The disposal of municipal solid waste is the second most major concern for public health in developing countries because of population explosion, rampant poverty and high urbanization rates combined with poor government funding to curb waste management. Factors such as waste composition, technologies and lack of infrastructure have been found to set apart the good management of solid wastes in developing nations. Municipal waste is mainly comprised of paper, vegetable matter, plastics, metals, textiles, rubber and glass. In some countries (developing as well as developed), municipal solid waste is mixed with medical wastes and this may pose health risk to waste handlers and general public.
Historically, burying the wastes is the most preferred method for waste management in many countries. This method is still used in many more countries. Tackling environmental issues has become more important and more preferred than pollution and consumption of unsustainable utilization of resources. Most importantly, the primary objective of waste management is to put emphasis on protecting the people and environment from potentially harmful effects of waste.
Methods of Solid Waste Management
Depending on the types of wastes generated, four methods of solid waste management has been used throughout the history, i.e. dumping, incineration, recycling and waste prevention. Waste generated from household is much different from industrial waste, agricultural waste, medical waste or mining wastes.
When wastes contain any hazardous component, or it has capability to become hazardous with time, poses very serious threat to environment and health. Hazardous wastes generated needs to be handled very carefully, with special techniques. This is one of the major reasons of open landfills are getting replaced with sanitary landfills.
At a landfill, wastes are covered with thick layer of soil. By the late 1950, this practice was very common for waste management across the world. Earlier landfills had considerable sludge and methane emissions, which were harmful to the environment as well as animal and human health. But these issues have been resolved largely by modern disposal methods, which were developed around 20 years ago. Modern landfills are equipped with thick layer of clay followed by plastic sheets. This method was practiced by some nations and still going on.
In 1930-1940, many cities in USA adopted new technology to curb waste issues by burning at high temperature, this method is known as incineration. During initial years, this method was not very efficient and emit very large amount of poisonous gasses, this is the major reason of incinerators shut down during that period. During mid-1970s, scientists modified incinerators to generate energy, which are known as waste to energy plants. But after around a decade, it has become major issue to build these plants, again because of emission issues.
With development of technology, waste burning in advanced form of incinerators became common in 1970s, researchers across the world bet on incinerators or waste to energy plants for solution to energy crisis in 1973. However, with realisation of impact on environment and air quality, it become very difficult to find location to build any waste to energy plants, mainly because of public opposition. Another issue with incinerator is production of ashes, which contain huge amount of heavy metals, toxic and inorganic compounds.
Incineration is the most common waste-to-energy method used worldwide.
Future of Solid Waste Management
The overall concept of wastes needs to be considered economically, it will be more considered as economically viable product if waste is considered as an inefficiency of the production process not as rejected residue of waste product. A permanent rejection or heavy restriction into products which produces waste that cannot be accumulated back into the environment safely.
The major challenge in waste management is to persuade people/community to consider waste as a resource, rather than a liability on society, which can be created with more innovation and technological development of manufacturing industry, waste processing industry and new business model and plans.
This planning system will create circular economy where product value created by inputs (e.g. energy, materials, labour etc.) is extended by enabling a material that goes into circular economy, beyond product life. We go from mineral to metals to product then back to minerals/metals. By understanding economic cycle of waste, people will understand the creation of opportunities to more sustainable product in future with limited resources.
The biggest challenge in the implementation of Waste-to-Energy projects lies not in the technology itself but in the acceptance of citizens. Citizens who are environmentally minded but lack awareness of the current status of MSW-to-energy bring up concerns of environmental justice and organize around this. They view waste-to-energy as ‘dumping’ of pollutants on lower strata of society and their emotional critique rooted in the hope for environmental justice tends to move democracy.
An advocate of public understanding of science, Shawn Lawrence Otto regrets that the facts are not able to hold the same sway. Some US liberal groups such as the Center for American Progress are beginning to realize that the times and science have changed. It will take more consensus on the science and the go ahead from environmental groups before the conversation moves forward, seemingly improbable but not without precedent.
Spittelau Waste-to-Energy Plant
The Spittelau waste-to-energy plant is an example of opposition coming together in consensus over WTE. It was built in Vienna in 1971 with the purpose of addressing district heating and waste management issues. Much later awareness of the risks of dioxins emitted by such plants grew and the people’s faith in the technology was called into question.
It also became a political issue whereby opposition parties challenged the mayor on the suitability of the plant. The economic interests of landfill owners also lay in the shutting down of the WTE facility. The alternative was to retrofit the same plant with advanced technology that would remove the dioxins through Selective Catalytic Reduction (SCR).
Through public discussions it appeared that the majority of the people were against the plant altogether though thorough studies by informed researchers showed that the science backs WTE. The mayor, Helmut Zilk eventually consulted Green Party members on how to make this technology better perceived in the eyes of the people, and asked the famous Austrian artist Freidensreich Hundertwasser, who was a green party member to design the look of the plant.
