9 CHAPTER II LITERATURE REVIEW This chapter provides the literature review on the main topics of this thesis: plastic waste management and system dynamic modeling. The purpose of this chapter is to introduce the topics approached in this thesis. Section II.1 presents the concept waste management. Section II.2 provides the more specified concept of waste management, especially plastic waste. Section II.3 gives a summary of the plastic recycling process. Section II.4 explained about system thinking approach which will be focusing on system dynamic modeling as one of the system thinking approach method. Section II.5 is briefly summarized the system dynamic implementation in waste management in various countries from time to time. Section II.6 is a summary of research that are closely related with this thesis and also explained the position of this thesis. Finally, in section II.7 consists of significant findings of this thesis. II.1 Waste Management The initiation of waste management study was already begun years ago, triggered by the arisen of environmental problem. When the studies and investigations of local disaster found that the main cause is by the long term effect of unhealthy lifestyle and consumption, government started to change policies in order to suppress the amount of waste created in daily activity and industrial production process. So it is not big news anymore when most of the waste generation was not coming from industrial activity, but from daily activity and consumption. The proportion of the contribution shockingly was as significant as the amount of waste generated by the industries in one single area. The significant escalation of waste amount in many countries is not only the effect caused by lifestyle. This environmental issue is also the implication of the previous policy that unnoticeably was directing society consumption pattern and 10 lifestyle into a worsening pollution due to waste created by it. This problem was first time occurred in US government. Figure II-1 Paradigm Shift in Waste Management Policy (United Nation Report, 2008) Many previous policies in US were created to establish clean living condition as the main objective. To meet this main objective, government created policy that was focused on reduction, recycling, treatment and disposal. However, the material used for creating the products are mostly non degradable. Also, at that time, the public lifestyle in consumption has not yet adjusted to the green living concept either. Thus, the amount of waste in the landfill became rapidly increased because of the non-degradable waste. But then years later, after several research and studies conducted, government started to realize that the previous policy was not preventing the root cause of pollution, but merely reducing the amount at the landfill. People also started to realize about this fact and the danger of abundant amount of waste on landfill. And for the last ten years, the public’s environmental awareness has significantly 11 increased, and studies about waste management also have been started to develop. As the response to this issue, government started to modified and reconstructed the policy structures to one that is focused on recycling, energy harvesting, and the improvement of treatment and disposal method. Spreading the news about the issue was also one of the strategies that the local government did to gain support from the community. As some studies were conducted, there are many concepts of waste management that has been developed. Englade and Jin in 2006 invented the application of biotechnology in waste management for sustainable development of resources with emphasis on biodegradation of industrial pollutions. Also, in 2006, Georgakellos has developed a new conceptual framework using life cycle assessment (LCA) polygon framework for environmental evaluation in waste management. In his study, he found that recycling strategies can, in most cases, reduce the total environmental burden of the glass container examined. When most of the waste management studies are developed using the quantitative approach, Aung and Arias (2006), were conducted a study about waste management study case, using different approach by focusing in the behavioral framework of waste management in San Pablo del Lago, Ecuador. They combined qualitative and quantitative methods to examine the environmental practice in Ecuador. Several studies that are focusing on the construction and demolition of waste management are also become high interest for some researchers. As highly known, China is one of the highest industrial countries in the world, causing the level of pollution significantly higher than any other developed countries. Triggered by this issue, various studies focusing on the industrial waste were conducted. Hao, et al. in 2007, studied about the construction and demolition waste management in Hong Kong using simulation model approach. And again, Hao et al. conducted another study about the construction and demolition waste management in Shenzhen, China using dynamic modeling approach in 2010. 12 In Indonesia, the development of the waste management system are mostly focusing on the recycling and reducing the amount of waste generated from daily activity. Irawati et al. (2009), conducted case study of industrial waste concept as the urban waste management in Bandung. The research focused on four main programs, which were waste reduction, recycling and composting maximization, public services improvement, and promoting the waste management program to improve the public awareness. Deradjat and Chaerul in 2009, also studied about waste management in Bandung city, Indonesia. The study focused on the evaluation of solid waste transportation in northern Bandung area as their study case. From that study, the authors found that the waste transportation services level in North Bandung area is still small, the percentage of landfill capacity to daily generated waste only reached 63.8%, while the percentage of transportation facilities capacity to daily generated waste only reached 51.9%. However, the scope of waste management study is very broad and various. Some studies about waste management are focused on one certain category or type of waste itself. Pongrácz and Pohjola in 1997 created a waste taxonomy by dividing it into 4 different classes below. Table II-1 Waste Taxonomy (Pongrácz and Pohjola, 1997) Class Description Class 1 Non-wanted things, created not intended, or not avoided, with no purpose. Class 2 Things that were given a finite purpose, thus destined to become useless after fulfilling it. Class 3 Things with well-defined purpose, but their performance ceased being acceptable due to a flaw in their structure or state. Class 4 Things with well-defined purpose, and acceptable performance, but their users failed to use them for their intended purpose. The taxonomy of waste in Table 1 was formulated using an object oriented modeling language, PSSP™, which is based on the ontological commitment that every real thing can be formalized as an object having four attributes: Purpose, Structure, State, and Performance (Pohjola and Tanskanen, 1998). 