Advertisement

Waste Disposal & Sustainable Energy

, Volume 1, Issue 2, pp 117–126 | Cite as

Challenges and prospects of plastic waste management in Nigeria

  • R. U. DuruEmail author
  • E. E. Ikpeama
  • J. A. Ibekwe
Review

Abstract

The combined properties of low cost, lightweight, and resistance to chemicals and corrosion has increased the use of plastic materials for packaging and storage purposes in preference to other materials. Consequently, there is a continued increase in their proportion in domestic solid wastes worldwide as well as the concern of their impacts on the environment. Most developed and developing countries have put in place and continue to improve their plastic waste disposal, collection, and recycling methods to reduce these impacts. In Nigeria with a population of about 186 million, there are little or no available data on the use of plastic materials in relation to city populations, their disposal, collection, and recycling methods. There are a few numbers of plastic waste recycling companies in a fewer number of cities and disposal practices for the greater percentage of the plastic wastes that are not captured for recycling possess immediate and future danger for the environment. This work reviews the consumption of plastics, its waste generation, collection, and treatment in Nigeria and a few selected countries. The problems associated with inadequate management of the wastes were emphasized and recommendations were proffered to not only highlight research and investment opportunities that are inherent in plastic waste management in Nigeria, but also provide a background for the formulation of sustainable regulatory policies by the government to address the problems.

Keywords

Plastic waste Disposal Recycling Environment Investment Waste management 

Introduction

Plastics are synthetic organic materials that can easily be molded into the desired shape when soft and then set into rigid forms that are slightly elastic. They are used in various applications such as packaging, electronics, medicals, aerospace, transportation, building, and construction [1]. Their preference in these areas to other types of material is encouraged by their low cost, lightweight, and resistant to chemicals, and this has consequently led to the recent increase in the proportion of plastic wastes in both domestic and industrial solid wastes. Plastic wastes also increase further as the human population increases. The Nigerian population growth rate from year 2000 to 2017 is at the average of 2.37 [2], and this can be related directly to the rate of increase in Municipal Solid Waste (MSW) generally and, by extension, plastic wastes.

In the year 2007, the world plastic production was estimated to be 260 million metric tons per annum with thermoplastic resins alone contributing about 67% [3, 4]. This estimate increased to 348 million metric tons in 2017 [5]. The authors further estimated that about 50% of plastic produced is employed for single-use disposable applications such as packaging and other dispensable consumer items. Most of these materials are not biodegradable and are not part of the food chain. Thus, they end up in landfills and our water bodies where there is an absence or inefficient management of wastes, a situation that is more prevalent in developing countries.

There are inadequate or lack of statistical data on the production and importation of plastic materials and their resulting wastes in Nigeria. Majority of the consumers lack the awareness of immediate and remote consequences of their generated and mismanaged plastic wastes.

The level of the well-being of a people may be linked to the extent to which they treat their plastic wastes. Rukina and Filatov [6] put this in another perspective by stating that the general state of the culture of a people can be mirrored in their ability to properly dispose and recycle their plastic wastes.

The theme for the 2018 world environmental day hosted by India was ‘Beat Plastic Pollution’ [7]. Several developed and developing countries had, before now keyed into this call with policies, strict regulations and technological advancement in the treatment plastic wastes. An insight into this global trend is provided here for the nation to urgently and critically re-assess her position and be guided in formulating policies and enforceable regulations that would help in protecting the environment.

Types of plastics and their applications

Thermoplastics

These types can be melted back into their liquid state on application of heat and remolded into the same or different shape for the same or different use. Thermoplastics contribute roughly 80% to the total plastic consumption [8]. Some examples of thermoplastics, their properties, and application are shown in Table 1.
Table 1

Types, properties, and applications of thermoplastics

Type

Properties

Application

Polyethylene (PE)

Translucent, tough and semi-rigid, chemical resistance, waterproof and low cost

Packaging (plastic bottles, bags, wraps, and films), construction

Polypropylene (PP)

Translucent, tough and semi-rigid, chemical resistance, fatigue resistance, heat resistance and living hinge property

Packaging and containers, toys, medicine, automotive parts, tubing, furniture, Laboratory equipment

Polyethylene terephthalate (PET)

Wear resistance, Low coefficient of friction

Bottles, textiles, electricals, cosmetic containers

Polyvinyl chloride (PVC)

Fire retardant, durability, chemical resistance

Pipes, insulation, footwears, automotive parts

Polystyrene (PS)

Lightweight, rigid

Insulation, packaging

Polymethyl methacrylate (PMMA)

High UV light and chemical resistant, transparency, durability

Automotive lamp covers an alternative to glass in certain applications

Thermosets

Thermoset types of plastic cannot return to their original form once cured (cooled and hardened). They are produced by crosslinking of similar or different polymer chains through chemical bonding. They are harder, stronger, and more durable than the thermoplastic but generally non-recyclable. It has been found in recent studies, however, that certain thermosets can be recycled via bond exchange reactions [9] or by further reactions of the active sites in the already cured thermoset [10]. Examples of thermosets include epoxy resin, polyurethanes, and phenolic and polyester resins. They are used for auto parts, electrical fittings, aircraft parts, tires, etc. Thermosets contribute 20% of the world total plastic consumption.

