Environmental Engineering Lab Manual

                                                       EXPERIMENT # 1

Layout of Environment Lab:

List of Instruments:

1. Weighing balance

2. Electric weighing balance

3. Water bath

4. Microscope

5. Fume hood

6. Ignition

7. Spectrometer

8. Dry oven

9. Incubator

10. Furnace

11. Water distillation unit

12. Titration assembly

13. Graded cylinder

14. Chemical bottle 

1. Weighing balance:

                                 “This instrument is used to measure the weight of different samples”

It has accuracy of 0.01g.

2. Electric weighing balance:

                                           “It is an electric device which is also used to measure the weight of samples” its accuracy is 0.1g and has measuring capacity up to 1000g.

3. Water bath:

                 “Its used for maintain the temperature of a sample”

4. Microscope:

                     “An optical instrument used for viewing very small objects, such as mineral samples or animal or plant cells, typically magnified several hundred times”

5.Fume hood:

                   “A fume hood or fume cupboard is a type of local ventilation device that is designed to limit exposure to hazardous or toxic fumes, vapors or dusts”

6.Ignatition:

                 “The instrument which is used to burn the sample”

7.Spectrometer:

                       “An apparatus used for recording and measuring spectra, especially as a method of analysis”

8.Dry oven:

                  “ A heated chamber for drying samples in the laboratory”

9. Incubator:

                       “An enclosed apparatus which provides a controlled and protective environment for their care of different samples in lab such as controlled temperature and enviorment”

10. Furnace:

                        “An enclosed structure in which material can be heated to very high temperatures, e.g. for smelting metals”

11. water distillation unit:

                                          “It contains different instruments such as a source of heat, still pot ,still head, thermometer/boiling point temperature and condenser

12. Titration Assembly:

                                        This instrument is used for titration purposes and it contains Burette, Pipette and Volumetric flask.

13. Graded cylinder:

                                  “It is usually used to measure the quantity of different liquid samples”

14. Chemical bottle:

                                   “It is used to store different chemicals present in the lab”

                                              

    EXPERIMENT # 2

Objective:

To determine the total solids, total dissolved solids, total suspended solids and total settle able solids in a wastewater sample.

Introduction:

Water and waste water consist of pure water along with various dissolved, colloidal and suspended contaminants. The suspended contaminants in turn may be settle able or non-settle able. These contaminants may be either organic or inorganic in nature

 Nature of solids:

Nature of solid are two type which are as following

         a. Organic Solids

         b. inorganic Solids

 The greater the concentration of organic or volatile solids, the stronger will be the wastewater.
A "weak" wastewater is one containing only a small amount of organic solids.

Apparatus:

      a. forceps         b. drying oven             c. toughs

      d. furnace        e. desiccator                f. filtration assembly

      g. filter paper   h. weighing balance   i. china dish

      j.  volumetric cylinder  k. crucible     l. petri dish

  
3. Related theory:

Type of solids:

• total solids
• dissolved solids
• volatile solids
• non-volatile
• suspended solids
• settle-able solids
• non-settle able

Total solids:

                    Total number of solid particles present in waste water.               

Dissolved solids:

                            Solid particles which are found in dissolved form are called dissolved solids

Volatile solids:

                        Solids which are evaporated upon high temperature.

Non-volatile solids:

                               Solid particles which are not evaporated upon heating are non volatile solids.

Suspended solids:

                            Solid particles found in suspended form in water sample are suspended solids.

Settle able solids:

                            Solid particles which settle down but are not dissolved with respect to time are known as settle able solids.

Non-settle able solids:

                                   Solid particles which do not settle down and keep floating in water sample are known as non settle able solids.

Apparatus:

a.Desiccators
b. Drying oven
c. Analytical balance
d. Graduated cylinder
e. Beaker
f. Fiber filter paper
g. Vacuum pump
h. Stop watch
i. Sample

Procedure:

Determination of total solids:

1. Take a pre-weighed china dish and suppose its weight as W1 grams.
2. Now add well shaken 100mL sample in that china dish and place that china dish on steam bath till all sample evaporate.
3. Now place the china dish in oven having temperature of 103-1050c, till complete dryness.
4. After complete dryness, transfer china dish in desiccators to cool down your sample.
5. After cooling, weigh china dish again. Suppose the weight is W2 grams now.
6. By difference between W1 and W2 (W2> W1) we will get weight of residue.
        T.S = (W2 – W1) x 106/volume of sample (ml) = total solids mg/L
        T.S = (W2 – W1) x103/volume of sample (ml) = total solids g/L
        Answers are in terms of mg/L.

