ENVIRONMENTAL ENGINEERING SCIENCEVolume 25, Number 8, 2008© Mary Ann Liebert, Inc.DOI: 10.1089/ees.2007.0164

Characterization of the Municipal Solid Waste in Eskisehir City, Turkey

Müfide Banar* and Aysun Özkan

Faculty of Engineering & ArchitectureDepartment of Environmental Engineering

Anadolu UniversityIki Eylul Campus

26555, Eskisehir, Turkey

Received date: June 26, 2007 Accepted in revised form: November 16, 2007

Abstract

The solid waste, namely municipal solid waste, generated in big cities, is a mixture of all kinds of materialsproduced by many industries for the use of human beings where they throw away the unusable parts all to-gether in containers or plastic bags. Such kinds of mixed material consists of recyclable components that willbe used for the production of secondary materials and nonrecyclable components, which will be treated to pro-duce some other matter for conservation of natural sources and the sake of environment. In order to design asustainable managing system of municipal solid waste (MSW) components (MSWC), the generation rate of,percentage of, and some properties of each component in MSW have to be known. In this study, it has beeninvestigated to determine some data about the MSWC generated by the community in order to support the in-tegrated solid waste management system in Eskisehir, Turkey. Therefore, samples of MSW have been collectedfor a year to determine the change in MSWC with season and socioeconomic structure of residents. On theother hand, SPSS 10.0 statistical software was used to determine the correlation coefficients of MSWC and higherheating value (HHV) relative to the temperature of seasons and socioeconomic structure of the residents. Forthe determinations of the amount of MSWC, the MSW samples, collected, were separated into the groups of:paper–cardboard, metals, glass, plastics, food wastes, ash, and miscellaneous, manually. The current situation,including recycling and recovering of MSWC and disposing of solid waste in Eskisehir, was characterized. Also,moisture content and higher heating value of the waste were determined. It was found that the percentages ofthe components of the solid waste (on a wet basis) in Eskisehir were: paper–cardboard 10.07%, metals 1.26%,glass 2.49%, plastics 5.62%, food wastes 67.06%, ash 3.86%, and miscellaneous 9.64%. According to statisticalanalysis, it was seen that the effects of socioeconomical changes on waste composition is very great. It was con-cluded that local authorities must use these results to achive a sustainable and an integrated solid waste man-agement system for the evaluation of all the components.

Key words: municipal solid waste; municipal solid waste components; socioeconomic factors; seasonal varia-tion

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Introduction

EFFECTIVE AND SUSTAINABLE SOLID WASTE MANAGEMENT canbe achieved by only basing it on the percentage and gen-

eration rate of municipal solid waste components (MSWC).All the data about MSWC is important for numerous rea-sons, including the need to estimate material recovery po-tential, to identify sources of components, to design the capacities of collecting, transporting, and processing equip-

ments, to calculate the potential and economies of secondaryproducts from the components according to physical, chem-ical, and thermal properties of the waste, and to maintaincompliance with national law and European directives (Gi-darakos et al., 2006). To develop and implement the effectivestrategies to meet these targets requires reliable informationon the composition of all parts of the MSW stream (Burnleyet al., 2007). The composition of waste generated is extremelyvariable as a consequence of seasonal variations, lifestyle ofthe population, demographic structure, geographic condi-tions, and legislation impacts. It was reported (Gidarakos etal., 2006) that the variability in components of MSW makesdefining and measuring the composition of waste more dif-ficult, and at the same time more essential. A review of the

*Corresponding author: Faculty of Engineering & Architecture, De-partment of Environmental Engineering, Anadolu University, IkiEylul Campus, 26555, Eskisehir, Turkey. Phone: �90-222-321 35 50ext. 6400; Fax: �90-222-323 95 01; E-mail: mbanar@anadolu.edu.tr

literature shows that research have been conducted in orderto investigate the composition of municipal wastes (AbuQdais et al., 1997; Daskalopoulos, 1998; Mohee, 2002; Ojeda-Benitez et al., 2003; Gidarakos et al., 2006; Shaw et al., 2006;Tinmaz and Demir, 2006; Burnley, 2007; Burnley et al., 2007;Chang and Davila, 2007; Igoni et al., 2007; Sha’ato et al., 2007;Sharma and McBean, 2007).