Freidensreich Hundertwasser after carefully studying the subject wrote a letter of support, stating his belief as to why WTE was needed and accepted Mayor Helmut Zilk’s request. Later public opinion polls showed that there were a majority of people who were either in favor of or not opinionated about the plant, with only 3% in outright opposition of the plant.
Waste-to-Energy or recycling has kept public discourse from questioning whether there may not be intermediate or case specific solutions. This polarization serves to move the conversation nowhere. For now it can be agreed that landfills are devastating in their contribution to Climate Change and must be done away with.
Environmental implications (i.e. CO2 emissions vis-à-vis the next best fuel source) given the composition of the local waste stream. If the waste stream consists of a high percentage of recyclables the more sustainable waste strategy would be to ramp up recycling efforts rather than to adopt WTE,
Likely composition and variation of the waste stream and the feasibility of the technology to handle such a waste stream,
Financial considerations with regards to the revenue stream from the WTE facility and its long term viability,
Efforts at making citizens aware of the high standards achieved by this technology in order to secure their approval.
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
Construction is booming worldwide driven by population growth, urbanization and increased need for dwellings, business sites and commercial spaces with volume output expected to grow by 85% to $15.5 trillion by 2030. Unfortunately, it also means that there is a serious challenge to implement sustainable waste management in the construction industry.
It is not only the duty of waste management contractors and companies to ensure sustainable collection and management of construction wastes responsibly but also individuals who are doing their own DIY projects at home. Without a concerted effort to collect, recycle and dispose waste properly, there is real danger to the environment that will eventually spill over to people, vegetation, and wildlife.
Role of education and behavior change
On a global scale, over half of the world’s population have no access to a steady collection of trash. Illegal dumpsites hold over 40% of the world’s waste. It’s not only the lack of facilities but also inadequate information that is contributing to waste-related pollution all over the world.
Sustainable waste collection begins by educating people about reducing, reusing and recycling efforts or the 3R approach. From education and information campaigns to changes in behavior and attitudes, when people know and are aware of the benefits of reducing, segregating, collection, reusing and recycling, they become a collective and conscious effort.
Right materials and equipment
The availability of skips, bins, collection containers, and recycling centers also has a great influence on how much a person and their communities recycle and reuse or dispose of construction waste properly. For people who are able to hire a 20 yard dumpster in West Chester, Lancaster, Norrington, Reading or any other town in the world, it is easier and convenient to remove construction and renovation waste knowing that the company will dispose of it properly by bringing it to approved landfills.
General awareness to reduce dumping is increasing as about 35% of construction and demolition waste (CDW) goes to landfills. Construction rubbish can contain lots of toxic materials such as lead, asbestos, and other dangerous substances that can find their way into the soil, groundwater, and the air that we breathe.
The construction industry has also recognized that reusing components and materials in making or erecting structures is sustainable and saves money. Most of the parts of construction consist of wood, sticks, steel, and concrete. Rubble can be compacted and reused. Demolition is carefully considered if renovation can be carried out.
The Way Forward
Waste generated from construction sites need not be a nuisance to the environment. With the right education to increase awareness to reduce/recycle/reuse, provision of collection and recycling points and the newer and better techniques to reuse construction materials, sustainable management of construction waste can become a reality.
Urban waste management has emerged as a big challenge for the government and local bodies in Saudi Arabia. The country generates more than 15 million tons of municipal solid waste each year with per capita waste production estimated to be 2 kg per day, among the highest worldwide. Municipal waste production in three largest cities – Riyadh, Jeddah and Dammam – exceeds 6 million tons per annum which gives an indication of the enormity of the problem faced by civic bodies.
The Problem of Waste
Municipal waste generation in Saudi Arabia is increasing at an unprecedented rate. Due to high population growth rate, rapid urbanization and fast-paced economic development, MSW generation is expected to cross 30 million tons per year by 2033. More than 75 percent of Kingdom’s population is concentrated in urban areas, and collected garbage is thrown in landfills or dumpsites without any processing or treatment.
Most of the landfills in Saudi Arabia are non-sanitary and prone to problems like leachate, vermin, flies and spontaneous fires, apart from greenhouse gas emissions. It has become necessary for the Saudi government to devise an integrated waste management strategy, using international best practices and modern technologies, to tackle heaps of garbage accumulating across the country.
Promise of Waste-to-Energy
Waste-to-energy provides a cost-effective and eco-friendly solution to both energy demand and MSW disposal problems in Saudi Arabia. Increasing waste generation, inability of existing solutions to tackle waste and expansion of cities into ex-dump sites are strong drivers for large-scale deployment of WTE systems in the Kingdom.
Saudi Arabia has tremendous waste-to-energy potential due to plentiful availability of good quality municipal waste. Modern waste-to-energy technologies, such as RDF-based incineration, gasification, pyrolysis and anaerobic digestion have the ability to transform power demand and waste management scenario in the country.
