Present Status of Water Contamination in the Jeju Underground
Water by Nitrate-Nitrogen and its Solutions
Student Researchers: Kim Joo-Hun, Lee Hyo-Jun
Advisor: Park Young-Seoung
Ⅰ. Background of the Research
It started as an ordinary part of my everyday life. It was one of those family trips
where we went up to Suwolbong. It had been quite some time since we had such an
outing and the last time I had gone there was when I was in elementary school. After
coming down from the mountain, we went to Yonguncheon that is located at the foot
of the mountain. However, to my surprise, the water spring, which I had drunk with
such pleasure when I was young, was no longer the one I had remembered. There was
a blatant sign that clearly stated, "NO DRINKING" in front of it. I asked a resident there
why we couldn't drink from it any more. The reply was that the water had been
contaminated which made it impossible for drinking. Furthermore, the water that was
necessary for agricultural purpose was being obtained from a well from another district.
I was shocked by this knowledge. The underground water that was the main source of
water not possible for use in farming because of contamination? I was able to get more
information from the media that the contamination of the underground water nationwide
was even more serious. It is a fact that out of 5 water springs, 1 cannot be used for
drinking at all because of the severity of the contamination.
According to a research, the underground water of the southwestern area is so
contaminated that it cannot be used for potable purpose compared to other areas in
Jeju. There are many kinds of contaminants but the main culprit is attributed to
nitrate-nitrogen. The nitrate-nitrogen when taken into the circulatory system causes
methemoglobinemia and in extreme cases, it is poisonous enough to cause death.
A Jeju ecology specialist says that the contamination by nitrate-nitrogen in the
southwestern area is because of the over use of fertilizers and the wastewater that
comes from the densely populated stables there. Although the nitrate-nitrogen
contamination is limited to the southeastern area now, there is grave danger that it will
spread all over Jeju following the path of the underground waterway. Jeju being an
island depends solely on the underground water for the supply of drinking water. If the
situation was allowed to continue, Jeju Island with its clean water will disappear forever.
It is this precise reason why we started our investigation into the nitrate-nitrogen
contamination of the underground water and how it could be prevented in the future.
Ⅱ. Theoretical Background
1. Jeju Island
1) Underground Water
(1) The Process of Underground Water Formation
The water that reaches the ground in the form of rainfall first passes through the moist
part of the soil and then goes through the aperture of the bedrock that is filled with
oxygen. This level is called the 'zone of aeration'.
Although it contains a certain
amount of water, because it is not able to saturate the soil. It is also known as an
unsaturated zone. It then meets a saturated zone where all the aeration is filled with
water. The upper part of the saturation zone is called the water table. This is where the
underground water exists.
(2) Usage of the
Underground Water
There has been continued
production of 320,000 tons of
water on an yearly basis since
1998 under the brand name
called Samdasoo. This brand
occupies about 25% of the
national market sales. The
amount of production is
scheduled to be increased to
820,000 tons starting this year and will be exported to foreign countries as well.
Products that use Samdasoo include Jeju Samdasoo Tangerines and Jeju Samdasoo
Green Tea.
2) Present Status of the Usage of Jeju Grounds
Present status of the Usage of Jeju Grounds
Category
Plots
Nationwide 99,646.2 7,955.8 12,152.5
535.9
2,533.0
Jeju Island 1,848.3
Seogwipo
City
Fields
Paddy
Orchards
Jeju City
Total
Fields
Highways
Forest
Miscellan
Lands
eous
2,563.6 64,804.9 9,100.5
364.8
8.0
169.1
50.5
74.5
906.6
274.7
977.9
208.9
3.1
64.3
29.5
42.3
463.4
166.4
870.4
155.9
4.9
104.8
21
32.2
443.2
108.3
When you look at the above graph, we can tell that there are a lot of fields in the
western area. The western area's soil has been rich enough for farming since the old
times. That is why we can surmise the fact that there is an extensive use of fertilizers
and a densely populated area of stables in the western area.
3) Nitrate-Nitrogen Contaminated Locations
Nitrate-Nitrogen Contaminated Locations (1999)
3. Nitrate-Nitrogen
1) Nitrate-Nitrogen (NO3-)
The concentration of nitrates is commonly expressed as N03-. The term "nitrate
nitrogen" is used to refer to the nitrogen present that is combined in the nitrate ion.
This nomenclature is used to differentiate nitrate nitrogen from nitrogen in the form of
ammonia (ammonia nitrogen), from nitrogen in the form of nitrite (nitrite nitrogen), etc.
The concentrations are usually expressed in milligrams per liter of nitrogen.
Many ground waters contain small amounts of nitrate nitrogen. Concentrations range
from 0.1 mg/l to 3 or 4 mg/l in most areas. Amounts as high as 100 mg/l have been
found, however. Nitrates may occur in both shallow and deep well supplies, but they
are most common in water from shallow wells. Nitrate nitrogen can result from the
seepage of water through soil containing nitrate-bearing minerals. It may also occur as
the result of using certain fertilizers in the soil; however, nitrates are one of the
products of decomposition of animal and human wastes. Thus, the presence of nitrates
in a water supply indicates possible pollution of the water.
