Solid Waste Management in South Asia: Key Lessons

swm-south-asiaSolid waste management is already a significant concern for municipal governments across South Asia. It constitutes one of their largest costs and the problem is growing year on year as urban populations swell. As with all waste management experiences, we have learned lessons and can see scope for improvement.

Collection and Transportation

There are two factors which have a significant impact on the costs and viability of a waste management system as it relates to collection and transportation: first, the distance travelled between collection and disposal point; and second, the extent to which ‘wet’ kitchen waste can be kept separate from dry waste much of which can be recycled. Separating waste in this way reduces the costs of manual sorting later on, and increases the prices for recyclable materials.

In many larger towns distances become too great for door-to-door collectors to dispose waste directly at the dump site. Arrangements are made to dispose of waste at secondary storage points (large skips) provided by the municipality. However, where these are not regularly emptied, the waste is likely to be spread beyond the bins, creating a further environmental hazard.

Ideally, and if suitable land can be found, a number of smaller waste disposal sites located around a town would eliminate this problem. With significant public awareness efforts on our part, and continual daily reminders to home-owners, we were able to raise the rate of household separation to about 60%, but once these reminders became less frequent, the rate dropped rapidly back to around 25%. The problem is compounded in larger cities by the unavailability of separated secondary storage bins, so everything is mixed up again at this point anyway, despite the best efforts of householders.

If rates are to be sustained, it requires continual and on-going promotion in the long term. The cost of this has to be weighed against the financial benefit of cleaner separated waste and reduced sorting costs. Our experience in Sri Lanka shows how important a role the Local Authority can play in continuing to promote good solid waste management practices at the household level.

Home Composting

Our experience with home composting shows that complete coverage, with every household using the system, is very unlikely to be achieved. Where we have promoted it heavily and in co-operation with the Local Authority we have found the sustained use of about 65% of the bins. Even this level of coverage, however, can have an important impact on waste volumes needing to be collected and disposed of. At the same time it can provide important, organic inputs to home gardening, providing a more varied and nutritious diet for poor householders.

Waste to Compost and Energy

The variety of technologies we have demonstrated have different advantages and disadvantages. For some, maintenance is more complicated and there can be issues of clogging. For the dry-fermentation chambers, there is a need for a regular supply of fresh waste that has not already decomposed. For other systems requiring water, quite large amounts may be needed. All of these technical challenges can be overcome with good operation and maintenance practices, but need to be factored in when choosing the appropriate technology for a given location.

The major challenge for compost production has been to secure regular sales. The market for compost is seasonal, and this creates an irregular cash flow that needs to be factored in to the business model. In Bangladesh, a significant barrier has been the need for the product to be officially licensed. The requirements for product quality are exacting in order to ensure farmers are buying a product they can trust. However, the need for on-site testing facilities may be too prescriptive, creating a barrier for smaller-scale operations of this sort. Possibly a second tier of license could be created for compost from waste which would allow sales more easily but with lower levels of guarantees for farmers.

Safe Food Production and Consumption

Community people highly welcomed the concept of safe food using organic waste generated compost. In Sri Lanka, women been practicing vertical gardening which meeting the daily consumption needs became source of extra income for the family. Female organic fertilizer entrepreneurs in Bangladesh are growing seasonal vegetables and fruits with compost and harvesting more quality products. They sell these products with higher price in local and regional markets as this is still a niche market in the country. The safe food producers require financial and regulatory support from the government and relevant agencies on certification and quality control to raise and sustain market demand.

The concept of safe food using organic waste generated compost is picking up in South Asia

The concept of safe food using organic waste generated compost is picking up in South Asia

Conclusion

Solid waste management is an area that has not received the attention it deserves from policy-makers in South Asia nations. There are signs this may change, with its inclusion in the SDGs and in many INDCs which are the basis of the Paris Climate Agreement. If we are to meet the challenge, we will need new approaches to partnerships, and the adoption of different kinds of systems and technologies. This will require greater awareness and capacity building at the Local Authority level. If national climate or SDG targets are to be met, they will need to be localised through municipalities. Greater knowledge sharing at national and regional levels through municipal associations, regional bodies such as SAARC and regional local authority associations such as Citynet, will be an important part of this.

