By Masajage Edward*, Kaahwa Isaac Matthew, Dr. Agunyo Miria,
Masajage Edward graduated with a Bachelor of Science in Civil and Environmental Engineering from Uganda Christian University in 2020. He is an aspiring structural engineer and a CAD engineer for Avrateq, a visualization brand being natured by the 8M Forum
Corresponding Author: Masajage Edward
ABSTRACT
The purpose of the study was to examine the economic feasibility of applying a Material Recovery Facility to Mukono Municipality. The case study was Katikolo composting and landfilling site. The study was guided by the following specific objectives: to assess the current solid waste management status in Mukono Municipality, to perform a waste characterization study, to design an economically feasible MRF for Mukono Municipality. Mukono Municipality manages its solid waste by disposing it at Katikolo Landfill and Composting Site. The study revealed that approximately 44 tonnes/day of solid waste is received at Katikolo Landfill and Composting Site. Mukono Municipality, generates approximately 15.2 tonnes/day of this waste contributing 34.4% of the total waste received. This study further revealed that the per capita waste, generation for Mukono Municipality is estimated at 0.19kg/person/day. The individual compositions within this waste was determined as: organics 73%, paper and pulp 4.52%, glass 1.53%, metal 2.5%, plastics 9.53%, textiles 5.47%; other waste 3%. Furthermore, when compared with the WACS performed by Mukono Municipality in 2017, organics showed a negative percentage drop of 15.72%, paper and pulp showed a positive percentage gain of 2.28%, glass showed a positive gain of 10.28%, metal showed a positive gain of 1.21%. The facility design was based on the results gathered in regard to Solid Waste Management Practice and Waste Characterization from Mukono Municipality. The type of the MRF designed is a single stream/mixed waste MRF since the existing waste collection does not practise waste segregation at source and transportation. It was designed to operate for a 20-year period, processing at a maximum capacity of 15,000 tons/year. The facility was designed to have a total interior footprint area of 290sqm where the tipping floor area of 111.6sqm, sorting room of area 58.75sqm and storage room area of 120sqm. The facility will have a conveyor length of 24m, employing 26 sorters working one daily shift of seven hours/day. Economic analysis of the facility using the payback period analysis shows that the MRF will be able to repay its initial cost on investment within 14 years and will be achieved when the throughput waste received is 40TPD. The analysis further shows that at end of the operation lifetime, the MRF will achieve a net profit of 10,538,928,985 UGX on initial investment in its fourteenth year of operation. Investment into this project will yield a positive rate of return of 45.8% on the investment. This shows that the project will generate profit and yield positive gain upon initial investment. ROR analysis supports the analysis provided by payback analysis method, to show that investment into the project will be economically feasible.
1.0 INTRODUCTION
Globally, waste management is shifting from conventional landfill and recycling of both municipal and industrial waste towards waste management activities supported by integrated waste policy. Programmes involving zero waste targets and 100% diversion from landfill are increasingly noted with rising urban densities and land prices in major cities across the world (Andrews-Speed et al., 2012; EEA, 2014). The waste industry is now recognized as an underutilized ‘resource industry’ in its own right, with increasing focus on waste having inherent economic value. Formal and informal recycling activities have emerged as central to most waste management programmes in the developed world (Karani and Jewasikiewitz, 2007).
However, the waste industry in developing countries such as Uganda lags behind in implementing activities that promote zero waste targets and 100% landfill diversion from landfills. Integrated solid waste management. Katikolo Landfill and Composting Site is part of the waste management system for Mukono Municipality and its surrounding areas receiving all its municipal solid waste. Despite sustainably managing the organic fraction of the waste received through composting, Mukono Municipality still faces a challenge of sustainably managing the inorganic fraction of the solid waste it generates. Currently approximately 5% of the estimated 44 tonnes received at Katikolo is sorted to recover recyclable materials, this activity is however done by scavengers whose efficiency is determined by the level of their efforts. However, with this level of sorting and resource recovery efficiency, recyclable materials with potential economic value end up being dumped into the landfill thus reducing its existing capacity and loss of potential economic revenue to the municipality.
This project therefore seeks to assess the feasibility of a Material Recovery Facility (MRF) for Mukono Municipality hence improving sustainability of its solid waste management and solid waste recycling capacity.