2) Various Reactions to Nitrate-Nitrogen Oxidation
(1) The Oxidation Process in the Soil
Oxidation caused by microorganisms
(2) The Reduction Process of Nitrogen in the Soil.
The nitrate ion is the final oxidized substance of NO3. The reduction process of
nitrogen is a process where the nitrate ion is reduced to NO2, NO, N2O, N2 respectively.
(3) Circulation of Nitrogen
3) Effects on Organisms
(1) Methemoglobinemia
Methemoglobinemia is a disease that happens when there is difficulty in the supply of
oxygen in the body with the combination of hemoglobin and the nitric acid contained
within the contaminated water. The reason behind such a name is that the whole body
turns blue with the shortage of oxygen in the body. Generally speaking, the
methemoglobin occupies about 1 ~ 2% of the hemoglobin within the body. However, if
this percentage goes over 19%, methemoglobinemia occurs leading up to anoxia. This
disease does not occur in adults but mainly in the case of newborns that are less than
100 days old. The babies who suffer from this disease are called a Blue Baby. There
are three main reasons why a young baby contracts methemoglobinemia due to nitrate
contaminated water. First, the young baby's weight is slight making even the smallest
amount of nitrates in its body quite fatal compared to adults. Second, unlike adults, the
body of a few month old newborn can easily have a hemoglobin oxidation within the
body. Newborn babies lack two enzymes that change methemoglobin into hemoglobin.
Third, unlike adults, the acidity in the stomach of the newborn babies is close to neutral
and can easily lead to bacteria proliferation. Due to bacterial proliferation within the
stomach, methemoglobinemia is likely to occur. Even though the mother is healthy, it
can sometimes be seen that the newborn baby has a bluish tint. This kind of symptoms
happen when the mother drinks water that has nitrates in it. In the case of babies who
are provided with oxygen through the blood system of the mother, they are affected
greatly by even a small amount of nitrates. The Blue Baby Disease is a very rare case in
the methemoglobinemia disease.
(2) Miscellaneous Cases
Specialists have said that it is possible to contract cancer such as that of stomach
cancer in the case where there is continuance of taking nitrates into the body. The
nitrates in the body is said to form strong cancerous substances called nitro amine by
reacting with amine or amide in the body. In the case where the mother takes in this
substance, there is high likelihood of giving birth to a baby with congenital handicap.
4. Method of NO3- Detection
1) Brucine Method
When nitrate reacts with Brucine? Sulfanilic acid solution in sulfuric acid
solution, a yellow product is produced. The Brucine method is calibrating the
quantity of nitrate nitrogen by measuring the product's absorption of light at
410nm with the UV visible spectrophotometer.
2) Ion Chromatography
(1) Ion Chromatography
The ion chromatography can be differentiated into two types of whether it has a
suppressor that gets rid of elements right before the detection process according to its
own functional capabilities. Both are basically liquid chromatographic and are
constituted of eluant, the pump which send this eluant, sample entry, separation
column as well as the detector.
According to the design of the separation column, the eluants are separated into
water or the dissociation and the ion that is to be analyzed goes straight through. That
is why it is possible to detect even a small amount of ions.
Even with the method that does not use the suppressor, it is possible to carry out a
highest level of analysis of the various ions with the conductivity detector by using thin
solutions such as the organic acid or the amine that does not have a high
self-conductivity as the eluant. Furthermore, if you choose the appropriate detector for
the targeted ion, it is possible to use a relatively exchangeable large amount of ion
exchange resin in the column.
In the method that does not use the suppressor, when the conductivity detector is
used, the constitution becomes higher so the flow is scattered and is also affected by
temperature. The experiment should be carried out in a stable location with a fixed
temperature.
(2) Scope of Application
In the separation of ions, the ion-eliminated chromatography is used for a pair of
ions are created to apply them to distributed or adhesive chromatography. This various
method of chromatography has made the analysis of negative and positive ion quite
simple and its method has been widely spread to be used in atmospheric and water
analysis.
(3) Manufacture of Crude Liquids
In analyzing small amounts of elements, a reliable manufacturing of standard crude
liquid is required. It has been recommend that an amount of 1,000ppm should be
thinned and prepared beforehand before each usage.
5. Method of Discovering the Origin of NO3-N
1) Detection of NH4+ : Indophenol Method
When sodium phenol reacts with ammonia and hypochlorous sodium in the basic
solution with sodium nitroprusside as a catalyst, it turns into blue. The Indophenol
Method is measuring the product's absorption of light at 630nm with UV-Visible
Spectrophotometer.