Plastic consumption/waste generation

The packaging sector is one of the major consumers of plastics as the use of packaged materials has become part of our daily lives. It has been approximated that 30% of plastics produced worldwide are used for packaging application [11, 12]. In their own report, Hopewell et al. [3] posited that approximately 50% of the plastics used are single-use disposables for packaging, agricultural films, etc. The statistics of plastic consumption and its concomitant waste generation will generally vary from country to country and from city to city. The global Municipal Solid Waste in 1997 was put at 0.49 billion tons with an estimated annual growth of 3.2–4.5% and 2–3% in developed and developing countries, respectively [13]. By 2016, the global MSW was reported to have hit 1.47 billion metric tons [14]. Table 2 shows the population, quantity of solid waste, and percentage of plastic waste generation in some developed and developing countries or cities.
Table 2

Population and plastic waste generation in some developed and developing countries or cities

Country/city

Population (million)

Year

MSW (million tons/year)

Average MSW (g/capita/day)

Ave. plastic waste (%)

Accra (Ghana)

4.0

2010

0.43

567

3.3a,b,c

Nairobi (Kenya)

2.3

1996

0.37

NA

12.6dd

Rashat (Iran)

0.5

2007

0.15

800

3.5e

Delhi (India)

8.4

2000

1.42

475

1.5f,g

Singapore

3.9

1999

1.36

960

5.8h

Malaysia

26.6

2007

25.70

800

18.9i,j

USA

269.4

1996

209.70

1950

12.3k,l

Libya

5.9

2014

1.61

1120

8.0m

Rajshashi (Bangladesh)

0.75

2014

0.14

400

4.7n

China

1330.0

2008

150.0

980

o,p,q

a–q[15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31]

In Nigeria, there are few or no records of plastic waste generation rates in the cities. The composition of solid wastes generally depends on the location (residential, institutional, industrial, and markets) as well as the season. For example, while it is expected that waste collection points near markets will contain more fruits and vegetables, that of high-income residential areas will contain more of used plastic bags and bottles. Table 3 shows the average solid-waste generation against the population of some cities in Nigeria [32]. Tobore [33] further stated that a study carried out by the Bayero University Consultancy Unit in 2012 estimated the waste composition to be 19% of Polythene, 12.7% of paper, 10% of metals, 8.7% of glass, 11.3% of plastics, and 38.3% of biodegradable and other miscellaneous waste. The percentage of plastic in that report did not capture the litters that hardly make it to the waste bins and collection points.
Table 3

Solid-waste generation in some urban cities in Nigeria [32]

City

Population

Tonnage/month

Density (kg/m3)

kg/Capita/Day

Lagos

8,029,200

255,556

294

0.63

Kano

3,248,700

156,676

290

0.56

Ibadan

307,840

135,391

330

0.51

Kaduna

1,458,900

114,433

320

0.58

Port Harcourt

1,053,900

117,825

300

0.60

Makurdi

249,000

24,242

340

0.48

Onitsha

509,500

84,137

310

0.53

Nsukka

100,700

12,000

370

0.44

Abuja

159,900

14,785

280

0.66

A preponderant percentage of plastic consumption in Nigeria is for short life products and this, if investigated, will most likely give rise to a low weighted average service life of all plastic products and, consequently, a high plastic component of waste streams. In Germany, a developed country, the weighted average service life of all plastic products is estimated to be 14 years while that of India is 8 years [34, 35].

Among the non-biodegradable components of solid wastes in Nigeria, plastic materials are perhaps to most dominant (see Fig. 1a). In an integrated waste management facility study done for six districts in Abuja, the capital city, the average percentage of all plastics in the waste streams was found to be 19.4%, second to food remnant, probably due to higher earning capacity and lifestyle of the households studied (Table 4).The reason for the high content of plastics in our wastes is essentially due to the fact that waste scavengers mostly prefer scraps of metals usually iron, aluminum, and copper materials, an indication that the demand and, hence, the recycling of these metals are by far higher than that of plastics. Another reason for the prevalence of the plastic wastes in the dumps is the common use of polyethylene shopping bags and the sachet water production and sales that evolved since the late 1990s. In a typical market for food items, almost every item is handed to the buyer in a mini polyethylene bag that is not re-used. In recent times also, there has been an increase in the packaging of common household items such as noodles, detergents, beverages, and germicides in sachets of plastic materials that are not recyclable. Children and adults alike consume certain snacks and beverages while on the move and most of them are packaged with plastic materials which the consumers deposit along the streets, major roads, and highways. As a result, litters of plastics materials ranging from sweet and biscuit wraps to PET bottles and sachet water packaging are common sights in the streets of most cities, public places, and some institutions. This is depicted in Fig. 1b, c. They eventually end up in nearby farmlands and drainages. It is worthy to note that the majority of the populace including the educated harbors this habit, ignorant of the adverse effects of plastic wastes in the environment. In some countries, there are laws or corrective work orders that do not permit people to litter without attracting fines and corrective punishment [22].
Fig. 1

a A roadside waste collection point showing more of plastic materials. b A typical untarred urban residential street with litters of plastic materials. c A drainage system in a city capital filled with all forms of plastic wastes. d An overfilled waste dumpsite with scavengers searching for some recyclable materials

Table 4

Average composition (%) of household wastes in Apo, Asokoro, Garki, Gwarimpa, Maitama, and Wuse districts of Abuja

Type of waste

Average composition (%)

Paper

11.41

Metal

5.20

Glass

4.65

All plastics

19.34

Food remnants

54.77

Textile

2.53

Others

2.10

Adapted from [36, 37]

Recovery of plastic waste

With a population of about 186 million people, the country generates an average of 0.58 kg solid waste per person per day [38]. This translates to over 100,000 tons of solid waste per day, making it one of the largest in Africa. Abila and Kantola [39] estimated the country’s MSW to be 25 million tons per year. At a conservative value of 10% plastic content, this will further suggest that over 10,000 tons of plastic waste are generated daily. Sadly, with the improper disposal methods and inherent management challenges, more than half of these wastes are either buried in the farmlands or are in the drainages and the waterways (Fig. 1c).

