3.2.2. Effect of initial concentration on the removal of TC
The variation trends of TC destruction at different initial concentrations
were indicated in Fig. 7. It was illustrated that the TC
degradation rate was decreased with the increased initial concentration
in plasma-TiO2 system. With different initial concentrations
of 25 mg L1, 50mgL1 and 100 mg L1, the removal rates
of TC reached 98.7%, 77.9% and 59.1% in discharge plasma, whereas
only 82.1%, 61.9% and 45.7% in single plasma conditions. It could be
concluded that the efficiency and velocity of TC degradation were
greatly affected by the initial concentration. Obviously, the higher
removal rate needed longer time, and the reactive potentiality
tended to equilibration with the constant natural conditions. The
effective contact probability with objective molecules increased,
but the degradation efficiency distorted a descending trend due
to the incompetent supply of active species. Furthermore, the catalytic
effect of TC removal showed an imperceptible fluctuation
compared with others, the results indicated that the special characteristics
and mechanism of TiO2 catalyst would make a needless
interference with the initial concentration of TC [21].