Plastic Waste - Fuel. Municipal Solid Waste Management

TABLE OF CONTENTS

Abstract

Acknowledgements

List of Figures

List of Tables

Abbreviations

Chapter - 1 Introduction
1.1 MSW Generation in India
1.1.1 Future MSW Generation in India
1.1.2 Waste Generation and the Associated Problems in India
1.2 Problems
1.2.1 Land Requirements
1.2.2 Methane Emissions
1.3 MSW Collection in India
1.4 MSW Disposal in India
1.4.1 Waste Transportation Services
1.5 Organization of the Ph.D. Thesis
1.6 Research Objectives of Present Study

Chapter-2 Review of Literature
2.1 Generation of MSW
2.1.1 Composition
2.1.1.1Composition of MSW in India
2.1.1.2General Characteristics of MSW in India
2.1.1.3 Chemical Characteristics of MSW in India
2.2 Management of MSW
2.2.1 An Over View of Current Mgt. Practices of MSW in India
2.3 Features of Indian MSW
2.4 Possible Waste Management Options
2.4.1 Wealth from Waste
2.4.2. Sanitary land filling
2.4.3 Recycling of Waste
2.5 Generation of Energy
2.5.1 Electricity Demand & Supply Scenario
2.5.1.1. Present Scenario
2.5.1.2 Future Scenario
2.6 Generation of Vermin composting
2.6.1 Process
2.7 Generation of fuel from Waste Plastic
2.7.1. Evolution of Strategies in Combustion

Chapter-3 Experimental Methodology
3.1 Study Area
3.2 Materials
3.2.1 Generation
3.2.2 Per Capita Generation of MSW
3.2.2.1 Collection and analysis of Samples
3.2.2.2 Estimation of per capita Hh’s MSW
3.3 Regression Analysis
3.3.1 Correlation
3.3.2 Scatter Diagram
3.3.3 Lines of Regression
3.3.4 Regression Analysis of Garbage
3.4 Waste to Energy
3.4.1 Quartering Method
3.4.2 Calorific Value
3.5 Vermin Compost
3.5.1 Generation of Vermin Compost
3.5.2 Multiplication of Earth Worms
3.6 Fuel Generation from Waste Plastic
3.6.1 Preparation of Plastic Diesel Blends
3.6.2 Experimental setup & Experimentation
3.6.2.1 Equipment used in Experimental Setup
3.6.2.2 Direct Injection Diesel Engine
3.6.2.3 Engine Loading System
3.6.2.4 Speed & Crank Angle Measurement
3.6.2.5 Temperature Measurement
3.6.2.6 Piezotronic Transducer
3.6.2.7 Exhaust Gas Analyzer
3.6.2.8 Technical Specifications
3.6.2.9 Smoke Density Tester
3.6.2.10 Experimental Procedure
3.6.2.11 Fuel Consumption Measurement
3.6.2.12 Combustion Pressure Measurement
3.6.2.13 Emission Measurement
3.6.2.14 Smoke Measurement
3.6.2.15 Exhaust Gas Temperature Measurement
3.7 Summary

Chapter-4 Results and Discussions 88
4.1 Generation of MSW
4.1.1. Questionnaire Results
4.2 Waste to Energy
4.2.1. Graphs Comparing Calorific Values
4.2.2 Net Power Calculation
4.3 Waste to Compost
4.3.1 Applications of Vermin Compost
4.3.2 Total Quantity of Vermin Compost at MCE
4.3.3 Cost Analysis
4.3.4 Estimate of Expenditure
4.4 Waste Plastic to Fuel
4.4.1 Implementation of Plastic Diesel Blends
4.4.1.1 Performance Analysis
4.4.1.2 Combustion Analysis
4.4.1.3 Analysis of Emission Parameters
4.4.2 Implementation of Plastic Diesel with Cetane Improver
4.4.2.1 Performance Analysis
4.4.2.2 Combustion Analysis
4.4.2.3 Analysis of Emission Parameters

Chapter-5 Summary &Conclusions
5.1 Summary
5.2 Conclusions
5.3 Recommendations
5.4 Future Scope of work

Chapter-6 References

List of Publications xvii Appendices

Appendix-A

Appendix-B (B1-B2)

Appendix-C (C1-C2)

Appendix-D

Appendix-E

Appendix-F (F1-F7)

Appendix-G (G1-G32)

ABSTRACT

Solid waste is an unwanted byproduct of modern civilization. Under the present scenario of MSW management in A.P, the status of present MSW management in Municipal Corporation of Eluru is studied in this work and some experimental studies were conducted in the following areas with an objective of better utilization of waste into a useful resource.

1. To find out the quantification and composition of MSW
2. To estimate the power generation potentiality from MSW
3. To estimate the possible revenue from vermin compost if prepared from the bio-degradable waste and
4. To study the combustion, performance and emission analysis of plastic

diesel derived from waste plastic as an alternate fuel at different fuel injection pressures in comparison with neat diesel.

A total of 279 household samples were collected for 7 days and a total of 250 questionnaire forms were collected out of 279 households in six (12% of total divisions) divisions. The correlation analysis is done in all the six division to analyze the variation of MSW with respect to income and members. It is estimated that 70 to 75 tons of waste is generated per day and against this around 60 tons of waste is being collected by MCE. The per capita Hh’s generation of MSW is estimated as 138.5 gm per day. A representative sample of the corporation using quartering method is collected from the dump yard. The representative sample of MSW was subjected to both proximate and ultimate analysis to assess the calorific value of MSW to estimate the potential of energy generation at MCE. It is estimated that by using solid waste in MCE, nearly 3MW of power can be generated. Pulverization of municipal solid waste is done and the pulverized solid waste is dressed to form a bed and the bed is fed by vermi’s which converts the bed into vermi compost. The obtained vermi compost is sent to a recognized MoEF lab for estimating the major nutrients and micronutrient values . It is estimated that 60 tons of waste is generated in Eluru per day and if this waste is converted to quality compost, 9.60 tons of vermin compost can be generated.

The segregated plastic waste (4% of MSW) collected from the study area was sent to Prof. Alka Umesh Zadgaonkar, Nagpur for conversion of thermo plastics into liquid fuel oil. The fuel oil extracted by the process developed by Prof. Zadgaonar is subjected to fractional distillation at 110° to 260° C in the laboratory (study area) to convert the plastic liquid hydro carbons to plastic diesel (PD). In this research work, the diesel derived from the plastic waste is implemented as a fuel for the conventional diesel engine, with some modifications like blends with diesel, with cetane number improver and change of injection pressure for combustion, performance and emission analysis. At each case performance, combustion and emission parameters are taken and they are compared with neat diesel at standard injection pressure of 200bar. It is concluded that the collection efficacy of MSW in the study area needs to be improved. There is need to adopt the contemporary MSW management practices like vermin composting and generation of energy through energy pellets in the urban areas. Though extraction of plastic diesel is a handy option more research is needed to consider the option as a regular management option for MSW.

