In the past 45 years Saudi Arabia has experienced the two paired factors that guarantee a very rapid increase in the amount of municipal solid waste (MSW) that must be managed. The two factors are rapid population growth in large cities, urbanization, and an increase in amounts of solid waste generated with rising standard of living levels (Ouda, Cekirge & Raza, 2013). Fossil fuel products are the most popular energy source around the world; Saudi Arabia holds large resources of oil reserves. Saudi Arabia produces the most crude oil in the world and the country has invested revenues from oil sales for the last four to five decades into social and economic development in the country.
The country demonstrates a consistent rate of average annual population growth of 3.4 percent that started in the mid-1970s and remains at that rate today. The rate of average annual population growth is expected to remain the same in the future because of the Saudi culture’s social, economic, and reproductive behavior (Ouda et al., 2013). In 2010 the population of the country was approximately 2.7 million individuals and by 2032 the amount is expected to double (Ouda et al., 2013). Sixty two percent of the population lives in the six largest cities that now are home to about 62 percent of the country’s population. Saudi Arabians generated about 13.8 million tons of MSW in 2012 and the projected quantity for 2032 will be close to double, 26.9 million tons. Historically landfilling has been the usual method for municipalities to deal with MSW but that method has “environmental and financially negative consequences” (Ouda et al., 2013, p. 403).
The population is expected to continue generating solid wastes while at the same time increasing the demand for electricity. Fortunately, the two problems can be merged into one solution. MSW is used in other countries to generate electricity which is transmitted immediate to the local grid. The solution is logical and regional, but incredibly complex. Therefore, the research proposes to develop a Systems Engineering Integrative Project to offer a method for transforming Saudi Arabia’s waste problem into energy. Marshall and Farahbakhsh (2013) cautioned that most systems analyses have not been able to achieve “a broad systems perspective for solid waste management (SWM)” (p. 988). On the other hand, no other strategy can deal with the complexity of municipal solid waste management (MSWM) as well as an engineering systems process approach. Therefore, tackling the problem of MSW from a systems approach for Saudi Arabia is the best option.
Saudi Arabia has the advantage of reviewing practices in other countries that successfully use integrated solid waste management (ISWM) and convert waste to energy. The three general categories that must be addressed to initiate a holistic problem solving approach include (a) identifying the technical solutions that are suitable for the culture, (b) discerning the organizational capacity of the locals in order to enhance organizational needs at the local, province, and national levels, and (c) identifying all the stakeholders who are part of the (ISWM) solution (Marshall & Farahbakhsh 2013).
- Use the systems engineering management process to build a design of MSWM for Saudi Arabia.
- Identify the lean management strategies with the best potential to work well for MSWM in Saudi Arabia.
- Examine the cultural and ethical issues related to the project.
- Compare waste management practices of other countries to identify strategies that can be adapted to Saudi Arabia.
- Identify and analyze solid waste management practices and techniques appropriate for Saudi Arabia.
- Describe the benefits of linking strong governmental legislations, financial support, public awareness, modern technologies and stakeholders’ participation in order to successfully manage the MSW.
- Demonstrate the systems engineering management method that may potentially alleviate the burden of Saudi Arabia’s MSW.
The project starting in September and continuing into November use both quantitative and qualitative methodologies to address the urgent problem of Saudi Arabia’s SWM. Systems Engineering Management process is used to develop an IMSM program appropriate for Saudi Arabia. All stakeholders will be identified and each part of the process will be considered from a Life Cycle perspective. A Life Cycle perspective, for example, considers the raw materials to the end-of-use for products. Solid waste is a part of the life cycle for the materials but the initial form of the raw materials allows an informed management process to be developed. The cradle-to-grave, reduce, reuse and recycle techniques will be evaluated. The Lean Six Sigma management theory is described and applied to the project. A literature review is carried out to better understand the status of MSWM in Saudi Arabia, the systems process approach and the use of Lean Six Sigma management compared to other management philosophies. A quantitative assessment of data on Saudi Arabia’s MSW is carried out by using data from secondary sources.
The following systems steps are part of the development of the MSWM plan for Saudi Arabia.
- Explanation of engineering systems process as applied to the project.
- Discussion of systems management and providing a definition by using inductive derivation of definitions from experts.
- Determine a trade process to provide balance to the system.
- Define risk management and identify the risks inherent in the system.
- Establish the assumptions used and describe the reasoning.
- Show how quality management will be integrated into the process.
- Demonstrate how lean management strategies improve the system.
- Address the issues of systems integration.
- List the essential requirements for verification of the system.
Engineering process management is used to evaluate the tasks necessary to alleviate the MSW problem in Saudi Arabia and offer a solution that can also meet the growing demands of high levels of waste generation. Systems engineering process management is defined, the quantities and characteristics of Saudi Arabia’s MSW are evaluated, successful waste management processes in other countries are reviewed, and a recycling process appropriate to Saudi Arabia is developed and presented. Qualitative and quantitative methodologies are used to carry out the research.
Chapter 2 consists of a systematic literature review of topics that offers an improved understanding of the status of MSWM in Saudi Arabia and from a global perspective. The definitions for solid wastes, engineered system process management and lean management are included, as well as thorough discussions on each of the topics. Sources of solid waste and solid waste management strategies are reviewed including recycling, materials, landfills and waste-to-energy (WtE). The advantages and disadvantages of MSWM techniques are discussed from the perspective of the potentially best technique for Saudi Arabia. MSW generated in different countries of the world will be discussed in order to recognize how Saudi Arabia compares to other countries. The use of integrated solid waste management is discussed from engineering systems process and lean management perspectives. Systems process and the efficiencies of lean management are described in detail. The first section presents an overview of MSW globally and in different countries in order to understand that MSWM must be prioritized for the public health and safety.