A typical 250 – 300 tons per day garbage-to-energy plant can produce around 3 – 4 MW of electricity and a network of such plants in cities around the country can make a real difference in waste management as well as energy sectors. In fact, such plants also produce tremendous about of heat energy which can be utilized in process industries and district cooling systems, further maximizing their usefulness.
Around the world, waste-to-energy finds wide acceptance as a tool to manage urban wastes, with more than 1,000 waste-to-energy plants in operation globally, especially in Europe, China and the Asia-Pacific. However, waste-to-energy is struggling to get off-the-ground in Saudi Arabia due to several issues, the main reason being the cheap and plentiful availability of oil which prevents decision-makers to set effective regulations for waste-to-energy development in the country.
Waste-to-Energy is widely accepted as a part of sustainable waste management strategy worldwide.
Policy-makers in KSA should consider waste-to-energy as a sustainable waste management solution, rather than as a power-producing industry. Unlike Western countries, waste management services are practically free-of-cost for the waste generators which act as a deterrent for governmental investment in new waste management solutions and technologies, such as waste-to-energy. Infact, waste collection, transport and disposal methods in Saudi Arabia do not match the standards of a developed country.
Vision 2030, touted as most comprehensive economic reform package in Saudi history, puts forward a strong regulatory and investment framework to develop Saudi waste-to-energy sector. An ambitious target of 3GW of energy from waste is to be achieved by 2025. A methodical introduction of modern waste management techniques like material recovery facilities, waste-to-energy systems and recycling infrastructure can significantly improve waste management scenario and can also generate good business opportunities.
To sum up, environmental issues associated with non-sanitary landfills, ineffectiveness of prevalent waste management model and rising energy demand are key drivers for development of waste-to-energy sector in Saudi Arabia.
Middle East is one of the most prolific waste generating regions worldwide with per capita waste production in several countries averaging more than 2 kg per day . High standards of living, ineffective legislation, infrastructural roadblocks, indifferent public attitude and lack of environmental awareness are the major factors responsible for growing waste management problem in the Middle East. Lavish lifestyles are contributing to more generation of waste which when coupled with lack of waste collection and disposal facilities have transformed ‘trash’ into a liability.
The general perception towards waste is that of indifference and apathy. Waste is treated as ‘waste’ rather than as a ‘resource’. There is an urgent need to increase public awareness about environmental issues, waste management practices and sustainable living. Public participation in community-level waste management initiatives is lackluster mainly due to low level of environmental awareness and public education. Unfortunately none of the countries in the region have an effective source-segregation mechanism.
Waste management in Middle East is bogged down by deficiencies in waste management legislation and poor planning. Many countries lack legislative framework and regulations to deal with wastes. Insufficient funds, absence of strategic waste management plans, lack of coordination among stakeholders, shortage of skilled manpower and deficiencies in technical and operational decision-making are some of the hurdles experienced in implementing an integrated waste management strategy in the region. In many countries waste management is the sole prerogative of state-owned companies and municipalities which discourage participation of private companies and entrepreneurs.
Many Middle East nations lack legislative framework and regulations to deal with urban wastes.
Due to lack of garbage collection and disposal facilities, dumping of waste in open spaces, deserts and water bodies is a common sight across the region. Another critical issue is lack of awareness and public apathy towards waste reduction, source segregation and waste management.
A sustainable waste management system demands high degree of public participation, effective laws, sufficient funds and modern waste management practices/technologies. The region can hope to improve waste management scenario by implementing source-segregation, encouraging private sector participation, deploying recycling and waste-to-energy systems, and devising a strong legislative and institutional framework.
The Way Forward
In recent year, several countries, like Qatar, UAE and Oman, have established ambitious solid waste management projects but their efficacy is yet to be ascertained. On the whole, Middle East countries are slowly, but steadily, gearing up to meet the challenge posed by waste management by investing heavily in such projects, sourcing new technologies and raising public awareness.
However the pace of progress is not matched by the increasing amount of waste generated across the region. Sustainable waste management is a big challenge for policy-makers, urban planners and other stake-holders, and immediate steps are needed to tackle mountains of wastes accumulating in cities throughout the Middle East.
Solid waste management situation in Pakistan is a matter of grave concern as more than 5 million people to die each year due to waste-related diseases. In Pakistan roughly 20 million tons of solid waste is generated annually, with annual growth rate of about 2.4 percent. Karachi, largest city in the country, generates more than 9,000 tons of municipal waste daily. All major cities, be it Islamabad, Lahore or Peshawar, are facing enormous challenges in tackling the problem of urban waste. The root factors for the worsening garbage problem in Pakistan are lack of urban planning, outdated infrastructure, lack of public awareness and endemic corruption.