ACKNOWLEDGEMENTS

The author wishes to thank all those who in diverse ways have offered assistance and advice during the course of study and in the preparation of this thesis. I take this opportunity to put on record my most sincere sense of reverence and gratitude to my Research Director, Prof. K. Venkata Subbaiah, Department of Mechanical Engineering, College of Engineering, Andhra University for his invaluable comments. The study would never have been achieved to its present shape with out the personal encouragement and gracious supervision of Prof. K. Venkata Subbaiah. My special thanks go to Prof. P. V. V. Prasada Rao, the Department of Environmental Science, Andhra University, the Joint Director of my research work. He has been extremely generous for allowing me to provide fruitful guidance in this regard.

My sincere thanks go to the Vice Chancellor, Andhra University, the Head of the Department of Mechanical Engineering, Prof. B.S.K.Sundara Siva Rao, Andhra University, Prof.M.M.M.Sarkar ,the chairman, Board of studies of Dept. of Mech. Engg, and all the teaching faculty of the department for their immense contribution to my successful completion of my thesis.

My special thanks are due to Prof. Alka Zadgaonkar and Sri Umesh Zadgaonkar, Nagpur for their timely support of liquid hydrocarbons derived from plastic waste for my experimental work.

I would be failing in my obligation if I do not thank my organization and the management of Sir C.R. Reddy Institutions, Eluru for extending their co-operation and encouragement in my work.

I would like to extend my sincere thanks to the management of K.L.Univesity, Vijayawada for permitting me to conduct my experimentation with plastic diesel derived from plastic waste on their equipment.

I also owe deep sense of gratitude to Dr. V. J. Joshua Prasad, GMRIT, Rajam and Dr. R. R. Srikanth, Githam University, Dr. K. Ramanjaneyulu and Prof. M.A.S.Srinivas, JNTUH, Dr.K.Ravi, Principal, Dhanekula Inst.of Technology, Vijayawada for their proffered and valuable suggestions in my research.

With great complacency, I place on record the co-operation I have received from various people and institutions. I express my gratitude to all the concerned authorities of libraries of IIT, Chennai and NEERI, Nagpur.

I am extremely grateful to all the house holders of the divisions of MCE for participating and cooperating and responding to my interview schedule and sparing their valuable time in my field work.

I also wish to thank the Commissioner, Municipal Councilors and Staff of MCE, Eluru for their kind help and data support during the field work. I will never forget the co-operation of our non-teaching staff of Sir C.R. Reddy College of Engg., Eluru and K.L.University, Vijayawada. My special thanks are due to Sri A. Krishna Mohan, Sri V.Maruthi Prasad, Sri Ch. Srinivasa Rao, Sri T.Yasebu, Sri V.Hari Babu and Sri B.Yesu Das.

I also wish to thank Sri Ch. Vijaya Kumar, Sri V. Pavan Kumar, Sri T. Srinivasa Rao and Sri K. Kumar for taking much strain while editing my thesis. My special thanks to Dr.D.V.Rao, Sri D.Satyanayana, Sri K.Narasinga Rao, Dr.A.Yesu Babu, Prof.Y.V.S.S.S.V.Prasada Rao, Prof. A. Sri Hari Prasad, Dr.K.Ramesh Raju, Sri A. Arshad, Sri N.R.K.Prasad, Sri T.V.V. Satyanarayana, Dr.Y.Jagan Mohan Rao, Prof.A.Anand Kumar, Principal, SCRRCOE, Sri Kakarala R.V.Prasada Rao, Secretary, Sri Chava Ramakrishna, President, Sri Jasti Harinath, Correspondent of Sir C. R. R. Institutions and my uncle, Sri K. P. P. Rao and many more whose logistic support was quite resourceful in the culmination of this study. My hearty thanks to my wife, Anupama and my daughters Manojna and Sri Prajna for their encouragement and moral support.

On this auspicious moment, I seek the blessings of my parents Sri Jasti Raja Rama Mohana Rao and Smt.Jasti Aruna Kumari and my departed elder brother late Jasti Ravi Prasad. My Special thanks to my parents, who have been an inspiration for me and ensured that I got the best opportunities in life. With out their exemplary patience and encouragement, completing Ph. D would have remained only a daydream to me. My heart is filled with submission and indebtedness. With all humiliation and pride, I dedicate this work to my father and mother.

Thank you all including those I could not mention here.

Jasti Sudhir Kumar

LIST OF FIGURES

Figure1.1 The projection quantities of municipal solid waste under the BAU scenario

Figure 1.2 Cumulative land requirement for disposal of MSW (km2)

Figure 1.3 MSW lying in an open dump yard at MCE

Figure 1.4 MSW collection at MCE

Figure 2.1 Characteristics of current MSW in Low-Income

Figure 2.1a Characteristics of MSW in India in 1973

Figure 2.1b Characteristics of MSW in India in 1995

Figure 2.2to2.9 Power Projects in India from MSW 37-

Figure 2.10 All-India Power Supply Position (Energy) till 2016-17

Figure 2.11 Composition of Municipal Solid Waste in India (NSWAI)

LIST OF TABLES

Table 1.1 Waste generation per capita in Indian cities

Table 1.2 Waste generation in selected countries

Table 1.3 Waste collection efficiency in Indian cities

Table 1.4 Methods of disposal of municipal solid waste in selected 13 countries (%)

Table 2.1 Physico-chemical characteristics of Indian MSW

Table 2.2 Chemical comparison of waste in developing and 22 developed countries

Table 2.3 Composition of municipal solid waste in Indian cities

Table 2.4 Nutrient composition of vermin compost and garden compost

Table 3.1 Composition of the MSW in MCE

Table 3.2 Dimensions of Vermi Bed

Table 3.3 Properties of Plastic Diesel fuel as per the test report of ARAI

Table 3.4 Specifications of the DI- Diesel Engine

Table 3.5 Measuring ranges and calibration values of PEA 205

Table 3.6 Precision levels achievable by PEA 205

Table 3.7 Resolution provided by PEA 205

Table 4.1 Generation of MSW/day in the six sample divisions

Table 4.2 Weighing List of MCE Collection Vehicles

ABBREVATIONS

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INTRODUCTION

India, a fast developing nation in the world is poised to increase its general prosperity and standard of living and in the process is increasing its consumption levels of energy and consumer goods. Harboring 16.8% of World’s population (est. 2006) in a little over 2.2% of the world’s land mass(CIA,2007).The present consumption pattern certainly put lot of strain on the environment in general and natural resources in particular. Increased levels of consumption of energy and consumer goods generate large quantities of solid, liquid and gaseous materials where in they have no immediate utility at the place of generation. These materials are commonly termed as Solid wastes and those that are generated from the House Holds are known as Municipal Solid Wastes.

