LAB COURSE FILE CONTENTS - KG Rkgr.ac.in/beta/wp-content/uploads/2018/09/EE-lab-course-file.pdf · Measure acidity and alkalinity of raw water sample and control effects caused by

G. RAVI ASSISTANT PROFESSOR 1

LAB COURSE FILE CONTENTS S.N. Topics Page No.

PART-1 1 Vision, Mission, PEO’s, PO’s & PSOs 2

2 Syllabus (University Copy) 6

3 Course Objectives, Course Outcomes 7

4 Course Prerequisites 9

5 CO’s, PO’s Mapping 10

6 Course Information Sheet (CIS) 11

a). Course Description 11 b). Course Plan 11 c). Additional Experiments 12 d). Marks Distribution 12 e). Evaluation Scheme 12 f). Text books & Reference books 13 7 Micro Lesson Plan 14

8 Lab Manual 15

9 Viva Question and Answers 50

10 Internal -I Question Paper with Key 59

11 Internal -II Question Paper with Key 60

12 Result Analysis 61

PART-2 1 Attendance Register/Teacher Log Book 62

2 Time Table 63

3 Academic Calendar 64

4 Continuous Evaluation – Internal marks 65


PART 1

1. VISION, MISSION, PEO’S AND PO’S

Vision of Civil Engineering Department

To give the world new age civil engineers who can transform the society with their

creative vibe for the sustainable development by instilling scientific temper with ethical

human outlook.

Mission of civil Engineering Department To make the department a centre of excellence in the field of civil engineering and allied

research. To promote innovative and original thinking in the minds of budding engineers to face

the challenges of future.


Program Educational Objectives of Civil Engineering Department

PEO 1

Graduates will utilize the foundation in Engineering and Science to improve lives and livelihoods through a successful career in civil Engineering or other fields.

PEO 2

Graduates will become effective collaborators and innovators, leading or participating in efforts to address Social, Technical and Business challenges.

PEO 3

Graduates will engage in Life-Long Learning and professional development through Self-Study, continuing education or graduate and professional studies in engineering & Business.


Program Outcomes of Civil Engineering Department

PO1 Fundamental engineering analysis skills: An ability to apply knowledge of computing, mathematical foundations, algorithmic principles, and civil engineering theory in the modelling and design of to civil engineering problems.

PO2 Information retrieval skills: An ability to design and conduct experiments, as well as to analyze and interpret data.

PO3 Creative skills: An ability to design, implement, and evaluate a system, process, component, or program to meet desired needs, within realistic constraints such as economic, environmental, social, political, health and safety, manufacturability, and sustainability. Graduates have design the competence.

PO4 Teamwork: An ability to function effectively on multi-disciplinary teams.

PO5 Engineering problem solving skills: An ability to analyze a problem, and identify, formulate and use the appropriate computing and engineering requirements for obtaining its solution.

PO6 Professional integrity: An understanding of professional, ethical, legal, security and social issues and responsibilities. Graduates must understand the principles of ethical decision making and can interpret the ASCE Code of Ethics. Graduates will understand the proper use of the work of others (e.g., plagiarism, copyrights, and patents). Graduates will understand the special duty they owe to protect the public's health, safety and welfare by virtue of their professional status as engineers in society.

PO7 Speaking / writing skills: An ability to communicate effectively, both in writing and orally. Graduates are able to produce engineering reports using written, oral and graphic methods of communication.

PO8 Engineering impact assessment skills: The broad education necessary to analyze the local and global impact of computing and engineering solutions on individuals, organizations, and society.

PO9 Social awareness: Knowledge of contemporary issues. Students are


aware of emerging technologies and current professional issues.

PO10 Practical engineering analysis skills: An ability to use the techniques, skills, and modern engineering tools necessary for engineering practice.

PO11 Software hardware interface: An ability to apply design and development principles in the construction of software and hardware systems of varying complexity.

PO12 Successful career and immediate employment: An ability to recognize the importance of professional development by pursuing postgraduate studies or face competitive examinations that offer challenging and rewarding careers in Civil Engineering

Program Specific Outcomes PSO 1 ENGINEERING KNOWLEDGE: Graduates shall demonstrate sound

knowledge in analysis, design laboratory investigations and construction aspects of civil engineering infrastructure, along with good foundation in mathematics, basic sciences and technical communication.

PSO 2 BROADNESS AND DIVERSITY: Graduates will have a broad understanding of economical, environmental, societal, health and safety factors involved in infrastructural development, and shall demonstrate ability to function within multi disciplinary teams with competence in modern tool usage.

PSO 3 SELF-LEARNING AND SERVICES: Graduates will be motivated for continuous self-learning in engineering practice and/or pursue research in advanced areas of civil engineering in order to offer engineering services to the society, ethically and responsibly.


2. SYLLABUS (UNIVERSITY COPY)

Textbooks: 1. Water supply Engineering, by Santhosh Kumar Garg, Khanna publishers. 2. Chemical analysis of water and soil, by Dr. KVSG Murali Krishna, Reem.


3. COURSE OBJECTIVES, COURSE OUTCOMES

COURSE OBJECTIVES

1. To make the students good aware about water and its importance to human survival. 2. Understand how to classify and analyse various quality parameters of raw water. 3. To make the students to prepare water quality assessment report. 4. To make the students as to suggest required type of treatment to purify raw water. 5. To make the students as analysts to differ quality requirements for industrial waters and

domestic waters.

COURSE OUTCOMES

1. At the end of the course student will able to discuss about importance of water and its quality analysis.

2. Analyse various physico-chemical and biological parameters of water in case of quality requirements.

3. At the end of the course student will be able to assess complete water quality assessment for EIA and domestic supplies.

4. At the end of the course student will suggest various types of treatment methods required to purify raw water with different contaminants.

TOPIC OUTCOMES

Experiment no.

Name of the Experiment Experiment outcome (at the end of this course, the student will be able to)

1 Determination of pH and turbidity

Measure pH and turbidity of water and suggest suitable treatment in case of these parameters present beyond their limits.

2 Determination of conductivity and total dissolved solids

Measure conductivity of water. Calculate concentration of dissolved solids and detect various kinds of ions present in raw water sample

3 Determination of alkalinity and acidity

Measure acidity and alkalinity of raw water sample and control effects caused by them.


4 Determination of chlorides Estimate the concentration of chlorides ions present in raw water sample and detect the amount of pollution.

5 Determination of iron Measure the concentration of iron got dissolved in raw water.

6 Determination of dissolved oxygen

Measure the concentration of dissolved oxygen and detect the purity of raw water.

7 Determination of nitrates Measure the concentration of nitrates present in water and suggest treatment.

8 Determination of optimum dose of coagulant

Estimate amount of coagulant required to treat raw water with coagulation process.

9 Determination of chlorine demand

Estimate the amount of chlorine required for disinfection process

10 Determination of total phosphorus

Measure amount of phosphorous present in water and detect purity of water

11 Determination of B.O.D. Estimate B.O.D. of water and detect purity of water

12 Determination of C.O.D. Estimate C.O.D. of water and detect purity of water

13 Presumptive coliform test Find MPN of coliforms in the given sample of raw water and detect purity of water


4. COURSE PRE–REQUISITES

1. Water supply engineering 2. Environmental chemistry 3. Applied environmental micro biology.


5. CO’s, PO’s Mapping

PO1 PO2 PO3 PO4 PO5 PO6 PO7 PO8 PO9 PO10 PO11 PO12

CO1 3 - - - 2 - - - 3 3 - -

CO2 - - - - - - - - - 2 - 3

CO3 - - - - - - - 2 - - - -

CO4 - 3 - 3 - - 2 - 3 - - -

Note: 1-low, 2-Medium, 3-High


6. COURSE INFORMATION SHEET

6. a) COURSE DESCRIPTION:

