An innovative approach to the application of ultrasounds to remove polyethylene microspheres from activated sludge
[EN] During the secondary treatment of Wastewater Treatment Plants (WWTP) previous studies have reported that microplastics (MPs), which correspond to plastic fragments smaller than 5 mm, are mostly retained in the activated sludge. Since the sludge can be applied as a fertilizer in agricultural lan...
| Autores: | , , |
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| Tipo de recurso: | artículo |
| Fecha de publicación: | 2021 |
| 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:10251/182179 |
| Acceso en línea: | https://riunet.upv.es/handle/10251/182179 |
| Access Level: | acceso abierto |
| Palabra clave: | Microplastic Polyethylene Activated sludge Ultrasound INGENIERIA QUIMICA 14.- Conservar y utilizar de forma sostenible los océanos, mares y recursos marinos para lograr el desarrollo sostenible |
| Sumario: | [EN] During the secondary treatment of Wastewater Treatment Plants (WWTP) previous studies have reported that microplastics (MPs), which correspond to plastic fragments smaller than 5 mm, are mostly retained in the activated sludge. Since the sludge can be applied as a fertilizer in agricultural land, the presence of MPs in this matrix can lead to soil contamination. In this study, the application of ultrasounds at a frequency of 80 kHz was tested to remove polyethylene (PE) microspheres from activated sludge samples in order to reduce their concentration in this organic matrix. The application of ultrasounds at a power of 50 W and 8 min 45 sec promoted the removal of 48 ± 4% of MPs from the mixed liquor (2820 ± 51 mg/L of TSS). However, under the same operating conditions, 12 ± 4% of MPs were recovery from the concentrated mixed liquor (9395 ± 164 mg/L of TSS). For the concentrated sludge, a higher power and a longer sonication time (80 kHz; 90 W; 30 min) was necessary to improve the MP recovery. Under these conditions 38 ± 4% of MPs were removed from the sludge. This is the first study applying ultrasounds to remove MPs from activated sludge and the results indicate that ultrasonication can be a suitable instrument in minimizing the concentration of PE microspheres in activated sludge, and thereby minimizing soil contamination when biosolids are applied to agriculture. |
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