Effects of Biochars from Different Feed Stocks on
Wastewater N and P Adsorption
H. Ren1, Q. Wang1*, Y. Li1, A.K.Alva2, B.Gao3
1 University of Florida, TREC-Homestead, 3Department of ABE-Gainesville, FL , and 2USDA-ARS, Prosser, WA
INTRODUCTION
(N, P)ads > 0: Net adsorption; and < 0: Net desorption.
Reducing rate  ( C i  C e ) / C i  100%
Ci > Ce net adsorption occurs, Ci < Ce net desorption occurs.
RESULTS
-N a d s o rp tio n ra te (m g N /k g )
D yn a m o tiv e
H a rd w o o d
P e a n u t h u ll
B agasse
A c tiv a te d c a rb o n
1000
500
0
4
Five Char Type treatments with 3 replications:
Dynamotive Canada (Commercial Biochar), Peanut Hull, Bagasse,
Hardwood, Activated Carbon (CK)
Treated with 7-Char Rates (ratio of biochar : water):
0 g, 0.1 g, 0.2 g, 0.4 g, 1 g, 2 g and 4 g in 40 ml wastewater. The
wastewater sample used in this experiment was collected from the
municipal wastewater treatment facility at Tropical Research and
Education Center, University of Florida, Homestead, FL. The above
mixtures in 60 ml polypropylene tubes were shaken at 100 rpm for 24 h.
Table 1 Concentrations of elements in the wastewater (mg/L)
Ortho-P
NH4+-N
NO3--N
F-
Cl-
SO42-
Br-
1.94±0.07
24.40±0.96
0.00±0.00
0.40±0.13
147.21±3.15
27.15±0.58
2.56±0.96
-5 0 0
0
0 .2 0 .4
1 .0
2 .0
Fig. 1 NH4+-N adsorption with different biochar rates and types
Table 3 NH4+-N reduction rate of different biochars to wastewater ratios
Biochar rate
g/40 ml wastewater
0.0
0.1
0.2
0.4
1.0
2.0
4.0
Dynamotive
Hardwood
0.0
7.5
10.1
22.1
42.9
64.1
80.4
0.0
5.8
16.8
33.6
72.0
58.1
18.6
Peanut hull
%
0.0
3.9
4.9
14.5
28.9
45.0
65.8
Peanut Hull
Bagasse
Activated
Carbon
Processing
temperature (℃)
400-450
400
600
300
—
NH4+-N (mg/L)
0.277±0.044
0.260±0.031
0.182±0.021
0.386±0.032
1.020±0.537
NO3--N (mg/L)
0.044±0.002
0.015±0.015
0.013±0.002
0.059±0.019
0.058±0.051
Ortho-P (mg/L)
0.221±0.046
0.119±0.017
4.737±0.131
0.079±0.006
0.036±0.046
The result was obtained by adding 1 g of biochar to 40 ml DDI water in a 60 ml polymeric tube, shaken for
24 hour at a speed of 100 rpm, and analyzed as other samples.
( N , P ) ads  [ C ( N , P ) i  C ( N , P ) e ]  V wastewater / m biochar
( N , P ) ads -N or P adsorbed by biochar
-Initial concentration of N or P in wastewater
C ( N , P ) e -N or P concentration after 24 hours shaken
V wastewater -Volume (ml) of wastewater
m biochar -Weight (g) of biochar in the tube
C ( N , P )i
Bagasse
Activated carbon
0.0
12.5
23.1
44.4
63.1
0.8
13.0
0.0
-3.3
-4.2
-4.8
4.0
11.7
35.6
800
O rth o -P a d s o rp tio n ra te (m g P /k g )
Hardwood
4 .0
B io c h a r ra te (g /4 0 m l w a s te w a te r)
Table 2 Properties of different biochar types and activated carbon
Dynamotive
Dynamotive
Hardwood
Peanut hull
%
Bagasse
Activated carbon
0.0
0.0
0.0
0.0
0.0
0.0
0.1
17.5
46.0
-16.3
79.1
-1.3
0.2
19.6
72.0
-31.6
98.1
1.3
0.4
46.3
95.6
-47.6
98.1
5.8
1.0
79.1
89.1
-42.3
95.1
22.0
2.0
87.3
93.7
-42.6
94.6
41.3
4.0
78.7
91.8
-96.6
86.0
59.9
CONCLUSIONS
NH
MATERIALS AND METHODS
Biochar rate
g/40 ml wastewater
1500
+
Wastewater from industrial, agricultural and municipal sources is
usually hazardous to human beings and the environment, if disposed
inappropriately. Biochar produced from slow pyrolysis for bio-fuel has
potential adsorption of heavy metals and harmful organic compounds in
wastewater and soil, such as lead (Mohan et al., 2007; Cao et al., 2009;
Liu and Zhang, 2009), arsenic (Mohan et al., 2007), cadmium (Mohan
et al., 2007), naphthalene, 1-naphthol (Chen and Chen, 2009), atrazine
(Cao et al., 2009) and dye (Qiu et al., 2009). Phosphorous (Mortula et
al., 2007), copper and zinc (Wilson et al., 2002), and some macro- and
micro-nutrients, can also be absorbed by biochar. This study compared
the adsorption of N and P in municipal wastewater by application of 4
biochars produced from different feed stocks: a commercial biochar
(Dynamotive Canada), Peanut Hull, Bagasse and Hardwood compared
to commercially activated carbon as a control.
Table 4 Ortho-P reducing rate of different material to solution rate of different biochar types
REFERENCES
D yn a m o tive
H a rd w o o d
P e a n u t h u ll
B agasse
A c tiva te d c a rb o n
600
400
200
0
-2 0 0
0
0 .2 0 .4
1 .0
2 .0
B io c h a r ra te (g /4 0 m l w a s te w a te r)
Fig. 2 Ortho-P adsorption with different biochar rates and types
•NH4+-N adsorption by application of biochars made from
Dynamotive and peanut hull increased significantly with the
biochar rate, while that of activated carbon did not show any
increase until the rate of 1:100 (0.4 g /40 ml wastewater).
•The adsorption of bagasse and hardwood increased from the rate
of 1:400 (0.1 g /40 ml wastewater) and decreased from the rates of
1:40 (1 g /40 ml wastewater) to 1:10 (4 g /40 ml wastewater)
significantly.
•The ortho-P adsorption by biochars from Dynamotive,
hardwood, bagasse and activated carbon increased with
application rates and these materials follow the order of bagasse >
hardwood > Dynamotive > activated carbon. The peanut hull was
found releasing P significantly to the wastewater.
•The highest NH4+-N and ortho-P decreased in the wastewater by
biochars reached up to 80.4% and 98.1%, which showed a great
potential being used as wastewater treatment materials.
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