Assessment of the pathways, receptors, and effects of the relevant pollutants from both (landfill sites and incineration) disposal methods
The primary pathway for environmental pollution from burning waste and landfills is the emission of carbon footprints into the atmosphere. Most of the substances are detectable despite some being in low concentrations. They exist in the form of particulate and gaseous emissions from waste combustion. The pollutants affect water, air, and land, eventually affecting the environment. Other receptors include humans, animal dispersal, and air conditioning ducts (Stones, 2016, p. 1). Pollutants emitted through incineration include metals and other non-combustible substances. Acid gases and resultants of partial combustion also form a significant percentage of contaminants such as carbon, sulphur, and nitrogen.
The pollutants are divided among the particulate and gas phases of the mass emissions from a burning facility. Some contaminants are emitted from landfills yet do not necessarily have to be burned. For instance, methane can be emitted from landfills when animal and human waste is disposed of and decomposes. As pollutants from incineration and landfills disperse into the atmosphere, individuals within and around the facility or site are directly exposed by breathing. As receptors, individuals, animals, aquatic life, and birds are affected directly by consuming water and food adulterated by pollutant deposits on vegetation and soil (National Research Council, 2000, p. 1). Other creatures and humans can be exposed through various environmental pathways after contaminants disperse a considerable distance in the atmosphere. The pollutants undergo numerous physical and chemical transformations.
Landfills are essential for the proper disposal of solid waste. They reduce the volume of solid waste discharged into the environment (Vasarhelyi, 2021, p.1). When done correctly, landfills help minimize disease transmission while keeping communities clean. Despite being a societal necessity, landfills present social and environmental impacts. The most disturbing concern about landfills is the release of methane gas. The decomposition of organic mass generates methane gas. According to Vasarhelyi (2021, p. 1), methane is about 80 times more efficient in absorbing solar heat than carbon dioxide. As such, it is among the most potent greenhouse emission, contributing significantly to global warming. Landfills also generate carbon dioxide and water vapor. There are also some considerable amounts of nitrogen and hydrogen. The gases contribute to global warming by creating fog if not controlled.
From a social perspective, landfills are a risk to the well-being of people living near or working in landfills. Vasarhelyi (2021) indicates that the risk of congenital deformity is as high as 12 percent in New York. Infants born and grow within a radius of one mile from a harmful landfill site. Giant landfills tend to reduce the value of adjacent land by as much as 13 percent. Smaller landfills lessen the value by approximately 2.5 percent. Uncontrolled landfills increase the risk of smoke, bad smell, noise, and bugs in the surrounding community. Often, low-income and minority communities are more likely to be affected by incineration landfill pollution. The rationale is that such areas lack resources to oppose the development of landfills and incineration facilities. Low-income communities need more influence to fight the development of such facilities in their locations.
The incineration of solid waste for making electricity is publicized as a means of decreasing carbon footprints from waste treatment. In recent decades, energy production from waste has been touted as a substitute for disposing of waste in landfills. Landfills are increasingly becoming full. Incineration for electricity generation would facilitate the reduction of waste sent to landfills. Further, the dump would reduce the need for fossil fuels in traditional power generation facilities (Client Earth, 2021, p. 1). Local authorities have committed to constructing waste incineration in the UK for power generation. Nevertheless, waste incineration cannot be regarded as a low-carbon or green energy source, particularly in the short term.
A report commissioned by Eunomia Research and Consulting focused on the short- and long-term implications of waste incineration on air quality and climate in the UK. The report indicates that burning waste for power generation will produce more carbon in the UK by 2035 than landfilling (Client Earth, 2021, p. 1). It will also be a primary source of poisonous air pollution. As people continue drowning the world with plastics, waste burning will progressively be touted as the more accessible alternative. We must acknowledge that waste does not simply disappear in a gust of smoke. The more plastics and waste are incinerated either conventionally, or for power generation, the more health and ecosystems will continue suffering.
Evaluation of the effectiveness of the pollution control measures used to minimize the effects of the most significant pollutants released from landfill sites and incineration according to the best available techniques (BAT)
Inherently, waste disposed of in dumpsites is exposed to animal consumption. The failure to enclose the dumpsites persists despite transferring the dumped waste from city streets using trucks to avoid animals feeding from the garbage due to the risk of spreading diseases and the animals becoming sick. Further, the threat persists since the dumpsites are not covered to stop birds from flying in. Therefore, we look at the challenge of landfills from a critical thinking perspective regarding its effect, regardless of the method utilized for waste disposal. The rationale is that even if the dumpsite is enclosed, the possibility of wildlife feeding from the waste is high, exposing animals and the ecosystem to pollution.
