Short Study about Removing the Black Crust formed by the Influence of SO2, NOX, CO2 on Saint Michael’s Church Masonry in Cluj-Napoca, Romania, by Chemical and Physical Methods
Elena Maria Pica, Ioana Popister, Zuzana Slížková & Valer Micle
A short study of the SO2, NOx, CO2 influence on cultural heritage, as in the case of Sf. Michael's Church Masonry in Cluj-Napoca, Romania is presented; special attention is given to the black crust formation. The composition of the black crust was determined;the black crust was then cleaned with the laser-based chemical method and with the physical method of cellulose plaster soaked in
ammonium hydrogen carbonates [NH4 (HCO3)].