A Primer on Waste-to-Energy

Waste-to-Energy is the use of modern combustion and biochemical technologies to recover energy, usually in the form of electricity and steam, from urban wastes. These new technologies can reduce the volume of the original waste by 90%, depending upon composition and use of outputs.

Energy is the driving force for development in all countries of the world. The increasing clamor for energy and satisfying it with a combination of conventional and renewable resources is a big challenge. Accompanying energy problems in different parts of the world, another problem that is assuming critical proportions is that of urban waste accumulation.

The quantity of waste produced all over the world amounted to more than 12 billion tonnes in 2006, with estimates of up to 13 billion tonnes in 2011. The rapid increase in population coupled with changing lifestyle and consumption patterns is expected to result in an exponential increase in waste generation of upto 18 billion tonnes by year 2020.

Waste generation rates are affected by socio-economic development, degree of industrialization, and climate. Generally, the greater the economic prosperity and the higher percentage of urban population, the greater the amount of solid waste produced. Reduction in the volume and mass of solid waste is a crucial issue especially in the light of limited availability of final disposal sites in many parts of the world. Millions of tonnes of household wastes are generated each year with the vast majority disposed of in open fields or burnt wantonly.

The main categories of waste-to-energy technologies are physical technologies, which process waste to make it more useful as fuel; thermal technologies, which can yield heat, fuel oil, or syngas from both organic and inorganic wastes; and biological technologies, in which bacterial fermentation is used to digest organic wastes to yield fuel.

The three principal methods of thermochemical conversion are combustion in excess air, gasification in reduced air, and pyrolysis in the absence of air. The most common technique for producing both heat and electrical energy from wastes is direct combustion. Combined heat and power (CHP) or cogeneration systems, ranging from small-scale technology to large grid-connected facilities, provide significantly higher efficiencies than systems that only generate electricity.

Biochemical processes, like anaerobic digestion, can also produce clean energy in the form of biogas which can be converted to power and heat using a gas engine. In addition, wastes can also yield liquid fuels, such as cellulosic ethanol, which can be used to replace petroleum-based fuels. Cellulosic ethanol can be produced from grasses, wood chips and agricultural residues by biochemical route using heat, pressure, chemicals and enzymes to unlock the sugars in biomass wastes.

Waste-to-energy plants offer two important benefits of environmentally safe waste management and disposal, as well as the generation of clean electric power.  The growing use of waste-to-energy as a method to dispose of solid and liquid wastes and generate power has greatly reduced environmental impacts of municipal solid waste management, including emissions of greenhouse gases.

Recycling Outlook for Latin America

Latin America has one of the highest rates of urbanization in the world (80% urban population). By 2050, 90% of Latin America’s population will live in urban areas. This high rate of urbanization coupled with the global economic crisis has resulted in a waste management crisis. Municipalities find themselves unable to keep up with providing services and infrastructure to the urban populations.

Some cities in Latin America are facing this challenge by integrating the informal sector recyclers who are already active in their cities into the municipal solid waste management systems. In many cities, these “recicladores”, “cartoneros” or “catadores” (a few of the many names used for these workers in the region) are responsible for up to 90% of the recyclable waste recovered from the waste stream. Their work reduces municipal waste transportation costs, increases landfill lifetimes and supports the recycling chain throughout the region.

State of the Affairs

Every location presents its own challenges–there is no one-size-fits-all solution for integrated solid waste management systems–but relevant lessons can be drawn from both failed attempts and successful examples of informal sector integration in recycling systems in Latin America.

There are often two very different contexts within cities. In low-income neighborhoods waste collection services are often not provided and individuals and families accumulate and then sell their recyclables for additional income. In contrast, residents in high income neighborhoods do receive a waste collection service and their motivation for recycling is often related to greater levels of environmental awareness. It is important to consider these differences when designing waste management solutions.

