AL4BIO

Description

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.

Objectives

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.

More specifically the objectives

• Use microalgae-based systems as tertiary wastewater treatment to obtain recovered water and bioproducts.
• Produce high quality recovered water thanks to the capabilities of microalgae-based treatment systems to remove nutrients, micropolishing and heavy metals.
• Produce high value bioproducts from microalgae and cyanobacteria biomass such as polyhydroxyalkanoates (PHA), biological pigments, biostimulants and biopesticides. PHA can be used for the production of bioplastics; chlorophylla, carotenoids, and phycobiliproteins are pigments that can be found in microalgae and cyanobacteria; and microalgae also contain growth regulators phytohormones such as auxins, cytokinins and salicylic acid, and biopesticides such as antibiotics, antifungals, insect repellents and plant immune system stimulants, which are of high interest in agriculture. Finally, the residual biomass will be used to produce biogas, in accordance with the principles of the circular economy.

Impact

AL4BIO project 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.

Funded by: Programa Estatal de I+D+i. Ministerio de Ciencia, Innovación y Universidades.

Duration: January 2019 – December 2021