Biosorbent Efficacy of Groundnut Husk for the Elimination of Chromium from the Effluent of Mojo Tannery Industry, Ethiopia
Table 3
The effect of biosorbent dose, contact time, and agitation speed on chromium removal from tannery wastewater effluents.
Trt
Biosorbent dose (gm)
Initial concentration of Cr (mg/L)
Percentage removal of Cr
Agitation speed (rpm)
Percentage removal of Cr
Contact time (h)
Percentage removal of Cr
R
1.00
12.25a
28.68h
80.00
67.73b
1.00
39.06j
EE
1.00
12.25a
21.62i
80.00
20.11h
1.00
40.93i
AT
1.00
12.25a
67.73d
80.00
45.01ef
1.00
94.41a
R
2.00
12.25a
45.01g
120.00
60.08c
2.00
45.01h
EE
2.00
12.25a
43.94g
120.00
36.75g
2.00
43.94h
AT
2.00
12.25a
89.93a
120.00
47.63e
2.00
89.85b
R
3.00
12.25a
68.44d
160.00
46.21ef
3.00
56.39e
EE
3.00
12.25a
65.43e
160.00
44.34f
3.00
53.26f
AT
3.00
12.25a
85.84b
160.00
43.78f
3.00
80.61d
R
4.00
12.25a
91.03a
200.00
89.43a
4.00
53.18f
EE
4.00
12.25a
60.24f
200.00
53.44d
4.00
48.69g
AT
4.00
12.25a
83.27c
200.00
52.76d
4.00
84.78c
Means followed by same letter within a column were not significantly different at 0.05 probability level based on the LSD (least significance difference) test. R, powdered raw/untreated groundnut husk; EE, ethanol-extracted biosorbent; AT, acid-treated biosorbent.
