CC BY
14
_НАУКИ О ЗЕМЛЕ / SCIENCE ABOUT THE EARTH_
DOI: https://doi.org/10.23670/IRJ.2018.72.6.020
ЭКОЛОГИЧЕСКИ БЕЗОПАСНАЯ УТИЛИЗАЦИЯ И ПЕРЕРАБОТКА МУНИЦИПАЛЬНЫХ ОТХОДОВ В ГАНЕ
Научная статья
Баах Д.1' *, Харламова М.2
1 ORCID: 0000-0003-1253-4651;
2 ORCID: 0000-0002-1032 4186;
1,2 Российский университет дружбы народов, Москва, Россия
* Корреспондирующий автор (dbaah[at]mail.ru)
Аннотация
Эта статья основана на гипотезе о том, что экологически безопасный подход к переработке и утилизации твердых бытовых отходов в Гане вполне возможен. Развивающиеся страны должны вдохновляться такими примерами, как Австрия, Германия, Швеция и Япония, где уже есть успешные стратегии для экологически безопасной утилизации твердых бытовых отходов. Несмотря на ряд проблем, есть свидетельства недавних улучшений, которые говорят в пользу того, что экологически безопасная утилизация твердых бытовых отходов возможна для таких развивающихся стран, как Гана. Это означает, что эффективность любой предлагаемой системы утилизации ТБО должна оцениваться в свете энергетических, экономических и экологических (3E) аспектов, таких как себестоимость системы, годовой объем выработанной энергии с отходов, и уровень выбросов углекислого газа (CO2).
Ключевые слова: экологически безопасное использование, муниципальные твердые отходы, переработка, энергетика, Гана.
SUSTAINABLE UTILZATION AND PROCESSING OF MUNICIPAL SOLID WASTE IN GHANA
Research article
Baah D.1' *, Kharlamova M.2
1 ORCID: 0000-0003-1253-465;
2 ORCID: 0000-0002-1032 4186;
People's Friendship University of Russia, Moscow, Russia
* Corresponding author (dbaah[at]mail.ru)
Abstract
This article is based on the hypothesis that a sustainable approach to the processing and utilization of municipal solid waste in Ghana is very much possible. Developing counties must take inspiration from countries such as Austria, Germany, Sweden, and Japan who have successful strategies in place for sustainable solid waste management. Despite several challenges, there is evidence of recent improvements which suggests that sustainable solid waste and resources management is feasible for developing countries like Ghana. This means that performance of any proposed MSW utilization system must be evaluated in light of energy, economic, and environmental (3Es) aspects, such as system net cost, annual energy generated from the waste, and the carbon dioxide (CO2) emissions of the system.
Keywords: sustainable utilization, municipal solid waste, processing, Energy, Ghana.
Introduction
Municipal solid wastes (MSWs) generation has a direct relationship with population growth process, the urbanization rate, change of lifestyle, and an increase in household income[3, P. 92-100], [4, P. 2 - 4]. It is therefore unsurprising that developing countries including Ghana are struggling with the proper management of such wastes because finding a cost effective and environmentally friendly scheme to deal with the situation has proven to be very difficult. Most of the waste generated in the country ends up in landfills but landfill sites located in all the 10regions of Ghana is considered a controlled dump rather than a properly engineered landfill.
The country of Ghana is situated at the coast of western Africa, along the Gulf of Guinea, just a few degrees north of the equator. Agriculture accounts for nearly one-quarter of GDP and employs more than half of the workforce, mainly small landholders [2, P. 1-12]. Over the last three decades, Ghana's urban population has more than tripled, rising from 4 million to nearly 14 million people, and outpacing rural population growth [2, P. 4].
Satisfying energy demand through the use of renewable energy sources is the main agenda nowadays because of the fossil fuel depletion and environmental issues. To face the future problems in waste management, as well as securing the demand of renewable energy, it is necessary to reuse the resources of solid waste in energy production. Today, there are many technologies available which makes it possible to utilize the energy potential in solid waste.
