Microalgae for sustainable production of bioproducts and reclaimed water
Total activity: 10
Type of activity
AGENCIA ESTATAL DE INVESTIGACION
Funding entity code
Microalgae-based wastewater treatment systems have been studied with great interest due to the advantages of microalgae-bacteria consortia. These nature-based systems have demonstrated the capacity to remove organic matter and nutrients from wastewater in a lowcost way. In addition, microalgal biomass can be used to produce biogas and biofertilizers. However, the main drawback of these systems is the land requirement of high rate algal ponds, which is much higher than that of conventional wastewater treatment systems, so that their implementation is not feasible in urban agglomerations or densely populated areas. As an alternative, the AL4BIO concept proposes to use microalgae-based systems as tertiary wastewater treatment in order to obtain reclaimed water and bioproducts. In this way, the secondary effluent will be used as growth media for microalgae and cyanobacteria to eventually obtain bioproducts from the biomass, and also to obtain reclaimed water to be reused. On the one hand, the abilities of microalgae-based treatment systems for the removal of nutrients, micropollutants and heavy metals, and consequently the production of high quality reclaimed water, will be analysed. On the other hand, the production of high-value bioproducts from the microalgae and cyanobacteria biomass, such as polyhydroxyalkanoates (PHA), biological pigments, biostimulants and biopesticides, will be studied. PHA can be used for the production of bioplastics; chlorophylla, carotenoids and phycobiliproteins are pigments which can be found in microalgae and cyanobacteria; and microalgae also contain growth regulators phytohormones such as auxins, cytoquinines and salicylic acid, and biopesticides such as antibiotics, antifungal, insect repellents and plant immune system stimulators, which are of high interest in agriculture. Finally, the residual biomass, after bioproducts extraction, will be used to produce biogas, according to the circular economy principles. As a tertiary treatment, this concept could be implemented in any wastewater treatment plant, following any biological secondary treatment, in order to treat all or only part of the flowrate, depending on the land availability and the reclaimed water needs. In this context, the overall objective of the AL4BIO proposal is to study and optimize two alternative photobioreactors for tertiary wastewater treatment, microalgae and cyanobacteria biomass production, and bioproducts recovery. The cultivation systems are: open thin-layer photobioreactors and closed tubular photobioreactors. Their performance and biomass production will be analysed and optimised under different environmental and operational conditions. The obtained bioproducts will be characterised, while the biogas production from residual biomass after bioproducts extraction will also be evaluated and optimised. Mathematical modelling will be used to optimise the performance of the photobioreactors and simulate different potential scenarios. The methodology will be completed with a technical, economic and social analysis, by means of the environmental life cycle assessment (E-LCA), life cycle costing (LCC) and social life cycle assessment (S-LCA) methodologies. On the whole, AL4BIO will provide useful scientific and technical knowledge and advances on the topic of microalgae-based systems towards the production of clean water and bioproducts for agricultural and industrial applications, within the framework of the circular economy.
Garcia, M.; Matamoros Mercadal, Víctor; Uggetti, E.; Diez Montero, Ruben; Garcia, J. Environmental Research Vol. 194, p. 110278:1-110278:11 DOI: 10.1016/j.envres.2020.110278 Date of publication: 2021-03 Journal article
Rueda, E.; Garcia, M.; Diez Montero, Ruben; Vila, J.; Grifoll, M.; Garcia, J. Bioresource technology Vol. 295, p. 122233:1-122233:10 DOI: 10.1016/j.biortech.2019.122233 Date of publication: 2020-01 Journal article