Being the 6th most populated country in the world; there is a lot of consumerism and with it a great deal of waste being produced. Like other developing countries, waste management sector in Pakistan is plagued by a wide variety of social, cultural, legislative and economic issues. In the country, more waste is being produced than the number of facilities available to manage it. Some of the major problems are:
There is no proper waste collection system
Waste is dumped on the streets
Different types of waste are not collected separately
There are no controlled sanitary landfill sites. Opening burning is common.
Citizens are not aware of the relationship between reckless waste disposal and resulting environmental and public health problems
As a result of these problems, waste is accumulating and building up on roadsides, canals, and other common areas and burning trash is common, causing hazardous toxins to be exposed thereby threatening human and environmental health. Among the already few landfill sites that are present, even fewer are in operation. Even within Pakistan’s capital, Islamabad, there are no permanent landfills to be found.
The waste on the roads allows for an ideal environment for various flies to thrive which effects both human health and the health of the environment for other species. The poor solid waste management in Pakistan has caused numerous diseases and environmental problems to rise.
Waste Management Situation in Lahore
In Lahore, the capital of Punjab and the second largest city in Pakistan, there are currently no controlled waste disposal facilities are formal recycling systems, though roughly 27% of waste (by weight) is recycled through the informal sector, Lahore does not have very high performing governmental management in the waste management situation. Instead, the City District Government Lahore established the Lahore Waste Management Company and left the responsibility of the Solid Waste Management in Lahore to them. Beginning in 2011, Lahore Waste Management Company strives to develop a system of SWM that ensures productive collection, recovery, transportation, treatment and disposal of the waste in Lahore.
Lahore Waste Management Company (LWMC) has over 10,000 field workers involved in waste collection and disposal. Though the LWMC is working in phases, 100% collection rates are not seen yet. Lahore currently only has three disposal sites which are no more than dumps, where illegal dumping and trash burning is common. However, there is some resource recovery taking place. It is estimated that 27% of dry recyclables are informally recycled within the city. Additionally a composting plant converts 8% of waste into compost.
In general, the governance over the Waste Management in Lahore is hardly present. Though there are current projects and plans taking place, by the Lahore Waste Management Company for example, in order to achieve a productive and sustainable system in the city it is necessary for all service providers (formal, private, and informal) to take part in decisions and actions.
Current Activities and Projects
According to the United Nations Environment Program, there are six current activities and plans taking place towards an efficient waste management system. These current activities are as follows:
Solid Waste Management Guidelines (draft) prepared with the support of Japan International Cooperation Agency (JICA), Japan.
Converting waste agricultural biomass into energy/ material source – project by UNEP, IETC Japan.
North Sindh Urban Services Corporation Limited (NSUSC) – Assisting the district government in design and treatment of water supply, sanitation and solid waste management
The URBAN UNIT, Urban Sector Policy & Management Unit P & D Department, Punjab. Conducting different seminars on awareness of waste water, sanitation & solid waste management etc.
Lahore Compost (Pvt.) Ltd. only dealing with the organic waste with the cooperation of city district government Lahore, Pakistan. The company is registered as a CDM project with UNFCCC.
Different NGOs are involved at small scale for solid waste collection, and recycling.
Additionally, in November 2013 a German company, agreed to invest in the installation of a 100 megawatt power plant which generates energy from waste from Lahore. Progress is being made on the country’s first scientific waste disposal site in Lakhodair. With this in mind, the Lahore Waste Management Company considered other possible technologies for their Waste-to-Energy project. They opened up applications for international companies to hire as the official consultant for LWMC and their project. The results of the feasibility study results showed that the power plant has the potential to process 1035 tons of municipal waste daily, and generate 5.50 megawatt electricity daily.
The Way Forward
Although SWM policies do exist, the levels at which they are implemented and enforced lack as a result of the governmental institutions lacking resources and equipment. These institutions are primarily led by public sector workers and politicians who are not necessarily the most informed on waste management. For improvements in municipal solid waste management, it is necessary for experts to become involved and assist in the environmental governance.
Due to the multiple factors contributing to the solid waste accumulation, the problem has become so large it is beyond the capacity of municipalities. The former director of the Pakistan Council of Scientific and Industrial Research, Dr. Mirza Arshad Ali Beg, stated, “The highly mismanaged municipal solid waste disposal system in Pakistan cannot be attributed to the absence of an appropriate technology for disposal but to the fact that the system has a lot of responsibility but no authority.” Laws and enforcement need to be revised and implemented. The responsibility for future change is in the hands of both the government, and the citizens.
Waste practices in the Pakistan need to be improved. This can start with awareness to the public of the health and environment impacts that dumped and exposed waste causes. It is imperative for the greater public to become environmentally educated, have a change in attitude and take action.
Waste management is an important tool for curbing climate change and for keeping our environment clean and healthy. Methane generated from biodegradable wastes is a powerful greenhouse gas, and when it’s not captured and used as a fuel it contributes to rapid warming of the atmosphere. Estimates suggest that biodegradable waste in dump sites and uncapped landfill sites are contributing far more methane to the atmosphere than previously thought. What’s more, urban food waste is predicted to increase by 44% from 2005 to 2025, and with no proper management in place, will significantly add to global greenhouse gas emissions.
