RT info:eu-repo/semantics/masterThesis
T1 Factors influencing the bioremoval of copper and zinc from wastewater using microalgae, bacteria, and their consortia
A1 Moldes Plaza, David
A2 Universidad de Valladolid. Facultad de Ciencias
K1 Bioeliminación
K1 Metales pesados
K1 Microalgas
K1 Bioremediación
AB Water pollution by toxic heavy metals is a severe socio-sanitary problem that requires efficient, environmentally friendly, and economically viable solutions.Typical pig diets have a high content of phytates, which reduces the availability of Zn and Cu. Thus, to ensure animal health, welfare and productivity, pig diets are supplemented with these elements that are partially released to the ambient through the urine and feces. These residues represent an alarming problem nowadays, due to their high concentrations of carbon, nitrogen, phosphorous, and, of course, heavy metals and pharmaceutical products. Therefore, it is essential to develop an effective treatment of slurry generated in livestock facilities, which not only prevents contamination but also allows the recovery of organic matter and nutrients present in them, applying the concept of circular bioeconomy.This work aims to provide a sustainable solution to this issue, using microorganisms to treat and valorize wastewater from the food industry, in general, and livestock, in particular. The study focuses on the elimination of two metals (Cu and Zn) that, although essential at low concentrations, can be toxic when prolonged exposure to concentrations higher than required takes place.A bibliographic review has been carried out to evaluate the retention capacity of these elements by microalgae, bacteria, and their consortia, the experimental conditions in which metal retention takes place, and the predominant bioaccumulation mechanisms in each type of biomass.In the experimental part, a complete factorial design of 144 experiments has been applied to evaluate the effect of six factors on the bioelimination capacity of copper and zinc and the growth of the biomass. Three types of biomass were used: a pure Scenedesmus Almeriensis strain, a bacterial sludge, and a consortium of Scenedesmus Almeriensis and bacteria grown in slurry water. Furthermore, we selected other factors intending to study whether they influenced the retention process or not, such as organic matter, the CO2, the initial concentration of metals, the light, and the contact time.After the statistical analysis of the results, it was determined that the most important factors are the type of biomass (the pure microalgae showed the highest metal retention capacities), the initial metal concentration (the higher the concentration, the higher the retention), and stirring time (short times resulted in higher retention). For pure microalgae and slurry-grown biomass, significant biomass growth was observed.The results obtained from the retention capacities are promising since very high values were reached for copper and zinc metals, which makes it possible to consider the treatment of wastewater with high organic load and metals in photobioreactors as a promising method for the elimination heavy metal.
YR 2020
FD 2020
LK http://uvadoc.uva.es/handle/10324/43307
UL http://uvadoc.uva.es/handle/10324/43307
LA eng
NO Departamento de Química Analítica
DS UVaDOC
RD 03-jun-2024