In general, as in the case of most developing countries, solid-waste management in Nigeria grapples with many challenges ranging from lack of technical capacity to very poor financing and mismanagement [19, 39, 40, 41, 42]. The federal government of Nigeria, through an act in 2004, established the Federal Environmental Protection Agency (FEPA), to design, regulate, and enforce rules for waste management and other environmental issues nationwide. Most states also established their agencies to compliment that of FEPA. Examples include Lagos State Environmental Protection Agency (LASEPA), Enugu State Waste Management Agency (ESWAMA), Rivers State Waste Management Agency (RIWAMA), and Kano State Environmental Protection Agency (KASEPA). For a better-articulated responsibility, the FEPA was replaced with the National Environmental Standards and Regulations Enforcement Agency (NESREA) through another act in 2007. It was designed to focus her regulatory work on individuals and organizations (except oil and gas) whose activities pose a threat to the environment [43]. In all, there is still a huge gap in the management and the output of these agencies as the appointment of the managers and the operators are based more on political affiliations than on qualifications or experience. NESREA has up to 30 regulatory statements, but seemed to be lacking in the compliance monitoring and enforcement aspects. At their best, most states could only evacuate wastes from the residential areas regularly to designated dumpsites. Ogwueleka [32] reported waste collection efficiency to be between 5% in semi-urban and 50% in urban areas. There are cases of seeming dispersal of the wastes from the collection points to dump sites by the supposed disposal (open and uncovered) trucks due to overloading. To this end, litters of the lightweight plastic materials trail the trucks en-route to the dumpsites.

In nearly all the states in Nigeria, waste collection services are provided for the cities only. The rural dwellers deal with their wastes generally as it suits them. Some of the plastic wastes are either burnt or thrown into nearby farmlands within and around their residences. However, it is worthy to note that complete recovery of plastic waste is not easily achievable even in some developed countries with increased improvement in plastic waste collection and recycling methods. Hopewell et al. [3] recorded that Western Europe achieved only 39% of the total recovery rate out of the 21.1 million tons of plastic waste generated in 2003. They added that any expected gains in the recovery trends will be counterbalanced by the concomitant increasing trend in the generation of the waste.

Over the years, the cumulative effects of unrecovered plastic wastes in Nigeria lead to low crop yields in the farmlands. It has been identified that flooding of the major roads and some residential areas in the cities are caused by clogging of the drainages and sewage systems by these plastic wastes (Fig. 1c). With time, the ones that end up in the oceans and water bodies degrade to microplastics and water-soluble components with their attendant consequences including exposure of the aquatic environment to toxins which may eventually find their way into our food chain [44, 45]. This implies, therefore, that coastal countries with an inadequate plastic waste management system may have a fair share of the contributions to the worldwide marine plastic pollution. Jambeck et al. [46] had estimated that over 4% of 275 metric tons of plastic wastes generated by 192 coastal countries in 2010 entered the ocean. In a prediction with global river plastic inputs model that used geospatial data of population density, rates of mismanaged plastic waste production, and other parameters, three Nigerian rivers were listed among world top 20 polluting rivers [47]. Investigation of the cause of a recent boat mishap in a riverine area of Port Harcourt metropolis revealed that the engine was suddenly knocked off by shreds of plastic wastes that tangled with the propeller blades.

Whether in the ocean, farmland, or buried underground, it goes that plastic wastes are like seeds sown by man, who will eventually reap the ugly ‘fruits’ that it bears whenever and wherever it ripens.

Management of plastic materials and wastes

Degradation

Plastics may be degraded by one or more of the following: heat (thermodegradation), Light (photodegradation), micro-organisms (biodegradation), and chemicals (chemodegradation) [12]. Biodegradable plastics are plastics that can be completely degraded by the action of naturally occurring micro-organisms depending on the environmental condition [48].

Going by the method of our management (or rather, mismanagement) of plastic materials in the country, we ought to rely heavily on micro-organisms for the degradation of our plastic wastes. However, it may take several years for nature to completely degrade a piece of plastic. Shimao [49] stated that a number of polyesters have been found to be biodegradable due to the easily hydrolysable ester linkages and polyhydroxyalkanoates (a bacterial polyester) which can now be incorporated in the production of biodegradable plastics. Plastic shopping bags which are the most dominant in our waste streams can be produced with polylactic acid. Polylactic acid is a polymer that biodegrades easily under composting conditions without toxic residue.

A strain of Rhodococcus rubber has been found to significantly degrade Polyethylene films [50, 51]. There are few available reports on the biodegradability of polyvinylchloride and polystyrene [12]. However, several works have established that Polyethylene which is more prevalent in our waste dumps can be modified at the production stages to enhance its biodegradability. This is achieved by modifying one or more of its mechanical properties that are responsible for its resistance towards biodegradabilities such as crystalline level and molecular weight [52]. In this view, Evangelista [53] and Bikiaris et al. [54] increased the hydrophilicity of polyethylene by blending with starch. Johnson et al. [55] also demonstrated that compounding polyethylene with starch and transition metal additives promotes its degradation in the natural environment. To avoid or reduce the impact on food grade starch, efforts of research and innovative technologies have been shifted to the use of non-edible biomass waste which contains a large number of cellulosic by-products [48, 56, 57]. Plastics’ biodegradability has been exploited in their waste management strategy via anaerobic digestion by converting the bio-waste into methane which is resourceful for energy production [58].