COURSE TITLE ENVIRONMENTAL ENGINEERING LAB COURSE CODE AP70192 REGULATION R15-JNTUH

COURSE STRUCTURE LECTURES TUTORIALS PRACTICALS CREDITS

- - 3 2 COURSE CO-ORDINATOR G. RAVI KUMAR, ASSISTANT PROFESSOR, CIVIL

6. b) COURSE PLAN

Division of Experiments List of experiments

Name of the

Equipment

Course outcomes

Analysis of Physical

Parameters

Week-1 1. Determination of pH and Turbidity

Week-2 2. Determination of electrical conductivity and

total dissolved solids

Analysis of Chemical

Parameters

Week-3 3. Determination of acidity/ alkalinity

Week-4 4. Determination of optimum dose of coagulant

Week-5 5. Determination of chlorides

Week-6 6. Determination of chlorine demand

Week-7 7. Determination of iron

Week-8 8. Determination of nitrates

Week-9 9. Determination of total phosphorous

Week-10 10. Determination of BOD

Week-11 11. Determination of COD


Analysis of Biological Parameters

Week-12 12. Determination of MPN

c) Additional Experiments

Division of Experiments List of experiments

Name of the

Equipment

Course outcomes

d) Marks Distribution

Sessional marks End semester exam

Internal marks

There shall be a continuous evaluation during the semester for 25 marks. Day-to-day work in the laboratory shall be evaluated for 15 marks and internal practical examination conducted by the concerned teacher shall be evaluated for 10 marks.

75 25

e) Evaluation Scheme

S .No. Component Duration Marks

1 Day-to-day Evaluation - 15

2 Internal Practical Examination

3hours 10

3 End Semester Examination

3 hours 75


f) TEXT/REFERENCE BOOKS:

T/R BOOK TITLE/AUTHORS/PUBLICATION Text Book 1 Water supply Engineering, by Santhosh Kumar Garg, Khanna publishers.

Text Book 2 Chemical analysis of water and soil, by Dr. KVSG Murali Krishna, Reem.


7. MICRO LESSOR PLAN

S. no. Name of the Experiment Planned date Actual date

1 Introduction about lab 11-7-2018 11-7-2018

2 Determination of pH and turbidity 18-7-2018 18-7-2018

3 Determination of conductivity and total dissolved solids 25-7-2018 25-7-2018

4 Determination of alkalinity and acidity 1-8-2018 1-8-2018

5 Determination of chlorides 8-8-2018 8-8-2018

6 Determination of iron 9-8-2018

7 Determination of dissolved oxygen 16-8-2018

8 Determination of nitrates 23-8-2018

9 Determination of optimum dose of coagulant 29-8-2018 9-8-2018

10 Determination of chlorine demand 6-9-2018 19-9-2018

11 Determination of total phosphorus 12-9-2018

12 Determination of B.O.D. 19-9-2018

13 Determination of C.O.D. 26-9-2018

14 Presumptive coli form test 9-10-2018


8. LAB MANUAL


Expt. No.: 1

Determination of pH and Turbidity 1(A) Determination of pH

AIM: To determine the pH value of a given sample using pH meter. APPARATUS REQUIRED:

1. pH meter.

2. Water sample. PRINCIPLE: pH is measured by a pH meter using a glass electrode which generates a potential varying linearly with

the pH of the solution in which it is immersed. The basic principle of eletrometric pH measurement is

determination of acidity of hydrogen ion by potentiometer by standard hydrogen electrode and a

reference electrode.

REAGENTS REQUIRED: Standard buffer solution of, 1. pH = 4, pH = 7 and pH = 9 PROCEDURE:

1. The protective cover of the pH meter is removed and pH meter is turned on by the switch.

2. Calibrate the pH meter with atleast two standard buffer solution among of pH 4, 7 & 9.

3. Rinse the pH meter thoroughly with deionized distilled water and carefully wipe with a tissue

paper.

4. Rinse the pH meter thoroughly with deionized distilled water and carefully wipe with a tissue

paper.

5. Dip the pH meter in the sample solution and swirl the solution and wait up to one minute for

steady reading.

6. The reading is taken after the indicated value remains constant for about a minute.

RESULT:


The pH value of given sample is ............................ ENVIRONMENTAL SIGNIFICANCE:

1. Lower value of pH (4) will produce sour taste and higher value of pH (8.5) will produce a

bitter taste.

2. Higher values of pH hasten the scale formation in water heating apparatus and also reduce

the germicidal potential of chlorine. High pH induces the formation of trihalomethanes,

which are causing cancer in human beings.

3. pH below 6.5 starts corrosion in pipes. According to BIS water for domestic consumption

should have a pH value between 6.5to 8.5.

1(B) Determination of Turbidity

AIM: To find the turbidity of the given sample. PRINCIPLE: When light is passed through a sample having suspended particles, the scattering of the light; or

absorption of light is generally proportional to the turbidity. The turbidity of the sample is thus

measured from the amount of light scattered by the sample taking a reference with standard turbidity

suspension.

APPARATUS REQUIRED: Nephelon Turbidity Meter PROCEDURE:

1. Clean inside and outside of the graduated glass tube with clear water.

2. Light the candle and pour the sample into the glass tube until the image of the candle flame just

disappears from view.

3. Pouring the sample very slowly when the candles flame becomes faintly visible after the image

has disappeared, the removal of percentage of suspension form the tube should make it again

visible.

4. Note the reading of glass tube against the surface level of suspension when the image has


disappeared from view. This reading gives the turbidity of the given sample directly in ppm.

APPLICATION OF TURBIDITY DATA IN ENVIRONMENTAL PRACTICE:

Turbidity measurements are of particular importance in the field of water supply. They have limited use in the field of domestic and industrial waste treatment. 1. 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. 2. Turbidity measurements are used to determine the effectiveness of treatment produced with

different chemicals and the dosages needed. 3. Turbidity measurements help to gauge the amount of chemicals needed from day-to-day

operation of water treatment works. 4. It helps to prevent excessive loading of rapid sand filters. 5. Turbidity measurements of the filtered water are needed to check on faulty filter operation. 6. Turbidity measurements are useful to determine the optimum dosage of coagulation to treat

domestic and industrial wastes. 7. Turbidity determination is used to evaluate the performance of water treatment plants.

TABULATION:

Sl.No Sample Turbidity

RESULT: Turbidity of the given sample = ……….…. mg/lit.


Expt. No.: 2 Determination of Conductivity and Total dissolved solids

2(A) Determination of Conductivity

AIM: To determine electrical conductivity of the given samples. ELECTRICAL CONDUCTIVITY: The electrical conductivity is a measure of the capacity of a substance or solution to carry electrical current. The conductivity is represented by reciprocal value of electrical resistance in ohms relative to cubic meter of water at 250C. The measured electrical conductivity value is used as an alternate method to estimate the total dissolved solids (TDS) concentration of sample. Electrical conductivity is represented by ‘k’ and its unit is milli siemens per meter (mS/m) or micro mhos per centi meter. PRINCIPLE: Electrical conductivity is determined using the distance between the electrodes and their surface area. According to Ohm’s law, the current through a conductor between two points is directly proportional to the potential difference across the two points.

APPARATUS REQUIRED: Conductivity meter, small beakers REAGENTS REQUIRED:

1. Distilled water or demonized water: The water is to have an electrical conductivity of less than 0.01 mS/m (<0.1 micromho/cm). Boil the water shortly before use to minimize CO2

content (equal to atmospheric equilibrium). 2. 0.01M Standard Potassium chloride solution (KCl): Dissolve 745.6 mg anhydrous KCl (dried

one hour at 1800C) in conductivity water and dilute to 1000mL. This solution has an electrical conductivity of 141.2 mS/m at 250C.

PROCEDURE:

1. Rinse conductivity cell with 0.01M KCl solution. Calibrate the conductivity meter using the KCl reference solution to obtain cell constant.

2. Measure the electrical conductivity of the 0.01M KCl solution at room temperature. 3. Rinse cell with sample. Measure the electrical conductivity of the sample.


4. Rinse cell with deionised water between samples. 5. Thoroughly rinse the cell in distilled water after measurement, keep it in distilled water when

not in use. Observations:

S. No. Sample Electrical Conductivity

RESULT: Electrical conductivity=……………………………..


