Recently, the awareness of the need for compatible materials to be used to preserve the architectural heritage has increased, which has led to an increase in the revival of lime-based mortar technology and its applications. However, it is known that the preparation process and procedures affecting the final quality of lime slurry are limited, and there is no doubt that there is still debate in the preservation community as to the most suitable material for preservation treatments (for example, slaked lime versus aged lime putty).
It is known to everyone interested in studying the restoration of ancient buildings that some problems are resulting from the growth of microorganisms, for example, bacteria and fungi.
Metal oxide nanoparticles (NPS), sometimes called engineered
nanoparticles, have been used to protect building surfaces against
biofilm formation for many years, but their lifespan in the
cultural heritage world is short. Its first use was in 2010.
Subsequently, it has had a wealth of reports in the literature, with
Ti, Ag, and zinc oxides being the main heroes. In all surface
treatments, NPs can leach into the surrounding environment,
resulting in potential environmental toxicity to soil, water, and
associated organisms. It is important to us that the testing of the
biocidal products used for this is updated, as well as that of a
standardized antimicrobial test. Highly efficient to determine
their impact on the environmental processes of non-target
surrounding organisms and their transformation.