The drain water sample had the highest BOD level of 0.963 mg/L, indicating it was the most polluted water. Distilled water had the lowest BOD level of 0.412 mg/L, showing it was the least polluted. BOD levels increased over time as microorganisms broke down organic matter, using up dissolved oxygen. Drain water likely had a high BOD due to large amounts of waste providing food for microorganisms. This experiment demonstrated how BOD can identify relative pollution levels between different water samples.
Biological Oxygen Demand Lab Analysis and BackgroundJonathan Damora
The purpose of this experiment is to perform a Biochemical Oxygen Demand test on primary clarifier effluent from a wastewater treatment plant to determine a BOD versus time curve. This curve can then be used to determine the Ultimate BOD of the wastewater sample and the rate constant for its decay.
Biochemical Oxygen Demand and its Industrial SignificanceAdnan Murad Bhayo
BOD is the amount of dissolved oxygen needed by aerobic biological organism in a body of water to breakdown organic material present in a given water sample at certain temperature over a specific time period .
Most of Bacteria in the aquatic columns are aerobic. Escherichia coli, Bacillus subtilis, Vibrio cholera.
Atmosphere contains 21% oxygen (210000 mg/dm3)
Higher the temperature of water higher will be the rate of respiration. So, concentration of oxygen decreases.
Many Animal species can grow and reproduce normally when dissolved oxygen level is ~ 5.0 mg/L.
HYPOXIA: When dissolve oxygen content below 3.0 mg/L. Many Species move elsewhere and immobile species may die
ANOXIA: When dissolve oxygen content below 0.5 mg/L. All aerobic species will die
Fertilizer contains Nitrate contributes to high BOD
Phosphate present in Soap and detergent that enhances the growth of algal blooms. As a result depletion of oxygen occur.
In a body of water with large amount of decaying organic material , the dissolved oxygen level may drop by 90 %, this would represent High BOD
In a body of water with small amount of decaying organic material , the dissolved oxygen level may drop by 10 %, this would represent Low BOD
ANALYSIS OF BOD OF WATER
Use glass bottles having 60 mL or greater capacity. Take samples of water.
Turn on the constant temperature chamber to allow the
controlled temperature to stabilize at 20°C ±1°C.
Record the DO level (ppm) of one immediately.
Place water sample in an incubator in complete darkness at 20 C for 5 days. Exclude all light to prevent possibility of photosynthetic production of DO
If don't have an incubator, wrap the water sample bottle in aluminum foil or black electrical tape and store in a dark place at room temperature (20o C or 68 °F).
DILUTION OF SAMPLE
Most relatively unpolluted streams have a BOD5 that ranges from 1 to 8 mg/L
Dilution is necessary when the amount of DO consumed by microorganisms is greater than the amount of DO available in the air-saturated.
If the BOD5 value of a sample is less than 7 mg/L, sample dilution is not needed.
The DO concentration after 5 days must be at least 1 mg/L and at least 2 mg/L lower in concentration than the initial DO
(American Public Health Association and others, 1995).
BOD of the dilution water is less than 0.2 mg/L.
Discard dilution water if there is any sign of biological growth.
pH of the dilution water needs to be maintained in a range suitable for bacterial growth
Bacterial growth is very good between 6.5 to 7.5
Sulfuric acid or sodium hydroxide may need to be added to the dilution water to lower or raise the pH, respectively.
CALCULATION:
The general equation for the determination of a BOD5 value is:
BOD = D1-D2/P
Where
D1 = initial DO of the sample,
D2 = final DO of the sample after 5 days, and
P = decimal volumetric fraction of sample used.
If 100 mL of sample a
Biological Oxygen Demand Lab Analysis and BackgroundJonathan Damora
The purpose of this experiment is to perform a Biochemical Oxygen Demand test on primary clarifier effluent from a wastewater treatment plant to determine a BOD versus time curve. This curve can then be used to determine the Ultimate BOD of the wastewater sample and the rate constant for its decay.
Biochemical Oxygen Demand and its Industrial SignificanceAdnan Murad Bhayo
BOD is the amount of dissolved oxygen needed by aerobic biological organism in a body of water to breakdown organic material present in a given water sample at certain temperature over a specific time period .
Most of Bacteria in the aquatic columns are aerobic. Escherichia coli, Bacillus subtilis, Vibrio cholera.