Imported systems, and even locally derived systems based on examples from the Global North, generally focus on only one waste management scenario, making it difficult to manage the multiple competing scenarios in many cities in Latin America. There is often a bias towards the automation of waste management services, with the application of the high technology solutions used in the Global North. Regardless of the practicality or scientific evidence against certain high tech solutions, these are often sought after, thought to raise the bar of the city, to make it appear more sophisticated and modern. This leads to a misconception that working with informal sector is a step backwards in terms of urban development and modernization.

Conflicts between private waste management companies, the municipality and informal recyclers are common. The waste management companies do not want pickers on the landfill and wastepickers then go to the municipality for help. However, municipalities usually have very little experience to support the integration of formal and informal waste sectors. There are opportunities for new systems to emerge within this conflict. For example, during a similar conflict in Mexicali, Mundo Sustentable, with the help of Danone, intervened to help a private company work with the informal waste sector and improve recycling rates.

The Way Forward

In Latin America, there is a great opportunity to increase recycling rates by using labour-intensive solutions, which create jobs and support the development of a better urban environment in the cities. Municipal governments should be an integral part of these processes as they are usually responsible for solid waste management at local level. The key to catalyzing informal recycling sector integration will be the development and dissemination of successful examples.

Informal recyclers provide important a range of services to municipalities (such as waste collection and recovery in communities that would not otherwise have access to them), as well as cost savings (for example, the extension of landfill life and reduced transport costs), yet are rarely compensated for these benefits. Informal recyclers further form the foundation of an entire recycling supply chain, which ultimately benefits formal businesses, and often aliment entire local economies.

Challenges to Overcome

Municipal governments are often hesitant to work with informal actors, who are frequently seen as an unknown quantity. Yet often in the process of working and developing relations with informal recycler groups, their concerns diminish and they may actually exhibit enthusiasm. Likewise, the recyclers may gain in confidence and professionalism in their experience of formalization.

One major challenge facing efforts to integrate the informal sector in developing countries is the desire of some local governments to adopt technological solutions that appear more “modern.” In much of Latin America, however, low-cost, low-tech solutions tend to be more viable and sustainable.

The main difference between Latin America and the countries of the Global North is that solid waste management is a labor intensive system. It is made up of workers and hence has an important social component. The ILO estimated there is 24 million of people working in the global recycling supply chain, but those at the bottom of the pyramid, the wastepickers, make up 80%. They remain the lowest paid even though they make an enormous contribution to their cities.

It is important to understand that highly sophisticated, high technology systems are not required for effective resource recovery. In many cities in Latin America between 80-90% of everything that is recycled is recovered by the informal recycling sector.

Despite the fact that there is little or no public investment in waste management or recycling infrastructure, cities with an active informal sector reach twice the rate of fully formalized municipal solid waste management systems. As an example, the recycling rate is 60% in Cairo, while in Rotterdam (and other cities in the Global North) recycling levels only reach 30%, even with a high public investment in the system (UN Habitat, 2010).

When designing infrastructure and waste management systems we must consider not only the waste management and resource recovery needs but also the social side of the system. In order to be effective, efforts to upgrade waste management services should go hand in hand with efforts to formalise and integrate the informal sector.

Bogota – A Success Story

An example of a recent success story is that after 27 years of struggle, the waste pickers in Bogota, Colombia have managed to change the government’s outlook on their work and their existence. They are now included in the system and are paid per tonne of waste collected, just like any other private sector collection and waste management company would be. They have become recognized as public service providers, acknowledged for their contribution to the environment and public health of the city.

The key challenge is to be much more creative and understand that in order to improve the working conditions of waste pickers and in order to increase recycling rates, we don’t need high technology. We need a systemic approach and this can be very simple sometimes infrastructure as simple as a roof [on a sorting area] can be effective in improving working conditions.

Note: This excerpt is being published with the permission of our collaborative partner Be Waste Wise. The original excerpt and its video recording can be found at this link

Municipal Wastes in Saudi Arabia

Saudi Arabia has been witnessing rapid industrialization, high population growth rate and fast urbanization which have resulted in increased levels of pollution and waste. Solid waste management is becoming a big challenge for the government and local bodies with each passing day. With population of around 29 million, Saudi Arabia generates more than 15 million tons of solid waste per year. The per capita waste generation is estimated at 1.5 to 1.8 kg per person per day.