Reuse, reduce, recycle, recover, and reject

A synoptic management method of plastic materials and their wastes will be best considered under the 5 Rs of Reduce, Reuse, Recycle, Recover, and Refuse (Fig. 2). Reusable as well as recyclable plastics should always be preferred. Reduction strategy can be applied using or accepting plastic packages only when it is necessary as well as using only one re-useable bag for typical market purchases instead of packaging every item with a mini-plastic bag. Rejection should be applied when one is not sure of getting the resulting plastic waste to a collection point for recycling or when the plastic packaging is non-recyclable.
Fig. 2

A synoptic management method of plastic materials

Plastic wastes can be significantly reduced if the populace imbibes the culture of re-using plastic materials. Unfortunately, most of the packaging materials are designed for single use, especially the polyethylene bags that come in miniature of sizes. Some polypropylene bags are designed for reuse; however, most consumers do not reuse them, either due to impromptu shopping that requires a fresh bag or out of habit. With the accumulation in their homes, they all soon end up in the waste bins, leading to a high proportion of plastic wastes (Fig. 1b). In other to discourage the use of plastic bags and associated materials or encourage their reuse, some developed (Ireland, Australia, and San Francisco) and developing (China, Rwanda, Botswana, Bangladesh, Kenya, South Africa) countries/regions have banned the use of plastic bags or imposed some form of tax in their use [59, 60, 61, 62, 63, 64, 65]. The law in Kenya which is today regarded as the world’s toughest plastic ban attracts a fine that may be up to $40,000 or a 4-year jail term for production, sale, or use of polyethylene plastic bags.

Except in facilities owned by some corporate and multinational companies, sorting of wastes into their various types is non-existent at the households as well as at the collection points. Existing recycling plants may be discouraged by the cost of sorting and cleaning heterogeneous plastic wastes taken directly from the mixed waste dumps. Some recycling outfits in Lagos operate an incentive-based scheme in which recyclable materials are collected from post consumers and rewarded.

Landfills

Modern landfills are professionally designed to hold a large volume of wastes with proper underlays and leachate collection systems that prevents contamination of the adjourning environment, especially the underground water. The dumpsites around the country are far from being a modern landfill. They are usually borrow pits that had previously served as laterite excavation sites for road construction (Fig. 1d). For years, the use of dumpsites has been the traditional approach of solid-waste management in Nigeria. With time, seepages from these unprotected sites get to underground water and resulting to its contamination. Substantial quantities of plastics end up in the dumpsites due to lack of segregation, thus, resulting in both waste management and environmental issues [1, 26]. In some dry seasons, heaps of these dumpsites will be set on fire for the purpose of reducing the volume to accommodate more wastes. As a consequence, toxic gases such as dioxins and other polychlorinated biphenyls (PCBs) are released into the environment.

Recycling

Considering the high demand for plastic materials and the corresponding wastes generated, recycling is presently the most viable method that could be used for its minimization. Recycling is the process of converting materials that could have been considered as waste into new products. This waste management strategy helps to reduce the amount of waste sent to landfills as well as reduce greenhouse gas emissions that contribute to climate change, thereby helping to sustain the environment. This strategy also helps to reduce the requirement for plastic production, saves energy, and conserves fossil fuels, since plastic production is dependent on non-renewable sources [3, 66, 67]. According to Stanford University Peninsula Sanitary Service Incorporation, recycling 1 ton of plastics is equal to saving 5774 kilowatts/hour of energy, 16.3 barrels of oil, and 30 cubic yards of landfill space.

Plastic recycling technologies can be grouped into four categories:
  1. 1.

    Primary recycling—involves waste processing into a product of similar characteristics.

     
  2. 2.

    Secondary recycling—involves the processing of waste into products of different characteristics.

     
  3. 3.

    Tertiary recycling—involves the production of basic chemicals and fuel from segregated municipal waste.

     
  4. 4.

    Quaternary recycling—involves energy extraction by partial or complete oxidation of the material [1, 66].

     

Plastic recycling can be difficult considering the components used in its production process, such as different polymers, pigments, adhesives, paper, etc., and also if not sorted and separated from the sources [3]. While most cities in Nigeria do not have plastic recycling plants, existing ones in cities like Aba, Abuja, Kano, Lagos, and Onitsha have capacities that may take less than 30% of all recyclable plastics if they were all recovered and they are mostly engaged in the secondary methods of recycling. In comparison, a country like India has a record of recycling 50–80% of all plastic used, while Germany, adjudged to have the largest market of recycled plastic in Europe, has a record of 100% all plastic waste recycling [11, 21]. To promote mechanical recycling of PET bottles alone in the municipalities of the capital city, Japan established a council for PET bottle recycling in 1993 [66].

However, when plastic wastes are heterogeneous or consist of mixed resins, they are unsuitable for reclamation. In this case, thermal cracking into hydrocarbons which is termed chemical recycling may provide a suitable means of recovery [68]. This falls into the category of tertiary recycling. It involves their conversion into the smallest molecules (liquids and gases) that can be employed as suitable feedstocks for the production of new petrochemicals and plastics [69]. Pyrolysis is the major method of chemical recycling and has attracted several research efforts [67, 70, 71, 72, 73].

