Composting Scenario in Qatar

The State of Qatar has one of the highest per capita waste generation rates worldwide. In 2012, Qatar generated 8,000 tons of solid waste daily (this is 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%.1  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.2 In some of these nations, as much as 40% of their wastes are composted.

What is Composting

Composting is an effective method for reducing the amount of garbage that enters landfills.  This is particularly applicable to waste streams having high organic content, which applies to most municipal solid wastes (MSW).  The process of composting is basically the breakdown of organic matter by micro and macroorganisms such as bacteria, fungi and/or earthworms in an aerobic environment.  The resulting product – compost – is rich in nutrients beneficial to plants like nitrogen, phosphorus and potassium, so it is mainly used as fertilizer and soil conditioner.  The market for compost is steadily rising thanks to the effort of many governments to promote sustainable agriculture and the increasing demand for organically grown produce.  Composting, therefore, aside from keeping organic wastes from filling up landfills, can also be an excellent source of revenue.

Composting in Qatar

At present, 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.3 

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.

Silver Lining

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.

 

References

  1. Qatar Development Bank (2013). “Qatar Solid Waste Management Phase 1 Assessment”.  Presentation during the Environment Statistics 2013 Workshop organized by the Ministry of Development Planning and Statistics
  2. Hoornweg, D. and Bhada-Tata, P. (2012). “What a Waste: A Global Review of Solid Waste Management”. USA: World Bank
  3. “World’s Largest Composting Plant in Mesaieed”. Gulf Times 23 February 2012. Accessed 27 February 2014. http://goo.gl/xcLtXa

Food Wastes Disposal Methods

Food waste is one of the most prominent waste streams across Middle East, especially in GCC region.  The mushrooming of hotels, restaurants, fast-food joints and cafeterias in the Middle East region has resulted in the generation of huge quantities of food wastes. 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 in the Middle East. 

Food waste is an untapped energy source that mostly ends up rotting in landfills, thereby releasing greenhouse gases into the atmosphere. Food waste includes organic wastes generated in hotels, restaurants, canteens, cafeterias, shopping malls and industrial parks in the form of leftover food, vegetable refuse, stale cooked and uncooked food, meat, teabags, napkins, extracted tea powder, milk products etc. It is difficult to treat or recycle food waste since it contains high levels of sodium salt and moisture, and is mixed with other waste during collection. 

Food waste can be recycled by two main pathways:

  • Composting: A treatment that breaks down biodegradable waste by naturally occurring micro-organisms with oxygen, in an enclosed vessel or tunnel or pit
  • Anaerobic digestion or biogas technology: 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.

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. Compost is organic material that can be used as a soil amendment or as a medium to grow plants. Mature compost is a stable material with a content called humus that is dark brown or black and has a soil-like, earthy smell. It is created by: combining organic wastes (e.g., yard trimmings, food wastes, manures) in proper ratios into piles, rows, or vessels; adding bulking agents (e.g., wood chips) as necessary to accelerate the breakdown of organic materials; and allowing the finished material to fully stabilize and mature through a curing process. 

Anaerobic Digestion

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. The relevance of biogas technology lies in the fact that it makes the best possible utilization of various organic wastes as a renewable source of clean energy. A biogas plant is a decentralized energy system, which can lead to self-sufficiency in heat and power needs, and at the same time reduces environmental pollution. 

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 utilized 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. 

 

Composting Guidelines for Beginners

It seems everyone is concerned about the environment and trying to reduce their “carbon footprint”.  Let us hope that this trend will continue and grow as a worldwide phenomenon.  Composting has been around for many years and is a great way to keep biodegradables out of the landfill and to reap the reward of some fabulous “black gold”.  That’s what master gardeners call compost and it’s great for improving your soil.  Plants love it. 
Check out few Rules to Remember About Composting.
  1. Layer your compost bin with dry and fresh ingredients: The best way to start a compost pile is to make yourself a bin either with wood or chicken wire.  Layering fresh grass clippings and dried leaves is a great start.
  2. Remember to turn your compost pile: As the ingredients in your compost pile start to biodegrade they will start to get hot.  To avoid your compost pile rotting and stinking you need to turn the pile to aerate it.  This addition of air into the pile will speed up the decomposition.
  3. Add water to your compost pile: Adding water will also speed up the process of scraps turning into compost.  Don’t add too much water, but if you haven’t gotten any rain in a while it’s a good idea to add some water to the pile just to encourage it along.
  4. Don’t add meat scraps to your pile: Vegetable scraps are okay to add to your compost pile, but don’t add meat scraps.  Not only do they stink as they rot, but they will attract unwanted guests like raccoons that will get into your compost bin and make a mess of it.
  5. If possible have more than one pile going: Since it takes time for raw materials to turn into compost you may want to have multiple piles going at the same time.  Once you fill up the first bin start a second one and so on.  That way you can allow the ingredient in the first pile to completely transform into compost and still have a place to keep putting your new scraps and clippings.  This also allows you to always keep a supply of compost coming for different planting seasons.
  6. Never put trash in your compost pile: Just because something says that it is recyclable it doesn’t mean that it should necessarily go into the compost bin.  For example, newspapers will compost and can be put into a compost pile, but you will want to shred the newspapers and not just toss them in the bin in a stack.  Things like plastic and tin should not be put into a compost pile, but can be recycled in other ways.
  7. Allow your compost to complete the composting process before using: It might be tempting to use your new compost in your beds as soon as it starts looking like black soil, but you need to make sure that it’s completely done composting otherwise you could be adding weed seeds into your beds and you will not be happy with the extra weeds that will pop up.
  8. Straw can be added if dried leaves are not available: Dried materials as well as green materials need to be added to a compost bin.  In the Fall you will have a huge supply of dried leaves, but what do you do if you don’t have any dried leaves?  Add straw or hay to the compost bin, but again these will often contain weed seeds so be careful to make sure they are completely composted before using them.
  9. Egg Shells and Coffee grounds are a great addition: Not only potato skins are considered kitchen scraps.  Eggshells and coffee grounds are great additions to compost piles because they add nutrients that will enhance the quality of the end product.
  10. Never put pet droppings in your compost pile: I’m sure you’ve heard that manure is great for your garden, but cow manure is cured for quite a while before used in a garden.  Pet droppings are far to hot and acidic for a home compost pile and will just make it stink.