Whereas landfills facilitate maintaining clean communities, they also present a grave risk to the health of individuals and the environment. Incineration facilities and open landfills are mainly located in minority and low-income communities. They are not bothered much about the effects of dumping, such as pollution of water, air, and land (Iraguha et al., 2012, p. 2). Typically, open landfills generate smoke, poisonous gases, and particulates because of partial combustion. Due to increased consumption due to increased income and enhanced lifestyle, urban centers and metropolitans will increasingly face the vast challenges of solid waste management.
In minimizing the effects of pollutants from incineration, the most common technique is the settling chamber. Incinerators typically release fly ash into the atmosphere. A colossal chamber is installed between the stack breeching and the furnace. The vent gases decelerate, allowing particulate matter to settle (Lenehan, 1962, p. 414). However, the chambers comprise of applied lower limit of particulate size separation. Baffles are utilized in the chambers to even out the gas velocities to improve separation. The cheap maintenance cost of settling chambers is counterbalanced by their colossal sizes, increased installation cost, and minimal fly ash collection capacity.
The other control measure for incineration contaminants is the use of scrubbers. The most simplified kind is the water curtain. Here, water sprays are directed in configurations to attain optimal contact with the emitted gases Lenehan, 1962, p. 415). The jets can be fixed in the settling chamber or extraordinary chambers. The jets are organized to come into contact with the maximum possible ash. The ash is sprayed and washed into the scrubber discharge.
The use of precipitators is another control measure utilized in incineration facilities. It can eliminate fine particles with almost 100 percent efficacy (Lenehan, 1962, p. 417). The pressure drop constraint is extremely low. The precipitators are capable of operating at high temperatures. Nevertheless, the increasing concern for public health and environmental pollution makes the control measures inadequate in the modern world. In justifying this, we point to various literature demonstrating the need for more advanced methods to eliminate solid waste.
According to Abubakar et al. (2022, p. 2), the global population is projected to rise to 8 billion by 2025. By 2050, the population will be about 9.3 billion (Abubakar et al. 2022, p. 2). About 70 percent of this population will be living in cities. In developing economies, the municipal authorities only collect 50 to 80 percent of generated waste. This is after spending between 20 and 50 percent of the allocated financial resources on the collection and transportation of garbage (Abubakar et al., 2022, p. 2).
Furthermore, most emerging economies collect as little as 10 percent of solid waste produced in metropolitan areas, contributing to ecological and public health risks. In such places, the receptors of the pollutants and contaminants encounter increased incidents of diarrhea and severe respiratory infections. Irrespective of the method used to eliminate solid waste, incineration, or landfills, populations living close to the facilities and landfills are prone to the implications, particularly near open garbage dumps and uncontrolled incineration facilities.
Contemporary, some cities and urban areas still utilize poorly managed incineration facilities or obsolete methods and informal unrestrained dumping and open-air waste incineration (Abubakar et al., 2022, p. 2). These best available techniques (BAT) are less effective than municipal authorities have touted them. The methods affect minority and poor communities living near disposal sites. The methods present numerous sustainability issues, including resource exhaustion, ecosystem pollution, and public health challenges. The techniques contribute to the spread of infectious diseases.
Waste management approaches in Kigali, Rwanda.
The city of Kigali is the capital of Rwanda. The country is landlocked and located in eastern/central Africa. Uganda, Tanzania, Burundi, and DRC border the country. The capital hosts about 10% of Rwanda’s population (Kabera, 2019, 1). Kigali is increasingly urbanizing and experiencing robust financial growth. With this comes an increased amount of solid waste. Evidence shows that despite the city generating over 800 tons of garbage, only about 300 tons are collected and delivered to dumping sites daily (Rajashekar, Bowers, and Gatoni, 2019, p. 12). Empirically, the waste will continue increasing as the population grows. There is notable substandard solid waste management in Kigali, despite the city being among the cleanest among emerging economies. The city’s central business district is always sparkling clean, with a well-designed landscape with flowers and trees. According to the capital’s authorities, over 90 percent of the residents have access to clean water and toilets. This notwithstanding the proper solid waste disposal methods remains the conventional landfills and waste burning in open spaces.