Atmosphere contains 21% oxygen (210000 mg/dm3)
Higher the temperature of water higher will be the rate of respiration. So, concentration of oxygen decreases.
Many Animal species can grow and reproduce normally when dissolved oxygen level is ~ 5.0 mg/L.
HYPOXIA: When dissolve oxygen content below 3.0 mg/L. Many Species move elsewhere and immobile species may die
ANOXIA: When dissolve oxygen content below 0.5 mg/L. All aerobic species will die
Fertilizer contains Nitrate contributes to high BOD
Phosphate present in Soap and detergent that enhances the growth of algal blooms. As a result depletion of oxygen occur.
In a body of water with large amount of decaying organic material , the dissolved oxygen level may drop by 90 %, this would represent High BOD
In a body of water with small amount of decaying organic material , the dissolved oxygen level may drop by 10 %, this would represent Low BOD
ANALYSIS OF BOD OF WATER
Use glass bottles having 60 mL or greater capacity. Take samples of water.
Turn on the constant temperature chamber to allow the
controlled temperature to stabilize at 20°C ±1°C.
Record the DO level (ppm) of one immediately.
Place water sample in an incubator in complete darkness at 20 C for 5 days. Exclude all light to prevent possibility of photosynthetic production of DO
If don't have an incubator, wrap the water sample bottle in aluminum foil or black electrical tape and store in a dark place at room temperature (20o C or 68 °F).
DILUTION OF SAMPLE
Most relatively unpolluted streams have a BOD5 that ranges from 1 to 8 mg/L
Dilution is necessary when the amount of DO consumed by microorganisms is greater than the amount of DO available in the air-saturated.
If the BOD5 value of a sample is less than 7 mg/L, sample dilution is not needed.
The DO concentration after 5 days must be at least 1 mg/L and at least 2 mg/L lower in concentration than the initial DO
(American Public Health Association and others, 1995).
BOD of the dilution water is less than 0.2 mg/L.
Discard dilution water if there is any sign of biological growth.
pH of the dilution water needs to be maintained in a range suitable for bacterial growth
Bacterial growth is very good between 6.5 to 7.5
Sulfuric acid or sodium hydroxide may need to be added to the dilution water to lower or raise the pH, respectively.
CALCULATION:
The general equation for the determination of a BOD5 value is:
BOD = D1-D2/P
Where
D1 = initial DO of the sample,
D2 = final DO of the sample after 5 days, and
P = decimal volumetric fraction of sample used.
If 100 mL of sample a
Lecture notes of Environmental Engineering-II as per Solapur university syllabus of TE CIVIL.
Prepared by
Prof S S Jahagirdar,
Associate Professor,
N K Orchid college of Engg and Technology,
Solapur
Lecture notes of Environmental Engineering-II as per Solapur university syllabus of TE CIVIL.
Prepared by
Prof S S Jahagirdar,
Associate Professor,
N K Orchid college of Engg and Technology,
Solapur
Details about Biochemical Oxygen Demand(BOD) with solved examples. Extra examples are given for homework. You can contact me for details on pratik1516@gmail.com.
5) What is the dependent variable measured in the BOD test (Explain .pdfRITU1ARORA
5) What is the dependent variable measured in the BOD test? (Explain how you reach your
conclusion) 6) The BOD test is an indirect measure of the concentration of organic
biodegradable materials in a wastewater. Explain in which way is considered an \"indirect\"
Solution
1. BOD is not a specific pollutant. BOD is a measure of the amount of oxygen required by
bacteria and other microorganisms to oxidize any organic matter in the water biochemically.
BOD analysis dose not oxidize all of the organic matter present in the waste. Only the organics
that are biochemically degradable during the standard 5 day time are oxidized. A very low mount
of BOD would indicate either clean water, or that the available microorganisms are uninterested
in consuming the available organic compounds, or that the microorganisms are dead or dying.
Temperature has a pronounced effect on oxygen uptake, because metabolic activity increases
significantly at higher temperature. The time allotted for the test is also important, since the
amount of oxygen used increases with time. Light is also an important variable since most
natural waters contain algae and oxygen that can be replenished in the bottle if light is available.
And the all that is depending on the temperature and and the amount of organic content is
Oxygen so it is the dependent variable .
2.The BOD test is considered as indirect measure of organic biodegradable matter because in this
test we are not going to test and examine the type and concentration of each organic matter by
directly , by measuring the oxygen demand we can easily find the concentration of biodegradable
organic matter.