(Reaction)
Indophenol, quinoid group, blue
2) The Analysis of Isotopes
(1) Isotopes according to the Origin of Nitrate Nitrogen
The nitrate nitrogen is a chemical compound, which is a very stable form of final
oxide created by nitrate nitrogen. Nitrate ions can be mainly divided into two kinds of
origins that are chemical fertilizers and manure. The nitrate ions have very different
physical characteristics depending on what the main provider was. Its most
representative difference is the concentration of nitrogen isotopes.
First, in the case of chemical fertilizers, the N2 in the atmosphere is used and
combined chemically which makes the concentration of isotopes in the fertilizer similar
to that of the nitrates in the atmosphere.
On the other hand, in the case of animal manure, the amount of N15 is quite extensive
compared to the chemical fertilizers. This can be attributed to the biochemical reaction
that happens within the animal manure. The NO3- in the animal manure is restored to
NH4+ because of the reduction reaction. At this time, the
14
N is lighter in atomic weight
than N15 that makes the reaction velocity much faster. Therefore, the
14
NO3- is used up
at a faster rate. This means that the N15 concentration of animal manure is that much
higher as a result.
Furthermore, the animal manure is a by-product of the life cycle and is a separated
product of amino acid. Therefore, it contains quite a lot of ammoniac elements that had
been separated from the amino acid. As such is the case, the contaminated
underground water by animal manure has a higher percentage of
NH4+ concentration
than the ones that have not been contaminated.
(2) The Unit of Isotope Analysis : δ
The amount of isotope, which exists in the natural world, is quite minimal. Therefore,
it is difficult to obtain a precise measurement. With this reason, the unit expressed as
δ is defined to measure the actual amount of isotopes. The δ is measured by
comparing it to the standard state of the isotope amount possessed by the sample.
In this case, rsam = Ratio of the isotope of the sample
rref = Ratio of the isotope at a standard state
This figure is usually expressed as one millionth out of one. (δ ‰)
(3) The Value of Isotopes in the Manure and Chemical Fertilizers
In the case of atmospheric nitrogen, there is about 0.3663 ppm of
15
amount as the standard, in the case of the atmosphere, it becomes δ
N.
Making this
15
N = 0. The
chemical fertilizers is used by industrializing and combining the nitrogen in the
atmosphere which makes it have a value close to 0. However, with the difference in the
combination process, there is a slight change and makes it have a value which ranges
about -3 ~ +3.
In the case of animal manure, the amount of
the value of the δ
15
N is comparatively larger which makes
15
N quite extensive to as much as more than 10. Furthermore, the
concentration of nitrate ions which had been adhered or melted into the soil reaches up
to about 3~8. Therefore, in these three cases, the concentration ratios of
15
N are all
different and by measuring the isotopes, it is possible to find out where the origin of
the nitrate nitrogen is.
(4) The Principles of the Mass Spectrometer
The mass spectrometer is divided into the ion source that ionizes the gas molecules,
the mass analyzer which divides according to the magnetic field, and the ion collector.
The ion source is the part where it forms the ion and speeds it up so that it can be
collected in the form of beams. It is created as a result of a collision between the
sample gas molecules and the thermo electron discharged by the filament. At this time,
the thermo electron ionizes the gas molecules in the chamber that is the reason why
the ion source must maintain a high degree vacuum state. The ion, (with mass of 'm')
that has escaped the chamber due to the electrodes gains fixed amount of energy.
These electrodes are accelerated due to the voltage ‘V’ into velocity and come to
possess kinetic energy.
Therefore, the ions that have different amount of mass will come to have different
velocities.
The ion beam that would have come to possess a regular kinetic energy mentioned
above passes through a magnetic field 'B'. When it passes through this, it comes to
draw a circle that is the radius 'r' due to the balance between the centrifugal force and
electromagnetic force.
According to the above equation, the ion beams would be separated into the value of
m/e.
6. The Principles of Adhesion of Positive Mineral Ions
1) Zeolite
Zeolite generally refers to natural and compound minerals that have various physical
and chemical characteristics that are industrially useful because of its unique qualities
that exist within their formation. Nowadays, the term Zeolite is also commonly used to
refer to compound substances in labs and factories besides the naturally formed
minerals in the lithosphere. Depending on the neighboring environment, it has a special
characteristic in that it forms a huge space that allows molecules move back and forth
freely within its formation. The term Zeolite is used as a collective name for compound
and natural miners, which has special characteristics in, its constitution as mentioned
above.
As to its formation, all the oxygen of (Si, Al)O4 tetrahedron which is one of the basic
mineral unit of silicates is shared by another tetrahedron and takes on the form of a
mineral called tektosilicates which is connected three dimensionally. Zeolite forms a
cross pattern of specific gravity ranging from 2.0-2.3.
Scholars expanding its usage application greatly have actively carried out more
researches recently about Zeolite. It has come to a situation where a variety of
structure and characteristics of Zeolite is necessary.
(1) Special Characteristics of Zeolite
The special formation of Zeolite induces various physical and chemical reactions.