Specific objectives
To assess current solid waste management status in Mukono Municipality.
To perform a waste characterization study.
To design an appropriate MRF for Mukono Municipality
2.0 METHODOLOGY
This chapter outlines the research methodology that was used to conduct the research and inform the design. It consists of geographic scope and study methodology applied to achieve the objectives of this research. It details the research design used in performing the waste characterization study and economic analysis for the MRF.
2.1 Research precedure
This section covers the different stages that were followed during the research process. It covers all the way from acquisition of information along the waste stream till the facility’s economic analysis.
2.1.1 Acquiring information along the waste stream of Mukono Municipality
This information was collected through interviews using draft questionnaire. The relevant people interviewed were; licensed waste collectors specifically for those that collect solid waste around Mukono Municipality, Mukono Municipality environmental officers, and the waste sorters at Katikolo Landfill and Composting Site.
2.1.2 Study area
The ultimate disposal of waste for Mukono Municipality is Katikolo Waste Composting Plant and Landfill, located in Katikolo Village within Mukono Town Council (MTC). The site measures about 10 acres isolated from homesteads shared between a site for landfilling and a composting site with 6 windrows. A barbed wire fence surrounds the entire site to restrict access by animals and to prevent unauthorized entry. The site itself is accessed through a gate. The site is bordered in the south, southeast and west by Katikolo wetland adjacent to Lake Victoria while to the north and east it is bordered by Katikolo Hill.
2.1.3 Waste analysis and characterization study
Waste generation data at Katikolo landfill was collected for five days from 7th January 2020 to 12th January 2020. Waste generation was determined by counting the number of trucks that brought waste on each day that the experiment was carried out. Since there is no weighbridge at Katikolo, weighbridge data from Kiteezi Landfill for different truck types was used to determine the waste transported by a particular truck. The truck plate number was also recorded in order to establish the origin of the waste, an example is shown in Table 1.
| 11/1/2020 | |
| LG 0006 129 | 5 |
| LG 0006 129 | 5 |
| UXE 126 | 3.5 |
| UG 2335 S | 40 |
| UAD 110K | 2.5 |
| UAV 645 T | 2.5 |
| Sub total | 58.5 |
| Subtotal municipality contribution | 18.5 |
| Total Average Waste received at Katikolo | |
| Total (ton/day) | 44 |
| Waste received at Katikolo from Mukono Municipality only | |
| Total (ton/day) | 15.2 |
| % contribution | 34.4 |
The waste characterization study was carried out according to the following two manuals:
ASTM – American Society for Testing and Materials – Standard Test Method for Determination of the Composition of Unprocessed Municipal Solid Waste.
UNEP/IETC – Developing Integrated Solid Waste Management Plan, Training Manual. Volume 1: Waste Characterization and Quantification with Projections for Future (2009).
2.1.4 Waste Characterization and Composition
This study focused on garbage trucks only operating within Mukono Municipality and targeted a 70% confidence level of the data collected. Therefore eight waste samples were picked in accordance with UNEP/IETC. Developing Integrated Solid Waste Management Plan, Training Manual. Eight random samples were picked at different depths of the waste heaps dumped by the garbage trucks and collected in sacks. The waste was transported to a sorting area lined with HDPE plastic sheet measuring 3m by 3m and demarcated prior to receiving of the sampled waste. The waste received at the sorting area was mixed and the quartering technique applied to reduce the waste to 100-200kg manageable samples. To obtain the sample to sort, two diagonal quarters of the quartered waste heaps was chosen and the other heap placed aside to determine the waste density. The heap chosen for sorting was done so under the researcher’s supervision into eight different categories shown in Table 2. These were weighed and their different weights recorded.
| Material category | Material subcategory |
| Organic | |
| Plastics | PET HDPE containers HDPE film PP |
| Paper | This was not sub-categorized |
| Cardboard | This was not sub-categorized |
| Glass | This was not sub-categorized |
| Metals | Ferrous Metals Non Ferrous Metals |
| Other wastes | This was not sub-categorized |
| Textiles | This was not sub-categorized |
2.1.5 Waste density
The waste density was obtained by use of a weighed container (W2) of volume V1, the waste was placed into the container and dropped from a height of 30cm to settle the waste, and its weight would then be recorded (W1) and the waste density determined from the formula
Waste density = (W1-W2) /V1.