Wastewater treatment is a process used to remove contaminants from wastewater and convert it into an effluent that can be returned to the water cycle. Once returned to the water cycle, the effluent creates an acceptable impact on the environment or is reused for various purposes (called water reclamation).
A Survey on the Analysis of Dissolved Oxygen Level in Water using Data Mining...IIRindia
Data Mining (DM) is a powerful and a new field having various techniques to analyses the recent real world problems. In DM, environmental mining is one of the essential and interesting research areas. DM enables to collect fundamental insights and knowledge from massive volume of environmental data. The water quality is determining the condition of water in the environment. It represents the concentration and state (dissolved or particulate) of some or all the organic and inorganic material present in the water, together with certain physical characteristics of the water. The Dissolved Oxygen (DO) is one of the important aspects of water quality. The DO is the quantity of gaseous oxygen (O2) incorporated into the water. The DO is essential for keeping the water organisms alive. The amount of DO level in the water can be detected by various methods. The data mining techniques are properly used to find DO Level in the different types of water. A number of DM methods used to analyze the DO level such as Multi-Layer Perceptron, Multivariate Linear Regression, Factor Analysis, and Feed Forward Neural Network. This survey work discusses about such type of methods, particularly used for the analysis of DO level elaborately.
InstructionsAs you have read this week, wastewater treatment.docxnormanibarber20063
Instructions
As you have read this week, wastewater treatment is vital to maintaining human health and producing a sustainable society. Watch the video Water Resource Recovery Facility 3D Virtual Tour. Then, evaluate the primary, secondary, and advanced stages that occur at a wastewater treatment facility. Additionally, discuss at least two policies that might decrease the production of wastewater in the face of increased population growth.
Your initial post should be at least 250 words in length. Support your claims with at least two scholarly sources in addition to your text. Properly cite any references in APA format
Grading Criteria Wastewater Treatment
4 points possible
Content Criteria
Weight
The student describes the primary, secondary, and advanced stages of wastewater treatment.
1
The student discusses at least two policies for the reduction of wastewater production.
1
The student responds to at least two classmates’ initial posts by Day 7.
0.75
Research Criteria
The student utilizes at least two scholarly sources in addition to the text.
1
Style Criteria
The student utilizes APA format, provides a posting of at least 250 words, and answers with correct spelling and grammar.
0.25
Required Resources
Required Text
1. Environmental Science: Earth as a Living Planet
a. Chapter 18: Water Supply, Use, and Management
b. Chapter 19: Water Pollution and Treatment
Multimedia
1. WaterEnvironmentFed. (2012, September 26). Water resource recovery facility 3D virtual tour [Video clip]. Retrieved from http://www.youtube.com/watch?v=A2FmNrEmowE
· Transcript
Recommended Resources
Article
1. U.S. Environmental Protection Agency. (2013). Wastewater technology. Retrieved from http://water.epa.gov/scitech/wastetech/
Website
1. U.S. Environmental Protection Agency. (2013). Water. Retrieved from http://water.epa.gov/
CHAPTER 19
Botkin, D. B., & Keller, E. A. (2014). Environmental science: Earth as a living planet (9th ed.). Hoboken, NJ: John Wiley & Sons, Inc.
19.1 Water Pollution
Water pollution refers to degradation of water quality. In de- fining pollution, we generally look at the intended use of the water, how far the water departs from the norm, its effects on public health, or its ecological impacts. From a public- health or ecological view, a pollutant is any biological, physi- cal, or chemical substance that, in an identifiable excess, is known to be harmful to desirable living organisms. Water pollutants include heavy metals, sediment, certain radioac- tive isotopes, heat, fecal coliform bacteria, phosphorus, ni- trogen, sodium, and other useful (even necessary) elements, as well as certain pathogenic bacteria and viruses. In some instances, a material may be considered a pollutant to a par- ticular segment of the population, although it is not harmful to other segments. For example, excessive sodium as a salt is not generally harmful, but it may be harmful to people who must restrict salt intake for medical reason.
List two factors that influence the BOD degradation rate constant, a.pdfaircommonline
List two factors that influence the BOD degradation rate constant, and how they influence them
(i.e. when factor X increases the rate increases; not just factor X affects the rate).
