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International Conference on Science, Technology and Innovation for Sustainable Well-Being
(STISWB), 23-24 July 2009, Mahasarakham University, Thailand
Dissolved Ammonia Adsorption in Water
Using Over Burnt Brick
Shukra Raj Paudel* and Dr Bhagwan Ratna Kansakar**
*Lecturer, Tribhuvan University, Institute of Engineering,
Pulchowk Campus, Pulchowk, Lalitpur, Nepal
shukra2@hotmail.com
**Professor, Tribhuvan University, Institute of Engineering,
Pulchowk Campus, Pulchowk, Lalitpur, Nepal
br_kansakar@yahoo.com
Abstract
The groundwater of Kathmandu Valley contains very high concentration of ammonia nitrogen which
is in excess of WHO guideline value for drinking water. This study mainly focuses on the removal of
ammonia nitrogen in water by adsorption in locally available over burnt brick. The study was carried
out in a 4.2 cm internal diameter column of 120 cm length packed with over burnt brick in up flow
mode.
The study showed that the ammonia nitrogen removal rate increased with increase in contact time
which decreased with time until steady state condition is attained .The contact time varied from 4
hours to 9.5 hours for different particle sizes. The optimal value of adsorption rate constant was found
as 0.1097 for particle size of 0.850-0.600mm at corresponding contact time of 7 hours. The adsorption
data appears to fit the Freundlich’s isotherm. The fixed bed adsorption operation indicated that the
ammonia nitrogen is the function of service time, bed depth and flow. Linear regression model
showing correlation of these parameters has been developed.
Key Words: Kinetics, Contact time, Isotherms, Column study and linear regression.
1. Introduction supplies have been reported in Mc Carty, et.al.
Ammonia is a natural by-product of the 1967 [5].
decomposition of various types of organic Groundwater quality of Kathmandu valley is
matter. The occurrence of free ammonia degraded up to different level due to
indicates the direct inclusion of organic matter, contamination. Most of local areas have been
particularity those arising from the excrement of experienced with excessively high level of
animal and human species. Surface water may nitrogenous compounds. The Groundwater
also get polluted ammonia due to industrial Resource Development Board (GWRDB, 1989,
discharges. Groundwater drawn from strata [3]) has reported the concentration of ammonia
overlay with clay may sometimes suffer in surface and groundwater as presented in
deoxygenating and comparatively large Table 1. The ammonia concentration up to 19
quantities of free ammonia can arise from the and 95 ppm have been reported in surface water
reduction of nitrate. In populated area, and groundwater respectively. The ammonia
incompletely treated sewage or possibly concentration on the surface and groundwater as
industrial effluent may be another source. The reported by Amatya, 2004 is presented in Table
ammonia also sometimes found in groundwater 2. In drinking water, the ammonia should not
as a result of breakdown of portentous organic exceed 1.5 ppm (WHO, 1990). The ammonia
matter and reduction under anaerobic concentration was found to exceed the WHO
conditions. Various sources of nitrogen in water guideline values in both the surface and ground
waters. The ammonia nitrogen concentration up
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International Conference on Science, Technology and Innovation for Sustainable Well-Being
(STISWB), 23-24 July 2009, Mahasarakham University, Thailand
to 125.07 ppm has been reported. The ammonia P2, P3 and P4) were provided on the column to
nitrogen concentration increases as the depth of take the sample from different depths. The
wells increases. column is filled up with over burnt brick of sizes
Table1: Ammonia Nitrogen Concentration in 0.60 to 0.85 mm up to 80 cm height. The
Kathmandu Valley influent ammonia nitrogen concentration was
Surface Ground fixed at 2.5 and 5 ppm. The experiments
WHO were conducted at flow rates of 123.84
Parameter water water
Guideline m3/m2/day (120 ml/min), 36.80
Max Min Max Min
3 2
Ammonia m /m /day (130 ml/min) and 150.77
1.5 19 <0.1 95 0.1 m3/m2/day (145 ml/min). The schematic
–N (ppm)
diagram of experimental setup is shown
Some methods such as adsorption, reverse in Figure1.
osmosis, chemical precipitation, chemical
oxidation, electrolysis, gas stripping and
biological nitrification or denitrification can be
used for removal of ammonia from water (EPA,
1975, Culp R.L. and Culp G.L. 1971, Kansakar
B.R. 1986, Mc Carty P.L. et.al.1967, Miller
D.G. and Short C.S.1972 and Short C.S., 1975).
