Abstract

Since the Second World War, plastic has been established as one of the essential materials in many areas of everyday life, gaining strength in sectors such as automotive industry, clothing and decoration. From the 1960s to the present day, the demand for plastic products has grown continuously.

The main objective of this study is to assess the quantity and composition of plastic litter generated in Buea Municipality. The specific objectives include; to determine the quantity of plastic litter generated from households in Buea Municipality, to determine the composition and characterization of plastics litters generated in Buea Municipality, to determine the households’ plastics waste management practices in the Buea Municipality and to determine the potential for recycling of plastic litters generated in Buea Municipality.

The study employed a descriptive survey design to sampled 3 dumpsites from Checkpoint, Chief Street and Mayor Street. Questionnaire was also used an instrument to sampled 40 households on their plastics waste management practices using a convenient and purposive sampling techniques. Based on the study findings, it was revealed that the daily plastics waste generation rate was 47.25kg/day.

Plastics waste identified were characterized in to HDPE, LDPE, PET, PP, PS, PVC and Others. The most dominant form of plastics waste generated a day were PVC (17.4%), follow by LDPE (17.1%), and HDPE (16.8%). The study also revealed that more than 50% of the plastics waste generated had a local recycling market potential.

Households practice very little or no sorting of plastics waste from general waste and also dispose plastics waste either by burning, burying or dumping in an open space. It was suggested that, awareness program on solid waste should be organized on the regular basis to educate both the residents on how to properly manage waste.

CHAPTER ONE

INTRODUCTION

1.1 Background to the study

Plastic has been established as one of the essential materials in many areas of everyday life since the Second World War and is gaining strength in sectors such as the automotive industry, clothing and decoration (Calero et al., 2018).

The demand for plastic products has risen steadily from the 1960s to the present day. In the last fifty years, annual plastics production has increased twenty-fold (Calero et al., 2018). Over the past century, plastic production has grown dramatically from just 1.3 million tons in 1950 to > 322 million tons in 2015 (PE, 2016).

Also noted is a global rise in plastics use at a rate of 4 per cent per year (Miandad et al., 2016). The associated cost of managing plastic solid waste (PSW) drives several countries and communities alike to discard it in open landfill sites. This leads to plastic commodities and articles being accumulated as a major component in the flux of solid waste.

Commercial production of plastics that started around the 1950s has enjoyed exceptional growth, to reach the present global annual production of 330 million metric tonnes (Mt) for 2016 (Plastics Europe, 2017). Including the resin used in spinning textile fibres (Lenzing Group, 2016), this figure is closer to 393 Mt, a value that interestingly matches the global human biomass. At the present rate of growth, plastics production is estimated to double within the next 20 years. This impressive success of plastics is unparalleled by any competing materials used in packaging or construction, the two major applications areas of plastics.

Plastics production is energy-intensive with resins having an embodied energy of 62–108 MJ kg−1 (inclusive of feedstock energy) much higher than for paper, wood, glass or metals (except for Aluminium) (Hammond and Jones, 2008). About 4% of fossil-fuel extracted annually is presently used as raw materials for plastics (British Plastics Federation, 2008) and it is the natural gas liquid fraction or low-value gaseous fraction from petroleum refining that is mostly used to make plastics. The demand for fossil fuel, energy, as well as the associated carbon emissions by the industry, will increase as the future consumer demand for plastics increases.

By the year 2050 plastics manufacturing and processing may account for as much as 20% of the petroleum consumed globally and 15% of the annual carbon emissions budget (World Economic Forum, 2016). There is considerable interest in switching to biomass feedstock to make bioplastics that include the most-used synthetic plastic, polyethene.

Plastic solid waste is bulkier than other organic refuse, thus occupies larger space in landfills (Antelava et al., 2019). Various advances occurred within the past three decades in SW recycling and valorisation. Regardless, ~9.5% of the total plastic produced between 1950 and 2015 has been recycled, while 12.5% has been incinerated and 78% is still discarded in landfills (Geyer et al., 2017).

From computer shells to water bottles, plastics are everywhere in our everyday life. Plastics are not only important to our life but also crucial to the economy. According to the statistics by the American Chemistry Council, the production of major plastic resins was 72.9 billion pounds. Although it decreased by 12.3% compared to in 2007, it is still a very large amount (American Chemistry Council, 2009). Also, the size of the workforce involved in the plastic industry is gigantic, and change in the plastic industry will impact the workers greatly. In the case of the shutdown of a plastic plant in Mt. Olive, 160 people lost their job (Triangle Business Journal, 2008).

Plastic solid waste can be categorized depending on its source or point of origin, i.e. municipal, industrial, medical, etc. Nevertheless, the majority of plastic solid waste is generated from households and commercial sources, which are called municipal plastic waste (MPW) in combination (Ana et al., 2018). This type of solid waste mainly consists of the following plastic resin types: polyethene (PE), polypropylene (PP), polystyrene (PS), polyethene terephthalate (PET) and polyvinyl alcohol (PVC) (Miandad et al., 2017). Municipal solid waste is typically thermoplastics, which are thermally recyclable due to their non-resistance to heat.