Determination of total dissolved solids:

1. Take fiber filter paper and suppose its weight as WF grams and WS after filtration. Now                                  perform vacuum filtration by taking 100 mL well shaken sample.
2. Insoluble residue will be on filter paper, while soluble will be in filtrate.
3. Transfer filtrate in a pre-weighed china dish. Suppose weight of china dish is W3 grams.
4.Perform the procedure of total solids in china dish. Now the weight is W4 (weight of china dish + residue)
                  T.D.S = (W4 – W3)*106/ Volume of sample

Determination of total suspended solids:

1. Now the residue gives us suspended solids
2. Transfer filter paper to a petri dish and place it into an oven at 101-1030C for complete dryness.
3.Then transfer it to desiccators for cooling.
4. Weigh it again now. This is W6 (weight of suspended solids + weight of filter paper).
5. W6 – W5 will give us Wr (which is weight of residue and WF in grams).
            T.S.S = (Wr – WF)*10^3/ Volume of sample(ml) = weight of dissolved solids in g/L

DETERMINATION OF SETTLEABLE SOLIDS:

1. Take well shaken 1L sample and transfer it into Imhoff cone and wait for 2-3 hours.
2. Every soluble particle is not SETTLEABLE only those having specific gravity greater than water will settle down.
3. Now note the volume of settled solids.
4. Convert the answer by using following relationship
1 ml = 1 g

Determination of sludge volume index:

1. Sludge volume index percentage = (settled sludge volume x 1000)/ total suspended solids (multiply by 1000 to convert it into grams).
2. Total suspended include both settle able and suspended so we have to check what percentage of total settle able solids in total suspended solids.
3. More will be SVI more will be the sludge produce.

Volatile and non-volatile solids determination:

1.Take 50 ml of sample on a preheated crucible of wt. Wc
2. Now transfer the crucible to furnace at 5500C, temperature increase gradually at 1000C water will evaporates and total solids will begin to burn.
3.Then their corresponding oxides will be formed and organic compound burn, CO2 will release
4. We continue this reaction till 5500 C and wait for completion of reaction for 30 minutes for the completion of reaction
5. Inorganic are mainly metals and stable at 5500 C.
6. Then cool it on desiccators and weight it again suppose this time it is Wnon
          TNVS = (Wnon – Wc ) x10^3/volume of sample (ml) = total solids g/L
           TVS = TS - TNVS

Observations and calculations:

Total Solids:
Weight of china dish = 51.604 g = W2 g
Weight of china dish + residue = W1 = 51.6984 g
W2 - W1 = 
Total solids = {(W2 - W1) x 10 3} / Volume of sample
Weight of solids =
1.2 Total Dissolved Solids:
Weight of china dish = W3 = 60.5705 g
Weight of china dish + residue = W4 = 60.6289 g
W4 – W3 =
Total dissolved solids = {(W4 – W3) x 10 3} / Volume of sample
Weight of total dissolved solids=
1.3 Total Suspended Solids:
Weight of filter paper= W5 = 0.09 g
Weight of filter paper + residue = W6 = 0.1221 g
W6 – W5 =
Total suspended solids = {(W6 – W5) x 10 3} / Volume of sample =
1.4 Settle able Solids:
Solids in 1 L = 5ml
As 1ml= 1g so settle able solids in the sample = 5 g/l
1.5 Sludge
SVI = Settle able solids (g) x 1000 / suspended solids (mg) =
SVI =

Results:

Total solids = --------------- mg/l
Total dissolved solids = -----------mg/l
Total suspended solids = ------------- mg/l
Settle able solids in the sample = -------------mg/l
SVI = --------------

Environmental significance:

1.The solids tell us about the suitability of water for domestic uses and drinking purposes.

2. Water with total solids contents of 500 mg/l is most desirable for such purposes. Guideline values recommended an upper limit of 1000 mg/l.