13 But based on the form of the waste generated in daily and industrial activity, it can be categorized as three types; liquid waste, gasses waste, and solid waste, depending on its physical state. From all three types, it is solid waste that became the problem in damaging the environment, since the most materials in solid waste cannot be degraded naturally without special treatment. One of the developed countries that has been try to implement the integrated solid waste management practice is United States (US). In US, the total amount of solid waste produced everyday has become a great problem, as the Americans tend to have a very high consumption rate of packaged goods and instant foods, and most of it was in plastic forms. As the result, the escalation of solid waste was occurred in such short period of time. To suppress the adverse impact of solid waste problem, a better waste management chain has been developed and implemented. The government also increased the efficiency of land resource utilization. The improvements have delivered some substantial progress and result, declining the solid waste produced in US. II.1.1 Solid waste generation and characteristics As discussed in previous section that one of the most anticipated types of waste is solid waste, such as metals, plastic, wood, paper, and other waste that generate from business, hospitals, schools, stores, and daily activities. As we know, solid waste is very different compared to the organic or other non-solid waste. Solid waste is far more difficult to be treated and degraded into natural environment or other usages. Some materials from solid waste even cannot be reuse in production process or treated into recycling process. Thus, solid waste management system is very important to improve for the global future. For every country, solid waste produced may have different characteristics from one to another. Former studies have shown that solid waste characteristics in Nigeria are similar to those of other third world countries (Pickford, 1983; Chefetz et al., 1996). Nwankwo (1994) classified solid waste in Nigeria into three basic categories, namely: 14 1. Residential which include commercial, homes, stores, hotels and restaurants. 2. Municipal which include streets, sidewalk and alleys. 3. Industrial which include factories, power plants, construction sites, sewage treatment plants, septic tanks and vacant plots. Nwankwo also noted that municipal or urban solid waste comprised of 55% paper, 21% food waste, 7% glass, 4% wood, 5% residence wastes, 5% plastic and 3% others. Since the highest proportion of solid waste is generated from daily human activity, it is likely that the number of population holds an important role in controlling the amount of solid waste created in a particular space. Even though the industrial waste generation holds high impact in the environmental damage cause, but the actual destructive components from industrial waste are coming from the non-solid waste. The solid waste generated by industrial itself are still less than the amount of solid waste created by daily public activity. This is the underline reason that the research is only focused in residential solid waste management, particularly plastic waste. In 1997, for instance, Americans generated 198 million metric tons of municipal solid waste. This means Americans produced approximately 727 kilograms per person or, nearly 2 kilograms per person per day. As in 1991, Port Harcourt estimated population of Port Harcourt is about 1,356,000 (Federal Office of Statistics, 2003) with an estimated municipal solid waste (category 1-3 above) generated as around 1,393,880 kg/day with each of the zones in the metropolis on average generating 199,126 kg/day with approximately 1.03 kg/person/day (Ayotamuno and Gobo, 2004). II.2 Plastics Waste Management Plastic is one of the most anticipated types of waste generated in daily activities. As the easiest material to be produced in a mass production scale with the lowest 15 cost required is plastics, the world has become the place where plastics waste is become the getting higher day by day. As the technology improved, new plastics materials and the application of plastics material usage is also increased and begin to be the substitution of metal and other materials. This broader usage of plastics materials has increased the throw-away plastic packaging and other household usage. In order to reduce the accumulation of plastic waste in landfill, plastic waste recycling and remanufacturing system are highly required. Especially in urban area such as Bandung, where the population growth are increase rapidly and the consumption rate per person are significantly higher. In Indonesia, the usage of plastic form itself has become daily need. The low production cost of plastic is the main consideration of manufacturing industries in Indonesia to use plastic as the main component. Badan Pusat Statistik (BPS) data shows that in 1995, volume import of plastic sales, mostly polipropilena (PP), is 136.122,7 tons. As in 1999, the number has significantly increased 34,15%, become 182.523,6 tons. And the number has been continued growing ever since. As the consequence, the escalation of plastic waste was inevitable. Hartono (1998) studied that the average proportion of plastic waste generated in daily activity by one person in Indonesia is approximately 9,3% of waste. That number is most likely will be increased as well as the population is continued to grow. And as stated before, since plastic is a non-degradable form, the growth of plastic waste become a major problem for the environment. II.3 Plastics Recycling Process Basically, plastic consists of two major types, thermoplastic and thermoset. Thermoplastic is plastic form that can be remanufactured or reshaped again easily depending on the needs.