Environmental gains in the collection of packaging waste obtained in Uskudar district by changing the collection type

ABSTRACT

The collection of packaging wastes separately from domestic wastes is a legal requirement and has become a necessity due to the need for raw materials today. Due to the legislative requirements, disruptions in practice constitute an obstacle to create a successful waste management policy. The subject of this study is to provide a system that will help the administrators of the district municipalities who want to collect the packaging wastes with their own means. In Uskudar municipality defined as a pilot area, environmental gains have been achieved by collecting packaging wastes separately from domestic wastes in two different days. The results of the collection of packaging wastes from households separately from domestic wastes were analyzed by separate collection days of district municipalities. Waste characterization studies are carried out, and the evaluation is presented. In this study, it was determined that the environmental gains obtained by changing only the packaging waste collection days yielded important results. The classical collection model, Uskudar Model and the effect of not collecting packaging wastes on ecosystem and people were examined by life cycle analysis.

Implications: The importance of the environmental contribution of the proper packaging waste collection system. Environmental contributions provided by recycling only by changing the collection system. Revealing the environmental contributions of the packaging waste collection system through life cycle analysis.

Aim of the study

In this study, the economic and environmental benefits obtained by changing only the collection method within the scope of recycling activities were made by Life Cycle Analysis (LCA). In the first scenario, it is assumed that the amount of packaging waste collected with the classical collection model is reevaluated, in the second scenario, the amount of packaging waste collected with the Uskudar Model and its reevaluation, and in the third scenario the collected packaging waste amount is buried in the landfill. It has been observed that if the Uskudar Model, which is offered as an alternative to the classical available collection method defined as separate collection of packaging wastes at the source, is preferred, negative environmental impacts are reduced. The basis of the collection system defined as the Uskudar model is that two days are selected for packaging waste, and organic waste is collected at different times. In these two days, organic wastes were not collected, only the collection of packaging wastes and the environmental and economic gains were quantified with the LCA analysis, and the benefit analysis was presented.

Literature

With the rapidly developing industrialization and increasing world population, natural resources are being depleted, and every year, the raw material defined as waste having millions of dollars worth is buried in landfills (European Commission, JRC report 2019). The wastes and their types created by the increase in consumption have reached a level that threatens the environment and human health due to both the amount and harmful contents (Di Maria, Mastrantonio, and Uccelli 2021). Wastes; it is formed as a result of domestic, commercial, and industrial functions, while some of these wastes can be recycled, some of them are out of the recycling cycle. Integrated waste management is defined as the process that extends to the formation, use of the product, the end of its useful life, and then to its final disposal, and this situation makes significant contributions to the environment and humanity (Fan et al. 2021; Viotti et al. 2020). Implementation of effective waste management system is not only responsibilities of private businesses but also with regulators and policymakers (Sun et al. 2020). Because of being recyclable, easy to handle and its economic value, the packaging wastes consisting of different materials such as papers, paperboards, plastics, aluminum, steel cans, and glass/jars are most favorable among the other waste sorts. In addition to these benefits, also with recycling; prolonging the life of the storage areas by reducing the amount of waste that will go to landfills, protecting natural resources or reducing the consumption rate, reducing the demand for raw materials, reducing energy consumption in production processes, protecting the ecosystem and wildlife, reducing pollution, especially reducing carbon emissions, waste collection and disposal costs reduction is achieved. In this respect, it is very important to collect household waste and packaging waste separately or to develop a useful method in this regard. Because domestic wastes generally consist mainly of biodegradable organic wastes and have a high water content. Since packaging wastes contain recyclable wastes, the useful use of these wastes should not be spoiled by mixing them with domestic wastes. In addition, the recyclable efficiency of packaging waste mixed with household wastes decreases. The preference and use of such packaging materials depend on the types of products, cost, and packing purpose (Tallentire and Steubing 2020; Yong-Chul et al. 2020). Packaging waste is defined as any packaging and packaging material that meets the definition of waste. Packaging wastes are divided into six groups according to their types as paper/cardboard, plastic, metal, glass, composite, and wood.

