project report design of bioreactor landfill for allahabad city

Project Report

Design of Bioreactor Landfill for Allahabad City

Submitted in partial fulfilment for the award of B. Tech. Degree Under the supervision of

Dr. Nekram Rawal

Department Of Civil Engineering

Motilal Nehru National Institute of Technology Allahabad

Allahabad

Submitted By:

Avaneesh Kumar Yadav 20101067

Nirbhay Narayan Singh 20106038

Akhilesh Kumar Pal 20101050

CONTENTS

CANDIDATES DECLARATION 1

CERTIFICATE 2

ACKNOWLEDGEMENT 3

CHAPTER

1: Introduction 4

1.1 General 4

1.2 Scope of Present Study 4

1.3 Study Area 5

1.4 Present Management Scenario of MSW at Allahabad city 5

1.5 Objectives 6

2: Literature Review 7

2.1 Bioreactor Landfill 7

2.2 Bioreactor Landfill Types 7

2.2.1 Anaerobic Bioreactor Landfill 7

2.2.2 Aerobic Bioreactor Landfill 7

2.2.3 Hybrid (Aerobic-Anaerobic) Bioreactor Landfill 7

2.3.1 Leachate 8

2.3.2 Leachate Pollution Index 8

2.4 Parameters Testing Methodology 9

2.4.1 Biochemical Oxygen Demand (BOD) 9

2.4.2 Chlorides 14

2.4.3Chemical Oxygen Demand 16

2.4.4 Copper 18

2.4.5 Iron 19

2.4.6 Nitrogen 21

2.4.7 Most Probable Number 24

2.4.8 ph 25

2.4.9 Sulphate 27

2.4.10 Total Dissolved Solid 29

2.4.11 Arsenic 30

2.5 Settlement of MSW 31

2.6 Mechanisms That Cause Large Settlements 31

2.6.1 Mechanical/Primary Compression 31

2.6.2 Biodegradation 32

2.6.3 Physical Creep Compression (Including Ravelling/Void Filling) 32

2.7 Mechanisms That Cause Small Settlements 32

2.7.1 Interaction 32

2.7.2 Consolidation 32

2.8 Methodology for Primary and Mechanical Compression 32

2.9 Leachate Quantity 34

2.10 Gasses in Landfill 35

2.11 Liner System 35

2.11.1 Single Liner System 35

2.11.2 Single Composite Liner System 35

2.11.3 Double Liner System 36

2.12 Design of Landfill Liners 38

2.13 Geo-Membranes 39

2.13.1 Specifications 39

3.14 Daily Cover 39

3.15 Final Cover 39

3.16 Ground Water Monitoring Wells around A Landfill 40

3.17 Surface Water Drainage System 40

3.18 Post Closure Use of Landfills 41

3: Result and Analysis 42

3.1 Census Data for Allahabad City 42

3.2 MSW Data for Allahabad City 42

3.3 LPI Parameters Details 44

3.3.1 BOD 44

3.3.2 Chloride 44

3.3.3 COD 45

3.3.4 Copper 46

3.3.5 Iron 46

3.3.6 Kjeldahl Nitrogen 47

3.3.7 MPN Value 47

3.3.8 ph 48

3.3.9 Sulphate 48

3.3.10 Total Dissolved Solids 49

3.3.11 Arsenic 49

3.4 Calculation of LPI 51

3.5 Computation of Primary and Mechanical Compression 51

3.6 Leachate Volume 55

3.7 Volume Lost Through Evaporation 56

3.8 Gasses Generation in Landfill 59

3.9 Design of Leachate Collection System 60

3.10 Design of Leachate Collection Pond 61

3.11 Leachate Recirculation System 62

3.12 Design of Gas Collection System 62

3.13 Daily Cover 64

3.14 Final Cover 65

3.15 Ground Water Monitoring Wells around A Landfill 65

3.16 Surface Water Drainage System 65

3.17 Calculation of Bioreactor Size 65

3.18 Layout of Landfill Bottom 66

4: Conclusions 67

4.1 Future Scope of the Study 68

Appendix 1 Iron Absorbance Std. Curve

Appendix 2 Sample Collection Date

Appendix 3 MPN Table

Appendix 4 Sub-Index Value Curve

Appendix 5 Typical Value for Geo Membrane

Tables

Table 3.1 Census data for Allahabad City 42

Table 3.2 MSW Data for Allahabad City 43

Table 3.3 LPI Parameters Details 51

Table 3.4 LPI Calculation 51

Table 3.5 Settlement Details 53

Table 3.7 Rainfall Data for Allahabad City 55

Table 3.8 Temperature and Humidity data for Allahabad City 55

Table 3.9 Temperature vs. Saturation Vapour pressure ew 57

Table 3.10 Calculation of Evaporation 58

Table 3.11 Calculation of Leachate Quantity 58

Table 3.12 Composition of elements in waste 59

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CANDIDATES DECLARATION

We hereby submit the project entitled Design of Bioreactor Landfill for

Allahabad City as approved by the project supervisor Dr. Nekram Rawal, Assistant

Professor, Department of Civil Engineering, MNNIT Allahabad. We hereby declared that all

the informations in this project work are correct. We also declare that, to the best of our

knowledge and belief, this work has not been submitted earlier for the award of any other

Degree and Diploma.

(Avaneesh Kumar Yadav) (Nirbhay Narayan Singh) (Akhilesh Kumar Pal)

(20101067) (20106038) (20101050)

Place: MNNIT Allahabad

Date:

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CERTIFICATE

This is to certify that the project entitled Design of Bioreactor Landfill for

Allahabad City submitted by Avaneesh Kumar Yadav , Nirbhay Narayan Singh and

Akhilesh Kumar Pal in partial fulfillment of the requirements for award of the degree of

BACHELOR OF TECHNOLOGY (CIVIL ENGINEERING) to Motilal Nehru National

Institute of Technology Allahabad is the record of students own work and it was carried out

under my supervision.

Date: (Nekram Rawal)

Assistant Professor CED

MNNIT Allahabad

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ACKNOWLEDGEMENT

We would like to express our gratitude to all the people behind the screen who helped us to

transform an idea into a real application. We would like to thank our internal guide Assistant

Prof. Nekram Rawal for his technical guidance, constant encouragement and support in

carrying out our project at college.

We are very thankful to Asst. Prof. Sumedha Chakma for providing valuable suggestion and

helping us to complete this project. We are thankful to Mr. Anil Shrivastav and Ms. Preeti for

providing us raw data of existing landfill. We are thankful to Prof. R. C. Vaishya for helping

us for testing of samples. We are also grateful to Mr. Brij Kishore and Mr. Ashish who helped

us in laboratory to carry out the experiments.

We would like thank all the other staff members, both teaching and non-teaching, who have

extended their timely help and eased our task.

Last but not the least, we are also thankful to our friends and colleagues for their support and

help throughout the project.

The satisfaction and euphoria that accompany the successful completion of the task would be

great but incomplete without the mention of the people who made it possible with their constant

guidance and encouragement crowns all the efforts with success.

Avaneesh Kumar Yadav 20101067

Nirbhay Narayan Singh 20106038

Akhilesh Kumar Pal 20101050

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CHAPTER 1

INTRODUCTION

1.1 General

Looking forward to the future, managing wastes need to be improved for the betterment of

environment and life. Source reduction and recycling efforts with landfill disposal would be

important roles for the integrated waste management strategies for the foreseeable future.

Improper management of MSW causes hazards to inhabitants. Increasing population, rapid

economic growth and rise in living standard accelerates the generation rate of municipal solid

waste (MSW) in Indian cities and so for the Allahabad city. The current total quantity of MSW

generation is 500 ton/day, and the average generation rate of MSW estimated as 0.31

kg/capita/day for Allahabad city. There is urgent need to take proper management of solid

waste at Allahabad city since most of the waste is dump in low lying areas.