① Special Characteristics of the Positive Ion Exchange:
The special characteristics of cation exchange of Zeolite which is well known as CEC
(Cation Exchange Capacity) refers to a characteristic which easily induces ionic
exchange within the common space just with the simple process of washing it down
with other positive ion solutions. Generally speaking, the exchange capability of the
Zeolite gets to have a very high value of 200 ~ 400 meg per 100g. Other than having
this high capability of positive ion exchange out of all minerals, Zeolite also has the
capability of displaying a selective function of choosing what to exchange depending
on what type of mineral it is. Out of all the special characteristic of ion exchange on the
part of Zeolite, the main application areas include usage in soil and water amelioration,
processing various industrial and city wastewater and processing radioactive material
wastes.
② Special Characteristics of Absorption and Molecular Sieving :
Zeolite in general possess quite an extensive amount of water in the common area in
its structure (10-15 wt%) but, it becomes dehydrated easily if heated at 200~300℃ for
several hours. This dehydrated Zeolite absorbs appropriate size and forms of organic
and inorganic molecules whereby it comes to possess a highly developed
characteristic of molecular sieving which separates different molecules that have been
mixed together.
③ Catalyst Characteristics
④ Dehydration and Re-absorption Characteristics
⑤ Characteristics related to other Matters
(2) Zeolite Compound Industry
There has been continuous research to combine Zeolite that has new structure and
special characteristics until now. There are more than 200 known types of Zeolite that
have been compounded.
Ⅲ. The Research Process
We first carried out an experiment to detect the amount of nitrate nitrogen contained
within the underground water through the Absorptiometric Analysis Metho d. Then
through the NH4+ detection experiment and the isotope analysis experiment, we
investigated into what the main reason for the nitrate nitrogen contamination was
between the manure and chemical fertilizers. Finally, we conducted an experiment to
purify the nitrate nitrogen by using the ion exchange principles using the Zeolite.
1. Sample Collection
1) Water Sample Collection
A. Water Sample Collection
(1) Collection of two 2L plastic bottles worth of water from the Younguncheon of
Suwolbong
No Drinking Sign
There were two springs in Yonguncheon
(2) Collection of two 2L plastic bottles worth of water from the General Water of
Hangpaduri.
(3) Collection of two 2L plastic bottles worth of water from the Won Water of Geokkuri
Oreum (parasitic volcanoes).
General Water
Won Water
2. The Detection of NO3-N; Nitrate Nitrogen
1) The Absorptiometric Analysis using the Brucine Method
A. Reagent
(1) Salicylic Sodium Solution
1g of salicylic sodium solution is dissolved in
sodium hydroxide solution (0.01N) and made
into about 100㎖.
(2) Sodium Chloride Solution
About 0.2g of sodium chloride solution is
dissolved in water into about 100㎖.
(3) Sulfamic Ammonium
About 0.1g of sulfamic ammonium is
dissolved in water into about 100㎖.
(4) Sodium Hydroxide (2→5)
About 40g of sodium hydroxide is dissolved in
water into about 100㎖.
(5) Nitrate Nitrogen Standard Undiluted Solution
About 0.722g of potassium nitrate which had
been cooled in the desiccator after being
dehydrated for 4 hours in the temperature between
105~110℃ is prepared beforehand and this is
dissolved in water into about 1ℓ . Two drops of chloroform is added to the solution and
stored in a brown bottle (This 1㎖ of solution contains 0.1㎎ of nitrate nitrogen).
(6) Nitrate Nitrogen Standard Solution
The nitrate nitrogen standard solution is diluted hundredfold and is made whenever
necessary. (This 1㎖ solution contains 0.001㎎ of nitrate nitrogen).
B. Testing
(1) Analysis
(A) An appropriate amount of the sample
water (which contains about 0.001～0.2㎎ of
nitrate nitrogen) is poured into a 100㎖
beaker. 1㎖ of salicylic sodium solution, 1㎖
of sodium hydroxide and 1㎖ of sulfamic
ammonium are added to the solution and is
vaporized and hardened in its liquid state.
(B) This is cooled and 2㎖ of sulphuric acid is
added on and stirred occasionally and left alone for about 10 minutes. (In the case
where the amount of residue after vaporization is a lot, it is used after heating it in its
liquid state for about 10 minutes and cooled) After that, 10㎖ of water is mixed in and
transferred to a Nessler casket.
(C) This is cooled again and 10㎖ of sodium hydroxide (2→5) is mixed in and more
water is added to make it into about 25㎖.
(D) Some of this solution is poured into an absorption cell(10㎜), and by using the
photoelectric spectrophotometer or the photoelectric photometer, the blank test
solution which had been tested in the same way as the sample water is treated as the
antithesis solution to measure the absorbency around the wavelength area of 410㎚.
The amount of nitrate nitrogen in the testing solution is obtained from the measurement
level according to (2) and the concentration of nitrate nitrogen in the sample water is
gauged.