The emergence of an economical system that reduces the demand for raw materials and observes resource efficiency by considering the needs of future generations in the world has become necessary (Dagiliene et al. 2021). This new production system is expressed as Circular Economy. Circular Economy is defined as the economical approach in which any product, material, and/or resources are kept in the system as long as possible, and the amount of waste is the lowest. As seen in Figure 1, the circular economy is a closed cycle in itself (Velenturf and Purnell 2021). In the circular economy, only glass waste has an endless cycle. Other than that, metal, paper, and plastics are not included in the cycle with the same efficiency. Therefore, even in the circular economy approach, a small amount of waste may result from these materials. However, this situation is too low and controllable to be compared with the linear economy approach. While the circular economy involves the inclusion of the wastes generated as a result of consumption into the production process, yet in the linear economy, the process is generally processed with the use of raw materials in the production stages, and after waste generation, these wastes are disposed of without being adequately evaluated (Michelini et al. 2017). The circular economy is nowadays expressed to be one of the most favorable sustainable development concepts on recycling system leading to furthering environmental, economic, and social goals (Geissdoerfer et al. 2017). Although there are statistical data on many recycling studies, their equivalents at the cyclical economic level are not yet fully revealed (Millette, Williams, and Hull 2019).

Figure 1. (a) Linear economy approach (b) Circular economy.

The European Union requests the following from the member states under the Waste Framework Directive in 2020.

• Reuse and recycling of recyclable wastes in municipal wastes should be increased to at least 50%.

• It should be ensured that non-hazardous construction wastes are reused, recycled, and recovered to at least 70%.

• Also under the landfill directive, it is aimed to reduce the amount of biodegradable wastes going to landfill to 35% (EU Landfill Directive 1999/31/EC 1999).

• And under the Packaging and Packaging Waste Directive; it is aimed to recycle at least 60% of packaging wastes by weight or to incinerate them in waste incinerators with energy recovery (EU Directive 94/62/EC 1994).

• EU target for recycling 75% of packaging waste by 2030 (Ribić, Voća, and Ilakovac 2017).

Especially, in terms of plastic recovery, increasing plastic waste recycling defines as a milestone of European environmental policy to reduce environmental impacts and dependency on foreign resources (Antonopoulos e al. 2021). It is clear that if current practices for plastic usage continue, it is estimated that by 2050, there will be 12,000 Mt of plastic waste in landfills or in the natural environment (Geyer, Jambeck, and Law 2017). This huge value represents both a loss of valuable material and also poses a significant risk to the environment and wildlife (Barchiesi et al. 2021; Davidson, Furlong, and McManus 2021; Klemeš et al. 2020).

The Circular Economy Strategy at the EU scale: it is stated that by reducing the consumption of raw materials by 20% in production, it will bring an annual economic gain of 600 billion Euros. With this circular economy, 500 million tons of carbon emission gains are expected to be achieved in 2035 and besides this, 750,000 people are expected to be employed (European Commission Report 2014). Detailed targets have been set for the recycling of packaging waste in EU countries, and these targets are included in Table 1.

Table 1. New targets for packaging waste recycling in Europe (European Parliament and Council Directive 94/62/EC 1994)

Type of Waste	Between 2025– 2030 years	After 2030 year
All of packages	%65	%70
Plastic	%50	%55
Wooden	%25	%30
Ferrous metals	%70	%80
Aluminum	%50	%60
Glass	%70	%75
Paper and cardboard	%75	%85

Materials and methods

Uskudar model for management of packaging wastes

In general only 90% of household waste, which is produced about 31.6 million tons annually is landfilled and disposed of in Turkey. According to data for 2020, Istanbul’s population is 15,519,267, which corresponds to 18.4% of Turkey’s total population. The average daily solid waste amount per person is 1.30 kg for Istanbul (Turkish Statistical Institute 2017). According to the data of 2017 in Turkey it was achieved a 53% recycling of packaging waste for the year of 2017 (Bulletin of Ministry of Environment And Urbanization of the Republic of Turkey 2017). The recycling target by 2020 for Turkey was determined to be 60% (Packaging Waste Control Regulation in Turkey 2017).

Uskudar is located on the Anatolian side of Istanbul. The area of the district is 36 square kilometers. There are 33 neighborhoods, 146 avenues, and 2395 streets in Uskudar district. The population of Uskudar district has been determined as 582,666 according to the last census conducted in 2020 (Turkish Statistical Institute 2017). Considering 2016, one year after the Uskudar model implementation, 3.850.712 tons of packaging materials were produced in Turkey and 2,226,273 tons of this amount were recycled, which means that 58% of packaging waste was recycled. On the other hand, an average of 19,500 tons of domestic waste is generated in Istanbul per day, 12,500 tons of which is on the European side and 7,000 tons on the Asian side. As packaging waste among these total wastes, the amount of packaging waste collected by years throughout Istanbul is given in Figure 2.

Figure 2. Collected packaging waste in Istanbul, tons per year.

The comparison of the change in the amount of packaging waste collection before and after the Üskudar Model is given in Table 2.