Solid waste generation in the three largest cities – Riyadh, Jeddah and Dammam – exceeds 6 million tons per annum which gives an indication of the magnitude of the problem faced by civic bodies.  More than 75 percent of the population is concentrated in urban areas which make it necessary for the government to initiate measures to improve recycling and waste management scenario in the country.

In Saudi Arabia, municipal solid waste is collected from individual or community bins and disposed of in landfills or dumpsites. Saudi waste management system is characterized by lack of waste disposal and tipping fees. Recycling, reuse and energy recovery is still at an early stage, although they are getting increased attention. Waste sorting and recycling are driven by an active informal sector. Recycling rate ranges from 10-15%, mainly due to the presence of the informal sector which extracts paper, metals and plastics from municipal waste.

Recycling activities are mostly manual and labor intensive. Composting is also gaining increased interest in Saudi Arabia due to the high organic content of MSW (around 40%).  Efforts are also underway to deploy waste-to-energy technologies in the Kingdom. All activities related to waste management are coordinated and financed by the government.

The Saudi government is aware of the critical demand for waste management solutions, and is investing heavily in solving this problem. The 2011 national budget allocated SR 29 billion for the municipal services sector, which includes water drainage and waste disposal. The Saudi government is making concerted efforts to improve recycling and waste disposal activities.

Waste Management Scenario in Oman

Waste management is a challenging issue for the Sultanate of Oman due to high waste generation rates and scarcity of disposal sites. With population of almost 3 million inhabitants, the country produced about 1.6 million tons of solid waste in 2010. The per capita waste generation is more than 1.5 kg per day, among the highest worldwide.

Solid waste in Oman is characterized by very high percentage of recyclables, primarily paper (26%), plastics (12%), metals (11%) and glass (5%). However the country is yet to realize the recycling potential of its municipal waste stream. Most of the solid waste is sent to authorized and unauthorized dumpsites for disposal which is creating environment and health issues. There are several dumpsites which are located in the midst of residential areas or close to catchment areas of private and public drinking water bodies.

Solid waste management scenario in marked by lack of collection and disposal facilities. Solid waste, industrial waste, e-wastes etc are deposited in very large number of landfills scattered across the country. Oman has around 350 landfills/dumpsites which are managed by municipalities. In addition, there are numerous unauthorized dumpsites in Oman where all sorts of wastes are recklessly dumped.

Al Amerat landfill is the first engineered sanitary landfill in Oman which began its operations in early 2011. The landfill site, spread over an area of 9.6 hectares, consists of 5 cells with a total capacity of 10 million m3 of solid waste and spread over an area of over 9.6 hectares. Each cell has 16 shafts to take care of leachate (contaminated wastewater). All the shafts are interconnected, and will help in moving leachate to the leachate pump. The project is part of the government’s initiatives to tackle solid waste in a scientific and environment-friendly manner. Being the first of its kind, Al Amerat sanitary landfill is expected to be an example for the future solid waste management projects in the country.

Solid waste management is among the top priorities of Oman government which has chalked out a robust strategy to resolve waste management problem in the Sultanate. The country is striving to establish engineered landfills, waste transfer stations, recycling projects and waste-to-energy facilities in different parts of the country.  Modern solid waste management facilities are under planning in several wilayat, especially Muscat and Salalah. The new landfills will eventually pave the way for closure of authorized and unauthorized garbage dumps around the country. However investments totaling Omani Rial 2.5 billion are required to put this waste management strategy into place.

The state-owned Oman Environment Services Holding Company (OESHCO), which is responsible for waste management projects in Oman, has recently started the tendering process for eight important projects. OESHCO has invited tenders from specialised companies for an engineered landfill and material recovery facility in Barka, apart from advisory services for 29 transfer stations and a couple of tenders for waste management services in the upcoming Special Economic Zone (SEZ) in Duqm, among others. Among the top priorities is that development of Barka engineered landfill as the existing Barka waste disposal site, which serve entire wilayat and other neighbouring wilayats in south Batinah governorate, is plagued by environmental and public health issues.

