ENVIRONMENTAL ENGINEERING

LAB REPORT

Submitted To: Mr. Hafiz Mudaser Ahmad

Submitted By: Ali Ahmad (2018-CH-242)

Abdul Rehman (2018-CH-254)

Abdul Salam (2018-CH-282)

Department of Chemical Polymer and Composite Material Engineering,

University of Engineering and Technology Lahore, KSK Campus
 Table of Content

Laboratory Layout .........................................................................................................................................2

Introduction to Lab Equipment .....................................................................................................................3
Reverse Osmosis Unit ................................................................................................................................... 6
Experiment # 01 ............................................................................................................................................8
Aeration Unit ..............................................................................................................................................12
Experiment # 02 .........................................................................................................................................14
Experiment # 03 .........................................................................................................................................17
Experiment # 04 Water Test Parameters...................................................................................................22
Experiment # 05 Iron test...........................................................................................................................25
Experiment # 06 Alkalinity Test...................................................................................................................28
Experiment # 07 Chloride Test....................................................................................................................33
Experiment # 08 Hardness test...................................................................................................................36
Experiment # 09 Sulphate Test....................................................................................................................38
Experiment # 10 Turbidity Test....................................................................................................................40
Experiment # 11 Sedimentaion Test...........................................................................................................46

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 Laboratory Layout

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 Entry
Auxiliaries
Door

RO
Biological
Apparatus
Main Desk Safety unit

Refrigerator
Sedimentation
Assembly
Unit

Deep bed
filter column Flocculator

Aeration Flocculation
unit
tank

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 Introduction to Lab Equipment

Biological Safety Cabinet:

A biosafety cabinet (BSC)—also called a biological safety cabinet or microbiological safety cabinet—is an
enclosed, ventilated laboratory workspace for safely working with materials contaminated with (or
potentially contaminated with) pathogens requiring a defined biosafety level. Several different types of
BSC exist, differentiated by the degree of biocontainment required. BSCs first became commercially
available in 1950. The primary purpose of a BSC is to serve as a means to protect the laboratory worker
and the surrounding environment from pathogens. Cabinets need to be maintained on a regular schedule.
During this certification check, the airflow and the filter capacities are verified. The filters have a limited
lifespan - determined by the air quality within the laboratory space and the amount of particles and
aerosols generated inside the BSC' work zone.

fig. 1: Biological Safety Cabinet

Sedimentation Unit:
The Sedimentation unit provides a facility for studying the basic physical processes involved in
sedimentation. It is used to study:

❖ Effect of initial concentration on sedimentation rates

❖ Construction of settling-rate curves from a single batch test
❖ Effect of initial suspension height on sedimentation rates
❖ Effect of particle size distribution
❖ Use of flocculating additives

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 Fig. 2: Sedimentation Unit

Digital Flocculator :
The Digital Flocculator allows for the well-known 'jar tests' to be conducted on water samples requiring
treatment to determine the correct coagulant dosage on a laboratory scale as a prelude to full-scale plant
operation. It is used for:

❖ Determination of optimum coagulant dosage

❖ Determination of optimum pH
❖ Effect of mixing time and intensity on aggregation
❖ Coagulation tests in conjunction with activated carbon ❖ Coagulation tests in conjunction with
filterability tests

Fig. 3: Digital Flocculator

Aeration Unit
The purpose of the Aeration Unit is to permit study of the oxygen transfer characteristics of diffused air
systems and the physical and chemical parameters that influence their oxygenation capacity. These

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studies are a necessary prelude to the understanding of the biological treatment of waste water. It is used
to determine:

❖ Effects of oxygen transfer under non-steady state conditions

❖ Measurement of the absorption coefficient Ks and the oxygenation capacity R ❖ The effect on
Ks and R of:

Figure 1 Aeration Unit

Deep Bed Filter Column :

A Deep Bed filter may be defined as a granular filter for removal of TSS from secondary treatment effluent
using a media depth of at least four feet at a filtration rate of more than 2 gpm/ft2. Coarse media is
normally used to encourage deep penetration of solids into the media bed. This allows for longer filtration
runtimes. Simultaneous air and water backwashes are used to ensure cleaning of the filters as required.
Severn Trent Services offers gravity, pressure and modular filters and pre-assembled gravity deep bed
filters.

Fig. 5: Deep Bed Filter Column

Refrigerator:
The working principle of a refrigerator (and refrigeration, in general) is very simple: it involves the removal
of heat from one region and its deposition to another. The basic steps in refrigeration are:

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 ❖ The coolant is a pressurized liquid as it enters the expansion valve. As it passes through, the
sudden drop in pressure makes it expand, cool, and turn partly into a gas As the coolant flows
around the chiller cabinet (usually around a pipe buried in the back wall), it boils and turns
completely into a gas, and so absorbs and removes heat from the food inside.
❖ The compressor squeezes the coolant, raising its temperature and pressure. It's now a hot, high
pressure gas.
❖ The coolant flows through thin radiator pipes on the back of the fridge, giving out its heat and
cooling back into a liquid as it does so.
❖ The coolant flows back through the insulated cabinet to the expansion valve and the cycle repeats
itself. So heat is constantly picked up from inside the refrigerator and put down again outside it.

Fig. 6: Refrigerator

Reverse Osmosis:

Reverse osmosis (RO) is a water purification technology that uses a partially permeable membrane to
remove ions, molecules and larger particles from drinking water. In reverse osmosis, an applied pressure
is used to overcome osmotic pressure, a colligative property, that is driven by chemical potential
differences of the solvent, a thermodynamic parameter. Reverse osmosis can remove many types of
dissolved and suspended chemical species as well as biological ones (principally bacteria) from water, and
is used in both industrial processes and the production of potable water. The result is that the solute is
retained on the pressurized side of the membrane and the pure solvent is allowed to pass to the other
side. To be "selective", this membrane should not allow large molecules or ions through the pores (holes),
but should allow smaller components of the solution (such as solvent molecules, i.e., water, H2O) to pass
freely.