Solution
The BOD reaction rate constant is dependent on the following:
1. The nature of the waste
2. The ability of the organisms in the system to utilize the waste
3. The temperature
Nature of the waste: Thousands of organic matter exists with different chemical composition in
nature. All organic matter will not have same degradation rate. Simple sugar and starches are
rapidly degraded and will therefore have a very large BOD rate constant. Cellulose degrades
much more slowly and hairs are almost undegradable during BOD test or during biological
treatment of wastewater. Other compounds are intermediate degradable between these extremes.
For complex waste, like sewage, the BOD rate constant depends upon the relative proportions of
the various components. The BOD rate constant is high for the raw sewage (K (base e) = 0.35 -
0.7 per day) and low for the treated sewage (K (base e) = 0.12 - 0.23 per day), owing to the fact
that, during wastewater treatment the easily degradable organic matter will get more completely
removed than the less degradable organics. Hence, in the treated wastewater, relative proportion
of the less biodegradable organic matter will be higher, giving lower BOD rate constant.
Ability of organisms to utilize waste: Every microorganism is limited in its ability to utilize
organic compounds. Many organic matters can only be utilized by particular group of
microorganisms. In natural environment, where the water course is receiving particular organic
compound, the microorganisms which have capability to degrade that organic matter will grow
in predominant. However, the culture used during BOD test may have very small fraction of the
organisms which can degrade that particular organic compounds in the waste. As a result the
BOD value, for limited incubation duration, and the rate constant would be lower in the
laboratory test than in the natural water where the waste is regularly discharged. Therefore, the
BOD test should be conducted with organisms which have been acclimated to the waste so that
the rate constant determined in the laboratory can be compared to that in the river.
Temperature: The biochemical reactions are temperature dependent and the activity of the
microorganism increases with the increase in temperature up to certain value, and drop with
decrease in temperature. Since, the oxygen utilization in BOD test is caused by microbial
metabolism, the rate of utilization is similarly affected by the temperature. The standard
temperature at which BOD is determined is usually 20o C. However, the water temperature may
vary from place to place for the same river.
Determination of p h of waste water sample .....................................Hafiz M Waseem
ecologyDetermination of pH of Waste Water Sample ..................................................... 4
Determination Dissolved Oxygen within Water ................................................... 5
Adaptive Features of Animals in Relation to Food and Environment .................. 7
Study the Plant Population Density ................................................................... 10
Experimental Design and Approaches to Ecological Research ........................ 12
this presentation showsChemical oxygen demand (mg O2 / lit.) which is the amount of oxygen required for reacting with the organic (harmful) matter present in waste water, both soluble or insoluble (suspended) matters, producing CO2 and H2O. In this experiment, organic compounds are oxidized to carbon dioxide and water by a boiling acid dichromate solution
Materials
Waste water sample.
Distilled water.
Potassium dichromate (K2Cr2O7).
Sulfuric acid (H2SO4).
Silver sulfate (Ag2SO4).
Mercuric sulfate (HgSO4).
and procedures
Take a sample of waste water (2.5 ml) in a standard test tube.
Add K2Cr2O7 (1.5 ml) to the above sample.
Add 3.5 ml of a solution containing H2SO4, Ag2SO4 and HgSO4 to the above mixture. This solution is known as "digestion solution" which is prepared by adding Ag2SO4 and HgSO4 to 1 kg of H2SO4.
Repeat the above procedure with a sample of distilled water (2.5 ml) in another test tube.
Heat the two test tubes in the reactor for 2 hrs. at a temperature of 150 ºC and after that leave them to cool.
Use the spectrophotometer to detect the COD (in mg/lit.) value for the waste water sample.
some notes
K2Cr2O7 is used as an oxidizing agent (source of oxygen needed to react with organic matters).
H2SO4 is a digesting agent which helps in decomposing the organic matters to be easily reacted with oxygen.
Ag2SO4 is used to reduce the volatility of the organic matters exist in the waste water sample and keep them in liquid phase. If those matters vaporized, the measured value of COD will be incorrect.
HgSO4 is used to avoid oxidation of 〖𝐶𝑙〗^− if it exists in wastewater as salt. This will lead to high misleading value of COD since 〖𝐶𝑙〗^− is oxidized by K2Cr2O7 into Cl2.
The distilled water sample is used as a blank sample which allows the calibration of the spectrophotometer. The COD value for this sample is zero.
also shows Biological oxygen demand (mg O2 / lit.) is the amount of oxygen required to be used up by bacteria so as to decompose the waste matters in a liter of wastewater. This test may need at least 3 months to be finished: the standard test defines it as BOD5 as it is performed within 5 days only. During those 5 days, about 70 – 80% of degradation is achieved.