Practical Action’s key messages for regional and national policy makers, based on our experience in the region in the last 5 years, are about the need for:

  • creating new partnerships for waste collection with NGOs and the informal sector,
  • considering more decentralised approaches to processing and treatment, and
  • recognising the exciting potential for viable technologies for generating more value from waste

Model for Change: Practical Action’s Experience in SWM

Waste-Management-BangladeshWaste management systems can be divided into a number of steps from collection, storage, transportation, processing, treatment, recycling and final disposal. Integrated solid waste management refers to this entire process and aims to maximise resource use efficiency, with minimal amounts ending up in final disposal sites. During Practical Action’s recent work in the South Asia region, we have gained particular experiences in terms of firstly waste collection, storage and transportation; and secondly waste processing in particular of organic waste.

Collection and Transportation

In many cities, waste collection services fail to reach all areas of the town or city. People are left to manage their own waste, which they do by burning and burying it, or dumping on open spaces. Sometimes large bins or skips are provided but they may be irregularly emptied, and also overflow when the contents is picked over by waste pickers and animals. In Bangladesh, in order to help increase the overall capacity for collecting household waste, Practical Action has promoted a door-to-door collection service run by local NGOs. Residents pay a service charge in addition to their municipal rates, but in return they receive a regular service, leading to a cleaner neighbourhood.

In Faridpur, the local NGO, WORD, with technical backstopping from Practical Action serves more than 5,000 customers with waste collection. There are three main types of customer, non-slum households, slum households and institutions. Slum-based households are charged the lowest tariffs (minimum BDT 10) while the institutional rate is highest (minimum BDT 150). The numbers of slum households is small because the alternative option of localized composting (with a barrel system) was widely taken up. This is easier than collection through vans and is useful for slum people as they can use the compost later. Waste collectors use small rickshaw vans for the collection service. Recently we have also introduced small small rickshaw vans and small motorized versions for the collection service.

The waste is taken to a composting facility where it is sorted and the organic portion is separated for composting, and in some cases for generating biogas. In 2008, WORD started the waste collection business with only 525 customers. In the last 8 years, the number has increased more than tenfold (5,100 customer per month) making the solid waste management a viable business. It has not only contributed to a better living environment, but also generated green and dignified jobs for 21 waste workers.

The municipal conservancy department continues to play a regulatory and coordinating role through the Waste Management Steering Committee. This meets regularly to discuss any emerging issues and review the progress of door-to-door collection services. The conservancy department continues to manage the sweeping of streets and drains, and collection of waste from some areas of the town, from vegetable markets and slaughter houses. The only recycling and reuse of organic waste is done by WORD, as all municipal waste for now continues to be disposed at an open dumping site where no further treatment, sorting or reuse takes place.

In Nepal, Practical Action has facilitated organic waste management under a public-private partnership model. For example, in Butwal Municipality, a private firm, Marry Gold Concern, collects and manages wastes from 400 households with a monthly service fee of NPR 50 (GBP 0.33) in an area called Ramnagar. The company employs three operators for collecting and managing waste from low income communities. A compost plant has been set up which processes up to 10 metric tonnes of organic waste and generate 5 metric tonnes of compost per month. In addition, recyclable waste, mainly plastic, is sold to scrap dealers, creating another source of income.

Recycling and Disposal by Forming Associations and Enterprises

In Bangladesh, collection services have been organised through existing local NGOs. In Nepal, Practical Action has instead helped to form different groups of Informal Waste Workers (IWW) such as street waste pickers, waste segregators, pheriya (dry waste pickers), scrap owners and door to door collectors. We have worked intensively  with IWW from five municipalities of Kathmandu Valley. We have facilitated the establishment of a IWWs association called Samyukta Safai Jagaran (SASAJA), and the first waste workers’ cooperative with the same name. These organisations have distributed identity cards to members to increase their recognition as an ‘official’ part of the waste management system. We provided basic safety equipment to 5,622 IWWs, including rain boots/shoes, gloves, masks, raincoats, windcheaters with trouser and wrapper, aprons, cap etc. to minimize health risks.