A Review Of Reverse Osmosis Water Filter System

The existence of Reverse Osmosis is calculated to range four hundred years ago, and this method had
been known to be an important method of water filtration. Through the years of use, the process had

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evolved and developed as it started to become an accessible method for everyone. However, this process
is not invincible, as contaminants increases, the effects of the said method may decrease.

Reverse Osmosis existed and was welcomed by many as the best alternative for the expensive distillation
process, and it is continuously embraced as one of the most effective and safest ways to treat drinking
water. Other than being cheaper, it is found to be more effective than distillation on getting rid of
dissolved chemicals on water. The method is ideal for filtering out heavy metals and chemicals such as
nitrates, fluoride, sodium, mercury, uranium, lead, radium and many more. It could also get rid of harmful
bacteria, chlorine, and other hazardous sediments.

Reverse Osmosis Filters are one-of-a-kind filtering systems that have detailed and traditional purifying
activities. With its purpose of removing unidentified particles in water, this filtering item carefully and
meticulously pulls out any harmful chemicals which may endanger the health of the consumer who drinks
water from it.
Invented during the 1970s, Reverse Osmosis Filters helped and aided lots of people by ensuring the safety
of the water they drink. Its membrane-like structure has specialized qualities in draining out the particles
mixed with the water it filters. The impurities found and filtered are then separated and slashed out in the
system of filtered water. This is how Reverse Osmosis Filter works in the household for how many decades.

With its natural process that forces the solvent to produce safe and clean water, Reverse Osmosis Filter
also provides the conversion of seawater and brackish water into a sterilized one.
It did a huge contribution in applying it to different sectors like medical, domestic and industrial
purposes. This filtering equipment is long proven to be good and trusted by the majority of consumers in
the market.

Its traditionalized process still maintains it's effective with the service it delivers to the water filtering
industry. In fact, this water filter facility stands out with the other ones because of its long-term duration
of service to the consumers in the market.

Introduction:
Water, a limited finite resource, vital for the very existence of life on earth and a necessity for economic
and social development and for environmental sustainability, is becoming a scarce commodity. This is
caused by the population growth, the change of lifestyle, water pollution, in efficient use of water and
climatic changes with more frequent extreme events such as droughts and floods. Where the availability
of water cannot be increased by using conventional resources or by recycling or cannot be made available
by demand management methods, the desalination of sea or brackish water offers an alternative solution.

The process utilizes several different technologies for separation. Two of the most commercially important
technologies are based on the multi-stage flash (MSF) distillation and reverse osmosis (RO) processes.

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 Figure 7: Chart showing portions of total desalination capacity by source water

Reverse Osmosis:
In the reverse osmosis (RO) process, the osmotic pressure is overcome by applying external pressure
higher than the osmotic pressure on the feed water. Thus, water flows in the reverse direction to the
natural flow across the membrane, leaving the dissolved salts behind with an increase in salt
concentration. No heating or phase change is necessary. The major energy required for desalting is for
pressurizing the seawater feed. A typical large seawater RO plant consists of four major components: feed
water pre-treatment, high pressure pumping, membrane separation, and permeate post-treatment.

Reverse Osmosis works by using a high pressure pump to increase the pressure on the salt side of the RO
and force the water across the semi-permeable RO membrane, leaving almost all (around 95% to 99%) of
dissolved salts behind in the reject stream. The amount of pressure required depends on the salt
concentration of the feed water. The more concentrated the feed water, the more pressure is required to
overcome the osmotic pressure.

The desalinated water that is demineralized or deionized, is called permeate (or product) water. The water
stream that carries the concentrated contaminants that did not pass through the RO membrane is called
the reject (or concentrate) stream.

Figure 8: Working of RO

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Basic Components and Terminology:

Feed water: Supply water that is fed into the RO system to be treated

Permeate: A portion of the feed water that passes through a series of membranes and is returned as
purified water.

Concentrate: A portion of the feed water that is rejected by the membrane and contains the solution of
impurities that have been filtered out of the permeate.

Water flux: The rate of permeate production typically expressed as the rate of water flow per unit area of
membrane (e.g., gallons per square foot per day)

Recovery rate: The ratio of permeate flow to feed water flow, which indicates the overall water efficiency
of the system

Figure 2 Reverse Osmosis System

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Types of Membranes:
Following are the types of membranes;
Table 1: Membranes and their transfer mediums

Advantages:

Improve Taste: RO filtration improves taste, odor and appearance of water by removing contaminants
that cause taste and odor problems.

Saves Money: With an RO system, you can cancel your water delivery service and stop purchasing cases
of bottled water. Reverse Osmosis filtration provides “better-than-bottled water” quality water for just
pennies per gallon.

Removes Impurities: RO systems remove pollutants from water including nitrates, pesticides, sulfates,
fluoride, bacteria, pharmaceuticals, arsenic and much more. An RO systems’ carbon filter will also remove
chlorine and chloramines.

Simple Maintenance: RO systems have very few moving or replaceable parts make RO systems easy to
clean and service.

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Limitations:

❖ Higher operating costs;

❖ High energy costs;
❖ Higher discharge volumes, higher concentrate volume than NF;
❖ High operating pressure than NF;
❖ Requires supply water to be treated (pre-filtration 0.1 - 20 microns);
❖ Reverse osmosis normally provides water with aggressive pH level (in other words, a low or high
pH in water with few ions);
❖ Membranes sensitive to free chlorine.

Experiment No.01

Objective: Treatment of water using Reverse Osmosis Equipment

Apparatus: Lab Scale RO Equipment

Principle:
When two aqueous solutions of different concentrations are separated by a semi-permeable membrane,
the solvent flows through the membrane, towards the more concentrated solution, due to osmotic
pressure. When a counter pressure is applied to the concentrated solution, in order to overcome the
osmotic pressure, the flow of the solvent changes its direction or is reversed.