Global Overview of MSW
The high rate of generation of waste for some countries in the Middle East and North Africa (MENA) is higher than any other parts of the world. The reason in countries like Saudi Arabia, UAE, QATA, Bahrain and Kuwait is the high revenues from oil and gas production as well as revenue from industry and construction is invested back into the region. The government investment is an investment in the people that has increased the economic level of the populations. The capability of more purchasing power leads to more consumption; and more consumption leads directly to higher waste generation rates. In the five Arabian countries mentioned above the amount of waste produced has been reported at as high as 2 kg/capita waste per day (Saraf, 2014). For an idea of how this compares with the rest of the world, in 2001 the amount for the U.S. was 2.2 per capita/day, for the Netherlands was 1.4 per capita/day and for Poland was 0.71 per capita/day (Sorum, 2001, p. 7).
The highest waste generating countries are also the countries with the highest gross domestic product (GDP). (See fig. 1) The GDP is considered an indicator of quality of life and standard of living. Although from a municipal solid waste manager’s point of view, the countries with the highest GDP are in danger of the negative repercussions of waste generation unless integrated solid waste management is seriously applied. In figure 1, Saudi Arabia is shown to have an average 1.0 to 1.49 kg per person/day waste generated, but this is an average across the entire country including both metropolitan areas and rural areas.
The amount of waste generation in Saudi Arabia in cities is causing a crisis that will only worsen the longer the national, regional and local municipalities delay instituting sustainable, long-term solutions. Urbanization is the migration of individuals from rural areas to cities. As the population increases in cities the burden of municipal solid waste worsens. The World Bank (2012) reported that municipalities around the world on average generate approximately 1.3 billion tonnes of MSW/year. The amount calculates to approximately 1.2 kg per city resident per day. As the discussion below makes clear, 1.2 kg per city resident/day is an average for the entire country because the amount doubles in Saudi Arabian urban areas.
Global amounts of municipal waste collected per capita served were reported by the United Nations. (See fig. 2-2) The U.S. is the only country at the largest rate, 701 to 1650 kg per capita served for MSW collection. Several European countries are at the next lowest rate, 601 to 701 kg/capita. (See fig. 2-2) Many countries have yet to record data on the topic, including Saudi Arabia. The map of MSW collected per capita globally is especially interesting compared to the map of the amount of municipal waste collected globally and the total population served.
The amount of municipal waste collected is the greatest in Russia, China and Brazil the three largest countries in the world. (See fig. 2-3) The United States shows the same amount of 50 million tonnes to 223 million tonnes of municipal waste collected as the three largest countries.
The total population served by municipal waste collection, unfortunately, is not reported for every country. The U.S. and most of Western Europe are in the 90 to 100 percent range. Most of South America is in the 80 to 90 percent range; but only one country in Northern Africa, Algeria, is in the 80 to 90 percent range. On the Gulf peninsula, Saudi Arabia has no reported data. Yemen is in the 9 to 30 percent range, Syria is in the 80 to 90 percent range, and Iraq is in the 30 to 60 percent range. Considering the amount of MSW generated in the world according to figure 2-3, Saudi Arabia is not alone is needed to develop high quality, workable and efficient recycling strategies.
The economic and social costs of MSW are high because the risks of safety, hygiene, belated clean-ups, treatment, and water and air borne illnesses are high. The World Bank calculated the increase from 2012 to 2025 of waste generated at the same rates. The World Bank’s expectations are low that the situation will improve in urban areas around the world. Figure 1 is a bar graph depicting the expected growth of MSW from 2012 to 2025 in cities. Globally an increase of approximately 0.9 billion tonnes is expected. In China an increase of approximately 880 million tonnes MSW generated annually; in the U.S. the expected increase is approximately 80 million tonnes annually. (See fig. 2-5) Many countries have not yet developed national integrated solid waste.
The OECD member states have varying amounts of municipal waste generation per capita. Japan reported municipal waste generation in 2007 of about 410 kg/capita. (See fig. 2-6) Norway reported the highest amount with approximately 830 kg/capita; more than double of the amount generated in Japan during the same year. (See table 2-1) The U.S. reported 760 kg/capita.
Recycling varies between the 28 member counties of the EU from 2003 to 2012.. The Poland, Finland, Austria, Switzerland, and the Netherlands demonstrated the lowest amounts while France and the UK showed the greatest amount of recycled materials during the nine year period. France and the UK also showed a trend of increased recycling from 2003 to 2012. Poland is one of the poorest countries in the EU 28 and Switzerland is the richest country in the EU 28, yet they both have very low levels of materials recycling. Poland shows that the amount of materials recycled is increasing at a steady, but slow rate. On the other hand, countries that have more money to invest a state-of-the-art national recycling programme are staying consistently at a low level of materials recycling from 2003 to 2012. (See fig. 2-7) Saudi Arabia can learn that developing a culture where recycling materials is appreciated must be developed.
The amounts in thousand tonnes of materials recycled for each country are listed in Table 2-2 by year. The data in table 2-2 shows more clearly how, from 2007 to 2012, Poland approximately doubled the amount materials recycling for their country. The countries that have not made any improvement are Finland, Austria, Switzerland and the Netherlands. However simply looking at the data with no context is misleading. Austria and the Netherlands both are highly respected for their MSW programmes. On the other hand, Switzerland generates the most waste in the EU 28, the country is very rich, but no recycling culture has been developed.
France and the UK demonstrated the most waste treated from 2003 to 2012. (See fig. 2-8) The Netherlands with an excellent record of treating MSW, showed improvement (from approximately 7 million tonnes to 10 million tonnes treated waste) between 2007 to 2008 which was maintained.
Placing waste in landfills in the EU is highly discouraged. The basic reason is the lack of land area to accommodate landfills. The land is needed for other purposes. Figure 2-9 shows the trends in the total amount of waste disposed of in landfills or on top of the land in dumps. The UK demonstrates the most dramatic change from over 25 million tonnes in 2003 decreasing to almost 10 million tonnes placed in landfills. (See fig. 2-9) Poland and France showed slight decreases in the amount of wastes landfilled.
But the lowest landfill rates for waste disposal are in the Netherlands, Austria, Switzerland, and Finland. The four countries land filled less than 3 million tonnes of waste for the period from 2003 to 2012. Meanwhile the rate of composting and digestion increased dramatically in the UK indicating the reason the amount of waste landfilled decreased so dramatically. France shows the highest amount of composting.
