Water Technology and Sciences - page 32

30
Veliz
et al
.,
Coagulation-Flocculation, Filtration and Ozonation of Wastewater for Reuse in Crop Irrigation
Water
Technology and Sciences.
Vol. VII, No. 1, January-February, 2016, pp. 17-34
Figure 9. Graphic to estimate average levels of dissolved ozone
Table 4. Average values and percentages in the reduction for each process and totals for the entire treatment scheme at a bench-
scale level. Comparison among ozone doses.
Stages/parameters
RW
C - F + F
Ozonation. O
3
doses (mg/l)
TE
(%)
40
80
160
Turbidity
UNT ± DE
312.7 ± 21.2
a
28.2 ± 8.4
b
5.7 ± 1.1
c
5.2 ± 0.8
c
5.0 ± 1.0
c
98
TDS
-
91
80
82
82
SST
mg/l ± DE
283.0 ± 19.3
a
33.6 ± 8.2
b
10.2 ± 2.8
c
9.2 ± 1.1
c
8.8 ± 0.7
c
96
R
(%)
-
88
70
73
74
Color
U Pt-Co ± DE 1 270.0 ± 90.6
a
215.2 ± 18.3
b
56.5 ± 5.6
c
51.5 ± 3.6
c
28.6 ± 4.2
d
96
R
(%)
-
83
74
76
87
Abs.
254 nm
Abs. ± DE
0.988 ± 0.103
a
0.543 ± 0.09
b
0.155 ± 0.01
c
0.137 ± 0.01
c
0.111 ± 0.01
d
84
R
(%)
-
45
71
75
80
COD
mg O
2
/L ± DE 281.3 ± 10.7
a
74.9 ± 14.6
b
41.2 ± 9.1
c
27.3 ± 6.9
c
15.6 ± 1.5
d
85
R
(%)
-
73
45
64
79
Fecal coli-
form
NMP/100 ml
± DE
8.10 ± 0.15
x 10
6a
1.22 ± 0.50
x 10
5b
830 ± 35
c
110 ± 25.0
d
0
e
99.98
R
(%)
-
98.49
99.32
99.91
100
Helminth
eggs
HH/L
4.3 ± 1.2
a
2.2 ± 0.8
b
0
c
0
c
0
c
100
SD: standard deviation.
RW: raw untreated water. Initial sample.
C-F+F: Wastewater treated with coagulation-flocculation using aluminum sulfate, dose of 100 mg/l, followed by filtration with silica sand.
O
3
doses: ozone doses applied during the ozonation stage (mg/l).
R
(%): porcentaje de reducción parcial, al compararse los valores obtenidos en cada etapa con respecto a la muestra en la etapa anterior.
ET (%): percentage in total efficiency between RW and the ozone dose of 80 mg/l.
Same letters in the superscript (for each parameter): no statistically significant differences in relation to the value of the previous sample.
Different letters in the superscript (for each parameter): statistically significant differences exist in relation to the value of the previous sample.
1...,22,23,24,25,26,27,28,29,30,31 33,34,35,36,37,38,39,40,41,42,...140
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