Procedure;

❖ The valve has a tube that attaches to the inlet side of the RO pre filter. This is the water source
for the RO system
❖ Water from the cold water supply line enters the Reverse Osmosis Pre Filter first. There may
be more than one pre-filter used in a Reverse Osmosis system. The most commonly used
prefilters are sediment filters. These are used to remove sand silt, dirt and other sediment.
Additionally, carbon filters may be used to remove chlorine, which can have a negative effect
on membranes.
❖ The Reverse Osmosis Membrane is the heart of the system. The most commonly used is a
spiral wound of which there are two options: the CTA (cellulose tri-acetate), which is chlorine
tolerant, and the TFC/TFM (thin film composite/material), which is not chlorine tolerant.
❖ After the water leaves the RO storage tank, the product water goes through the post filter (s).
The post filter (s) is generally carbon (either in granular or carbon black form). Any remaining
tastes and odors are removed from the product water by post filtration.

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 ❖ To conserve water, the RO system has an automatic shutoff valve. When the storage tank is
full (this may vary based upon the incoming water pressure) this valve stops any further water
from entering the membrane, thereby stopping water production. By shutting off the flow
this valve also stops water from flowing to the drain. Once water is drawn from the RO
drinking water faucet, the pressure in the tank drops and the shut off valves opens, allowing
water to flow to the membrane and waste-water (water containing contaminants) to flow
down the drain.
❖ A check valve is located in the outlet end of the RO membrane housing. The check valve
prevents the backward flow or product water from the RO storage tank. A backward flow
could rupture the RO membrane.
❖ The standard RO storage tank holds up to 2.5 gallons of water. A bladder inside the tank keeps
water pressurized in the tank when it is full.
❖ The RO unit uses its own faucet, which is usually installed on the kitchen sink. In areas where
required by plumbing codes an air-gap faucet is generally used.
❖ This line runs from the outlet end of the Reverse Osmosis membrane housing to the drain.
This line is used to dispose of the impurities and contaminants found in the incoming water
source (tap water). The flow control is also installed in this line.

Results:

After taking samples we checked the parameters. That are shown in table.
TDS (ppm) TEMPERATURE °C

INLET 295 16.9

OUTLET 32 14.7

CONCENTRATE 337 15.1

Conclusion:
The factors that affect the performance of a Reverse Osmosis System are:

• Pressure
Solute rejection rises with pressure, since solvent flux increases. Higher flow of water through
the membrane will tend to promote more rapid fouling, the single greatest cause of
membrane failure.

• Water Temperature
RO permeate flow is strongly dependent on the temperature of the feed water. The higher
the temperature the higher the permeate flowrate. Lower viscosity makes it easier for the

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 water to permeate through the membrane barrier For every 1˚C the permeate flow will
increase~3%

References:

1) Pontius F. W., "Water Quality and Treatment", A Handbook of Community Water Supplies, 4th
Edition, Mc-Graw-Hill, Inc..

2) Taylor J. S., Et Al, "Assessment of Potable Water Membrane Applications and Research Needs",
AWWA, Research Foundation, December.

3) Sudak R. G., Dunivin W., and Rigiby M. G., "Procurement of New Reverse Osmosis Membrane and
Pressure Vessels", Technical Proceeding of the NWSIA Biennial Conference, Vol. 2, 1988.

4) Rowley L. H. "A Screening Study of 12 Biocides for Potential Cellulose Acetate RO Membranes",
Technical Proceeding of the NWSIA Biennial Conference, Vol. 2.

5) Gamal Khedr M., "Progressive Development of Fouling In Water Desalination By Reverse Osmosis,
Forms And Mechanism", Third International Water Technology Conference, Alexandria, Egypt, pp.
111123, March 1998.

6) Chapman-Wilbert M. "The Desalinating and Water Treatment Membrane Manual", A Guide To

Membranes For Municipal Treatment, U.S. Dept. of Interior, Applied Science Branch, Research and
Laboratory Division, September.

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 AREATION UNIT

Theoretical background:
Wastewater aeration is the process of adding air into wastewater to allow aerobic biodegradation
of the pollutant components. It is an integral part of most biological wastewater treatment systems. Unlike
chemical treatment which uses chemicals to react and stabilize contaminants in the wastewater stream,
biological treatment uses microorganisms that occur naturally in wastewater to degrade wastewater
contaminants. In municipal and industrial wastewater treatment, aeration is part of the stage known as
the secondary treatment process. The activated sludge process is the most common option in secondary
treatment. Aeration in an activated sludge process is based on pumping air into a tank, which promotes
the microbial growth in the wastewater. The microbes feed on the organic material, forming flocks which
can easily settle out. After settling in a separate settling tank, bacteria forming the "activated sludge"
flocks are continually recirculate back to the aeration basin to increase the rate of decomposition.

Aeration working:
Aeration provides oxygen to bacteria for treating and stabilizing the wastewater. Oxygen is
needed by the bacteria to allow biodegradation to occur. The supplied oxygen is utilized by bacteria in the
wastewater to break down the organic matter containing carbon to form carbon dioxide and water.
Without the presence of sufficient oxygen, bacteria are not able to biodegrade the incoming organic
matter in a reasonable time. In the absence of dissolved oxygen, degradation must occur under septic
conditions which are slow, odorous, and yield incomplete conversions of pollutants. Under septic
conditions, some of the biological process convert hydrogen and sulfur to form hydrogen sulfide and
transform carbon into methane. Other carbon will be converted to organic acids that create low pH
conditions in the basin and make the water more difficult to treat and promote odor formation.
Biodegradation of organic matter in the absence of oxygen is a very slow biological process.

Figure 3 Aeration Unit

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Types of Aerators:
Aerators fall into two general categories. They either introduce air into the water or water into the air.
The water-to-air method is designed to produce small drops of water that fall through the air. The air-
towater method creates small bubbles of air that are injected into the water stream. All aerators are
designed to create a greater amount of contact between the air and water to enhance the transfer of the
gases.