Japan is the known as a leader in recycling of municipal solid waste. The land area of the country is small so landfilling is not an option. The Japanese take a systems approach to MSWM. Public policy is monitored in Japan, so macro-level indicators are recorded and goals are set to meet the following features. The circulation which is the cyclical user rate; the value is calculated by cyclical use amount / cyclical amount plus the natural resource input (%). The trend for behavior has been increasing from almost eight percent and the goal for 2015 is 14 to 15 percent cyclical use rate. The input values are defined as resource productivity; calculated by dividing GDP by natural resource input (cost/tonne). Input increased from 1990 20,000 yen per tonne to 35,000 yen per tonne. The goal expected to be reached by 2015 is 420,000 yen per ton. Output is the final treat of waste and is based on the amount of waste placed in landfills (million tonnes). In 1990 the amount of waste placed into landfills was approximately 110 million tonnes; by 2015 the goal is to decrease the amount to23 million tonnes. (OECD, 2003, p. 7)
Food wastes, glass, paper, cardboard and a variety of plastics are the main recycled components in Japan. (Table 2-3) The factors that are taken into account include the ratio of packaging waste in household waste, the production and shipment of packaging, and the recycling rate and the collection rate of packaging waste. The sum of the values associated with the various stages of packaging defines most of the life cycle. If the raw materials were added at the beginning and the disposal details at the end the full life cycle assessment can be evaluated. Packaging is a plastic material that is recycled and the following charts and tables demonstrate the details that are taken into account for recycling plastics in Japan.
Performance indicators for waste management are measured by the amount of waste, the positive impact to global warming, customer satisfaction, and the economy. Some of the indicators are measured in numerical values. Other indicators like customer behaviors are compared from year to year based on qualitative data. Another set of indicators used by the Japanese waste managers are called the ‘effort indicators.
Effort indicators have been set as goals to reach from 2003 to 2010, and more challenging goals were set for 2015. Three measures of gauging the reduction of solid waste are (a) total waste generation per person per day (kg/capita per day),(b) total household waste generation per capita per day, and (c) the waste generation for the business sector that is included in the MSW stream. Residents’ awareness and their behavior of recycling, reuse and recovery are determined. The amount of awareness about recycling in 2003 was already 90 percent. And residents’ who used recycling (recycling behavior) was approximately 50 percent.
Recycling businesses are supported and promoted by governmental and consumer organizations so that the market will increase. Individual stakeholder awareness and behaviors are also recorded. A grocery store keeps track of how many people take plastic shopping bags, how many carry their own cloth bag, and how many choose another option such as not using any bag. Municipalities are stakeholders invested in the success of recycling to save money and provide better public health and safety. Therefore cities keep records of the indicators that are most important in the area.
In 2010, Japanese production of synthetic resins amounted to 4.6 percent of world production. The total global production in 2010 was 265 million. The plastic waste management institute records plastic waste generation and “the macro flow” of Japanese plastic waste (OECD – Intech 2012, p. 2). The amount of PET plastic is large enough to be a large, steady resource for plastic. (See table 2-5) Approximately, 290,000 bottles produced with PET in the general wastes in 2010. Plastics suitable for recycling are in the business sector, car manufacturing, agriculture and home appliances (e-waste). Manufacturing and e-waste need to be treated differently and separated from the MSW stream. Plastic packaging is the largest amount; more than 1 million items of packaging in 2010 were counted. The value of 1 million pieces was calculated by dividing mixed plastics by containers and packaging in general wastes.
The U.S. requires bottles and packaging and other items made with plastics to have the code number on the items. Soft drink bottles are made from PETE, polyethylene terephthalate, having a code. (See table 2-6) Polystyrene is the soft, thick type of plastic often used for foam drinking cups and plates, packaging and plastic forks, spoons and knives. Low density polyethylene (LDPE) is commonly used for grocery bags and diapers.
The heaviest plastic is polyethylene that reported from Japanese wastes as about 30 percent. PET is about 13.8 percent by weight of mixed wastes. Metals were measured as about 2.6 percent weight of mixed plastics. Moisture measured about 7.3 percent of the mixes plastics wastes.
The total plastic generated as waste in Japan in 2010 was about 9.45 million tonnes. (See fig. 2-11) Based on weight percent polyethylene (32.2 wt %) is generated in the greatest amount, next is polypropylene (23.2 wt %), and the third is polystyrene (13.5 wt %). Polystyrene is the foamy type of plastics and was reported as 13.5 wt %. PVC is polyvinyl chloride, a thick plastic suitable for such as drainage pipes and was reported as 9.3 wt %.
The largest number of waste generated plastics is mixed plastics that have been described above. The population coverage recycling PET bottles was reported at 98.5 percent. (See table 2-8) Food trays were recycled by 35.8 percent of residents, and residents who recycled mixed plastics was about 61.1 percent.
Recycled agriculture thin plastics, Polyethylene, PVC and other plastics (tonnes) are compared to the amounts incinerated; land filled, and disposed of in other ways. The largest amount of polyethylene (43,129 tonnes) is recycled compared to the other methods. The highest amount of PVC (30,373 tonnes) is recycled
The systems method of waste management is concerned with costs as well as materials. Waste plastics can be sold to other countries. The municipality (or other entities) selling the plastics pays for the export and loading costs (Free on Board). On the other hand, the buyer pays for the transportation after the items have been loaded on the ship. Mixed plastics were as the largest category sold to buyers out of the country. The mean price/kg for mixed plastics in Japan for 2011 was 43.6 yen/kg.
A case study was carried out in Neyagawa, Japan that measured the different waste fraction in household waste. The total percent of weight and percent of volume were reported Kitchen waste is the largest percent by weight over 20 percent, but by volume glass is less than ten percent. Plastics by weight are about ten percent of the household waste composition, but by volume the amount is closer to 35 percent. (See fig 2-12) The amount of plastic packaging is the largest percent by volume of plastic household waste. That is the reason avoiding items with packaging is an important part of the waste hierarchy.