2(B) Determination of Total dissolved solids (TDS) AIM: To determine the quantity of total dissolved solids present in the given sample PRINCIPLE: Total solids are determined as the residue left after evaporation and drying of the unfiltered sample. APPARATUS REQUIRED:

1. Evaporating dishes 2. Water bath 3. Dessicator 4. Weighing balance 5. Filter paper

PROCEDURE: Total Solids:

1. Wash & wipe the China dish and dry it in a hot air oven for dryness. 2. Measure the initial weights of dishes by using electronic balance. 3. Take 20 ml of sample in a china dish and evaporate in a water bath at 103˚C to 105 C 4. Cool the container to dryness in a desiccator and weigh the dishes again. 5. Note the increase in weight. 6. The amount of Total solids present in the sample is calculated as

The amount of total solids present in the sample = (mg of residue/volume of sample taken) *1000 Total Dissolved Solids

1. Wash & wipe the China dish and dry it in a hot air oven for dryness. 2. Measure the initial weights of dishes by using Electronic balance. 3. Take 20 ml of filtered sample in a china dish and evaporate in a water bath at 103˚C to 105˚

C 4. Cool the container to dryness in a desiccator and weigh the dishes again. 5. Note the increase in weight. 6. The amount of Dissolved solids present in the sample is calculated as,

The amount of total dissolved solids present in the sample = (mg of residue/volume of sample taken) *1000


The difference between the Total solids and the Dissolved Solids gives the Suspended Solids in the sample. Suspended Solids = Total Solids - Dissolved Solids CALCULATION: Total Solids:

Initial weight of the container W1 = ……….. g

Final weight of the container W2 = ……….. g

Weight of residue = W1 - W2 g

mg of residue

Amount of total solids present in the sample =

* 1000

Volume of sample taken

=…………..mg/lit

Dissolved Solids:

Initial weight of the container W1 = ……….. g

Final weight of the container W2 = ……….. g

Weight of residue = W1 - W2 g

mg of residue Amount of dissolved solids present in the sample =

* 1000


=…………..mg/lit

Suspended Solids:

Suspended Solids = Total Solids-TDS = ------------------------ mg/l


RESULT:

1. Amount of Total solids present in the sample = …………..mg/lit

2. Amount of Dissolved solids present in the sample = …………..mg/lit

3. Amount of Suspended solids present in the sample = …………..mg/lit APPLICATION OF TOTAL DISSOLVED SOLIDS DATA IN ENVIRONMENTAL ENGINEERING PRACTICE:

1. Estimation of Total Dissolved solids is useful to determine whether the water is suitable for drinking purpose, agriculture and industrial purpose.

2. The Suspended solids parameter is used to measure the quality of Waste water influent and effluent.

3. Suspended solids determination is extremely valuable in the analysis of Polluted waters. 4. It is used to evaluate strength of domestic wastewater. 5. It is used to determine the efficiency of treatment units.


Expt. No.: 3 Determination of Acidity and Alkalinity

3(A) Determination of Acidity

AIM: To determine the acidity of a given sample. PRINCIPLE: The mineral acids present in the sample which are contributing to mineral acidity can be calculated by

titrating or neutralizing samples with strong base NaOH to pH 4.3.The CO2 and bi-Carbonate that are

present and contribute to CO2 acidity in the sample can be neutralized completely, by contributing the

titration to pH 8.2.

APPARATUS REQUIRED: 1. Burette

2. Pipette

3. Conical flask

REAGENTS: 1. NaOH Solution (0.02 N)

Dissolve 0.8 g of NaOH in distilled water and dilute to 1000 ml

2. Methyl Orange Indicator: Dissolve 50 mg of Methyl Orange powder in distilled water and dilute to

100 ml.

3. Phenolphthalein Indicator: Dissolve 1 g of Phenolphthalein in 100 ml of 95% ethyl alcohol or isopropyl alcohol, and add 100 ml of

distilled water to it and add 0.02 N NaOH solution drop wise until faint pink color appears.


PROCEDURE:

1. Take 20 ml of sample in a conical flask

2. Add 2 drops of methyl orange and the sample turns to pink color.

3. Titrate the sample until the color changes to yellow. 4. Note down the volume of NaOH added (V1).

5. Add 2-3 drops of Phenolphthalein indicator in it and the titration is continued with

NaOH until pink color appears indicating pH 3.3.

6. Note down the volume of NaOH added (V2). OBSERVATION: Burette solution : NaOH (0.02 N) Pipette solution : Sample Indicator : Methyl orange. End point : yellow Indicator : Phenolphthalein End point : Appearance of pink color TABULATION:

Sl.No Volume Methyl orange Indicator Phenolphthalein Indicator

of sample Initial Final NaOH Initial Final NaOH

Burette Burette used Burette Burette used

Reading Reading V1 Reading Reading V1


CALCULATION:

Mineral acidity due to mineral = V1 * N * 50 * 1000

Acids as mg/l of CaCO3


Phenolphthalein acidity due to V1 * N * 50 * 1000

CO2 as mg/l of CaCO3


Total acidity as mg/lit of CaCO3 = Mineral acidity + Phenolphthalein acidity ENVIRONMENTAL SIGNIFICANCE OF CO2 AND MINERAL ACIDITY: -

1. Acidity interferes in the treatment of water.

2. It corrodes pipes.

3. Aquatic life will be affected.

4. Water containing mineral acidity is very unpalatable.

5. Water having acidity more than 50 mg/l can not be used in RCC works. APPLICATION OF ACIDITY DATA IN ENVIRONMENTALENGINEERING PRACTICE: -

1. The amount of CO2 present is an important factor in determining whether removal by

aeration or simple neutralization with lime or NaOH will be chosen as the treatment

method.

2. The size of equipment, chemical requirement, storage spaces, and cost of treatment all depend upon amount of CO2 present.

3. CO2 is an important consideration in estimating chemical requirements for lime or lime soda

ash softening process. RESULT: -

1.Methyl Orange Acidity :……………mg/lit

2.Phenolphthalein Acidity :……………mg/lit

3.Total Acidity :……………mg/lit


3(B) Determination of Alkalinity

AIM: - To determine the alkalinity of the given sample. APPARATUS REQUIRED: - 1.Burette 2.Pipette 3. Conical flask 4.Methyl orange indicator 5. Phenolphthalein indicator PRINCIPLE: - Alkalinity can be obtained by neutralizing OH-, CO3

2-, and HCO3- with standard H2 SO4. Titration to pH 8.3

or decolourization of phenolphthalein indicator will show complete neutralization of OH- and ½ of CO 2- while to pH 4.4 or sharp change from yellow to pink of methyl orange indicator will indicate total alkalinity i.e. OH-, CO3

2- , and HCO3-.

REAGENT PREPARATION: - 1. Standard Sulfuric Acid (0.02 N): -

Dilute 2.8 ml of Con. H2SO4 to one litre (0.1 N). From that, take 200ml of 0.1N H2SO4 and dilute to one litre (0.02 N) 2. Phenolphthalein Indicator: - Add 1 gram of phenolphthalein in 200 ml of distilled water or ethyl alcohol. Then add 0.02 N NaOH in

drop wise till faint pink colour disappears.

3. Methyl orange Indicator: - Dissolve 0.1gram of methyl orange in 200 ml of distilled water. PROCEDURE: - 1. Phenolphthalein Alkalinity: -

1. Take20 ml of sample in a clean conical flask. 2. Add one drop of phenolphthalein indicator and the sample turns pink in colour. 3. Titrate the sample with standard H2SO4 (0.02 N) taken in a burette. 4. The end point is the disappearance of pink colour.

2. Total Alkalinity: - 1. Add one drop of methyl orange indicator to the solution in which

phenolphthalein alkalinity has been determined. 2. Titrate the above sample against standard H2SO4 (0.02 N). 3. The end point is the appearance of pink colour. 4. Repeat the titration to get concordant values.