Municipal Solid waste is the organic and inorganic waste materials produced by different sources and have lost their value in the eyes of their owner (Ghosh, 2004). It is a complex mixture of different substances (El Fadel and Sbayti.H ., 2000; Rushton, 2003). MSW is made up of different organic and inorganic fractions like food, vegetables, paper, wood, plastics, glass, metal and other inert material (Mor, 2006). Municipal Solid Wastes comprises mostly household waste and it may include some commercial and industrial wastes. In general, the quantity of MSW is currently has been increasing year after year throughout the world , presenting a growing problem for local authorities necessitating new legislation, which limits indirectly the amount of mixed MSW that can be sent to landfill, is coming into effect.

In India, as in other developing countries, solid waste management and sanitation are the least prioritized public services. These services are necessary for preventing the spread of diseases, promoting general well being, and improving the standard of living. However, due to lack of knowledge about the linkages of waste management to public health and environmental protection, unwillingness on the part of the local officials to take necessary action, and a lack of funds for implementing and maintaining best practices like wealth from waste, waste management has not received the attention it requires rapidly and its composition is also changing. At the time of independence (1947), cities and towns in India generated an estimated 6 million tones of solid waste, while in 1997; this has grown to, 48 million tones. In India, more than 25% of the municipal solid waste is not collected at all; 70% of the Indian cities lack adequate capacity to transport it and there are very few sanitary landfills to dispose the MSW. Even the existing landfills are neither well equipped nor well managed and are not lined properly to protect against contamination of soil and groundwater.

Until recently, environment was not a big issue in a country like India and solid waste management was definitely not the prime concern of environmentalists and the governments. It is only in very recent times, the realization has dawn since it is unequivocally proved that the management of municipal solid wastes are very closely linked to public health and hence GDP (Shuchi gupta et al., 1998).The Indian policy makers realized the importance of environmental management when the pathetic state of municipal waste services was highlighted mostly by the NGO sector and independent research groups highlighting its environmental/ ecological problems. This changed the outlook of Indian policy makers, politicians, public and private sectors and the general public at large towards Municipal Solid Wastes; right from its generation point down to its management.

India, seventh largest country in the world with a land mass of 3287263 km, is also the second most populous country in the world. Lying entirely in the northern hemisphere, the Indian mainland extends between latitudes 8° 4% and 37° 6% north, longitudes 68° 7% and 97° 25% east and measures about 3214 km from north to south between the extreme latitudes and about 2933 km from east to west between the extreme longitudes. It has achieved multifaceted socio-economic progress during the last 63 years of its independence and emerged as the tenth industrialized nation in the world, and is completely self-sufficient in food grains. India’s population, as on March1991 stood at 1065.07 million (July 2004 est.) (TERI, 1997), making it the second most populous country of the world after China. Assuming an annual growth rate of 1.3%, the estimated figures for 2021 AD are 1296.8 million (Eduard.V.et al., 1993). The current per capita GDP figure is Rs. 3197.21 and is projected to increase to Rs. 11599.7 by 2021 (unpublished data, TERI). The quantum of waste generated in the country is increasing day-by-day on account of its increasing population and increased GDP; correspondingly the civic services have not been expanding proportionately and hence are under tremendous pressure.

The most common types of waste treatment and final disposal are materials recycling, composting, incineration and land filling (Marchettini, 2006, Burnley, 2006). Nowadays refuse no longer is simply considered as waste, but rather something that must be recovered or re-used as a potential resource (Riva and Tiezzi,1997, Dijkema et al ., 2000, Korhonen et al., 2004). Efficient planning for municipal solid waste management system requires accounting for the complete set of environmental effects and costs associated with the entire life cycle of MSW (Emery et al., 2006). For such a system to be truly effective it needs to be environmentally compatible, economically viable, socially acceptable and sustainable (Nilsson-Djerf and McDougall, 2000).

1.1 MSW Generation in India:

The amount of waste generated in a country is directly proportional to economic growth and consumption levels. Since the GDP is low the low-income countries generally consume fewer goods and hence generate less waste than developed countries. It is also observed that low-income countries also generally use less recyclable materials, especially in packaging. In the mid-nineties, the average waste generated in urban areas in India was estimated to be approximately 0.46 kg/person/day (Singhal, S. and Pandey S., 2001 and World Bank, 1999). The Ministry of New and Renewable Energy (MNRE), formerly known as the Ministry of Non conventional Energy Sources, estimated that approximately 42 million tons of MSW are generated in the urban areas of India annually (Ministry of New and Renewable Energy, Govt. of India). The data in table 1.1 shows the relationship between the size of an urban area and per capita of waste generation. Larger cities tend to produce higher amounts of waste per capita than smaller ones because both per capita incomes and consumption levels are higher in urban areas (World Bank, 1999 and Ministry of Urban Development, 2000).

Table 1.1: Waste Generation per capita in Indian Cities

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Urban waste generation in India tends to be lower compared to other

developing countries and approximately one-third to half that of developed countries (Asnani, P.U. 2006). In low-GDP countries, MSW generation rates range from 0.4-0.9 kg/person/day, while in high-income countries it’s approximately 1.1-5.0 kg/person/day. At present, India’s waste generation falls on the lower end of the range, as shown in table 1.2 ( World Bank, 1999) and this may be due to the fact that majority of the population still lives in rural areas ( Census of India 2001).

Table 1.2: Waste Generation in Selected Countries (kg/person/day)

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1.1.1 Future MSW Generation in India:

Waste generation in India is expected to increase rapidly since more people are migrating to urban areas and as income levels are increasing, consumption levels are likely to raise, hence the rates of waste generation. This has significant impacts on the amount of land that is and will be needed for disposal, economic costs of collecting and transporting the waste, and the environmental consequences of increased MSW generation levels.

It is estimated that the amount of waste generated in India will increase at a per capita rate of approximately 1-1.33% annually (Singhal, S. and Pandey S., 2001). A World Bank publication reports that the waste generation rate in urban areas of India will be approximately 0.7 g/person/day by 2025, which is roughly four to six times higher than it was in 1999 (World Bank, 1999). There has been a significant increase in MSW (municipal solid waste) generation in India in the last few decades.