Bioreactor landfill is the latest technology for managing the municipal solid waste (MSW). The

MSW are all the wastes arising from human and animal activities, that are normally solid and

that are discarded as useless or unwanted materials. MSW includes all solid wastes generated

in the community except for the industrial and agriculture wastes. Over the past decade, India

has enjoyed tremendous growth in its economy. The quantity of MSW produced depends upon

the living standards of its residents. The degree of commercialization, urbanization, and

industrialization, in fact, has resulted in a vast increase in the amount of refuse generated per

person

1.2 Scope of Present Study

A bioreactor landfill thus proposed in the study so that it will enhance the rate of bio-

degradation of MSW under controlled conditions as compared to a traditional landfill.

Bioreactor Landfill is operated by increasing the moisture content of waste by leachate

recirculation and providing additional moisture (if required) to attain optimal waste moisture

content. Liquid recirculation accelerates the decomposition of MSW by distributing moisture,

nutrients, enzymes, and bacteria throughout the waste mass more homogeneously than natural

infiltration alone. Additionally, landfill capacity can be increased since during degradation of

waste, volume decreases thereby providing additional landfill space in existing landfill sites.

Also, the bioreactor process accelerates gas generation that can offer a revenue stream and

decrease the contaminant concentration in the leachate.

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1.3 Study Area

Allahabad is a major city of east Uttar Pradesh State, situated at 25.25_ North latitude and

81.58_ East longitude. It is about 627 km from Delhi and about 815 km from Calcutta.

Allahabad is an ancient city of India, considered holy because it is built on the confluence

(Sangam) of the rivers Ganga, Yamuna and Saraswati.The city has a population of about

1117094 inhabitants (AMC 2011). Allahabad Municipal Corporation (AMC) is responsible for

the management of the MSW generated in the city.

The cities were divided into the four categories based upon the population of the city (Year

2011). The characteristics of the Cities are defined as:

Very Big City Population more than 20 lacs

Big City Population in between 15 lacs and 20 lacs

Medium City Population in between 10 and 15 lacs

Small City Population less than 10 lacs

From above considerations Allahabad comes under medium city.

1.4 Present Management Scenario of MSW at Allahabad city

Solid waste management is a major concerned for Allahabad city and grave problem where

every nooks and corners have some quantity of municipal solid waste .The city of Allahabad

lacks planned solid waste management system. The building wastes generated by construction

activity containing bricks, cement concrete, stones, tiles, wood, also food and other household

wastes are dumped together on street side and roadside, thereby creating nuisance, pollution

and obstruction to traffic. In Allahabad there is no segregation of waste takes place, also

systematic and scientific system of primary collection of waste does not exist. In the absence

of proper segregation practices at source, rag pickers pick up parts of this waste in soiled and

hazardous conditions. There is no proper landfill site available and waste is dumped in a mixed

form in an unscientific manner on open waste land or low lying areas even near the river Ganga

and Yamuna at six different sites. Illegal dumping of the MSW is also very common in the city.

This results not only causing ground water contamination but also air pollution from the

improper dumping of the solid waste.

Inadequate solid waste management in Allahabad City has resulted in the accumulation of

waste on open lands, in drains and in the residential areas, causing a nuisance and foul-smelling

pools, environmental pollution through leachates from heaps (water and soil pollution) and

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burning of waste (air pollution), clogging of drains. This situation is believed to result in poor

environmental conditions, which in turn present an alarming threat to health. There is thus a

need for improved waste management system of the city. As per data available, every year

Nagar Nigam Allahabad spends on an average 18% of its total budget on solid waste

management. In Allahabad Nagar Nigam the entire operation of solid waste management is

performed in four heads namely, cleaning, collection, transportation and disposal. In the city

cleaning and collection operations are performed by Public Health Department of Nagar

Nigam, while transportation and disposal of solid wastes are being performed by public health

department of Nagar Nigam.

1.5 Objectives

Estimation of future production of MSW in the design period of 30 years.

Testing and analysis of leachate by collecting samples.

Determination of settlement rate of MSW, gas production and leachate production.

Selection of the bioreactor type and size from the existing study.

Design of bioreactor landfill components.

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CHAPTER 2

LITERATURE REVIEW

2.1 Bioreactor Landfill

A bioreactor landfill is typically thought of as sanitary landfill that uses enhanced

microbiological processes to transform and stabilize the readily and moderately decomposable

organic waste constituents in a short period of time (typically 5 to 10 years) in comparison to

a conventional landfill (typically 30 to 50 years or more). According to the Solid Waste

Association of North America (SWANA), a bioreactor landfill is a controlled landfill or landfill

cell where liquid and gas conditions are actively managed in order to accelerate or enhance bio

stabilization of the waste. The bioreactor landfill significantly increases the extent of organic

waste decomposition, conversion rates, and process effectiveness over what would otherwise

occur with the landfill.

2.2 Bioreactor Landfill Types

2.2.1 Anaerobic Bioreactor Landfill : In an anaerobic bioreactor landfill, moisture is added to

the waste mass in the form of recirculated leachate and other sources to obtain optimal moisture

levels.Biodegradation occurs in the absence of oxygen (anaerobically) and produces landfill

gas (LFG). Landfill gas, primarily methane, and carbon-dioxide can be captured to minimize

greenhouse gas emissions and for energy generation. The Anaerobic Bioreactor uses anaerobic

bacteria for the degradation of waste. It is generally accepted that to optimize anaerobic

degradation, moisture conditions at or near field capacity, or about 35 to 45 percent moisture

is required.

2.2.2 Aerobic Bioreactor Landfill : In an aerobic bioreactor landfill, leachate is removed from

the bottom layer, piped to liquids storage tanks, and recirculated into the landfill in a controlled

manner. Air is injected into the waste mass, using vertical or horizontal wells, to promote

aerobic activity and accelerate waste stabilization. The aerobic bioreactor uses aerobic bacteria

for degradation. In landfills, aerobic activity is promoted through injection of air into the waste

mass. The aerobic process does not generate methane and typically requires less than two years

for full degradation.

2.2.3 Hybrid (Aerobic -Anaerobic) Bioreactor Landfill : The hybrid bioreactor landfill

accelerates waste degradation by employing sequential aerobic-anaerobic treatment to rapidly

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degrade organics in the upper sections of the landfill and collect gas from lower sections.

Operation as a hybrid results in the earlier onset of methanogens compared to aerobic landfills.

2.3.1 Leachate

Leachate is any liquid that in passing through matter, extracts solutes, suspended solids or any

other component of the material through which it has passed. Leachate from a landfill varies

widely in composition depending on the age of the landfill and the type of waste that it contains.

It can usually contain both dissolved and suspended material. The generation of leachate is

caused principally by precipitation percolating through waste deposited in a landfill. Once in

contact with decomposing solid waste, the percolating water becomes contaminated and if it

then flows out of the waste material it is termed leachate.

2.3.2 Leachate Pollution Index

A technique to quantify the leachate pollution potential of solid waste landfills on a

comparative scale using an index known as the leachate pollution index (LPI) developed. The

LPI is a quantitative tool by which the leachate pollution data of the landfill sites can be

reported uniformly. It is an increasing scale index. The formulation process involved selecting

variables, deriving weights for the selected pollutant variables, formulating their sub-indices

curves and finally representing the pollutant variables to arrive at LPI.

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2.4 PARAMETERS TESTING METHODOLOGY

2.4.1 BIOCHEMICAL OXYGEN DEMAND (BOD)

The biochemical oxygen demand determination is a chemical procedure for determining

the amount of dissolved oxygen needed by aerobic organisms in a water body to break the

organic materials present in the given water sample at certain temperature over a

specific period of time. BOD of water or polluted water is the amount of oxygen

required for the biological decomposition of dissolved organic matter to occur under

standard condition at a standardized time and temperature. Usually, the time is taken as 5

days and the temperature is 20C.The test measures the molecular oxygen utilized during a

specified incubation period for the biochemical degradation of organic material

(carbonaceous demand) and the oxygen used to oxidize inorganic material such as

sulfides and ferrous ion. It also may measure the amount of oxygen used to oxidize

reduced forms of nitrogen (nitrogenous demand).