OBSERVATIONS: -


Phenolphthalein Alkalinity Standard H2SO4 (0.02 N) Vs Water Sample Phenolphthalein as indicator

S. No. Volume of sample

Burette reading Volume of H2SO4 used Initial Final

Volume of H2SO4 * Normality of H2SO4 * 50 * 1000 Total Alkalinity = ------------------------------------------------------------------------ Volume of sample taken

Total Alkalinity Standard H2SO4 (0.02 N) Vs Water Sample Methyl orange as indicator

S. No. Volume of sample

Burette reading Volume of H2SO4 used Initial Final

Volume of H2SO4 * Normality of H2SO4 * 50 * 1000 Total Alkalinity = ------------------------------------------------------------------------ Volume of sample taken


Value of P and T Alkalinity due to

OH- CO32- HCO3

-

P=0 0 0 T

P< 1/2T 0 2P T-2P

P= 1/2T 0 2P 0

P>1/2T 2P-T 2(T-P) 0 P=T T 0 0

APPLICATION OF ALKALINITY IN ENVIRONMENTAL ENGINEERING PRACTICE:

1. Chemical coagulation of water and waste water 2. To find out the quantity of lime and soda ash required for the removal of hardness.

3. To control the corrosion due to acids, natural waters are rendered to alkaline. RESULT: - Total alkalinity present in the given sample: …………mg/l


Expt. No.: 4

Determination of Chlorides AIM: To estimate the amount of chlorides, present in the given sample of water. GENERAL: Chlorides are usually present in the form of Sodium Chloride. These impact a salty taste to water. A

limit of 200 mg/lit of chlorides is usually recommended in water supplies intended for public water

supply. APPARATUS REQUIRED:

1. Burette

2. Pipette

3. Conical flask

4. Measuring jar

5. Standard flask

6. Beakers PRINCIPLE: Chloride ion is determined by mohr’s Method. The water sample is titrated with standard Silver Nitrate

in which Silver Chloride is precipitated at first. Potassium Chromate is used an indicator. The end of

titration is indicated by formation of red Silver Chromate from excess Silver Nitrate.

Ag NO3 + Cl-------> Ag cl + NO3-

2Ag NO3 + K2CrO4------> Ag2CrO4 + 2 KNO3 REAGENTS PREPARATION: 1. Standard Silver Nitrate (0.0141 N) Dissolve 2.396 g of Silver Nitrate in 1000 ml of distilled water. 2. Potassium chromate indicator: Dissolve 5 g of Potassium Chromate in 100 ml of water and add few drops of Silver Nitrate solution

until red precipitate is formed.


PROCEDURE: 1. Take 20 ml of the given sample in a conical flask. 2. Add 2 to 3 drops of Potassium Chromate indicator to get light yellow color. 3. Titrate the sample against silver nitrate solution until the color changes from yellow to brick red. 4. The same procedure is repeated until consistent values are obtained. TABULATION:

Burette solution : Silver Nitrate.

Pipette solution : Given sample

Indicator : Potassium Chromate

End point : yellow to brick red Sl.No Volume of Burette Volume of

sample in Reading Ag NO3 in ml

ml

Initial Final

CALCULATION:

Amount of Chlorides present Volume of Ag NO3 * Normality of AgNO3 in the given sample = * 35.45 *1000 Volume of sample taken


RESULT: Amount of Chlorides present in the given sample =…………. mg/lit APPLICATION OF CHLORIDES IN ENVIRONMENTAL PRACTICE:

1. Determining Chlorides in natural waters are useful in the selection of water supplies for human use.

2. Chloride determination is used to determine the type of desalting apparatus to be used. 3. Chloride determination is used to control pumping of ground water from locations where

intrusion of seawater is a problem. 4. Chlorides interfere in the determination of chemical demand.


Expt. No.: 5 Determination of Iron

AIM: To determine the amount of iron present in the given water sample. PRINCIPLE: The phenanthroline method is the preferred standard procedure for the measurement of iron in water except when phosphate or heavy metal interferences are present. The method depends upon the fact that 1, 10 phenanthroline combine with Fe++ to form an orange-red complex. Its color confirms to Beer’s law and is readily measured by visual or photometric comparison. Small concentration iron can be most satisfactorily determined by colorimetric analysis. It is also based on beer’s law. By measuring the intensities of transmitted or incident light through a colored solution and knowing its optical density or transmission, we can prepare a calibration curve and subsequent concentration can be read. APPARATUS REQUIRED:

1. Colorimeter (510 nm) 2. Spectro photometer, for use at 510mm, providing a light path of 1 cm or longer 3. Nessler tubes, matched, 100ml, tall form. 4. Glass ware like conical flasks, pipettes and glass beads.

REAGENTS:

1. Concentrated Hydrochloric acid 2. Hydroxylamine solution:

Dissolve 10 gm of the salt in 100 ml distilled water. 3. Ammonium acetate buffer solution:

Dissolve 250 gm ammonium acetate in 150 ml distilled water. Add 700-ml con. (Glacial) acetic acid. 4. Sodium acetate solution 5. Phenanthroline solution:

Dissolve 100 mg of the 1, 10 phenanthroline monohydrate salt in 100 ml distilled water. 6. Stock iron solution:

Dissolve 1.404 gm of ferrous ammonium sulphate in a mixture of 20 ml of con. Sulphuric acid and 50 ml distilled water. Dilute to 1 litre. 1 ml of the stock solution = 200 µg iron. From the stock dilute iron standards can be made.

7. Standard iron solution (1ml=10mg Fe) PROCEDURE:

1. Mix the sample and take 50 ml of the water sample. 2. Add 2 ml Con. HCl and 1 ml Hydroxylamine solution and boil the solution so as to reduce the

volume to 20 ml. 3. Add 10 ml ammonium acetate buffer and 2 ml ortho phenanthroline solution and make up to

100 ml.


4. Allow 10 –15 minutes for maximum colour development. 5. Run distilled water blank along with samples. 6. Take the absorbance readings by setting the distilled water blank to 100 % transmission or zero

absorb taking the readings of the colour developed in the sample at 510 nm. 7. Carry out a calibration graph by using the iron standards ranging from 0 to 100 µg Fe / 100 ml

by using 2 ml to 10 ml iron standard solution one ml = 10 µg of Fe and following the procedure as mentioned above.

8. From the calibration curve determine the Iron content. OBSERVATIONS FOR CALIBRATION GRAPH:

Sl.No Iron Standards Colorimeter

(mg/ lit) readings.

CALCULATION: µg Fe Iron (mg / lit) =_____________________ ml of sample taken

RESULT: The Iron content present in the given water sample is = …………… mg / lit.


Expt. No.: 6 Determination of Dissolved Oxygen

AIM: To find the quantity of dissolved oxygen present in the given sample. APPARATUS REQUIRED:

1. BOD Bottle

2. Burette

3. Pipette

4. Conical flask PRINCIPLE: Manganese Sulphate reacts with the alkali to form a white precipitate of Manganese Hydroxide which in presence of

Oxygen gets oxidized to a brown color compound. In the strong medium, Manganese ions are reduced by Oxide ions

which gets converted into Iodine, equivalent to original concentration of oxygen in sample.

Mn++ + 2(OH)- Mn(OH)2 Mn++ + 2(OH-) MnO2 + H2O MnO2 + 2I- + 4H+ Mn2+ + I2 + 2H2O REAGENTS: 1. Sodium thio Sulphate(0.25N): Dissolve 24.82 grams of Sodium thio sulphate in 1 litre of water. Add a pellet of NaOH in to it and dilute the solution 4

times to prepare 0.025N.

2. Alkaline KI solution: Dissolve 100 grams of KOH and 50 grams of KI in 200ml of water. 3. Manganese Sulphate Solution: Dissolve 100ml of MnSO4,4H2O in 200ml of boiled water. 4. Starch indicator: - Dissolve 2 grams of soluble starch and pour 100 ml of water in it and allow to boil for few minutes. After boiling cool the

solution filter & then use.