Where:
V1 = 0.02m3
W2 = 0.7 kg
2.2 Facility Economic Analysis
2.2.1 Engineering costs
Evaluating a set of feasible alternatives requires that many engineering costs be analyzed. Examples include costs for initial investment, new construction, facility modification, general labour, parts and materials and many other. The types of costs experienced in engineering are fixed, variable and marginal costs.
2.2.2 Methods of Facility Economic Analysis
To assess the economic feasibility of carrying out an engineering project, economic analysis must be carried out. There are various methods that can be used to assess economic feasibility. To assess economic feasibility of the MRF, this research focused on two methods:
Payback period
Payback period is the period of time required for the profit or other benefits from an investment to equal the cost of the investment (Donald G. Newman, Ted G. Eschenbach, 2004).
However, payback period might in some cases give inaccurate results that may lead to the wrong decisions. Nevertheless, it does provide an estimate to when capital invested into the engineering project will be made available again such that it can be invested into other revenue generating projects. Therefore, payback period will be used to give a clearer picture of the economic feasibility of the project. It will be used together with Rate of Return (ROR) analysis method (Donald G. Newman, Ted G. Eschenbach, 2004).
Rate of return
Rate of Return (ROR) analysis is probably the most frequently used exact analysis technique in engineering projects, it is useful in comparing the financial advantages of alternative systems using the cash flow (Donald G. Newman, Ted G. Eschenbach, 2004; Ardalan, 2000). In ROR analysis, no interest rate is introduced into the calculations. Alternatively, the ROR is calculated from the cash flow and the calculated ROR compared with a preselected minimum rate of return termed simply as MARR as well (Donald G. Newman, Ted G. Eschenbach, 2004).
ROR can be determined from the formula below.
ROR = Current Value – Original value X 100
3.0 RESULTS AND DISCUSSIONS
This chapter covers the results obtained from the general research and discussions that explain the rationale of the data acquired. It covers the results obtained from the waste management situation in the scope and the facility design components.
3.1 Waste management situation in Mukono Municipality
This section covers the different situations of waste management. It covers the collection, transportation, storage, resource recovery, ultimate disposal till waste with economic value.
3.1.1 Temporary Storage
The study revealed that people temporarily store their waste in garbage bags, polythene bags, sacks, buckets and waste heaps. The garbage bags are provided by the private waste collectors. However, for those who cannot afford them, sacks and polythene bags are used. The study also revealed that all waste collectors gather unsorted waste.
3.1.2 Collection
The study revealed that waste collection is carried out under a public private partnership, five licensed waste collectors operate within the municipality while the municipality employs two tipper trucks and one tractor to collect waste within the municipality. The municipality collects waste everyday apart from Sundays while most waste collectors collect waste on Saturdays only. The study also revealed that the collection activity is carried out by males only.
3.1.3 Transportation
The study revealed that the municipality uses the following vehicles to transport waste: Mersey Ferguson tractor, FAW tipper truck. The private waste collectors use the following vehicles: Mercy Ferguson tractor, Isuzu Elfs and ISUZU Forwards and Nissan Fuso to transport the waste.
3.1.4 Resource recovery
The study revealed that metal is the most recovered material from the municipal waste during collection and transportation of the waste to Katikolo. This explains the low amounts of metal that was discovered during the waste analysis and characterization study. This is because of metals high market value. The study also revealed that plastics especially HDPE and PET containers are also recovered during transportation and collection activities.
3.1.5 Ultimate disposal
From the study, it was determined that all waste collectors ultimately dispose their waste at Katikolo Landfill and Composting Site. This site does not have a weighbridge and inspection area. Therefore, there is no control of the type of waste that comes into the site. At the site, compositing and landfilling activities take place, resource recovery is also carried out by scavengers.