Table 2. Packaging waste change before and after the Uskudar model

Years	Paper tons/year	Cardboard tons/year	Plastic tons/year	PET tons/year	HDPE ton/year	Metal tons/year	Other tons/year	Glass tons/year
2012	479.912	1.919.648	159.971	9.598	213.294	53.324	622.108	1,052,658
2013	522.878	2.091.513	174.293	10.458	232.390	7.843	677.805	1,408,932
2014	546.488	2.185.952	182.163	10.930	32.789	60.721	708.411	1,558,924
Average	516.426	2.065.704	172.142	10.329	159.491	40.629	669.441	1,340,171
	Uskudar Model application (after 2015)
2016	1.719.145	6.876.579	573.048	34.383	764.064	191.016	2.228.521	686.906
2017	2.049.221	8.196.884	683.074	40.984	910.765	30.738	2.656.398	718.374
2018	1.942.514	7.770.055	647.505	38.850	116.551	215.835	2.518.073	821.470
Average	1.903.626	7.614.506	634.542	38.073	597.127	145.863	2.467.664	742.250

Domestic wastes mainly organics and packaging wastes are collected daily at the same time in almost every district of Istanbul Province, which is defined as classical collection system (CCS). On the contrary of this collection system, Tuesday and Friday are determined as only packaging waste collection days in Uskudar Municipality, which is called the Uskudar Model. In these two days, citizens leave only packaging wastes out of the door and domestic wastes are not taken out in these two days. With this new collection system, an increase of 278% has been achieved in the amount of packaging waste collected in the district. In Uskudar, while the average monthly amount of packaging waste is 430 tons according to the CCS, this rate has increased to 1200 tons of packaging waste in Uskudar Model. Because of collecting glass packaging waste in separate boxes in Uskudar in the available status, according to the new collection model it is seen that there is a 50% reduction in the amount of glass in the waste characterization in packaging waste.

Approximately 92.8% of the average daily 40 tons of recyclable waste generated in Uskudar is packaging waste, and the composition of this waste is given in Figure 3.

Figure 3. Packaging waste characterization collected on Tuesdays and Fridays.

Life cycle analysis of Uskudar model for recycling

Life Cycle Analysis (LCA) is a support tool for analytical decisions and is a method that is used and continuously developed in decision-making processes (Khasreen, Banfill, and Menzies 2009). LCA is a holistic system. All kinds of environmental impacts that may arise in all processes of the product or service being evaluated from cradle to grave are put forward cumulatively. The LCA methodology was used for the evaluation of the environmental impacts associated with the waste management operations (collection, sorting, pre-treatment, recycling, incineration, and landfilling) (Ferreira et al. 2014; Jeswani et al. 2021; Simon, Amor, and Földényi 2016). LCA stands before us as a system that not only reveals environmental impacts but also a model that reveals economic and social gains (Ferrão et al. 2014). In the LCA Methodology, an inventory of environmental emissions is made by arising with the energy, water, and other raw materials and natural resources used.

As can be seen from Figure 4, LCA methodology consists of four separate analytical steps. These are defining the purpose and scope, establishing the life cycle inventory, assessing the impact, and finally interpreting the results (Khasreen, Banfill, and Menzies 2009). According to LCA methodology based on the ISO 14040 standard, the chronological order of LCA methodology can be described by four interrelated phases, as shown in Figure 4. These are purpose and scopes (goal and scope definition), inventory analysis, impact assessment, and interpretation, respectively (ISO 14040 Standard). The double sided arrows in Figure 4 imply that the phases are continuously interrelated. If there are some unsatisfactory and missing parts in one phase, which will affect the intended application of the whole study, then the other phases must be revised and improved. As a result of the qualitative and quantitative determination of the relations of these four concepts with each other, only the LCA method can be carried out properly (Curran 2006).

Figure 4. LCA Methodology.

In this study, SimaPro 8.2.3.0 package program and Ecoinvent 3 library in this program and IMPACT 2002+ method were used for LCA calculations. SimaPro model ensures the environmental performance of products and services is evaluated.

IMPACT 2002+ was initially developed by the Swiss Federal Institute of Technology (Figure 5). The methodology is used to link 14 midpoint categories to 4 damage categories (i.e., endpoint categories). Midpoint categories are used for classical impact assessment methods, which have restrictions on quantitative modeling.

Figure 5. Overall scheme of IMPACT 2002+ (Jolliet et al. 2003).

They are also used to limit uncertainties, which occurred due to the cause-effect chain. Endpoint categories are usually used by damage-oriented methods, and the calculations sometimes have a high degree of uncertainty. While midpoint categories express some points located between Life Cycle Inventory (LCI) results and the endpoints, damage categories represent a quality change on certain issues. It was indicated that IMPACT 2002+ provides feasible answers for these questions:

• How to adopt conventional risk assessment methods to calculate cumulative chronic toxicological risks and potential impacts?