Sulphuric Acid Reaction
Bathing the Samples
(2) The Drawing Up of the Measurement Level
About 0~20㎖ of nitrate nitrogen standard solution is poured into a beaker step by step
and is experimented according to the same procedure as stated in (1) so that the
relationship between the absorption of light and the amount of nitrate nitrogen can be
obtained.
Change of the Color of the Sample
2. The Origin of NO3-N; Nitrate Nitrogen
1) The Analysis of Isotope
The Analysis of Isotope was carried out in the following 5 steps.
A. Sampling: Ground Water
B. Distillation: Kjeldanl Method
C. Concentration: Infra Red Lamp
D. Gas Generation N2: Rittenberg Method
E.
15
N Analysis: Stable Isotope Ratio Mass
Spectrometer
For the analysis of N isotope composition
of nitrate, N2 gas was prepared according
to the method of Hauck (1982). The NH4+
in the water sample was removed through
steam distillation with the addition of MgO
to maintain the pH of solution above 10.
The remaining solution was then treated
with Devarda's alloy, and redistilled. The
liberated NH3 formed from NO3- was
trapped in H2SO4. After acidifying the
solution containing NH4+ with 0.01N H2SO4
to pH 3, the solution was concentrated under an infrared lamp. The NH4+ in the
concentrated solution was converted into N2 gas through oxidation using alkaline LiOBr.
The gas was transferred into a stable isotope ratio mass spectrometer for isotopic
composition determination. A N2 gas with δ
15
N value of 0.22% (AIR) was used as a
working standard.
2) Detection of NH4-N; Ammonium Nitrogen
A. Reagent
(1) Phenol Sodium Nitroprusside 5g of
phenol and 25mg of sodium nitroprusside is
dissolved in water into 500㎖.
It is stored in
a cold and dark place and should be used
within the next month.
(2) Hypochlorous Sodium
Hypochlorous sodium(100/c)㎖ (c is the
valid chlorine concentration %) and 15g of sodium hydroxide is dissolved in water to
make it into 1ℓ
and is made whenever necessary.
(3) Ammonium Nitrogen Solution
0.3819g of Ammonium nitrogen solution is dissolved in water to make it into 1ℓ (This
1㎖ solution contains 0.1㎎ of ammonia nitrates).
(4) Ammonium Nitrogen Standard Solution
The ammonia nitrogen standard solution is diluted hundredfold and is made whenever
necessary. (This 1㎖ solution contains 0.001㎎ of ammonia nitrates).
B. Testing
(1) Analysis
(A) 10㎖ of sample water(10㎖ worth of
solution where water was put into the sample
water so that it contains less than 0.01㎎ of
ammonia nitrates or the same amount) is put
into a test tube with a stopper. 5㎖ of phenol
sodium nitroprusside is added into the solution.
The stopper is firmly put in and then the test
tube is shaken quietly for the solution to be
mixed.
(B) Next, 5㎖ of hypochlorous sodium is added and the stopper is put back on. It is
shaken again and stored at a temperature between 25~30℃ for about 60 minutes.
(C) Some of this solution is poured into an absorption cell(10㎜), and by using the
photoelectric spectrophotometer or the photoelectric photometer, the blank test
solution which had been tested in the same way as the sample water is treated as the
antithesis solution to measure the absorbency around the wavelength area of 640㎚.
The amount of nitrate nitrogen in the testing solution is obtained from the measurement
level according to (2) and the concentration of nitrate nitrogen in the sample water is
gauged.
Phenol nitroprusside Sodium Solution & Hypochlorous Sodium Solution
(2) Drawing up of the Measurement Level
About 0~10㎖ of ammonia nitrogen standard solution is put into a test tube in a step
by step process, and water is added to make it into 10㎖. The following procedure is
tested out just as in (1) so that the relationship between the amount of ammonia
nitrates and the absorption of light can be gauged.
3. The Elimination of Nitrate Nitrogen
1) The Absorption of Nitrate Nitrogen by Zeolite
A. Preparation
(1) Zeolite
Zeolite is capable of absorbing
moisture and so if it is placed in
the atmosphere, it most definitely
absorbs the moisture. To
eliminate this moisture, it is
heated beforehand at a
temperature between 200~300℃.
(2) Nitrate Nitrogen Standard Solution
It is dehydrated for 4 hours beforehand at a
temperature between 105～110℃. 0.722g of nitrate
potassium which had been cooled in the desiccator is
dissolved in water to make it into 1ℓ . Two drops of
chloroform is added on and stored in a brown bottle
(This 1㎖ solution contains 0.1㎎ of nitrate nitrogen).
(3) The nitrate nitrogen standard solution is diluted hundredfold and is made whenever
necessary. (This 1㎖ solution contains 0.001㎎ of ammonia nitrates).
B. Soil Sample
(1) To reconstruct the formation of Jeju's
underground, a plastic container is cut up into a
certain appropriate size.
(2) The lower part of the plastic container is
blocked up with gauze and laid down with pebbles.
(3) Cover the pebbles with about 20cm of earth.