Apparatus Required

BOD Incubator

Burette & Burette stand

300 mL glass stopper BOD bottles

500 mL conical flask

Pipettes with elongated tips

Pipette bulb

250 mL graduated cylinders

Wash bottle

Chemicals Required

Calcium Chloride

Magnesium Sulphate

Ferric Chloride

Di Potassium Hydrogen Phosphate

Potassium Di Hydrogen Phosphate

Di sodium hydrogen phosphate

Ammonium Chloride

Manganous sulphate

Potassium hydroxide

Potassium iodide

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Sodium azide

Concentrated sulfuric acid

Starch indicator

Sodium thiosulphate

Distilled or deionized

Procedure

For testing the given sample, first the reagents are required to be prepared.

Preparation of Reagent

Manganous Sulphate Solution

Dissolve Manganese Sulphate

480g of (or)

400g of (or)

In freshly boiled and cooled distilled water, filter the solution and make up to 1000

mL (One litre). In this experiment, we are using Manganese sulphate Mono

hydrate.

Take 364g of and transfer it to the beaker. To dissolve the content,

place it in the magnetic stirrer

Note: The solution should not give blue color by addition of acidified potassium

iodide solution and starch.

Alkaline Iodide Sodium Azide Solution

To prepare this reagent we are going to mix three different chemicals

Dissolve either

500 g of Sodium Hydroxide (or)

700 g of Potassium Hydroxide

135 g of Sodium Iodide (or)

150 g of Potassium Iodide

To prepare this reagent, take 700 g of potassium hydroxide and add 150 g of

potassium iodide and dissolve it in freshly boiled and cooled water, and make up to

1000 mL (One litre).

Dissolve 10 g of Sodium Azide in 40 mL of distilled water and add this

with constant stirring to the cool alkaline iodide solution prepared.

Sodium Thiosulphate stock solution Weigh approximately 25 g of sodium

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thiosulphate and dissolve it in boiled distilled water and make up to

1000 mL. Add 1 g of sodium hydroxide to preserve it.

Starch Indicator

Weigh approximately 2 g of starch and dissolve in 100 mL of hot distilled water. In

case if you are going to preserve the starch indicator add 0.2 g of salicylic acid as

preservative.

Sulphuric Acid

Calcium Chloride solution

Weigh accurately 27.5 g of anhydrous calcium chloride and dissolve it in distilled

water.

Take 100 mL standard measuring flask and place a funnel over it.

Transfer it to the 100 mL standard flask and make up to 100 mL using distilled water.

Magnesium Sulphate solution

Weigh accurately 22.5 g of magnesium sulphate and dissolve it in distilled water. Take

100 mL standard measuring flask and place a funnel over it.


Ferric Chloride solution

Weigh accurately 0.15 g ferric chloride and dissolve it in distilled water. Take

100 mL standard measuring flask and place a funnel over it.


Phosphate buffer solution

Weigh accurately 8.5g of Potassium Di Hydrogen Phosphate (KH2PO4) and dissolve

it in distilled water.

Then add exactly 21.75 g of Di Potassium Hydrogen Phosphate (K2HPO4) and

dissolve it. To the same beaker 33.4 g of Di sodium hydrogen phosphate ( Na2HPO4

7H2O), is weighed and added.

Finally to the beaker containing all the salts, add accurately 1.7 g of Ammonium

Chloride (NH4Cl) and dissolve it.



The pH should be 7.2 without further adjustment.

Dilution Water

High quality organic free water must be used for dilution purposes.The required volume

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of water (five liters of organic free distilled water) is aerated with a supply of clean

compressed air for at least 12 hours. Allow it to stabilize by incubating it at 20C for at

least 4 hours.

Add 5mL calcium chloride solution

Add 5mL magnesium sulphate solution

Add 5mL ferric chloride solution and

Add 5mL phosphate buffer solution

This is the standard dilution water. Prepare dilution water 3 to 5 days before

initiating BOD test to ensure that the BOD of the dilution water is less than 0.2

mg/L.

Testing Of Sample

Take four 300 mL glass stoppered BOD bottles (two for the sample and two for

the blank).

Add 10 mL of the sample to each of the two BOD bottles and the fill the

remaining quantity with the dilution water. i.e., we have diluted the sample 30

times.

The remaining two BOD bottles are for blank, to these bottles add dilution water

alone.

After the addition immediately place the glass stopper over the BOD bottles and

note down the numbers of the bottle for identification.

Now preserve one blank solution bottle and one sample solution bottle in a BOD

incubator at 20C for five days.

The other two bottles (one blank and one sample) needs to be analysed

immediately.

Avoid any kind of bubbling and trapping of air bubbles. Remember no bubbles!

Add 2mL of manganese sulfate to the BOD bottle by inserting the calibrated

pipette just below the surface of the liquid.

Add 2 mL of alkali-iodide-azide reagent in the same manner.

(The pipette should be dipped inside the sample while adding the above two

reagents. If the reagent is added above the sample surface, you will introduce

oxygen into the sample.)

Allow it to settle for sufficient time in order to react completely with oxygen.

When this floc has settled to the bottom, shake the contents thoroughly by

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turning it upside down.

Add 2 mL of concentrated sulfuric acid via a pipette held just above the surface

of the sample.

Carefully stopper and invert several times to dissolve the floc.Titration needs to be

started immediately after the transfer of the contents to Erlenmeyer flask.

Rinse the burette with sodium thiosulphate and then fill it with sodium

thiosulphate. Fix the burette to the stand.

Measure out 203 mL of the solution from the bottle and transfer to an Erlenmeyer

flask.

Titrate the solution with standard sodium thiosulphate solution until the yellow

color of liberated Iodine is almost faded out. (Pale yellow color)

Add 1 mL of starch solution. and continue the titration until the blue color

disappears to colourless.

Note down the volume of sodium thiosulphate solution added , which gives the

D.O. in mg/L. Repeat the titration for concordant values.

After five days, take out the bottles from the BOD incubator and analyse the

sample and the blank for DO.

Add 2mL of manganese sulfate to the BOD bottle by inserting the calibrated

pipette just below the surface of the liquid.

Add 2 mL of alkali-iodide-azide reagent in the same manner.

If oxygen is present, a brownish-orange cloud of precipitate or floc will appear.

Allow it to settle for sufficient time in order to react completely with oxygen.

When this floc has settled to the bottom, shake the contents thoroughly by

turning it upside down.

Add 2 mL of concentrated sulfuric acid via a pipette held just above the surface

of the sample.

Carefully stopper and invert several times to dissolve the floc.

Titration needs to be started immediately after the transfer of the contents to

Erlenmeyer flask.

Rinse the burette with sodium thiosulphate and then fill it with sodium

thiosulphate. Fix the burette to the stand.

Measure out 203 mL of the solution from the bottle and transfer to an Erlenmeyer

flask.Titrate the solution with standard sodium thiosulphate solution until the

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yellow color of liberated Iodine is almost faded out. (Pale yellow color)

Add 1 mL of starch solution and continue the titration until the blue color

disappears to colourless.

Note down the volume of sodium thiosulphate solution added, which gives the

D.O. in mg/L. Repeat the titration for concordant values.

2.4.2 CHLORIDES

Chlorides are widely distributed as salts of calcium, sodium and potassium in water

and wastewater. In potable water, the salty taste produced by chloride concentrations is

variable and dependent on the chemical composition of water. The major taste producing

salts in water are sodium chloride and calcium chloride. The salty taste is due to

chloride anions and associated cations in water. In some water which is having only 250 mg

/L of chloride may have a detectable salty taste if the cat-ion present in the water is

sodium. On the other hand, a typical salty taste may be absent even if the water is

having very high chloride concentration for example 1000 mg /L.