• How to account in a generic but accurate way for nonlinear functions?

• How to structure fate, exposure, and effect of chemicals in a consistent way? (Jolliet et al. 2003).

Several midpoint categories have effects on different damage categories. Human health damage category is the sum of human toxicity, respiratory effects, ionizing radiation, ozone layer depletion, and photochemical oxidation. The uncertainties for fate, exposure, and effect are low for resources, medium for human health, and high for both ecosystem quality and climate change (Humbert et al. 2012).

In LCA process, there are four damage categories, and they are expressed with a specific unit. These are Human Health, Ecosystem Quality, Climate Change, and Resources in LCA process. Human health category includes human toxicity (carcinogenic and non-carcinogenic effects), respiratory effects (inorganics and organics), ionizing radiation, and ozone layer depletion and is expressed as DALY unit (disability-adjusted life years) (Jolliet et al. 2003). DALY is widely used for public health to measure the disease burden as a unit. DALY is also defined as the loss of healthy life lost from human life (Gronlund et al. 2015). DALY as a method of measurement normally assumes that each person potentially lives in one year of optimum health. But due to different environmental reasons, people can lose these healthy years of life. Therefore, it was developed as a measure of the loss of healthy life years (Devleesschauwer et al. 2014). For example, a product with a human health score of two DALYs represents 2 years of life lost over the total population. Another unit used in LCA process is PDF×m²×year (Potentially Disappeared Fraction) to express Ecosystem quality parameter. The midpoint categories of this parameter are terrestrial acidification, terrestrial nitrification, and land occupation and their impact. Ecosystem quality is measured by PDF×m²×year unit, which corresponds to Potentially Disappeared Fraction of species over a certain amount of area during a certain amount of year. PDF×m²×year represents the fraction of species disappeared on 1 m² of earth surface during 1 year. For instance, a product having an ecosystem quality score of 0.2 PDF×m²×year implies the loss of 20% species on 1 m² of earth surface during 1 year. In LCA process, another damage category is climate change, and it is represented as kg.CO₂(eq) unit. Kilogram equivalent of a reference substance expresses the amount of a reference substance that equals the impact of the considered pollutant. In this study, CO₂ is taken into consideration as the pollutant reference parameter. For example, a product with a climate change score of 27.75 kg CO₂(eq) means 27.75 times higher than CO₂. Another damage category defined in LCA process is resources, and its unit is given as MJ primary. It measures the amount of energy extracted or needed to extract the resource (Humbert et al. 2012). The two midpoint categories, mineral extraction and nonrenewable energy consumption, contribute to the final impact in the resources category. Resources category is based on the assumption that a certain extraction leads to an additional energy requirement for further mining of this resource in the future, caused by lower resource concentrations or other unfavorable characteristics of the remaining reserves.

Packaging waste management scenarios

The Uskudar Model, which is the subject of this article, was launched in 2015 and is a first not only in Istanbul but also in Turkey in the management of packaging waste. The application of the method specified as the Uskudar model still continues with great success. In this study, the data considered as the Uskudar Model and the analysis process of these include the results of the field application between 2015 and 2019. In this study, these four-year data of the Uskudar Model are examined from environmental aspects for the first time, and the results are presented in detail with the LCA model, both qualitatively and quantitatively.

With the Uskudar Model, which introduces a different packaging waste management, it is seen that these wastes are again a part of production in a more efficient way in terms of circular economy. In addition, when the environmental gains obtained with this Uskudar Model and their beneficial effects are taken into account, a proven awareness will be revealed for both the other districts of Istanbul and Turkey in general.

In the characterization study of CCS, the amount of packaging wastes according to years in Uskudar was calculated as 50% iron, 30% aluminum, 20% other for metals and materials. In the LCA analysis, the possible mixed waste content among packaging wastes was defined as other, these wastes were not included in the calculation, and the program made the calculation by assuming that the wastes defined as other wastes were sent to the landfill.

In this study, the environmental impact efficiency of the Uskudar Model was examined by comparing the environmental impacts of the scenarios of managing packaging waste with the CCS and the Uskudar Model. The results were compared and evaluated by LCA analysis based on ISO 14044:2006 Standard (ISO Standard). Accordingly, three different scenarios have been developed in this study in order to perform the LCA analysis between the old system and the new system. These scenarios are:

Scenario 1 (S1)

In this study, Scenario 1 is defined as the transportation and processing of 430 tons/month of packaging waste to a collection, separation, and recycling facility at a distance of 17 km within the scope of the CCS. Characterization and quantities of wastes with this study were determined as paper: 43.036 tons/month, cardboard: 172.142 tons/month, plastic: 14.345 tons/month, PET (Polyethylene Terephthalate): 1.291 tons/month, metal: 4.782 tons/month, nylon (HDPE-HDPE): 19.127 tons/month, other packaging waste: 55.787 tons/month, glass packaging waste: 111.681 tons/month.

