Bioremediation of urban river wastewater using Chlorella vulgaris microalgae to generate biomass with potential for biodiesel production

Abstract

<jats:p>The production of biofuels through microalgae biomass represents a new generation of raw materials from renewable sources to meet society’s clamors and growing insertion in the market of fuels from products that could grant the planet a sustainable future. The present study assesses the biomass obtained from microalgae Chlorella vulgaris when grown in urban wastewater, extracting the lipids from the biomass and performing Gas Chromatography analysis of fatty acid methyl esters (FAME) composition after submitting the lipids through the transesterification process. The microalgae cultivation was monitored through chlorophyll (a) analysis and the highest cell growth was 845.8 µg L-1 using urban wastewater as growth medium. The nutrients of interest were monitored for primary concentration of 8.06 ± 0.06 mg L-1 of ammoniacal nitrogen, 12.27 ± 0.27 mg L-1 of nitrate and 21.22 ± 0.85 mg L-1 of phosphate, reducing about 99% of ammoniacal nitrogen and nitrate, along with reducing 87% of phosphate. The lipid constitution extracted from 3.7 g of dry biomass of Chlorella vulgaris after cultivation using urban wastewater, was 7.7%. The lipids extracted from the Chlorella vulgaris biomass are suitable biodiesel production regarding the amounts of FAMEs identified, after the analysis carried out, the comparison of the results obtained with other studies and the hypotheses evaluation.</jats:p>

Tratamento de lodo de aterro: uma proposta baseada na perspectiva da bioeconomia circular

“…However, phosphorus was removed in other concentrations and up to 80.51% the crop containing the WC medium (control) which is where the optimal condition for microalgae growth is found. Other photobioreactors showed an efficiency range of 6.61% in the 50% slurry concentration and 44.32% in the concentration of domestic effluent (100%) show by Table 5, being below the result achieved in the reference (Marques, et al, 2020) urban wastewater which was up to 70% phosphorus removal for the same concentration of wastewater from urban rivers, however, the initial phosphorus concentrations in the Research, Society and Development, v. 11, n. 3, e12911326075, 2022 (CC BY 4.0) | ISSN 2525-3409 | DOI: http://dx.doi.org/10.33448/rsd-v11i3.26075 author's work are lower than the initial concentrations of the present study, being 21.22 mg.L -1 and 6.32 mg L -1 , initial and final, respectively, in this study 100.22±0,27 mg.L -1 was identified, reducing to 55.80±2,13 mg L -1 , initial and final, respectively, with an efficiency of 44.32%.…”

“…These bioproducts can even be sold helping to pay the costs in the entire treatment system. Microalgae can be used as biofuels (biomethane, biodiesel and bioethanol) (Xiao, et al, 2019;Maia, et al, 2020) and even as biopolymers for the development of bioplastics, which can move the regional socioeconomic scenario (Marques, et al, 2020;Duarte, et al, 2021).…”

Estudo da qualidade das águas superficiais na foz do rio Lucaia, Salvador (BA), Brasil

“…Brasil (Moreira, 2011;Moreira, 2014;Silva et al, 2014;Moreira et al, 2016;Cardoso et al, 2020;Marques et al, 2020).…”

“…Em um estudo feito por Marques et al (2016) também no rio Lucaia, verificando a interferência da amplitude da maré na qualidade das águas superficiais deste rio, foi apresentado maior valor para clorofila (a) na maré baixa com concentração de 650 μg/L, estando acima do que é permitido pela legislação (≤ 30 μg/L). A clorofila (a) é considerada como um indicador representativo da biomassa algal, sendo a principal variável para determinação do estado trófico de corpos d'água (CETESB, 2016), portanto os valores acima de ≤ 30 μg/L podem ser justificados pela fonte de despejo de efluentes domésticos, que influencia no aumento da oferta de nutrientes disponíveis no meio, favorecendo a proliferação de algas (Marques et al, 2020;Marques et al, 2017).…”

Mecanismos de remediação dos hidrocarbonetos policíclicos aromáticos do petróleo utilizando microalgas e cianobactérias com vistas a bioeconomia circular

“…A bioeconomia circular é uma economia onde são utilizados recursos biológicos para geração de produtos de alto valor agregado de forma sustentável, onde a recuperação de resíduos ou subprodutos de base biológica pode tanto prevenir a poluição ambiental quanto promover transformação potencial dos resíduos em produtos comercializáveis (Salvador et al, 2021). Devido a produção de biomassa de alto valor agregado, sua capacidade adaptativa a ambientes adversos e por captar o CO2 transformando-o em O2, as microalgas e cianobactérias têm se mostrado como microrganismos com processos biotecnológicos promissores para o cultivo em água residual e geração de bioprodutos provenientes da biomassa com possibilidade de aplicação industrial (Marques et al, 2020).…”