HCl, FeCl2, CuCl2 PBrDPE

1
DETECTION OF Co-PCB IN THE FeCl3 MANUFACTURING
PROCESS Takeshi Nakano, Chisato Matsumura,
Masahiro Tsurukawa, and Yuzo Moriguchi Hyogo
Prefectural Institute of Public Health and
Environmental Sciences, 3-1-27 Yukihira-cho,
Suma-ku, Kobe, 654-0037 Japan
FeCl3 as coagulantCoprecipitation involves
removal of two or more constituents by a
precipitation reaction. Coprecipitation of
element with Fe(OH)3 is an effective treatment
process FeCl3 3H2O Fe(OH)3 3H 3Cl-
PCB concentrations in waste water treatment
system.
FeCl3 as etching liquidFerric Chloride
(FeCl3) is used to etch away copper that isn't
protected by the remaining photoresist coating on
the PC board (Printed circuit board). To recover
copper and nickel from a spent FeCl3 etching
solution, these chemicals are recycled.
Figure GC/MS chromatogram in contaminated FeCl3
(Co-PCB 126)
FeCl3 manufacturing process.
Figure GC/MS chromatogram in contaminated FeCl3
(Co-PCB 169)
FeCl3 manufacturing process and metal recovery
process .
Results and Discussion Figure 1 shows the
GC/MS-SIM chromatogram of the contaminated liquid
FeCl3. Monobromo 126, 169 and 189 were
detected. PCB concentration was 126 gt 169 gt
189. The relative concentrations of monobromo
compounds that replaced Cl with Br was 126 ?
169 gt 189. Figure 2 is the GC/MS-SIM
chromatogram of Co-PXB. The concentration level
was 126 (PeCB) gt 126 (MBrTeCB) gt 126
(DiBrTrCB), and Tribromo, Tetrabromo and others
were not detected. Among MBrTeCB
3,3,4,4,5-monobromo-tetrachloro biphenyl, only
4'-bromo- 3,3',4,5-tetrachloro biphenyl is
commercially available. In Figure 2, 126
(MBrTeCB) was proposed to be 3'-bromo-3,4,4',5-te
trachloro biphenyl, 3'-bromo-3,4,4',5'-tetrachloro
biphenyl, or 4'-bromo- 3,3',4,5'-tetrachloro
biphenyl. Figure 3 shows the results of
fluorescent X-ray analysis on used etching
liquid, liquid FeCl2 and liquid FeCl3. The used
etching liquid was found to contain a high
concentration of Cu and a trace of Br in addition
to Fe and Cl. The major PCB congeners in the
contaminated liquid FeCl3 were 3,3',4,4',5-PeCB
(126), 3,3',4,4',5,5'-HxCB (169). In the
manufacturing process, metal iron is added to
used etching liquid (FeCl2 and FeCl3) and recover
Cu and Ni. The used etching liquid is then
recycled by blowing chlorine into the reduced
FeCl2. In the past, the printed circuit boards
contained brominated flame retardant
(tetra-bromo-bisphenol-A, PBrDPE) and epoxides of
Tetrabromobisphenol-A (glycidyl-ether of phenolic
OH group) were used. The existence of brominated
compounds is predicted such as epoxide of
Tetrabromobisphenol-A in used etching liquid.
Etching liquid contains CuCl2 and brominated
compounds, and has extremely low pH
Figure 2 GC/MS chromatogram in contaminated
FeCl3 Co-PXB 126(PeCB, MBrTeCB, DiBrTrCB)
Figure 1 GC/MS chromatogram in contaminated FeCl3
Co-PXB 126,169,189(monobromo substituted)
HCl, FeCl2, CuCl2 PBrDPE
Figure 4 PBrDPE in strongly acidic solution in
presence of HCl, FeCl2 and CuCl2.
Figure 5 TEQ contributions () of co-PCB in FeCl3
Unique distributions of major PCB congeners from
3,3-dichloro benzidine related sites.
Figure 3 Fluorescent X-ray analysis of liquid
samples (A) used etching waste, (B) FeCl2, (C)
FeCl3
Figure 6 Distributions of 3, 3, 4, 4, 5-PeXB in
FeCl3.
Figure 7 tetra-, penta-, hexa-, and hepta-XB. in
FeCl3