2 .1 Introduction
This chapter gives a review of concepts used in the study and reviews various studies concerning solid waste recycling practices around the world. Conceptual framework and literature reviewed were derived from journal articles, workshops/conferences/seminars reports, empirical studies reports and online resources. Most of these sources were accessed through the Internet.
2.2 Conceptual Framework
Conceptual framework is an analytical framework which offers a logical structure of connected concepts that assists in proving a mental picture of how ideas relate to each other in a research and in the real world. It also gives an opportunity to specify and define concepts related to the problem (Luse et al., 2012).
2.2.1 Recycling Industry: An Overview:
Solid waste recycling industry has been in existence for a very long time worldwide. According to Binda, (2014) the industry is as old as the history of mankind with evidence of recycling dating back to 400 BC. Choi (2012), states that the industry has traditionally been recognized as a local service and fringe industry. Little attention was paid to its existence as it was simply associated with marginalized poor members of society. Choi (2012) and BIR (2009) pointed out that the industry is becoming part of societies for two reasons namely as a source of raw materials and as a solid waste management a strategy.
From a historical perspective, development of the recycling economy was strongly encouraged following the World Conference on Environment and Sustainable Development held in Rio de Janeiro in 1992, known as the Rio Summit, taking heed of the 1960-1970s environmental movements’ criticism of the practice of disposal-based waste management. Waste produced was either thrown away, burnt or buried as it was regarded useless mass of material. Environmentalists movements were of the opinion that waste was made up of different materials that should be treated differently i.e., reused, recycled, composted than to be discarded (Schall,1992 as cited in Gertsakis ; Lewis, 2003). The Rio Earth Summit of 1992 advocated for sustainability in solid waste management as well as resource efficient; 21st Green Economy in order to protect the environment.
2.2.2 Recycling and Sustainability
The need to avoid unsustainable activities, has become a leading theme worldwide according Phillips ; Pittman (2009) prompted by concerns such as climate change, resource depletion, pollution, loss of species and ecosystems and poverty among others. The term ‘sustainable development’ entered the public debate after the World Commission on Environment and Development published their landmark report ‘Our Common Future’ in 1987(Gertsakis ;Lewis, 2003). Despite the extraordinary influence of the sustainable development concept, Phillips ; Pittman (2009) claimed that no perfect definition of the term has emerged. However, the most widely used formulation is the one published in the report ‘Our Common Future’ which defines sustainable development as “development that meets the needs of the present without compromising the ability of future generations to meet their own needs.”(World Commission on Environment and Development (WCED), 1987 p.43 as cited in (Gertsakis ;Lewis, 2003). The Rio Summit of 1992 and Agenda 21 emphasized the importance of sustainability in economic development as well as waste management. For example, more efficient industrial operations as well as holistic waste management practices.

The argument put forward was that the increase of waste generation and its management should be given priority while economic development continues. This advocation followed the realization that poor solid waste management can create negative environmental and health impacts(Hoornweg; Bhada-Tata, 2015; Nathanson, 2015).
2.2.3 Recycling and Waste Management
While recycling is considered a source of raw materials after processing, it is also seen as a waste management strategy. There are a number of relevant waste management principles that contribute to reduced waste volumes. Recycling is one among others such as waste avoidance, reduction and reusing as depicted.
Source; Nagabooshnam, 2011
Figure 2.1: Waste Management Hierarchy
According to the waste management hierarchy, figure 2.1, the most preferred options for solid waste minimization are source reduction followed by re-use of products, recycling of materials, resource recovery in the form of material and energy, incineration and finally least preference for land filling. The waste hierarchy is a concept that promotes waste avoidance ahead of recycling and disposal. Its origins can be traced back to the 1970s, when the environmental movement started criticizing the practice of disposal-based waste management(Gertsakis ;Lewis, 2003).The waste management hierarchy concept is now extensively used in many countries as a guiding principle for waste policy and programmes as noted by (Gertsakis ; Lewis, 2003).
2.2.4 Motives for Recycling
Drivers for recycling have been identified as environmental, economic, legal and social. Sukholthaman (2012) observed that recycling occurs for three basic reasons: altruistic reasons, economic imperatives and legal considerations. In both developed and developing countries, recycling is being promoted for economic and environmental reasons (Binda, 2014). Economic imperatives
Economically, one of the major driving forces for solid waste recycling is that it is a cost cutting measure. In both developed and developing countries, waste management has been observed to chew a lot of money from local authorities. For example, in developing countries, waste collection and treatment affect highly the economy of local authorities. Waste management is predicted to consume about 30 % of the local authorities’ budgets in developing countries. (Henry, et al., 2006 as cited in Lindell, 2012). Waste collection is the most costly activity of waste management, predicted to stand for 60-75 % of the total waste management costs (Nemerow, et al., 2009 as cited in Lindell 2012).
On the other hand, growing demand for raw materials has also influenced the drive towards more recycling discarded products. According to Hilpert & Mildner (2013) emerging economies such as Brazil, China, and India have joined the major industrial nations of North America, Europe, and Japan as the principal consumers of natural raw materials due to high demand of produced commodities. In order to meet the deficit, industrial strategies to escape this position include turning to importation of raw materials, stockpiling reserves, technological innovation, as well as recycling of end-of-life products such as cars to get much needed raw materials like steel. Koehn (2011) also highlighted that recycling was becoming one of the solutions to getting secondary raw materials. For example, he reported that around 34% of all global steel production is recycled material with Germany already producing 47% of it. Urban mining which involves the recovery of secondary raw materials from municipal waste is increasingly becoming an important concept in securing sustainable raw materials supply from domestic sources. In addition, recycled materials are considered cheaper than virgin raw materials UNEP (2013). Altruistic reasons
Altruistic reasons include protecting the environment and conserving resources. In addition to the growing scarcity of natural virgin raw materials, increasing volumes of solid waste generation is one of the contributory factors for recycling worldwide, according to Smith (2012). Although, the quantity of solid waste is increasing, the composition is also becoming more and more diversified with serious implications particularly in developing countries where disposal of solid waste is poor and not managed well (UNEP, 2015;UN-Habitat, 2010). Environmental pollution can occur through leaching of dumping sites and landfills, or by air pollution through burning waste. It is also a health hazard to the public and more so for workers and animals that get in direct contact with the waste (The World Bank, 2012). The need for environmental protection and resource conservation is being promoted at international level in order to ensure the respect for environmental values for the benefit of humanity now and in the future.