Water into Air:

In this category we have the following Aerators
1) Cascade aerators

2) Cone aerators 3) Slat and Coke aerators Air into

Water:
In this category we have the following Aerators
1) Pressure aerators
2) Air stripping

Operational Testing:
Three basic control tests are involved in the operation of the aeration process:
1) Dissolved oxygen

2) pH
3) Temperature
The concentration of dissolved oxygen can be used to estimate whether the process is over or under
aerated. The pH test will give an indication of the amount of carbon dioxide removal. pH increases as the
carbon dioxide is removed. pH can also be used to monitor the effective range for hydrogen sulfide, iron,
and manganese removal. The temperature is important as the saturation point of oxygen increases as the
temperature decreases. As water temperature drops, the operator must adjust the aeration process to
maintain the correct DO level.

Limitations:
Temperature significantly affects the efficiency of air stripping processes. Therefore, these processes may
not be suitable for use in colder climates. Theoretically, at 68°F the carbon dioxide content of the water
can be reduced to 0.5 ppm by aeration to equilibrium conditions. This is not always practical from an
economic standpoint, and reduction of carbon dioxide to 10 ppm is normally considered satisfactory.
Although removal of free carbon dioxide increases the pH of the water and renders it less corrosive from
this standpoint, aeration also results in the saturation of water with dissolved oxygen. This does not
generally present a problem when original oxygen content is already high. However, in the case of a well

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water supply that is high in carbon dioxide but devoid of oxygen, aeration simply exchanges one corrosive
gas for another.

Apparatus:
Laboratory aeration unit

❖ Aeration tank
❖ Rota meter
❖ Air pump
❖ Agitator
❖ DO meter with probe
❖ Air inlet diffuser

Experiment # 02:
Objective:
Determine the amount of DO by changing speed of agitator.

Procedure:
❖ Filled the tank with water at 25C
❖ Noted the amount of saturation DO at 250C.
❖ Supplied the air with constant flow rate.

❖ The flow rate of air can be adjusted by using Rota meter.

❖ Inserted probe of DO meter in water tank.
❖ First measured the amount of dissolved oxygen C1 at zero RPM and time t1.
❖ Changed the rpm (revolutions per minute) of agitator and measure the amount of dissolved
oxygen
❖ Repeated this procedure by changing speed of agitator after every 3min

Calculations:
Initial flow rate of Air = 1 L/min
PH = 7.8
Temperature = 25 C

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Agitator Speed = 0 rpm
Initial Dissolved Oxygen = 3.65

Table No 1:
NO. OF OBS Agitator Speed rpm DO mg/L Air Flow Rate
L/min

1 300 3.8 1

2 400 4 1

3 500 4.2 1

Agitator Speed v/s DO

4.25
4.2 500, 4.2
4.15
4.1
4.05
4 400, 4
3.95
3.9
3.85
3.8 300, 3.8
3.75
0 100 200 300 400 500 600
Agitator Speed

Graph No 1

Conclusion:

By considering the graph of DO and Rpm it is concluded that by keeping air flow constant and
changing the speed of agitator, amount of dissolve oxygen increases in water.

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 Experiment # 3
Objective:
Determine the amount of DO by changing Air Flow Rate.

Procedure:
❖ Filled the tank with water at 25C ❖ Noted the amount of saturation DO at 25C.
❖ Supplied the air with constant flow rate.
❖ The flow rate of air can be adjusted by using Rota meter.
❖ Inserted probe of DO meter in water tank.
❖ First measured the amount of dissolved oxygen C1 at constant RPM and time t1.
❖ Changed the Air Flow Rate and measure the amount of dissolved oxygen
❖ Repeated this procedure by changing speed of agitator after every 3min

Calculations:
Initial flow rate = 0 L/min

PH = 7.8
Temperature = 25 C

Agitator Speed = Initial

Dissolved Oxygen =
Table No 2:

NO. OF OBS Agitator Speed rpm DO mg/L Air Flow Rate

L/min
1 400 3.8 0.5

2 400 4 1

3 400 4.2 2

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 Air Flow Rate v/s DO
4.25
4.2 2, 4.2
4.15
4.1
4.05
4 1, 4
3.95
3.9
3.85
3.8 0.5, 3.8
3.75
0 0.5 1 1.5 2 2.5
Air Flow Rate

Graph No 2

Conclusion:

By considering the graph of DO and Rpm it is concluded that by increasing air flow and keeping
the speed of agitator constant, amount of dissolve oxygen increases in water.

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 Experiment # 04 Water Testing Parameters

Iron Test:
Introduction:

Iron is one of the most common elements in the Earth's crust and dissolves in underground water.
This carries the iron into the water supply as ground water seeps into aquifers. Iron can be found
in drinking water as ferrous iron which is soluble and ferric iron which is insoluble. You can
determine if you need to have the iron concentration in your water measured by observing its
color and through iron testing kit.

Figure 4 Turbid vs Clear water

Significance and Use:

Generally, ground and surface water contains no more than 1 mg/L (ppm) iron; but due to mining
and industrial drainage, higher levels of iron have been observed. Iron in water appears to be
more of a nuisance than a hazard. The presence of iron can stain laundry and give water a
bittersweet taste. The Hanna Test Kit determines the iron concentration in water by conversion
of the ferrous (Fe2+) state. The test is fast, easy and safe. The color cube makes it simple to obtain
the iron level in water.

Chemical Reaction:

Iron can exist as ferrous (Fe2+) or ferric (Fe3+) ions. The Hanna Test Kit determines total iron
levels in water via a colorimetric method. First all ferric ions are reduced by sodium sulfite to
ferrous ions. Phenanthroline complexes with ferrous ion to form an orange colored solution. The
color intensity of the solution determines the iron concentration.

Testing Kit Components:

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 ❖ HI 3834-0 Reagent packets ❖ 1 color comparator cube ❖ 1 plastic vessel (20 mL).