Basic safety equipment is essential to minimize health risks to informal recycling sector.

Basic safety equipment is essential to minimize health risks to informal recycling sector.

Following capacity building and skill enhancement training from Practical Action, many of the IWW group members have established waste-based enterprises. For example, plastic tearing (PET bottle and carton crushing or pressing) for recycling and reuse; paper recycling and mechanical composting of organic waste. This approach has been scaled up in other municipalities in Chitwan and Rupadehi districts reaching around 350 IWWs there.

Reducing Waste through Home Composting

In Nepal and Sri Lanka, and in some slum communities in Bangladesh, we have promoted barrel composting of organic waste. This has the dual benefit of producing compost locally which can be used for home gardening, and reducing the amount of waste that needs to be collected and disposed of elsewhere. It can reduce the amount of organic waste coming in to the waste collection stream by about 20-30%. It requires community involvement in waste management system as well as frequent monitoring and troubleshooting. This process ensures source segregation of waste, a necessary condition for proper implementation of the 3R system (reuse, reduce and recycle).

Practical Action has distributed more than 2,000 compost bins in Sri Lanka. Especially in Galle, Kurunegala and Akkaraipattu cities where we have distributed about 1,500 home composting bins from 2006 to 2016. More than 65% of the bins are being regularly used.

Our experience shows that once a locality is provided with home composting, the volume of organic waste into the municipal collection system is reduced around 20-30%. However, this varies greatly by locations. If the local authority strictly monitors the compost bin usage and provides troubleshooting support, waste reduction can reach up to 30%.

Both Kurunegala and Galle municipal councils have upscaled the distribution of bins city-wide with the support of national government funding. This technology was taken up by the private sector and other municipal councils. It has been used widely in the country as a solution for reducing organic waste coming in to the waste collection system. For example, Kandy municipal council has adopted the technology with strict restriction on organic waste collection in the municipality collection system.

The Provincial Agriculture department in Kurunegala and the Coconut cultivation board in Akkaraipattu are both promoting organic agriculture with the usage of composting and are using Practical Action’s work as examples for expansion. The central government has provided seeds and fertilizer to city dwellers, including the urban poor, to promote home gardening.

This has been further expanded by Kurunegala municipal council which has distributed potted plants. Some of the vertical gardening structures promoted by Practical Action are now included in urban gardening models of the Western Province Urban Agriculture unit.

Waste-to-Energy in China: Perspectives

garbage-chinaChina is the world’s largest MSW 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.

Prevalent Issues

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, 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.

Top Challenges

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”.

Future Perspectives

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

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.

Waste Management Perspectives for Military

waste-management-militaryWaste management has a profound impact on all sections of the society, and military is no exception. With increasing militarization, more wars and frequent armed conflicts, protection of the environment has assumed greater significance for military in armed conflicts as well as peacetime operations. Tremendous amount of waste is generated by military bases and deployed forces in the form of food waste, papers, plastics, metals, tires, batteries, chemicals, e-waste, packaging etc.

War on Waste

Sustainable management of waste is a good opportunity for armed forces to promote environmental stewardship, foster sustainable development and generate goodwill among the local population and beyond. Infact, top military bases in the Western world, like Fort Hood and Fort Meade, have an effective strategy to counter the huge amount of solid waste, hazardous waste and other wastes generated at these facilities.