Quaternary recycling methods are employed where other recovery routes are not feasible. It involves subjecting the PSW to integrated incineration to recover the inherent energy in the form of heat, steam, or electricity. Plastic materials are known to have calorific values that are comparable to that of major crude oil products [66, 74]. This method commonly referred to Waste To Energy (WTE) method can be applied directly to MSW to produce steam and/or electricity. Themelis [75] estimated that 300 million tons of MSW are combusted annually in over 600 WTE facilities worldwide. Though WTE requires high capital investment compared to other MSW management methods, it has the advantage of requiring little or no pre-treatment of waste and is more environmentally friendly [30]. Nigeria with the largest economy in sub-saharan Africa and challenges in power generation is yet to advance to this level of waste treatment. Out of her current capacity to generate 12,522 megawatts (MW) of electric power, only about 4000 MW is generated daily which is grossly insufficient for the over 186 million population [76]. In another advanced recycling method, plastic wastes can be blended with bitumen for road tarring and the blends have shown to have better resistance to rainwater, cracking, and deformation of bituminous layers as well as decreased consumption of bitumen [77, 78, 79, 80].

Recommendations and conclusions

Nigeria and most other countries are already at the receiving end of the effects of plastic waste mismanagement for several years now and this is, unfortunately, still on the increase. Urgent and robust policy framework in the production, use, and recycling of plastics and its wastes (cradle-to-grave) need to put in place to save the environment. The following set of recommendations that may help in formulating sustainable policies in plastic management is advanced.
  1. 1.

    A strong public education program on the need for proper disposal of plastic materials should be instituted by environmental agencies at all levels of the government, starting from the primary schools.

     
  2. 2.

    Households should be encouraged to sort their wastes at source before disposal to central collection centers. This can be done by rewarding or paying for recyclable materials such as metals and plastics, while minimal fees should be imposed on unsorted wastes.

     
  3. 3.

    Plastic waste collection centers should be set up at several points in the urban areas and at least one center in the rural Local Government Areas which can also serve as pre-treatment centers.

     
  4. 4.

    Private partner participation should be encouraged with adequate incentives in both the collection and recycling of plastic wastes.

     
  5. 5.

    Records of plastic consumption (companies’ local production and importation data) as well as plastic wastes and the capacities of recycling companies should compulsorily be domiciled with the Federal Ministry of Environment and updated regularly.

     
  6. 6.

    There should be legislation against the use of non-recyclable plastics for packaging, while more research efforts should be directed towards the production and application of biodegradable plastics in the country.

     
  7. 7.

    Considering the grave energy requirements of the country, investing in WTE will increase power generation, provide employment at the time, and drastically reduce the volume of plastic wastes that may require alternative methods of treatment.

     
  8. 8.

    To help some developing countries that may not have adequate mechanism to sensitize its citizens on the proper use of plastics and management of the resulting wastes, bodies like United Nations through the W.H.O. may need to have some set of rules and policies on the use of plastics and management of its wastes for all its member nations to strictly adhere to.

     

This generation and subsequent generations should take the environment as a loan from future generations which must be paid back with interest by bequeathing it better than we found it. We can only be close to achieving this by making conscious efforts in preventing these plastic wastes that may last hundreds of years, from getting to the environment. Policy statements on the use of plastic and management of its wastes will also help the country towards the efforts of achieving some of the Sustainable Development Goals (SDGs), especially 13–15.