All these highlighted issues point that sustainability in waste management is a necessity than an option in dealing with waste (Chukwunonye & Clive, 2012; Modak, 2011; Williams, 2009). Chukwunonye & Clive, (2012) emphasized that recycling will not only benefit the present but the future generations as well. Legal considerations

If government requires recycling to be provided for, it imposes a wide variety of economic and civil penalties as incentives to encourage the practice. During the last decades, environmental concerns have been high on the legal agenda according to Ruppel (2013) due to growing pressure on the environment on which life depends on and fears that if this is left unchecked, it can result in more challenges for the future. In most cases, legal considerations have been a response to growing public demand to support the recycling initiative. Developed countries have established legal frameworks for their recycling industries. For example, Extended Producer Responsibility principle is mandatory. The concept of extended producer responsibility originated in Europe and applied to the management of packaging waste in countries such as Sweden, Taiwan and Germany in the late 1980s and early 1990s respectively. EPR is an approach in which a producer’s responsibility for a product is extended to the post-consumer stage of the product’s lifecycle, including its final disposal. There is a shift in attention from waste to product as Rodic (2015) states. The policy today also applies to the management of waste electrical and electronic equipment (WEEE) in the EU through the 2002 EU WEEE directive).
In line with the polluter pays principle (PPP), EPR shifts the physical and financial responsibility for the environmental impacts (waste) associated with products throughout their lifecycle from society as a whole (and municipalities in particular) toward the generators of waste e.g. manufacturers, importers, distributors and retailers and consumers. EPR aims to ensure that the external costs associated with products throughout their lifecycle (including final disposal) are internalized in the costs faced by waste generators and therefore to provide incentives to both producers and consumers to change their behavior in ways that shift waste management up the waste hierarchy. Table 2.1 highlights some of the instruments used to implement the EPR principle.
Table 2.1: Policy instruments under the EPR umbrella