Worryingly, 38 of the world’s 50 largest dumps are close to the sea, contributing to marine and coastal pollution. The accumulation of plastics in the marine food chain is causing global concern. While we don’t yet know how to clean the oceans, stemming the flow of waste into marine environments would be a step in the right direction.
40% of the world’s waste ends up in open dumps. These aren’t even what you’d call “landfill”. They don’t have any impervious lining to prevent noxious leachate from entering the surrounding environment, nor are they capped to prevent the spread of disease. In fact, in India, the Philippines and Indonesia, the health risk from open dumping of waste is greater than the risk of malaria[i].
3.5 billion people in the world lack access to proper waste management. That figure is expected to grow to 5 billion by 2050. Respiratory diseases, gastrointestinal diseases and occupational health risks add to the misery experienced by the 50,000+ people living from open dumps.
Waste is any material that is no longer wanted for its original purpose. The owner doesn’t have a need for it, and so discards it. Even valuable items can and do end up as waste purely because someone has thrown them away. The recent (and rather brilliant) BBC programme Hugh’s War on Waste shone the spotlight on attitudes towards disposable fashion. A look through the bins of a typical street uncovered a startling amount of clothing that had been thrown away, despite it still being in perfectly good condition. This highlights a simple fact: there is plenty of value in waste.
Estimates suggest there are 40 million people globally who are making their living from waste – half of these are working informally.
During the last recession in the UK, the waste management sector was one of the only industries to keep growing, resulting in it being termed the “Green Star of the Economy”.
Showing people how to turn a waste stream into something valuable isn’t rocket science. There are lots of examples of informal, community-based, grassroots recycling and upcycling projects that generate wealth for the poorest in society.
Internet is allowing simple waste processing techniques to be replicated all over the world, and helping make that information accessible is one of the most fulfilling aspects of my career.
“Give a man a fish and he can eat for a day. Show a man how to fish and he can eat for the rest of his life.” Teaching people how to make valuable products from waste is important. But just as important, is passing on the business skills to be able to identify a market, factor in costs, check out the competition, market their products and run a successful business.
Development work in the waste arena needs to address both sides of the coin, and in doing so will enable people to start up their own businesses, in their own communities, and generate wealth organically. That’s far more valuable than delivering aid in a ready-made package (which incidentally rarely works – there’s a great TED Talk on this topic by Ernesto Sirolli, called “Want to help someone? Shut up and listen”).
Why closing dumps isn’t a silver bullet
The proliferation of megacities, particularly in developing countries, is causing a health crisis. Decent waste management is an indicator of good governance – that is, if a council or government can collect taxes and provide a waste management service, then it most likely isn’t (very) corrupt. However, in many places where corruption or other forms of bad or weak governance prevail, top-down solutions are notoriously difficult to implement.
Often, when the world’s attention turns to an open dump, the government responds by closing it and the journalists go home. This is what happened with Smokey Mountain dumpsite in the Philippines (and many others around the world). All that happens is another open dump emerges nearby, and the scavengers move to the new site.
The problem is that if there is no alternative solution in place, people will discard of their waste in the only ways available – dumping it or burning it; and the poor will follow the waste.
Replacing an open dump with a government-controlled waste management system isn’t a silver bullet either. The losers, again, are the hundreds, and sometimes thousands of men, women and children who live from scavenging from the dump. It may seem horrific to many of us, but the truth is that if you take that opportunity to earn a paltry living away from the poorest in society, they will starve. Solutions need to be inclusive.
Power to the people
To close dump sites, you need to have a workable alternative solution in place. You need to have regular waste collection taking place, and you need somewhere to take it. Building materials recovery facilities alongside existing open dumps is one idea. Informal waste pickers who are currently working in dangerous conditions on the dumpsite can gain employment (or better still, form a cooperative) sorting recyclable materials and reducing the amount of real “waste” that needs to be disposed of.
For example, Wecyclers in Lagos, Nigeria employs people to cycle around collecting recyclable materials from households. In return for their source-separated waste, the householder receives a small reward.
In Bangalore, IGotGarbage has harnessed the power of phone apps to enable people who were previously waste pickers to be called directly to a house to collect the waste materials. Solutions like this work because they continue to provide livelihoods for people, while taking waste off the streets.
The need for appropriate technology
There will always be something left though: the stuff that really has little value other than the energy embodied in it. In industrialised countries, energy-from-waste incinerators have become popular. Seen as a clean alternative to landfill, these facilities burn the waste, release the energy, and convert it into heat, electricity and ash. Some of that ash (from the air pollution control system) still needs to be disposed of in specially-prepared hazardous waste landfill sites. The remainder, being fairly benign, can be used to make concrete building blocks.