Waste Management in Qatar

Waste management is one of the most serious environmental challenges faced by the tiny Gulf nation of Qatar. mainly on account of high population growth rate, urbanization, industrial growth and economic expansion. The country has one of the highest per capita waste generation rates worldwide of 1.8 kg per day. Qatar produces more than 2.5 million tons of municipal solid waste each year. Solid waste stream is mainly comprised of organic materials (around 60 percent) while the rest of the waste steam is made up of recyclables like glass, paper, metals and plastics.

Municipalities are responsible for solid waste collection in Qatar both directly, using their own logistics, and indirectly through private sector contract. Waste collection and transport is carried out by a large fleet of trucks that collect MSW from thousands of collection points scattered across the country.

The predominant method of solid waste disposal is landfilling. The collected is discharged at various transfer stations from where it is sent to the landfill. There are three landfills in Qatar; Umm Al-Afai for bulky and domestic waste, Rawda Rashed for construction and demolition waste, and Al-Krana for sewage wastes. However, the method of waste disposal by landfill is not a practical solution for a country like Qatar where land availability is limited.

Solid Waste Management Strategy

According to Qatar National Development Strategy 2011-2016, the country will adopt a multi-faceted strategy to contain the levels of waste generated by households, commercial sites and industry – and to promote recycling initiatives. Qatar intends to adopt integrated waste hierarchy of prevention, reduction, reuse, recycling, energy recovery, and as a last option, landfill disposal.

A comprehensive solid waste management plan is being implemented which will coordinate responsibilities, activities and planning for managing wastes from households, industry and commercial establishments, and construction industry. The target is to recycle 38 percent of solid waste, up from the current 8 percent, and reduce domestic per capita waste generation.

Five waste transfer stations have been setup in South Doha, West Doha, Industrial Area, Dukhan and Al-Khor to reduce the quantity of waste going to Umm Al-Afai landfill. These transfer stations are equipped with material recovery facility for separating recyclables such as glass, paper, aluminium and plastic.

Domestic Solid Waste Management Centre

One of the most promising developments has been the creation of Domestic Solid Waste Management Centre (DSWMC) at Mesaieed. This centre is designed to maximize recovery of resources and energy from waste by installing state-of-the-art technologies for separation, pre-processing, mechanical and organic recycling, and waste-to-energy and composting technologies. At its full capacity, it will treat 1550 tons of waste per day, and is expected to generate enough power for in-house requirements, and supply a surplus of 34.4 MW to the national grid.

Future Outlook

While commendable steps are being undertaken to handle solid waste, the Government should also strive to enforce strict waste management legislation and create mass awareness about 4Rs of waste management viz. Reduce, Reuse, Recycle and Recovery. Legislations are necessary to ensure compliance, failure of which will attract a penalty with spot checks by the Government body entrusted with its implementation.

Improvement in curbside collection mechanism and establishment of material recovery facilities and recycling centres may also encourage public participation in waste management initiatives. When the Qatar National Development Strategy 2011-2016 was conceived, the solid waste management facility plant at Mesaieed was a laudable solution, but its capacity has been overwhelmed by the time the project was completed. Qatar needs a handful of such centers to tackle the burgeoning garbage disposal problem.

Solid Waste Management in Nigeria

waste-nigeriaSolid waste management is the most pressing environmental challenge faced by urban and rural areas of Nigeria. Nigeria, with population exceeding 170 million, is one of the largest producers of solid waste in Africa. Despite a host of policies and regulations, solid waste management in the country is assuming alarming proportions with each passing day.

Nigeria generates more than 32 million tons of solid waste annually, out of which only 20-30% is collected. Reckless disposal of MSW has led to blockage of sewers and drainage networks, and choking of water bodies. Most of the wastes is generated by households and in some cases, by local industries, artisans and traders which litters the immediate surroundings. Improper collection and disposal of municipal wastes is leading to an environmental catastrophe as the country currently lack adequate budgetary provisions for the implementation of integrated waste management programmes across the States.

