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

Adna Caroline Vale Oliveira,Natália Ribeiro Melo,Ícaro Thiago Andrade Moreira,Isadora Machado Marques

doi:10.33448/rsd-v9i7.4882

Adna Caroline Vale Oliveira, Natália Ribeiro Melo

Open Access

https://doi.org/10.33448/rsd-v9i7.4882

Copy DOI

Abstract

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.

Highlights

The innovation of technologies for the development of new sources of renewable energy is of great relevance to meet the high demands of the whole society (Cardoso et al, 2020; Ramluckan et al, 2014; Moreira et al, 2013)
As the energy production through microalgae biomass have zero-emission of Carbon Dioxide and, regarding Chlorella vulgaris, has a rate of fixation of CO2 of 251 mg L-1 to 865 mg L-1, conditional to the type of cultivation (Pragya et al, 2013), the emission limit imposed by the Paris Agreement, which provides a means of limiting the increase in temperature on Earth under 2°C defined at COP 21, would not be reached and would generate carbon credits to be sold to developed countries
In response to the world’s demands and the increase of researches in renewable energies that can meet the requests of the global market and to sustainable development, this present study aims to evaluate oil potential from dry biomass of Chlorella vulgaris grown in urban river wastewater attending to its feasibility for generating biodiesel

Summary

Introduction

The innovation of technologies for the development of new sources of renewable energy is of great relevance to meet the high demands of the whole society (Cardoso et al, 2020; Ramluckan et al, 2014; Moreira et al, 2013). Using the Carbon Equivalent concept, in which it is measured the GWP (Global Warming Potential) of each gas, the reduced emissions of other gases that add to the aggravation of greenhouse effect may further be converted into carbon credits. This way, these generated credits can be dealt in the emissions trading market, generating profit for deployments of sustainable projects. In response to the world’s demands and the increase of researches in renewable energies that can meet the requests of the global market and to sustainable development, this present study aims to evaluate oil potential from dry biomass of Chlorella vulgaris grown in urban river wastewater attending to its feasibility for generating biodiesel

Methods

Results

Conclusion