Scenario 2 (S2)

Scenario 2 is called as the Uskudar model, and accordingly, 1200 tons/month of packaging wastes collected separately on two days a week are processed in the collection, separation, and recycling facility at a distance of 17 km. The types and amounts of waste collected in this study are, respectively, paper: 158.636 tons/month, cardboard: 634.542 tons/month, plastic: 52.879 tons/month, PET (Polyethylene Terephthalate): 4.759 tons/month, metal: 17.626 tons/month, nylon (HDPE-HDPE): 70.505 tons/month, other packaging wastes: 205.639 tons/month, glass packaging wastes: 61.854 tons/month.

Scenario 3 (S3)

Scenario 3, on the other hand, is that 1200 tons/month of packaging wastes collected after the collection system based on the Uskudar model are not sent to the collection, separation, and recycling facilities, but directly landfilled with mixed household wastes in a sanitary landfill located at a distance of 41 km on the Anatolian side of Istanbul.

Visual presentation of these scenarios is as given in Figure 6, and the detailed wastes sorted according to all the scenarios are given in Table 3.

Table 3. Amounts of scenarios according to types of packaging waste

LCA	Packaging materials, tons/month
	Paper	Cardboard	Plastic	PET	Metal	HDPE	Other (mixed waste)	Glass
Scenario 1	43.036	172.142	14.345	1.291	4.782	19.127	55.787	111.681
Scenario 2	158.636	634.542	52.879	4.759	17.626	70.505	205.639	61.854
Scenario 3	158.636	634.542	52.879	4.759	17.626	70.505	205.639	61.854

Figure 6. Management scenarios implemented.

The LCA analysis ultimately gives damage categories in 14 impact categories and 4 main headings. These are human health, ecosystem quality, climate change, and resources.

In order to make the necessary calculations in the LCA model, first of all, waste types are defined separately in the system. For this, the waste groups that exist in the Ecoinvent 3 library were used (Moreno Ruiz et al. 2013). The Ecoinvent database is considered the most comprehensive corresponding to the European requirements for SimaPro software used in LCA analysis. In this study, LCA analysis was performed with the SimaPro 8.2.3.0 package program using the Ecoinvent 3 library database for the scenarios. According to this analysis, in order to compare both damage and impact categories, cardboard, paper, metal, glass, plastic, PET, and HDPE types were selected from the corresponding wastes in the Ecoinvent 3 library database. For example, when glass is mentioned in the Ecoinvent 3 database, this type of waste corresponds to all colored or colorless glass collected and recycled in the field. However, when metal is mentioned in the same database, the metal can be considered into sub-categories such as aluminum or steel. Since these types of waste were also collected as recyclable wastes in the field study, these types of waste were taken into account in the impact calculations. After creating these waste groups, the recycling process is defined separately. For the forklift used in the collection and separation facility, the LCA of the fuel calculation was made, and the environmental benefit, shipment, and electricity expenditures were calculated separately. A separate calculation was made for the other and mixed waste was sent to the landfill and the result of this was obtained. While calculating Scenario 1, the wastes separated by their types were calculated in two different categories as impact and damage.

The impact of iron, aluminum, glass, paper, PET, PE, plastic waste and other/mixed wastes going to the landfill were calculated separately for the impact categories in all the scenarios. Consequently, the impact categories were determined by adding the raw material consumption also to these calculations. After making calculations for each scenario, the scenarios were compared, and the environmental benefits of the Uskudar Model packaging waste collection method compared to the CCS were revealed. These impact categories for all three scenarios are given in Table 4.