Although the many of them proved to be
technically feasible but others factors such as
cost, operational requirements and aesthetic
considerations have not been found favorable in
some cases. For low concentration of ammonia
in water, adsorption of ammonia by using over
burnt brick in local level may be very practical
and economical. The main objective of this
study is to minimize the ammonia concentration
in surface water and groundwater and the Figure 1: Schematic Diagram of Experimental Set Up
performance study of locally available
adsorption media like over burnt brick. The flow was regulated by using Watson
inducer (MHRE MK 4 flow inducer) and
Table2: Ammonia Nitrogen Concentration of Electrolab Peristaltic Pump (PP 50 VX). The pH
Deep Wells in Kathmandu Valley was measured by digital pH meter (DHA-3000-
1706-02) and the temperature was measured by
Location Ammonia-N (ppm) simple thermometer graduated in oC. The
Lokanthali WTP 51-105 ammonium nitrogen concentration was
Kuleshor 60-95 measured by using Ultra violet
IOE Pulchowk Campus 40-117 spectrophotometer as per the Standard Methods,
Balaju 21-38 1980.
Bhaisepati 10-43 3. Result and Discussion
The adsorption equilibria are the most important
physiochemical parameters, which help in
2. Methodology defining the type and process of adsorption. The
The ammonia nitrogen adsorption on over burnt ammonia nitrogen adsorption equilibria study
brick was carried out in column using fixed bed using different particles sized over burnt brick
operation. The study was conducted in a small adsorbents were conducted utilizing non flow
column having internal diameter of 4.2 cm and agitated system. The adsorption of ammonia
length of 120 cm with upflow mode. A nitrogen was observed at equilibria in all
perforated plate with cotton was placed at the particles sizes. Therefore contact time was
base of the column that acted as support for the perceived at time taken for 90% adsorption from
media. Arrangements were made to measure the the aqueous solution of adsorbate. It was noticed
loss of head during the operation. Four ports (P1, that for all particles size the rate of adsorption
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International Conference on Science, Technology and Innovation for Sustainable Well-Being
(STISWB), 23-24 July 2009, Mahasarakham University, Thailand
processed quite rapidly and attained equilibrium adsorbents were calculated to illustrate the time
gradually as presented in Figure 2. This appears dependence of the system. Although the removal
due to external surface reaction. Figure 2 shows of ammonia nitrogen was high initially, the rate
the removed NH3-N concentration and effluent gradually decreased to attain the equilibrium
NH3-N concentration as time progressed. The stage.
initial concentration start decreasing as time Table 3: Contact Time and Adsorption Rate Constant
increase, thus by increasing removed NH3-N
concentration. Particle size Contact Adsorption rate
S.No.
(mm) time (hr) constant
1 0.30-0.15 4 0.054
6
Effluent NH3-N 2 0.425-0.30 5.5 0.0615
5
NH3-N (ppm)
3 0.60-0.425 6 0.0653
4 4 0.85-0.60 7 0.1079
Removed NH3-N
3 5 1.18-0.85 8 0.0977
2 6 2.00-1.18 8.5 0.0898
1 7 2.36-2.00 9 0.0846
8 >2.36 9.5 0.0763
0
0 5 10 15 Table 3 shows that as the particle size increases
Time (hr) the adsorption rate constant also increase up to
Figure 2: Ammonia-N Removal particle size of 0.060 mm. However the
adsorption rate constant decreases for the
Figure 3 shows the ratio of C/Co at various particle sizes from 0.850 to 2.36mm.The optimal
contact time, where C is ammonia nitrogen value of adsorption rate constant was found as
concentration and Co is the initial ammonia 0.1097 for particle size of 0.850-0.600 mm at
nitrogen concentration. The contact time and corresponding contact time is 7 hours.