Another case study in Japan looked at the types and amounts of plastics in garbage bins in Osaka, Japan. Packaging is found in the middle of the graph and the amount represented is 91.4 percent of total plastic wet weight. The balance was reported as other types of household items made with plastic that had been thrown into the garbage bin. Approximately 33 types of items were found and weighed, including empty water sachets, drinking bottles, and hygiene product packaging (like shampoos, drugs, cosmetics, and toothpaste). Products used for cooking such as coffee, tea, soy sauce and spice packaging were all measured. The garbage bags that held the waste measured about 7.5 percent total plastic by weight in the packaging category.
Total MSW by composition is recorded for four more areas in Japan by percent of the total waste composition. The refuse derived solid fuel (RDF) factors listed are important when MSW managers compare incineration to other forms of disposal. The amount of paper and textiles was the largest component reported. The range for the four locations was from 42.0 percent to 62.7 percent. The amount of kitchen wastes ranged from 5.2 percent to 24.1 percent; a low value compared to other global municipalities. The range of plastics and rubber was from 6.5 percent to 27.3 percent. The differences in the four cities were due to the different recycling behaviors of the residents.
The composition of wastes from households in Netherlands was measured in 2008 for households in the country. The Netherlands and Austria are the two most successful EU recycling countries. Organic wastes as food wastes were about 19 percent (calculated from percent volume in kilotonnes). Recovered paper and cardboard equaled about 18 percent, glass was about 5 percent, textiles also measured about five percent and the other waste fractions were calculated to be one percent or less. The results demonstrate the success of the Netherland’s sorting and recycling behaviors. Bins can be found for cans, bottles, paper and other recyclables at advantageous spots in neighborhoods and cities. Householders do a lot of the sorting before the wastes reach the MSW stream.
The amount of MSW generated in Saudi Arabia is approximately 13 million tonnes annually. The amount in Riyadh is reported to be 3.7 million and in Rusaifa is reported at 65,530 tonnes annually.
The waste composition in the Netherlands by percent is 19 percent organic (food) wastes, 18 percent recovered paper and cardboard, 5 percent glass containers, and textiles, PET bottles, and metal packaging, cardboard drinking packages and plastics one percent or less. This indicates the high success of their recycling program.
The results of MSW composition measurements for Saudi Arabia demonstrate that a recycling programme is needed in the country. The highest amount of waste fraction is the organic component which is the food wastes (34 percent). (See table 2-14) The amount of papers was reported as 28.5 percent. (See table 2-14) Plastics make up approximately 5.6 percent. (See table 2-14) Wood accounts for eight percent in the MSW stream, and glass accounts for 4.6 percent. (See table 2-14) The context of the data is that the table does not necessarily reflect the situation in Saudi Arabia accurately; because a consistent, reliable database is not available that holds data on waste generation. Informal scavenging is responsible for much of the recovery, reuse and recycling that is done.
The factors that influence the composition of MSW is categorized based on characterizations of the waste fraction. The character of MSW is dependent upon the culture and affluence of the area, the population density, the rate of new people moving into the area, the types of businesses in the area and even the weather (Laisis 2004). The details that need to be know about the wastes for proper handling include the moisture content, the waste density, the overall composition of the waste, particle size, density, and chemical composition (Laisis 2014). The composition of the municipal waste stream consists of food waste, clothing, paper, cardboard, water sachets, a variety of plastic packing materials and other non-construction and non-hazardous wastes. If hazardous, construction, and demolition materials are in the MSW stream the manger needs to separate the items into other waste streams.
The first notable factor from Table 2-15 is the high percentage of food waste as a component in Beijing, Shanghai, and Hangzhou, three cities in China. The amounts range from 62.83 to 67.10 percent have which is over fifty percent organic matter; therefore the moisture content is high in the MSW of three major cities in China. New York City measured 23 percent food fraction, Singapore measured 25.4 percent food fraction and the average amount in Japan was reported at 19.1 percent. (See table 2-15) The measurements indicate that Japan has the food organic fraction with the lowest moisture. New York City has a large percentage of paper, 27 percent and Singapore has a large percentage of plastic, 25.40 percent. (See table 2-15) Paper and plastic can both be recycled. Each of the locations shows a different percentage MSW fraction of paper, plastic, textile, wood, glass and metal. Based on those values different MSWM practices are needed for each country. Also the types of materials in the category ‘Other’ need to be identified to create a better MSWM strategy because the ‘other’ components from 9.68 percent to 17.09 percent.
The U.S. has the highest waste collected in kg/capita; the amount is about 736 kg/capita. Switzerland is the next highest with the amount 706 waste collected in kg/capita. The Netherlands collects about 613 the UK collects about 529 kg/capita of waste.
Developed countries vary in the priority placed on recycling and waste reduction. Some countries have not taken advantage of integrated solid waste management (ISWM) processes, but some like the Netherlands, have been very successful. Therefore, Saudi Arabia should use as examples the successfully integrated MSWM processes while adapting them to the needs and culture of Saudi Arabia.
In Europe, the Netherlands (aka Holland) and Austria are recognized in 2012 as providing better waste management than any of the other 27 European Union member states (Blair 2012). Limited space for land filling wastes is a common problem around the world, but especially in the small country of the Netherlands with a land area of only 41,543 sq km (The Netherlands 2014). City dwellers make up more than 83 percent of the Dutch population (The Netherlands 2014). The national government agency with oversight of MSWM in Holland is called the Rijkswaterst in Dutch and the Ministry of Infrastructure and the Environment in the Netherlands in English. Beginning in the 1980s the Rijkswaterst started grappling with the problem of solving the MSWM problem without using landfills, because no more land could be dedicated to landfills. The second problem was the high moisture content of the waste due to large amounts of organic matter in residential and small businesses waste streams; the high moisture content did not allow for efficient incineration Rijkswaterstaat (2014).