According to the United Nations Habitat Watch, African city populations will more than triple over the next 40 years. African cities are already inundated with slums; a phenomenon that could triple urban populations and spell disaster, unless urgent actions are initiated. Out of the 36 states and a federal capital in the country, only a few have shown a considerable level of resolve to take proactive steps in fighting this scourge, while the rest have merely paid lip services to issues of waste management indicating a huge lack of interest to develop the waste sector.

Scenario in Lagos

Lagos State, the commercial hub of Nigeria, is the second fastest growing city in Africa and seventh in the world.  The latest reports estimate its population to be more than 21 million making it the largest city in entire Africa.  With per capita waste generation of 0.5 kg per day, the city generates more than 10,000 tons of urban waste every day.

Despite being a model for other states in the country, municipal waste management is a big challenge for the Lagos State Waste Management Agency (LAWMA) to manage alone, hence the need to engage the services of private waste firms and other franchisee to reduce the burden of waste collection and disposal. One fundamental issue is the delayed collection of household solid waste.  In some cases, the wastes are not collected until after a week or two, consequently, the waste bin overflows and litters the surroundings.

Improper waste disposal and lack of reliable transport infrastructure means that collected wastes are soon dispersed to other localities. Another unwelcome practice is to overload collection trucks with 5-6 tons of waste to reduce the number of trips; this has necessitated calls by environmental activist to prevail on the relevant legislature to conform to the modern waste transportation standard.

Situation in Oyo

Away from Lagos State, Oyo is another ancient town in Nigeria with an estimated population of six million people. Here, solid waste is regulated by the Oyo State Solid Waste Management Authority (OYOWMA). Unlike Lagos State, Oyo State does not have a proper waste management scheme that cuts across the nooks and crannies of the state, apart from Ibadan, the capital city, people from other towns like Ogbomoso and Iseyin resort to waste burning. In case the waste generators feels that the amount being charged by the waste franchisee is beyond their means, they dump the waste along flood paths thus compounding the waste predicament.

Burning of municipal wastes is a common practice in Nigeria

Burning of municipal wastes is a common practice in Nigeria

Kano and Rivers State with its fair share of population also suffers similar fate in controlling and managing solid waste. Generally speaking, population increase in Nigeria has led to an unprecedented growth in its economy but with a devastating effect on the environment as more wastes are generated due to the need for housing, manufacturing industries and a boost in trade volume.

Future Perspectives

The government at the federal level as a matter of urgency needs to revive its regulatory framework that will be attractive for private sectors to invest in waste collection, recycling and reusing.  The environmental health officer’s registration council of Nigeria would do well to intensify more effort to monitor and enforce sanitation laws as well as regulate the activities of the franchisees on good sustainable practices.

Taking the advocacy further on waste management, to avoid littering the environment, some manufacturing companies (e.g. chemical and paint industry) have introduced a recall process that will reward individuals who returns empty/used plastic containers. This cash incentive has been proven over time to validate the waste to wealth program embarked upon by the manufacturing companies. It is also expected that the government will build more composting and recycling plants in addition to the ones in Ekiti and Kano State to ensure good sustainable waste management.

Waste management situation in Nigeria currently requires concerted effort to sensitize the general public on the need for proper disposal of solid waste. Also, the officials should be well trained on professionalism, service delivery and ensure that other states within the country have access to quality waste managers who are within reach and can assist on the best approach to managing their waste before collection.

Rationale for Solid Waste Management

Some countries have achieved considerable success in solid waste management. But the rest of the world is grappling to deal with its wastes. In these places, improper management of solid waste continues to impact public health of entire communities and cities; pollute local water, air and land resources; contribute to climate change and ocean plastic pollution; hinder climate change adaptation; and accelerate depletion of forests and mines.