Waste management at military bases demands an integrated framework based on the conventional waste management hierarchy of 4Rs – reduction, reuse, recycling and recovery (of energy). Waste reduction (or waste minimization) is the top-most solution to reduce waste generation at military bases which demands close cooperation among different departments, including procurement, technical services, housing, food service, personnel. Typical waste reduction strategies for armed forces includes

  • making training manuals and personnel information available electronically
  • reducing all forms of packaging waste
  • purchasing products, such as food items, in bulk
  • purchasing repairable, long-lasting and reusable items

Due to large fraction of recyclables in the waste stream, recycling is an attractive proposition for the armed forces. However, environmental awareness, waste collection infrastructure, and modern equipment are essential for the success of any waste management strategy in a military installation. Food waste and yard waste (or green waste) can be subjected to anaerobic digestion or composting to increase landfill diversion rates and obtain energy-rich biogas (for cooking/heating) and nutrient-rich fertilizer (for landscaping and gardening). For deployed forces, small-scale waste-to-energy systems, based on thermal technologies, can be an effective solution for disposal of combustible wastes, and for harnessing energy potential of wastes.

Key Aspect

Management options for military installations is dependent on size of the population, location, local regulations, budgetary constraints and many other factors. It is imperative on base commanders to evaluate all possible options and develop a cost-effective and efficient waste management plan. The key factors in the success of waste management plan in military bases are development of new technologies/practices, infrastructure building, participation of all departments, basic environmental education for personnel and development of a quality recycling program.

Military installations are unique due to more than one factor including strict discipline, high degree of motivation, good financial resources and skilled personnel. Usually military installations are one of the largest employers in and around the region where they are based and have a very good influence of the surrounding community, which is bound to have a positive impact on overall waste management strategies in the concerned region.

Waste Management Progress in Nigeria’s Delta State

waste-nigeriaWaste management is a serious problem in Nigeria, and Delta State is no exception. It is a problem that starts at a cultural level: many of the populace believe that once they remove waste from their homes it is no longer their concern. It is a problem that starts at a cultural level: many of the populace believe that once they remove waste from their homes it is no longer their concern, and you often see people disposing of their household waste in the streets at night. Once the waste gets out into the streets, it’s perceived as the duty of the government to handle it.

However, I have never yet heard of any Nigerian politician making waste management a feature of his or her manifesto during the election campaign process. Having said that, a few of Nigeria’s political leaders deserve to be commended for coming to terms with the fact that waste has to be managed properly, even if such issues were far from their minds when they entered political office.

Legislation and Framework

Nigeria does have a waste legislation framework in place. Its focus has been on the most toxic and hazardous waste: partly in response to some major pollution incidents in the 1980s, the government took powers in relation to Hazardous Waste in 1988. In the same year, the Federal Environmental Protection Agency was established – and was subsequently strengthened by the addition of an inspectorate and enforcement department arm in 1991, with divisions for standard regulation, chemical tracking and compliance monitoring. These laws have since given rise to regulations and guidelines pertaining to environmental and waste management issues.

Under our laws, waste management in each state is the duty of the local governments that fall within it, but few are taking an active approach to implementing and enforcing the sensible measures that the regulations require. A small number of states have taken over this task from local government, and Delta State’s decision to do this has led to significant new investment in waste management.

One of the fruits of that investment is the Delta State Integrated Waste Management Facility at Asaba for treating both household and clinical waste generated locally. It was developed when the Delta State government decided to put an end to the non-sustainable dumping of waste in Asaba, the state capital.

Integrated Waste Management Facility at Asaba

It is described as an integrated waste management facility because it includes a composting department, a recycling department and a (non-WTE) incineration department. Trucks carrying waste are weighed in as they come into the facility. From the weigh bridge, they move to the relevant reception bay – there are separate ones for household and clinical wastes – to tip their load, and are then weighed again on the way out.

Clinical waste is taken directly for incineration, but household wastes are sent along conveyors for sorting. Recyclables and compostable materials are, so far as possible, separated both from other waste and from one another. Each recyclable stream ends up in a chamber where it can be prepared for sale. The compostable materials are moved to the composting section, which uses aerated static pile composting.

The remaining waste is conveyed into the three incinerators – moving grate, rotary kiln and fixed end– for combustion. The resulting ash is recycled by mixing it with cement and sharp sand and moulding it into interlocking tiles. The stacks of the three incinerators are fitted with smoke cleaning systems to reduce emissions. The process produces wastewater, which is channelled to a pit where it is treated and reused. Overall, 30% of the waste is composted, 15% recycled and 55% incinerated.

