RT info:eu-repo/semantics/doctoralThesis T1 Elucidation of heavy metal removal, transformation and distribution mechanisms in piggery wastewater treatment systems with microalgae and activated sludge A1 Antolín Puebla, Beatriz A2 Universidad de Valladolid. Escuela de Doctorado K1 Purines K1 Piggery wastewater K1 Agua residual porcina K1 Heavy metals K1 Metales pesados K1 Microalgae K1 Microalga K1 Activated sludge K1 Fango Activo K1 2391 Química Ambiental AB Pig manure management has become one of the biggest environmental challenges in recent years due to the increasing production of pork for human consumption. Manure is a liquid mixture of pig excrement, water, and in some cases, chemicals used in cleaning facilities. This by-product of pig production can be a source of contamination if not properly managed. One of the major problems associated with this waste is its high nutrient content, due to high loads of N, P and organic matter. Proper management is therefore necessary, as once they are discharged into the environment, they can generate problems of pollution and eutrophication of water, negatively affecting aquatic ecosystems. On the other hand, the use of mineral additives in livestock feed, and other supplements used as growth promoters, means that 90% of the heavy metals they contain pass into the manure, with only 10% being assimilated by the animal. In addition, drinking water is another key factor and source of metals entering the livestock diet.Biological processes with microalgae and bacteria have gained importance in recent years due to their high effectiveness and low cost. Moreover, it is an environmentally sustainable, robust technology that simultaneously removes organic matter, nutrients and pollutants (heavy metals) and does not generate toxic waste. The biomass generated is a consortium of microalgae and bacteria, which can be subsequently valorised as feed or fertiliser, provided that the bioaccumulated metals are not present in the recovered by-products or are within the limits permitted according to their use. The treated water can be reused as irrigation water. Therefore, in this work, the use of live microalgae and their consortia with bacteria was studied in order to study the bioelimination of toxic trace elements present in the liquid fraction of pig manure. Specifically, the efficacy of the microalgae species Scenedesmus almeriensis in the bioelimination of Cu, Zn and As, among others found in lower concentrations such as Cd, Pb, Hg and U, was evaluated.This thesis constitutes a first approach to wastewater treatment combining the removal of nutrients and heavy metals with microalgae and activated sludge, as well as the effect of these pollutants on the viability of the biomass grown. YR 2024 FD 2024 LK https://uvadoc.uva.es/handle/10324/69379 UL https://uvadoc.uva.es/handle/10324/69379 LA eng NO Escuela de Doctorado DS UVaDOC RD 01-sep-2024