232
C. De Stefano . C. Foti . A. Gianguzza . D. Piazzese . S. Sammartano
Fig. 9.4. Speciation diagram of
100 " - - - - - - - - - - - - - - - - - - - - - - ,
tca in artificial sea water singlesalt (S = 35, t= 25 °C);
CBA = 0.5752 mol rl;
C tc .= 10- 4 moll-I.
Curves: 1. B(tca)H2; 2. B(tca)H;
3· B(tca); 4· B2(tca); S.lspecies%
Fig. 9.5. Sum of species percentages vs. salinity (S) of carboxylic ligands in SSWE as
single salt, at pH = 8.2
Table 9.8. Formation constant
'j
~ 50
c?.!
100
[ 50
~
5
3
4
5
8
pH
----b-- tea
-V- bte
\ 1 - \ 1 - - \ 1 -
/", ___ ,, __ Z==E
, , / ~ ________ O _____ O--O
0/0 _ _ _ 0 - - - 0
.___0---- 0
-D-- ac
0""""""'--0- mala
O+I----~--_r----~--_,--~~--,,~
o
15
30
45
5
for phenol complexes with Bl. ll7 + Ligand
(1= 0 molr l ; t= 25 °C)
logK a
phenol
o-cresol
p-cresol
o-nitrophenol
p-nitrophenol
Mean value
0.3
0.1
0.3
0.2
-0.1
0.15
a K refers to the reaction: B + L H BL.
very similar to that of the humic water-soluble fraction. Therefore, polyamines can be
considered as a representative model of aminic sites in the humic acids, whose NMR