There are many examples of sophisticated waste infrastructure being built in developing countries, but failing because the necessary collection systems were not in place to support them. To ensure that this problem is avoided at Asaba, the Delta State government? is working with a group known as the Private Sector Participants (PSP). Each member of this group has trucks assigned to them and has been directed to collect household waste from different parts of the city, for delivery to the facility for treatment. The arrangements made by each PSP are different: some collect from outside individual properties, and some from communal sites; most collect waste that is found in the streets; and while each is subsidised by the state, households also have to pay towards the cost.

Before the Asaba facility was developed, most of the wastes generated in Asaba were disposed of at a dumpsite just adjacent to the Delta State Airport. This created a pungent odour, as well as visual disamenity for people nearby. A great deal of remediation work is now taking place at the dumpsite, which is vastly improving the local environmental quality.

War on Waste

Of course, although this is an improvement there remains more to do. First on the list is education. People do not know how sustainable waste management can impact positively in their lives, reducing their exposure to toxins as well as improving their surroundings. Nor do they understand that recycling a beverage can or a plastic bottle will cost less than producing one from virgin materials and will have a lesser environmental impact. There remains a good deal of cultural change and education that is needed before people will stop throwing waste and litter on the streets – but there are few countries where, to some extent, the same would not be true.

Next is the lack of infrastructure. Nigeria has 36 states and a federal capital, yet the facility in Asaba is the first publicly commissioned one of its kind in the country; there are also some privately owned incinerators that a few companies in Port Harcourt use to treat wastes from vessels (ships), hospitals and industries. Lagos state and Abuja are relatively advanced, simply by virtue of having put in place a few managed landfills, but they are still far from having the level of facility that Asaba can now boast.

The backbone of Asaba’s progress is the state government’s commitment to put a proper waste management? solution in place. We’ve seen the impact in the form of infrastructure, collections and remediation, and law enforcement work is starting to change people’s perception about waste management in Delta State. At the moment, plans are being concluded to setup another facility in Warri, Delta State’s industrial hub, which will be twice the size of the Asaba facility.?

My hope is that the progress made by Delta State will be a beacon for other states’ governments. The example we are providing of cleaner, hygienic, more environmentally responsible waste management, and the positive changes that is bringing about, should inspire new development elsewhere in the country, which could equal or even exceed Delta State’s results. So whilst Nigeria’s track record on waste may leave a lot to be desired, the path ahead could be a great deal more promising.

Note: The article is being republished with the kind permission of our collaborative partner Isonomia. The original article can be found at this link.

Different Strategies in Composting

Composting can be categorized into different categories depending on the nature of decomposition process. The three major segments of composting are anaerobic composting, aerobic composting, and vermicomposting. In anaerobic composting, the organic matter is decomposed in the absence of air. Organic matter may be collected in pits and covered with a thick layer of soil and left undisturbed six to eight months. Anaerobic microorganisms dominate and develop intermediate compounds including methane, organic acids, hydrogen sulphide and other substances. The process is low-temperature, slow and the compost formed may not be completely converted and may include aggregated masses and phytotoxic compounds.

Aerobic Composting

Aerobic composting is the process by which organic wastes are converted into compost or manure in presence of air. In this process, aerobic microorganisms break down organic matter and produce carbon dioxide, ammonia, water, heat and humus, the relatively stable organic end-product. Although aerobic composting may produce intermediate compounds such as organic acids, aerobic microorganisms decompose them further. The resultant compost, with its relatively unstable form of organic matter, has little risk of phytotoxicity. The heat generated accelerates the breakdown of proteins, fats and complex carbohydrates such as cellulose and hemicellulose. Hence, the processing time is shorter. Moreover, this process destroys many micro-organisms that are human or plant pathogens, as well as weed seeds, provided it undergoes sufficiently high temperature. Although more nutrients are lost from the materials by aerobic composting, it is considered more efficient and useful than anaerobic composting for agricultural production.

