Biochar production from microalgae: a new sustainable approach to wastewater treatment based on a circular economy

Jorge Alberto Vieira Costa; Munise Zaparoli; Ana Paula Aguiar Cassuriaga; Bruna Barcelos Cardias; Bruna da Silva Vaz; Michele Greque de Morais; Juliana Botelho Moreira

doi:10.1016/j.enzmictec.2023.110281

Biochar production from microalgae: a new sustainable approach to wastewater treatment based on a circular economy

Enzyme Microb Technol. 2023 Sep:169:110281. doi: 10.1016/j.enzmictec.2023.110281. Epub 2023 Jun 25.

Authors

Jorge Alberto Vieira Costa¹, Munise Zaparoli², Ana Paula Aguiar Cassuriaga³, Bruna Barcelos Cardias², Bruna da Silva Vaz⁴, Michele Greque de Morais⁵, Juliana Botelho Moreira⁶

Affiliations

¹ Laboratory of Biochemical Engineering, College of Chemistry and Food Engineering, Federal University of Rio Grande, Rio Grande, RS, Brazil; Bioprocess Engineering and Biotechnology Department, Federal University of Paraná, Curitiba, PR, Brazil.
² Bioprocess Engineering and Biotechnology Department, Federal University of Paraná, Curitiba, PR, Brazil.
³ Laboratory of Biochemical Engineering, College of Chemistry and Food Engineering, Federal University of Rio Grande, Rio Grande, RS, Brazil.
⁴ Laboratory of Microbiology and Biochemistry, College of Chemistry and Food Engineering, Federal Uni-versity of Rio Grande, Rio Grande, RS, Brazil. Electronic address: bruna_vaz_bg@hotmail.com.
⁵ Laboratory of Microbiology and Biochemistry, College of Chemistry and Food Engineering, Federal Uni-versity of Rio Grande, Rio Grande, RS, Brazil. Electronic address: migreque@yahoo.com.br.
⁶ Laboratory of Microbiology and Biochemistry, College of Chemistry and Food Engineering, Federal Uni-versity of Rio Grande, Rio Grande, RS, Brazil. Electronic address: julianapvi@yahoo.com.br.

PMID: 37390584
DOI: 10.1016/j.enzmictec.2023.110281

Abstract

The generation of wastewater due to human activities are the main responsible for environmental problems. These problems are caused by the large amount of organic and inorganic pollutants related to the presence of pesticides, metals, pathogens, drugs and dyes. The photosynthetic treatment of effluents emerges as a sustainable and low-cost alternative for developing wastewater treatment systems based on a circular economy. Chemical compounds present in wastewater can be recovered and reused as a source of nutrients in microalgae cultivation to produce value-added bioproducts. The microalgal biomass produced in the cultivation with effluents has the potential to produce biochar. Biochar is carbon-rich charcoal that can be obtained by converting microalgae biomass through thermal decomposition of organic raw material under limited oxygen supply conditions. Pyrolysis, torrefaction, and hydrothermal carbonization are processes used for biochar synthesis. The application of microalgal biochar as an adsorbent material to remove several compounds present in effluents is an effective and fast treatment. This effectiveness is usually related to the unique physicochemical characteristics of the biochar, such as the presence of functional groups, ion exchange capacity, thermal stability, and high surface area, volume, and pore area. In addition, biochar can be reused in the adsorption process or applied in agriculture for soil correction. In this context, this review article describes the production, characterization, and use of microalgae biochar through a sustainable approach to wastewater treatment, emphasizing its potential in the circular economy. In addition, the article approaches the potential of microalgal biochar as an adsorbent material and its reuse after the adsorption of contaminants, as well as highlights the challenges and future perspectives on this topic.

Keywords: Circular economy; Hydrothermal carbonization; Microalgae biomass; Pyrolysis; Torrefaction.

Publication types

Review

MeSH terms

Biomass
Carbon
Charcoal* / chemistry
Humans
Microalgae*
Wastewater

Substances

biochar
Charcoal
Wastewater
Carbon