The aim of this article is to study the potential of municipal solid waste as source of renewable energy. The analysis of generation capacity and composition of municipal solid waste will be main focus to establish the amount of energy that can be recovered from Municipal solid waste and how it could be converted to usable energy forms. The article highlights the following questions:
1. What constitutes good practice in solid waste management in developing countries including Ghana?
2. How far have developing countries generally progressed with 'modernizing' their solid waste management systems?
3. What are the appropriate next steps in developing its solid waste system?
4. What makes a solid waste system sustainable?
Material and methods
This article is basically a mix of survey, literature and reports review, as well as information from stakeholders in the waste management sector. Observation is also used and the results are interpreted using graphs and tables as well as forecasting method to project the data from 2010 which was basically chosen as the base year. A strategy will be proposed considering the countries limited budget including scheme for adoption.
Results and Discussion
Increasing population alongside rapid urbanization has come with increasing challenges to waste management and the situation is fast becoming critical considering the low budget of authorities dealing with the management of waste.
The figure below summarizes the relationship between population growth and waste generation (2010 is used as the base year).
Fig. 1 - Relationship between population growth and waste generation
Note: Source World Bank.
Energy in Ghana and the potential of Bioenergy from MSW
Access to electricity, coupled with aggressive industrialization, is a key component in achieving economic and sustainable development [5, P. 3, 8]. Energy is a major requirement for economic growth and development. There is a direct link between energy use, economic growth and standard of living. [9, P. 5] In 2011 Ghana enacted a renewable energy law with the goal of increasing the country's renewable energy capacity to 10 per cent by 2020. Ghana has good potentials for developing their renewable energy sector [6, P. 94-102].The energy content of waste provides good opportunities for energy generation, as a cheap, available source, which can contribute to increasing energy access and energy consumption and reduce energy poverty in Ghana. Biogas can be utilized to power combustion engines for motive power or electricity generation, space heating, water heating and process heating. If compressed, it can replace compressed natural gas for use in vehicles, where it can fuel an internal combustion engine or fuel cells. The gas is a clean and efficient fuel which burns without smoke or smell and it's used for direct combustion in cooking or lighting application. There are several small scale biogas digesters under operation in Ghana. This is the most used technology for organic waste (mostly sewage) management in Ghana whereby the gas produced is used for cooking and lighting. [6, P. 94-102]
Therefore it is important to estimate the biogas content of municipal solid waste in order to explore the opportunities available for its utilization. There are vast biomass resources including organic waste in Ghana that have the potential for use as feedstock for biogas production to reduce the over reliance of wood fuel and fossil fuel, and to help reduce the it would reduce greenhouse gas emissions which may be affecting climate change. Ghana having the technical potential of constructing about 278,000 biogas plants, only a little over 100 biogas plants has so far been established. [11, P 1]
This article therefore calculates the biogas content of MSW as discarded from the base year which is 2010 to 2016 and summarizes the results in the table below.
BiogasMS^ = QMSW X CO.F MSW X CTS X BMPMSW.... .. (1)
Biogas potential from municipal solid waste estimated in equation (1) as the product of the amount of municipal solid waste, concentration of organic fraction, concentration of total solid and biomethane potential of the waste. An organic fraction concentration of MSW of 64% was used from Asase et al., (2009), and BMPmsw = 0.32m3 CH^kgTS (Gunaseelan, 1997). The total solid concentration (541) used was calculated based on estimates from Kemausuor et al., (2014). However, data on the annual MSW was estimated from Meiza et al., (2015) giving an annual waste for the entire population to be 4,524,760 tonnes which is approximately 4.5Mt.