In the COD test we completely oxidize the wastes, whether biodegradable (i.e. can be decomposed by bacteria) or non – biodegradable.
In the BOD test we oxidize the biodegradable wastes only.
Determination of the BOD5 of undiluted samples of sewage containing high levels of industrial pollutants may be considerably impaired(damaged) by the presence of inhibitors or toxic substances. Measurements can only be carried out after the sample has been diluted with dilution water that contains a sufficient amount of nutrients and microorganisms in order to reduce the interfering substances to an acceptable level.
Determination of the BOD5 of undiluted samples of sewage containing high levels of industrial pollutants may be considerably impaired(damaged) by the presence of CO
0.0 EXPERIMENT ON DETERMINATION OF DISSOLVED OXYGEN
Bod btl2 new
1. DEPARTMENT OF SCIENCE
FACULTY OF SCIENCE AND MATHEMATICS
UNIVERSITI PENDIDIKAN SULTAN IDRIS
ASSIGNMENT (DATA LOGGER)
SSI3013 : INFORMATION COMMUNICATION
AND TECHNOLOGY
Semester I Session 2012/2013
NAME AND ID NUMBER 1. NUR WAHIDAH BT SAMI’ON D20101037525
2. NOR HASHIMAH BT ZAITONG D20101037458
3.NUR ASHIKIN BT ALIAS D20101037459
LECTURER : MR.AZMI BIN IBRAHIM
GROUP :B
DATE OF SUBMITTED : 03 December 2012
Title : Biochemical Oxygen Demand (B.O.D)
1
2. Objectives :
1. To identify the BOD using data logger.
2. To determine biochemical oxygen demand in the given water sample.
3. To perform a basic experiment to determine the water quality of a given system based on
biochemical oxygen demand (BOD).
4. To determine most polluted water sample.
Hypothesis:
The higher B.O.D value, the more polluted the source of water.
Variables:
1. Manipulated : Sample of water
2. Responding : Dissolved oxygen value
3. Constant : Volume of water sample
Introduction:
Data logger is a device such as lab instrument to record all data generated or the data
passing through a particular point in a networked computer system. It can record a wide variety
of energy and environmental measurements including temperature, relative humidity, light
intensity, oxygen dissolve (DO), water level and soil moisture. Data loggers are used in a broad
range of indoor, outdoor and underwater environments that essentially anywhere data is needed
and the convenience of battery power is preferred.
Figure 1: BOD data logger
2
3. Biochemical oxygen demand or B.O.D is a chemical procedure for determining the
amount of dissolved oxygen needed by aerobic organisms in a water body to break the organic
materials present in the given water sample at certain temperature over a specific period of time.
It is not a precise quantitative test, although it is widely used as an indication of the quality of
water. BOD of water or polluted water is the amount of oxygen required for the biological
decomposition of dissolved organic matter to occur under standard condition at a standardized
time and temperature. Usually, the time is taken as 5 days and the temperature is 20 °C.
The test measures the molecular oxygen utilized during a specified incubation period for
the biochemical degradation of organic material (carbonaceous demand) and the oxygen used to
oxidize material such as sulfides and ferrous ion. It also may measure the amount of oxygen used
to oxidize reduced forms of nitrogen (nitrogenous demand).
The BOD test is widely used to determine the pollution strength of domestic and
industrial wastewaters in terms of the oxygen that they will require if discharged into natural
watercourses in which aerobic conditions exist. The test is one of the most important both in
regulatory work and in studies designed to evaluate the purification capacity of receiving water
bodies.
We take sample of water at pond water, drain water, distilled water, aquarium water and
pipe water. So we use data logger to get the result from the entire water sample. Therefore, BOD
value is determined by the following formula:
BOD value in mg/l = [(D1-D2) – (B1-B2)] /P
Where;
D1= initial DO in a sample
D2= final DO in a sample
B1= initial DO in blank
B2= final DO in blank
P= fraction of the BOD bottle that is represented by the sample
3
4. Apparatus:
Beaker, D.O Probes @ Dissolves oxygen meter (sensor), Computer with Data Logger
Spreadsheet Program.
Materials:
Pond water, drain water, distilled water, aquarium water and pipe water
Procedure:
1) 5 beakers were labeling with A, B, C, D and E.