Table 4. Comparison of scenarios by impact category

Impact category	Unit	Scenario 1	Scenario 2	Scenario 3
Carcinogens	kg C2H3Cl eq	−22,729.6708	−102,225.0812	1191.5234
Non-carcinogens	kg C2H3Cl eq	−17,372.0687	−75,773.0872	1727.5375
Respiratory inorganics	kg PM2.5 eq	−518.5299	−2643.6896	142.7579
Ionizing radiation	Bq C-14 eq	−1,613,861.3561	−7,800,168.2970	804,497.6037
Ozone layer depletion	kg CFC-11 eq	−0.0095	−0.0493	0.0062
Respiratory organics	kg C2H4 eq	−225.3572	−1126.1679	151.3413
Aquatic ecotoxicity	kg TEG water	−65,114,777.2875	−307,503,081.4644	66,911,296.7016
Terrestrial ecotoxicity	kg TEG soil	−23,099,172.8747	−108,434,257.0229	754,034.0766
Terrestrial acid/nutri	kg SO2 eq	−6630.7334	−31,962.3832	3284.4176
Land occupation	m^2org.arable	−235,008.2716	−1,101,859.4437	3956.0566
Aquatic acidification	kg SO2 eq	−1631.9543	−7606.6794	792.7188
Aquatic eutrophication	kg PO4 P-lim	−145.8876	−680.5481	50.1854
Global warming	kg CO2 eq	−199,557.9820	−883,203.5941	281,587.7621
Nonrenewable energy	MJ primary	−4,461,700.7668	−21,388,916.1991	1,552,906.9994
Mineral extraction	MJ surplus	7598.2422	36,084.0577	1157.2953

Results and discussion

Evaluation of LCA according to impact category

The inputs and outputs of each of the three scenarios were evaluated according to the impact and damage categories of LCA model. The impact and damage categories of LCA model are given in Table 4 for all the scenarios, respectively. In Table 4, all the scenarios are compared according to impact categories.

From Table 4, the scenarios of packaging waste management system in Uskudar District were analyzed and Scenario 3 gave the worst results for most of the impact evaluation parameters, in general. Human health damage category is given as DALY unit; it covers the effect categories of carcinogens, non-carcinogens, respiratory inorganics, ionizing radiation, and ozone layer depletion.

For all scenarios, additional calculations have been made according to the Damage Category, and these values are, respectively, Human health (DALY, Disability Adjusted Life Years) and Ecosystem Quality (PDF×m²×yr. PDF means Potentially Disappeared Fraction of species), climate change (kg CO₂ eq), and Resources (MJ primary). These data are given (Figures 7–10) in the range according to SimaPro 8.2.3.0 software program.

Figure 7. Human health damage category.

Figure 8. Ecosystem damage category.

Figure 9. Climate change damage category.

Figure 10. Resources damage category.

According to Figure 7, the loss of healthy life expectancy expressed in DALY units in years was determined as −5.7 months (−0.476084754 years), −21.6 months (−1.80254862), and 3.6 months (0.30112191) for Scenario 1, Scenario 2, and Scenario 3, respectively. The negative value of DALY indicates that there is no loss in a healthy life year, on the contrary, it makes a favorable contribution when compared to other alternatives. However, the positive value of DALY denotes the loss in healthy life years. Scenario 2 was determined as the most favorable in terms of human health and desired method on packaging waste management. On the contrary, the Scenario 3 was determined as the worst approach that decreases the healthy human life expectation by 3.6 month (0.30112191 years) in this study. The results are shown in Figure 7 for all the three scenarios.

Ecosystem quality: It covers aquatic ecotoxicity, terrestrial ecotoxicity, terrestrial acid/nutrient (terrestrial acid/nutrient), land occupation, acidification (aquatic acidification), eutrophication (aquatic eutrophication). This damage category is the species that are expected to disappear for a year in 1 m² of soil. For Scenarios 1 and 2, the species −449,038.19 −1,651,473.79 PDF×m²×yr were preserved, respectively, while for Scenario 3, 47,234.00013 PDF×m²×yr species were found to disappear. Increasing or decreasing the amount of waste sent to landfill affects this parameter. Scenario 2 also had far less impact on ecosystem quality, while, comparing the other scenarios, Scenario 3 is the most unfavorable scenario. The ecosystem quality of these three scenarios is given in Figure 8.

Climate change damage category is directly related with the greenhouse gases that cause global warming: carbon dioxide (CO₂), nitrous oxide (N₂O), methane (CH₄), chlorofluorocarbons (CFSc), hydro chlorofluorocarbons (HFCFs), and methyl bromide (CH₃Br) is a unit in which climate change effects are measured in terms of CO₂. According to the scenarios of the climate change impacts in terms of CO₂, a positive contribution of −199,557.9820, −611,183.7836 kg CO₂ eq was made for Scenario 1 and Scenario 2, respectively, and 783,479.9668 kg CO₂ eq negativity was calculated for Scenario 3 and is shown in Figure 9.

When the resources damage category is evaluated according to the data obtained from the scenarios, it is clear that −4,454,102.525, −15,845,253.840, 4,104,357.165 MJ for Scenarios 1, 2 and 3, respectively. It is seen in Figure 10 that energy use in Scenario 3 is considerably higher than the other two scenarios.