adsorption rate constant for various particle 3.1 Adsorption Isotherms
sizes at initial ammonia concentration of 5 mg/l The adsorption curves for various sizes-
is presented in Table 3. The contact time of adsorbents were applied to Langmuir’s and
smaller particle size was less as compared to Freundlich’s equations. The Freundlich’s curves
larger particles sizes. The contact time fit better than Langmuir curve and also
increased as the particle sizes increased. The linearised. It can be observed that all the
contact time is calculated as 4 hours for particle isotherms of media seem favorable for the
size of 0.30 - 0.15 mm which increased to 9.5 adsorption data. Typical examples of isotherm
hours for particle size greater than 2.36 mm. The test for media size of 2.36-2.0 mm are presented
effluent ammonia nitrogen concentration in Figures 6 and 7, Similar patterns were noticed
decreases as the contact time increases. for others particle sizes. In graphs, X and m are
the weight of substance adsorbed (contaminant)
1.2
by adsorbent and weight of adsorbent (media)
1.0 respectively.
0.8 0.01
C/Co
0.291
0.6 X/m = 0.0002Ce
2
R = 0.8157
0.001
0.4
X/m
0.2 0.0001
0.0
0 5 10 15 0.00001
Time (hr) 0 1 10
Figure 3: Contact Time Vs C/Co Equilibrium Conc, Ce (mg/l)
The variation of contact time with respect to
particle size is presented in Figure 5. The Figure 6: Freundlich’s Isotherm Test
contact times for various types and sizes of
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International Conference on Science, Technology and Innovation for Sustainable Well-Being
(STISWB), 23-24 July 2009, Mahasarakham University, Thailand
200 0.12
Ce/(X/m) = 852.46Ce + 3979
Rate Constant, K (m 3/kg hr)
10000 180
Adsorptive Capacity, No
R2 = 0.3995 160 0.10
8000 140 0.08
Ce/(X/m)
120
(kg/m 3)
6000 K
100 0.06
4000 No
80
60 0.04
2000
40 0.02
0 20
0 2 4 6 0 0.00
5.16 5.7 6.28
Equilibrium Conc, Ce (mg/l)
Flow (m/hr)
Figure 7 Langmuir Isotherm Test
Figure 9: Adsorption Capacity and Rate Constant
3.2 Column Study 3.3 Linear Regression Analysis
The column study was carried out for ammonia In order to develop relationship between
nitrogen adsorption capacity in the fixed bed ammonia removals, depth of media, flow rate
column containing over burnt brick. The and service time, linear regression analysis was
ammonia nitrogen concentration at various done using SPSS as a tool. The mathematical
flows and bed depths i.e. P1 (port at 20 cm model developed is given below:
depth), P2 (port at 40 cm depth), P3 (port at 60
cm depth), and P4 (port at 80 cm depth) were ΔN = C H 0.084 Q0.514 T 0.521 (1)
measured and their breakthrough curves are
presented in Figure 8. Where,
It was noticed that as flow decreased and or bed ΔN = Ammonia – N removed (ppm)
depth increased, the trend of effluent H = Depth of media (cm)
concentration is flatter and vice versa. At the Q = Discharge to be supplied (lit/min)
time of attaining exhaustion the slope was more T = Service time (minute)
flat in low flow and less flat in high flow rate. C = Constant coefficient (C = Antilog (-1.267))
Figure 8 shows that the exhaust time at the The above regression model can be used for
various depths of media at flow of 120 ml/min. design purpose i.e. size of treatment plant to
1.0 adsorb ammonia nitrogen by using over burnt
P1
P2 brick. This model considers only the major
0.8 P3 parameters such as depth of media required,
(P) Outlet ammonia nitrogen concentration to be removed,
C/Co
0.6 service time and discharge while other
parameters like temperature, pH remaining
0.4
constant.