Solid Waste Management in Saudi Arabia

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

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

Waste Management Scenario

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

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

Government Initiatives

The Saudi government is aware of the critical demand for waste management solutions, and is investing heavily in solving this problem. The 2011 national budget allocated SR 29 billion for the municipal services sector, which includes water drainage and waste disposal. The Saudi government is making concerted efforts to improve recycling and waste disposal activities.  Recently the Saudi Government approved new regulations to ensure an integrated framework for the management of municipal wastes. The Ministry of Municipal and Rural Affairs will be responsible for overseeing the tasks and responsibilties of the solid waste management system.

However, more serious efforts are required to improve waste management scenario in the Kingdom. A methodical introduction of modern waste management techniques like material recovery facilities, waste-to-energy systems and recycling infrastructure can significantly improve waste management scenario and can also generate good business opportunities. 

Conclusions

Strong legislations, financial support, public awareness, modern technologies and stakeholders’ participation should be the key in transforming Saudi Arabia into a ‘green’ nation. A strong political commitment and unflinching public support is mandatory for implementing a sustainable waste management strategy in the country. 

Analysis of a Composting Facility

The composting process is a complex interaction between the waste and the microorganisms within the waste. 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.

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. The temperature of the biomass increases due to the microbial activity and the insulation properties of the piled material. The temperature often reaches 650C to 750C within a few days and then declines slowly. This high temperature hastens the elimination of pathogens and weed seeds.

A typical composting plant consist of some or all of the following technical units: bag openers, magnetic and/or ballistic separators, sieves, shredders, mixing and homogenization equipment, turning equipment, aeration systems, bio-filters, scrubbers, control systems etc. 

Composting costs include site acquisition and development, regulatory compliance, facility operations, and marketing of the finished product. Additional requirements may include land for buffers around the compost facility, site preparation, and handling equipment such as shredders, screens, conveyors, and turners. Facilities and practice to control odors, leachate, and runoff are a critical part of any compost operation.

The cost of constructing and operating a windrow composting facility will vary from one location to another. The operating costs depend on the volume of material processed. The use of additional feed materials, such as paper and mixed municipal solid waste, will require additional capital investment and materials processing labor.

The capital costs of windrow or aerated piles are lower than in-vessel composting configuration. However, costs increase markedly when cover is required to control odors. In general, costs of windrow systems are the lowest compared to the other two techniques. The in-vessel system is more costly than other methods, mainly with respect to capital expenditures. In addition, it is more mechanized and more equipment maintenance is necessary; however, it tends to be less labor-intensive.

Overview of Composting Methods

The composting process is a complex interaction between the waste and the microorganisms within the waste. The microorganisms that carry out this process fall into three groups: bacteria, fungi, and actinomycetes. Actinomycetes 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.

Types of Composting

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 are high).

However, unlike the above two options, it is a completely odorless process making it a preferred solution in residential areas. It also has an extremely high rate of conversion, so quality of the end product is very high with rich macro and micronutrients. The end product also has the advantage that it can be dried and stored safely for a longer period of time.

 

Thermophilic Composting and its Relevance for MENA

Thermophilic composting of organic waste is getting increasing attention worldwide because of its ability to convert solid wastes into organic fertilizer within a short period of time. The system consists of an enclosed reactor laced with a microbe-enzyme cocktail. The commonly used microorganisms are naturally occurring bacillus sp., pseudomonas sp, bifidobacterium sp., lactobacillus sp., streptomyces sp., corynbacterium sp etc. Enzymes such as proteinase, keratinase, lipase and cellulose are employed to accelerate the aerobic digestion process.