There are a variety of methods for aerobic composting, the most common being the Heap Method, where organic matter needs to be divided into three different types and to be placed in a heap one over the other, covered by a thin layer of soil or dry leaves. This heap needs to be mixed every week, and it takes about three weeks for conversion to take place. The process is same in the Pit Method, but carried out in specially constructed pits. Mixing has to be done every 15 days, and there is no fixed time in which the compost may be ready. Berkley Method uses a labor-intensive technique and has precise requirements of the material to be composted. Easily biodegradable materials, such as grass, vegetable matter, etc., are mixed with animal matter in the ratio of 2:1. Compost is usually ready in 15 days.

Vermicomposting

Vermicomposting is a type of composting in which certain species of earthworms are used to enhance the process of organic waste conversion and produce a better end-product. It is a mesophilic process utilizing microorganisms and earthworms. Earthworms feeds the organic waste materials and passes it through their digestive system and gives out in a granular form (cocoons) which is known as vermicompost. Earthworms consume organic wastes and reduce the volume by 40–60 percent. Each earthworm weighs about 0.5 to 0.6 gram, eats waste equivalent to its body weight and produces cast equivalent to about 50 percent of the waste it consumes in a day. The moisture content of castings ranges between 32 and 66 percent and the pH is around 7.

The level of nutrients in compost depends upon the source of the raw material and the species of earthworm. Apart from other nutrients, a fine worm cast is rich in NPK which are in readily available form and are released within a month of application. Vermicompost enhances plant growth, suppresses disease in plants, increases porosity and microbial activity in soil, and improves water retention and aeration.

Food Waste Management in USA

food_wasteFood waste is an untapped energy source that mostly ends up rotting in landfills, thereby releasing greenhouse gases into the atmosphere. Food waste is 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.

In United States, food waste is the third largest waste stream after paper and yard waste. Around 13 percent of the total municipal solid waste generated in the country is contributed by food scraps. According to USEPA, more than 35 million tons of food waste are thrown away into landfills or incinerators each year, which is around 40 percent of all food consumed in the country. As far as United Kingdom is concerned, households throw away around 8 million tons of food each year. These statistics are an indication of tremendous amount of food waste generated all over the world.

Food Waste Management Strategy

The proportion of food waste 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. The two most common methods for food waste recycling are:

  • Composting: A treatment that breaks down biodegradable waste by naturally occurring micro-organisms with oxygen, in an enclosed vessel or tunnel;
  • Anaerobic digestion (AD): A treatment that breaks down biodegradable waste in the absence of oxygen, producing a renewable energy (biogas) that can be used to generate electricity and heat.

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.

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, abattoir wastes, etc.

Food waste is one of the single largest constituent 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 wastes. Anaerobic digestion technology is widely available worldwide and successful projects are already in place in several European as well as Asian countries which makes it imperative on waste generators and environmental agencies in USA to strive for a sustainable food waste management system.

Composting in Qatar

compost-qatarQatar has one of the highest per capita waste generation rates worldwide. In 2012, Qatar generated 8,000 tons of solid waste daily (excluding construction and demolition waste which amounts to 20,000 tons additional waste per day).  This number is predicted to reach 19,000 tons/day in 2032, with an annual growth rate of roughly 4.2%. Most of these wastes end up in landfills – in 2012, more than 90% of Qatar’s solid waste were sent to landfills although the government is intensifying its efforts to reduce this amount. This percentage is extremely high compared to many industrialized countries in Europe and Asia (e.g. Austria, Denmark, Netherlands and Japan) where less than 10% of solid waste are disposed of in landfills.  These countries have high recycling rates, have invested in technologies that convert waste into energy, and apply composting process to their organic waste. In some of these nations, as much as 40% of their wastes are composted.