4. Conclusion
0.2
0 5 10 15
Following conclusions have been drawn from
the study.
Time (hr)
1. The ammonia nitrogen removal rate
increased with increase in contact time at
Figure 8: Breakthrough Curve for NH3-N Adsorption
the initial phase, which decreases with time
The rate constant (K) and adsorptive capacity until steady state condition is attained.
(No) for over burnt brick of 0.850-0.600mm size 2. The contact time and the rate of adsorption
are presented Figure 9. It can be seen at various (K) increase with increase in particle size.
flow rates that as flow increases, the rate The optimum value of adsorption rate
constant increases while adsorptive capacity constant was found at particle size of 0.850-
decreases. 0.600 mm, and then rate of adsorption
decreased as the particle size increased.
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International Conference on Science, Technology and Innovation for Sustainable Well-Being
(STISWB), 23-24 July 2009, Mahasarakham University, Thailand
3. Freundlich’s isotherms were found best to [5] Mc Carty, P.L., et.al., “Source of
describe the ammonia nitrogen adsorption of Nitrogen and Phosphorous in Water
over burnt brick. Supplies”, Journal of American Water
4. As the discharge increases, adsorption Works Association, Vol. 59, No.3,
capacity of over burnt brick decrease where March 1967, pp.345-366.
as rate constant and critical bed depth [6] Miller D.G. and Short C.S., “Costs of
increase. Water Treatment”, The Trent
5. The linear regression mathematical model Research Programme, Water
developed will be helpful for calculating Resources Board, Vol. 5, 1972.
ammonia removal in fixed bed applications. [7] Short C.S. “Removal of Ammonia
from River Water”, Water Research
5. Acknowledgement Centre, Medranham , Bucks,
I wish to express my deep sense of gratitude and Technical Report TR-3, 1975.
[8]
sincere thanks to Prof. Dr. Bhagwan Ratna Standard Method for the Examination
Kansakar and Associate Professor Mr. Iswar of Water and Wastewater, APHA-
Man Amatya for their excellence guidance, AWWA-WPCF, 15th Edition, 1980.
constant inspiration, regular monitoring and all [9] WHO, Health and Safety Guidelines,
round assistance that enabled me to bring this 1990.
research work in present form.
I extend my profound gratitude to Prof. Dr.
Vinod Tare of Environmental Engineering, IITK
for his valuable suggestions.
I express my sincere thanks and gratitude to Mr.
Mahesh Prasad Bhattarai, Coordinator of
Environmental Engineering Program of Institute
of Engineering, for his valuable suggestion
during literature collection.
My thanks also go to Asso. Prof Padma Sundar
Joshi of IOE for his all round supports. I would
also like to extend my appreciation to Mr.
Nagendra Bahadur Amatya for his valuable
suggestion during data analysis.
Finally, I would like to thanks to Mrs. Prabha
Karmacharya, Miss Goma Yakami, Mr. Keshab
Bhattari and Mr. Sagar Devkota for their kind
cooperation extended during the research work.
6. References
[1] Amatya I.M., Ph.D. “Ammonia Removal
in Water”, Directed study submitted in
partial fulfillment of the requirement for
Ph.D. Study, Institute of Engineering Aug.
2004.
[2] Culp R.L. and Culp G.L. “Advanced
Wastewater Treatment”, Van Nostrand
Remold, New York, 1971.
[3] GWRDB, A Report on Ground water
Management Project in the Kathmandu
Valley, JICA, 1989.
[4] Kansakar B.R., “Nitrification of Water in
Gravel Filters for Drinking Purpose”,
Ph.D. Thesis, Tokyo University, Tokyo,
Japan, 1986.
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