The final design of the Dutch MSWM process includes reduction in consuming products, recycling, recovery, and WtE integrated with the other necessary activities including collection, transport, sorting, operations and maintenance of solid waste. The WtE essentially transforms waste into energy. The Netherlands increased their energy recovery from wastes by as much as 88 percent using WtE and other energy recovery strategies during the period from 1980 to 2010 (Rijkswaterstaat 2014).
Residential waste from Dutch households in 2008 amounted to approximately 6,942 kilotonnes. (See fig. 2-17) The amounts of organic wastes (mainly food) is about the same amount as the amount of recovered paper and cardboard. Glass containers are next in amount. PET is the largest type of plastic in the Dutch municipal waste stream. Most of the wastes are sorted by the waste generator by placing the appropriate material into labeled recycling bins.
Figure 2-14 shows how the largest amount of waste generated in the Netherlands is organic (food) wastes, but that is removed and used for composting. Therefore it is treated as a recycled, reused and recovered commodity with value. The Netherlands only generates small amounts of metal and glass, plastic, paper and cardboard. The category under ‘other’ is even smaller in the bar for the Netherlands. This indicates the country has a large amount of knowledge and control over the wastes generated. The types of wastes are known and recorded. On the other hand Poland and Norway are European countries that do not match the degree of control and knowledge of the types of MSW generated.
Figure 2-15 shows that from 1992 to 2008 the amount of MSW placed into landfills steadily decreased, while the amount incinerated in WTE plants increased. By carefully controlling the waste generated the Netherlands has avoided the crisis of lack of land for land fills. The country has a culture that has integrated recycling, reuse, and recovery into the daily life cycle. Recycling bins are colour coded so it is easy for residents to sort their waste into the proper bin. The colour code also makes it easier for the waste collector to place the waste from the bins with the right waste component.
The U.S. EPA (United States Environmental Protection Agency) developed a management hierarchy of eight levels (See fig. 2-16). The most desired action is at the top of an inverted triangle. The top level is the largest part of the triangle, because it represents avoidance. Avoidance of generating MSW is the most desired action and requires an individual to plan purchases so that consumer goods with a lot of packaging or items that are not recyclable are avoided. The next two levels under avoidance are waste minimization and recycling & reuse of materials, denoting that recycling is the next best action after avoidance. Waste minimization is the reduction of waste before it reaches the MSW stream. Industries and manufacturers can minimize the amount of wastes during production but changing the process or by recirculating the appropriate waste component into appropriate portions of the process. An example in a residence is when a family consciously changes their purchasing and use behavior to decrease the amount of waste that is collected from their house.
The red line under recycling & reuse of materials divides the triangle between the top (recycling) and the bottom (waste disposal). WtE & Co-Processing is the most desirable of the waste disposal methods because the waste can be transformed into energy. In order, after WtE, from desirable to undesirable are incineration, chemical-physical pre-treatment, landfilling and unmanaged waste; the only thing worse than landfilling is not doing anything to treat the waste.
Avoidance includes activities such as good consumer goods choices or giving the item a new purpose or owner after the item has met the end-of-life use for the original purchaser, or minimized the waste. A new use can be found by donating the item to an appropriate organization or for something like a piece of clothing, the material can be reused. In order to minimize a substance or item at end-of-usefulness recycled materials can be divided from the main waste stream. Waste minimization is the activity of recycling plastic water sachets when they are empty or recycling the aluminum can or glass bottle after the drink inside has been consumed. The Central Europe Repair & Re-use Centres and Networks (2011) suggest the following actions for recycling “checking, cleaning, repairing, refurbishing, whole items or spare parts.” (3). In Saudi Arabia a large amount of recovery of reusable materials and recycling is accomplished informally by scavengers who pick up materials and items with value from the waste stream.
Municipal Solid Waste
The World Bank defines MSW as non-hazardous waste. According to the U.S. EPA universal waste is waste that ranges from low to high risk to human safety and health and risks to the environment. In order to take into account the degree of risk of commercial MSW and household MSW needs to be regulated (EPA 2005). Commercial and household wastes containing cadmium, mercury, copper, lead and any potentially toxic compounds need to be regulated so that only acceptable concentrations of potentially toxic ingredients are in a waste stream (EPA 2005). An example is in the state of California that legislates the concentrations of metal allowable in the waste stream (CDTSC 2012).
MSW is commonly called the garbage, rubbish or refuse generated many sources in a neighborhood and the larger urban community. Sources include not only residential households of all types, but also restaurants, small businesses, other commercial enterprises and medical facilities. When the waste from medical facilities is handled appropriately, the toxic or biologically dangerous materials must be kept separately from the other waste components. Toxic substances need to be divided from non-toxic substances in order to ensure public safety and also to enhance waste treatment. Laisis (2004) explains that hazardous waste like radiation and toxic chemical substances can kill the microbes that are responsible for degrading solid wastes in anaerobic (without oxygen) and aerobic (oxygen) conditions. Other sources are from garbage and litter that has been left at the edges of roads, at informal dumpsites in the dessert and other inappropriate areas where people throw out unwanted items.
Recovery and reclamation are two types of recycling. Energy recovery describes the process in WtE when thermal or electrical energy is recovered. Thermal energy is input back into the process, whereas electrical energy is produced by recovering gasses from landfills. In a waste plant a thermal treatment is the use of high to very high temperatures to decompose waste. Current MSW thermal treatments include combustion, incineration, gasification and pyrolysis.
Reclamation occurs when “a substantial portion of the total produce is reused in a manner consistent with its original purpose” (U.S. EPA 2014). Reclaimed items are recovered in order to be used as the item was originally intended (U.S. EPA 2014). An example is when scavengers recover items that have been tossed into the waste stream but are still in good condition. The original owner considers the item waste, but to someone else a piece of clothing, furniture, bucket or other article is usable.
Anaerobic and aerobic digestion
Anaerobic digestion is the use of microbes that degrade the rotten (putrescible) fraction of the waste with no oxygen available (World Bank 2014). The conditions at the bottom of a landfill, dump, or unturned compost pile are without air. Aerobic digestion is commonly part of home composting. The organic, biodegradable food wastes are decomposed by mixing and tossing the waste so that oxygen is made available for the degrading microbes (World Bank 2014). Aerobic and anaerobic microbes are different. The aerobic degrading strategy is used in neighborhoods because the degradation is faster. Also if the wastes are mixed thoroughly at regular intervals no odors are produced.
