The study tested the growth responses of three bamboo species (Bambusa vulgaris, Dendrocalamus giganteus, and Bambusa X) to wastewater irrigation, finding that plants receiving wastewater had higher assimilation, leaf area, chlorophyll content, and biomass accumulation compared to those receiving only clean water, supporting the hypothesis that bamboo can effectively uptake nutrients from wastewater through increased growth.

1. Utilization of Bamboo in Fixing
Biomass From Wastewater
Progress Report By
Hunja Murage
Supervisors: Prof. C. Ong, Dr.K. Ngamau,
Dr. C. Muthuri

2. Introduction 1
Water pollution is a major problem in
Kenya.
Effluent from industries and human
settlements is the main source of the
problem.
Rural urban migration has given pollution
an urban focus.
Effluent finds its way into the water supply:
both surface and ground water.

3. Introduction 2
The forest cover in Kenya is under siege,
because of increased need for settlement,
farmland and forest products.
Bamboo can, while providing a substitute
for wood, because of its water pumping
properties, be useful in fixing biomass
from wastewater.
Wastewater from urban areas is not suited
to growing food crops due to pollutants.

4. Objectives
• To test bamboo species for their utility in
wastewater treatment.
• To test the tolerance of these bamboo
species to high nutrient conditions.

5. Hypotheses
Different bamboo species respond to
wastewater by taking up nutrients and
increase leaf area.
Water use efficiency will remain relatively
similar between species
Wastewater has little impact on water use
efficiency

6. Materials & Methods
3 bamboo species, Bambusa vulgaris,
Dendrocalamus giganteus, and Bambusa
X were used in this study.
They were grown in 100 litre pots at the
JKUAT experimental farm, in a
randomized complete block design.
Wastewater from the University treatment
ponds was used to irrigate the plants

7. Materials & Methods
Growth parameters such as plant height,
leaf number, number of branches, collar
diameter were taken at monthly intervals.
Infra Red Gas Analyzer was used to
measure assimilation, evaporation and
stomatal conductance twice a week.
Measures of chlorophyll content were also
taken using SPAD, and soil moisture
levels monitored with a moisture metre.

8. Bamboo Wastewater Trial in Juja

9. Constitution of Juja wastewater
Cu (mg/kg)Ni (mg/kg) Cd (mg/kg)Pb (mg/kg)Zn (mg/kg)K (mg/kg) Na (mg/kg)
0.6 0.7 0.2 1.0 7.6 542.6 962.1
TOC (mg/l) TC (mg/l) IC (mg/l) P (µg/l)
5.8 37.9 32.1 70.9
TOC = Total Organic Carbon TC = Total Carbon IC = Inorganic Carbon
The levels of K and Na are very high.
This would have an effect in the opening and closing
of stomata.

10. Diurnal A for 3 Bamboo species
12
10
8
A (um/m2/
6
4
2
0
0 2 4 6 8
Hours (from 8am)
The diurnal assimilation trend for the 3 bamboo
species is the same.
The plants receiving wastewater (red) have higher
levels of assimilation than clean water (black).

11. Diurnal Stomatal Conductance for 3 Bamboo Species
300
Stomatal Conductan
(milimoles/m2/s)
250
200
150
100
50
0
0 1 2 3 4 5 6 7 8
Hours (from 8am)
The diurnal stomatal conductance trend for the 3 bamboo
species is the same.
This supports the data on diurnal assimilation.

12. Water Use Efficiency
14
12
giant
10
A(um/ms2/
8
6
4
2
0
0 1 2 3 4
E (um/ms2/s)
D. giganteus has a higher Instantaneous WUE.
Plants receiving wastewater appear to have a
higher WUE in comparison to clean water plants.

13. Stem & Branch Biomass
Stem & branches weight (kg) Plants receiving
B. vulgaris
waste water (-w)
had the biggest
1600.0 B. x
culm and branch
1400.0
1200.0
weight.
Giant
1000.0 Bambusa vulgaris
800.0 (middle) did not
600.0 show sensitivity
400.0 to wastewater.
200.0
0.0
GC GW VC VW XC XW

14. Leaf Biomass
Leaves (gm)
Total leaf weight
showed a clear
700.0 B.x difference between
B. vulgaris
600.0 plants receiving
500.0 wastewater and
400.0
Giant
clean water.
300.0
200.0
100.0
0.0
GC GW VC VW XC XW

15. Biomass
Number of Branches
300
XW and VW had the
B.x highest number of
250 new branches.
B.v.
200
GW had a decrease
in number of
Numbe
150 branches in the same
period.
100
giant
50
0
0 1 2 3 4
Months

16. Average Total Leaf Area Per Plant
30000
25000
20000
Square cm
15000
10000
5000
0
0 0.5 1 1.5 Months 2 2.5 3 3.5
B. vulgaris and B.x had more than double the leaf
area of the other treatments.
These treatments therefore have assimilation and
evaporation rates that are three times of the other
three.

17. Chlorophyll Values (SPAD)
45
40
35
30
SPAD
25
20
15
10
5
0
0 1 2 Months 3 4 5
Wastewater plants (orange) had higher chlorophyll
values

18. Preliminary Conclusions
Confirm hypothesis 1 that main responses to
wastewater is increase in leaf area and
chlorophyll.
Although giant bamboo appears to have a higher
WUE it is also the slowest growing.
Water use efficiency was relatively similar
although wastewater WUE appeared to be
higher (significance?).

19. Further Studies
Different sources of wastewater
particularly from industrial sites to be
investigated.
A wider range of concentration of
wastewater to be tested.
Analysis of nutrient uptake to be carried
out.