Apparatus Required

Burette with Burette stand and porcelain tile

Pipettes with elongated tips

Conical flask (Erlenmeyer Flask)

Standard flask

Beaker

Wash bottle

Chemicals Required

Silver nitrate

Phenolphthalein Indicator

Sodium chloride

Potassium chromate

Procedure

Preparation of Reagents

Standard Sodium Chloride Solution

Switch on the Electronic balance, keep the weighing pan, and set the reading

to zero.

Weigh 1.648g of Sodium chloride

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Transfer the contents to the beaker containing distilled water. Using glass

rod, dissolve the contents thoroughly.

Transfer the contents in the beaker to a 100 mL standard flask; fill

distilled water up to 100 mL mark.

Transfer it to 100mL standard flask using funnel

Standard Silver Nitrate (0.0282 N)

Weigh 4.791g of Silver nitrate and transfer it to the beaker with distilled water.

Transfer the contents in the beaker to a 100 mL standard flask, fill

distilled water up to 100 mL mark.Standardize it against 0.0282 N NaCl

solution. Store it in an amber bottle

Potassium Chromate Indicator

Weigh 25 g of Potassium Chromate. Transfer it to the beaker contains

distilled water. Add few drops of Silver Nitrate solution until slight red

precipitate is formed.

Allow it to stand for 12 hours. After 12 hours filter the solution using filter

paper and dilute the filtrate to 1000 mL using distilled water.

Testing Of Water Sample

Before starting the titration rinse the burette with silver nitrate solution. Fill

the burette with silver nitrate solution of 0.0282 N. Adjust to zero and fix the

burette in stand.

Take 20 mL of the sample in a clean 250mL conical flask

Add 1 mL of Potassium Chromate indicator to get light yellow color

Titrate the sample against silver nitrate solution until the color changes from

yellow to brick red. i.e., the end point.

Note the volume of Silver nitrate added.

Repeat the procedure for concordant values.

Blank Titration

Take 20 mL of the distilled water in a clean 250mL conical flask

Add 1 mL of Potassium Chromate indicator to get light yellow color

Titrate the sample against silver nitrate solution until the color changes from

yellow to brick red. i.e., the end point.

Note the volume of silver nitrate added for distilled water.

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2.4.3 CHEMICAL OXYGEN DEMAND

The chemical oxygen demand (COD) test is commonly used to indirectly measure the

amount of organic compounds in water. Most applications of COD determine the amount

of organic pollutants found in surface water (e.g. lakes and rivers), making COD a useful

measure of water quality. It is expressed in milligrams per liter (mg/L), which indicates

the mass of oxygen consumed per liter of solution. COD is the measurement of the

amount of oxygen in water consumed for chemical oxidation of pollutants. COD

determines the quantity of oxygen required to oxidize the organic matter in water or

waste water sample, under specific conditions of oxidizing agent, temperature, and time.

This method covers the determination of COD in ground and surface waters, domestic

and industrial wastewaters. The applicable range is 3-900 mg/L.

Apparatus Required

COD Digester

Burette & Burette stand

COD Vials with stand

250 mL conical flask (Erlenmeyer Flask)

Pipettes

Pipette bulb

Tissue papers

Wash Bottle

Chemicals Required

Potassium dichromate

Sulfuric acid

Ferrous ammonium sulphate

Silver sulphate

Mercury sulphate

Ferroin indicator

Organic free distilled water

Procedure

For testing the given sample, first the reagents are required to be prepared.

Standard Potassium Dichromate Reagent - Digestion Solution

Weigh accurately 4.913 g of potassium dichromate, previously dried at 103C

for 2 - 4 hours and transfer it to a beaker.

- 17 -

Weigh exactly 33.3g of mercuric sulphate and add to the same beaker. Measure

accurately 167 mL of concentrated sulphuric acid using clean dry measuring

cylinder and transfer it to the beaker. Dissolve the contents and cool to room

temperature. (If not dissolved keep it over night).


Carefully transfer the contents to the 1000 mL standard flask and make up to 1000

mL using distilled water.This is the standard potassium dichromate solution to be

used for digestion.

Sulphuric Acid Reagent - Catalyst Solution

Weigh accurately 5.5g silver sulphate crystals to a dry clean 1000 mL beaker.

To this carefully add about 500 mL of concentrated sulphuric acid, allow to stand

for 24 hr.

Standard Ferrous Ammonium Sulphate solution

Weigh accurately 39.2g of ferrous ammonium sulphate crystals and dissolve it in

distilled water. Take 1000 mL standard measuring flask and place a funnel over it.

Carefully transfer the contents to the 1000 mL standard flask and make up to 1000

mL mark using distilled water.

Testing Of Sample

Take three COD vials with stopper (two for the sample and one for the blank).

Add 2.5 mL of the sample to each of the two COD vials and the remaining COD

vial is for blank; to this COD vial add distilled water.

Add 1.5 mL of potassium dichromate reagent - digestion solution to each of the

three COD vials.

Add 3.5 mL of sulphuric acid reagent - catalyst solution in the same

manner.

CAUTION: COD vials are hot now.

Cap tubes tightly. Switch on the COD Digester and fix the temperature at 150 C

and set the time at 2 hours.

Place the COD vials into a block digester at 150C and heat for two hours.

The digester automatically switches off. Then remove the vials and allow it to

cool to the room temperature.

Fill the burette with the ferrous ammonium sulphate solution, adjust to zero

and fix the burette to the stand.

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Add few drops of ferroin indicator. The solution becomes bluish green in colour.

Titrate it with the ferrous ammonium sulphate taken in the burette.

End point of the titration is the appearance of the reddish brown colour.

Note down the volume of ferrous ammonium sulphate solution added for the

blank (A) is 14.1 mL.

Transfer the contents of the sample vial to conical flask.

Add few drops of ferroin indicator. The solution becomes green in colour.

Titrate it with the ferrous ammonium sulphate taken in the burette.

End point of the titration is the appearance of the reddish brown colour.

Note down the volume of ferrous ammonium sulphate solution added for the

sample.

2.4.4 COPPER

Copper is an essential element, however, this heavy metal is an inhibitor of microbial

activity at relatively low concentrations. The objective of this study was to evaluate the

inhibitory effect of copper (II) towards various microbial trophic groups responsible for the

removal of organic constituents and nutrients in wastewater treatment processes.

Materials

Polyvinyl chloride (PVC) membrane

4, 7-dipheny1-2, 9-dimethy1-1, 10-phenanthroline (bathocuproine)

o- -NPOE).

Colorimeter

Volumetric pipets with bulbs

Test tubes

Test tube rack.

Procedure

Calibrate the colorimeter with standard solution.

A 5 cm3 of aqueous sample containing copper ions was placed in a glass

sample tube (30cm3 volume)

0.5cm3 of 6.510-2mol dm-3 hydroxyl ammonium sulfate, 0.13mol dm-

3 potassium chloride and acetic acid-sodium acetate buffer (pH 5.9) was added.

A sheet of PVC membrane consisting of 0.7wt% bathocuproine and 65.0wt%

- 19 -

-NPOE was put into the solution

Solution was stirred with a magnetic stirrer for a definite time at 60C.

The membrane removed from the solution was rinsed with small amount of

water, and wiped to remove the water droplets.

The absorbance of the colored membrane was measured at 480nm by

spectrophotometer.

The copper ion concentration in the sample solution was determined using a

calibration curve.

2.4.5 IRON

Any solution which is colored or can be made colored by adding a complexing agent can

be analyzed using a visible spectrophotometer, such as the Spec 20. Solutions

containing iron ions are colorless, but upon addition of ortho-phenanthroline, the iron

(II) ions in the sample react immediately to produce a complex ion, which is orange in

color. The more iron (II) ions in a sample will result in a deeper orange color while less

iron (II) ions result in a fainter orange color. This follows the Beer-Lambert Law of

spectroscopy. From data obtained from a series of iron (II) standards, it is possible to be

able to determine the amount of iron in an unknown sample.