The factors influencing the rate of degradation are the conditions (aerobic or anaerobic), the humidity (moisture content), and temperature. Organic materials that degrade slowly or with composting produce a good soil reconditioner that improves top soil (Hickman et al., 2005: Miller 2005).
A major division of MSW is between combustibles and non-combustibles.
The classes are further divided by into controlled and uncontrolled. Aderogba and Afelumo (2012) note the four main categories of controlled waste.
Whereas, uncontrolled wastes are divided as follows.
- Inert materials (non-biodegradable materials such as aluminum)
- Hazardous wastes
- Municipal Solid Wastes
- MSW Management (MSWM)
Historically, generations have managed solid wastes by burning them, in other words, by incineration (Miller 1990; Smolen 1992). Mining pits left by miners after all the valuable metals and materials and quarries emptied of gravel, limestone and other materials left holes in the land. So the empty cavities left by unused mines and quarries were used as dumping sites. Smollen (1992) describes the ready-made dumps as “disused quarries, mining voids or burrow pits.” Municipalities and private companies are responsible for the collection, transport, street sweeping, litter pick-up done by-hand, recycling, and recovery and sorting of wastes.
The agencies responsible for the wastes must cooperate in order to properly manage all the necessary activities. Other stakeholders include the public, the local government, and regional and state agencies that set standards and enforce regulations. The small businesses that purchase recycled or recovered items, materials and metals are stakeholders. Management of waste requires covering the costs and so funding sources must be found or cost must be cut in order to stay with budget limitations. Cutting costs can occur with well-managed operations that are adaptable to constant improvement and transforming waste into energy.
Multiple manual handling of wastes is inefficient. The World Bank (2014) defines manual handling as the separation by hand of MSW that can be composted or recycled. A loads of waste can have many different handlers but starts when the generator sets their waste out for collection and divides their waste into separate recyclable waste streams. The waste is then picked up by the hauler and tossed into the garbage truck or other vehicle. Some municipal waste agencies use transfer stations as a location for the truck to be unloaded so sorting can take place.
The transfer station is a way station where collection and hauling vehicles can split the load so that it can be transferred to other landfills or disposal sites. Transfer stations are often used as a materials recovery facility (MRF) where sorting for recycling and recovery. Mixed municipal solid wastes can be sorted into a specific fraction. In Nigeria empty plastic water sachets are sorted and nylon cord is produced at the transfer station (LAWMA 2012).
Waste is generally sorted into categories of plastic, metals, and cardboard in northern Africa (LAWMA 2012). The waste that has no further use is then carried to the final step for further processing such as in a landfill or for incineration. The advantage to manual handling is that jobs are created and the leftover waste after sorting is reduced. A tipping truck is used in some countries for collection, driven directly to the landfill when full and dumped into the landfill or at the next processing step without manual handling. The World Bank (2014) reports that developed countries usually have no more than single manual handling, whereas other non-industrial or developing countries have more.
The general movement through society or the life cycle of an item starts with raw materials (A) and ends with the least amount of waste possible that needs to be disposed (B). (See 2-18) Raw materials are used for manufacturing consumer goods (industrial production) ; after production the industrial scraps can be recycled back into the production process with the rest being released into the industrial waste stream. When an item is purchased it reaches the domestic use portion of the life cycle. At the end of domestic use the material or item can be recovered, recycled, reused or it may enter the waste stream. Waste management starts at the end of use for industrial or domestic use materials. The waste management design determines the flow to reuse, recovery, recycling or to energy production before the final disposal of materials that are left.
A Life Cycle Assessment (LCA) has been standardized by the regulation of International Standards Organization (ISO) 14040. The purpose of an LCA is to increase the efficient use of resources and decrease any liabilities by assessing the effects of the wastes on the environment through the life cycle until the end of usefulness (EPA 2014). Life cycle assessments are performed on products, a products function or a process. The assessments are complex so computer models and LCA calculators are used for the following reasons.
- Recognize the environmental loads
- Quantify the impact of the environmental loads
- Evaluate the potential impact
- Enhance decision-making by identifying the degree of environmental impact of the various factors in the life cycle process
An example is carbon dioxide, a gas that increases the global warming phenomena. The environmental load is the concentration of carbon dioxide emitted into the atmosphere. and then converting the concentration into carbon equivalents. The potential impacts are diverse, but in the example using CO2, the appropriate potential is the Global Warming Potential. A total of ten impact categories are considered for a full life cycle assessment. (see fig. 2-3) In order to compare the impact categories equivalents (eq.) are calculated. The following impact categories are calculated to access the life cycle of materials and processes.
Abiotic depletion assesses whether or not the raw material used as a resource is non-renewable or renewable.
- Global warming potential
- Ozone layer depletion
- Human toxicity
- Fresh water aquatic eco-toxicity
- Marine aquatic eco-toxicity
- Terrestrial Toxicity
- Photochemical oxidation
- Solid Waste Management Techniques
- Landfills and Energy Recovery
An area of land designated by a municipality to contain waste is called a landfill. The proper siting of landfills is very important, but without the regulations necessary a culture of waste management many landfills are simply holes filled with garbage or dumps on the surface in Saudi Arabia. Regulated landfills need to study locations in order to find the best place that is not too far from waste generation sites but far enough from residential areas to prevent problems. Problems can arise due to the increased traffic, litter blowing off the top of the landfill, the presence of scavengers, odors, or water pollution (Aderogba & Afelumo 2012). The criterion that needs to be considered for the siting of a landfill is listed below.