This is largely attributed to the rapid population growth and economic development in the country. Solid waste management has become a major environmental issue in India in general and urban centers in particular. The per capita of MSW generated daily, in India ranges from about 100 g/person/day in small towns to 500 g/person/day in large towns/cities. Though, there is no national level data for MSW generation, collection and disposal, and increase in solid waste generation, over the years, can be studied for a few urban centers. For example, the population of Mumbai grew from around 8.2 million in 1981to 12.3 million in 1991, registering a growth of around 49%. On the other hand, MSW generated in the city increased from 3 200 tons per day to 5 355 tons per day in the same period registering a growth of around 67% (CPCB2000). This clearly indicates that the growth in MSW in our urban centers has outpaced the population growth in recent years. This trend can be ascribed to our changing lifestyles (traditional to throw away culture), food habits, and change in living standards.

MSW in cities is collected by respective municipalities/local governments and transported to designated disposal sites, which are normally low lying areas on the outskirts of the city. The limited revenues earmarked for the municipalities make them ill-equipped to provide for high costs involved in the collection, storage, treatment, and proper disposal of MSW. As a result, a substantial part of the MSW generated remains unattended and grows in the heaps at poorly maintained collection centers. The choice of a disposal site also is more a matter of convenience i.e. what is available than what is suitable. The average collection efficiency for MSW in Indian cities is about 72.5% and around 70% of the cities lack adequate waste transport capacities (TERI, 1998).

The unscientific and in-sanitary methods adopted for the disposal of solid wastes is, therefore, a serious health concern in India. The poorly maintained landfill sites are prone for groundwater contamination because of leachate production. Open dumping of garbage facilitates the breeding for disease vectors such as flies, mosquitoes, cockroaches, rats, and other pests (CPCB, 2000).The municipalities/local governments in India therefore face the challenge of reinforcing their available infrastructure for efficient MSW management and ensuring the scientific disposal of MSW by generating enough revenues either from the generators or by identifying activities that generate resources from waste management.

1.1.2 Waste Generation and the Associated Problems in India:

In India, the amount of waste generated per capita is estimated to increase at a rate of 1%-1.33% annually (Shekdar, 1999). Figure 1.1 depicts the rising quantities of municipal solid waste from 1997 to 2047 under the BAU scenario assuming the daily per capita waste generation in 1995 as 0.456 kg (EPTRI, 1995) and the per capita increase in waste generation as 1.33%.

The calculated value of daily per capita waste generation in 1997 was 0.468 kg. Figure 1.1 projects that the total waste quantity generated in 2047 would be approximately above 260 million tones—more than five times than the present volume of solid waste generation. This increase will have significant impacts in terms of the land required for disposing this waste as well as on methane emissions.

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Figure 1.1: The Projection Quantities of MSW under the BAU Scenario

Source: TERI information monitor on environmental science 6(1): 1-4

1.2 Problems:

1.2.1 Land Requirement:

The burden that the increase in solid waste generation would impose is evident from the fact that the cumulative requirement of land (base year 1997), for disposal of MSW, would amount to around 1400 km2 by 2047 (Figure 1.2). The estimates under the BAU scenario are made considering the average collection efficiency of waste at 72.5%, average depth of landfill site as 4 m, and average waste density as 0.9 tons/m3 (NIUA,1989). Diversion of land for waste disposal would be physically impossible since areas with the largest concentration of solid waste would also be the areas with serious scarcity of vacant land. The implication, therefore, is that if the current methods of solid waste disposal persist, the waste would have to be carried over long distances, which would require the creation of a great deal of transport facilities and infrastructure. This would involve enormous additional finances.

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Figure 1.2: Cumulative Land Requirement for Disposal of MSW (km2) Source: TERI information monitor on environnemental science 6(1): 1-4

1.2.2 Methane Emissions:

Indiscriminate land filling leads to deterioration of water quality in neighborhood areas of landfill sites due to contamination by leachates from the landfills. This has adverse health impacts on people living nearby, causes offensive odors, and the people living nearby live in the constant fear of explosion of methane gas that can accumulate at the landfill sites. Landfill gas, which is 50%-60% methane, contributes significantly to global warming. It is estimated that in1997, the landfills released about 7 million tones of methane into the atmosphere, which would increase to 39 million tons by 2047 under BAU scenario Emissions have been calculated using Bingemer and Crutzen’s(1987) approach, which assumes that 50% of the carbon emissions in the landfills is transformed into methane.

1.3 MSW Collection in India:

In the absence of modernization and atomization of waste management services and its various components like collection, transportation and disposal continue to be labor-intensive activities in India. About 80% of the total budget of all municipal corporations/local governments is accounted for by the salaries of sanitation workers engaged in road sweeping and related activities. A survey of 159 cities conducted by the National Institute of Urban Affairs (NIUA) in 1989 revealed that the waste collection efficiency in these cities varied from to 77% and the national average was a poor

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Figure 1.3: MSW lying in an open dump yard at 66% MCE

72.5%, as compared to the developed countries

where the waste collection is almost complete except for the most rural areas. Figure1.3 shows the present MSW management scenario in the study area of MCE. Waste collection efficiency is a function of two major factors; manpower availability and transport capacity. Less than 10% of the 157 cities surveyed in 1989 had more than 2800 workers: million populations which is an accepted benchmark of optimum workforce requirement, by most of the municipal corporations in India. Data of Bhoyar paper and the NIUA study has been compiled in table 1.3 to give a percentage wise breakdown of the cities for manpower shortfall and transport carrying capacity shortfall. Though, the cities perused in both the studies are not exactly similar and the data for both refers to different time periods, in the absence.

Table 1.3: Waste Collection Efficiency in Indian Cities (NIUA, 1989)

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Man power shortfall calculations are based on benchmark of 2800 workers/one million population and transport volume shortfall calculations are based on the figure of 320 m3 transport capacity requirement for one million population. (Bhoyar et al., 1996).

The Solid Waste Manual published in 2000 by the Ministry of Urban Development (MUD) states that, “In India, the system of primary collection of waste is practically non-existent …thus streets are generally treated as receptacles of waste…”.Most cities lack primary collection systems. MSW is often left on the streets or in community bins that are overflowing. House-to-house collection of MSW is carried out in only some locations in large cities in India. A large portion of the waste is collected by street sweeping, which is not done on a daily basis in many areas.

Compared to developed nations, where the majority of the waste is collected, most low-income countries have collection efficiencies ranging from 30-60% (Singhal, S. and Pandey S., 2001). However, the collection efficiency in India ranges from 50-90%. A survey of the Indian cities in 1989 revealed that the average collection efficiency was 72.5%. However, given the results of the survey, as shown below, the national average must have been considerably lower than 72.5% (Gupta .S et al., 1998).