The purpose of this study was to determine the percent-age of MSWC in Eskisehir in order to support the design ofan integrated solid waste management system. Therefore, a1-year research program was prepared to determine reliabledata on solid waste components, and some properties dueto seasonal variation in MSW generated by the communitiesin Eskisehir/Turkey. From the data obtained, the effects ofthe seasonal changes and variations in socioeconomic factorson waste composition data collected in this study were alsoevaluated statistically using SPSS 10.0 software. This is infurtherance of Regulation (EC) No 2150/2002 of the Euro-pean Parliament and of the Council of 25 November 2002 onwaste statistics, which requires member states to realize sta-tistics on the generation rate and percentages of the recy-clable components to recover, and of the percentage of com-ponents to dispose for the design of a sustainable integratedMSW system.

MSW Management in the City of Eskisehir

Eskisehir is located in the northwest of the Central Ana-tolia region in Turkey (Fig. 1) and the city has an area ofabout 13,652 km2 (13.7 Mm2). Projection of population was

made according to the census of 2000 and population of thecity was obtained as 591,296 habitants in 2006. The MSW pro-duction rate in winter and summer seasons in Eskisehir are790 and 700 tons/day, respectively, and average daily MSWproduction rate in Eskisehir is 750 tons/day (personal com-munications with submunicipalities).

Recently, MSW in Eskisehir was disposed of and reservedin a landfilled area known as an unregulated dumping site,determined by the Metropolitan Municipality of Eskisehir.The two private companies that are employed by the twosubmunicipalities have been used collecting the MSW inplastic bags that are discarded and piled up in the streets bythe residents. The wastes in plastic bags are collected andtransported to the unregulated dumping site, dumping at allhours of the day in an unregulated way by the vehicles. Thisunregulated dumping site is an open area where the recy-clable components of the waste are approximately 7% of to-tal waste (by mass) separated manually under unhygienicconditions and piled up there to recycle. The dumping siteis filled by household wastes, some industrial wastes, andhealthcare wastes. The MSW has been dumped unregularlyon the surface of the natural valley since 1986, and about 2.5Mm3 MSW have been held in as reserved there (Banar et al.,2007). Recovery of the recyclable components, separated,piled up, and scavanged at the dumping site is limited, andcarried out by scavengers. There is no data on the numberof scavengers or on the amount of materials salvaged bythem. Scavengers salvage glass, metals, papers, and card-board. Scavengers have no facilities or equipment for sort-ing valuable materials from the solid waste. Unfortunately,

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TABLE 1. NUMBERS AND TOTAL NUMBERS OF DISTRICTS ACCORDING TO SOCIOECONOMIC

LEVELS OF TEPEBASI AND ODUNPAZARI MUNICIPALITY IN ESKISEHIR

High income Middle income Low income Total

Tepebasi Municipality 2 19 11 32Odunpazari Municipality 7 13 12 32Total 9 32 23 64

FIG. 1. Map of Eskisehir.

they suffer from health problems and injuries due to dustand the presence of broken glass and sharps.

Materials and Methods

In this study, according to the collection program of solidwastes in Eskisehir, the MSW sampling program was per-formed, and 562 solid waste samples in plastic bags from 64different locations (Table 1) were taken to our laboratory bythe municipal staff in October 2005–September 2006. The res-idents store all kinds of waste components in plastic bags inthe residens, and they put them curbside in front of the build-ing on the street from where MSW collecting vehicles collectand transport them to the dumping site in Eskisehir. There-fore, each sample in the plastic bag was taken up on thestreets where the waste collection regions are random. Thesesamples were taken before any separation was applied byscavengers. The amount of collected samples from the loca-tions was determined by weighing, and it was found thatthe amount of the samples changes in between 40 and 105kg/day. The locations where the samples taken were classi-fied into three groups of the families being in the high-, mid-dle-, and low-income levels, and the findings from the studywere evaluated according to these groups (Table 1). It wasconsidered that extended families that have a low-incomelevel, a low cultural level, and single flat homes were clas-sified as low-income level. The civil servants that have ahigher cultural level resided in the regions that are called themiddle-income level. However, the businessmen that havethe highest cultural and income levels resided in the regionsthat are classified as a high-income level. Also, sample num-bers and total number of samples according to locations andseasons are given in Table 2.