- Value of the land
- Collections trucks, tipping trucks need easy access and room to dump the waste and when necessary transfer the waste
- A landfill needs a good place nearby for a transfer station
- Regulations and permitting requirements need to be met
- Costs including permitting fees need to be calculated
- What is the neighborhood type: residential, commercial, farming or industrial
- Are natural resources in the area such as brooks, creeks, flood plain, aquifer depth, rivers, and agricultural or gardening soils
Residential waste is household garbage or refuse that is generated on a daily basis and includes food wastes, clothes, tops, empty bottles and other unwanted items. A residence can be a single-family home, a multiple-family apartment building or housing that is designed for any number of residents.
Controlled landfills used for WtE are lined to collect the methane and other bio-gases for conversion to thermal energy and then to electricity (Moore 2002). Lining a landfill also protects the surrounding soil, nearby water bodies, and groundwater from contamination (World Bank 2014). Landfills are divided into cells. Cells are the compartments that are filled according to a plan with the MSW. Waste is dumped from a tipping truck into the cells that are open for use. Waste is dumped from a tipping truck into the cells that are open for use. Cells are used because each cell is easier to control for sanitation purposes and to avoid pest and odor problems (Moore 2002). The waste is then compacted so as much waste as possible can be put into each cell. At the end of each disposal for the day, no matter how full the cell, the waste in the cell is covered with a layer of soil.
Well managed landfills are lined with compacted clay or plastic linings to discourage vermin from entering the garbage and to prevent landfill leachate from entering the surrounding environment of soil and water. (See fig. 2-6) On the left hand side of figure 2-6, note the groundwater test well that is in place so the groundwater can be monitored. Leachate is the liquid, sometimes called wastewater that is a by-product of garbage degradation; the leachate trickles or percolates through the land filled waste (World 2014). No leachate should reach the groundwater. Gases created in the landfill from the degrading of the waste are collected by a pipe distribution system that uses gravity to pull leachate to the bottom. (See fig. 2-6) The pipes have tiny perforations to allow seepage from the anaerobic degradation. Methane gas is the gas created in the largest amount, but all the landfill gasses are collected. The collected gasses may be burned off by a flare or distributed to a WtE facility near the landfill.
Figure 2-7 depicts a large landfill divided into layers of cells and containing a sophisticated gas extraction process. The gasses that are generated in large amounts are methane (CH4) as mentioned above and in smaller amounts carbon dioxide (CO2) and hydrogen sulphide (H2S) (World 2014). Trace amounts of volatile organic carbons (VOCs) but must be controlled because of the risk to the environment from toxic VOCs (EPA 2014). The leachate collects CH4, CO2, and VOCs as the gasses travel by gravity through the trash towards the bottom of the landfill. CH4 is worse than CO2 to the environment to the atmosphere because it stays in the atmosphere longer, and trapping heat for sunrays close to the surface of the earth (EPA 2014). Methane is a flammable gas and once CH4 enters the atmosphere, it can stay in the atmosphere for 12 years. Life Cycle Assessments (LCA) assess the effects of substances, materials and emissions in the environment using the measurement of potential impacts.
Methane is measured for Global Warming Potential (GWP). For example, the GWP for more than 100years for methane is 21 compared to carbon dioxide with a GWP of 1. CO2 is a part of the earth’s essential carbon cycle (EPA 2014). Methane traps radiation more efficiently than carbon dioxide (EPA 2014). The effect in a greenhouse is similar to when solar radiation is trapped close to the earth’s surface causing the greenhouse or atmospheric effect (EPA 2014). In other words, methane and carbon dioxide are both greenhouse gasses, but the negative impact on the atmosphere from methane is twenty times higher than the negative impact by carbon dioxide during a 100 year period (EPA 2014).
Monitoring of the processes in the landfill takes place by using monitoring wells to record temperature and other relevant data. In the landfill a system of gas extraction pipes and wells collects gasses from the layered cells. The extracted gases are distributed by pipes to the landfill gas-to-electricity LFTGE plant or to continue the process until electricity has been produced. Another modification is to collect the leachate in a plant to be further processed. Leachate treatment is required because carbon from the carbon dioxide produced inside a landfill must be collected and treated before emission into the environment (EPA 2014). Decreasing the amount of leachate that needs to be disposed lessens the problems on the environment. One strategy is to recycle the leachate through the landfill, because the additional moisture increases the rate of degradation (EPA 2014). Recirculation of the leachate through the waste also increase the quantity of gasses formed for energy recovery (EPA 2014). Another strategy that is useful is to combine leachate with irrigation water to irrigate land near the landfill (EPA 2014). And a third strategy is to treat leachate with wastewater from other sources using biological and physical-chemical processes.
The major problem with landfills is that land is a premium asset and people need the land for other uses. Other problems arise when pests like vermin and birds eat the garbage in the landfill. If the landfill is poorly constructed or has no liner the risk to the soil and water in the vicinity is high. The other major problem with landfills is that so much waste is being generated; landfills are eventually filled up and closed. On the other hand landfills are a useful management method to use when transitioning to more sophisticated types of MSWM. The initial creation of a landfill is expensive but the leachate gasses can be used for thermal or electrical energy recovery.
Energy Recovery adds value to the leachate collected in the landfill. The definition of recovery is adding value to waste before the final disposal (EPA 2014). Recycling in terms of energy recovery incorporates the collection and recycling of the leachate gassed and the conversion of the gasses to thermal or electrical energy (EPA 2014). That means extending the value of the wastes even though the wastes are already in the landfill.
Life cycle assessment
Life Cycle Assessment is an important part of the systems engineering process. The life cycle of a material from the raw material until disposal requires the an integrated engineering systems process from beginning to end; from the raw material to disposal. The first step of the process is careful planning by analyzing the requirements to reach the goal of recycling in Saudi Arabia in order to develop a realistic preliminary design. The next step in the cycle is to gather the opinions of the stakeholders. The design should be able to withstand a critical review by the residents; therefore surveys using questionnaires and interviews during the planning can help enormously.
Installation, integration, testing and acceptance constitute the third step. The time taken planning and reviewing the process will be tested at this step; demonstrating the need to prepare well from the very beginning. The fourth step in a system engineering process is to continue to capture and incorporate customer requirements into all phases of the process. The stakeholders will have changing needs as prices change for recycled materials, national regulations and standards are put into law and residents start incorporating recycling into their daily lives. The interesting factor about the systems engineering approach is that the cycle never ends. Improvements can always be identified and implemented.
