production of selected secondary metabolites in transformed ...
production of selected secondary metabolites in transformed ...
production of selected secondary metabolites in transformed ...
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ε<br />
total flux [mol.m -2 ]<br />
7<br />
6<br />
5<br />
4<br />
3<br />
2<br />
1<br />
y = 0.0099x<br />
R 2 = 0.9997<br />
y = 0.0066x<br />
R 2 = 0.9983<br />
y = 0.0084x<br />
R 2 = 0.9985<br />
0<br />
0 200 400 600 800<br />
c0 [mol.m -3 ]<br />
1 day<br />
3 days<br />
5 days<br />
The results <strong>of</strong> the part which deals with the <strong>in</strong>fluence <strong>of</strong> another copper(II) solution<br />
properties shows dramatically smaller effect <strong>of</strong> the type <strong>of</strong> anion <strong>in</strong> the copper(II) salt and<br />
solution ionic strength and pH compared with <strong>in</strong>itial copper(II) concentration and time<br />
duration <strong>of</strong> diffusion. On Fig. 7, it can be seen that for all anions with unit valence (CuCl2,<br />
Cu(NO3)2 a Cu(ClO4)2) the total diffusion flux is similar even if for example anion size differs<br />
markedly. On the other hand, anions with higher valence (CuSO4 and Cu2P2O7) show<br />
<strong>in</strong>considerable decrease <strong>of</strong> total diffusion flux. The pH and ionic strength measurement<br />
excluded these properties as causer <strong>of</strong> this<br />
decrease, so it can be supposed that this shift<br />
can be expla<strong>in</strong>ed as a consequence <strong>of</strong> higher<br />
charge <strong>of</strong> multivalent anions.<br />
Total diffusion flux is also affected by the<br />
copper solution pH. Fig. 8 shows that with<br />
higher acidity <strong>of</strong> the solution total diffusion<br />
flux decreases. This could be expla<strong>in</strong>ed for<br />
example by well–known decrease <strong>of</strong> HA<br />
sorption ability <strong>in</strong> acid media (see [2]) or by<br />
the change <strong>of</strong> solution–gel equilibrium.<br />
Higher acidity affects salt hydrolysis and<br />
thus actual ion concentration <strong>in</strong> solution.<br />
total flux [mol.m -2 ]<br />
7<br />
6<br />
5<br />
4<br />
3<br />
2<br />
1<br />
y = 5.517E-03x + 2.250E+00<br />
R 2 = 9.950E-01<br />
y = 2.449E-03x + 1.343E+00<br />
R 2 = 9.994E-01<br />
y = 1.095E-03x + 3.265E-01<br />
R 2 = 9.999E-01<br />
0<br />
200 300 400 500 600 700<br />
t 1/2 [s 1/2 ]<br />
Fig. 4 The total diffusion flux dependencies on the <strong>in</strong>itial concentration <strong>of</strong> Cu 2+ and on the<br />
duration <strong>of</strong> the experiment<br />
2<br />
1.5<br />
1<br />
0.5<br />
0<br />
0 1 2 3 4 5 6<br />
τ [days]<br />
Fig. 5 The time shift <strong>of</strong> ε<br />
copper(II) ions concentration<br />
[mol/dm 3 gel]<br />
0.15<br />
0.1<br />
0.05<br />
0<br />
experimental results<br />
(0.3 M; 3 days)<br />
calculated<br />
concentration pr<strong>of</strong>ile<br />
(0.3 M; 3 days)<br />
0.1M<br />
0.3M<br />
0.6M<br />
0 10 20 30 40 50<br />
distance from the <strong>in</strong>terface [mm]<br />
Fig. 6 Concentration pr<strong>of</strong>iles <strong>of</strong> Cu 2+<br />
<strong>in</strong> humic gel<br />
total flux [mol.m –2 ]<br />
0.7<br />
0.6<br />
0.5<br />
0.4<br />
0.3<br />
0.2<br />
0.1<br />
0<br />
CuCl2<br />
0.614 0.620 0.608<br />
Cu(NO3)2<br />
Cu(ClO4)2<br />
CuSO4<br />
0.476<br />
Cu2P2O7<br />
Fig. 7 Total diffusion flux for different<br />
copper(II) salts<br />
Sborník soutěže Studentské tvůrčí č<strong>in</strong>nosti Student 2006 a doktorské soutěže O cenu děkana 2005 a 2006<br />
Sekce DSP 2006, strana 226<br />
0.355
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