Compared to solid waste management, we can consider that the world has achieved significant success in providing other basic necessities like food, drinking water, energy and economic opportunities. Managing solid wastes properly can help improve the above services further. Composting organic waste can help nurture crops and result in a better agricultural yield. Reducing landfilling and building sanitary landfills will reduce ground and surface water pollution which can help provide cleaner drinking water. Energy recovery from non-recyclable wastes can satiate significant portion of a city’s energy requirement.

Inclusive waste management where informal waste recyclers are involved can provide an enormous economic opportunity to the marginalized urban poor. Additionally, a good solid waste management plan with cost recovery mechanisms can free tax payers money for other issues. In the case of India, sustainable solid waste management in 2011 would have provided

  • 9.6 million tons of compost that could have resulted in a better agricultural yield
  • energy equivalent to 58 million barrels of oil from non-recyclable wastes
  • 6.7 million tons of secondary raw materials to industries in the form of recyclable materials and livelihood to the urban poor

Solid waste management until now has only been a social responsibility of the corporate world or one of the services to be provided by the municipality and a non-priority for national governments. However, in Mumbai, the improperly managed wastes generate 22,000 tons of toxic pollutants like particulate matter, carbon monoxide, nitrous and sulfur oxides in addition to 10,000 grams of carcinogenic dioxins and furans every year. These numbers are only for the city of Mumbai. This is the case in cities all across the developing world. There are numerous examples where groundwater is polluted by heavy metals and organic contaminants due to solid waste landfills.

Solid waste management expenditure of above $ 1 billion per year competes with education, poverty, security and other sustainable initiatives in New York City. Fossil fuels for above 500,000 truck trips covering hundreds of miles are required to transport NYC’s waste to landfills outside the city and state. Similarly, New Delhi spends more than half of its entire municipal budget on solid waste management, while it is desperate for investments and maintenance of roads, buildings, and other infrastructure.

Solid waste management is not just a corporate social responsibility or a non-priority service anymore. Improper waste management is a public health and environmental crisis, economic loss, operational inefficiency and political and public awareness failure. Integrated solid waste management can be a nation building exercise for healthier and wealthier communities. Therefore, it needs global attention to arrive at solutions which span across such a wide range of issues.

Municipal Solid Wastes in Bahrain

The Kingdom of Bahrain is an archipelago of around 33 islands, the largest being the Bahrain Island. The population of Bahrain is around 1.2 million marked by population density of 900 persons per km2, which is the highest in the entire GCC region. The country has the distinction of being one of the highest per capita municipal solid waste generators worldwide estimated to be 1.67 – 1.80 kg per person per day. Infact, Bahrain produces largest amount of waste per person among GCC countries despite being the smallest nation in the region. Rising population, high waste generation growth rate, limited land availability and scarcity of waste disposal sites has made solid waste management a highly challenging task for Bahrain’s policy-makers, urban planners and municipalities.

Municipal Solid Wastes in Bahrain

Bahrain generates more than 1.2 million tons of solid wastes every year. Daily garbage production across the tiny Gulf nation exceeds 4,500 tons. Municipal solid waste is characterized by high percentage of organic material (around 60 percent) which is mainly composed of food wastes. Presence of high percent of recyclables in the form of paper (13 percent), plastics (7 percent) and glass (4 percent) makes Bahrain’s MSW a good recycling feedstock, though informal sectors are currently responsible for collection of collection of recyclables and recycling activities

The Kingdom of Bahrain is divided into five governorates namely Manama, Muharraq, Middle, Southern and Northern. Waste collection and disposal operation in Bahrain is managed by a couple of private contractors. Gulf City Cleaning Company is active in Muharraq and Manama while Sphinx Services is responsible for Southern, Middle, and Northern Areas. The prevalent solid waste management scenario is to collect solid waste and dump it at the municipal landfill site at Askar.

Askar, the only existing landfill/dumpsite in Bahrain, caters to municipal wastes, agricultural wastes and non-hazardous industrial wastes. Spread over an area of more than 700 acres, the landfill is expected to reach its capacity within the next few years. The proximity of Askar landfill to urban habitats has been a cause of major environmental concern. Waste accumulation is increasing at a rapid pace which is bound to have serious impacts on air, soil and groundwater quality in the surrounding areas.