Equipment

Spectrophotometer

Cuvettes and rack

Procedure

Part I: Preparation of standards

Dissolve 0.7022 grams of ferrous ammonium sulfate, hexa hydrate into deionized

water. Dilute to 1.00 L. This solution is 100 mg/L of Fe2+ (same as 100 ppm).

Prepare standard solutions of the following concentrations: 0.0, 0.2, 0.6, 1.2, and

1.6 ppm. Use a pipet to transfer 0.0, 0.2, 0.6, 1.2, and 1.6 mLs of the 100 ppm

stock solution into five separate 100 mL volumetric flasks. To each of the flasks,

add 5 mL of a 0.25% ortho-phenanthroline solution with a graduated cylinder.

Carefully dilute to the 100 mL mark by adding deionized water.

Clean a set of six cuvettes and dry the outside. Label the cuvettes: 0 ppm, 0.2

ppm, 0.6 ppm, 1.2 ppm, 1.6 ppm.

- 20 -

Rinse each cuvette with a SMALL amount of the appropriate solution and fill to

about the half-way point.

Part II: Forming the standard curve.

Turn the spectrophotometer on and allow it to warm up for 20 minutes.

Adjust the wavelength to 510 nm.

With the sample compartment empty and the lid closed, set the instrument to 0%T

using the Zero Control Knob. (left front)

Using a Kimwipe, wipe any finger prints from the cuvette containing the Blank

(0ppm) and place this cuvette into the sample compartment being sure to align the

index marks. Close the cover.

Set the instrument to 100%Transmittance using the 100%T/0A knob (right front).

Press the MODE button one time to change the mode from transmittance to

absorbance.

Record the absorbance of the 0 ppm solution (it should be 0.000 A).

Insert each of the cuvettes containing standards into the sample holder, reading the

absorbance values for each one. Record the values in your data table.

Construct a graph of solution concentration (x-axis) vs. absorbance (y-axis).

.(See

Apendix 1)

Part III: Determination of unknown sample.

Obtain an unknown sample from the instructor or prepare your own unknown

sample using a collected water sample.

If using a collected water sample, add 5 mL of the 0.25% ortho-phenanthroline

solution to a 100 mL volumetric flask. Dilute to the line with the collected water.

If using a collected water sample, use collected water without the 0.25% ortho-

phenanthroline solution as the blank. Re-zero the spectrophotometer with this

new blank.

Obtain an absorbance reading for the unknown sample.

- 21 -

From the standard curve, determine the concentration of iron in this unknown

sample.

2.4.6 NITROGEN

Nitrogen compounds are of interest to wastewater treatment plant operators

because of the importance of nitrogen in the life cycles of plants and animals.

Nitrogen is a nutrient and occurs in many forms including ammonia, organic,

nitrate and nitrite each of which may be tested for in a variety of ways. Raw

wastewater nitrogen is normally present in the organic nitrogen and ammonia

forms, with small quantities of the nitrite and nitrate forms. Depending on the

amount of nitrification which occurs within the plant, the effluent may contain

either ammonia or nitrate nitrogen. Under normal circumstances, the nitrite form

of nitrogen will not be present in large quantities due to its rapid oxidation or

conversion to nitrate.

Total Kjeldahl Nitrogen

Total Kjeldahl Nitrogen (TKN) is an analysis to determine both the organic

nitrogen and the ammonia nitrogen.The analysis involves a preliminary digestion

to convert the organic nitrogen to ammonia, then distillation of the total ammonia

into an acid absorbing solution and determination of the ammonia by an

appropriate method.

Equipment

Kjeldahl digestion apparatus

Heating unit capable of heating a 250 mL sample from 25C to boiling within 5

minutes

Fume hood or exhaust fume ejector

Equipment for distillation and measurement of ammonia nitrogen

REAGENTS

Kjeldahl digestion reagent consisting of:

Concentrated Sulfuric acid

Potassium Sulfate

Mercuric Oxide

Phenolphthalein indicator

Sodium hydroxide - Sodium thiosulfate reagent

- 22 -

Borate buffer solution

Sodium hydroxide 6 N

Kjeldahl Digestion Procedure

Select an appropriate volume of sample to be placed in the 500 to 800 mL Kjeldahl

digestion flask.

Expected TKN mL of sample

Concentration (mg/L) to use

0to1 500 (use 800 mL flask)

1to10 250

10to20 100

20to50 50

50to 100 25

Dilute if necessary to 300 mL with ammonia free distilled water.

CAREFULLY add 50 mL of digestion reagent. If large amounts of organic matter are

present, an additional 50 mL of reagent must be added per gram of organic matter.

(This may be estimated from volatile solids information).

Mix thoroughly. (Incomplete mixing can cause bumping during the digestion and

may result in glassware breaking or loss of sample).

Add several glass beads of boiling chips to the flask.

Place flask on digestion apparatus and heat to boiling and continue boiling until you

see the formation of dense white fumes (SO2).

Continue to digest the sample for 30 minutes more. As the digestion continues,

colored or turbid samples will turn clear or straw colored.

- 23 -

Cool the flask and dilute the sample with 300 mL of ammonia free distilled water.

Mix.

Add 0.5 mL phenolphthalein indicator.

Tilt the digestion flask and CAREFULLY add a sufficient amount of sodium

hydroxide - thiosulfate reagent to form an alkaline layer (pink zone) in the bottom of

the flask. Usually 50 mL of reagent is needed for every 50 mL of digestion reagent

used.

Connect the flask to the distillation apparatus, mix thoroughly and distill 200 mL of

distillate into a boric acid absorbing solution.

Pipette 50 mL of distillate or a suitable aliquot diluted to 50 mL with ammonia free

distilled water into a 125 mL Erlenmeyer flask.

Neutralize the boric acid absorbing solution by:

Adding 2 mL Nessler reagent.

Adding Sodium hydroxide to pH near 7 followed by the addition of 1 mL of Nessler reagent

Cap the Erlenmeyer flask with a clean rubber stopper and mix thoroughly.

Allow 10 minutes for color development. (Sample, blank, and standards must be

maintained at the same temperature and color development time.)

NOTE: If ammonia nitrogen is extremely low, allow 30 minute development.

Measure percent transmittance of the sample using a distilled water blank as reference

(%T = 100) at the selected wavelength. (Since the wavelength used is dependent on

the ammonia concentration, the wavelength must be determined experimentally and

then remain constant for standards and samples.)

- 24 -

Concentration (mg/L) Wavelength (nm)

0.4 to 5.0 mg/L 400 to 425

approaching 10 mg/L 450 to 500

Read the nitrogen concentration in ug from the calibration curve and calculate the

ammonia nitrogen.

2.4.7 MOST PROBABLE NUMBER

Human fecal pathogens vary in kind (viruses, bacteria, protozoa) and in number, it would be

impossible to test each water sample for each pathogen. Instead, it is much easier to test for

the presence of nonpathogenic intestinal organisms such as E. coli. E. coli is a normal

inhabitant of the intestinal tract and is not normally found in fresh water. Therefore, if it is

detected in water, it can be assumed that there has been fecal contamination of the water. The

presence of this organism in a water supply is evidence of recent fecal contamination and is

sufficient to order the water supply closed until tests no longer detect E. coli.

Material

Measuring Flask

Test Tube

Durham Tubes

Autoclave

Incubator

Cotton

Beef Extract

Lactose

Peptone

Procedure

Prepare lactose broth by dissolving 3g. Beef extract, 5g. Lactose, and 5g. Peptone in I

L of distilled water.

Add 1o ml of prepared broth in each of the 9 test tubes. Insert one fermentation tube

- 25 -

in inverted position in each of these tubes. Plug each tube with cotton and sterilize in

auto clave.