2) 100 mL of pond water are collected and pour into beaker A.
3) *The D.O probe was placed in the beaker A to read the initial D.O concentration directly.
4) The result was recorded in Data Logger Spreadsheet Program.
5) Steps 1 to 4 were repeated by using different samples of water which are drain water,
distilled water, aquarium water and pipe water which the samples of water is poured into
beaker B, C, D and E respectively.
6) The samples were let until 5 days and D.O probes was placed again in these samples to
read the final D.O concentration.
7) BOD value was determined by the following formula:
B.O.D value = Final D.O – Initial D.O
p
*Note that, before put the sensor into the next sample of water, rinse the sensor with
distilled water.
Results and Data:
4
6. Analysis:
From the graph above, there are five different colour lines of graph means that, it has five
different water samples. The blue line represents drain water. The red line represents aquarium water. The
pink line represents pond water. The green line represents pipe water. The last purple line represents
distilled water. This graph shows the BOD (Biological Oxygen Demand) level of the water sample
against time.
From this graph, it shows the drain water have the highest BOD level which is 0.963mg/l. While,
the lowest BOD level is distilled water which have 0.42 mg/l. This shows that the most polluted water
sample is drain water followed by aquarium water sample, pond water, pipe water and the less polluted
water sample is distilled water. Beside that, from the graph shows the BOD level will increase over the
time. It can be said that the BOD level is directly proportional to the time.
6
7. Discussion:
Biological Oxygen Demand (BOD) is a measure of the amount of oxygen that bacteria will
consume while decomposing organic matter under aerobic conditions. BOD is determined by incubating a
sealed sample of water for five days and measuring the loss of oxygen from the beginning to the end of
the test. Samples often must be diluted prior to incubation or the bacteria will deplete all of the oxygen in
the bottle before the test is complete.
The very important thing to know is the dissolve oxygen (DO) content of the sample to measuring
the BOD of a water sample. The amount of DO in water affects natural biochemical processes in two
ways where by limiting the amount of oxygen available for respiration and by affecting the solubility of
essential nutrient in the water sample. The decomposition of organic matter is the greatest factor in the
depletion of available oxygen in water body. As the organic content in water increase, there is a
corresponding increase in bacterial activity and decrease the dissolved oxygen content.
The microorganisms such as bacteria are responsible for decomposing organic waste. When the
organic matter such as dead plants, leaves, grass clippings, manure, sewage, and food waste also present
in a water supply. This will support the bacteria to begin process of breaking down the waste. This
situation can cause more available dissolve oxygen was consumed by aerobic bacteria, robbing other
aquatic organisms that need oxygen to live.
If there is a large quantity of organic waste in the water supply, there will also be a lot of bacteria
present working to decompose this waste. In this case, the demand for oxygen will be high in the water
sample due to the bacteria will cause the BOD level will be high. As the waste was consumed or
dispersed through the water sample, BOD level will begin to decline.
In this experiment, drain water have been identified have high BOD level may be due to the large
amount of the microorganisms to decompose waste. In drain have a lot of waste from many different
sources such as waste from house and farming area. All this types of microorganism working together to
decompose waste and will cause large number of oxygen demand. On the other hand, the distilled water
shows low BOD level. This case was due to the small amount of microorganisms and causes the oxygen
demand to be low.
In the farming area, there presents the inorganic substances like nitrates and phosphates from the
fertilizer that was used by the farmer. The nitrates and phosphorus in a body of water can contribute to
high BOD levels. These nutrients are essential for the growth of algae and other plants. Aquatic life is
dependent upon these photosynthesizers, which usually occur in low levels in surface water. Excessive
7
8. concentrations of nutrients can over stimulate aquatic plant and algae growth. Bacterial respiration and
organic decomposition can use up dissolved oxygen.
Fertilizers, failing septic systems, waste water treatment plant discharges, and wastes from pets
and farm animals are typical sources of excess nutrients in surface waters. In aquatic ecosystems, because
phosphorous is available in the lowest amount, it is usually the limiting nutrient for plant growth. This
means that excessive amounts of phosphorous in a system can lead to an abundant supply of vegetation
and cause low DO. Increased nitrogen levels adversely affect cold-water fish more than they do warm
water fish.