Figure 1: Solid waste management in Kigali City
The city managers assert that the practices employed in managing waste impede sustainable development. The country’s Vision 2020 blueprint emphasizes solid waste management. The authorities highlight the need for the whole city to be serviced by solid waste plants for households to improve their waste management. The blueprint highlights the requisite need for pursuing a ‘green economy. It provides for the need to modernize urban and rural households. The country’s legal and policy documents highlight the significance of solid waste management principles. These include the Waste Hierarchy. This is the basis for waste management reduction and the polluter-pays-concept. The policy requires waste producers to recompense for getting environmental implications. The laws articulate the procedures of hygienic landfills and landfill management protocols. The idea is the protection against leachate and unnecessary accumulation of hazardous landfill gases.
The Rwandese government has set numerous goals to be achieved at the national and city level. The goals are targeted at the improvement of waste system perspectives. These include waste production and optimization of access to waste collection. The legislation also stipulates improved waste management removal and increasing incentives for waste management. Irrespective of the notable accomplishments and determination to realize enhanced waste management, Kigali’s capacity to deal with existing and future population increase needs to be more specific. The city’s authority has always strived to improve waste disposal systems. This is done via public-private partnerships. However, a reasonable gap exists in comprehending how the overall waste disposal functions. There are gaps in how waste managers, collectors, disposers, and recyclers synergize. Numerous pieces of research highlight existing and future pollution control strategies.
Proposal for waste management strategy
Kigali’s waste management needs to be more cohesive. The requisite activities are regulated by municipal management through various organizations. The organizations deal with the environment and utilities management. They also handle water and sanitation as well as local governance. Whereas the city authorities play a significant role in the delivery of waste management services, the role does not reflect the municipal’s coordination capacity or resources in the delivery of new projects or strategies.
Considering the current best available technique fills and waste incineration, a more sustainable waste management method should prioritize techniques such as minimization of waste generation, classifying of solid waste, recycling, reusing, and recovery of energy as opposed to the conventional landfilling practices, open dumpsites, and open burning (Kabera and Nishimiwe, 2019, p. 4). The technique is increasingly becoming popular despite being in its early phases. The approach is more inclusive and ecologic-friendly. It has fewer environmental and human health effects than conventional practices. Given the ineffectiveness of the various pollution control measures utilized to minimize the impact of the most notable emissions from incineration and landfills, players must consider this effective alternative for dealing with solid waste.
In conclusion, reduction, reuse, and recycling are proper waste reduction techniques. Typically, there will always be some to be handled. Both landfill and incineration are techniques for ridding of solid waste. Although this study argues that incineration is the better option, we clarify that dumps are desirable in some circumstances. Among the reasons that landfills are considered beneficial is due to their affordability where land is vast. Incineration of waste requires expensive infrastructure. The staff managing the facility must receive considerable training. Landfills do not require sophisticated infrastructure. The method is also convenient, especially in developing economies that need more technical and infrastructural ability. Such countries focus on other matters as the provision of services.
Nevertheless, incineration remains the most appropriate mode of solid waste disposal. In most countries, incineration is the most preferred means of waste disposal. The rationale for choosing incineration is due to several factors. The first is energy production. Developed economies such as the US, UK, and Scandinavia have invested heavily in researching the worth of waste as a means of fuel feedstock (raw material for supplying manufacturing or machine process). For example, Sweden delivers as much as 8% of the country’s heating energy from incinerated waste.
Second, incineration has a high prospect of minimizing waste. The technique can reduce the diversion of solid waste to landfill by as much as 95%, making it an appropriate means of handling solid waste. The method reduces the need to carry solid waste to different landfill locations. The method reduces the probable carbon footprint involved in waste disposal. Third, incineration requires less space compared to landfills. Smaller countries with limited land have little space to create dumps. The burning of solid waste is among the solutions to this challenge. For instance, the technique is utilized in Japan’s small but populated island. Fourth, the method reduces the formation of methane generated by organic materials deposited in landfills. Once the waste is left to decompose in landfills, it causes considerable volumes of methane. Methane is not considered desirable as it contributes to greenhouse gases.