Inoculate the water sample 10 ml. each in 3 of the above tubes, 1 ml each in next 3

tubes and 0.1 ml each in remaining 3 tubes.

Incubate these tubes at 35C 0.5C.At the end of 24 hr. take out the tubes from

incubator. Shake each gently and examine for any gas formation

Note the no. of positive tubes. Find out 24 hr. presumptive MPN rom statistical table

given in appendix 3.

2.4.8 pH

Determination of pH is one of the important objectives in biological treatment of the

wastewater. In anaerobic treatment, if the pH goes below 5 due to excess

accumulation of acids, the process is severely affected. Shifting of pH beyond 5 to 10

upsets the aerobic treatment of the wastewater. In these circumstances, the pH is

generally adjusted by addition of suitable acid or alkali to optimize the treatment of the

wastewater. pH value or range is of immense importance for any chemical reaction. A

chemical shall be highly effective at a particular pH. Chemical coagulation,

disinfection, water softening and corrosion control are governed by pH adjustment.

Dewatering of oxidation of cyanides and reduction of hexavalent chromium

into trivalent chromium also need a avorable pH range. It is used in the calculation of

carbonate, bicarbonate, CO2 corrosion, stability index and acid base equilibrium. Lower

value of pH below 4 will produce sour taste and higher value above 8.5 a bitter taste.

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.

Apparatus Required

pH meter

Standard flasks

Magnetic Stirrer

Funnel

Beaker

Wash Bottle

- 26 -

Tissue Paper

Chemicals Required

Buffers Solutions of pH 4.01, 7.0 and 9.2

Potassium Chloride

Distilled Water

Procedure

Calibrating The Instrument

Using the buffer solutions calibrate the instrument.

Step 1

In a 100 mL beaker take pH 9.2 buffer solution and place it in a magnetic

stirrer, insert the teflon coated stirring bar and stir well.

Now place the electrode in the beaker containing the stirred buffer and check

for the reading in the pH meter.

If the instrument is not showing pH value of 9.2, using the calibration

knob adjust the reading to 9.2.

Take the electrode from the buffer, wash it with distilled water and then wipe

gently with soft tissue.

Step 2



Now place the electrode in the beaker containing the stirred buffer and check for

the reading in the pH meter.

If the instrument is not showing pH value of 7.0, using the calibration knob

adjust the reading to 7.0Take the electrode from the buffer, wash it with distilled

water and then wipe gently with soft tissue.

Step 3



Now place the electrode in the beaker containing the stirred buffer and check for

the reading in the pH meter.

If the instrument is not showing pH value of 4.0, using the calibration knob

adjust the reading to 4.0.

- 27 -

Take the electrode from the buffer, wash it with distilled water and then wipe

gently with soft tissue.

Now the instrument is calibrated.

Testing Of Sample

In a clean dry 100 mL beaker take the water sample and place it in a

magnetic stirrer, insert the Teflon coated stirring bar and stir well.

Now place the electrode in the beaker containing the water sample and check

for the reading in the pH meter. Wait until you get a stable reading.

The pH of the given water sample is __

Take the electrode from the water sample, wash it with distilled water and then

wipe gently with soft tissue.

2.4.9 SULPHATE

Sulphates is widely distributed in nature and may be present in natural waters in

concentration ranging from few hundred to several thousand mg/L.Sulphates occur

naturally in numerous minerals, including barite, epsomite and gypsum.These dissolved

minerals contribute to the mineral content of drinking-waters.Acid Mine Drainage (AMD)

may contribute large amounts of sulphates through pyrite oxidation. Sulfate is the second

most abundant anion in seawater. Its high concentration owes to the high to moderate

solubility of the salts that it forms with the major cations in seawater, namely, Na, Mg2+

,

and Ca2+

.

Apparatus Required

UV-Visible Spectrometer

Sample tubes

Standard flask

Beaker

Spatula

Measuring Cylinder

Wash Bottle

Tissue Paper

Chemicals Required

Isopropyl Alcohol

- 28 -

Glycerol

Concentrated Hydrochloric acid

Sodium Chloride

Barium chloride

Sodium sulphate

Distilled water

Procedure

Preparation of Reagents

Conditioning reagent

Measure exactly 25 ml glycerol and pour it to a dry clean beaker.

Then, measure 15 mL of concentrated hydrochloric acid and add it to the same

beaker.

To the same beaker, add exactly 50 mL of 95 % isopropyl alcohol and mix well.

Accurate weigh 37.5 g sodium chloride and dissolve it in distilled water.

Then mix all the contents and make up the final volume to 250 mL using

distilled water.

Standard sulphate solution

Weigh accurately 1.479 g anhydrous sodium sulphate and dissolve it in distilled

water.


Transfer it to the 1000 mL standard flask and make up to 1000 mL using

distilled water.

Preparation of Blank, Standards and sample for Testing

Take six 50 mL glass stoppered standard flask (four for standards, one for the

sample and one for the blank).

Add 10 mL of the standard sulphate solution to the first standard flask, 20 mL to

the second, 30 mL to the third and 40 mL to the fourth.

To the fifth standard flask add 20 mL of the sample water.

The sixth standard flask is for the blank, to this standard flask add distilled water alone. To

measure the sulphate content select the fixed wavelength measurement method. Double

click fixed wavelength measurements, the system information are transferred and then

the following window will appear. Click parameter option and select absorbance, fast

response and enter starting value of the wave length in nanometers. For this experiment

- 29 -

load 420 nm as the starting value. Click and enter the sample number, here it is

100.Then load the number of cycles the analysis has to be made. Enter 1 for this case.

Click ok. The details of the entries will be displayed as shown. Note that the absorbance is

not zero so to reset the reading to zero, take distilled water in the two sample tubes and

place them in the chambers of the spectrometer. Now click the button the

instrument resets and shows 0.0000 as reading.

2.4.10 TOTAL DISSOLVED SOLID

The term total dissolved solids refer to materials that are completely dissolved in water.

These solids are filterable in nature. It is defined as residue upon evaporation of filterable

sample. The term total suspended solids can be referred to materials which are not

dissolved in water and are non-filterable in nature. It is defined as residue upon

evaporation of non-filterable sample on a filter paper.

Apparatus Required

Evaporating Dish

Water Bath

Oven

Desiccators

Analytical Balance

Graduated Cylinders

Dish Tongs

Procedure

To measure total dissolved solids, take a clean porcelain dish which has been washed

and dried in a hot air oven at 180C for one hour.

Now weigh the empty evaporating dish in analytical balance

Mix sample well and pour into a funnel with filter paper. Filter approximately 80

-100 mL of sample.

Using pipette transfer 75mL of unfiltered sample in the porcelain dish.

Switch on the oven and allowed to reach 105C. Check and regulate oven and

furnace temperatures frequently to maintain the desired temperature range.

Place it in the hot air oven and care should be taken to prevent splattering of

sample during evaporation or boiling.

- 30 -

Dry the sample to get constant mass. Drying for long duration usually 1 to 2 hours

is done to eliminate necessity of checking for constant mass.

Cool the container in a desiccator. Desiccators are designed to provide an

environment of standard dryness. This is maintained by the desiccant found

inside. Don't leave the lid off for prolonged periods or the desiccant will soon be

exhausted. Keep desiccator cover greased with the appropriate type of lubricant

in order to seal the desiccator and prevent moisture from entering the desiccator

as the test glassware cools.

We should weigh the dish as soon as it has cooled to avoid absorption of moisture

due to its hygroscopic nature. Samples need to be measured accurately,

weighed carefully, and dried and cooled completely.

Note the weight with residue.