3.1.6 Waste generation
Waste generation is the amount of waste produced by a community in units of volume and weight per capita per day. The study revealed that approximately 44 tonnes/day of municipality waste is received at Katikolo, Mukono Municipality generates approximately 15.2 tonnes/day of this waste contributing 34.4% of the total waste received. The per capita waste generation for Mukono Municipality was calculated as approximately 0.19kg/person/day. This was estimated with a population of 79,598 people at a population growth rate of 2.7% (UBOS, 2014).
3.1.7 Waste composition
This study was carried out in ideally the first dry season of the year in the month of January. The solid waste sorting at Katikolo resulted in eight components (illustrated in Figure 6) of waste that consisted of paper and cardboard, textile, plastics, construction and demolition waste, organics, metals, glass and other waste.
3.1.8 Waste with economic value
This section illustrates the economic value of the waste collected from the Municipality using tables 4 and 5. Table 4 shows the material buyers and cost for the materials obtained from the waste whereas Table 5 shows the revenue generated from the recycled materials.
| Material | % composition | Recovery status | Amount (kg/day) | Market prices(Shs/kg) | projected Annual revenue |
| Paper | 1.03 | Recyclable | 88.374 | 500 | UGX 16,128,255 |
| Cardboard | 3.49 | Recyclable | 299.442 | 200 | UGX 21,859,266 |
| Glass | 1.53 | Recyclable | 131.274 | 0 | UGX 0 |
| Ferrous metal | 2.34 | Recyclable | 200.772 | 1000 | UGX 73,281,780 |
| Non Ferrous metal | 0.16 | Recyclable | 13.728 | 3800 | UGX 19,040,736 |
| LDPE | 0.59 | Recyclable | 50.622 | 150 | UGX 2,771,555 |
| LLDPE | 1.98 | Non-Recyclable | 169.884 | 0 | UGX 0 |
| HDPE containers | 2.38 | Recyclable | 204.204 | 600 | UGX 44,720,676 |
| HDPE film | 2.22 | Recyclable | 190.476 | 600 | UGX 41,714,244 |
| PET | 1.15 | Recyclable | 98.67 | 400 | UGX 14,405,820 |
| PP | 1.21 | Recyclable | 103.818 | 800 | UGX 30,314,856 |
| Textile | 5.47 | Non-recyclable | 469.326 | 0 | UGX 0 |
| Organics | 72.96 | Recyclable | 8430.09024 | 100 | UGX 307,698,294 |
| Construction & Demolition waste | 0 | Non-recyclable | 0 | 0 | UGX 0 |
| Other waste | 3.49 | Non-recyclable | 499.07 | 0 | UGX 0 |
| Total | 100 | 10949.75024 | UGX 571,935,481 |
| Materials | Buyers | Prices /Kg (UGX) | Time of collection |
| Plastic bottles | Rwenzori (Coca Cola) | 250 | Every Saturday |
| LPDE | Community | 150 | Every Saturday |
| Metallic scraps | Steel and Tube Industry | 1000 | Every Saturday |
| Sacks (PP) | Linda Recycling Industry | 250 | Every Saturday |
| Cardboard | Global Paper Company | 200 | Every Saturday |
| HDPE containers | Rwenzori (Coca Cola) | 600 | Every Saturday |
| HDPE Film | Rwenzori (Coca Cola) | 600 | Every Saturday |
| Compost | Farmers | 100 | Every Day |
| Milk Packs (1 liter) | Fishermen | 100 | Every Saturday |
| PP | Community | 800 | Every Saturday |
NB: The organic material loses mass by about 19.2% during decomposition
3.1.9 Recycling Potential
The recycling potential was estimated based on a materials revenue generation. Recycling potential for the different materials is a function of it’s composition in the waste, the estimated waste received at Katikolo and the market price of the material. The formula used to calculate recycling potential was;
Recycling potential = (%waste composition*Mukono Municipality waste generation*market value).
From Figure 8, organics showed the highest recycling potential, LDPE plastic had the lowest recycling potential which justifies its low level of resource recovery activity at Katikolo. The economic value of Organic waste can created by processed it into compost, paper and cardboards economic value can be derived by drying it and selling it to paper recyclers, PET, PP and HDPE plastics can be shredded into resin, baled (compacted) or sold in their original form to plastic recyclers. HDPE and LDPE film can baled and sold to recyclers, Metals are sold as scrap to recyclers and don’t necessarily need to go through any processing.
