Biomedical Engineering Reference
In-Depth Information
Table 4. Effect of Cr(VI) addition on the production of metabolites (expressed as
dissolved organic carbon, DOC) by the algal cells
Concentration of Cr(VI) (mg l
-1
)
Microalgae
0
1
5
25 (50 for
CF
)
Metabolites (DOC average ± standard deviation)
(mg l
-1
)
Chlorella fusca (CP)
11.0±4.9
8.0±4.1
8.9±3.9
16.2±6.7
Chlorella vulgaris
29.1±9.7
26.8±5.3
24.6±1.0
24.2±2.4
Scenedesmus acutus
29.2±4.3
40.9±29.6
38.4±34.6
28.9±5.2
Scenedesmus obliquus
26.2±3.7
28.3±8.6
35.3±21.8
26.2±2.6
160
160
SB=0.447×BC
R
2
=0.880
SB=0.530×BC
R
2
=0.981
140
140
120
120
100
100
Chlorella Fusca
Chlorella Vulgaris
80
80
60
60
40
0 mg Cr/l
1 mg Cr/l
5 mg Cr/l
50 mg Cr/l
40
0 mg Cr/l
1 mg Cr/l
5 mg Cr/l
25 mg Cr/l
20
20
0
0
0
50
100
150
200
250
300
0
50
100
150
200
Biomass concentration
(mg l
-1
)
Biomass concentration
(mg l
-1
)
160
160
SB=0.293×BC
R
2
=0.925
SB=0.410×BC
R
2
=0.946
140
140
120
120
Scenedesmus Obliquus
Scenedesmus Acutus
100
100
80
80
60
60
0 mg Cr/l
1 mg Cr/l
5 mg Cr/l
25 mg Cr/l
40
0 mg Cr/l
1 mg Cr/l
5 mg Cr/l
25 mg Cr/l
40
20
20
0
0
0
50
100
150
200
250
300
350
0
100
200
300
400
500
Biomass concentration
(mg l
-1
)
Biomass concentration
(mg l
-1
)
Figure 7. Suspended biomass as a function of dry biomass concentration. (—) Linear regression. SB =
Suspended Biomass; BC = Biomass Concentration.
Suspended organic carbon was plotted against biomass for each Cr(VI) concentration and
no significant dependence on Cr(VI) was observed. A global linear correlation between
biomass concentration and suspended organic carbon for each algal culture was found, as