Conclusions

The Kingdom of Bahrain is grappling with waste management problems arising out of high population growth rate, rapid industrialization, high per capita waste generation, unorganized SWM sector, limited land resources and poor public awareness. The government is trying hard to improve waste management scenario by launching recycling initiatives, waste-to-energy project and public awareness campaign. However more efforts, in the form of effective legislation, large-scale investments, modern SWM technology deployment and environmental awareness, are required from all stake holders to implement a sustainable waste management system in Bahrain.

Solid Waste Management – India’s Burning Issue

For the first time in the history of India, the year 2012 saw several public protests against improper solid waste management all across India – from the northernmost state Jammu and Kashmir to the southernmost Tamil Nadu. A fight for the right to clean environment and environmental justice led the people to large scale demonstrations, including an indefinite hunger strike and blocking roads leading to local waste handling facilities. Improper waste management has also caused a Dengue Fever outbreak and threatens other epidemics. In recent years, waste management has been the only other unifying factor leading to public demonstrations all across India, after corruption and fuel prices. Public agitation resulted in some judicial action and the government’s remedial response, but the waste management problems are still unsolved and might lead to a crisis if this continues for too long without any long term planning and policy reforms.

Hunger Strike in Kerala

The President of Vilappilsala Village Panchayat went on a hunger strike recently, against her counterpart, the Mayor of Thiruvananthapuram. Thiruvananthapuram is the state capital of Kerala, and Vilappilsala is a village 22 km away. Since July 2000, about 80% of the waste generated in Thiruvananthapuram is being transported to a waste composting plant and a dumpsite in Vilappilsala village. Since the same month, respiratory illnesses reported in Vilappil Primary Health Center increased by 10 times from an average of 450 to 5,000 cases per month. People who used to regularly swim in the village’s aquifer started contracting infections; swarms of flies have ever since been pervasive; and a stigma of filth affected households throughout the community. This was a source of frustration as locals who, as Indians, prize the opportunity to feed and host guests, found them unwilling to even drink a glass of water in their homes. Currently, there is not a single household which has not experienced respiratory illnesses due to the waste processing plant and the adjoining dumpsite.

On the other hand, Thiruvananthapuram’s residents had to sneak out at night with plastic bags full of trash to dispose them behind bushes, on streets or in water bodies, and had to openly burn heaps of trash every morning for months. This was because the waste generated was not being collected by the City as it could not force open the composting plant and dumpsite against large scale protests by Vilappilsala’s residents. This is why in August – 2012, about 2,500 police personnel had to accompany trucks to the waste treatment plant as they were being blocked by local residents lying down on the road, and by some, including the village’s President, by going on an indefinite hunger strike.

Municipal Commissioner Replaced in Karnataka

In response to a similar situation in Bengaluru, the state capital of Karnataka, where the streets were rotting with piles of garbage for months, the municipal commissioner of the city was replaced to specifically address the waste management situation. Against the will of local residents, a landfill which was closed following the orders issued by the state’s pollution control board in response to public agitation had to be reopened soon after its closure as the city could not find a new landfill site.

Mavallipura landfill in Bangalore

Population density and the scale of increasing urban sprawl in India make finding new landfill sites around cities nearly impossible due to the sheer lack of space for Locally Unwanted Land Uses (LULUs) like waste management.

Dengue Outbreak in West Bengal

Even if partially because of improper waste management, Kolkata, state capital of West Bengal and the third biggest city in India experienced a Dengue Fever outbreak with 550 confirmed cases and 60 deaths. This outbreak coincides with a 600% increase in dengue cases in India and 71% increase in malarial cases in Mumbai in the last five years. Accumulation of rain water in non biodegradable waste littered around a city act as a major breeding environment for mosquitoes, thus increasing the density of mosquito population and making the transmission of mosquito related diseases like dengue, yellow fever and malaria easier.

