Revised version of Kampai project	  joint	  meeting	   (March	  1,	  2017)	  ppt

Lead	  content	  and	  isotope	  measurements
in groundwater samples around minetailing	  area in Kabwe
A SUB-GROUP OF GROUP 3 (GSES, Hokkaido Univ.)

SHOTA NAKANOSHUNITZ TANAKAKAZUHIRO TOYODAKAWAWA BANDA (UNZA)GROUND WATER SAMPLING SITES (2016 JULY)WATER SAMPLING SITES （2016 JULY）
F2●

S2●
Makululu

Central

●T2
W2

D1●

D2W8●●
●
●
●
W6 ●

W9●
●

W10

W5W14

W7

W13W3●●
W1●
●
W4●
W11●
W12

P2P3Kasanda●B2Railway●F1●

B3●
B1Waste	  tailingsMining	  area

W15 ●P1Katondo

W16●Chowa

S1 ●

●

W17

●Shallow   well  (hand  dig   well)●Deep  well  (hand  pump  well)●Bore  hole
●Pond●Water  treatment  plant●Tap  water●SoilONLY two Soil  sampling  by  Dr.  Nakayama：2015,  October
Map  o f  around  mining  area    and  sampling  p oints  o f  water  sample  in  Kabwe,  Z ambia  ●Chemical	  analysis
1. Filtered	  water	  samples:à pH	  and	  ion	  chromatogram	  measurements	  (Cl-­‐,	  NO3-­‐,	  SO42-­‐,	  etc.)
2. Filtered (0.45	  µm	  pore	  size)	  and	  acid-­‐added	  water	  samples	  (final	  0.4	  M	  HNO3 soln.):à Dissolved Pb concentration	  and	  Pb isotopic	  ratios	  measurement	  by	  ICP-­‐QMS
à Major	  cation measurements	  (Na+,	  K+,	  Ca2+,	  Mg2+,	  etc.)	  by	  ICP-­‐OES
3. Unfiltered acid-­‐added	  (final	  0.7	  M	  HNO3 soln.)	  and then	  incubated	  at	  80˚C	  during	  two	  days	  for	  digestion	  of	  suspended	  mater	  in	  water	  samples à Particulate	  (+dissolved)	  Pb concentration	  and	  Pbisotopic	  ratio	  measurement	  by	  ICP-­‐QMS140

Chemical	  composition	  of	  filtered	  water	  samples (2016	  JULY)

120

100Ca (ppm)

Carbonate dissolution
80

60

40
T2, F1, F2, D1, D2
Deep layer, tap water

200

W15
W140

20

40

6080

Mg (ppm)

100120140

Chemical  composition  of  filtered  water  samples  (2016  JULY)

12500

W11W3, W4,W8, W11

10Mica dissolution

P2, 3SO2-640

Sulfate dissolution
from mining area200

P1, B1, B2, B3T2, F1, F2,D1, D2
2300

4(ppm)

8K (ppm)

400

100

W14W3, W4, W17

W15051015Na (ppm)

20

2530

00204060

80

Ca (ppm)

100

120

140

Chemical  composition  of  filtered  water  samples  (2016  JULY)

80

80

70

70
W1, 2, 1360
W7-

40
30
2040
30
20

10P1050

3NO (ppm)

503NO-(ppm)

60

0100

10
B1, 2, 3200

SOP2,3300

2-4(ppm)

400

W11P2,3
500

00

10W3, 4,11B2

20

30
-

Cl (ppm)

4050

60

Dissolved Pb concentration (ppb)100
shallow Wall
Bore hole
Pond
Plant & Tap

10Mining area

1Tap water:
Pb plumbing?

0.1
Deep groudwater
W80.01
0.1

1

10

100

1000

Particulate + dissolved Pb concentration (ppb)2.15

Lead	  isotope	  ratios	  of	  particulate	  Lead	  (>	  5	  ppb)	  in	  water	  samples

Galena(PbS)	  from	  m ining	  area	  (Kamona 1999)

Soil 3km	  away	  from	  m ining	  area	  (Pb :	  263	  ppm)	  S22.14208 Pb/ 206 Pb

2.13

2.12

Soil	  adjacent	  in	  m ining	  area	  (Pb :	  2693	  ppm)	  S12.11Just  after  an  artificial  chemical  input

2.1

2.09

2.08
0.845

Only  site  in  Shist area

0.85

0.855

0.860.865
207 Pb/ 206 Pb

0.87

0.875

0.88

Discussion 1• In	  pond	   and	   bore-­‐hole	   water	  samples	   from	  the	  mining	  area,	  1-­‐20	  ppb	   of	   dissolved	   Pbconcentration	  (<0.45	  µm)	  are	  found.	  This	  indicates	   the	   possibility	  of	   colloid-­‐facilitated	  transport	  of	  heavy	   metals	  from	  the	   mining	  area	  to	  shallow	   and/or	   deep	  aquifers	  in	  near	  future.
• Low	  dissolved	  Pb concentrations	  (<	   0.1	  ppb)	   are	  found	  in	  all	   shallow	  and	   deep	   well	   water	  samples	   and	  these	  are	  too	   low	  for	   Pb isotopic	  measurements.	   This	  might	  be	   due	   to	  relatively	  high	  pH	   (7.8–8.3)	  and	  hardness	   of	   the	   ground	  waters	  in	   the	   dolomite	   area.	  Discussion 2• Two	  interpretations	  for	   the	  consistency	  in	  Pbisotopic	  ratios	  between	  mining	  area	   and	  particulate	  Pb in	  shallow	  well	  water	  samples	  are	  probable:	  1)	  migration	  of	  Pb from	  the	  mining	  area	  by	  the	  colloid-­‐facilitated	  transportation;	  2)	  A	  similarity	  in	  Pb isotopic	  ratios	  between	  mining	  area	  and	  the	  dolomite	  area	   where	  the	  sampling	  sites	  distributes.
• Relative	  high	  particulate	  Pb concentration	  (1–100	  ppb)	  in	  shallow	  well	  water	  samples	  may	  be	  due	  to	  the	  high	  contents	  of	  suspended	  maters,	   e.g.,	  clay,	  in	  the	  water	  samples. Usually, sediment	  contains	  several	  ppm	  of	  Pb.	  Required	  supplementary	  measurements• Estimation	  of	  suspended	  mater	  contents	  by	  major	   element (Si, Al, Fe etc.)	  determination	  of	  the	  digested	  water	  samples.
• Pb isotopic	  measurements	  of	  some	  background	  geological	  samples	  anterior	  to	  the	  mining	  activity.	  
• The	  other	  heavy	  metal	  elements	  (e.g.,	  Zn,	  Cd,	  Cu,	  Co,	   etc.)	  measurements	  in	  these	  water	  samples.
We	  would	  like	  to	  submit	  the	  results	  for	  publication	  in	  an	  academic	  journal	  in	  collaboration	  with	  Prof.	  Nyambe and	  Dr.	  Banda	  so	  soon.