Pollution of natural waters has become a major issue all over the world. As a result, scientists are studying new and alternative technologies not only to identify the presence of different pollutants in the environments but to remove them from waters and industrial effluents. In these senses, in recent years various red, green and brown seaweeds were investigated as potential bioindicators of contaminants inthe environment; as well as their use in remediation process. The green marine macroalga, Ulva lactuca (Chlorophyta) is very common at coastal areas, and is a bloom forming macroalgae that occur in shallow estuaries. This specie has a high bonding affinity with heavy metals and several organic compounds due to the presence of different functional groups on its cell walls (such as carboxyl, hydroxyl, phosphate or amine) that can bind metal and/or organic ions. These characteristics makes it suitable to be used as a bioindicator of marine pollution and for remediation purposes. In general, the investigations are focused on the application of dried algae biomass to promote the removal of different contaminants, mainly metals from aqueous solutions (biosorption); however, the use of living organisms (bioaccumulation), may be advantageous. While growing, living macroalgae can remove simultaneously pollutants and nutrients (nitrates and phosphates) from wastewaters and capture CO2 emissions. In this context, the present chapter will conduct a comprehensive inquiry on the advances related to the possibility of Ulva lactuca to be used as a bioindicator of contamination as well as its capability to be employed for the removal of pollutants from the surrounding environment. It will review these different approaches, and analyse the advantages and disadvantages of each as exposed on the literature, as well as the challenges that these alternatives confront as sustainable remediations technologies.

Fil: Salomone, Vanesa Natalia. Universidad Nacional de San Martín. Instituto de Investigación e Ingeniería Ambiental. - Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Instituto de Investigación e Ingeniería Ambiental; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Química, Física de los Materiales, Medioambiente y Energía. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Química, Física de los Materiales, Medioambiente y Energía; Argentina

Fil: Areco, María del Mar. Universidad Nacional de San Martín. Instituto de Investigación e Ingeniería Ambiental. - Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Instituto de Investigación e Ingeniería Ambiental; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Química, Física de los Materiales, Medioambiente y Energía. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Química, Física de los Materiales, Medioambiente y Energía; Argentina

Fil: Dos Santos Afonso, María. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Química, Física de los Materiales, Medioambiente y Energía. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Química, Física de los Materiales, Medioambiente y Energía; Argentina