3.2 Material Recovery Facility Design
This section explains the design and operation of the material recovery facility all the way from the process to the type.
3.2.1 Flow process
The preliminary design was based on the results gathered in regard to Solid Waste Management practice and waste characterization from Mukono Municipality.
3.2.2 Type of the Material Recovery Facility
The type of the MRF is a single stream/mixed waste MRF since the existing system basically encounters collection of mixed waste from the customers. The sorting system is mostly manual since there is labour available at the site.
The flow process at the Material Recovery Facility is illustrated in Figure 9 and summarised below.
It consists of
a) Registration
This is where the vehicle trucks are registered before dumping the waste. Here the management can check if the truck bringing in the waste is from a registered collector or not.
b) Inspection
This is where bulk materials are assorted, weighed and then taken to storage. Such materials may include furniture, large scrap materials, market residue that are homogenous, and others.
3.3 Design capacity
The facility is considered to be designed for a 20-year period, thereby considering a projected population for a 20-year period from the current population. So considering a constant population growth rate, waste generation and waste generation rate, the projected waste situation is illustrated in Table 6;
| Current situation | Projected situation | ||
| Population 2014 census (people) | 69,671 | Projected Population (People) | 145876 |
| Population growth rate (%) | 3.0 | Amount of waste generated in 2040(kg) | 65,108 |
| Current population (people) | 80,768 | Additional amount of waste (kg) | 11527.39066 |
| Waste generation (tons/day) | 14.3 | Additional amount of waste (ton) | 11.52739066 |
| Waste generation rate (kg/day/person) | 0.18 | Above amount In terms of truck capacity | 2.5*(3)+1*(5) |
Assumptions considered include:
a) Constant waste generation rate of 0.18 kg/person/day;
b) Constant population growth rate of 3%;
c) The same capacity of trucks are used;
d) There is no change in waste composition.
This meant that the trucks wouldl be taking two trips per day in the next 20 years. So assuming that all trucks that collect waste from Mukono Municipality will be taking 2 trips/day; Table 7 shows the weights expected from the trucks as per the consindered assumptions.
| Vehicle | weight (tonnes) | Two trips Weight (tonnes/day) | Two trips Weight (tonnes/2 days) |
| Municipal truck (Fuso Nissan) | 5 | 10 | 20 |
| Municipal truck | 4.5 | 9 | 18 |
| Waste masters (Elf) | 2.5 | 5 | 10 |
| Asante Waste collectors (Elf) | 2.5 | 5 | 10 |
| Municipal tractor (Mercy Ferguson) | 3.5 | 7 | 14 |
| Waste masters (Elf) | 2.5 | 5 | 10 |
| Total | 20.5 | 41 | 82 |
3.4 Summary of all the components
This section expounds on the components considered during the design process are summarised and illustrated in Table 11 showing components like capacity, lifespan, sorting types, number of sorters and much more.
| Design Components | Details |
| Design Waste capacity | 15,000 tons per year |
| Design Life | 20 years |
| Sorting types | Mostly manual |
| Tipping floor dimension (m2) | 57.64 (from the drawing) |
| Total conveyor length (m) | 32.5 m |
| Sorting room (m2) | 87.5 |
| Number of sorters | 26 |
| Sorting rate (tonnes/person/hr) | 0.250 |
| Number of shifts | 1 |
| Number of working hours (hrs) | 7 |
| Storage room area (m2) | 240 |
3.5 Architectural Design Drawing
After consideration of the different design parameters, an architectural design (shown in Figure 10 and Figure 11) was proposed illustrating how the different design components would fit into one structure.
3.6 Cost estimating
To perform cost estimating, rough cost estimating was used. Cost estimates were derived from EPA Handbook for MRF design for Municipalities, Material Recovery Facility Toll kit by Asian Development Bank, quotations from equipment vendors in Uganda and Alibaba e-commerce platform.
Capital, operation and maintenance, collection, and disposal costs comprise the total costs of the MRF. Capital costs will include the construction, equipment and equipment installation costs. The construction costs include the costs associated with site work and structure works.
The major O&M cost components include the following:
1) Salaries for operation and administration.
