The behavior of the pigment discoloration Permalon Rhodamine B 400% red in a liquid medium after exposure to a non-thermal plasma of different electrical power at atmospheric pressure

Abstract

The behavior of the discoloration of the pigment Permalon Rhodamine B 400% red in a liquid medium (120 mg/L) derived from exposure to a non-thermal air plasma at atmospheric pressure was quantified experimentally. Observed changes in dilution were measured as a function of plasma generation electrical power (40.0 W, 60.0 W, 80.0 W, and 100.0 W), as well as exposure time (150 minutes per power). Solution-generated effects were monitored by UV/VIS spectrophotometry measurements (absorbance; λ = 533 nm), pH, and temperature change. The absorbance of the solution increased at the beginning of the treatments to decrease after a particular time (15 minutes). The maximum effect was observed at 100.0 W (maximum power used) at minute 150; it decreased by about 2% (maximum decrease at higher power), pH by 43%, and temperature increased from 27 to 58 °C. The results showed that the change in the discoloration of the pigment in a liquid medium directly depends on the working electrical power of the plasma and the exposure time to the treatment of the solution.