PROCEDURE:

1. Fill the Sample in a glass-stoppered bottle (BOD Bottle) of known volume. Avoiding any kind of bubbling and

trapping of air bubbles.

2. Add 1ml of each MnSO4 and KI solution. Pour the Reagents to bottom of bottle with help of pipette to ensure

better mixing.

3. Place the stopper and shake the contents well by inverting the bottle. Keep


the bottle for sometime to settle. 4. Add 1-2ml of conc. H2SO4 and shake the bottle well to dissolve the precipitate.

5. Take 20 ml of sample from the solution and titrate it against Sodium thio Sulphate using starch as indicator.

End point is change of color from blue to colourless solution.

TABULATION:

Sl.no Volume of sample

Burette reading (ml)

Volume of Sodium thio sulphate Initial Final

CALCULATION: Volume of Sodium thio Sulphate*N * 8 * 1000 Amount of Dissolved Oxygen (mg/lit) = -------------------------------------------------------------- V2((V1-V)/V1) Where, V1 volume of bottle V Amount of reagent added (4ml) V2 volume of sample taken for titration. ENVIRONMENTAL SIGNIFICANCE:

1. The minimum DO level of 4 to 5 mg/l is desirable for survival of aquatic life.

2. Higher values of DO may cause corrosion of Iron and Steel. 3. Higher temperature, Ammonia, Nitrates, chemicals such as H2S and organic matter reduce DO values.

4. Algae growth in water may release oxygen during its photosynthesis and DO may even shoot up to 30

mg/l.

5. Drinking water should be rich in DO for good taste.


APPLICATION OF DO DATA IN ENVIRONMENTAL ENGINEERING PRACTICE:

1. It is necessary to know DO levels to assess quality of raw water and to keep a check on stream pollution.

2. DO test is the basis for BOD test which is an important parameter to evaluate organic pollution potential

of a waste.

3. DO test is necessary for all aerobic biological wastewater treatment processes to control the rate of

aeration.

4. DO test is used to evaluate the pollution strength of domestic and industrial waste.

RESULT: Amount of Dissolved Oxygen present in the given sample = …………..mg/l


Expt. No.: 7 Determination of Nitrates

AIM: To determine the amount of Nitrate nitrogen in the given sample of water. APPARATUS REQUIRED:

1. Colorimeter. 2. Hot plate. 3. 100 ml volumetric flasks.

REAGENTS: 1. Brucine sulphanilinic Acid solution: Dissolve 1 g of brucine sulphate and 0.1 g of sulphanilic acid in 70 ml hot distilled water and add 3-ml con. HCl and make up to 100 ml. 2. Sulphuric Acid solution: Add 500-ml con. Sulphuric acid to 125 ml distilled water slowly and cool. 3. Sodium chloride solution: Dissolve 300 g of sodium chloride in 1 litre distilled water. 4. Stock Nitrate solution: Dissolve 721.8 mg of potassium nitrate in distilled water and make up to 1 litre.1 ml of this solution will have = 100 mg NO3N. Dilute 10 ml of the stock to 1 litre with distilled water. 1 ml of the solution = 1m g Nitrate (N). PROCEDURE:

1. Take 10-ml sample in a tube and add 2-ml sodium chloride solution, mix thoroughly. 2. Add 10 ml of sulphuric acid solution, cool and add 0.5-ml brucine sulphate reagent. 3. Swirl the tube to get the solutions mixed and place it in a water bath maintaining a temperature of about 95°

C. 4. After 20 minutes remove the tube and cool. 5. Read the yellow colour in the colorimeter at 410 nm. 6. The calibration curve can be plotted using standards ranging from 0.1 to 1 mg / l by diluting 1-10 ml of the

standard nitrate solution to 10ml distilled water and carrying out the estimation. 7. The distilled water blank with reagent can be run for adjustment of Colorimeter to 100 %

transmission or zero absorbance.


OBSERVATION:

Sample Volume of m g of Nitrate Nitrate mg / l

description sample (ml) in the mg / l

CALCULATION:

Nitrate N ( mg / l) 1m g of Nitrate (N)

=------------------------------------ ml of sample

mg / l of Nitrate = mg of NO3 X 4.43

RESULT:

The amount of Nitrate nitrogen in the given sample of water = --------------- mg / l.


Expt. No.: 8 Determination of Optimum dose of Coagulant

AIM: To find the optimum amount of coagulant required to treat turbid water. PRINCIPLE: Metal salts hydrolyse in presence of the natural alkalinity to form metal hydroxides. The divalent cations can reduce the zeta-potential while the metal hydroxides are good absorbents and hence remove the suspended particles. APPARATUS REQUIRED: -

1. Jar test apparatus 2. Beaker 3. Measuring tubes

REAGENTS: - 1. Alum: Dissolve 10 gms of Alum in 100 ml of distilled water. PROCEDURE:

1. Take 0.5 litre of sample in 4 beakers and keep in jar test apparatus. 2. Switch on the motor and adjust the speed of the paddles. 3. Add various doses of Alum (i.e.) 1ml, 2ml, 3ml, 4ml to different beakers. 4. Allow flash mix rapidly for 1minute. 5. Reduce the speed of the paddles and continue it for 10 minutes. 6. Switch off the motor and allow the solution to settle for 20 minutes. 7. Measure the amount of sludge produced at the bottom. 8. Draw the graph between amount of alcohol added to the sludge produced. From that notes the ideal dosage of

coagulant. OTHER METHOD: Collect the sludge without disturbing beaker and find the turbidity


TABULATION: Sl.No Sample detail Dose of Alum Amount

of sludge

ml mg / lit

ml

CALCULATION: 100 ml of Alum solution = 100 gm of alum 10*1000 1 ml of Alum solution contains = --------------------------- 100 = 100 mg of alum In 500ml solution, 1ml of alum added 100*1000 1lit contains = -------------------------------------- 500 = 200mg of alum ENVIRONMENTAL SIGINIFICANCE: 1. Excess dosage of alum may contribute excess Aluminum in drinking water. 2. Less dosage of Alum do not remove turbidity in water, which ultimately increase load on filters. So the optimum

dosage should be added in coagulation process to prevent the above the problems. 3. Coagulation removes not only turbidity but also color, microorganisms, algae, phosphate, taste and odor. APPLICATIONS IN ENVIRONMENTAL ENGINEERING PRACTICE: 1. This test is useful to identify various natural coagulants. 2. It is useful to estimate optimum dosage of coagulants required for raw water and waste waters. RESULT: Optimum dosage of coagulant is = ------------------mg/lit GRAPH: Draw the graph between alum added versus the amount of sludge produced in ml.


Expt. No.: 9 Determination of B.O.D.

AIM: To determine the BOD value of the given water sample. APPARATUS REQUIRED:

1. Incubator 2. BOD Bottle. 3. Burette. 4. Pipette. 5. Conical flask.

PRINCIPLE: The dissolved oxygen content of the sample is determined before and after 5 days incubation at 20° C. The amount of oxygen depleted is calculated as BOD. Sample devoid of oxygen or containing less amount of oxygen are diluted several times with a special type of oxygen dilution water saturated with oxygen, in order to provide sufficient amount for oxidation. REAGENTS FOR DILUTION WATER: 1.Calcium Chloride solution: Dissolve 27.5 g of anhydrous calcium chloride in distilled water and dilute to 1000 ml. 2.Magnesium Sulphate solution: Dissolve 22.5 g of magnesium sulphate in distilled water and dilute to 1000 ml. 3.Ferric Chloride solution: Dissolve 0.15 g FeCl3.6 H2O in distilled water and dilute to 1000 ml. 4. Phosphate buffer solution Dissolve 42.5 g of Di Hydrogen Phosphate in 700 ml distilled water and add 8.8 g of Sodium Hydroxide and 2g of Ammonium Sulphate and the solution is make up to 1000 ml. DILUTION WATER: - High quality organic free water must be used for dilution water. Aerate required volume of water with a supply of clean compressed Air. Add 1 ml each of Calcium Chloride, Magnesium Sulphate, Ferric Chloride, and Phosphate buffer solution to 1 litre of aerated distilled water and mix thoroughly. This is the standard dilution water. PROCEDURE:

1. Take the sample, dilute it with dilution water. 2. Take the diluted sample in 2 BOD bottles. 3. Fill another two BOD bottles with dilution water alone. 4. Immediately find DO of the diluted wastewater sample and dilution water. 5. Incubate the other 2 BOD bottles at 20°C for 5 days. They are to be tightly stoppered to prevent any air

entry in to the bottles. 6. Determine the DO content in the bottles at the end of 5 days.