Procedure:

❖ Remove the cap from the plastic

vessel. Rinse the plastic vessel with
water sample, fill it to 10 mL mark.

❖ Add 1 packet of reagent HI 3834-0

❖ Replace the cap and mix solution until solids dissolve

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 ❖ Remove the cap and transfer the solution into the color comparator cube. Let set for 4
minutes.

❖ Determine which color matches the solution in the cube and record the result as mg/L
(ppm) iron

Precautions:

❖ The chemicals contained in this test kit may be hazardous if improperly handled. Read
Health and Safety Data Sheets before performing the test

References:

❖ 1987 Annual Book of ASTM Standard, Volume 11.01 Water (1), pages 531-535.
❖ Standard Methods for the Examination of Water and Wastewater, 16th Edition, pages
215-219.

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 Hardness Test
Introduction:

Water hardness is the traditional measure of the capacity of water to react with soap, hard water
requiring considerably more soap to produce a lather. Hard water often produces a noticeable
deposit of precipitate (e.g. insoluble metals, soaps or salts) in containers, including “bathtub
ring”. It is not caused by a single substance but by a variety of dissolved polyvalent metallic ions,
predominantly calcium and magnesium cations, although other cations (e.g. aluminium, barium,
iron, manganese, strontium and zinc) also contribute. Hardness is most commonly expressed as
milligrams of calcium carbonate equivalent per litre. Water containing calcium carbonate at
concentrations below 60 mg/l is generally considered as soft; 60–120 mg/l, moderately hard;
120–180 mg/l, hard; and more than 180 mg/l, very hard (McGowan, 2000). Although hardness is
caused by cations, it may also be discussed in terms of carbonate (temporary) and non-carbonate
(permanent) hardness.

Significance and Use:

In history, water hardness was defined by the capacity of water to precipitate soap. The ionic
species in the water causing the precipitation was later found to be primarily calcium and
magnesium. In the present, therefore, water hardness is actually a quantitative measure of these
ions in the water sample. It is also now known that certain other ion species, such as iron, zinc
and manganese, contribute to the overall water hardness. The measure and subsequent control
of water hardness is essential to prevent scaling and clogging in water pipes. The Hanna Hardness
Test Kit makes monitoring easy, quick and safe. The compact size provides the versatility to use
the kit anywhere. The design of the kit makes it easy to handle.
Chemical Reaction:

The hardness level as mg/L (ppm) calcium carbonate is determined

by an EDTA (ethylenediamine- tetraacetic acid) titration. The
solution is first adjusted to a pH of 10 using a buffer solution. The

Figure 5 Scaling in Pipe due to

hardness in water
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indicator chelates with metal ions such as magnesium or calcium to form a red colored complex.
As EDTA is added, metal ions complex with it. After all the free metal ions have been complexed,
an excess EDTA removes the metal ions complexed with the indicator to form a blue colored
solution. This color change from red to blue is the endpoint of the titration.

Testing Kit Components:

• Hardness Buffer, 1 bottle with dropper (30 mL)

• Calmagite Indicator, 1 bottle with dropper (10 mL)
• HI 3812-0 EDTA Solution, 1 bottle (120 mL)
• 1 plastic beaker (20 mL) with cap
• 1 plastic beaker (50 mL) with cap
• 1 syringe (1 mL) with tip

Figure 6 Hardness Testing Kit

Procedure:

❖ Remove the cap from the small plastic beaker. Rinse the plastic beaker with the water
sample, fill to the 5 mL mark and replace the cap

❖ Take the titration syringe and push the plunger completely into the syringe. Insert tip into
HI 3812-0 EDTA Solution and pull the plunger out until the lower edge of the seal is on the
0 mL mark of the syringe

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 ❖ Place the syringe tip into the cap port of the plastic beaker and slowly add the titration
solution dropwise, swirling to mix after each drop

❖ Continue adding the titration solution until the solution becomes

purple, then mix for 15 seconds after each additional drop until the
solution turns blue

❖ Read off the milliliters of titration

solution from the syringe scale and
multiply by 300 to obtain mg/L (ppm)
CaCO 3

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Calculations:

EDTA Solution used = 3.5 ml CaCO3

= 3.5 * 300 = 1050 mg/L

Precautions:

❖ The chemicals contained in this test kit may be hazardous if improperly handled. Read
Health and Safety Data Sheets before performing the test

References:

❖ Standard Methods for the Examination of Water and Wastewater. Annual Book of ASTM
Standard, vol. 11.01, Water (I)

Alkalinity Test
Introduction:

Alkalinity is a measure of the water's ability to neutralize acidity. An alkalinity test measures the
level of bicarbonates, carbonates, and hydroxides in water and test results are generally
expressed as "ppm of calcium carbonate (CaCO3)". The desirable range f or irrigation water is 0
to 100 ppm calcium carbonate. Levels between 30 and 60 ppm are considered optimum for most
plants.

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Significance and Use:

Alkalinity is the quantitative capacity of a water sample to neutralize an acid to a set pH. This
measurement is very important in determining the corrosive characteristics of water due
primarily to hydroxide, carbonate and bicarbonate ions. Other sources of alkalinity can be from
anions that can be hydrolyzed such as phosphates, silicates, borates, fluoride and salts of some
organic acids. Alkalinity is critical in the treatments of drinking water, wastewater, boiler &
cooling systems and soils. The Hanna Alkalinity Test Kit makes monitoring easy, quick and safe.
The compact size gives the user the versatility to use the kit anywhere. The design makes the kit
easy to handle and, except for HI 3811-0, practically prevents accidental injury or damage due to
spills.

Chemical Reaction:

Alkalinity can be measured as Phenolphthalein Alkalinity and Total Alkalinity. The Phenolphtalein
Alkalinity is determined by neutralizing the sample to a pH of 8.3 using a dilute hydrochloric acid
solution, and a phenophthalein indicator. This process converts hydroxide ions to water, and
carbonate ions to bicarbonate ions:

Since bicarbonate ions can be converted to carbonic acid with additional hydrochloric acid, the
Phenophthalein Alkalinity measures total hydroxide ions, but only half of the bicarbonate
contribution. To completely convert the carbonate ions, hydrochloric acid is added until the
sample's pH is 4.5:

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This is known as Total Alkalinity.