3. High TDS levels (>500mg/liter) result in excessive scaling in water pipes, water heaters, boilers, and household appliances such as kettles and steam irons. Such scaling can shorten the service life of these appliances.
4. A high concentration of total solids will make drinking water unpalatable and might have an adverse effect on people who are not used to drinking such water such as taste and gastrointestinal irritation.
5. Total solids also affect water clarity. Higher solids decrease the passage of light through water, thereby slowing photosynthesis by aquatic plants.

Guideline value:

1.The recommended guideline maximum of 500 mg/L is based on taste. Generally water with less than 500 mg/L is regarded as good quality water but values of up to 1000 mg/L can be tolerated. Corrosion may also become a problem with high TDS levels.

Comments and recommendations:

 Exclude large, floating particles or submerged agglomerates of non-homogeneous materials from the sample otherwise it will affect the reading

References:

                    

   Experiment # 3

Determination of alkalinity

Objective:

To find alkalinity of given set of water samples titrating with sulfuric acid.

Introduction:

                   Alkalinity roughly refers to the amount of bases in a solution that can be converted to uncharged species by a strong acid.

Definition:

                Alkalinity is the name given to the quantitative capacity of an aqueous solution to neutralize an acid.

Units of alkalinity:

Alkalinity is expressed in units of milligrams per liter (mg/l) of CaCO3 (calcium carbonate).

Related theory: 

1. Ions causing alkalinity

2. Benefits of alkaline water on health:

3. Principle:

4. The alkalinity test:

Total alkanity:

                       Total alkanity is defined as sum of phenolphthalein alkanity and methyl alkanity. Total alkanity is calculated in following two steps.

Step 1: phenolphthalein alkalinity:

Step 2: methyl orange alkalinity:

Apparatus: 

1. Burette
2. Pipette
3. Titration flask
4. Burette stand 

Reagents:

a.Phenolphthalein
b. Methyl orange
c. H2SO4

Procedure:

1.      50 mL of sample was taken in a titration flask and 1-2 drops of phenolphthalein indicator was added in it.
2. The appearance of pink color indicate OH- ions are present
3. Then this solution was titrated against 0.02 N sulfuric acid, till the solution becomes colorless.
4. The volume of H2SO4 was notes and was labeled as ‘P’ mL.
5.Then methyl orange indicator was added in the same solution. Color change occurs to orange color.
6. The solution was titrated against 0.02 N H2SO4 till red color appear

7. The volume used for this was noted and was labeled as “M ml”.

• 1-2 drops of phenolphthalein indicator
• Pink color Appears (pH>8.3)
• Pink color do not appears
• OH- are present
• OH- are not present
• phenolphthalein alkalinity exists
• phenolphthalein alkalinity do not exists

8. Then by using the following formulas phenolphthalein alkalinity, methyl orange alkalinity and total alkalinity was calculated.

Phenolphthalein alkalinity (mg/L as CaCO3) = 
Methyl orange alkalinity (mg/L as CaCO3) = 
Total alkalinity (mg/L as CaCO3) =

MO gives orange color if pH is 7-8 and gives red if pH <6 and OH- has pH more than 9.

Observations and calculations:

Sample 1 (lab prepared)
Volume of sample = 50 ml

1.7 Phenolphthalein:

H2SO4 Volume 1
0 ml
H2SO4 Volume 2
0 ml
H2SO4 volume 3
0 ml
Mean Volume of H2SO4
0 ml

No OH- ion is present
Phenolphthalein volume = (P mL) 0 mL
Phenolphthalein alkalinity =

1.8 Methyl Orange:

H2SO4 Volume 1
9.7
H2SO4 Volume 2
9.5
H2SO4 volume 3
10.1
Mean Volume of H2SO4

Methyl orange alkalinity (mg/L as CaCO3) =
Methyl orange alkalinity (mg/L as CaCO3) =
Methyl orange alkalinity (mg/L as CaCO3) =
Total alkalinity (mg/L as CaCO3) =
Total alkalinity (mg/L as CaCO3) =