Category Examples
Regulatory instruments • Take–back programs (mandatory or voluntary), including the provision of infrastructure;
• reuse and recycling targets;
• minimum product standards;
• prohibitions of certain hazardous materials;
• disposal bans;
• mandated recovery/recycling obligations
Economic instruments • Product taxes,
• input/material levies,
• Virgin material taxes,
• collection and disposal fees,
• deposit-refund schemes,
• subsidies and tax/subsidy combinations
Information instruments; • Environmental reporting;
• Environmental labeling;
• Provision of information to consumers, collectors, recyclers, etc.
Source: Nahman, 2009 Social imperatives
Communities are known to appreciate waste disposal methods such as land-filling, incineration and composting. However, they were found to be aware of some of the environmental challenges they are associated with. For example, modern landfills were found to have the potential to produce negative social impacts. Thus, at the municipal level, recycling and waste reduction programs are generally influenced by community participation and health-related reasoning. According to research, recycling efforts are still low in developing countries due to low public participation. Possible explanations for this are that people do not separate wastes, infrastructure for waste separation is not in place, the waste collection system does not corresponded to recycling practices, and there are limited recycling technologies (Sukholthaman, 2012).
According to Ezeah et al., (2013) recycling provides employment and a livelihood for impoverished, marginalized and vulnerable social groups that survive in a very hostile social and physical environment. The same idea is supported also by Manhart (2011) studying informal e-waste management in Lagos, Nigeria, that recycling does not require specific skills and is open to poor migrants from rural areas.
2.2.5 Product Life cycle models (cradle-grave)
Recycling comes at the end of the useful life of a product. It can take different approaches or models, namely: Avoided Burden Model involving repair and reuse; Avoided Burden End of Life Recycling Model which includes selling or throwing away; Cut-off Model consisting of recovering material for recycling; and Economic Allocation Model which market driven as explained below (Olivetti et al. (2009). Avoided Burden Method of Recycling
Worn out materials are not usually thrown but ways of prolonging the lifespan of the item are considered. This involves activities like upholstering or refurbishment of items like sofas in order to avoid the burden if the product is no longer useful. According to the waste management hierarchy this form of recycling is termed re-use. Avoided Burden End of Life Recycling Model (EOL)
Products which have reached end of useful life are usually discarded by the initial owner. The initial owner disposes the products because he/she no longer sees value in it. Such products usually end up being sold or recovered by waste pickers either at curb side or at dump-sites and re-modeled into new products for further use. The Cut-off Method
Waste recyclers are usually involved. They sort recyclable waste from the general waste before throwing away what is deemed as useless. The recyclable waste goes through reprocessing procedures before producing new products. Economic Allocation Model
If the market is unsaturated, any materials can be destined for the market. However, when the market is saturated or fully developed (Olivetti et al., 2009), the marketers seek for unique recyclable materials with more value in order to enhance profitability due to increased competition. Such material as scrap metal and e-waste recycling give a competitive edge for the recyclers.
2.2.6. Nature of Solid Waste Recycling
Waste can be any unwanted material that is due for discarding. Technically, waste is considered as a resource in the wrong place according to (Abdullah, 2011 as cited in Muhammad & Manu, 2013). As earlier on mentioned, recycling is a process that involves processing waste into other useful material. In this study, the working definition of recycling is that it is a chain process of collecting and processing of used materials that would otherwise be thrown away as trash and turning them into new raw materials and products according to (Schultz et al., 1995as cited in Ali , 2008). Recycling involves reuse as well as recovery. Reuse involves the process of recovering waste materials intended for the same or different purpose. On the other hand ,recovery means the process or act of reclaiming or diverting waste materials for purposes of being reused or recycled but excludes the use for energy generation (City of Windhoek Solid Waste Management Policy, 2009).
Handling of recyclable waste is associated with both formal and informal sectors in the industry throughout the world, as illustrated in Figure 2.2.
2.2.7 Recycling Chain process
Recycling is represented in three steps depicted by three chasing arrows as shown in figure 2.3 called the universal recycling symbol. This was introduced by Anderson in 1970 as a way of raising awareness of environmental issues. Hickman (2009) defined recycling as process involving three major steps: Step1: collection and processing, Step 2: manufacturing and Step 3: purchasing of recycled products.

Figure 2:2 Recycling Network Players
Source: Viljoen, Schenck & Blaauw; 2012

Source: Hickman (2009)
Figure 2:3 Recycling loop

Boguski et al., (1994) identified two main types of recycling processes closed-loop and open-loop. Closed-loop recycling is a process in which the material of a physical product is recycled into the same product, a process that may-in theory-be repeated endlessly. On the other hand, open-loop recycling involves the conversion of material from one or more products into new products involving a change in the inherent properties of the material itself.
Figure 2.4 shows a more detailed diagram of the recycling process derived from the recycling loop. Whichever, process used close or open recycling loop is represented in the same manner.

Source: WBCSD (2011)
Figure 2.4: A standardized model for the sustainable value chain.

Like any other industry, these processes involve value addition chains carried out within the steps highlighted earlier and associated benefit chains. Solid waste recycling value addition Chain
Value chain concept was introduced by management expert Michael Porter in 1985. The value chain process describes the full range of activities which are required to bring a product or service from conception, through the different phases of extraction, collection, processing, production, delivery to final consumers (ADB, 2014) but excludes use by consumer and eventual discard is depicted in recycling value addition chain. The idea is getting the product closer to the consumer (Bohr, 2007) by improving its presentation, transportation, storage, packaging, labeling, processing as well as marketing
A variety of materials e.g. plastics, paper, bottles and textiles can be discarded by individuals or entities because they are no longer desired. Solid waste recycling as a value addition chain begins with materials collection and ends with usage of recycled product according to Hickman (2009). Following material discard, comes material collection and storage which can either be through public or private collectors; processing which involves sorting, cleaning, shredding, crushing, compacting or baling or similar operations to increase the bulk density of secondary materials in order to reduce transport costs in a way that is acceptable to the end user and finally production of raw material; manufacturing which involves production of new products, depends on material type e.g. recycled cardboard and newspaper are used to make new boxes, papers, and other prod¬ucts such as tissues, paper towels, toilet paper, diapers, egg cartons and recycled plastics used for soft drinks, juices, and peanut butter containers etc. After manufacturing, products are distributed to different customers for selling. The recycled raw materials and products are bought and sold just like any other commodity, and their prices change with the market fluctuations.
The following highlights these processes within the facilities generally provided in the recycling process.