TABULATION & OBSERVATION: INITIALDAY:

Sl.No Sample Volume of Burette reading Volume of

taken sample

Sodium thio

Initial Final

taken Sulphate

consumed

FINAL DAY:

Sl.No Sample Volume of Burette reading Volume of

taken sample

Sodium thio

Initial Final

taken Sulphate

consumed


CALCULATION: (D0 - D5 – BC) * Volume of the diluted sample BOD in mg/lit = ---------------------------------------------------------- Volume of the sample. Where, D0 = Initial DO of the diluted sample D5 = DO at the end of 5 days for the diluted sample C0 = Initial DO of the Dilution water (Blank) C5 = DO at the end of 5 days for the dilution water (Blank) Blank correction (BC) = C0 -C5 RESULT: The BOD of the given waste water sample = ………… mg/l APPLICATION OF BOD IN ENVIRONMENTAL ENGINEERING PRACTICE:

1. To determine the strength of domestic and industrial sewage. 2. The determination of BOD is used in studies to measure the self-purification capacity of streams and serves

regulatory authorities as a means of checking on the quality of effluents discharged to such waters. 3. BOD of wastes is useful in the design of treatment facilities. 4. It is used to evaluate the efficiency of various treatment units.


Expt. No.: 10 Determination of C.O.D.

AIM: To find out Chemical Oxygen Demand (COD) of a given waste water sample. PRINCIPLE: The organic matter present in sample gets oxidised completely by K2Cr2O7 in the presence of H2SO4 to produce CO2 and H2O. The excess K2Cr2O7 remaining after the reaction is titrated with Ferrous Ammonium Sulphate. The Dichromate consumed gives the O2 required to oxidation of the organic matter. APPARATUS REQUIRED:

1. Reflux Apparatus 2. Hot plate / Heating Mantle 3. Burette

REAGENTS REQUIRED: 1. Standard Potassium di chromate 2. Sulfuric acid 3. Standard Ferrous Ammonium Sulphate 4. Ferroin Indicator 5. Mercury Sulphate

REAGENTS PREPARATION: 1. Preparation of Ferrous Ammonium Sulphate: Dissolve 98 g of ferrous ammonium sulphate in 20 ml of concentrated Sulfuric acid and make up to 1000 ml using distilled water. 2. Preparation of Potassium Di Chromate: Dissolve 12.259 g of Potassium Di Chromate in distilled water and make upto 1000 ml. PROCEDURE:

1. After Dilution take 20 ml of sample in a COD bottle and add 1 pinch of Mercury Sulphate and 1 pinch of Silver Nitrate in to it.

2. Add 5 ml of Potassium Di Chromate solution in to the above solution. 3. Add 5 ml of concentrated Sulfuric acid in to it. 4. Allow the solution in the room temperature for some time. 5. Heat the solution for two hours in the COD Apparatus. 6. After cooling add 40 ml of distilled water in to it. 7. Titrate the solution against Ferrous Ammonium Sulphate use Ferrion as Indicator. 8. The end point is the appearance of wine red color. 9. Repeat the same procedure for Blank Solution (Ordinary water)

COD in the sample (mg/l) = (A-B) * N * 8000/ ml of sample taken where,

A = Volume of FAS used for blank solution. B = Volume of FAS used for blank solution.

N = Normality of FAS


RESULT: Chemical Oxygen Demand of a given sample = ………… mg/l APPLICATION OF COD DATA IN ENVIRONMENTAL ENGINEERING PRACTICE:

1. The COD test is used extensively in the analysis of industrial wastewater. 2. It is particularly valuable in surveys designed to determine and control losses to sewer systems. 3. The test is widely used in the place of BOD in the operation of treatment facilities because of the speed with

which the results can be obtained. 4. It is useful to assess strength of wastes, which contain toxins and biologically resistant organic substances. 5. The ratio of BOD to COD is useful to assess the amenability of waste for biological treatment. Ratio of BOD to

COD greater than or equal to 0.8 indicates that wastewater highly amenable to the biological treatment


Expt. No.: 11 Determination of Chlorine Demand

Aim: Estimation of Chlorine demand in a given sample of water. Methodology: Iodometric method Apparatus: 1. 500 ml cap. Conical flask 2. 250 ml cap. Volumetric flask 3. 10ml and 25 ml pipette 4. 50 ml Burette Reagents Used: 1.Standard Sodium thiosulphate solution of 0.025 N and 0.01 N. 2. Potassium Iodide (KI) crystals. 3. Glacial Acetic Acid. 4. Starch indicator Solution. 5. Bleaching powdersolution. Theory: Chlorine is widely used for disinfection of water and wastewater to eliminate disease causing organisms, taste and odor. Since it is a powerful oxidizing agent and is cheaply available. The chlorine demand of water is the difference between the amount of chlorine applied and amount of free combined or total available chlorine at the end of contact period. The demand varies with amount of chlorine applied, pH and temperature. The smallest amount of residual chlorine considered significant is 0.1 mg/l. In small treatment plants bleaching powder is added as a disinfectant which obtain in the form of hydro chlorite of calcium which sterilize the water when chlorine is added to water it reacts with water as follows: Cl2 + H2O HOCl (Hypochlorous acid) + HCl HOCl

+ OCl- The quantity of HOCl and OCl which is present in water is called available chlorine. The killing efficiency of HOCl is about 40 to 80 times more than that of OCl. It ruptures the cell membrane of microbes. Ca(OCl)2 Ca + 2OCl (Hypochloride ions) OCl- + H+ HOCl (Hypochlorous Acid) Hypochlorous Acid so formed kills the bacteria. The iodometric method considered as the standard against other method. The liberated iodine is titrated against the std. solution of Sodium Thiosulphate. Procedure:

1. Prepare a bleaching powder solution of known concentration of Chlorine. 2. Measure 200ml of water sample for which Chlorine demand has to be found out in a series of 500 ml cap.

conical flask of say 10 Nos.


3. Add 0.2 ml of bleaching powder solution to first flask and then 0.4 ml bleaching powder solution to second flack and so on in ascending order to the successive portion in series.

4. Mix the solution in each flask gently and allow for contact time of about 30 min. for potable water and suitably higher for polluted water and secondary effluents.

5. After the contact period add 5ml of Acetic acid(glacial) and 1 gm of KI crystals and mix. 6. Now add 1 ml of starch indicator to each flask. Blue color formation indicates the presence of excess Chlorine,

no color indicates that Chlorine demand of water is not sufficient. 7. Titrate the sample with 0.01 N Na2S2O3 solutiontill blue color disappears. 8. Record the ml of Na2S2O3 solution consumed and note down the reading.

Tabulation:

Flask No.

Sample taken in ml

Concentration of

BP solution %

BP solution added

Chlorine added

(b) R-Cl in mg/l

Chlorine Demand (a-b) in

mg/l

200ml 1000ml (a)

1.

2.

3.

4.

5.

6.

7.

8.

9.

10.


Results: Sl. No. Parameter Analyzed Results

1. Chlorine demand of given _____________ mg/l

sample of water

Discussion/Comments on Results:


VIVA-VOCE QUESTIONS Expt. No:1 Determination of pH and Turbidity

1. Define pH. The negative logarithmic value of concentration of hydrogen ion concentration in water is known as pH.

2. Define turbidity. The presence of muddiness or dirtiness in water due to suspended matter is known as turbidity of water.