As it can be seen from Figures 7 to 10, Scenario 2 had the lowest values for four types of damage categories while comparing the other two scenarios. When all damage categories are taken into account, when the data obtained from Figures 7 to 9 are examined, it can be seen that the new Üsküdar Model, which is expressed in this study as Scenario 2, gives the most advantage in the packaging collection and evaluation system. In terms of human health, ecosystem quality, climate change, and resources, Scenario 2 which is applied from 2016 in Uskudar District really gives the best applicable model on packaging management besides the other Scenario 1 and Scenario 3. Especially, for all four damage assessment parameters, Scenario 2 leaves less negative footprint than the other two scenarios.

Evaluation of LCA according to material types

In this study, materials were also evaluated in terms of damage category according to their types in LCA analysis. Material-based damage category analysis results for these three scenarios are given in Table 5. For Scenario 1 and Scenario 2, the recycling effect for each material is greater than for Scenario 3. Since the most paper material is recycled, a positive effect has been achieved in paper packaging material in all damage categories. Although aluminum is the least recycled material, it is seen that this material has the most impact in all damage categories compared to other packaging types.

Table 5. Damage category analysis of three different scenarios according to material types

Damage categories	Scenarios	Materials
		Aluminum	Glass	Iron	Paper	PE	PET	Plastic
Human health, DALY	S1	−0.036372	0.004828	−0.0059868	−0.391118	−0.017088	−0.0066172	−0.023739
	S2	−0.134099	0.002675	−0.022064	−1.441718	−0.062997	−0.024403	−0.087497
	S3	0.000665	0.003838	0.00087	0.075983	0.004942	0.000334	0.003716
Ecosystem.
PDF×m^2×yr	S1	−693.022096	722.1397	−711.9723	−447,159.3346	294.72837	−538.402212	−952.54924
	S2	−2555.285667	400.02193	−2625.0773	−1,648,294.982	1086.41309	−1984.710095	−3511.32069
	S3	1783.992	401.1655	125.2745	10,855.81	676.1047	45.88205	510.4934
Climate change. kg CO2 eq	S1	−23,928.69704	−11,732.953	−5514.89267	−107,781.988	−24,459.8741	−3266.35465	−22,873.1406
	S2	−88,228.97782	−6497.486	−20,333.4935	−397,300.88	−90,162.823	−12,040.75205	−84,315.7067
	S3	503.1436	3585.734	1925.408	221,578.3	8287.493	476.2678	5560.186
Resources. MJ primary	S1	−255,163.9953	17,031.92	−49,425.1222	−1,696,139.72	−1,357,527.135	−96,365.2141	−1,016,512.498
	S2	−940,833.213	9444.84	−182,230.519	−6,252,224.2	−5,004,049.18	−355,230.111	−3,747,100.75
	S3	7921.229	60,635.02	1214.72	1,000,649	77,351.66	5243.379	58,175.85

For example, when the human health category is examined on the basis of materials recycled on packaging management, according to Table 5 as DALY unit, the loss of healthy life expectancy was resulted in approximately −4.7 months (−0.391118 years) for Scenario 1 and −17.3 months (−1.441718 years) for Scenario 2 in paper packaging waste. As known, the “−“ sign in DALY denotes gain not loss for healthy life duration. According to data given in Table 5, if the paper is disposed instead of recycled, the DALY value determines as 0.91 months (0.075983 years) defining as lost time in a healthy life year for Scenario 3. For aluminum, although the amount is small, it is seen that there is a −0.44 months (−0.036372) gain for Scenario 1, a −1.6-month (−0.134099 years) gain for Scenario 2 and a 0.008 months (0.000665 years) loss effect for Scenario 3 according to values given in Table 5.

According to Table 5 it is understood that, for Scenario 1 and Scenario 2, −447,159.3346, −1,648,294.982 PDF×m²×yr species are preserved, and for Scenario 3, 10,855.81 PDF×m²×yr species are extinct for paper packaging waste.

When the climate change parameter was examined in the damage category analysis in terms of CO₂ emitted, it was determined that the most effective parameter according to Table 5 was paper packaging. In addition, although the amounts are small, it is seen that the effective range of aluminum, PET, and plastic is also very high. The emission of 107,781.988 kg CO₂ eq for Scenario 1 and 397,300.88 kg CO₂ eq for Scenario 2 was prevented for paper, and 221,578.3 kg of CO₂ eq was determined for disposal Scenario 3.