A study conducted by the National Institute of Urban Affairs of India in 1989 found that collection efficiencies in Indian cities were low due to two main factors: availability of labor and transportation facilities (NIUA, 1989). Using a benchmark of 2,800 workers/million population for an optimum manpower requirement, the survey found that less than 10% of the cities surveyed met this requirement, and that over 77% of the cities had a shortfall of at least 46% with regard to transportation, another survey used a benchmark of 320 m3/million population for community waste bin in Mumbai transport volume. This survey concluded that 95% of the cities had a shortfall ranging from 22-53%, and that 5% of the cities had a shortfall of over 68%. A more recent study in 2006 found that 70% of urban areas in India lack proper transportation facilities to transfer MSW to disposal or dumping sites (Loikala et al., 2006).

1.4 MSW Disposal in India:

In most cities and towns in India, MSW is disposed in open dumps in an unregulated and unscientific manner in low-lying areas on the outskirts of the cities. Most dumps lack systems for leachate collection, landfill gas collection or monitoring, nor do they use inert materials to cover the waste (Asnani.P.U, 2006, MUD, 2000). This results in groundwater contamination from leachate, surface water contamination from runoff and lack of covering, air pollution caused by fires, toxic gases, and odor, and public health problems due to mosquitoes and scavenging animals (MUD, 2000). Apparently, India is not the only country lacking of proper waste management systems. Open dumping is commonly practiced in developing countries. It is estimated that in low-income countries, less than 25% of wastes are sent to regulated landfills (Cointreau. S, 2006). Table 1.4 shows a comparison of disposal methods in some developing countries. These countries are the same as those shown in table 1.2 on waste generation (UNESC, 2000).

Table1.4: Methods of Disposal of Municipal Solid Waste in Selected Countries (%) ( World Bak,1999)

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1.4.1 Waste Transportation Services:

In India, the local governments are entrusted with the Municipal solid waste management. Transportation of waste is carried out by the municipalities/municipal corporations employing vehicles including open trucks,

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Figure1.4: MSW Collection at MCE

tractor-trailers, tipper trucks, dumper trucks and animal drawn carts (mostly in small towns and rural areas). The recent trend in big cities/municipal corporations and towns is however, towards using container- carriers and dumper-placers, wherein the containers of the vehicles are them selves the community bins. The present waste collection mode at the study area of MCE is shown in figure1.4.The volume of the waste to be transported is generally expressed in the terms of cubic meter per million of population. Studies made on the basis of waste density, waste generated etc. indicate that on an average 320 m3 of transportation capacity is required for daily transportation of waste generated by population of one million. The compilation and analysis of the data of 44 Indian cities in 1996 by bhoyar et al, 1996, indicates that 70% of these 44cities do not have the 320 m3/million transport capacity. This percentage might best ill higher as the vehicular fleet of most of the cities is several years old and is off the road for a large proportion of the year for want of repairs. Table 1.4 shows the various methods of disposal of MSW in Asian countries.

MSW Management is the major problem being faced by municipalities because it involves a huge expenditure and receives scant attention (Bhide and Sundersan, 1983). It is not only a technical problem but it also is strongly influenced by political, legal, socio-cultural, environmental and economic factors, as well as available resources. Moreover, these factors have interrelationships that are usually complex in waste management systems (Kum et al., 2005). Many cities in developing Asian countries face serious problems in managing their solid waste. The annual waste generation increases in proportion to the rise in population and urbanization, and issues related to disposal have become challenging as more land is needed for the final disposal of these solid wastes (Idris et al., 2004).MSW is normally disposed of in an open dump in many Indian cities and towns, which is not the proper way of disposal because such crude dumps pose many environmental hazards causing ecological imbalances with respect to land, water and air pollution (Kansal et al., 1998). Increasing population levels, rapid economic growth and rise in community living standards will accelerate the future MSW generation rate within Indian cities. The present annual quantity of solid waste generated in Indian cities has increased from 6 million tons in 1947 to 48 million tons in 1997 with an annual growth rate of 4.25%, and it is expected to increase to 300million tons by 2047(CPCB, 2004).Improper management of MSW constitutes a growing concern for cities in developing countries. Proper management requires the construction and installation of essential facilities and machinery, based on a suitable management plan (Shimura et al., 2001). More than 90% of MSW in India is directly disposed of on the land in an unsatisfactory manner (Das et al., 1998). The problem is already acute in cities and towns as the disposal facilities have not been able to keep pace with the quantum of wastes being generated. It is common to find large heaps of garbage lying in a disorganized manner at every nook and corner in the cities (Kansal, 2002).

1.5 Organization of the Ph.D. Thesis:

The Ph. D thesis is organized into six chapters; Introduction, Review of literature, Materials and Methods, Results and discussions with emphasis on vermin composting, energy from waste, implementation of plastic diesel from waste plastic on a diesel engine followed by summary, conclusions &recommendations. At the end references are presented.

Chapter I: The chapter I on Introduction includes general information on solid waste generation, collection, composition of solid waste in the study area the present state of management in the third world countries especially India. The rearch objective is presented in the chapter.

Chapter II: The chapter II on Review of literature presents the research work carried out by the earlier researchers as well as the contemporary studies relating to MSW. Information relating to earlier management options on MSW and present approaches on MSW is discussed. An attempt is also made to mention the problems associated in the management of MSW.

Chapter III: The chapter III on Experimental Methodology has discussed the materials collected and the methods adopted for the present study. The methods employed for sample collection, quantification and composition of MSW in the present study is included. The variation of MSW generation with respect to socio economic factors like income and family members is also discussed and correlated.

The methodology for the preliminary estimate of potential energy recovery from waste and vermin compost from biodegradable part of the waste is discussed. The chapter also deals with experimental procedures on the use of plastic diesel derived from waste plastic component on a direct injection diesel engine to study the performance, combustion and the composition of the exhaust gases with a comparison to a normal diesel fuel.

Chapter IV: The chapter IV on Results and Discussion has illustrated the results obtained in the present study along with the discussion. Data relating to quantification of MSW, the perception of the households on various aspects of MSW, the potential of power generation from MSW and the quantity and composition of vermin compost generated from the biodegradable fraction of MSW are presented. Apart from the above, the test results obtained by the usage of plastic diesel derived from waste plastic component of MSW on a direct injection diesel engine are presented on its performance, combustion and emission analysis at different fuel injection pressures and blends with petro diesel as well as cetane improver. Basing on the results appropriate discussions were presented.