However, incinerators are fairly technology-heavy, rendering them unsuitable for many developing country contexts.
A problem that we’ve witnessed is that waste management companies from industrialised nations try to wholesale their technology in developing countries. The technology is usually unaffordable, and even if the capital can be raised to procure a facility, as soon as something breaks down the whole solution can fall apart.
There is a need for information about simple waste processing technologies to become more open-sourced. Smart future-thinking businesses could capitalise on selling blueprints rather than entire prefabricated facilities. Most of the time it’s far cheaper to fabricate something locally, and also means that when something breaks it can be fixed.
The continuing need for landfill
The fact is that in most cases, a standard, lined landfill site with landfill gas capture is still the most appropriate answer for non-recyclable waste. Add to that a well-organised, low-cost waste collection service with source separation of recyclable materials and biodegradable waste, and you have a relatively affordable solution that is better for the climate, better for health, better for the local economy, and contributes to a more sustainable future.
Landfill may seem very unfashionable to those of us who work in the recycling sector, but nevertheless it will remain a necessity both in developed and developing countries for the foreseeable future.
Joining forces and stepping stones
The success of the Sustainable Development Goals and potential Climate Change Agreement depend on developed and developing countries working together. Miguel Arias Cañete, the EU climate commissioner, said the Climate Coalition alliance showed that developed and developing countries could work together with a common interest. “These negotiations are not about them and us. They are about all of us, developed and developing countries, finding common ground and solutions together. We urge other countries to join us. Together we can do it.”
Necessity is the mother of invention, and we are facing a waste crisis of unprecedented proportion. The potential for waste management in reducing GHG emissions has never been more pertinent. Waste and development practitioners, academics and entrepreneurs around the world are working together more and more to help bring about the change we want to see, which will benefit the billions of people suffering from poor waste management, and the rest of us who share a warming planet – and share the burden of climate change and poverty.
By sharing knowledge through platforms such as beWasteWise and ISWA, and through initiatives like WasteAid, WASTE and Wiego, we can start making a dent in this very large problem.
No silver bullets, but lots of small stepping stones in the right direction.
Note: The original and unabridged version of the article can be found at this link. Please visit http://zlcomms.co.uk/ for more information about the author.
China is the world’s largest waste generator, producing as much as 175 million tons of waste every year. With a current population surpassing 1.37 billion and exponential trends in waste output expected to continue, it is estimated that China’s cities will need to develop an additional hundreds of landfills and waste-to-energy plants to tackle the growing waste management crisis.
China’s three primary methods for municipal waste management are landfills, incineration, and composting. Nevertheless, the poor standards and conditions they operate in have made waste management facilities generally inefficient and unsustainable. For example, discharge of leachate into the soil and water bodies is a common feature of landfills in China. Although incineration is considered to be better than landfills and have grown in popularity over the years, high levels of toxic emissions have made MSW incineration plants a cause of concern for public health and environment protection.
Salman Zafar, a renowned waste management, waste-to-energy and bioenergy expert was interviewed to discuss waste opportunities in China. As Mr. Zafar commented on the current problems with these three primary methods of waste management used by most developing countries, he said, “Landfills in developing countries, like China and India, are synonymous with huge waste dumps which are characterized by rotting waste, spontaneous fires, toxic emissions and presence of rag-pickers, birds, animals and insects etc.” Similarly, he commented that as cities are expanding rapidly worldwide, it is becoming increasingly difficult to find land for siting new landfills.
On incineration, Zafar asserted that this type of waste management method has also become a controversial issue due to emission concerns and high technology costs, especially in developing countries. Many developers try to cut down costs by going for less efficient air pollution control systems”. Mr. Zafar’s words are evident in the concerns reflected in much of the data that waste management practices in China are often poorly monitored and fraudulent, for which data on emission controls and environmental protection is often elusive.
Similarly, given that management of MSW involves the collection, transportation, treatment and disposal of waste, Zafar explains why composting has also such a small number relative to landfills for countries like China. He says, “Composting is a difficult proposition for developing countries due to absence of source-segregation. Organic fraction of MSW is usually mixed with all sorts of waste including plastics, metals, healthcare wastes and industrial waste which results in poor quality of compost and a real risk of introduction of heavy metals into agricultural soils.”
Given that China’s recycling sector has not yet developed to match market opportunities, even current treatment of MSW calls for the need of professionalization and institutionalization of the secondary materials industry.
While MSW availability is not an issue associated with the potential of the resource given its dispersion throughout the country and its exponential increase throughout, around 50 percent of the studies analyzed stated concerns for the high moisture content and low caloric value of waste in China, making it unattractive for WTE processes.
Talking about how this issue can be dealt with, Mr. Zafar commented that a plausible option to increase the calorific value of MSW is to mix it with agricultural residues or wood wastes. Thus, the biomass resources identified in most of the studies as having the greatest potential are not only valuable individually but can also be processed together for further benefits.