Sample 2 (Lab Prepared)
Volume of sample = 50 mL

1.9 Phenolphthalein:

H2SO4 Volume 1
32 ml
H2SO4 Volume 2
31 ml
H2SO4 volume 3
32.1 ml
Mean Volume of H2SO4

Phenolphthalein alkalinity (mg/L as CaCO3) =
Phenolphthalein alkalinity =

1.10 Methyl Orange:
H2SO4 Volume 1
22.6 ml
H2SO4 Volume 2
22 ml
H2SO4 volume 3
22.9 ml
Mean Volume of H2SO4

Methyl orange alkalinity (mg/L as CaCO3) =
Methyl orange alkalinity (mg/L as CaCO3) =
Total alkalinity (mg/L as CaCO3) =

Environmental significance:

STANDARD FOR DRINKING WATER:

1.Desirable Limit: 200 mg/L
2.Permissible limit in the absence of an alternative source: 600mg/L
3.Beyond this limit taste becomes unpleasant.

Comments and recommendations:
                                                         This was very interesting practical in which we learn about alkanity and its types also we learn about how to calculate the alkanity of given sample.

References:

 Experiment # 4

Title:

Hardness determination of Waste water.

Objective:

  To Measure the Hardness of of given Water sample .

Related theory:  

Hardness:

It is the property of water to precipitate soap.

Hard water:

It is the water that has higher content of dissolved minerals.

They do not produce significant foam with soap.

Example: Ca++, Mg ++

Relationship between Hardness and Alkalanity :

Alkalinity and hardness are related through common ions formed in aquatic systems. Specifically, the counter-ions associated with the bicarbonate and carbonate fraction of alkalinity are the principal ions responsible for hardness (usually Ca⁺⁺ and Mg⁺⁺). As a result, the carbonate fraction of hardness (expressed as CaCO₃ equivalents) is chemically equivalent to the bicarbonates of alkalinity present in water (Burton Jr. and Pitt 2002) in areas where the water interacts with limestone (Timmons et al. 2002). Any hardness greater than the alkalinity represents noncarbonate hardness.

Classification of Hardness:

Temporary Hardness:  We can remove by boiling of water. It is due to CaCO3,  Ca(CHCO3)2 ,MgC03.

Permanent Hardness: Solid particles cannot be removed by boiling of water. It is due to sulphates, salts of calcium and magnesium. We can remove them by chemical process which is called softening and ion exchange process

Classification Based on Metallic ions:

1)      Calcium Hard water: Presence of calcium in any solution is called Calcium hard water.

2)       Magnesium: Presence of magnesium in any solution is called Magnesium hard water.

We never use hard water in industries because boilers of industry can burst. However, Sufficient amount of calcium , magnesium is good for health.

Soft water<75 mg/l of CaCO3

Hard water = 75-150mg/l of CaC03

           Moderate Hard water: 150-300mg/l of CaC03

           Very Hard water>300mg/l of CaC03

   Apparatus:

•     Beaker
•    Volumetric cylinder
•     Buratte
•     Pipette
•    Titration Flask

          Reagents:

           EDTA( Ethylene diamine acetic acid)

           NaoH

           Ammonia buffer

   

             Indicators:

             EBBR

              EBT

    Procedure:

          Total hardness:

1.25mL of sample was taken and 25 mL of distilled water was added in an Erlenmeyer flask.
2. Then1 mL of ammonia buffer solution was taken in the flask.
3. A pinch of EBT solution was added.
4. So violet color will appear
5.The solution was titrated against standard 0.01 N EDTA slowly till the color changes to blue color.
6. The volume of EDTA added was noted and labeled as “A” mL.
7. Same procedure was repeated for blank (50 mL of distilled water).
8. The volume of EDTA added was noted and labeled as “B” mL.
    A-B = C mL
    Total hardness (mg/L as CaCO3) =

  

    Calcium hardness:

 1.25mL of sample was taken and 25 mL of distilled water was added in an Erlenmeyer flask.
 2. Then 2 mL of NaOH solution was added in it.
 3. A pinch of EBBR was added in it till color changes to pink color.
 4. Then it was titrated standard 0.01 N EDTA slowly until the color changes to blue color.
 5. The volume of EDTA added was noted and labeled as “A” mL.
 6. Same procedure for blank was repeated (50 mL of distilled water).
 7. The volume of EDTA added was noted and labeled as “B” mL.
     A-B = D mL
     Calcium hardness (mg/L as CaCO3) =
  

Magnesium hardness:

Magnesium hardness = Total hardness – Calcium hardness

Observations and calculations:  

       Total hardness :

It is the sum of Calcium Hardness and Magnesium Hardness.