Salient Features

The most important feature of thermophilic composting process is its operating temperature range of 70 – 80 °C which eliminates all pathogens and harmful bacteria present in the waste stream, and activate the thermophilic enzyme thus shortening fermentation time.

During the digestion process, complex organic waste is digested into simpler organic matter, which forms the backbone of quality organic fertilizer after 24 hours of processing in the digester. Organic waste can be of animal or plant origin such as organic fraction of MSW, slaughterhouse waste, animal manure, food wastes, vegetable and fruit market wastes etc.The end product is odor-free and pathogen-free high-quality organic fertilizer.

Acceptability in the MENA Region

The high rate of growth and consequent rise in solid waste generation in the MENA region makes it imperative on governments to make use of latest waste management technologies to manage wastes in a sustainable manner. Thermophilic composting is a promising innovation which can address a variety of solid waste management issues. A wide range of organic waste can be processed into organic fertilizer which can, in turn, be used for growing food and cash crops in the Middle East.

Organic fertilizer is important in the MENA region due to the sandy soils condition. Sandy soil has poor nutrient and water retention, which are vital for agriculture. With the use of organic fertilizer, the organic matter content will improve the fertility of soil and more sand space can be added value for sustainable farming activity.

The organic fertilizer produced can also be mixed with chemical fertilizers to produce “fortified organic fertilizer” which combines the benefits of both organic and chemical fertilizers. Such fertilizer is getting more popular because it is cheaper and environment-friendly compared to chemical fertilizers. In some countries around the MENA region, quality organic fertilizer is a scarce resource which is more expensive than chemical fertilizers.

The market adaptability of organic fertilizer allows it to be used both in organic farming and conventional farming because the quality organic fertilizer is able to bring in intangible benefits such as healthier soil which helps to lower down future fertilizing costs. This allows the producer to tap into both farming markets.

However the growth of organic farming is strongly dependent on the constant supply of organic fertilizers with consistent quality and big volume which can be ensured by introducing modern composting systems, like thermophilic composting, in the Middle East. Such systems are currently being used in Southeast Asia, Europe and North America and shall find market acceptance in MENA on account of its ability to address environmental issues, generation of attractive business opportunities and promoting entrepreneurial initiative across the region.

What is 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.

Simply speaking, vermicompost is earthworm excrement, called castings, which can improve biological, chemical, and physical properties of the soil. The chemical secretions in the earthworm’s digestive tract help break down soil and organic matter, so the castings contain more nutrients that are immediately available to plants.

How is Vermicompost Produced

A wide range of organic residues, such as straw, husk, leaves, stalks, weeds etc can be converted into vermicompost. Other potential feedstock for vermicompost production are livestock wastes, poultry litter, dairy wastes, food processing wastes, organic fraction of MSW, bagasse, digestate from biogas plants etc. 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.

There are nearly 3600 types of earthworms which are divided into burrowing and non-burrowing types. Red earthworm species, like Eisenia foetida, and are most efficient in compost making. The non-burrowing earthworms eat 10 percent soil and 90 percent organic waste materials; these convert the organic waste into vermicompost faster than the burrowing earthworms. They can tolerate temperatures ranging from 0 to 40°C but the regeneration capacity is more at 25 to 30°C and 40–45 percent moisture level in the pile. The burrowing types of earthworms come onto the soil surface only at night. These make holes in the soil up to a depth of 3.5 m and produce 5.6 kg casts by ingesting 90 percent soil and 10 percent organic waste.

A commercial vermicomposting facility in Avon, New York

The types of vermicomposting depend upon the amount of producton and composting structures. Small-scale vermicomposting is done to meet personal requirements and farmers/gardeners can harvest 5-10 tons of vermicompost annually. On the other hand, large-scale vermicomposting is done at commercial scale by recycling large quantities of organic waste in modern facilities with the production of more than hundreds of tons annually.

Applications of Vermicompost

The worm castings contain higher percentage of both macro and micronutrients than the garden compost. 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.

Vermicompost also benefits the environment by reducing the need for chemical fertilizers and decreasing the amount of waste going to landfills. Vermicompost production is trending up worldwide and it is finding increasing use especially in Western countries, Asia-Pacific and Southeast Asia.

A relatively new product from vermicomposting is vermicompost tea which is a liquid produced by extracting organic matter, microorganisms, and nutrients from vermicompost. Unlike vermicompost and compost, this tea may be applied directly to plant foliage, reportedly to enhance disease suppression. Vermicompost tea also may be applied to the soil as a supplement between compost applications to increase biological activity.

Vermicompost may be sold in bulk or bagged with a variety of compost and soil blends. Markets include home improvement centers, nurseries, landscape contractors, greenhouses, garden supply stores, grocery chains, flower shops, discount houses, and the general public.