3. What do you mean by pOH? The negative logarithmic value of hydroxyl ion concentration in water is known as pOH.

4. What is pH of a solution if it is acidic? pH of an acidic solution is less than 7.

5. Is pH of pure water affected by rising its temperature? The pH value slightly decreases with the rise in temperature. This is due to increase in degree of dissociation of water with rise in temperature which in turn results in increase in the concentration of hydronium ions.

6. What is the effect of dilution on pH of (i) acidic solution (ii) basic solution? (i) pH of an acidic solution increases on dilution (ii) pH of a basic solution decreases on dilution

7. What is an acid-base indicator? An acid-base indicator is an organic compound which changes its colour with in certain pH range.

8. pH of sodium carbonate solution would be less than 7 or more than 7? More than seven because sodium carbonate, being a salt of strong base and weak acid, gives alkaline due to hydrolysis.

9. Can turbidity be measured? Yes. By using turbidity rod or by using turbidity meters we can measure turbidity.

10. What is an NTU? NTU is an abbreviation for Nephelometric Turbidity Unit. The term Nephelometric refers to the method an instrument uses to measure the amount of light scattered by suspended, particulate or un-dissolved materials in water.

11. What causes turbidity? Causes of Turbidity In natural bodies of water may include: • Phytoplankton • Shoreline particulates • Stirred up bottom sediments • Clays and silts from river inlets • Organic debris from rivers, streams and/or wastewater discharges • Dredging operations • Floods • Abundance of bottom-feeding fish

12. What damage may be caused by too much turbidity? Aquatic life and animals can be harmed by increased levels of turbidity. Reduce light, reduced food growth ƒ Reduced photosynthesis lowers release of oxygen into the water. ƒ Suspended particulates provide good harbor for viruses, bacteria, and protozoa and / or attachment sites for heavy metals like cadmium, mercury and lead, as well as many toxic organic contaminants such as PCBs, PAHs and pesticides.


Expt. No:2 Determination of Conductivity and TDS 1. Define electrical conductivity.

The electrical conductivity is a measure of the capacity of a substance or solution to carry an electrical current. The conductivity is represented by reciprocal value of electrical resistance.

2. What is the unit of conductance? The internationally recommended unit for conductance is Siemans.

3. Define cell constant. The cell constant is defined as the ratio of length between the electrodes to the area of either electrodes. It only depends upon the physical dimension of the cell.

4. What is dilution? Dilution means increasing the volume of solvent in a solution, and hence the volume of solute gets decreased.

5. Define dissolved solids. The remains in water after filtration is called as dissolved solids or dissolved material.

6. What are the sources of dissolved solids in water? Major sources: Na, Ca, Mg, HCO3

-, SO42-, Cl-, etc.

Minor sources: Fe, K, CO32-, NO3

-, Fluoride, Boron, Silica, etc. Expt. No:3 Determination of Acidity/Alkalinity

1. What is acidity? Acidity is the property of water. Acidity is measure by adding particular base to water. Acidity also defined as the amount of base required to neutralize a solution.

2. What is alkalinity? Alkalinity is property of water, which can be measure by adding particular known volume of acid to water. Alkalinity is also defined as the amount of acid required to neutralise a solution.

3. Define buffer capacity? Buffer capacity is the property of buffer solutions under which whose pH does not change with changes in temperature.

4. What are the indicators used in this experiment? Phenolphthalein, methyl orange

5. Give examples for some strong acids. Hydrochloric acid, sulfuric acid, nitric acid and citric acid.

6. Give examples for some strong bases.


Sodium hydroxide, potassium hydroxide, EDTA, etc. 7. What is the permissible limit for alkalinity in drinking water?

200 mg/l. Expt. No:4 Determination of Chlorides

1. What is the WHO guideline value for chlorides? No health-based guideline value is proposed for chloride in drinking-water by W.H.O However, chloride concentrations in excess of about 250 mg/litre can give rise to detectable taste in water. The EPA Secondary Drinking Water Regulations recommend a maximum concentration of 250 mg/1 for chloride ions. The WHO recommended concentration of Cl- ion in potable water is a maximum of 200mg/l.

2. What is the significance of chlorides test for construction purposes? Chloride ions when present in reinforced concrete can cause very severe corrosion of the steel reinforcement. The chloride ions will eventually reach the steel and then accumulate to beyond a certain concentration level. The protective film around the steel is destroyed and corrosion will begin when oxygen and moisture are present in the steel-concrete interface.

3. How chlorides gain access to natural waters? The primary source of chloride is halite (salt) and brines. Anthropogenic (human) sources of chloride include fertilizer, road salt, human and animal waste, and industrial applications.

4. What would be the role of mixed indicator in this titration? Mixed indicator is added in acid-base titration because a mixture of two indicator substances is used to give sharper end-point color change.

Expt. No:5 Determination of Iron

1. Iron and Manganese are generally present in water supplies in which form? Iron and Manganese are generally present in water supplies in the form of hydrated oxide as suspension and bicarbonates as a solution.

2. What concentration of iron will cause unpleasant colour to water? When the concentration of iron is greater than 3, it will result in unpleasant taste and odor, unwanted precipitation and difficulties in manufacturing processes.

3. What is the result of presence of sulphate iron in water? The presence of Sulfate iron in the water results in acidity in water and corrosiveness on iron and brass.

4. Why reddish tinge may present in water? The reddish tinge in the water is due to the presence of iron. Water contains iron by the reaction of CO2 in contact with iron ore forming soluble ferrous bicarbonate.

5. Explain the principle of aeration. By aeration process, dissolved iron is oxidized into ferric oxide, which is insoluble in water.


6. For removal of iron from water, how much amount of oxygen required? The reaction for removal of iron from water is – 4Fe + O2 + 10H2O = 4Fe (OH)3 +8H 1mg of Fe requires 0.14 mg of O2.

7. What is the use of manganese zeolite? When small amounts of iron and manganese are present in water, they are removed by manganese zeolite where iron and manganese are oxidized to insoluble hydrated oxides which are removed by filtration action of zeolite bed.

8. Removal iron from water takes place at what pH? Removal of iron from water takes place at a pH of 8.2. It can be removed in an oxidized condition by softening water by the excess lime process.

Expt. No:6 Determination of Dissolved Oxygen

1. What are the factors upon which solubility of oxygen depends? The factors which affect the solubility of oxygen in water are: temperature, pressure, salinity, aquatic vegetation.

2. Why starch added when light yellow colour appears? 1. The starch stays dark blue right up until it goes clear, unlike most titrations where

the colour gradually moves toward the endpoint. Therefore, it is easy to become complacent during the titration and add an excess amount of titrant (overshooting the endpoint), thinking that you are far from the endpoint because the colour is not changing.

2. Also, starch can be partially decomposed by a large amount of iodine. Therefore, the starch should not be added until the bulk of the iodine has been reduced (titrated out).

3. Write the significance of this test in environmental engineering? 5-6 ppm

Sufficient for most species

< 3 ppm Stressful to most aquatic species

< 2 ppm Fatal to most species

4. What type of titration involved in this test?

Iodometric titration 5. What is azide modification?

If nitrites NO2-1 will present in water, they will change the results because they convert iodide

ions to iodine before performance of experiment. To remove NO2-1 sodium azides are added.


Expt. No:7 Determination of Nitrates

1. Why is nitrate a problem?

Nitrate in drinking water, at high levels, causes "blue baby syndrome" or methemoglobinema. This is an acute illness that can occur in unborn infants and young children.

2. What are the sources of nitrate?

Nitrate is part of the earth's reactive nitrogen cycle. Nitrogen is a key ingredient in synthetic fertilizer. It is also part of any living materials (for example, proteins contain a lot of nitrogen).

3. Where are the nitrate sources?

Nitrate sources are effectively everywhere - agricultural lands, natural lands, urban areas with leaky sewer lines, septic leach fields, and wastewater percolation basins.

4. How much nitrate does an average cow produce?

An average milking cow produces about 1 lb per day of nitrogen in its urine and feces. Cow manure is stored (solids in piles, liquids in storage lagoons) and then land applied. Between 20% and 40% of the excreted nitrogen will end up in the atmosphere, the remainder is land applied on forage crops or other crops.