Table 1 - Potential biogas content of msw (as discarded) from 2010 -2016
YEAR Quantity of waste (Mt/yr) Potential Biogas (Mm3 CH4/yr)
201 О 4.50 498.5
201 1 4.58 507.35
201 2 4.68 51 8.43
201 3 4.80 513.72
2014 4.92 545.01
201 5 5.02 556.09
201 б 5.1 7 572.71
Note: Source: Authors calculation based on estimates from Kemausuor et al., 2014).
106
Conclusion
The continuously significant increase in total quantity of MSW during the period 2010 - 2016 puts a strain on the existing MSW management system.
Most of the waste generated in Ghana ends up in landfill sites; therefore there is a need to explore the opportunities of landfill gas recovery. A sustainable approach to MSW management is very much possible in Ghana. This is because the high organic content of waste in Ghana offers a high potential for waste to energy industry to develop in Ghana especially in using anaerobic digestion but inhabitants must be made aware of the need to sort /separate their solid waste in order for this to become a sustainable option.
Energy recovery from waste can play a role in minimizing the impact of Municipal Solid Waste (MSW) on the environment and is highly feasible in Ghana considering the large amount of waste generated which are not managed efficiently. The potential contribution of waste to energy is even more important considering how critical energy is for sustainable development in Ghana. Some of the factors that justify the feasibility of energy production from MSW are the amount of MSW generated, characteristics and quality of the wastes, the type of technology used for the energy production and economic conditions (cost benefit analysis).
To ensure the sustainable function of a waste management project, factors such as technical, economic, institutional and social must be considered especially because technologies available have its advantages and disadvantages.The question that this article raises is that: Is Ghana prepared to tap into the market of renewable forms of energy and adopt utilization techniques?
Конфликт интересов Conflict of Interest
Не указан. None declared.
Список литературы / References
1. The World Bank / What a waste. A global review of solid waste management // The Urban Development Series Knowledge papers. Washington, DC, USA. - 2012. - №15. - P. 12-17
2. Ghana Statistical Service (GSS) / Population and Housing Census Report, Accra, Ghana. // Main Report. - 2012. - P. 1-12
3. Henry R K. Municipal solid waste management challenges in developing countries / R K Henry, Z Yon sheng, D. Jun // Kenyan case study. Waste management. - 2006. - №26. - P.92-100
4. Scarlet N. Evaluation of energy potential of Municipal Solid Waste from African urban areas / N .Scarlet, V. Motola, J.F. Dallemand and others // Elsevier Science Publish. - 2015. - №50. - P. 2-4
5. Wikner E. Modeling Waste to Energy systems in Kumasi, Ghana / Emma Wikner // Master thesis in Environmental and Aquatic Engineering. Department of Energy and Technology, Swedish University of Agricultural Sciences. - 2009. - P. 3& 8
6. Ofori-Boateng C. The prospects of electricity generation from municipal solid waste (MSW) in Ghana: A better waste management option / C. Ofori-Boateng, K. T. Lee, M. Mensah // Journal of Fuel Processing Technology- 2013. - № 110. - P. 94-102.
7. Kemausuor F. Assessment of Feedstock Options for Biofuels Production in Ghana / F. Kemausuor, J. O. Akowuah, E. Ofori // Journal of Sustainable Bioenergy Systems. - 2013. - № 3. - P.119-128 http://dx.doi.org/10.4236/jsbs.2013.32017
8. Miezah K. Municipal solid waste characterization and quantification as a measure towards effective waste management in Ghana / K. Miezah, K. Obiri-Dansoa, Z. Kádárc and others // Elsevier Science Publish. - 2015. - №46. - P.15-27.
9. Energy commission of Ghana (EC) / Strategic National Energy Plan 2006-2020.- P. 5
10. Murphy J. The benefits of integrated treatment of wastes for the production of energy / J. Murphy, E. McKeogh // Elsevier Science Publish. - 2006. - № 31. - P. 294-310
11. Arthur R. Biogas as a potential renewable energy source: A Ghanaian case study/ R. Arthur, M. F. Baidoo, E. Antwi // Elsevier Science Publish. - 2011. - №36. - P.1