Composting in Qatar

Currently, composting in Qatar is mainly done at the Domestic Solid Waste Management Centre (DSWMC) in Mesaieed, which houses the largest composting facility in the country and one of the largest in the world.  The waste that enters the plant initially goes through anaerobic fermentation, which produces biogas that can power the facility’s gas engine and generators, followed by aerobic treatment which yields the final product.

Two types of compost are generated: Grade A (compost that comes from green waste, such as yard/park trimmings, leftovers from kitchen or catering services, and wastes from markets) and Grade B (compost produced from MSW).  The plant started its operation in 2011 and when run at full capacity is able to process 750 tons of waste and produce 52 tons of Grade A compost, 377 tons of Grade B compost, liquid fertilizer which is composed of 51 tons of Grade A compost and 204 tons of Grade B compost, and 129 tons of biogas.

This is a significant and commendable development in Qatar’s implementation of its solid waste management plan, which is to reduce, reuse, recycle and recover from waste, and to avoid disposing in landfills as much as possible.  However, the large influx of workers to Qatar in the coming years as the country prepares to host the World Cup in 2022 is expected to substantially increase solid waste generation and apart from its investments in facilities like the composting plant and in DSWMC in general, the government may have to tap into the efforts of organizations and communities to implement its waste management strategy.

Future Outlook

Thankfully, several organizations recognize the importance of composting in waste management and are raising awareness on its benefits.  Qatar Green Building Council (QGBC) has been actively promoting composting through its Solid Waste Interest Group.  Last year, they were one of the implementers of the Baytna project, the first Passivhaus experiment in the country.  This project entails the construction of an energy-efficient villa and a comparative study will be performed as to how the carbon footprint of this structure would compare to a conventional villa.  The occupants of the Passivhaus villa will also be made to implement a sustainable waste management system which includes composting of food and garden waste, which is meant to lower greenhouse gas emissions compared to landfilling.

Qatar Foundation is also currently developing an integrated waste management system for the entire Education City and the Food Services group is pushing for composting to be included as a method to treat food and other organic waste.  And many may not know this but composting can be and has been done by individuals in their own backyard and can even be done indoors with the right equipment.  Katrin Scholz-Barth, previous president of SustainableQatar, a volunteer-based organization that fosters sustainable culture through awareness, skills and knowledge, is an advocate of composting and has some great resources on how to start and maintain your own composting bin as she has been doing it herself.  A simple internet search will also reveal that producing compost at home is a relatively simple process that can be achieved with minimal tools.  At present, very few families in Qatar are producing their own compost and Scholz-Barth believes there is much room for improvement.

As part of its solid waste management plan as stated in the National Development Strategy for 2011-2016, Qatar aims to maintain domestic waste generation at 1.6 kg per capita per day.  This will probably involve encouraging greater recycling and reuse efforts and the reduction of waste from its source.  It would also be worthwhile to include programs that will promote and boost composting efforts among institutions, organizations and individuals, encouraging them with the fact that apart from its capability of significant waste diversion from landfills, composting can also be an attractive source of income.

Note: The article is being republished with the permission of our collaborative partner EcoMENA. The original article can be viewed at this link.

Food Waste Management in UK

Food-Waste-UKFood waste in the United Kingdom is a matter of serious environmental, economic and social concern that has been attracting widespread attention in recent years. According to ‘Feeding the 5K’ organisation, 13,000 slices of crusts are thrown away every day by a single sandwich factory which is featured in the figure above. More recently, Tesco, one of the largest UK food retailers, has published its sustainability report admitting that the company generated 28,500 tonnes of food waste in the first six months of 2013. TESCO’s report also state that 47% of the bakery produced is wasted. In terms of GHG emissions, DEFRA estimated that food waste is associated with 20 Mt of CO2 equivalent/year, which is equivalent to 3% of the total annual GHG emissions.

Globally, 1.2 to 2 billion tonnes (30%-50%) of food produced is thrown away before it reaches a human stomach. Food waste, if conceived as a state, is responsible for 3.3 Bt-CO2 equivalent/year, which would make it the third biggest carbon emitter after China and USA. What makes food waste an even more significant issue is the substantially high demand for food which is estimated to grow 70% by 2050 due to the dramatic increase of population which is expected to reach 9.5 billion by 2075. Therefore, there is an urgent need to address food waste as a globally challenging issue which should be considered and tackled by sustainable initiatives.