5. How much nitrogen does a farmer use? Nitrogen fertilizer applications depend, first, on whether the crop can "make" its own nitrogen (alfalfa, beans, other legume crops). If the crop needs an outside source of nitrogen, fertilizer is applied and the amount will depend mostly on the nitrogen demand of the crop.

6. How much nitrate-nitrogen is 10 mg/L (the drinking water limit), when measured in lb of nitrogen per acre-foot of water?

The drinking water limit (10 mg of nitrate-measured-as-nitrogen per liter) is equivalent to 27 lb of nitrate-nitrogen in one acre-foot of water. Groundwater recharge in irrigated agriculture is typically on the order of one acre-foot per acre.

7. Why don't we just use well-head treatment for nitrate in well water used as drinking water?

This can be done and many public water systems have installed well-head treatment systems (either an ion exchange system or a reverse osmosis system). These are not inexpensive to buy and install, and there is a significant ongoing maintenance cost (filter maintenance and replacement).


Expt. No:8 Optimum dose of Coagulant 1. What is coagulation?

Coagulation: It is the process of addition of a chemical to de-stabilize a stabilized charged particle.

2. What is flocculation? It is a slow mixing technique which promotes agglomeration and helps the particles to settle down.

3. What is coagulant you have used? alum

4. What do you mean by the term end point in a titration? End point means completion of the reaction between the two solution, one taken in the titration and the other added drop by drop from the burette.

5. What is redox titration? The reactions which involve simultaneous oxidation and reduction are called redox titrations and the titrations involving redox reactions are called redox titrations.

6. What is permangnometry? Redox titrations involving KMnO4 as the oxidizing agent are called permangnometry.

7. Why is dilute H2SO4 must suitable as compared to HCl and HNO3 in Potassium permanganate titrations? HCl reacts with KMnO4 to liberate Cl2 gas and consumes some KMnO4, higher results are obtained. HNO3 is a stronger oxidizing agent than KMnO4, so it will oxidize Fe +2to Fe+3 so lower results of the titration will be obtained.

8. Why does KMnO4 act as self-indicator? KMnO4 solution is purple in color due to presence of MnO4- ions. In presence of dil. H2SO4 it reacts with reducing agents (Fe+2 or Oxalic acid) and gets reduces to Mn+2 ions. So the color disappears. At the end point, when all the reducing agent has been oxidized, the excess drop of KMnO4 added is not reduced and pink color is observed in the solution. The color is light pink since solution is very dilute.


Expt. No:9 Bio-chemical Oxygen Demand

1. The nitrogenous demand starts after how many days? As the growth rate of nitrifying bacteria is slow, the nitrogenous demand begins after 5 days.

2. Which of the following is correctly matched? a) ZR – Carbonaceous demand b) RE – Nitrogenous demand c) EP – Final demand d) ZP – Combined demand ZP is correctly paired and it represents the combined demand, which includes both carbonaceous and nitrogenous demand.

3. When nitrogenous demand will occur? The carbonaceous demand occurs due to oxidation of ammonia. The nitrogenous demand is also called as the final demand.

4. When carbonaceous demand will occur? The carbonaceous demand occurs due to oxidation of organic matter. The carbonaceous demand is also called as the initial demand.

5. What is second stage of BOD? LP represents the second stage BOD from the given figure. The second stage BOD is also called as the nitrogenous demand.

6. What is the first stage of BOD? ZL represents the first stage BOD from the given figure. The first stage BOD is also called as the carbonaceous demand.

7. Give the relationship between deoxygenation constant and temperature? The value of deoxygenation constant is directly proportional to the temperature. It increases with increase in temperature.

8. How BOD will be computed? BOD = Dissolved oxygen * Dilution factor. Where, Dilution factor = Volume of diluted sewage sample / Volume of undiluted sewage sample.

9. Define BOD. BOD is the amount of oxygen required to oxidize only organic matter in sewage. It is always less than COD as COD oxidizes both organic and inorganic matter.


Expt. No: 10 Chemical Oxygen Demand 1. What is chemical oxygen demand?

The COD is the measurement of the amount of material that can be oxidised in the presence of a strong chemical oxidising agent.

2. What are the advantages of COD test over BOD test? Correlates with BOD in waste with constant composition Toxic materials do not affect oxidants Changes in the COD value between influent and effluent may parallel BOD content and

supplement BOD results Short analysis time

3. What are disadvantages of COD test over BOD test? Interference from chloride ions Some organic compounds are not oxidised completely

4. What is the most suitable use of COD test? Rapid and frequent monitoring treatment plant efficiency and water quality Higher COD will lead to higher pollution of water bodies

5. Name the oxidants used in this experiment? K2Cr2O7 Mn2(SO4)3

6. Why COD values are always higher than BOD values? Chemical oxygen demand (COD) does not differentiate between biologically available and inert organic matter, and it is a measure of the total quantity of oxygen required to oxidize all organic material into carbon dioxide and water. COD measures some additional organic matter such as cellulose, whereas BOD or Biological Oxygen Demand is supposed to measure the amount of food (or organic carbons) that bacteria can oxidize. So, COD values are always higher than the BOD values.

7. Write the application of COD data to environmental engineering field? Chemical Oxygen Demand COD test is a measure of the relative oxygen-depletion effect

of a waste contaminant. Chemical Oxygen Demand COD is extensively used in analysis of industrial waste.

8. What would be the role of silver sulphate in the determination of COD? Silver Sulphate catalyses the reaction and also assists in the oxidation of the nitrogen compounds. The secondary catalyst, Silver Sulfate (AgSO4) assists oxidization of straight-chain hydrocarbons such diesel fuel and motor oil.

9. Give the NEQS for COD.

Sr. No Parameter Existing

Standards

Revised Standards

Into Inland Water

Into Sewage

Treatment Into Sea


1 Chemical Oxygen Demand (COD)1

150 mg/l 150 400 400

Expt. No: 11 Chlorine Demand

1. What is free available chlorine?

The chlorine existing in water as hypochlorous acid, hypochlorite ions, molecular chlorine is termed as free available chlorine.

2. At what pH chlorine exists as molecular chlorine? When chlorine is added to water, the chlorine acts as molecular chlorine only when its pH is less than 5.

3. When pH is 4 to 5, behaviour of chlorine water? When the pH is between 5 and 10, the chlorine in the water acts as hypochlorous acid and hypochlorite ions. As pH increases, the concentration of hypochlorous acid decreases while of hypochlorite ions increases.

4. At what pH, chlorine in water acts as only hypochlorite ions? HOCl <------> H+ + HOCl– Where, HOCl is hypochlorous acid and HOCl– is hypochlorite ions. At pH<10, only HOCl– is produced.

5. The hypochlorous acid is how many times effective as hypochlorite ions. The hypochlorous acid is 80 times more effective as hypochorite ions, so the pH of water to be treated should be less than 7 to prevent the ionization of it.

6. Chlorine which gets consumed in the oxidation of impurities before disinfection? The hypochlorous acid is 80 times more effective as hypochorite ions, so the pH of water to be treated should be less than 7 to prevent the ionization of it.

7. The chlorine, which serve as a disinfectant? When chlorine demand is fulfilled, then chlorine is available s free residual chlorine, which contains hypochlorous acid and hypochlorite ions.

8. What is the chemical formula of bleaching powder? The chemical formula of bleaching powder is Ca (OCl)2. It is called as chlorinated lime.

9. What is hypo-chlorination? The process of chlorination with hypochlorites is called Hypo-chlorination. Hypochlorites are applied to water as a solution by the hypochlorite feeding apparatus.

10. Which type of chloramine is formed when pH of water is 4.4? pH<4.4, then trichloramine is formed and when pH lies in the range 4.4-5, then formed.

LAB COURSE FILE CONTENTS - KG Rkgr.ac.in/beta/wp-content/uploads/2018/09/EE-lab-course-file.pdf · Measure acidity and alkalinity of raw water sample and control effects caused by

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