Chapter V: The chapter V on Summary, Conclusions & Recommendations has taken into account a brief of the work done in the present study and the conclusions drawn based on the generation of data. An effort is also made to suggest possible and feasible recommendations to improve the management of MSW.

Chapter VI: The chapter VI on References presents the list of references.

1.6 Research Objectives of the Present Study:

Keeping in view the present environmental and social problems caused by the disposal and management of MSW and the fast depletion of fossil fuel resources, the present work has been under taken with the following objectives.

1. Systematic and scientific evaluation of MSW from Eluru, a class III city in Andhra Pradesh with reference to
a) Quantity and quality
b) Per capita Hh’s waste generation
2. To estimate the power generation potentiality from MSW
3. To estimate the possible revenue from Vermin compost if prepared from the bio-degradable waste and
4. To study the combustion, performance and emission analysis of plastic diesel derived from plastic waste as an alternate fuel at different fuel injection pressures in comparison with neat diesel.

REVIEW OF LITERATURE

India, the tenth largest industrialized nation in the world is not only increasing its consumption levels of energy and consumer goods but also generating large quantities of Municipal Solid Wastes. MSW contains a spectrum of materials that includes organic and inorganic fractions like food, vegetables, paper, wood, plastics, glass, metal and other inert material (Mor, 2006). Municipal Solid Wastes comprises mostly household waste and sometimes it may include some commercial and industrial wastes. In general, the quantity of MSW generation has been increasing year after year presenting a growing problem for local authorities/governments necessitating new legislation, which limits indirectly the amount of mixed MSW that can be sent to landfill, is coming into fore.

2.1 Generation of MSW:

The generation of MSW mainly depends on population and people’s living standards (Grossmann et al., 1974, and Wertz, 1976) and income level (Medina, 1997). Generation of MSW is identified as an inevitable consequence of production and consumption activities related to the level of income and urbanization (Wang and Nie, 2001). Socio-economic factors like persons per dwelling, their cultural patterns, education and attitudes (Grossmann et al., 1974, Al-Momani, 1994) have a say on MSW generation.

In India, the amount of MSW generated per capita is estimated to increase at a rate of 1.0-1.33% annually (Shekdar, 1999) and its disposal has become a daunting task as more land is required for its disposal (Kumar et al., 2009). According to estimates (TERI, 1998) the annual generation of MSW in India would be more than 260 million tons by 2050, which needs an additional area of 1400km2 for its disposal, most of it in urban areas.

2.1.1 Composition:

2.1.1.1 Composition of MSW in India:

In general Municipal solid waste in India has a high percentage of organic matter and a low recyclable content. It also contains high amounts of ash due to the use of traditional biomass sources for fuel and heat and other inert materials.

2.1.1.2 General Characteristics of MSW in India:

MSW in India is similar to that of other under developed/low-income countries and consists mostly of organic matter and inert materials, as presented in figures 2.1, 2.1a and 2.1b. Under developed/ low-income countries generally have a high proportion of organic matter ranging between 40-85%. Ash and other inert materials usually range from 45-54% and make up the second largest proportion of waste due to the use of wood, charcoal, and other biomass as household fuel sources (World Bank,1999).The composition of waste depends on a wide range of factors such as food habits, cultural traditions, lifestyles, climate and income etc. The variations due to such factors are found across different countries as well as across different regions within a country. The inter-regional variations are, however, not as marked as those across the countries. Variation also occurs within a region over the years as a consequence of economic and social changes. India is no exception to this, and the data given in table 2.1 clearly shows the changes in the composition of Indian MSW over a time period of about 25 years.

Table 2.1: Physico-chemical Characteristics of Indian MSW (Bhide and Sundaresan, 1983 and EPTRI, 1995)

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The most remarkable change in the table 2.1 is the percentage of recyclables (plastic, metals etc.) which increased from 9.6% in 1971:73( World Bank,1999) to 17.2% in 1995 owing to changing lifestyles and the increasingly consumerist attitude of the common man in the country. This increase has given rise to the phenomenon of rag picking activity especially in the metro cities of the country where in the recycling units have mushroomed on the peripheral areas providing employment to thousands of unskilled labor.

The organic matter has more or less remained the same, whereas ash and fine earth has decreased corresponding to the increase in recyclables. A shift in energy resources consumption from coal and wood to petrochemical-based products could be a plausible explanation for the ash and fine earth percentage decrease.

The data presented in figures 2.1a and 2.1b show, the biggest changes in the composition of municipal solid waste in India between 1973 and 1995. The reason seems to be i) an increase in recyclable materials, such as plastics, glass, and paper, and ii) a decline in the proportion of ash and fine earth (Gupta et.al,1998 and World Bank 1999). The high fraction of inert materials is a result of street sweepings, silt, and construction and demolition (C&D) waste in municipal waste dumps (MUD, 2000)].

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Figure 2.1: Characteristics of MSW in low-income Countries

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Figure 2.1a: Characteristics of MSW India in 1973

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Figure 2.1b: Characteristics Current MSW in India in 1995

2.1.1.3 Chemical Characteristics of MSW in India:

The characteristics and composition of municipal solid waste are directly related to income levels, and the rate of MSW generation. Developed countries tend to have much larger fractions of recyclable materials compared to low-income countries (World Bank, 1999). This is primarily because of different consumption patterns and much higher use of packaging materials. As a result, the moisture content is lower and the heating value of the MSW is higher than in low-income countries. Table 1.6 shows a comparison of the moisture content, density (in trucks transporting MSW to the landfill), and the lower heating value (LHV) of the waste generated in developing and developed countries (Cointreau.S, 2006). A joint survey of 59 cities across India conducted by the Central Pollution Control Board (CPCB) and the National Environmental Engineering Research Institute (NEERI) in 2005-06 found that the moisture content in MSW was between 30-60%, which is within the range shown in table 2.2. The density of municipal solid waste in urban areas is estimated to be between 500-600 kg/m3, which are higher than the range given in table 1.6 (Loikala et al., 2006).

Table 2.2: Chemical Comparison of Waste in Developing and Developed Countries

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Table 2.3 summarizes the chemical characteristics of MSW in Indian cities as reported by NEERI in mid nineties (MUD, 2000). In large cities with higher levels of consumption of plastics and other non-organic matter compared to small towns and cities, it would be expected that the heating value of MSW would be high. However, the data presented in table 2.3 shows that the larger the city, the lower is the heating value (MUD, 2000). This may be attributed to two primary reasons:

i) In large cities, recyclable materials are collected by rag pickers before the

waste reaches the dumping yard, thus lowering the heating value of the waste; and In majority of the small towns, households use the organic fraction to make compost, thus increasing the heating value of the waste.

