An Introduction to Composting

The composting process is a complex interaction between organic waste and microorganisms. The microorganisms that carry out this process fall into three groups: bacteria, fungi, and actinomycetesActinomycetes are a form of fungi-like bacteria that break down organic matter. The first stage of the biological activity is the consumption of easily available sugars by bacteria, which causes a fast rise in temperature. The second stage involves bacteria and actinomycetes that cause cellulose breakdown. The last stage is concerned with the breakdown of the tougher lignins by fungi.

Central solutions are exemplified by low-cost composting without forced aeration, and technologically more advanced systems with forced aeration and temperature feedback. Central composting plants are capable of handling more than 100,000 tons of biodegradable waste per year, but typically the plant size is about 10,000 to 30,000 tons per year. Biodegradable wastes must be separated prior to composting: Only pure foodwaste, garden waste, wood chips, and to some extent paper are suitable for producing good-quality compost.

Composting Equipment

The composting plants consist of some or all of the following technical units: bag openers, magnetic and/or ballistic separators, screeners (sieves), shredders, mixing and homogenization equipment, turning equipment, irrigation systems, aeration systems, draining systems, bio-filters, scrubbers, control systems, and steering systems. The composting process occurs when biodegradable waste is piled together with a structure allowing for oxygen diffusion and with a dry matter content suiting microbial growth.

Biodegradable wastes must be separated prior to composting: Only pure food waste, garden waste, wood chips, and to some extent paper are suitable for producing good-quality compost.The temperature of the biomass increases due to the microbial activity and the insulation properties of the piled material. The temperature often reaches 65 to 75 degrees C within few days and then declines slowly. This high temperature hastens the elimination of pathogens and weed seeds.

Composting Methodologies

The methodology of composting can be categorized into three major segments—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. The compost so formed may not be completely converted and may include aggregated masses.

Aerobic composting is the process by which organic wastes are converted into compost or manure in presence of air and can be of different types. The most common is 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 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 involves use of earthworms as natural and versatile bioreactors for the process of conversion. It is carried out in specially designed pits where earthworm culture also needs to be done. Vermicomposting is a precision-based option and requires overseeing of work by an expert. It is also a more expensive option (O&M costs especially are high).

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 in South Asia

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 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.

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. In case of electronic wastes, it can be sent to a Certified Electronics Recycling and Disposal firm.

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.

Solid Waste Management in Pakistan

Karachi-Garbage-DumpSolid 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.

Contributing Factors

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.

References

http://www.aljazeera.com/indepth/features/2014/08/solid-waste-pakistan-karachi-2014867512833362.html

http://www.iamcivilengineer.com/2014/04/solid-waste-disposal-and-collection.html

http://www.aljazeera.com/indepth/features/2014/08/solid-waste-pakistan-karachi-2014867512833362.html

http://www.iamcivilengineer.com/2014/04/solid-waste-disposal-and-collection.html

http://www.lwmc.com.pk/about-us.php

http://www.unep.org/ietc/Portals/136/Events/ISWM%20GPWM%20Asia%20Pacific%20Workshop/Pakistan_Presentation.pdf

http://www.dawn.com/news/1081689

http://www.lwmc.com.pk/waste-to-energy.php

Waste Management in Food Processing Industry

Food processing industry around the world is making serious efforts to minimize by-products, compost organic waste, recycle processing and packaging materials, and save energy and water. The three R’s of waste management – Reduce, Reuse and Recycle – can help food manufacturers in reducing the amount of waste sent to landfill and reusing waste.

EPA’s Food Recovery Hierarchy

EPA’s Food Recovery Hierarchy is an excellent resource to follow for food processors and beverage producers as it provides the guidance to start a program that will provide the most benefits for the environment, society and the food manufacturer.

Notably, landfill is the least favored disposal option for waste generated in food and beverage producers worldwide. There are sustainable, effective and profitable waste management options including:

  • making animal feed,
  • composting to create nutrient-rich fertilizer,
  • anaerobic digestion to produce energy-rich biogas,
  • recycling/reusing waste for utilization by other industries,
  • feeding surplus food to needy people

Waste Management Options

Food manufacturers has a unique problem – excess product usually has a relatively short shelf life while most of the waste is organic in nature. Food waste created during the production process can be turned into animal feed and sold to goat farms, chicken farms etc. As far as WWTP sludge is concerned, top food manufacturers are recycling/reusing it through land application, anaerobic digestion and composting alternatives.

Organic waste at any food processing plant can be composted in a modern in-vessel composting and the resultant fertilizer can be used for in-house landscaping or sold as organic fertilizer as attractive prices.