Testing Kit Components:

❖ Phenolpthtalein Indicator, 1 bottle (10 mL) with dropper

❖ Bromophenol Blue Indicator, 1 bottle (10 mL) with dropper
❖ HI 3811-0, 1 bottle (120 mL)
❖ 2 calibrated vessels (10 and 50 mL)
❖ 1 calibrated syringe with tip

Figure 7 Alkalinity Test Kit

Procedure:

Determination of Phenolphtalein Alkalinity:

❖ Remove the cap from the small plastic vessel. Rinse the plastic vessel with water sample,
fill to the 5 mL mark and replace the cap

❖ Add 1 drop of Phenolphtalein indicator through the cap port, and mix carefully swirling
the vessel in tight circles. If the solution remains colorless, record the phenophthalein
alkalinity as zero, and proceed with the procedure for the determination of Total
Alkalinity

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Determination of Total Alkalinity:

❖ Remove the cap from the plastic vessel. Rinse the plastic vessel with water sample, fill to
the 5 mL mark and replace the cap

❖ Through the cap port, add 1 drop of Bromophenol blue indicator and mix. If the solution
is yellow, then it is acidic and an acidity test must be carried out (see HI 3820 – Hanna
Acidity Test Kit). If the solution is green or blue, then proceed to next step

❖ Take the titration syringe and push the plunger completely into the syringe. Insert the
tip into HI 3811-0, and pull the plunger out until the lower edge of the plunger seal is
on the 0 mL mark of the syringe

❖ Place the syringe tip into the cap port of the plastic vessel and slowly add the titration
solution dropwise, swirling to mix after each drop. Continue adding titration solution
until the solution in the plastic vessel turns yellow.

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 ❖ Read off the milliliters of titration solution from the syringe scale and multiply by 300 to
obtain mg/L (ppm) CaCO 3

Calculations:

Titration solution H13811-O used= 7ml

CaCO3 = 7 * 300 = 2100 mg/l

Precautions:

❖ The chemicals contained in this test kit may be hazardous if improperly handled. Read
Health and Safety Data Sheets before performing the test

References:

❖ 1987 Annual Book of ASTM Standard, Volume 11.01 Water (1), pages 151-158
❖ Official Methods of Analysis, A.O.A.C., 14th Edition, 1984. Standard Methods for the
Examination of Water and Wastewater, 18th Edition, 1992, pages 445-446

Chloride Test
The presence of free chlorine (also known as chlorine residual, free chlorine residual, residual
chlorine) in drinking water indicates that; a sufficient amount of chlorine was added initially to
the water to inactivate the bacteria and some viruses that cause diarrheal disease ;the water is

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protected from recontamination during storage. The presence of free chlorine in drinking water
is correlated with the absence of most disease-causing organisms, and thus is a measure of the
potability of water

Significance and Use:

In pools and drinking water supplies, chlorination serves to kill or deactivate disease-producing
microorganisms. It can also improve water quality by reacting with ammonia, iron, sulfide and
some organic substances. However, an excessive concentration of chlorine in water can produce
adverse conditions, such as formation of carcinogenic chloroform or other toxins. To maximize
the purpose for chlorination and minimize any adverse effects, it is essential to monitor the
chlorine levels closely. The Hanna Chlorine Test Kit determines the Free chlorine concentration
in water via a color cube. This makes the test kit practical for field use. No iodine or bromine can
be present for this test to work properly.

Chemical Reaction:

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The addition of chlorine to water produces hydrochloric and hypochlorous acids. The
hypochlorous acid acts as the disinfectant and bleaching agent. The formation of chloramines
and nitrogen trichloride will occur if ammonia is present. These are known as bound chlorine.
Total chlorine is measured by a colorimetric method.

The reaction if buffered at approx. 6.3 pH; in presence of an excessive quantity of iodide ions, the
DPD (N,N-diethyl-pphenylenediamine) is oxidized by chlorine producing a reddish color. The
color intensity of the solution determines the total chlorine concentration.

Testing Kit Components:

❖ 1 Color Comparator Cube

❖ Chlorine Reagent 1 (20 mL)
❖ Chlorine Reagent 2 (15 mL)
❖ Chlorine Reagent 3 (15 mL)

Procedure:

❖ Add 5 drops of Chlorine Reagent 1, 2 drops of Chlorine Reagent 3 and 3 drops of Chlorine
Reagent 2 to the color comparator cube

❖ Fill the color comparator cube with sample to the 5 mL mark

❖ Replace the cap and mix by carefully swirling the cube in tight circles
and inverting it several times

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 ❖ Determine which color matches the solution in the vessel and record the results in mg/L
(ppm) total chlorine.

Precautions:

❖ The chemicals contained in this kit may be hazardous if improperly handled. Read the
relevant Safety Data Sheet before performing this test

References:

❖ Standard Methods for the Examination of Water and Wastewater, 20th Chlorine Edition,
1998

Sulfite Test
Sulfite is most commonly found in boilers and boiler feedwater, where it is used to inhibit
corrosion by reducing dissolved oxygen. It may also be found in industrial wastes such as paper

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mill effluents. Sulfite normally is not present in natural waters because it readily oxidizes to
sulfate.

Significance and Use:

There are many reasons to monitor sulfite concentration in water. In industrial applications, a
sulfite concentration of approximately 20 mg/L must be mantained to prevent pitting and
oxidation of metal components as in boiler feed and effluent waters. A high level of sulfite results
in a lowered pH, thus promoting corrosion. The monitoring of sulfite is important in
environmental control. Sulfite ions are toxic to aquatic lifeforms and their ability to remove
dissolved oxygen in water will destroy the delicate balance of ecology of lakes, rivers and ponds.

