Influence of pH and Temperature on Struvite Purity and Recovery from Anaerobic Digestate
| Autor: | Francisco J. Molina, Darío Naranjo-Fernández, Miller Alonso Camargo-Valero, Adriana Matamoros-Veloza, B. Fernández, Carolina González-Morales |
|---|---|
| Přispěvatelé: | Producció Animal, Sostenibilitat en Biosistemes |
| Rok vydání: | 2021 |
| Předmět: |
Geography
Planning and Development chemistry.chemical_element TJ807-830 Management Monitoring Policy and Law TD194-195 Renewable energy sources Ammonia chemistry.chemical_compound nutrient recovery GE1-350 Volatilisation Environmental effects of industries and plants Renewable Energy Sustainability and the Environment Precipitation (chemistry) Phosphorus struvite crystallisation sustainable sanitation Phosphate Nitrogen saturation index Environmental sciences chemistry Wastewater Struvite centrate Nuclear chemistry |
| Zdroj: | IRTA Pubpro. Open Digital Archive Institut de Recerca i Tecnologia Agroalimentàries (IRTA) Sustainability, Vol 13, Iss 10730, p 10730 (2021) Sustainability Volume 13 Issue 19 |
| ISSN: | 2071-1050 |
| Popis: | The precipitation of struvite (MgNH4PO4.6H2O) from wastewater streams simultaneosuly recovers nitrogen (N) and phosphorus (P) for reuse as fertilisers. Struvite crystallisation is controlled by pH, saturation index, temperature and other ions in the solution (e.g., Ca2+, Mg2+ and CO32−). This work studies the effect of pH and temperature on phosphorus and nitrogen removal via struvite precipitation and the quality of the resulting precipitate product (i.e., crystal size, morphology and purity). Struvite was precipitated in batch reactors from the supernatant produced during anaerobic sludge dewatering at a wastewater treatment works, under controlled pH (8, 9 and 10) and temperature (25, 33 and 40 °C) conditions. The optimal P removal as struvite, reduction of the co-precipitation with Ca and the increase in particle size of the struvite precipitates were determined. The results showed that temperatures of 33 °C and 40 °C are not recommended for struvite precipitation—i.e., at 33 °C the purity is lower, and at 40 °C the ammonia losses are induced by volatilisation. At all pH-tests, the P removal efficiency was > 93%, but the highest phosphate content and purity as struvite were obtained at a pH of 9.0. The optimum pH and temperature for the formation of large crystals (84 µm) and a high purity (> 70%) of the struvite precipitates were 9 and 25 °C, respectively. |
| Databáze: | OpenAIRE |
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