Another plausible way of managing organic waste at the food manufacturing plant is to biologically degrade it in an anaerobic digester leading to the formation of energy-rich biogas and digestate. Biogas can be used as a heating fuel in the plant itself or converted into electricity by using a CHP unit while digestate can be used as a soil conditioner. Biogas can also be converted into biomethane or bio-CNG for its use as vehicle fuel.

Items such as cardboard, clean plastic, metal and paper are all commodities that can be sold to recyclers Lots of cardboard boxes are used by food manufacturers for supplies which can be broken down into flat pieces and sold to recyclers.

Cardboard boxes can also be reused to temporarily store chip packages before putting them into retail distribution boxes. Packaging can be separated in-house and recovered using “jet shredder” waste technologies which separate film, carton and foodstuffs, all of which can then be recycled separately.

Organizing a Zero-Landfill Program

How do you develop a plan to create a zero-landfill or zero waste program in food and beverage producing company? The best way to begin is to start at a small-level and doing what you can. Perfect those programs and set goals each year to improve. Creation of a core team is an essential step in order to explore different ways to reduce waste, energy and utilities.

Measuring different waste streams and setting a benchmark is the initial step in the zero-landfill program. Once the data has been collected, we should break these numbers down into categories, according to the EPA’s Food Recovery Challenge and identify the potential opportunities.

For example, inorganic materials can be categorized based on their end lives (reuse, recycle or landfill).  The food and beverage industry should perform a waste sort exercise (or dumpster dive) to identify its key streams.

Nestlé USA – A Case Study

In April 2015, Nestlé USA announced all 23 of its facilities were landfill free. As part of its sustainability effort, Nestlé USA is continually looking for new ways to reuse, recycle and recover energy, such as composting, recycling, energy production and the provision of safe products for animal feed, when disposing of manufacturing by-products.

Employees also work to minimize by-products and engage in recycling programs and partnerships with credible waste vendors that dispose of manufacturing by-products in line with Nestlé’s environmental sustainability guidelines and standards. All Nestlé facilities employ ISO 14001-certified environmental management systems to minimize their environmental impact.

Utilization of Date Palm Biomass

Date palm trees produce huge amount of agricultural wastes in the form of dry leaves, stems, pits, seeds etc. A typical date tree can generate as much as 20 kilograms of dry leaves per annum while date pits account for almost 10 percent of date fruits.

date-wastes

Date palm biomass is found in large quantities across the Middle East

Date palm is considered a renewable natural resource because it can be replaced in a relatively short period of time. It takes 4 to 8 years for date palms to bear fruit after planting, and 7 to 10 years to produce viable yields for commercial harvest. Usually date palm wastes are burned in farms or disposed in landfills which cause environmental pollution in dates-producing nations.

The major constituents of date palm biomass are cellulose, hemicelluloses and lignin. In addition, date palm has high volatile solids content and low moisture content. These factors make date palm residues an excellent biomass resource in date-palm producing nations.

Date palm biomass is an excellent resource for charcoal production in Middle East

A wide range of physico-chemical, thermal and biochemical technologies exists for sustainable utilization of date palm biomass. Apart from charcoal production and energy conversion (using technologies like combustion and gasification), below are few ways for utilization of date palm wastes:

Conversion into fuel pellets or briquettes

Biomass pellets are a popular type of alternative fuel (analogous to coal), generally made from wood wastes and agricultural biomass. The biomass pelletization process consists of multiple steps including pre-treatment, pelletization and post-treatment of biomass wastes. Biomass pellets can be used as a coal replacement in power plant, industries and other application.

Conversion into energy-rich products

Biomass pyrolysis is the thermal decomposition of date palm biomass occurring in the absence of oxygen. The products of biomass pyrolysis include biochar, bio-oil and gases including methane, hydrogen, carbon monoxide, and carbon dioxide.

Depending on the thermal environment and the final temperature, pyrolysis will yield mainly biochar at low temperatures, less than 450 0C, when the heating rate is quite slow, and mainly gases at high temperatures, greater than 800 0C, with rapid heating rates. At an intermediate temperature and under relatively high heating rates, the main product is bio-oil.

Bio-oil can be upgraded to either a special engine fuel or through gasification processes to a syngas which can then be processed into biofuels. Bio-oil is particularly attractive for co-firing because it can be more readily handled and burned than solid fuel and is cheaper to transport and store.

Conversion into biofertilizer

Composting is the most popular method for biological decomposition of organic wastes. Date palm waste has around 80% organic content which makes it very well-suited for the composting process. Commercial-scale composting of date palm wastes can be carried out by using the traditional windrow method or a more advanced method like vermicomposting.

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.

Medical 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 environmental 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.