For the determination of the mean composition of MSW,the components of the known amount of samples weresorted manually. After manual sorting of the solid waste

sample into components, the amount of each component wasdetermined gravimetrically, and the mass percentage of eachcomponent was calculated by using the mass of the compo-nents from the known amount of the sample used.

For determination of moisture content, the subsampleswere prepared. First, aluminum cans, paper, glass materials,etc., due to the physical properties in appearance were sep-arated manually from the collected samples, and the rest ofthe samples that contains mostly organics in nature wereused for determination of moisture content. For higher heat-ing value analysis, subsamples were prepared according tothat based on weights of each fraction. Moisture content wasdetermined immediately, and the samples were preserved at�4°C in small glass jar in a refrigerator for subsequent anal-ysis of higher heating values (HHV).

For moisture content determination, 80–100 g of biode-gradable samples was placed in a glass vessel, and kept at

MUNICIPAL SOLID WASTE IN ESKISEHIR CITY 1215

TABLE 2. NUMBERS AND TOTAL NUMBERS OF SAMPLES

ACCORDING TO LOCATIONS CODED AND SEASONS

Location code Winter Spring Summer Autumn Total

TMhigh 6 — 4 2 12OMhigh 25 23 18 16 82

Subtotal 31 23 22 18 94TMmiddle 59 38 39 32 168OMmiddle 38 44 26 26 135

Subtotal 97 82 65 58 302TMlow 5 42 16 27 90OMlow 9 26 10 31 76

Subtotal 14 68 26 58 166Total 142 173 113 134 562

TMhigh: locations with high-income levels for TepebasiMunicipality.

OMhigh: locations with high-income levels for OdunpazariMunicipality.

TMmiddle: locations with middle-income levels for TepebasiMunicipality.

OMmiddle: locations with middle-income levels for OdunpazariMunicipality.

TMlow: locations with low-income levels for TepebasiMunicipality.

OMlow: locations with low-income levels for OdunpazariMunicipality.

FIG. 2. Percentage of MSW components in Eskisehir (% bymass on wet basis).

FIG. 3. Percent distribution of the recyclable componentsof MSW (% by mass on wet basis).

room temperature for a definite period. Then, these sampleswere ground and reduced to particle sizes smaller than 0.5mm. Then the samples were put into a Petri dish of knownmass and the total amount was determined gravimetrically.The samples in the Petri dishes were left to dry to constantmass in an oven at 75°C for 24–48 h, cooled in a desiccator,and the amount of total dried mass were determined gravi-metrically. The percentage of moisture was calculated fromthe difference [Turkish Standards (TS) 10459, 1992].

The 83 subsamples, prepared from the samples collectedweekly and mixed with the samples from the same locationsin the same season were used for determination of the HHV.The HHV of the samples was determined by using a com-mercial bomb calorimeter according to ASTM D 5865. Tomeasure enthalpies of combustion, a known amount ofwastes in a Gallenkamp AutoBomb calorimeter was burnedand the temperature change was determined. A HHV ofsamples was calculated by using the formula below:

HHV (cal/g)

� [(Amount of water � Calorimeter constant)� Temperature difference (°C) � Additional heat]

Amount of samples(g)

Here, Amount of water � 2,000 mL, calorimeter constant �377, and additional heat � 15.5 cal.