2) Electricity and water bills
3) Fuel and oil consumption
4) Equipment and facility maintenance
Capital cost
Capital cost consists of construction, land acquisition, engineering and equipment cost, as expressed in the equation below.
Capital Cost = Construction cost + Equipment cost + Engineering cost
Capital Cost = 4,082,442,258 + 2,736,985,336 + 408,244,226
Capital Cost = 7,227,671,820 UGX
Annual operating cost
Operating cost is the total cost of labour, maintenance of equipment and utilities cost for processing material.
Operating Cost = Labour cost + Maintenance cost + Utilities Cost
Operating Cost = 96,690,000 + 95,480,350 + 144,248,000 + 8,234,400 + 361,383,591
Operating Cost = 706,036,341 UGX/year
3.7 Economic Analysis
The facility is designed to handle 80 tonnes of waste per day. However, the current amount of waste received at Katikolo is 15.25 tonnes per day. Economic analysis therefore will be performed for different case scenarios that involve the amount of waste that could be gradually be received before it starts to operate at its maximum design capacity (shown in Table 12). The different case scenarios assessed will be the current capacity, 25%, 50%, 75% and 100% of the design capacity.
| Waste generation (tons/day) | 15 (current) | 20 (25%) | 40 (50%) | 60 (75%) | 80 (100%) |
| Gross Annual revenue (UGX) | 468,952,332 | 1,044,301,500 | 2,088,603,000 | 3,132,904,500 | 4,177,206,000 |
| Annual Operating costs (UGX) | 706,036,341 | 706,036,341 | 706,036,341 | 706,036,341 | 706,036,341 |
| Net Annual revenue (UGX) | -237,084,009 | 338,256,159 | 1,382,566,659 | 2,426,868,159 | 3,471,169,659 |
3.7.1 Payback Period
Payback period analysis shows that the MRF will be able to repay its initial cost on investment within 14 years. This will be achieved when the throughput waste received is 40TPD. At the end of the operation life time, the MRF achieves net profit on investment in its fourteenth year of operation, generating a profit of 10,538,928,985 UGX at the end of its design life.
3.7.2 Rate of return Analysis
Rate of Return can be calculated from the formula below.
ROR = (Current Value – Original value X 100)/Original Value
Where:
Current Value = Current value of Investment. Capital appreciation of the structure will not be used in analysis and only the revenues from the investment will be considered.
Original Value of investment: Value of Investment. Capital investment is considered.
ROR = (8,568,065,859 – 7,227,671,820 X 100)/7,227,671,820
ROR = 18.54%
Therefore, investment into this project will yield a rate of return of 18% on the investment. Furthermore, the projected ROR will be higher than the average 7% ROR for public and private projects in Uganda by 11.54%.
4.0 CONCLUSION AND RECOMMENDATION
In conclusion, we have been able to achieve all our objectives The design was in accordance with Material Recovery Facilities Process Model published by Research Triangle Institute in partnership with and North Carolina State University. Economic Analysis on the facility was performed in accordance with EPA Handbook for design of MRF for municipalities and Material Recovery Facility Toolkit by Asian Development Bank. Economic analysis revealed that investment into such a facility will be economically profitable and beneficial to Mukono Municipality generating revenue of UGX10,538,928,985 within its years of operation. We therefore recommend for further research on cheaper local methods of sorting, feasibility of further sorting of organic material categories into wet fiber with low calorific value such as food remains and dry fiber with high caloric value and exploring the possibility of manufacturing the machinery locally in the country under the Uganda Industrial Research Institute.
REFERENCES
A.Komakech, N. Banadda, J.Kinobe, et al. (2014) Characterization of municipal waste in Kampala, Uganda. Characterization of municipal waste in Kampala, Uganda.
Asian Development Bank. (2013) Materials Recovery Facility Tool Kit.
ASTM D 5231-92 (2003) ‘Standard Test Method for Determination of the Composition of Unprocessed Municipal Solid Waste
Donald G. Newman, Ted G. Eschenbach, J. P. L. (2004) ENGINEERING ECONOMIC ANALYSIS. OXFORD UNIVERISTY PRESS.
Nishtala, S. and Solano-mora, E. (1997) Description of the Material Recovery Facilities Process Model Design , Cost , and Life-Cycle Inventory.
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