2.4.11 ARSENIC

Chronic arsenic poisoning results from drinking contaminated well water over a long

period of time. Many aquifers contain high concentration of arsenic salts. The World

Health Organization recommends a limit of 0.01 mg/L (10ppb) of arsenic in drinking

water. This recommendation was established based on the limit of detection of available

testing equipment at the time of publication of the WHO water quality guidelines. More

recent findings show that consumption of water with levels as low as 0.00017 mg/L

(0.17ppb) over long periods of time can lead to arsenicosis. From a 1988 study in China,

the US protection agency quantified the lifetime exposure of arsenic in drinking water at

concentrations of 0.0017 mg/L, 0.00017 mg/L, and 0.000017 mg/L are associated with a

lifetime skin cancer risk of 1 in 10,000, 1 in 100,000, and 1 in 1,000,000 respectively.

The World Health Organization asserts that a level of 0.01 mg/L poses a risk of 6 in

10000 chance of lifetime skin cancer risk and contends that this level of risk is

acceptable.

Apparatus

As-1 Reagent (11 ml)

As-2 Reagent (145 grams)

Test Strips (100)

Reaction Bottles

Measuring Spoons

- 31 -

Color Matching Card

Carrying Case

Procedure

Take 25 ml sample in the bottle given with the kit.

Add Arsenic Reagent 1 (one Pouch) & 2 spoons of powdered reagent.

Shake the mixture for 1 minute, now add one pouch of Arsenic Reagent 2 and

put the bottle's cap fitted with a strip having mercuric bromide indicator at its

tip immediately.

Strip should neither touch the bottle nor the solution.

Shake the bottle gently & put for 15 minutes for comletion of the reaction.

Now remove the strip and match its colour with the scale given with the kit.

Note down the corresponding reading.

2.5 Settlement of MSW

MSW settles under its own weight and as external loads are placed on the landfill. External

loads include daily soil cover, additional waste layers, final cover, and facilities such as

buildings and roads. MSW settlement is mainly attributed to-

(1) physical and mechanical processes that include the reorientation of particles, movement of the

fine materials into larger voids, and collapse of void spaces;

(2) chemical processes that include corrosion, combustion and oxidation;

(3) dissolution processes that consist of dissolving soluble substances by percolating liquids and

then forming leachate; and

(4) Biological decomposition of organics with time depending on humidity and the amount of

organics present in the waste.

2.6 MECHANISMS THAT CAUSE LARGE SETTLEMENTS

2.6.1 Mechanical/Primary Compression Mechanical/primary compression is due to

distortion,

Bending, crushing and reorientation of materials caused by the weight of overburden and

compaction. This settlement occurs rapidly and is typically complete within approximately one

month from the time the filling is complete. At the Landfill, mechanical and primary

compression due to fills was estimated to range from 10 to 20 percent of new fill thicknesses

based on empirical data collected during a soil fill placement. The actual primary compression

depends on fill geometry, density of landfill and overburden, and landfill composition.

- 32 -

2.6.2 Biodegradation: Aerobic and anaerobic decomposition of organic material by bacteria

is theprocess known as biodegradation. For anaerobic decomposition of cellulose, which is the

primarymechanism of biodegradation, bacteria convert carbon-based solid material and water

intoprimarily carbon dioxide and methane. This conversion results in a loss of solid mass. Most

settlement after landfill construction is due to this mechanism.

2.6.3 Physical Creep Compression (Including Ravelling/Void Filling): This mechanism is

caused by:

(1) Erosion and sifting of finer materials into voids between larger particles;

(2) Material moving into voids as a result of biodegradation; and

(3) Continued elastic compression.

Void filling is partly related to a weakening of the support of the solids due to such things as

Biodegradation and corrosion, which causes a reduction of the rigidity of landfill materials

This form of settlement equals about2 percent of the fill height per log cycle of time. For the

landfill, physical creep compression was estimated to contribute from 0 to 7 feet of additional

settlement over the next 90 years.

2.7 MECHANISMS THAT CAUSE SMALL SETTLEMENTS

2.7.1 Interaction: Examples of interaction include methane supporting combustion,

spontaneous

Combustion and organic acids causing corrosion. This mechanism is closelyassociated with

the occurrence of the other mechanisms. By itself, interaction is not expected torepresent a

significant amount of settlement over a large areal extent. It could result in largelocalized

settlements; although with a properly maintained and operated LFG collection systemand cover

in place, the source of oxygen to support combustion will be significantly reduced.

2.7.2 Consolidation: Consolidation settlement is caused by excess water squeezing from pore

spaces in low permeable soil formations. If landfill is not saturated then settlement due to

consolidation is not expected.

2.8 Methodology for Primary and Mechanical Compression

The waste mass consists of layers of refuse of finite thickness. Addition of a new waste layer

causes settlement, attributable theweight of the overlaying layers, and stress increases

- 33 -

instantaneouslybecause of construction of a new layer.The strain [(t)] resulting from an

instantaneous response to surcharge loading can be expressed by

(t) = C log(( 0 + )/ 0 ) (1)

where C = compression ratio (coefficient of compressibility);

0 = initial vertical stress; and

heightsHi is computed by

(2)

Thus, the strain in each lift of the multilayer fill can be expressed bythe equation

(3)

where C = coefficient of compressibility;

Hi = initial thickness ofthe compacted lift (assumed initially same for all the lifts);

mechanical strain, respectively.

The primary compression (S(t)pi) can be obtained by

S(t)pi = Hj pi(t) (4)

Similarly, the mechanical compression (S(t)mi ) attributable to creep, is obtained by

S(t)m = H mi(t) (5)

Eqs. (4) and (5) give the temporal change of primary andmechanical compressions attributable

to overlaying layers. Theseequations can be used to compute primary and mechanical

settlementwhile assuming constant density, or spatial and temporal

variation of density.

Model Parameters:

Coefficient of Compressibilityand DensityIn Eq. 3, the coefficient of compressibility (C) is

used for bothprimary and mechanical strain. The value C is found from the relationship

- 34 -

(6)

where C = compressive index; eo = initial void ratio of the solidwaste; and t = time after landfill

closure (years).The compressive index C is primarily dependent on the voidratio and is

obtained from the slope of the void ratio versus log-timecurve. The following range is provided

for estimating the compressiveindex:

C = (0.15 to 0.55)eo for primary compression;

(0.03 to 0.09)eo for secondary compression

The value of C is different for primary and mechanical compression. The coefficient of

compressibility for primarycompression lies in the range 0.10.5, whereas secondary

compressionlies in the range 0.0120.08.

The variation of refuse density with depth (z) is computed by the method of Manna et al. using

Eq. (7)

Pz = Pm+(Pm P0) ((z/z + )) (7)

where Po = starting value of the density;

Pm= maximum density value corresponding to infinite load; and

Once the density is known by Eq. (7), the unit weight of thesolid waste is calculated by

multiplying the acceleration due togravity (g) with density. The temporal variation of the unit

weightis then obtained by

(8)

t) = required unit weight at time t (days) and

i = initial unit weight of the refuse.

Density varies from 600694 kg/m3 during activefilling, whereas the maximum density

observed is in the range11861653 kg/m3.

2.9 Leachate Quantity

The quantity of leachate generated in a landfill is strongly dependent on the quantity of

infiltrating water. This, in turn, is dependent on weather and operational practices. The amount

of rain falling on a landfill to a large extent controls the leachate quality generated. Precipitation

- 35 -

phases of a landfill under operation during the monsoon season. The leachate quantity from

those portions of a landfill which have received a final cover is minimal.

The leachate generation during the operational phase from an active area of a landfill may be

estimated in a simplified manner as follows:

Leachate volume = (volume of precipitation) + (volume of pore squeeze liquid)

(Volume lost through evaporation) (volume of water absorbed by the waste).

2.10 Gases in Landfill

Gases found in landfills include air, ammonia, carbon dioxide, carbon monoxide, hydrogen,

hydrogen sulphide, methane, nitrogen, and oxygen. Carbon dioxide and methane are the

principal gasses produced from the anaerobic decomposition of the organic solid waste.