Among the major challenges on the other hand, were insufficient or elusive data, poor infrastructure, informal waste collection systems and the lack of laws and regulations in China for the industry. Other challenges included market risk, the lack of economic incentives and the high costs associated with biomass technologies. Nevertheless, given that the most recurring challenges cited across the data were related to infrastructure and laws and regulations, it is evident that China’s biomass policy is in extreme need of reform.
China’s unsustainable management of waste and its underutilized potential of MSW feedstock for energy and fuel production need urgent policy reform for the industry to develop. Like Mr. Zafar says, “Sustainable waste management demands an integration of waste reduction, waste reuse, waste recycling, and energy recovery from waste and landfilling. It is essential that China implements an integrated solid waste management strategy to tackle the growing waste crisis”.
China’s government will play a key role in this integrated solid waste management strategy. Besides increased cooperation efforts between the national government and local governments to encourage investments in solid waste management from the private sector and foster domestic recycling practices, first, there is a clear need to establish specialized regulatory agencies (beyond the responsibilities of the State Environmental Protection Administration and the Ministry of Commerce) that can provide clearer operating standards for current WTE facilities (like sanitary landfills and incinerators) as well as improve the supervision of them.
It is essential that China implements an integrated solid waste management strategy to tackle the growing waste crisis
Without clear legal responsibility assigned to specialized agencies, pollutant emissions and regulations related to waste volumes and operating conditions may continue to be disregarded. Similarly, better regulation in MSW management for efficient waste collection and separation is needed to incentivize recycling at the individual level by local residents in every city. Recycling after all is complementary to waste-to-energy, and like Salman Zafar explains, countries with the highest recycling rates also have the best MSW to energy systems (like Germany and Sweden).
Nevertheless, without a market for reused materials, recycling will take longer to become a common practice in China. As Chinese authorities will not be able to stop the waste stream from growing but can reduce the rate of growth, the government’s role in promoting waste management for energy production and recovery is of extreme importance.
The high rate of population growth, urbanization and economic expansion in the Middle East is not only accelerating consumption rates but also increasing the generation rate of all sorts of waste. The gross urban waste generation quantity from Middle East countries is estimated at more than 150 million tons annually. Bahrain, Saudi Arabia, UAE, Qatar and Kuwait rank in the top-ten worldwide in terms of per capita solid waste generation.
Saudi Arabia produces around 15 million tons of garbage each year. With an approximate population of about 28 million, the kingdom produces approximately 1.3 kilograms of waste per person every day. According to a recent study conducted by Abu Dhabi Center for Waste Management, the amount of waste in UAE totaled 4.892 million tons, with a daily average of 6935 tons in the city of Abu Dhabi, 4118 tons in Al Ain and 2349 tons in the western region. Countries like Kuwait, Bahrain and Qatar have astonishingly high per capita waste generation rate, primarily because of high standard of living and lack of awareness about sustainable waste management practices.
In Middle East countries, huge quantity of sewage sludge is produced on daily basis which presents a serious problem due to its high treatment costs and risk to environment and human health. On an average, the rate of wastewater generation is 80-200 litres per person each day and sewage output is rising by 25 percent every year. According to estimates from the Drainage and Irrigation Department of Dubai Municipality, sewage generation in the Dubai increased from 50,000 m3 per day in 1981 to 400,000 m3 per day in 2006.
Municipal solid waste in the Middle East is mainly comprised of organics, paper, glass, plastics, metals, wood etc. Municipal solid waste can be converted into energy by conventional technologies (such as incineration, mass-burn and landfill gas capture) or by modern conversion systems (such as anaerobic digestion, gasification and pyrolysis).
At the landfill sites, the gas produced by the natural decomposition of MSW is collected from the stored material and scrubbed and cleaned before feeding into internal combustion engines or gas turbines to generate heat and power. In addition, the organic fraction of MSW can be anaerobically stabilized in a high-rate digester to obtain biogas for electricity or steam generation.
Anaerobic digestion is the most preferred option to extract energy from sewage, which leads to production of biogas and organic fertilizer. The sewage sludge that remains can be incinerated or gasified/pyrolyzed to produce more energy. In addition, sewage-to-energy processes also facilitate water recycling.
Thus, municipal solid waste can also be efficiently converted into energy and fuels by advanced thermal technologies. Infact, energy recovery from MSW is rapidly gaining worldwide recognition as the 4th R in sustainable waste management system – Reuse, Reduce, Recycle and Recover.
Food residuals are an untapped renewable energy source that mostly ends up rotting in landfills, thereby releasing greenhouse gases into the atmosphere. Food residuals are difficult to treat or recycle since it contains high levels of sodium salt and moisture, and is mixed with other waste during collection. Major generators of food wastes include hotels, restaurants, supermarkets, residential blocks, cafeterias, airline caterers, food processing industries, etc.
