commercial sorbent GEH, we achieved as low arsenic concentration in the
remediated water as with ferrates—1.7 mg/L. By means of coagulation tests, we
achieved the lowest concentration of As in the output water for coagulant FeCl 3 and
the dose of Fe 190 mg/L (1.2 mg/L and pH 9.5); Al (PAX-18)-based coagulant
achieved only minimal efficiency (As in the output water 1.9 mg/L).
Table 13.9 Phosphorus—effect on arsenic removal from water
ALS laboratory chemical
analysis
Phosphorus limits
As removal
Site SFA
Site KLU
Parameter
Unit
SFA
INPUT
SFA OUTPUT
UF 60 mg/L
KLU
INPUT
KLU OUTPUT
UF 15 mg/L
Dissolved solids dried at
105
C
mg/
L
4570
–
428
437
Chemical oxygen
demand (COD-Mn)
mg/
L
4.10
–
0.71
0.84
Chloride
mg/
L
114
–
23.0
31.3
Fluoride
mg/
L
23.4
–
<0.200
<0.200
Hydrogen carbonates
HCO 3
À
mg/
L
615
–
96.2
86.3
Nitrates
mg/
L
35.3
–
88.8
88.1
Orthophosphate
mg/
L
1590
–
0.157
<0.040
Sulfate as SO 4
2À
mg/
L
423
–
53.4
53.5
Electrical conductivity at
25
C
mS/
m
423
–
50.6
51.9
pH value
–
6.54
6.56
7.44
7.25
Arsenic
mg/
L
2.5
1.73
0.102
<0.0050
Calcium
mg/
L
36.1
–
56.8
61.2
Iron
mg/
L
<0.0200 0.234
0.0035
0.0746
Magnesium
mg/
L
25.9
–
13.8
14.9
Manganese
mg/
L
0.184
–
0.00631 0.00780
Phosphorus
mg/
L
988
823
0.098
<0.040
Potassium
mg/
L
27.2
–
2.50
9.85
Sodium
mg/
L
1450
–
15.0
16.4
The bold entries mark the key parameters influencing the efficiency of ferrates in arsenic removal
312
M. Heřmánková et al.