2.11 Liner System

Liner systems comprise of a combination of leachate drainage and collection layer(s) and

barrier layer(s). A competent liner system should have low permeability, should be robust and

durable and should be resistant to chemical attack, puncture and rupture. A liner system may

comprise of a combination of barrier materials such as natural clays, amended soils and flexible

geo-membranes.

Three types of liner systems are usually adopted and these are described hereafter:

2.11.1 Single Liner System: Such a system comprises of a single primary barrier overlain by

a leachate collection system with an appropriate separation/protection layer. A system of this

type is used for a low vulnerability landfill. It is suitable for LPI less than 7.

2.11.2 Single Composite Liner System: A composite liner comprises of two barriers, made

of different materials, placed in intimate contact with each other to provide a beneficial

- 36 -

combined effect of both the barriers. Usually a flexible geo-membrane is placed over a clay or

amended soil barrier. A leachate collection system is placed over the composite barrier. Single

composite liner system are often the minimum specified liner system for non-hazardous wastes

such as MSW. For LPI between 7and 25 it is best suited liner type.

2.11.3 Double Liner System: In a double liner system a single liner system is placed twice,

one beneath the other. The top barrier (called the primary barrier) is overlaid by a leachate

collection system. Beneath the primary barrier, another leachate collection system (often called

the leak detection layer) is placed followed by a second barrier (the secondary barrier). This

type of system offers double safety and is often used beneath industrial waste landfills. It allows

the monitoring of any seepage which may escape the primary barrier layer. For LPI greater

than 25, it is taken into consideration.

Since LPI for the MSW waste for Allahabad is 19.86.Hence we will go for composite type

liner. The advantages of a composite liner system are immense and often not widely

recognised. The way that a composite liner works is sketched in figure and iscontrasted with

individual geo-membranes and soil liners. To achieve goodcomposite action, the geo-

membrane must be placed against the clay with good hydraulic contact. To achieve intimate

contact, the surface of a compacted soilliner on which the geo-membrane is placed should be

smooth-rolled with a steel drum roller. All oversize stones in the soils should be removed prior

- 37 -

to rolling.Also, the geo-membrane should be placed and backfilled in a way that minimizes

wrinkles.

On a basis of review of liner systems adopted in different countries , it is recommended that

for all MSW landfills the following single composite liner system be adopted (waste

downwards) as the minimum requirement :

(a) A leachate drainage layer 30 cm thick made of granular soil having permeability (K) greater

than 10-2 cm/sec.

(b) A protection layer (of silty soil) 30 cm thick.

(c) A geo-membrane of thickness 2.0 mm.

(d) A compacted clay barrier or amended soil barrier of 1 m thickness having permeability (K)

of less than 10-7cm/sec.

- 38 -

2.12 DESIGN OF LANDFILL LINERS

The selection of material to be used a soil barrier layer will usually be governed by the

availability of materials, either at site or locally in nearby areas. The hierarchy of options will

usually be as follows:

(a) Natural clay will generally be used as a mineral component of a liner system where suitable

clay is available on site or nearby.

(b) If clay is not available, but there are deposits of silts (or sands), then formation of good

quality bentonite enhanced soil/amended soil, may be economical.

Compacted Clays: Wherever suitable low permeability natural clay materials are available,

they provide the most economical lining material and are commonly used. The basic

requirements of a compacted clay liner is that it should have permeability below a pre-specified

limit (10-7cm/sec) and that this should be maintained during the design life. Natural clay

available in-situ is usually excavated and re-compacted in an engineered manner. If clay is

brought from nearby areas, it is spread in thin layers and compacted over the existing soil. The

quality of the in-situ clay may be good enough to preclude the requirement of acompacted clay

liner, only if it has no desiccation cracks and is homogeneous aswell as uniformly dense in

nature.

Amended Soils: When low-permeability clay is not available locally, in-situ soilsmay be

mixed with medium to high plasticity imported clay, or commercial clayssuch as bentonite, to

achieve the required low hydraulic conductivity. Soil bentonite admixtures are commonly used

as low permeability amended soil liners.Generally, well-graded soils require 5 to 10 percent by

dry weight of bentonite,while uniformlygraded soils (such as fine sand), may typically require

10 to 15percent bentonite. The most commonly used bentonite admixture is sodium bentonite.

Calcium bentonite may also be used, but more bentonite may be neededto achieve the required

permeability, because it is more permeable than sodiumbentonite.

A competent barrier made of compacted soils - clays or amended soils is normally expected

to fulfil the following requirements:

(a) Hydraulic conductivity of 10-7 cm/sec or less;

(b) Thickness of 100 cm or more;

(c) Absence of shrinkage cracks due to desiccation;

(d) Absence of clods in the compacted clay layer;

(e) Adequate strength for stability of liner under compressive loads as well as alongside slopes;

and

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(f) Minimal influence of leachate on hydraulic conductivity.

Clays of high plasticity with very low values of permeability (usually well below the prescribed

limit), exhibit extensive shrinkage on drying, as well as tend to form large clods during

compaction in the relatively dry state. Their permeability can also increase on ingress of certain

organic leachates. Well compacted inorganic clays of medium plasticity, either natural or

amended, appear to be most suitable for liner construction.

2.13 Geo-membranes

A High Density Poly ethylene (HDPE) geo-membrane of minimum thickness of 1.5 mm is to

be laid over the compacted clay/amended soil with no gaps along the surface of contact.

2.13.1 Specifications

The geo-membrane is normally expected to meet the following requirements:

(a) It should be impervious.

(b) It should have adequate strength to withstand subgrade deformations and construction

loads.

(c) It should have adequate durability and longevity to withstand environmental loads.

(d) The joints/seams must perform as well as the original material.

3.14 Daily Cover

The advantages of using daily cover are primarily in preventing windblown litter and odors,

deterrence to scavengers, birds and vermin and in improving the

also advocated as a means of shedding surface water during the filling sequence, thereby

assisting in leachate management by reducing infiltration.

3.15 Final Cover

A landfill cover is usually composed of several layers, each with a specific function. The final

cover system must enhance surface drainage, minimize infiltration, vegetation and control the

release the landfill gases. The landfill cover system to be adopted will depend on the gas

management plan i.e. (a) controlled passive venting; (b) uncontrolled release; or (c) controlled

collection and treatment/reuse.

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3.16 Ground Water Monitoring Wells around a Landfill

Groundwater samplers are used for groundwater monitoring through a certain set of wells

around a landfill.

A minimum of 4 sets of ground water monitoring wells (one up-gradient and three down

gradient) for sampling in each acquifer are considered desirable at each landfill site as per

recommendations of Manual on MSW Management by MoOD, Govt. of India.

3.17 Surface Water Drainage System

Surface water management is required to ensure that rainwater run-off does not drain into the

waste from surrounding areas and that there is no water logging/ ponding on covers of landfills.

The final cover should be provided a slope of 3 to 5% for proper surface water drainage.

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3.18 Post Closure Use of Landfills

After the closure of landfill site, it can be used in a number of ways some of which are

mentioned as following-

Parks

Golf Courses

Residential buildings (after proper geotechnical investigations)

Recreational Areas

Retail sites

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CHAPTER 3

Result and Analysis

3.1 Census Data for Allahabad city

We have collected the census data from websites of Census data and forecast the population

for Allahabad in 2021.For forecasting we have used Arithmetic Increase Method as it is

best suitable method for an old city. Following are the data and calculation:

Table 3.1 Census data for Allahabad City

Year Population Increase in population

(x)

1971

1981

1991

2001

2011

513036

650070

844546

975393

1117094

137034

194476

130847

141701

Total 604058

Average Increase Per Decade X=604058/4

=151014.5

Using Incremental Increase Method

Population in 2045 using Incremental Increase Method

P2045 = 1594871

P2035 = 1460899

P2025 = 1321244

3.2 MSW Data for Allahabad City:

We went to Allahabad Waste Processing Co. Pvt. Ltd. To collect the monthly MSW data

for a year to estimate the

project report design of bioreactor landfill for allahabad city

Documents