(4) Measure about 40g of Zeolite and laid down on the upper part of the earth.
(5) Pour down about 500ml of water over the Zeolite.
(6) Measure the time it takes for the 500ml of water to be drained.
C. Absorption of Negative Ions by Zeolite
(1) About 100ppm of
nitrate nitrogen standard
solution is diluted and is
made to become 5ppm,
10ppm, 20ppm, and
30ppm worth of nitrogen
standard solution.
(2) Measure out 40g of
Zeolite.
(3) The measured Zeolite
is soaked in each
respective nitrogen standard solution as much as the time that was measured in A.
(4) After absorption, use the IC to measure the changes in the amount of NO 3-N by
Zeolite.
Standard Solution of Nitrate-Nitrogen & Zeolite
Ⅳ. Research Results
1. Detection of NO3-N; Nitrate Nitrogen
1) The Absorptiometric Analysis using the Brucine Method
A. The Detection of NO3- using the Brucine Method
Sample #1 Won Water
Sample #2 Yonguncheon
Sample #3 General Water
NO3- Detection (From the Left Sample #1 Won Water,
Sample #2 Yonguncheon, Sample #3 General Water)
The result of the experiment indicated the fact that the NO3- reacted with the salicylic
sodium and took on an orange hue (wavelength 410nm). Through the difference in
color of the samples, we were able to surmise that the concentration of NO 3- was
different. The Won Water showed the lightest color and Yonguncheon showed the
darkest color. Furthermore, the darker the color was, the viscosity of the solution
increased.
B. The Results of the Absorptiometric Analysis of NO3-
Processed Standard Spectra (NO3-)
Standard Name
Concentration (ppm)
Abs (410nm)
Error %
1
Measuring Level 1
0.000000
6.55341E-3
100
2
Measuring Level 2
1.000000
0.73291
0.26
3
Measuring Level 3
2.000000
1.52860
-3.80
4
Measuring Level 4
4.000000
2.90920
1.03
In order to find out the relationship between the color of the sample and the
concentration of the nitrate nitrogen, the measurement level was drawn out by using
the NO3- standard solution whose concentration was already known. Because the
sample took on an orange hue, the absorption of light was compared using the
concentration density at 410nm. The absorption rate became higher for each higher
concentration level of the nitrate nitrogen.
Analysis of Absorption of Light (410nm)
Sample No. Sample Location Dilute Factor Concentration (ppm)
Abs
A.C
1
Won Water
1.000000
0.85277
0.62662 0.85277
2
Yonguncheon
10.00000
3.46490
2.54600 34.6649
3
General Water
4.000000
2.16140
1.59020 8.64560
The above table is the analysis result of the absorption of light. The Absorptiometric
analysis can only measure up to a maximum of 4ppm. Therefore, Yonguncheon was
measured by diluting it tenfold, and General Water was measure by diluting it fourfold.
C. General Analysis
Through the nitrate nitrogen standard solution experiment, we were able to learn that
the absorption of light became higher as much as the concentration level.
The absorption of light was the highest for the tenfold diluted solution of
Yonguncheon, then the fourfold diluted solution of the General Water came next and
finally the Won Water. As such, we were able to predict that the order will be the same
if analyzed in the original concentration amount. The concentration of nitrate nitrogen
became lower. The highest rate of the absorption of light was for Yonguncheon, and
then it became lower for General Water and then finally Won Water.
Through the drawing up of the measurement level, we were able to anticipate that the
nitrate nitrogen concentration would be the lowest for Won Water and the highest for
Yonguncheon.
2) Ion Chromatography
(1) Measurement Level
X axis: Concentration of
Sample
Y axis: Conductivity
We are able to tell that the
concentration of the sample
and conductivity is
proportionate. In other words,
IC's conductivity value could
Measurement Level
be changed to the
concentration ratio.
(2) Won Water
This is the result of an
analysis of won water using
the ion chromatography
method. The second peak
indicates the nitrate
nitrogen. In the Won Water,
it took 9.62 minutes to detect
the NO3- ion and the
Sample #1 Won Water
concentration density at its
peak was 0.85171ppm.
(3) Yonguncheon
This is an ion
chromatography carried out
for the fivefold-diluted water
from Yonguncheon. It took
9.48 seconds for NO3- ions
to be detected. The
concentration of NO3- ions
was 7.42733ppm and the
Sample #2 Yonguncheon (Five times diluted)
actual concentration was
found to be 37.36366ppm
(3) General Water
This is an ion
chromatography carried out
for the sample obtained by
diluting the General Water
twofold. The time it took to
detect the nitrate nitrogen
was 9.52 minutes and the
concentration was
4.35876ppm. Therefore, the
Sample #3 General Water (Two times diluted)
actual concentration density
was detected to be
8.71752ppm.