Rabies in Srinagar

Rabies due to stray dog bites already kills more than 20,000 people in India every year. Improper waste management has caused a 1:13 stray dog to human ratio in Srinagar (compared to 1 per 31 people in Mumbai and 1 per 100 in Chennai), where 54,000 people were bitten by stray dogs in a span of 3.5 years. Municipal waste on streets and at the dumpsite is an important source of food for stray dogs. The ultimate solution to controlling stray dogs is proper waste management. The public has been protesting about this stray dog menace for months now with no waste management solutions in sight, but only partial short term measures like dog sterilization.

MSW to Energy at a Glance

MSW-to-Energy is the use of thermochemical and biochemical technologies to recover energy, usually in the form of electricity and steam, from urban wastes. These new technologies can reduce the volume of the original waste by 90%, depending upon composition and use of outputs. The main categories of MSW-to-energy technologies are physical technologies, which process waste to make it more useful as fuel; thermal technologies, which can yield heat, fuel oil, or syngas from both organic and inorganic wastes; and biological technologies, in which bacterial fermentation is used to digest organic wastes to yield fuel.

Components of MSW-to-Energy Systems

  1. Front-end MSW preprocessing
  2. Conversion unit (reactor or anaerobic digester)
  3. Gas cleanup and residue treatment plant
  4. Energy recovery plant (optional)
  5. Emissions clean up

Incineration

  • Combustion of raw MSW, moisture less than 50%
  • Sufficient amount of oxygen is required to fully oxidize the fuel
  • Combustion temperatures are in excess of 850oC
  • Waste is converted into CO2 and water concern about toxics (dioxin, furans)
  • Any non-combustible materials (inorganic such as metals, glass) remain as a solid, known as bottom ash (used as feedstock in cement and brick manufacturing)
  • Fly ash APC (air pollution control residue) particulates, etc
  • Needs high calorific value waste to keep combustion process going, otherwise requires high energy for maintaining high temperatures

Anaerobic Digestion

  •  Well-known biochemical technology for organic fraction of MSW and domestic sewage.
  • Biological conversion of biodegradable organic materials in the absence of oxygen at mesophilic or thermophilic temperatures.
  • Residue is stabilized organic matter that can be used as soil amendment
  • Digestion is used primarily to reduce quantity of sludge for disposal / reuse
  • Methane gas is generated which is used for heat and power generation.

Gasification

  • Can be seen as between pyrolysis and combustion (incineration) as it involves partial oxidation.
  • Exothermic process (some heat is required to initialize and sustain the gasification process).
  • Oxygen is added but at low amounts not sufficient for full oxidation and full combustion.
  • Temperatures are above 650oC
  • Main product is syngas, typically has net calorific value of 4 to 10 MJ/Nm3
  • Other product is solid residue of non-combustible materials (ash) which contains low level of carbon

Pyrolysis

  • Thermal degradation of organic materials through use of indirect, external source of heat
  • Temperatures between 300 to 850oC are maintained for several seconds in the absence of oxygen.
  • Product is char, oil and syngas composed primarily of O2, CO, CO2, CH4 and complex hydrocarbons.
  • Syngas can be utilized for energy production or proportions can be condensed to produce oils and waxes
  • Syngas typically has net calorific value (NCV) of 10 to 20 MJ/Nm

Plasma Gasification

  • Use of electricity passed through graphite or carbon electrodes, with steam and/or oxygen / air injection to produce electrically conducting gas (plasma)
  • Temperatures are above 3000oC
  • Organic materials are converted to syngas composed of H2, CO
  • Inorganic materials are converted to solid slag
  • Syngas can be utilized for energy production or proportions can be condensed to produce oils and waxes
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MSW-to-energy technologies can address a host of environmental issues, such as land use and pollution from landfills, and increasing reliance on fossil fuels. In many countries, the availability of landfill capacity has been steadily decreasing due to regulatory, planning and environmental permitting constraints. As a result, new approaches to waste management are rapidly being written into public and institutional policies at local, regional and national levels.