Using SPSS 10.0 software, multivariate Pearson analysiswas performed on the data obtained, to indicate the possi-ble relationships between the analyzed parameters and me-teorological data. Correlation analysis was done by using

mean values of analysis results in all sampling points. Val-ues in Tables 5 and 7 (Pearson correlation coefficient) showsthe degree of relationship between two variables. If this cor-relation coefficient is negative, an inverse relationship exits.However, if this coefficient is positive, the determined vari-ables, increase or decrease together. Relationship betweenthe variables is very poor when the coefficient is near zero.If this coefficient is greater than 0.5 (especially near 1), it canbe decided that there is a good correlation between two vari-ables. Correlation coefficients are statistically significantwhen the significance coefficient is smaller than 0.05. In thisstudy, for the Pearson correlation coefficient of 0.7 or greaterthan 0.7, it can be decided that there is a good correlationbetween two parameters, and these results can be evaluatedaccording to this coefficient. Also, the parameters having thesignificant coefficients smaller than 0.05 can be shown thatthere is a relationship between the corresponding variables.

Results

The composition of the MSW in general was evaluated,and the percentage of components of the MSW in Eskisehiris shown in Fig. 2.

As seen in Fig. 2, the food waste, namely the nonrecyclablecomponent of waste, occupies a large proportion of the MSW(67.06%). This can be explained by the fact that there is aminimum use of processed food in the feeding habits in Es-kisehir. People are still in favor of preparing fresh food fromfresh vegetables and fruits. It was noted that there is an im-portant difference in the percentages of food wastes in the

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TABLE 3. PERCENTAGES OF MSWC IN MAJOR CITIES OF TURKEY (%, BY WEIGHT)

ESKISEHIR(this study) BURSAa ISTANBULa IZMIRa ADANAa MERSINa

Population (people) 591,296 1,958,529 9,198,809 3,114,859 1,682,483 1,508,232Food wastes 67.04 53.1 43.0 46.0 64.4 63.00Paper/cardboard 10.07 18.4 7.8 12.0 14.8 18.42Plastic 5.62 11.6 14.2 12.0 5.92 6.69Metal 1.26 3.0 5.8 3.0 1.40 1.25Glass 2.49 3.4 6.2 4.0 3.08 3.08Other 13.50 10.5 23.1 23.0 11.40 7.60

aMetin et al., 2003.

TABLE 4. HIGHER HEATING VALUES (HHV), MOISTURE CONTENT, AND

PERCENTAGE OF WASTE COMPONENTS DUE TO SEASONS IN ESKISEHIR

% (by mass on wet basis)

Moisture HHV Paper– Food% (by mass) MJ/kg cardboard Metal Glass Plastic Waste Ash Miscellaneous

Winter Mean 34.9 13.16 13.40 1.44 2.88 5.75 57.99 4.97 13.57SD 14.6 5.95 11.20 1.90 2.30 4.00 15.40 7.90 9.10

Spring Mean 37.5 13.84 8.85 1.01 3.42 5.51 67.19 2.91 11.12SD 16.3 4.64 6.40 2.10 4.50 5.00 13.50 6.60 10.40

Summer Mean 37.7 12.80 10.85 1.83 2.36 5.83 72.95 0.05 6.13SD 15.3 2.39 9.10 3.00 2.90 4.80 15.10 0.20 7.50

Autumn Mean 37.5 13.29 7.18 0.73 1.31 5.41 70.11 7.53 7.74SD 13.3 3.34 7.00 0.90 1.40 4.70 15.70 8.50 9.00

MSWC generated by developed and industrialized coun-tries. The percentage of biodegradable materials in theMSWC produced in industrialized countries like the UnitedStates is generally less than the percentages in developingcountries. Tchobanoglous et al. (1993) reported that the per-centage of food wastes in MSW in the United States is about9%, which is very much lower than the result in Eskisehir.The percentages of metal and glass (1.26 and 2.49%, respec-tively) are found to be lower than the percentages of othercomponents. These bottles are recovered and reused by theirmanufacturers and housewives. The percentages of plasticsand papers are relatively high. A high percentage of paperwaste (10%) in the residental region was noted. Also, the per-centage for plastics is 5.6%.

