient pretreatment stage. This pre-treatment includes the increase of pH over 8.5 to maximiz...
| Autores: | , , , , |
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| Tipo de recurso: | artículo |
| Fecha de publicación: | 2025 |
| País: | España |
| Institución: | Universitat Politècnica de València (UPV) |
| Repositorio: | RiuNet. Repositorio Institucional de la Universitat Politécnica de Valéncia |
| Idioma: | inglés |
| OAI Identifier: | oai:riunet.upv.es:10251/228424 |
| Acceso en línea: | https://riunet.upv.es/handle/10251/228424 |
| Access Level: | acceso abierto |
| Palabra clave: | Anaerobic digestion centrates Ceramic membrane Coagulation Hollow fibre membrane contactor Fertiliser Nitrogen recovery |
| Sumario: | [EN] Hollow fibre membrane contactors (HFMCs) technology emerges as a promising solution for efficient nitrogen recovery from anaerobic digestion centrates. However, full-scale implementation requires an efficient pretreatment stage. This pre-treatment includes the increase of pH over 8.5 to maximize ammonia recovery and suspended solids removal to prevent membrane fouling thus extending its lifespan. This study compares different pre-treatment strategies, demonstrating its critical role in HFMC performance. Two pH-raising reagents (caustic soda and lime), the addition of coagulant (FeCl3) and flocculant (polyelectrolyte), and three solids removal methods: sedimentation, centrifugation and ultrafiltration through a ceramic membrane were evaluated by means of five sets of laboratory experiments. The most effective approach involved dosing lime to achieve pH values close to 12, followed by a 30-min settling period and a filtration process through a ceramic ultrafiltration membrane, resulting in a permeate free of suspended solids. Pre-treatment improved ammonia mass transfer and enabled ammonium recovery efficiencies in the HFMC around 90 %. An economic assessment confirmed the viability of scaling-up the process. The total cost of pre-treatment and nitrogen recovery was estimated at 2.12 <euro> per m3 of centrate treated, while generating a revenue of 0.53 <euro> per m3 of centrate treated. Integrating this pretreatment process into a full-scale urban wastewater treatment plant would increase the overall cost of treating the influent flow by only 2.8 %, highlighting its viability as a cost-effective solution for nitrogen recovery. |
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