Plastic solid waste can be recycled and processed to generate raw materials according to ISO 15270 (2008), and the production of high-calorie compounds can be used as fuels for generating energy. Municipal plastic waste is treated by ascending order of preference from reprocessing and extrusion to utility recovery and energy recovery.

For example, mechanical recycling results in plastic palletization and subsequently raw plastic materials. On the other hand, chemical recycling processes lead to polymer cracking, to monomers allowing the production of polymers and fuels.

Plastic solid waste management, in general, should remove plastic solid waste contamination from the atmosphere and avoid landfilling pollution problems, such as leaching contaminants that may contaminate groundwater aquifers (Al-Salem et al., 2015).

Incinerating SW has become a popular choice of treatment as a waste-to-energy management technology. Nevertheless, incineration of plastic solid waste is reported to cause air and groundwater pollution problems related to the plastic-type and content in the waste, as well as the process conditions, due to the emissions of GHG, SOx, particles, volatile organic compounds (VOCs) and polycyclic aromatic hydrocarbons (PAHs) (Al-Salem et al., 2009).

The world plastic demand is dominated by the thermoplastic polypropylene, polyethene and polyvinyl chloride (Lithner, 2011). Plastic packaging is easy to carry and use, but plastic is a strong pollution factor since today we are surrounded by plastic objects (Jayaraman, 2011; Knight, 2012). Moreover, a nonrenewable natural resource – oil – is needed for plastic production (almost 4% of world oil consumption is used as raw materials for plastic production), while the finished material is not biodegradable (Lithner, 2011).

One of the major environmental problems is the large amount of plastic waste generated. Both, the production of this material and the incorrect waste management cause several environmental problems. One of those problems is the amount of oil needed to manufacture virgin polymers (up to 6% of world oil production).

Other problems are greenhouse gas emissions during manufacture (more than 1% of the world total), low recycling rates of waste and dumping of this waste at sea (World Economic Forum et al., 2016). It is estimated that 80% of the waste present in seas are plastics which come from land (Rojo-Nieto and Montoto, 2017). The problem is that it takes between 100 and 1000 years to degrade plastics, so they suppose a real threat for sea flora and fauna.

Oftentimes, high temperatures cause plastics to leach chemicals. Harmful chemicals are leaching from plastic articles like plastic bottles and plastic containers. A harmful chemical bisphenol A, commonly known as BPA, was found to have leached out of plastic bottles made from Polycarbonate. This is a common component used in plastic bottles and also linings of metal cans. Plastic bottles made for babies contain this chemical that makes the situation even riskier. Frequent wear and tear of bottles like running it in dishwater can be leading to leaching of this chemical. In fact, in a study, new and old bottles filled with room temperature water released the same amount of BPA.  These bottles released BPA up to 55 times more rapidly when exposed to boiling water (Szabo, 2008).

Health hazards of plastics result not only from the manufacturing process and consumption but also from their destruction by incineration. Incineration pollutes air, water, and land exposing workers to toxic chemicals including carcinogens. Their recycling is a challenge in itself, and the fact that used plastics tossed into land never degrade adds to the problem.

Over the years, they are broken down into smaller pieces that are not biodegraded by bacteria in the soil. Their accumulation over the years leads to an increase in toxicity of the soil, which has many adverse effects on plant and animal life that are dependent on soil.

1.2 Statement of the Problem

Plastic waste disposal is one of the major world environmental; problem faced by mankind. Disposal of plastics waste into landfill is considered unsustainable from the environmental point of view. Moreover, landfilled sites and their capacity are decreasing rapidly. Improper disposal of plastics waste led to long term soil and groundwater pollution.

Chemicals used in manufacturing plastics are highly toxic, mainly carcinogens. They are known to have effects on the nervous system, blood, kidneys etc. There are many additives added to plastics at the time of their production like plasticizers, which are known to be harmful. Oftentimes, high temperatures cause plastics to leach chemicals. Harmful chemicals are leaching from plastic articles like plastic bottles and plastic containers.

Several studies have been conducted in Cameroon regarding solid waste management (Mbeng et al, 2012; Managa et al., 2007, Din-Louis, 2015; Tambe et al., 2016). However, these researchers had a great focus on general solid waste management.

To the best of the researcher knowledge, little or no literature exists in Cameroon that covers plastic litter generation, quantification, composition and its recycling potentials. Thus this study aims to determine household’s plastic waste quantification and composition and recycling potentials among residents in Buea Municipality.

1.3 Research Questions

1. What quantity of plastic litters is generated from households in Buea Municipality?
2. What is the composition and characterisation of plastics litters generated in Buea Municipality?
3. How do households manage plastics waste generated within the Buea Municipality?
4. What is the opportunity for plastic waste recycling in Buea Municipality?