The resources category is a damage category related to the amount of energy expended. When the Impact and Damage Categories were examined for all scenarios, it was observed that the negative environmental impacts were reduced if the Uskudar Model (Scenario 2), which was offered as an alternative to the CCS (Scenario 1), was preferred. In Scenario 3, it has been determined that it has significant negative effects on human health, climate change, and resources. In this study, it was determined that even with the change made on the method of collecting packaging wastes separately at the source, the environmental gains obtained would be at significant levels, and these gains were clearly demonstrated by LCA analysis qualitatively and quantitatively.

Conclusion

In this study, it has been revealed that to what extent environmental contributions have developed positively only with the development of a new collection system for packaging waste. When the packaging wastes are compared with the Scenario 1 and Scenario 2, it has been observed that a significant increase in the amount of packaging waste as 2.8-fold has been achieved with this new collecting model approach alone. When compared in terms of total cost, Scenario 2 is 189% more profitable than Scenario 1. In addition, due to the higher content quality of the recycled packaging wastes in Scenario 2 was achieved.

When the system was examined in terms of human health damage category, the loss of healthy life expectancy is −5.7 months and −21.6 months for Scenario 1 and Scenario 2, and 3.6 month loss for Scenario 3, respectively. This value is determined that Scenario 2 is the most favorable scenario for human health, and Scenario 3 the most unfavorable one.

When the results of the study in terms of ecosystem quality are examined, the species expected to disappear for one year are −449,038.19, −1,651,473.79, 47,234.00013 PDF×m²×yr for Scenario 1, Scenario 2, and Scenario 3, respectively. The increase or decrease in the amount of waste sent to landfill affects this parameter. Scenario 2 is the most favorable method in terms of ecosystem quality, and Scenario 3 is the worst one.

When the effects of the three scenarios on climate change were examined in the study, it was calculated as −199,557.9820, −611,183.7836, 783,479.9668 kg CO₂ equivalent for Scenarios 1, 2 and 3, respectively. From these values, it is understood that especially Scenario 3 has more negative effects on climate change than the other two scenarios, while Scenario 2 has the lowest impact and is the best desired method.

When the source damage categories of all scenarios are evaluated in this study, it is seen that for Scenario 1, 2 and 3, it is −4,454,102.525, −15,845,253.840, 4,104,357.165 MJ, respectively. Scenario 2 produced the best solution among the other two scenarios in terms of resources (MJ primary).

Impact and Damage Categories were examined for all scenarios, and it was observed that the negative environmental impacts were reduced if the Scenario 2, which was offered as an alternative to the classical collection system, was preferred. In Scenario 3 it has been observed that there are negative effects on human health, climate change and resources. As a result, it has been revealed that satisfactory results have been achieved with the LCA analysis in environmental gains obtained even with a small change in the method of collecting packaging wastes separately at source.

Disclosure statement

No potential conflict of interest was reported by the author(s).

Additional information

Notes on contributors

Yasar Avsar

Yasar Avsar, Prof. in Yildiz Technical University, Civil Engineering Faculty, Department of Environmental Engineering. Research Areas: Environmental Engineering, Environmental Sciences, Environmental Chemistry, Environmental Technology, Wastewater Collection and Treatment, Environmental Impact Assessment, Ecology and Pollution, Industrial and Hazardous Waste Management, Noise Pollution Control, Water Pollution and Control, Water Supply and Treatment, Hazardous Waste Management.

Fatma Uksal

Fatma Uksal, Yildiz Technical University Civil Faculty, Environmental Engineering Department Master of Science: Yildiz Technical University Civil Faculty, Environmental Engineering Department Work experience: Uskudar Municipality Waste Management Department, Istanbul-TURKEY Research Areas Industrial and Hazardous Waste Management and their control, Packaging waste management.

Levent Bilgili

Levent Bilgili, Associated Professor in Yildiz Technical University, Faculty of Ship Building and Maritime, Ship Construction and Ship Machinery Engineering Department Master of Science: Yildiz Technical University, Institute of Sciences, Ship Construction and Marine Machinery Engineering Doctor of Philosophy: Yildiz Technical University, Institute of Sciences, Ship Construction and Marine Machinery Engineering Scientific Study Areas Road Transport Emission Modelling, Life Cycle Evaluation Workshop and Training, Ship Oriented Air Pollution and its Control, Risk Assessment, Risk Management and Accident Examination, Root Cause Analysis. After graduating from Yildiz Technical University as a Naval Architecture and Marine Engineer in 2011, he completed his master and doctorate degrees at the same university and department in 2014 and 2018, respectively. In 2020, he received the title of associate professor in the same field. He has been working as a faculty member at Bandirma Onyedi Eylul University since 2017 and has studies on ship emissions, life cycle assessment, ship energy efficiency and artificial neural networks.