The Hanna Sulfite Test Kit makes monitoring easy, quick and safe. The compact size gives the user
the versatility to use the kit practically anywhere. The design of the kit makes it practically
impossible to spill the reagents, thereby reducing the possibility of injury or damage to property.

Chemical Reaction:

A iodometric method is used. Iodide ions react with iodate ions in the presence of sulfuric acid
to form iodine (Step 1). The sulfite present in the water sample then reduces the iodine back to
iodide (Step 2). An excess of iodate ions will generate additional iodine, which will form a blue
complex with starch. This color change determines the end point of this titration.

Testing Kit Components:

❖ Sulfamic Acid Solution; 1 bottle with dropper (30 mL)

❖ EDTA Reagent, 1 bottle with dropper (30 mL)
❖ Sulphuric Acid solution, 1 bottle with dropper (15 mL)
❖ Starch Indicator, 1 bottle with dropper (10 mL)
❖ HI 3822-0 Reagent Titrant Solution, 1 bottle (120 mL) ❖ 2 calibrated vessels (20 & 50
mL) ❖ 1 calibrated syringe with tip.

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 Figure 8 Sulfite test Kit
Procedure:

❖ Remove the cap from the small plastic vessel. Rinse the plastic vessel with water sample,
fill to the 5 mL mark and replace the cap

❖ Add 4 drops each of Sulfamic Acid Solution and EDTA Reagent through the cap port and
mix by carefully swirling the vessel in tight circles

❖ Add 2 drops of Sulfuric Acid Solution through the cap port and mix as described before

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 ❖ Add 1 drop of Starch Indicator through the cap port and mix

❖ Take the titration syringe and push the plunger completely into the syringe. Insert tip into
HI 3822-0 Reagent Titrant Solution and pull the plunger out until the lower edge of the
plunger seal is on the 0 mL mark of the syringe

❖ Place the syringe tip into the cap port of the plastic vessel and slowly add the titration
solution dropwise, swirling to mix after each drop. Continue adding titration solution until
the solution in the plastic vessel changes from colorless to blue

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 ❖ Read off the milliliters of titration solution from the syringe scale and multiply by 200 to
obtain mg/L (ppm) sodium sulfite

Precautions:

❖ The chemicals contained in this test kit may be hazardous if improperly handled. Read
Health and Safety Data Sheets before performing the test

References:

❖ 1987 Annual Book of ASTM Standard, Volume 11.01 Water (1), pages 732-736
❖ Standard Methods for the Examination of Water and Wastewater, 20th Edition, 1998,
page 4-173

Turbidity of Water Test

Turbidity is the technical term referring to the cloudiness of a solution and it is a qualitative
characteristic which is imparted by solid particles obstructing the transmittance of light through
a water sample. Turbidity often indicates the presence of dispersed and suspended solids like
clay, organic matter, silt, algae and other microorganisms. So in short turbidity is an expression
of the optical property that causes light to be scattered and absorbed rather than transmitted in
straight lines through the sample.

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Environmental Significance:

When the turbid water in a small, transparent container such as drinking glass is held up to the
light, an aesthetically displeasing opaqueness or milky coloration is apparent. The colloidal
material which exerts turbidity provides adsorption sites for chemicals and for biological
organism that may not be harmful. They may be harmful or cause undesirable tastes and odours.
Disinfection of turbid water is difficult because of the adsorptive characteristics of some colloids
and because the solids may partially shield organisms from disinfectant. In natural water bodies,
turbidity may impart a brown or other color to water and may interfere with light penetration
and photosynthetic reaction in streams and lakes. Turbidity increases the load on slow sand
filters. The filter may go out of operation, if excess turbidity exists. Knowledge of the turbidity
variation in raw water supplies is useful to determine whether a supply requires special
treatment by chemical coagulation and filtration before it may be used for a public water supply.
Turbidity measurements are used to determine the effectiveness of treatment produced with
different chemicals and the dosages needed. Turbidity measurements help to gauge the amount
of chemicals needed from day-to-day operation of water treatment works. Measurement of
turbidity in settled water prior to filtration is useful in controlling chemical dosages so as to
prevent excessive loading of rapid sand filters. Turbidity measurements of the filtered water are
needed to check on faulty filter operation. Turbidity measurements are useful to determine the
optimum dosage of coagulants to treat domestic and industrial wastewaters. Turbidity
determination is used to evaluate the performance of water treatment plants. Turbidity in water
may be caused by a wide variety of suspended matter suspended matter, such as clay, silt, finely
divided organic and inorganic matter, soluble colored organic compounds, and other organisms.
Under flood conditions, great amounts of topsoil are washed to receiving streams. As the

Guidelines:

According to WHO standard 5 NTU is suggested as the turbidity limit for drinking water, while 1
NTU is recommended to achieve the adequate disinfecting safety. According to Bangladesh
Environment Conservation Rules (1997), drinking Water standard for Turbidity is 10 NTU
(Nephelometric turbidity unit).

Principle

Turbidity is based on the comparison of the intensity of light scattered by the sample under
defined conditions with the intensity of the light scattered by a standard reference suspension
under the same conditions. The turbidity of the sample is thus measured from the amount of
light scattered by the sample taking a reference with standard turbidity suspension. The higher
the intensity of scattered light the higher is the turbidity. Formazin polymer is used as the primary
standard reference suspension.
Because of the wide variety of materials that cause turbidity in natural waters, it has been
necessary to use an arbitrary standard. The original standard chosen was; 1 mg SiO2/L =1 unit of

39 | P a g e
turbidity. The silica used had to meet certain specifications as to particle size. The Jackson candle
turbidimeter has been replaced by more reliable, sensitive, and easier to use instruments that
depend upon the principle of nephelometry. As a standard reference material, Silica has been
replaced by formazin polymer. The formazin suspensions were first calibrated against the Jackson
candle turbidimeter. The standard nephelometry procedure is now reported in nephelometric
turbidity units (NTU). Because the basic principles difference for Jackson candle turbidimeter
method and nephelometric method, results got from the two methods can vary widely. In order
to avoid any confusion this may cause, turbidity measurements by the standard nephelometry
procedure are now reported in nephelometric turbidity units (NTU), and the other one is
reported in Jackson candle turbidimeter units (JTU). 40 NTU are about equivalent to 40 JTU. The
applicable range of this method is 0-40 nephelometric turbidity units (NTU). Higher values may
be obtained with dilution of the sample.