A War on Food Waste

The overarching consensus to tackle the food waste issue has led to the implementation of various policies. For instance, the European Landfill Directive (1999/31/EC) set targets to reduce organic waste disposed to landfill in 2020 to 35% of that disposed in 1995 (EC 1999). More recently, the European Parliament discussed a proposal to “apply radical measures” to halve food waste by 2025 and to designate the 2014 year as “the European Year Against Food Waste”. In the light of IMechE’s report (2013), the United Nations Environment Programme (UNEP) in cooperation with FAO has launched the Save Food Initiative in an attempt to reduce food waste generated in the global scale.

In the UK, WRAP declared a war on food waste by expanding its organic waste programme in 2008 which was primarily designed to “establish the most cost-effective and environmentally sustainable ways of diverting household food waste from landfill that leads to the production of a saleable product”. DEFRA has also identified food waste as a “priority waste stream” in order to achieve better waste management performance. In addition to governmental policies, various voluntary schemes have been introduced by local authorities such as Nottingham Declaration which aims to cut local CO2 emissions 60% by 2050.

Sustainable Food Waste Management

Engineering has introduced numerous technologies to deal with food waste. Many studies have been carried out to examine the environmental and socio-economic impacts of food waste management options. This article covers the two most preferable options; anaerobic digestion and composting.

In-vessel composting (IVC) is a well-established technology which is widely used to treat food waste aerobically and convert it into a valuable fertilizer. IVC is considered a sustainable option because it helps by reducing the amount of food waste landfilled. Hence, complying with the EU regulations, and producing a saleable product avoiding the use of natural resources. IVC is considered an environmentally favourable technology compared with other conventional options (i.e. landfill and incineration). It contributes less than 0.06% to the national greenhouse gas inventories. However, considering its high energy-intensive collection activities, the overall environmental performance is “relatively poor”.

Anaerobic Digestion (AD) is a leading technology which has had a rapidly growing market over the last few years. AD is a biologically natural process in which micro-organisms anaerobically break down food waste and producing biogas which can be used for both Combined Heat & Power (CHP) and digestate that can be used as soil fertilizers or conditioners. AD has been considered as the “best option” for food waste treatment. Therefore, governmental and financial support has been given to expand AD in the UK.

AD is not only a food waste treatment technology, but also a renewable source of energy. For instance, It is expected that AD would help the UK to meet the target of supplying 15% of its energy from renewable sources by 2020. Furthermore, AD technology has the potential to boost the UK economy by providing 35,000 new jobs if the technology is adopted nationally to process food waste. This economic growth will significantly improve the quality of life among potential beneficiaries and thus all sustainability elements are considered.

Food Waste Management

The waste management hierarchy suggests that reduce, reuse and recycling should always be given preference in a typical waste management system. However, these options cannot be applied uniformly for all kinds of wastes. For examples, organic waste is quite difficult to deal with using the conventional 3R strategy.

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.

There are numerous places which are the sources of large amounts of food waste and hence a proper food-waste management strategy needs to be devised for them to make sure that either they are disposed off in a safe manner or utilized efficiently. These places include hotels, restaurants, malls, residential societies, college/school/office canteens, religious mass cooking places, airline caterers, food and meat processing industries and vegetable markets which generate organic waste of considerable quantum on a daily basis.

The anaerobic digestion technology is highly apt in dealing with the chronic problem of organic waste management in urban societies. Although the technology is commercially viable in the longer run, the high initial capital cost is a major hurdle towards its proliferation.

The onus is on the governments to create awareness and promote such technologies in a sustainable manner. At the same time, entrepreneurs, non-governmental organizations and environmental agencies should also take inspiration from successful food waste-to-energy projects in Western countries and try to set up such facilities in cities and towns.