2. The Origin of NO3-N; Nitrate Nitrogen
1) The Analysis of Isotope
Name
δ
15
N (‰, per million)
Yonguncheon
4.4 (Average 4.3, 4.6, 4.4)
General Water
6.2 (Average 6.0, 6.4, 6.1)
Sample from Yonguncheon, which contains the largest amount of
nitrate-nitrogen(52.83 mg/L), had a ratio of nitrogen isotope of about 4‰, which
shows that origin of nitrate-nitrogen is chemical fertilizer(-5 ~ +5‰), rather than
organic nitrogen compound.(manure etc, above +10‰)
2) The Detection of NH4-N ; Ammonium Nitrogen
A. The Detection of Ammonia Nitrogen
The Detection of Ammonia Nitrogen using the Indo-Phenol Method
When you look at the experiment results, we can see that the concentration density of
ammonia nitrogen is the highest in the order of Won Water, Yonguncheon and finally
the General Water. In the case of Won Water, the amount of nitrate nitrogen was
minimal but found to be extensive in the amount of ammonia nitrogen.
B. Measuring the Absorption of Light
Processed Standard Spectra (NH4+)
Standard Name
Concentration (ppm) Abs (640nm)
%Error
1
Measurement Level 1
0.100000
1.3547E-3
-100.00
2
Measurement Level 2
0.100000
2.0764E-2
-1.08
3
Measurement Level 3
0.200000
0.12025
-0.03
4
Measurement Level 4
0.500000
0.30039
0.05
Analysis of Absorption of Light (640nm)
Sample No.
Sample Location
Dilute Factor Concentration (ppm)
Abs (640nm)
1
Won Water
1.000000
4.0548E-2
1.5771E-2
2
Yonguncheon
1.000000
2.6238E-2
2.4373E-2
3
General Water
1.000000
1.3364E-2
8.0238E-3
When we look at the analyzed result of the rate of absorption of light for ammonia
nitrogen, we are able to see that the amount is quite minimal. All ammonia drinking
water has a level of lower than 0.5ppm, which is the standard level. However, this result
is shown because most of the ammonia nitrogen has been oxidized into nitrate nitrogen.
In other words, the concentration density of nitrate nitrogen has increased due to the
ammonia nitrogen oxidization process.
C. General Analysis
As with nitrate nitrogen, when you look at the drawn up result of the measurement
level of ammonia nitrogen, the absorption of light at 640nm is almost proportionate to
the concentration density of ammonia nitrogen. In the case of Won Water, it is only a
minimal amount of 4.0548×10E-2ppm, but it had the most amount out of the three
samples. The most amount of ammonia nitrogen was detected in the order of
Yonguncheon, and then General Water.
3. The Decrease in Nitrate Nitrogen by Zeolite
This is the result of looking into the possibility of
absorption of nitrate nitrogen by using Zeolite. The
5ppm of nitrate nitrogen solution had a decrease of
about 16%, the 10ppm of nitrate nitrogen solution had
a decrease of about 17%, and finally, the 20ppm and
30ppm of nitrate nitrogen solution had about a 9%
decrease.
The D ecrease in N itrate N itro g en
Before
After
Result of the Zeolite Experiment
30
27.54
30
NO3-N (Nitrate-Nitrogen)
25
Sample
Before
After
20
18.32
20
Unit
ppm
ppm
Sample 1
5.00
4.21
ppm
15
10
8.35
10
Sample 2
10.00
8.35
5
Sample 3
20.00
18.32
Sample 4
30.00
27.54
0
5 4.21
S am ple 1
S am ple 2
S am ple 3
S am p les
S am ple 4
Ⅴ. Conclusions and Observations
Jeju Island is a representative pollution free with a clean and green image within
Korea. At the same time, it is an island. Being an island, the issue of underground
water is directly related to the very survival of the lives of the Jeju residents. The
underground water is an essential resource. If this source of life were to be polluted, it
would change the very outcome of the future Jeju industries and livelihood of the Jeju
people. Through this research, we had hoped to find out preventive measures against
the severity of pollution, source of pollutants and pollution of underground water. By
conducting this research, our objective was to discover means of sustainable
development of the underground water that is a very important resource for Jeju.
We were able to conclude the following from our experiments.
1) The concentration density of the nitrate nitrogen was the highest for Yonguncheon,
followed by General Water and Won Water. Yonguncheon was the one where it had
over 10ppm that is the drinking level point. Furthermore, in order to find out the origin
of the nitrate nitrogen, the concentration density of the ammonium ion was measured.
The highest amount was found in Won Water followed by Yonguncheon and finally
General Water. This signifies that it is a part of the pollution process where the Won
Water is being polluted by ammonia nitrogen. Ammonium Ion becomes nitrate ion with
the oxidation process with more time passing. Through this process, it was found out
that the water that had been polluted the most is Yonguncheon but Won Water which
had the most amount of ammonium ion detected is also likely to have a serious level of
pollution. Furthermore, in the case of Yonguncheon, the level of concentration density
of the nitrate nitrogen was between 34~52ppm, and the General Water was between
6~10ppm. Also the amount of ammonium ion was 0.02ppm in Yonguncheon and
0.04ppm in General Water that is very low. In addition, the result of isotope analysis
showed that each water only had 4.4 and 6.2 of δ
15
N which is below 10.