Environmental significance

Calcium and magnesium are needed to support calcification of larval skeletal structures and to support newly fertilized freshwater fish eggs (Timmons et al. 2002). Additionally, hardness has been associated with mitigation of the toxicity of some metals to gill-breathing organisms. In fact, the Florida Department of Environmental Protection (FDEP) state water quality criteria for copper in Class I and III freshwater* is based on water hardness using the following relationship

The mitigating effects are likely due to the individual polyvalent cations (e.g., Mg⁺⁺, Ca⁺⁺) causing hardness as opposed to hardness itself (Burton Jr. and Pitt 2002). Some of the mitigating effects may be due to the formation of less bioavailable metallic hydroxides and carbonates by associated increases in alkalinity or due to competition of the polyvalent hardness ions for active sites on/in the organism (antagonistic effects).

Hardness can also affect the utility of water for industrial purposes. Hard water is often the source of scale formed in hot water heaters and industrial systems where water is heated. This scale results from the precipitation of calcium carbonate, which becomes less water soluble as the temperature increases (Snoeyink and Jenkins 1980). In these situations, water is usually softened by precipitating the CaCO₃ or by using ion exchange softening methods.

 Comments and recommendations:

1.      The color change become impractically slow with the decrease in temperature, so conduct titration at or near normal room temperature

2.      Complete the titration within 5 minutes to minimize the precipitation of CaCO3 

3.      Dilute the sample with distilled water to reduce the CaCO3 concentration.

References:

Experiment NO # 5

                                         pH MEASUREMENT

 INTRODUCTION:

Definition:

The concept of pH is unique among the commonly encountered physicochemical quantities listed in the IUPAC Green Book in that, in terms of its definition;

pH = −log aH

It involves a single ion quantity, the activity of the hydrogen ion, which is immeasurable by any thermodynamically valid method and requires a convention for its evaluation.1

pH is a term used to express the intensity of an acid or an alkaline condition of a solution.

Environmental significance:

* Effects on humans:

Exposure to extreme pH values results in irritation to the eyes, skin, and mucous membranes. Eye irritation and exacerbation of skin disorders have been associated with pH values greater than 11. In addition, solutions of pH 10–12.5 have been reported to cause hair fibres to swell. Exposure to low pH values can also result in similar effects. Below pH 4, redness and irritation of the eyes have been reported, the severity of which increases with decreasing pH. In addition, because pH can affect the degree of corrosion of metals as well as disinfection efficiency, it may have an indirect effect on health.

* Water supply:

In water distribution systems pH is a very important consideration to be fulfilled especially in water treatment systems. It is a factor to be considered in coagulation, disinfection, water softening and corrosion control. The following are the guidelines given for these practices;

Sr. No. Process pH guideline

1 Coagulation 6 to 73

2 Disinfection Less than 84

3 Water softening No guideline as such

4 Corrosion control 6.5 to 94

The pH of the water entering the distribution system must be controlled to minimize the corrosion of water mains and pipes in household water systems. Failure to do so can result in the contamination of drinking-water and in adverse effects on its taste, odour, and appearance.

The optimum pH will vary in different supplies according to the composition of the water and the nature of the construction materials used in the distribution system, but is often in the range 6.5–9.5. Extreme pH values can result from accidental spills, treatment breakdowns, and insufficiently cured cement mortar pipe linings.

No health-based guideline value is proposed for pH.3

* Wastewater treatment:

It is a common to use biological and chemical treatment methods to treat industrial or domestic wastewaters. For such treatments it is necessary to know the pH of the influent to see whether the selected treatment mechanism is favourable or not as well as to control pH fluctuations in the waste stream. For biological processes, pH must be controlled within a favourable range in order to ensure the conditions needed to sustain a particular microorganism.