The five main reasons solid waste management has developed over the years is due to the following principal factors (Marshall and Farahbaksh, 2013).
- Public health
- Scarcity of resources and waste value
- Climate change
- Awareness and Participation of the Public
Driver 1 is public health, factor influenced by epidemic diseases. (See Fig. 2-11) In turn public health initiates cyclical actions by impacting institutional change which causes municipal solid waste collection and removal from urban areas. Driver 1 public health impacts the need for public health regulations and standards so legislation is passed. The legislation calls for the cleaning dumps and litter causing poor sanitary conditions. Without the legislation epidemics and illnesses occur causing a negative impact on public health and once again, public influence on the municipality so the wastes are removed and pressure on regulatory and legislative bodies for sanitary standards.
Driver 2 is the green environmental movement on political and public agendas. Wilson (2007) diagrams the connection between city collection and removal of solid waste to the focus on final waste disposal methods which leads to driver 2. Public concerns and awareness about waste collection, removal and disposal are intensified by environmental groups who educate the public on options available. When the public exerts enough pressure the regulations are legislated and regulatory agencies are established. The new rules encourage (or insist upon) recycling and reuse behaviors by waste generators.
Lean Six Sigma
Lean Six Sigma management strategy grew out of the complimentary strategies of lean management and Six Sigma. The strategy is a promising way for Saudi Arabia to make recycling of municipal solid waste a priority for the whole country of Saudi Arabia. Input from all stakeholders is an important part of the management technique; just as the stakeholders must be actively involved in creating a successful recycling programme in Saudi Arabia. The strategy is particularly attractive because it is founded on efficiently reaching the goals set. The strategy offers a plan for thinking about managing projects as well as tools to make the project flow more efficiently. Importantly the tools enhance the control of the project manager. Establishing a recycling attitude as well as the recycling activity in Saudi Arabia is a complex issue. The tools are helpful for controlling the complexity without overlooking important details.
The five phases of a project are essentially the same for every project: define the mission and initiate the project, establish the plan and share the plan, execute the plan, manage results at benchmarks and either close the project or renew the project to meet new goals. James (2006) highlights the need for teamwork. Firstly, the first step is to Initiate and Define. (See fig. ) Defining the mission and the goals are extremely important so that everyone is working towards the same goal. The mission and goals need to be reviewed regularly to keep everyone on track. The cause and effect of taking different actions need to be evaluated, Pareto diagrams enhance the ability to rate the problems and decided where to start. Planning may take two or more months, but establishing a realistic plan is essential to success. Value stream mapping is useful, especially in a MSW project where value is placed on waste. Developing a fishbone diagram of tasks or the use of a Gantt scheduling critical path can help enormously in the planning and in the execution of a project. Executing the project requires hard work and focus. Managing the results does not happen only at the end of a project. Managing the results must be done at every benchmark. Lean Six Sigma tools for managing results include the balanced scorecard technique, visual systems and software like the Gantt critical path. Statistical assessment of results is carried about by using ANOVA software that is available with Excel or in software packages on its own. In a complex project like planning recycling in the large urban areas of Saudi Arabia will require team work to proofread the results for errors. A project like this is never going to end per se, but at the end of important phases of the project is a good time to make any improvements needed in the strategy and set new priorities. Not every technique listed under the five phases in the Technical Lean and Six Sigma figure are necessary in all projects. But, the five steps are essential to develop and manage a successful project.
Lean Six Sigma also integrates Social Lean and Six Sigma Tools along with the technical techniques discussed above. The five stages of the social part of the strategy are to (a) initiate and define, (b) plan, (c) execute, (d) manage results and (e) close and renew. The five phases are the same as the technical process but accomplishing the phases on the social level requires different strategies.
Good communication and transparency are the most important values of the project to model and to encourage. The social strategies recognize that at the very start of a project many people will be resistant to change. Resistance to change is normal so a project manager must be ready to make a case for the reasons that change is needed. Brainstorming with other stakeholders and team members often adds insights that improve the execution of the project. Planning (the second phase) requires brainstorming and teambuilding. At the planning stage survey research can help to understand the recycling behaviors that residents are familiar with or that they are willing to use. Questionnaires and interviews can also enhance understanding between different levels of government that must be involved in the recycling project. The agencies, municipalities and the legislatures need to be brought onboard. Public policy for recycling is an essential part of making the strategy successful. Regulations, permits and fees for different phases of the recycling process will need to be established. The social phase of execution requires regularly scheduled status meetings, instructions presented as “do-its” and monitor organizational effects. The flow of necessary resources needs to be timely, so keeping in touch with leadership in government agencies will help ensure help when necessary. Managing the results can be handled with management strategies like the balanced scorecard which should be used at regular intervals. Managing the complexities of the process will be extremely challenging. For the end of the project or the renewal as it will in this case, having a celebration and sharing lessons learned can be done at the same time. After reaching benchmarks and phase goals, rewards and team recognitions will keep the atmosphere of the project. The project will bring times of stress between team members and the rest of the stakeholders, but a strong commitment to open and constant communication will help pass through difficult periods.
Chapter 2 reviewed primary sources in order to report data about recycling, waste composition, and waste generated as well as other pertinent data necessary for the complexities of engineering systems process. The above examples show that Saudi Arabia is not the only country facing major problems with MSW. Saudi Arabia is not alone in needing to develop high quality, workable and efficient recycling strategies. On the other hand, Saudi Arabia can learn from the experience of Japan and other countries when designing a highly efficient national recycling plan. Recycling strategies must be designed that will suit the municipalities in the country that are rapidly growing. Saudi Arabia can learn that developing a culture where recycling materials is appreciated must be developed. The U.S. requires bottles and packaging and other items made with plastics to have the code number on the items Developed countries vary in the priority placed on recycling and waste reduction but Saudi Arabia has the resources necessary to use systems engineering process approach while at the same time incorporating management strategies from the Lean Six Sigma management plan.
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