In addition, metabolic rate and the reproductive activities of aquatic life are controlled by water
temperature. Metabolic activity increases with a rise in temperature, thus increasing a fish demand for
oxygen. Temperature of water also can increase and cause to high BOD level. Therefore, warmer water
usually has high BOD level than colder water. When the water temperature increases, the rate of
photosynthesis by algae and other plant life in the water also increases. When this situation happens, it
can make plant die faster and they will fall to the bottom of the water body so that they can be
decomposed by bacteria. Therefore, increased water temperatures will speed up bacterial decomposition
and result to high BOD levels. A rise in temperature also can provide conditions for the growth of disease
causing organisms.
As the BOD level is high, dissolved oxygen (DO) level will decrease because the oxygen
available in water is being consumed by microorganisms in the water. Since less dissolved oxygen is
available in the water, organisms such as fish, caddisfly larvae and mayfly nymphs and other aquatic
organisms cannot survive. This will cause the aquatic organisms become extinct over the time. At high
BOD levels, organisms such as macroinvertebrates that are more tolerant of lower dissolved oxygen such
as leeches and sludge worms may appear and become numerous.
Therefore, from the result obtained the most polluted water is drain water which have high level
of BOD compare to the other water sample. Drainage water is no different from any other water supply
and is always usable for some purpose within certain quality ranges. Beyond these limits, drainage water
must be disposed of in a manner that safeguards the usability or quality of the receiving water for present
established and potential uses.
Surface and subsurface drainage water from agriculture is normally degraded compared
with the quality of the original water supply. Drainage water that flows over or through the soil
will pick up a variety of dissolved and suspended substances including salts, organic compounds
8
9. and soil particles. Management for safe reuse and disposal requires an understanding of the
characteristics of the drainage water, and a matching of those characteristics to the environmental
protection needs of the reuse or disposal area. Sometimes, characteristics of drainage water have
a potential on environmental contaminant.
Conclusion:
The drain water has high BOD level which is 0.963 mg/L while, the lowest BOD level is distilled
water with the value 0.412 mg/L. It can be identified that the high BOD level of water is the most
polluted.
Enhance
The chemical, physical, and biological aspects of water quality are interrelated and must be
considered together. For example, higher water temperature reduces the solubility of dissolved oxygen,
and may cause a dissolved oxygen shortage that kills more sensitive fish species. The rotting fish
carcasses may contribute to a bacterial bloom that makes some human swimmers or boaters ill.
Water quality is highly variable over time due to both natural and human factors. Water
temperature, photosynthetic activity, and flows vary with season. Therefore, the flow and suspended
sediment can vary daily with rainfall. Nutrients loads can vary with season like homeowners fertilizing in
the spring flow from the runoff mechanisms affect pollutant washoff and human management like
nitrogen is released after a clear cut.
Question:
Figure 1 Figure 2
9
10. 1. From the picture above, what are the phenomenon occurred?
Oil spill in the sea.
2. What are the sources of pollution?
-Careless discharge of water heated, for example industrial places.
-Removal of shading vegetation.
3. What are the effects of this phenomenon?
-The effect on this phenomenon is oil spills can have widespread effects on nearly all
Creatures that come into contact with it, from algae to migratory birds, to marine
mammals.
-The main problem caused by water pollution is that it kills life that inhabits water-based
ecosystems. Dead fish, birds, dolphins, and many other animals often wind up on
beaches, killed by pollutants in their habitat.
-Pollution disrupts the natural food chain as well. Pollutants such as lead and cadmium
are eaten by tiny animals. Later, these animals are consumed by fish and shellfish, and
the food chain continues to be disrupted at all higher levels.
-Eventually, humans are affected by this process as well. People can get diseases such as
Hepatitis by eating seafood that has been poisoned.
-Ecosystems can be severely changed or destroyed by water pollution. Many areas are
now being affected by careless human pollution, and this pollution is coming back to
hurt humans.
4. Give one way to solve the problem.
Bioremediation is the process that uses microorganisms, fungi, green plants or their
enzymes to return the natural environment altered by contaminants to its original
condition. In general approach is the cleanup of oil spills by the addition of nitrate or
sulfate fertilizers to facilitate the decompositions of crude oil by bacteria.
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11. References:
Delft (1999). Understanding biochemical oxygen demand test. New Delhi: India.
G.C Delzer and S.W. McKenzie (2003). Five days biochemical oxygen demand. United
States.
https://docs.google.com/present/view?id=djc74gw_201d7z7z3gj
http://www.mpcd.info/index.php?option=com_content&view=article&id=158&Itemid=1
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