FACTORS AFFECTING THE READINGS:

INSTUMENTATION:

A pH measurement loop is made up of three components, the pH sensor, which includes a measuring electrode, a reference electrode, and a temperature sensor; a preamplifier; and an analyser or transmitter. A pH measurement loop is essentially a battery where the positive terminal is the measuring electrode and the negative terminal is the reference electrode. The measuring electrode, which is sensitive to the hydrogen ion, develops a potential (voltage) directly related to the hydrogen ion concentration of the solution. The reference electrode provides a stable potential against which the measuring electrode can be compared.

Typical pH sensor

When immersed in the solution, the reference electrode potential does not change with the changing hydrogen ion concentration. A solution in the reference electrode also makes contact with the sample solution and the measuring electrode through a junction, completing the circuit. Output of the measuring electrode changes with temperature (even though the process remains at a constant pH), so a temperature sensor is necessary to correct for this change in output. This is done in the analyser or transmitter software.

The pH sensor components are usually combined into one device called a combination pH electrode. The measuring electrode is usually glass and quite fragile. Recent developments have replaced the glass with more durable solid-state sensors. The preamplifier is a signal-conditioning device. It takes the high-impedance pH electrode signal and changes it into allow impedance signal which the analyser or transmitter can accept. The preamplifier also strengthens and stabilizes the signal, making it less susceptible to electrical noise.

The sensor's electrical signal is then displayed. This is commonly done in a 120/240 V ac-powered analyser or in a 24 V dc loop-powered transmitter. Additionally, the analyser or transmitter has a man machine interface for calibrating the sensor and configuring outputs and alarms, if pH control is being done.

A typical pH meter.

A successful pH reading is dependent upon all components of the system being operational. Problems with any one of the three: electrode, meter or buffer will yield poor readings.

Electrodes: A pH electrode consists of two half-cells; an indicating electrode and a reference electrode. Most applications today use a combination electrode with both half cells in one body. Over 90% of pH measurement problems are related to the improper use, storage or selection of electrodes.

Meters: A pH meter is a sophisticated volt meter capable of reading small millivolt changes from the pH electrode system. The meter is seldom the source of problems for pH measurements. Today pH meters have temperature compensation (either automatic or manual) to correct for variations in slope caused by changes in temperature. Microprocessor technology has created many new convenience features for pH measurement; auto-buffer recognition, calculated slope and % efficiency, log tables for concentration of ions and more.

Buffers:

These solutions of known pH value allow the user to adjust the system to read accurate measurements. For best accuracy:

* Standardization should be performed with fresh buffer solutions.

* Buffer used should frame the range of pH for the samples being tested.

* Buffers should be at the same temperature as the samples. (For example: if all your samples are at 50 °C, warm your buffers to 50 °C using a beaker in a warm bath.)

PROCEDURE:

Zero calibration

This calibration is used to offset the asymmetry potential. For calibration procedure, a buffer solution of pH 7 and pH 4 is to be used.

Measuring pH

* Switch on the instrument.

* Calibrate the instrument.

* Take the sample whose pH is to be determined.

* Insert glass probe of the pH meter in the sample and wait for 5-10 minutes. When blinking quotation of the stabilizing on the screen of pH meter stops, note that reading.

* Take the glass electrode probe out from the solution and place it in the buffer solution again before using it for the next sample.

PRECAUTIONS:

REMARKS:

REFERENCES:

OBSERVATIONS:

The following results were obtained:

Sr.No.  Samples  pH    Temperature °C

1

2

3

4

REMARKS:

REFERENCES:

1. MEASUREMENT OF pH. DEFINITION, STANDARDS, AND PROCEDURES (IUPAC Recommendations 2002) Pure Appl. Chem., Vol. 74, No. 11, pp. 2169–2200, 2002.

2. Techniques in Environmental Sciences and Management, Dr Khurshid Ahmed, 2nd edition, page 69.

3. Cogulation : James K Edswald Gary S Kaminiski , A simple method for water plant optimization and operation of coagulation , WQTC conference, American water works association, 2007.

4. pH in Drinking-water Background document for development of WHO Guidelines for Drinking-water Quality, WHO/SDE/WHO/03.04/12, n Guidelines for drinking-water quality, 2nd ed. Vol. 2. Health criteria and other supporting information. World Health Organization, Geneva, 1996.