Table 2.3:Composition of Municipal Solid Waste in Indian Cities (MUD,2000)

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Mir Anjum Altaf et.al (1996) suggested an approach integrating demand-side information into the planning process and indicated that simple and inexpensive household surveys can provide valuable inputs into the planning process. The management of solid waste continues to be a major challenge in urban areas throughout the world, but particularly in the rapidly growing cities and towns of the developing countries (Foo, 1997). Developing nations are now seriously concerned with the consequences of improper handling of MSW (Sharholy et al., 2000, Shimura et al., 2001). Only 60% of the waste generated is actually collected in most Indian and Pakistani cities. The uncollected waste lies in topographic depressions, vacant plots, along streets, roads and railway lines, drains, storm drains and open sewers within overall urban limits.

A good amount of research work on SWM has already been done in Bangladesh (Salequzzaman et al., 1998, 2001, Salequzzaman, 2000, Ahmed and Rahman, 2000, Alam et. Al., 2002, Hasan and Chowdhury, 2005, Enayetullah et. Al., 2005, Rahman et. Al., 2006). Mohammad Sujauddin et al., (2008) studied Household solid waste characteristics and management in Chittagong, Bangladesh, and discussed that the management of MSW is a highly neglected area of the over- all environmental management in most developing countries (Murtaza and Rahman, 2000). Output method/ direct waste sampling method (Shanklin et al., 2002) and continual random sampling (Guven, 2001) were employed for calculating the generation rate and determining the physical composition of MSW. The method focused both on the sources of waste generation as well as on disposal sites.

It is estimated that annual MSW growth rate is 3.2-4.5% in developed nations and 2-3% in developing nations (Suocheng et al., 2001) and 46% of the global population is residing in urban areas (HMGN and MoPE, 2003) Apart from quantity, rapid urbanization and industrialization is also changing the characteristics of solid waste generated. As a consequence, the solid waste management system (SWMS) needs to be updated to suit the waste quality, quantity and composition. Composition of urban waste is changing with increasing use of packaging material and plastics (CPCB, 2003). Srivastava P. K. et al., (2005) have discussed a qualitative investigation using strengths, weaknesses, opportunities and threats analysis (SWOT) on the implementation of community participation in MSW management. This qualitative investigation emphasizes the limited capabilities of the municipal corporation’s resources to provide proper facilitation of the municipal solid waste management (MSWM) services without community participation in Lucknow city. The SWOT analysis was performed to formulate strategic action plans for MSWM in order to mobilize and utilize the community resources on one hand and the municipal corporation’s resources on the other.

Though there is no latest reporting (CPCB, 2006) of the total quantity of waste generated in the country (based on weighing exercise by local bodies) as per the manual on solid waste management (2000) Ministry of Urban Development has estimated waste generation in India to be 100,000 metric tons (MT). However CPCB in collaboration with the assistance of National Environment Engineering Research Institute (NEERI), Nagpur has conducted survey of solid waste management in 50 cities during 2004-05 covering 35 metro cities having population greater than 1 million and 24 state capitals. Studies have revealed that waste generation rate varies from 0.12 to 0.60 kg per capital per day. Analysis of physical composition indicates 40-60 percent of total compostable matter while renewable fraction was observed between 10 and 25 percent. The moisture content in the MSW was observed to vary from 30 to 60 percent while the Carbon/Nitrogen ratio was observed to be in the range of 20-10 .The higher calorific value on a dry basis ranged between 520Kcal/Kg to 3766Kcal/Kg.

Alternative approaches like community participation and public private partnership in waste management were suggested by Sarika Rathi (2006) in municipal solid waste (MSW) management and emphasized that community participation in waste management is the least cost option.

Rotich K. Henry et al., (2006) provided an overview of the state of municipal solid waste management (MSWM) in Kenya as a case study of a low-income developing country. Poor economic growth (1.1% in 1993) has resulted in an increase in the poverty level (presently stands at 56%), migration from the rural areas to the urban areas has resulted in unplanned settlements in suburban areas accommodating about 60% of the urban population on only 5% urban land area. The study has discussed the possible solutions that can be undertaken to improve municipal solid waste (MSW) services. He suggested that the involvement of stakeholders is important to achieve any meaningful and sustainable MSWM. The role of the informal sector through community-based organizations (CBOs), Non-Governmental Organizations (NGOs) and the private sector in oơering solutions towards improvement of MSWM is explored.

Composition and characterization of MSW is a prerequisite for devising and implementing proper waste disposal and management plans and practices for recovery of resource and energy potentials before deciding on the appropriate method of its disposal (Nilanthi et. Al., 2007, Yousuf and Rahman, 2007).

Vikash Talyan et al., (2008) have studied the present state of municipal solid waste management in the Indian capital, Delhi and concluded that only 9% of the collected MSW is treated through composting, the only treatment option, and the rest is disposed in uncontrolled open landfills at the outskirts of the city. The existing composting plants are unable to operate to their intended treatment capacity due to several operational problems. Therefore, along with residue from the composting process, the majority of MSW is disposed in the landfills without leachate and landfill gas collection. The study also summarized the proposed policies and initiatives under taken by the Government of Delhi and the Municipal Corporation of Delhi to improve the existing MSW management system.

Shekdar (2009) analyzed the situation in different Asian countries, and explored future trends and conceptually evaluated issues surrounding the sustainability of SWM. He proposed a multi-pronged integrated approach for improvement that achieves sustainable SWM in the context of national policy and legal frameworks, institutional arrangement, appropriate technology, operational and financial management, and public awareness and participation.

Syeda Adila Batool et al., (2009) studied the generation, composition, collection, transportation, and disposal as well as the present cost of the waste management at 60% collection of MSW. They have also presented the cost of the proposed improved system of management on the basis of 100% waste collection using the IWM- 2 LCI model in Lahore City District of Pakistan and estimated that 0.84/kg/cap/day of MSW is generated in the study area and only 60% of the MSW is collected and disposed in open dumps, while 40% is not collected and lies along roadsides, streets railway lines, depressions, vacant plots, drains, storm drains and open sewers.

Latifah Abid Manaf et al., (2009) have reported the generation, characteristics, and management of solid waste in Malaysia based on published information and reported that the per capita generation rate is about 0.5-0.8 kg/person/day in which domestic waste is the primary source.