According to EPA, about 63.1 million tons of food waste was thrown away into landfills or incinerators the United States in 2018. As far as United Kingdom is concerned, households threw away 6.6 million tons of food each year. These statistics are an indication of tremendous amount of food waste generated all over the world.
The proportion of food residuals in municipal waste stream is gradually increasing and hence a proper food waste management strategy needs to be devised to ensure its eco-friendly and sustainable disposal. Currently, only about 3 percent of food waste is recycled throughout U.S., mainly through composting. Composting provides an alternative to landfill disposal of food waste, however it requires large areas of land, produces volatile organic compounds and consumes energy. Consequently, there is an urgent need to explore better recycling alternatives.
Anaerobic digestion has been successfully used in several European and Asian countries to stabilize food wastes, and to provide beneficial end-products. Sweden, Austria, Denmark, Germany and England have led the way in developing new advanced biogas technologies and setting up new projects for conversion of food waste into energy.
Anaerobic Digestion of Food Waste
Anaerobic digestion is the most important method for the treatment of organic waste, such as food residuals, because of its techno-economic viability and environmental sustainability. Anaerobic digestion generates renewable energy from food waste in the form of biogas and preserves the nutrients which are recycled back to the agricultural land in the form of slurry or solid fertilizer.
The relevance of biogas technology lies in the fact that it makes the best possible use of various organic wastes as a renewable source of clean energy. A biogas plant is a decentralized energy system, which can lead to self-sufficiency in heat and power needs, and at the same time reduces environmental pollution. Thus, anaerobic digestion of food waste can lead to climate change mitigation, economic benefits and landfill diversion opportunities.
Of the different types of organic wastes available, food waste holds the highest potential in terms of economic exploitation as it contains high amount of carbon and can be efficiently converted into biogas and organic fertilizer. Food waste can either be used as a single substrate in a biogas plant, or can be co-digested with organic wastes like cow manure, poultry litter, sewage, crop residues, slaughterhouse wastes, etc.
Renewable Energy from Food Residuals
The feedstock for the food waste-to-energy plant includes leftover food, vegetable refuse, stale cooked and uncooked food, meat, teabags, napkins, extracted tea powder, milk products, etc. Raw waste is shredded to reduce to its particle size to less than 12 mm. The primary aim of shredding is to produce a uniform feed and reduce plant “down-time” due to pipe blockages by large food particles. It also improves mechanical action and digestibility and enables easy removal of any plastic bags or cling-film from waste.
Fresh waste and re-circulated digestate (or digested food waste) are mixed in a mixing tank. The digestate is added to adjust the solids content of the incoming waste stream from 20 to 25 percent (in the incoming waste) to the desired solids content of the waste stream entering the digestion system (10 to 12 percent total solids). The homogenized waste stream is pumped into the feeding tank, from which the anaerobic digestion system is continuously fed. Feeding tank also acts as a pre-digester and subjected to heat at 55º to 60º C to eliminate pathogens and to facilitate the growth of thermophilic microbes for faster degradation of waste.
From the predigestor tank, the slurry enters the main digester where it undergoes anaerobic degradation by a consortium of Archaebacteria belonging to Methanococcus group. The anaerobic digester is a CSTR reactor having average retention time of 15 to 20 days. The digester is operated in the mesophilic temperature range (33º to 38°C), with heating carried out within the digester. Food waste is highly biodegradable and has much higher volatile solids destruction rate (86 to 90 percent) than biosolids or livestock manure. As per conservative estimates, each ton of food waste produces 150 to 200 m3 of biogas, depending on reactor design, process conditions, waste composition, etc.
Biogas contains significant amount of hydrogen sulfide (H2S) gas that needs to be stripped off due to its corrosive nature. The removal of H2S takes place in a biological desulphurization unit in which a limited quantity of air is added to biogas in the presence of specialized aerobic bacteria that oxidizes H2S into elemental sulfur. The biogas produced as a result of anaerobic digestion of waste is sent to a gas holder for temporary storage. Biogas is eventually used in a combined heat and power (CHP) unit for its conversion into thermal and electrical energy in a cogeneration power station of suitable capacity. The exhaust gases from the CHP unit are used for meeting process heat requirements.
The digested substrate leaving the reactor is rich in nutrients like nitrogen, potassium and phosphorus which are beneficial for plants as well as soil. The digested slurry is dewatered in a series of screw presses to remove the moisture from slurry. Solar drying and additives are used to enhance the market value and handling characteristics of the fertilizer.
Diverting Food from Landfills
Food residuals are one of the single largest constituents of municipal solid waste stream. Diversion of food waste from landfills can provide significant contribution towards climate change mitigation, apart from generating revenues and creating employment opportunities. Rising energy prices and increasing environmental pollution makes it more important to harness renewable energy from food scraps and create a sustainable food supply chain.
Anaerobic digestion technology is widely available worldwide and successful projects are already in place in several European as well as Asian countries that makes it imperative on waste generators and environmental agencies to root for a sustainable food waste management system.
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