Sample Handling & Preservation:

Water samples should be collected in plastic cans or glass bottles. All bottles must be cleaned thoroughly
and should be rinsed with turbidity free water. Volume collected should be sufficient to insure a
representative sample, allow for replicate analysis (if required), and minimize waste disposal. No chemical
preservation is required. Keep the samples at 4°C. Do not allow samples to freeze. Analysis should begin
as soon as possible after the collection. If storage is required, samples maintained at 4°C may be held for
up to 48 hours.

Precautions:

❖ The chemicals contained in this test kit may be hazardous if improperly handled. Read
Health and Safety Data Sheets before performing the test

❖ The presence of coloured solutes causes measured turbidity values to be low. Precipitation of
dissolved constituents (for example, Fe) causes measured turbidity values to be high.

❖ Light absorbing materials such as activated carbon in significant concentrations can cause low
readings.

❖ The presence of floating debris and coarse sediments which settle out rapidly will give low
readings. Finely divided air bubbles can cause high readings.

Apparatus:
1. Turbidity Meter

Procedure:

1. For testing the given water sample first the reagents are to be prepared. Then the turbidity meter is
required to be calibrated.

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2. To the sample cells, add sample water up to the horizontal mark, wipe gently with soft tissue and place
it in the turbidity meter. Cover the sample cell with the light shield.

3. Check for the reading in the turbidity meter. Wait until you get a stable reading.

Turbidity Test of Water

120

100

80
Grams

60

40

20

0
NTU

References:

❖ 1987 Annual Book of ASTM Standard, Volume 11.01 Water (1), pages 732-736
❖ Standard Methods for the Examination of Water and Wastewater, 20th Edition, 1998,
page 4-173

Sedimentation Test
Sedimentation is the tendency for particles in suspension to settle out of the fluid in which they
are entrained and come to rest against a barrier. This is due to their motion through the fluid in
response to the forces acting on them: these forces can be due to gravity, centrifugal
acceleration, or electromagnetism. In geology, sedimentation is often used as the opposite of
erosion, i.e., the terminal end of sediment.

Background:

As the sediment transport. In that sense, it includes the termination of transport by saltation or
true bed load transport. Settling is the falling of suspended particles through the liquid, whereas
sedimentation is the termination of the settling process. In estuarine environments, settling can
be influenced by the presence or absence of vegetation. Trees such as mangroves are crucial to
the attenuation of waves or currents, promoting the settlement of suspended particles.

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Sedimentation may pertain to objects of various sizes, ranging from large rocks in flowing water
to suspensions of dust and pollen particles to cellular suspensions to solutions of single molecules
such as proteins and peptides. Even small molecules supply a sufficiently strong force to produce
significant sedimentation.

The term is typically used in geology to describe the deposition of sediment which results in the
formation of sedimentary rock, but it is also used in various chemical and environmental fields
to d escribe the motion of often-smaller particles and molecules. This process is also used in the
biotech industry to separate cells from the culture media.

Diagram:

Apparatus:
The sedimentation Studies Apparatus

Stopwatch

Beaker

Calcium carbonate

Water

Procedure:

❖ Select a suitable well mixed powder such as chalk (caco3)

❖ Weight out five separate quantities to make up three equal volume of chalk in
water slurry of say 5% ,7.5% and 10%. Concentrated by weight
❖ Each slurry should be made up a separate beaker and the volume in each should
be identical and sufficient to fill to the top of each sedimentation
❖ Stir each slurry in the separation vessel and then fill each sedimentation tube in
turn starting with the most concentrated

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 ❖ The tube should then be removed from the retaining clips supplied rubber bungs
used to close off the open end each tube should be well shaken to give a constant
suspension

❖ In addition to noting the fall of the interface in each sedimentation tube at

convenient time intervals the rise of the slug interface at the base of tube should
also be recorded.

❖ Graphs of height against time should be plotted

as experiment proceed

Observation & Calculations:

Time Hs Ht

5% 7.50% 5% 7.50%

0 0 0 100 100

5 5.5 10 59 43

10 6 11 58.5 42

15 7 13 58 41

20 9 17 57 39

25 13 22 55 35

30 33 31 51 30

35 64 52 31 21

Graphs:

Water samples should be collected in plastic cans or glass bottles. All bottles must be cleaned thoroughly
and should be rinsed with turbidity free water. Volume collected should be sufficient to insure a
representative sample, allow for replicate analysis (if required), and minimize waste disposal. No chemical

43 | P a g e
preservation is required. Keep the samples at 4°C. Do not allow samples to freeze. Analysis should begin
as soon as possible after the collection. If storage is required, samples maintained at 4°C may be held for
up to 48 hours.

Sludge inetrface for 5%

60

50

40

30

20

10

0
0 5 10 15 20 25 30 35 40

Sludge interface for 7.5%

60

50

40

30

20

10

0
0 5 10 15 20 25 30 35 40

Precautions:

❖ The chemicals contained in this test kit may be hazardous if improperly handled. Read
Health and Safety Data Sheets before performing the test

❖ Measure the weight of lime carefully and pour or in a beaker.

❖ Stirring must be well so that mixture become homogeneous Note the reading carefully and
used the stop watch for time intervals

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 ❖ Label the beakers according to their concentrations so that chance of inaccuracy
decrease

References:

❖ 1987 Annual Book of ASTM Standard, Volume 11.01 Water (1), pages 732-736
❖ Standard Methods for the Examination of Water and Wastewater, 20th Edition, 1998,
page 4-173

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