Tumpa Hazra et al., (2009) have discussed the current solid waste management (SWM) practices in Kolkata, where more than 2920 ton/day of solid waste are generated in the Kolkata Municipal Corporation (KMC) area. The budget allocation for 2007-2008 was Rs.1590 million (US$40 million), which amounts to Rs.265/cap-y (US$6.7/cap-d) on SWM. This expenditure is insufficient to provide adequate SWM services. Major deficiencies were found in all the elements of SWM. Even though 70% of the SWM budget being allocated for collection, collection efficiency is around 60-70% for the registered residents and less than 20% for unregistered residents (slum dwellers). The collection process is deficient in terms of manpower and vehicles. The study also suggested solutions to some of the major problems.

A random monitoring of MSW in Puducherry, India has revealed that the solid waste of a dumping yard comprises of 65% biodegradable waste and 35% non biodegradable waste. Further analysis also indicated that the MSW consists of yard waste (38.4%) followed by paper (30%) and plastics (10.4%) and the remaining 21.2% comprised of other waste (Swati Pattnaik et al., 2010). The study has also highlighted the various methods that are adopted by the municipalities in Puducherry such as door to- door collection with segregation of garbage at the source for effective management of MSW.

2.2 Management of MSW:

2.2.1 An Overview of the Current Management Practices of MSW in India:

The MSW management in India is handled primarily by the Local governments/City Municipal Corporations as a service. The main activities include MSW collection, storage, transportation and disposal. In general, the quantity and quality of MSW generated in the metropolis are generally governed by the parameters such as population, standards of living socioeconomic conditions, commercial and industrial activities, food habits, cultural traditions and climatic conditions. The problem of MSW disposal does not entirely depend upon the efficiency of Municipal corporations. It also depends on the adaptation of suitable technologies to provide environment friendly scientific options for processing MSW that would enable generation of useful products through recycling processes and minimize the quantity of landfill disposable fraction. One such method is composting of MSW in some parts of the country. However, this it self is not a solution by itself which should be comprehensive. The efforts to mechanization were also not successful because of the very low yield of methane from mixed garbage as well as disposal problem of digester residue.

One important aspect to be taken note of in this connection is that most of the recyclable materials like papers, plastics, glass, metals are picked up by the rag pickers, thus making MSW unattractive for commercial exploitation in view of recycling. Indian garbage is known for its high moisture, soil and silt and putrifiables than the developed nations.

Rapid urbanization has led to over-stressing of urban infrastructure services including Municipal Solid Waste Management because of poor resources and inadequacies of the existing systems. Therefore, augmenting, operating & maintaining solid waste management system in a sustainable manner by urban local bodies would require huge capital investment, introduction of latest technologies which are cost effective, Public-Private Partnerships (PPP) in waste management and introduction of

appropriate waste management practices in order to prevent urban waste from causing environmental pollution and health hazards.

Per capita waste generation varies between 0.2 Kg to 0.6 Kg per day in cities with population ranging from 0.1 million to 5.0 million. An assessment on MSW revealed i) the increase in per capita waste generation is about 1.3% per year, ii) growth of urban population is between 3% and 3.5% per annum. Basing on these two variables, the yearly increase in the overall quantity of solid waste in the cities is about 5%. Waste collection efficiency ranges from 50% to 90%. Urban Local Bodies (ULB’s) spend between Rs.500/- to Rs.1500/- per ton on solid waste management, of which 60% to 70% is spent on collection alone, 20% to 30% on transportation and less than 5% on treatment and disposal which is very essential to prevent environmental pollution. In India, majority of the ULB’s resort to crude dumping of MSW as the only way of management technique without adopting scientific and hygienic approach of sanitary land filling.

Problem of urban waste management is notable in India not only because of large quantities involved, but also its spatial spread across 5161 cities and towns and enormity and variety of problems involved in setting up and managing systems for collection, transportation and disposal of waste.

2.3 Features of Indian Municipal Waste:

Urban India produces about 42.0 million tons of municipal solid waste annually i.e. 1.15 lakh metric tons per day (TPD), out of which 83,378 TPD is generated in 423 Class-I cities. Waste generated in 423 Class-I cities works out to 72.5% of the total waste generated each day and this needs to be tackled on priority basis. Municipal solid waste comprises 30% to 55% of bio-degradable (organic) matter, 40% to 55% inert matter and 5% to 15% recyclables. Composition of waste varies with size of city, season and income group.

2.4 Possible Waste Management Options:

At least 50% to 55% of municipal solid waste is also a valuable resource which can be recovered profitably using different technologies through following processing options:

2.4.1Wealth from Waste:

Organic fraction of MSW contains bio-degradable matter ranging from 30% to 55% which can be profitably converted into useful products like compost (organic manure) and methane gas (used for cooking, heating, lighting, production of energy) through the following processes:-

2.4.1 (a) Waste to Compost:

2.4.1.(a) (i) Aerobic / Anaerobic Composting:

Composting is a process of conversion of bio-degradable waste into stable mass by aerobic / anerobic decomposition producing Carbon-dioxide, Nitrogen, Phosphorous, Potassium etc. useful for soil fertility.

2.4.1.(a) (ii) Vermi-Composting:

Organic waste is stabilized through consumption by earthworms into worm castings which is known as vermi-compost and which is used as organic manure in agriculture.

2.4.1.(b) Waste to Energy:

2.4.1.(b).(i) Refuse Derived Fuel (RDF):

Pelletization involves segregation of incoming waste into high and low calorific value materials, shredding them separately to uniform size, reducing its moisture content, mixing them together and making into pellets / briquettes which are used for producing thermal energy.

2.4.1.(b).(ii) Bio-methanation:

Segregated garbage undergoes anaerobic digestion producing methane as and effluent sludge. Bio-gas production ranges from 50 M3 - 100 M3 / MT of wastes. The gas is utilized for heating applications / dual fuel engines / steam turbines for generation of power. Sludge after stabilization can be used as soil conditioner.

2.4.1.(b).(iii) Incineration:

This is a process of direct burning of wastes in the presence of excess air at temperature of about 8000C to 8700C, liberating heat energy, inert gases and ash. The process is power intensive and used for bio-medical waste management.

2.4.1.(b).(iv) Pyrolysis / Plasma Gasification:

The process of thermal decomposition of organic waste for energy recovery using plasma arc torch producing temperatures between 50000C and 140000C for heating of waste and converting into gaseous form. The process is cost-intensive and can be used for hazardous waste / bio-medical waste only .

2.4.2. Sanitary Land Filling:

MSW contains 40% to 55% of the inert matter depending upon the type of city and ongoing infrastructure development activity. This inert material cannot be converted into any useful product and needs to be managed in the scientific and hygienic manner in order to prevent pollution of underground water reservoirs or surface sources in the vicinity of the town. Therefore, the residuals / unutilized / inert materials from the waste processing facilities like compost / waste-to-energy plants are put into the scientifically engineered landfills to prevent environmental pollution.

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