Notes

References

  1. 1.
    Siddiqui J, Pandey G. A review of plastic waste management strategies. Int Res J Environ Sci. 2013;13(2):12.Google Scholar
  2. 2.
  3. 3.
    Hopewell J, Dvorak R, Kosior E. Plastics recycling: challenges and opportunities. Philos Trans R Soc B Biol Sci. 2009.  https://doi.org/10.1098/rstb.2008.0311.Google Scholar
  4. 4.
    Geyer R, Jambeck JR, Law KL. Production, use, and fate of all plastics ever made. Sci Adv. 2017.  https://doi.org/10.1126/sciadv.1700782.Google Scholar
  5. 5.
  6. 6.
    Rukina IM, Filatov VV. The role of fundamental values in social development. Microeconomics. 2017;4:107–16.Google Scholar
  7. 7.
  8. 8.
    Garraín D, Martínez P, Vidal R et al. LCA of thermoplastics recycling. In Proceedings of 3rd international conference of life cycle assessment, Zurich, August 2007 Aug (pp. 27–29).Google Scholar
  9. 9.
    Yu K, Taynton P, Zhang W, et al. Reprocessing and recycling of thermosetting polymers based on bond exchange reactions. RSC Adv. 2014;4:10108–17.  https://doi.org/10.1039/C3RA47438K.CrossRefGoogle Scholar
  10. 10.
    García JM, Jones GO, Virwani K, et al. Recyclable, strong thermosets and organogels via paraformaldehyde condensation with diamines. Science. 2014;344(6185):732–5.  https://doi.org/10.1126/science.1251484.CrossRefGoogle Scholar
  11. 11.
    Patel M, von Thienen N, Jochem E, et al. Recycling of plastics in Germany. Resour Conserv Recycl. 2000;29:65–90.  https://doi.org/10.1016/S0921-3449(99)00058-0.CrossRefGoogle Scholar
  12. 12.
    Shah AA, Hasan F, Hameed A, et al. Biological degradation of plastics: a comprehensive review. Biotechnol Adv. 2008;2:246–65.  https://doi.org/10.1016/j.biotechadv.2007.12.005.CrossRefGoogle Scholar
  13. 13.
    Suocheng D, Tong KW, Yuping W. Municipal solid waste management in China: using commercial management to solve a growing problem. Utilit Policy. 2001;10:7–11.  https://doi.org/10.1016/S0957-1787(02)00011-5.CrossRefGoogle Scholar
  14. 14.
    Zaman AU. A comprehensive study of the environmental and economic benefits of resource recovery from global waste management systems. J Cleaner Product. 2016;124:41–50.  https://doi.org/10.1016/j.jclepro.2016.02.086.CrossRefGoogle Scholar
  15. 15.
    Boadi KO, Kuitunen M. Municipal solid waste management in the Accra Metropolitan Area, Ghana. Environmentalist. 2003;23:211–8.CrossRefGoogle Scholar
  16. 16.
    Benneh G. ‘Environmental Consequences of Different Patterns of Urbanisation,’ in population, environment and development. In: Proceedings of the U.N. expert group meeting on population, environment and development 1994 20–24 January, pp. 159–165, The United Nations, New York.Google Scholar
  17. 17.
    Kramer H, Jechimer K, Lengsfeld S, et al. Determination of major planning data for solid waste management in Accra metropolis, Accra metropolitan assembly, waste management department. Ghana: Accra; 1994.Google Scholar
  18. 18.
    Henry RK, Yongsheng Z, Jun D. Municipal solid waste management challenges in developing countries–Kenyan case study. Waste Manag. 2006;26:92–100.  https://doi.org/10.1016/j.wasman.2005.03.007.CrossRefGoogle Scholar
  19. 19.
    Moghadam MA, Mokhtarani N, Mokhtarani B. Municipal solid waste management in Rasht City, Iran. Waste Manag. 2009;29:485–9.  https://doi.org/10.1016/j.wasman.2008.02.029.CrossRefGoogle Scholar
  20. 20.
    Sharholy M, Ahmad K, Mahmood G, et al. Municipal solid waste management in Indian cities—a review. Waste Manag. 2008;28:459–67.  https://doi.org/10.1016/j.wasman.2007.02.008.CrossRefGoogle Scholar
  21. 21.
    Nandy B, Sharma G, Garg S, et al. Recovery of consumer waste in India—a mass flow analysis for paper, plastic and glass and the contribution of households and the informal sector. Resour Conserv Recycl. 2015;101:167–81.  https://doi.org/10.1016/j.resconrec.2015.05.012.CrossRefGoogle Scholar
  22. 22.
    Bai R, Sutanto M. The practice and challenges of solid waste management in Singapore. Waste Manag. 2002;22:557–67.  https://doi.org/10.1016/S0956-053X(02)00014-4.CrossRefGoogle Scholar
  23. 23.
    Kathirvale S, Yunus MN, Sopian K, et al. Energy potential from municipal solid waste in Malaysia. Renew Energy. 2004;29:559–67.  https://doi.org/10.1016/j.renene.2003.09.003.CrossRefGoogle Scholar
  24. 24.
    Manaf LA, Samah MA, Zukki NI. Municipal solid waste management in Malaysia: practices and challenges. Waste Manag. 2000;29:2902–6.  https://doi.org/10.1016/j.wasman.2008.07.015.CrossRefGoogle Scholar
  25. 25.
  26. 26.
    Subramanian PM. Plastics recycling and waste management in the US. Resour Conserv Recycl. 2000;28:253–63.  https://doi.org/10.1016/S0921-3449(99)00049-X.CrossRefGoogle Scholar
  27. 27.
    Hamad TA, Agll AA, Hamad YM, et al. Solid waste as renewable source of energy: current and future possibility in Libya. Case Stud Thermal Eng. 2014;4:144–52.  https://doi.org/10.1016/j.csite.2014.09.004.CrossRefGoogle Scholar
  28. 28.
    Halder PK, Paul N, Hoque ME, et al. Municipal solid waste and its management in Rajshahi City, Bangladesh: a source of energy. Intl J Renew Energy Res (IJRER). 2014;4:168–75.Google Scholar
  29. 29.
    National Bureau of Statistics of China, 2009. China Statistical Yearbook 2009. http://www.stats.gov.cn/tjsj/ndsj/2009/indexeh.htm.