Reflection on module exercises
During this module, one of the assignments was to visit three different sites where air pollution is generated (source). We visited a construction site, with the pollutant being dust particles. We noted that the dust particles originated from dolomite, marble, limestone, cement, and gypsum. Dust particles are particulate matter that is easily blown and dispersed by wind. Dust particles are generated due to cutting different materials, such as wood and bricks. This silica dust combines with other particulates at the site. We realized that equipment and machines such as mixers and earth movers facilitating different activities further compound the dust problem. Wood dust produced from sawing also mixes with other dust particles. The pathway of all these types of particulate matter is air, exposing the workforce at the site and the surrounding communities to different diseases and respiratory infections. An individual may sneeze, cough, sore eyes, lung swells, asthma, tonsillitis, and pharyngitis (Habybabady et al., 2018, pp. 77). The dust may cause lung function impairment. Those exposed to construction site dust are likely to develop lung diseases.
The other pollution we visited was the bus station. Here, we noted that there was dust as well as carbon dioxide emitted through exhausts. The individuals who work at the bus station are exposed to respiratory infections. Vehicular emissions are greenhouse hazardous gases. Considering the many vehicles that ply the bus station daily, the effect of the emission affects those around. The gases cause damage to the ozone layer. The result is the increment of atmospheric pressure, culminating in global warming. The receptors of vehicular emissions include humans, flora, and fauna. The pathway is the inhalation of particles in the air. Extended inhalation of air contaminated by carbon dioxide particles may cause stunted growth. Further, the receptors are susceptible to lung cancer and respiratory infections.
The second exercise was plastic waste monitoring. The site we visited was a water canal. We investigated the effect of plastic pollution on trees and vegetation along the channel and hyacinths floating in the water. We found that most plastics were food wrappers and various types of polythene. From this exercise, I learned how to collect data for analysis. Due to the rain that fell when we began the activity, we collected incorrect data. As such, the results needed to be fixed. From this exercise, I learned the importance of collecting the correct data to obtain the correct results from the analysis. Proper data collection makes it meaningful, considering that its interpretation will present accurate results. Effective data gathering will facilitate prioritizing scarce resources to the most critical areas. Accurate data collection helps assess the overall state of affairs. The researcher can institute a factual basis for creating correct decisions. The strategy helps maintain research integrity and convince decision-makers to allocate resources accordingly.
Abubakar I.R.2022. Environmental sustainability impacts of solid waste management practices in the Global South. Int J Environ Res Public Health. 19(19). doi: 10.3390/ijerph191912717.
Client Earth. 2021. What are the environmental impacts of waste incineration? [Online] (updated 9 March 2021) Available at: https://www.clientearth.org/latest/latest-updates/stories/the-environmental-impacts-of-waste-incineration/
Joseph W. L., 1962. Air Pollution Control in Municipal Incineration, Journal of the Air Pollution Control Association, 12(9), pp. 414-430, DOI: 10.1080/00022470.1962.10468108
Kabera, T., & Nishimwe, H., 2019. Systems Analysis of Municipal Solid Waste Management and Recycling System in East Africa: Benchmarking Performance in Kigali City, Rwanda; EDP Sciences: Les Ulis, France.
National Research Council (US) Committee on Health Effects of Waste Incineration, 2000. Waste Incineration & Public Health. Washington (DC): National Academies Press (US); 2000. Environmental Transport and Exposure Pathways of Substances Emitted from Incineration Facilities. Available from: https://www.ncbi.nlm.nih.gov/books/NBK233615/
Rajashekar, A., Bowers, A., & Gatoni, A., 2019. Assessing waste management services in Kigali. [Online] (updated July 2019) Available at: https://www.theigc.org/sites/default/files/2019/11/Rajashekar-et-al-2019-paper.pdf
Stones, B., 2016. What is the source, pathway, receptor model? [Online] (updated 11 May 2016 Available at: <https://www.em-solutions.co.uk/insights/what-is-the-source-pathway-receptor-model/>
Vasarhelyi, K., 2021. The hidden damage of landfills. [Online] (updated 15 April 2021) Available at: <https://www.colorado.edu/ecenter/2021/04/15/hidden-damage-landfills#:~:text=Environmental%20Impact%20of%20Landfills&text=Along%20with%20methane%2C%20landfills%20also,create%20smog%20if%20left%20uncontrolled>
Habybabady R.H,et al. 2018. Effects of Dust Exposure on the Respiratory Health Symptoms and Pulmonary Functions of Street Sweepers. Malays J Med Sci. 25(6):76-84. doi: 10.21315/mjms2018.25.6.8.