Wastewater-leachate treatment by microalgae: Biomass, carbohydrate and lipid production

Increases in wastewater discharges and the generation of municipal solid wastes have resulted in deleterious effects on the environment, causing eutrophication and pollution of water bodies. It is therefore necessary to investigate sustainable bioremediation alternatives. Wastewater treatment using...

Full description

Saved in:
Bibliographic Details
Published in:Ecotoxicology and environmental safety 2019-06, Vol.174, p.435-444
Main Authors: Hernández-García, Andrea, Velásquez-Orta, Sharon B., Novelo, Eberto, Yáñez-Noguez, Isaura, Monje-Ramírez, Ignacio, Orta Ledesma, María T.
Format: Article
Language:English
Subjects:
Carbohydrates
Landfill leachate
Lipids
Microalgae
Wastewater
Citations: Items that this one cites
Items that cite this one
Online Access:Get full text
Tags: Add Tag
No Tags, Be the first to tag this record!
Description
Summary:Increases in wastewater discharges and the generation of municipal solid wastes have resulted in deleterious effects on the environment, causing eutrophication and pollution of water bodies. It is therefore necessary to investigate sustainable bioremediation alternatives. Wastewater treatment using consortia of microalgae-bacteria is an attractive alternative because it allows the removal and recycling of nutrients, with the additional advantage of biomass production and its subsequent conversion into valuable by-products. The present study aims to integrate wastewater and landfill leachate treatment with the production of microalgal biomass, considering not only its valorization in terms of lipid and carbohydrate content but also the effect of nutrient limitation on biomass formation. The effect of treating a mixture of raw wastewater with different leachate ratios (0%, 7%, 10% and 15%) was investigated using a microalgae-bacteria consortium. Two microalgae (Desmodesmus spp. and Scenedesmus obliquus) were used. Nutrient removal, biomass concentration, carbohydrate, lipid and Fatty Acid Methyl Ester (FAMEs) content and morphological changes were evaluated. Removals of 82% of NH4+ and 43% of orthophosphate from a wastewater-leachate mixture (containing 167 mg/L NH4+ and 23 mg/L PO43-) were achieved. The highest final yield was obtained using Desmodesmus spp. (1.95 ± 0.3 g/L). The microalgae were observed to accumulate high lipid (20%) and carbohydrate (41%) contents under nutrient limiting conditions. The concentration of Polyunsaturated Fatty Acids (PUFAs) also increased. Morphological changes including the disintegration of coenobia were observed. By using a mixture of wastewater-leachate it is possible to remove nutrients, since microalgae tolerate high ammonia concentrations, and simultaneously increase the algal biomass concentration containing precursors to allow biofuel production. •Microalgae were able to grow in high ammonia concentrations (≥167 mg/L).•Ammonia removal of 80% using wastewater-leachate was achieved by microalgae.•The final biomass, lipids and carbohydrates obtained was 1.95 g/L, 20% and 41%.•The nutrient limitation affected microalgae morphology and FAME composition.
ISSN:0147-6513
1090-2414
DOI:10.1016/j.ecoenv.2019.02.052