We could conclude that the origin of nitrate nitrogen was from the chemical fertilizer
rather than the manure.
2) Through the result of the isotope analysis and the concentration density
measurement, we learned that Jeju's underground water was affected more by the
chemical fertilizers rather than the animal manure. Therefore, appropriate administrative
as well as scientific measures preventing animal manure from flowing into the
underground water should be devised as soon as possible.
(1) Scientific Measures
Nitrogen is essential element for plants' growth. As demand for agricultural product
has increased, the use of fertilizer is inevitable. The reason, that the fertilizers cause
problem is because, it dissolves into the underground water and contaminates it.
Recently, to solve this problem a new kind of soil was developed; the soil contains
nitrogen fertilizer inside the particle so the fertilizer does not dissolve into the water, but
plants can still absorb it. This nitrogen containing soil does not let nitrate nitrogen flow
into the underground water. Also by spreading the soil over the ground, it can be used
for 2~3 years. This new technology may have lower density of nitrogen than the
fertilizers that exist nowadays, but it is more environmental and creates lesser nitrate
nitrogen. If we could maximize the density of nitrogen by further studies, it would make
a fine solution to problems caused by nitrate-nitrogen.
(2) Administrative Measures
The southwestern area of Jeju is seriously polluted with nitrate-nitrogen because of
the densely populated stables and farms. So, one of the biggest source of
nitrate-nitrogen is chemical fertilizers used in the area. Banning the use of the
fertilizers is practically impossible. Thus new regulations should be made to reduce the
amount of fertilizers that farmers use.
In the case of Gojawal that is Jeju's representative volcanic area, it has a very high
level of water permeability. Out of these Gotjawals, quite a lot of them are privately
owned and apparently there are many enterprises that dump their animal manure
indiscreetly. In the case of Gotjawal, the stratum is shallow and directly connects to the
underground water that gives way to undisturbed pollution of the underground water by
the nitrate nitrogen. To stop these enterprises, security should be heightened and the
severity of the penalty for such actions should be increased.
3) As a result of the Zeolite experiment, we were able to find out that there was not
much positive effect in the absorption of nitrate nitrogen. Zeolite as a mineral has the
SiO44- component in its make and may be very effective in absorbing cation (positive
ion) but was not very effective with absorbing anion.
As it was seen through several experiments, most of the reason behind nitrate
nitrogen pollution could be amply prevented. In other words, if the Jeju people made up
their mind to do so, the problems could be resolved quite easily. However, the
elimination of nitrate nitrogen is not that easy. It only takes a moment to scatter more
chemical fertilizers or the manure on the fields but it will take years or even eternally
impossible to purify or get rid of them. We have to put all our efforts together to
prevent pollution of the underground water and preserve it as much as possible rather
than just ignoring the problem and looking the other way pretending the problem does
not exist.
Ⅵ. Future Suggestions and Perspectives
We were only able to collect the samples from three locations and if only we had
more time, we would have carried out experiments on more locations to test out the
underground water. Furthermore, we mainly obtained qualitative results from the
experiments, but we hope to carry out more accurate or precise experiments in the
future to obtain a more quantitative result.
On a final note, we were only able to use Zeolite as a preventive measure against
pollution. In the future, we hope to use a variety of methods to research into the
elimination of nitrate nitrogen. During the research, we found an interesting fact about
microorganisms that hastens up the denitrification. We are especially interested in
exploring the option of hastening up the denitrification function using microorganisms.
It is our opinion that the elimination of nitrate nitrogen may be more
environment-friendly and better serving the clean and green image of Jeju using this
method.
※ References
*Books
1. Lee Yong-geun, Hwang Kyu-ja, “ [5th Edition] Analysis of Instruments for
Environmental Analysis” , Donghwa Technology
2. Keum Won-myeong, “ WATER How Esesential It is For The Living” , Academy
Books
3. Park Su-in, Sohn Young-kwan, Ahn Jung-ho, Yi Dong-jin, Jang Tae-wu Jeon
Seung-su, Jeong Gong-su, Jo Bong-gon, Hwang Jeong,
“ The
Pulsing Earth” , Sigma Press
4. Seoul University, “ Principles and Applications of Stable Isotope Ratio Mass
Spectrometer” , Seoul University Press
5. Seoul University, “ Guide to using the NICEM Instrument” , Seoul University
National Instrumentation Center for Environment Management
6. The Korean Earth Science Society, “ Introduction to Earth Science” ,
Kyohakyeongusa
7. Jeong Hae-sang, “ Having Fun with Chemistry Experiments 1” , Kyeomjisa
Science Technology Books
*Reference Sites
http://www.insamo.pe.kr
http://www.jeju.go.kr
http://www.samdasoo.go.kr