  30. 30.
    Cheng H, Hu Y. Municipal solid waste (MSW) as a renewable source of energy: current and future practices in China. Bioresour Technol. 2010;101:3816–24.  https://doi.org/10.1016/j.wasman.2012.04.016.CrossRefGoogle Scholar
  31. 31.
    Zhang DQ, Tan SK, Gersberg RM. Municipal solid waste management in China: status, problems and challenges. J Environ Manag. 2010;91:1623–33.  https://doi.org/10.1016/j.jenvman.2010.03.012.CrossRefGoogle Scholar
  32. 32.
    Ogwueleka TC. Municipal solid waste characteristics and management in Nigeria. Iran J Environ Health Sci Eng (IJEHSE). 2009;6(3):173–80.Google Scholar
  33. 33.
    Tobore IE. Solid waste management in Nigeria. Lagos: A paper presentation on Waste Management; 2012.Google Scholar
  34. 34.
    Mutha NH, Patel M, Premnath V. Plastics materials flow analysis for India. Resour Conserv Recycl. 2006;47:222–44.  https://doi.org/10.1016/j.resconrec.2005.09.003.CrossRefGoogle Scholar
  35. 35.
    Panda AK, Singh RK, Mishra DK. Thermolysis of waste plastics to liquid fuel: a suitable method for plastic waste management and manufacture of value added products—A world prospective. Renew Sustain Energy Rev. 2010;14:233–48.  https://doi.org/10.1016/j.rser.2009.07.005.CrossRefGoogle Scholar
  36. 36.
    Federal Ministry of Environment Report. LAGA International, 2004.Google Scholar
  37. 37.
    Imam A, Mohammed B, Wilson DC, et al. Solid waste management in Abuja, Nigeria. Waste Manag. 2008;28:468–72.  https://doi.org/10.1016/j.wasman.2007.01.006.CrossRefGoogle Scholar
  38. 38.
    Babayemi JO, Dauda KT. Evaluation of solid waste generation, categories and disposal options in developing countries: a case study of Nigeria. J Appl Sci Environ Manag. 2009;13(3).Google Scholar
  39. 39.
    Abila B, Kantola J. Municipal solid waste management problems in Nigeria: evolving knowledge management solution. In: Proceedings of World Academy of Science, Engineering and Technology 2013 (No. 78, p. 292). World Academy of Science, Engineering and Technology (WASET).Google Scholar
  40. 40.
    Cointreau S. Waste collection systems in developing countries. Available at http://siteresources.worldbank.org/INTURBANDEVELOPMENT/Resources/336387-124907. 5 Mar 2005. 3752263:6354451-1249073991564.
  41. 41.
    Guerrero LA, Maas G, Hogland W. Solid waste management challenges for cities in developing countries. Waste Manag. 2013;33:220–32.  https://doi.org/10.1016/j.wasman.2012.09.008.CrossRefGoogle Scholar
  42. 42.
    Ezechi EH, Nwabuko CG, Enyinnaya OC, et al. Municipal solid waste management in Aba, Nigeria: challenges and prospects. Environ Eng Res. 2017;22:231–6.  https://doi.org/10.4491/eer.2017.100.CrossRefGoogle Scholar
  43. 43.
    Enenwaene MI. The place of National Environmental Standards and Regulations Enforcement Agency (NESREA) on Environmental Management in Nigeria. 12th Faculty of Science Lecture Series, University of Port Harcourt, Nigeria (May 12, 2019).Google Scholar
  44. 44.
    Joyner CC, Frew S. Plastic pollution in the marine environment. Ocean Dev Int Law. 1991;22:33–69.CrossRefGoogle Scholar
  45. 45.
    Lamb JB, Willis BL, Fiorenza EA, et al. Plastic waste associated with disease on coral reefs. Science. 2018;359(6374):460–2.  https://doi.org/10.1126/science.aar3320.CrossRefGoogle Scholar
  46. 46.
    Jambeck JR, Geyer R, Wilcox C, et al. Plastic waste inputs from land into the ocean. Science. 2015;347(6223):768–71.  https://doi.org/10.1126/science.1260352.CrossRefGoogle Scholar
  47. 47.
    Lebreton LC, Van der Zwet J, Damsteeg JW, et al. River plastic emissions to the world’s oceans. Nat Commun. 2017;8:15611.  https://doi.org/10.1038/ncomms15611.CrossRefGoogle Scholar
  48. 48.
    European Bioplastics. http://www.european-bioplastics.org/. Accessed 22 Sept 2017.
  49. 49.
    Shimao M. Biodegradation of plastics. Curr Opin Biotechnol. 2001;12:242–7.  https://doi.org/10.1016/S0958-1669(00)00206-8.CrossRefGoogle Scholar
  50. 50.
    Orr IG, Hadar Y, Sivan A. Colonization, biofilm formation and biodegradation of polyethylene by a strain of Rhodococcus ruber. Appl Microbiol Biotechnol. 2004;65:97–104.  https://doi.org/10.1007/s00253-004-1584-8.Google Scholar
  51. 51.
    Sivan A, Szanto M, Pavlov V. Biofilm development of the polyethylene-degrading bacterium Rhodococcus ruber. Appl Microbiol Biotechnol. 2006;72:346–52.  https://doi.org/10.1007/s00253-005-0259-4.CrossRefGoogle Scholar
  52. 52.
    Albertsson AC, Barenstedt C, Karlsson S. Abiotic degradation products from enhanced environmentally degradable polyethylene. Acta Polym. 1994;45:97–103.CrossRefGoogle Scholar
  53. 53.
    Evangelista RL, Sung W, Jane JL, et al. Effect of compounding and starch modification on properties of starch-filled low-density polyethylene. Ind Eng Chem Res. 1991;30:1841–6.  https://doi.org/10.1021/ie00056a025.CrossRefGoogle Scholar
  54. 54.
    Bikiaris D, Aburto J, Alric I, et al. Mechanical properties and biodegradability of LDPE blends with fatty-acid esters of amylose and starch. J Appl Polym Sci. 1999;71(7):1089–100.  https://doi.org/10.1002/(SICI)1097-4628(19990214)71:7%3c1089:AID-APP7%3e3.0.CO;2-I.CrossRefGoogle Scholar
  55. 55.
