Can microalgae grown in wastewater reduce the use of inorganic fertilizers?

Alternatives to conventional inorganic fertilizers are needed to cope with the growing global population and contamination due to the production and use of those inorganic compounds. The recovery of nutrients from wastewater and organic wastes is a promising option to provide fertilization in a circ...

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Detalhes bibliográficos
Autores: Álvarez González, Ana, Uggetti, Enrica|||0000-0001-6919-485X, Serrano Porta, Lydia|||0000-0003-3776-3370, Gorchs Altarriba, Gil|||0000-0002-2073-2597, Ferrer Martí, Ivet|||0000-0002-4568-4843, Díez Montero, Rubén|||0000-0001-8435-0195
Formato: artículo
Fecha de publicación:2022
País:España
Recursos:Universitat Politècnica de Catalunya (UPC)
Repositorio:UPCommons. Portal del coneixement obert de la UPC
Idioma:inglés
OAI Identifier:oai:upcommons.upc.edu:2117/373076
Acesso em linha:https://hdl.handle.net/2117/373076
https://dx.doi.org/10.1016/j.jenvman.2022.116224
Access Level:acceso abierto
Palavra-chave:Microalgae -- Biotechnology
Water
Biofertilizer
Algal biomass
Circular bioeconomy
Agronomic tests
Resource recovery
Microalgues -- Biotecnologia
Àrees temàtiques de la UPC::Desenvolupament humà i sostenible::Enginyeria ambiental::Tractament de l'aigua
Descrição
Resumo:Alternatives to conventional inorganic fertilizers are needed to cope with the growing global population and contamination due to the production and use of those inorganic compounds. The recovery of nutrients from wastewater and organic wastes is a promising option to provide fertilization in a circular economy approach. In this context, microalgae-based systems are an alternative to conventional wastewater treatment systems, reducing the treatment costs and improving the sustainability of the process, while producing nutrient-rich microalgal biomass. The aim of the present study is to evaluate the use of microalgal biomass produced during domestic wastewater treatment in high rate algal ponds as a biofertilizer in basil crops (Ocimum basilicum L.). Wastewater was successfully treated, with removal efficiencies in the secondary treatment of 69, 91 and 81% in terms of chemical oxygen demand (COD), total inorganic nitrogen (TIN) and phosphates (PO43–P), respectively. The microalgal biomass, composed mainly by Scenedesmus, presented the following composition: 12% of dry weight and nutrients concentration of 7.6% nitrogen (N), 1.6% phosphorus (P) and 0.9% potassium (K). The study compared the performance of 3 different fertilizers: 1) microalgae fertilizer (MF), 2) inorganic fertilizer (IF) as positive control and 3) the combination of both microalgae and inorganic fertilizer (MF + IF). Comparable plant growth (i.e., number of leaves, shoot fresh and dry weight and leaf fresh weight) was observed among treatments, except for leaf dry weight, which was significantly higher in the IF + MF and MF treatments (28 and 27%, respectively) in comparison with the control. However, the microalgae treatment provided the lowest chlorophyll, N and K leaf content. In conclusion, this study suggests that combining microalgae grown in wastewater with an inorganic fertilizer is a promising nutrients source for basil crops, enhancing the circular bioeconomy.