    Johnson KE, Pometto AL, Nikolov ZL. Degradation of degradable starch-polyethylene plastics in a compost environment. Appl Environ Microbiol. 1993;59:1155–61.Google Scholar
  56. 56.
    Carlsson M, Lagerkvist A, Morgan-Sagastume F. The effects of substrate pre-treatment on anaerobic digestion systems: a review. Waste Manag. 2012;32:1634–50.  https://doi.org/10.1016/j.wasman.2012.04.016.CrossRefGoogle Scholar
  57. 57.
    Ravindran R, Jaiswal AK. A comprehensive review on pre-treatment strategy for lignocellulosic food industry waste: challenges and opportunities. Bioresour Technol. 2016;199:92–102.  https://doi.org/10.1016/j.biortech.2015.07.106.CrossRefGoogle Scholar
  58. 58.
    Song JH, Murphy RJ, Narayan R, et al. Biodegradable and compostable alternatives to conventional plastics. Philos Trans R Soc Lond B: Biol Sci. 2009;364:2127–39.  https://doi.org/10.1098/rstb.2008.0289.CrossRefGoogle Scholar
  59. 59.
    Convery F, McDonnell S, Ferreira S. The most popular tax in Europe? Lessons from the Irish plastic bags levy. Environ Resour Econ. 2007;38:1.  https://doi.org/10.1007/s10640-006-9059-2.CrossRefGoogle Scholar
  60. 60.
    Xing X. Study on the ban on free plastic bags in China. J Sustain Dev. 2009;2:156.Google Scholar
  61. 61.
    Sharp A, Høj S, Wheeler M. Proscription and its impact on anti-consumption behaviour and attitudes: the case of plastic bags. J Consumer Behav. 2010;9:470–84.  https://doi.org/10.1002/cb.335.CrossRefGoogle Scholar
  62. 62.
    Dikgang J, Leiman A, Visser M. Analysis of the plastic-bag levy in South Africa. Resour Conserv Recycl. 2012;66:59–65.  https://doi.org/10.1016/j.resconrec.2012.06.009.CrossRefGoogle Scholar
  63. 63.
    Dikgang J, Visser M. Behavioural response to plastic bag legislation in Botswana. S Afr J Econ. 2012;80:123–33.  https://doi.org/10.1007/s10640-006-9059-2.CrossRefGoogle Scholar
  64. 64.
    Brooks AL, Wang S, Jambeck JR. The Chinese import ban and its impact on global plastic waste trade. Sci Adv. 2018;4(6):0131.  https://doi.org/10.1126/sciadv.aat0131.CrossRefGoogle Scholar
  65. 65.
    Wang W, Themelis NJ, Sun K, et al. Current influence of China’s ban on plastic waste imports. Waste Dispos Sustain Energy. 2019;1:67.  https://doi.org/10.1007/s42768-019-00005-z.CrossRefGoogle Scholar
  66. 66.
    Al-Salem SM, Lettieri P, Baeyens J. Recycling and recovery routes of plastic solid waste (PSW): a review. Waste Manag. 2009;29:2625–43.  https://doi.org/10.1002/actp.1994.010450207.CrossRefGoogle Scholar
  67. 67.
    Sharuddin SDA, Abnisa F, Daud WMAW, et al. Pyrolysis of plastic waste for liquid fuel production as prospective energy resource. IOP Conf Ser Mater Sci Eng. 2018;334(1):012001.CrossRefGoogle Scholar
  68. 68.
    Buekens AG, Huang H. Catalytic plastics cracking for recovery of gasoline-range hydrocarbons from municipal plastic wastes. Resour Conserve Recycl. 1998;23:163–81.  https://doi.org/10.1016/S0921-3449(98)00025-1.CrossRefGoogle Scholar
  69. 69.
    Mastellone ML. Thermal treatments of plastic wastes by means of fluidized bed reactors. Italy: Second University of Naples; 1999.Google Scholar
  70. 70.
    McCaffrey WC, Brues MJ, Cooper DG, Kamal MR, et al. Thermolysis of polyethylene/polystyrene mixtures. J Appl Polym Sci. 1996;60:2133–40.CrossRefGoogle Scholar
  71. 71.
    Bockhorn H, Hornung A, Hornung U. Stepwise pyrolysis for raw material recovery from plastic waste. J Anal Appl Pyrol. 1998;46:1–3.  https://doi.org/10.1016/S0165-2370(98)00066-7.CrossRefGoogle Scholar
  72. 72.
    Wong HW, Broadbelt LJ. Tertiary resource recovery from waste polymers via pyrolysis: neat and binary mixture reactions of polypropylene and polystyrene. Ind Eng Chem Res. 2001;40:4716–23.  https://doi.org/10.1021/ie010171s.CrossRefGoogle Scholar
  73. 73.
    Smolders K, Baeyens J. Thermal degradation of PMMA in fluidised beds. Waste Manag. 2004;24:849–57.  https://doi.org/10.1016/j.wasman.2004.06.002.CrossRefGoogle Scholar
  74. 74.
    Al-Salem SM. Energy production from plastic solid waste (PSW). In Plastics to Energy, William Andrew Publishing, 2019; pp 45–64.Google Scholar
  75. 75.
    Themelis NJ. An overview of the global waste-to-energy industry. Waste Manag World. 2003;3:40–8.Google Scholar
  76. 76.
  77. 77.
    Verma SS. Roads from plastic waste. Indian Concr J. 2008;3:43–4.Google Scholar
  78. 78.
    Naskar M, Chaki TK, Reddy KS. Effect of waste plastic as modifier on thermal stability and degradation kinetics of bitumen/waste plastics blend. Thermochim Acta. 2010;509:128–34.  https://doi.org/10.1016/j.tca.2010.06.013.CrossRefGoogle Scholar
  79. 79.
    Rokdey SN, Naktode PL, Nikhar MR. Use of plastic waste in road construction. Intl J Computer Appl. 2015;(0975–8887).Google Scholar
  80. 80.
    Poulikakos LD, Papadaskalopoulou C, Hofko B, et al. Harvesting the unexplored potential of European waste materials for road construction. Resour Conserv Recycl. 2017;116:32–44.  https://doi.org/10.1016/j.resconrec.2016.09.0080921-3449.CrossRefGoogle Scholar

Copyright information

© Zhejiang University Press 2019

Authors and Affiliations

  1. 1.Department of Pure and Industrial ChemistryUniversity of Port HarcourtPort HarcourtNigeria
  2. 2.15791 Pebblebrook DriveBellevilleUSA
  3. 3.Department of Oil and Gas ChemistryUniversity of AberdeenAberdeenScotland, UK

Personalised recommendations