The percentages of recyclable components of MSW aregiven in Fig. 3. As seen in Fig. 3, the percentages of plastics,glass, and metals are 29, 13, and 6.5%, respectively, and thepercentage of paper–cardboard is 52%, higher than the otherrecyclable components.

As an overview, data about the MSWC for major cities inTurkey and Eskisehir are provided in Table 3. This tableshows that the major component of the MSW is an organicstructure, whereas recyclable materials (paper–cardboard,glass, metal, and plastic) constitute almost 1/3 of total MSWin big cities. Moreover, Table 3 represents the comparativedata of typical content variation of MSW with the demo-graphic, social, and economic differences.

On the other hand, the HHV of the determined wastes, is12.7 MJ/kg (3,041 kcal/kg) in wet basis (Table 4). Comparedto the range of higher heating values of various fuels intoconsideration (Fig. 4), the mixed MSW had low higher heat-ing value, comparable to materials like bagasse and mixedpaper. Figure 4 shows that the higher heating values of othermaterials (Mohee, 2002) and of the mixed MSW in Eskisehir,results of this study.

Seasonal variation of the MSW

HHV, moisture content, and percentage of waste compo-nents due to seasons in Eskisehir for the period of October2005–September 2006 are shown in Table 4, and statisticalevaluation of the results is given in Table 5. As seen in Table4, the percentages of ash in winter, autumn, and spring sea-sons are 4.97, 7.54, and 2.91, respectively. During these sea-sons, because coal as fuel is used for heating the detachedhouses and some apartments, the percentage of ash is higherthan in summer. It is also seen that the percentages of foodwaste in the spring and summer seasons (67.19 and 72.95%,respectively) increase with the increase of vegetable and fruitproduction and consumption. Moisture content is a very im-portant parameter for the selection of solid waste managingand processing systems (composting, incineration, etc.).Table 4 is used to evaluate the waste in case of moisture con-tent. As seen in Table 4, moisture contents of waste in dif-

MUNICIPAL SOLID WASTE IN ESKISEHIR CITY 1217

TABLE 5. CORRELATION COEFFICIENTS OF THE WASTE

COMPONENTS AND HIGHER HEATING

VALUES (HHV) RELATIVE TO TEMPERATURE

CorrelationParameters coefficients

Temperature 1.000Moisture 0.812a

HHV �0.341Paper �0.298Metal 0.415Glass �0.128Plastic 0.252Food waste 0.896a

Ash �0.723a

aCorrelation is significant at 0.05.

FIG. 4. Higher heating values of subsamples from MSW and some other materials.

ferent seasons are very similar to each other. Furthermore,Table 4 show that the HHV of samples increase, especiallyin the spring period due to an increase of packaging mate-rials and decrease of ash content.

As seen in Table 4, the percentages of packacing materialare not changed in the different seasons. On this account, itwas found that there are not any correlations between tem-perature and percentage of packaging material, as seen inTable 5. The percentage of the component defined as mis-cellaneous waste is increased in the winter and spring peri-ods especially. In this category, there are yard wastes, de-molition wastes, textiles, and napkins. An increase in thiscomponent is a result of an increase in the amount of yardwastes during these seasons (13.56 and 11.12%, respectively).

Socioeconomical variation of the MSW

In this section, the findings are evaluated according to theregion and socioeconomic levels of the residents in Table 1.Mean and SD of percentages of MSWC according to socio-economic levels are given in Table 6, and the correlation co-efficient of the waste components relative to socioeconomiclevels were derived by statistical evaluation and given inTable 7. We were not able to find a relationship for HHVwith the socioeconomic structure of the residents, becausethe samples, collected every week, were mixed and used fordetermination of HHV. Table 6 revealed that there is a strongcorrelation between certain socioeconomic levels and solidwaste composition.

In Table 6, it is seen that the percentages of paper–card-board, glass, metal, and plastic (15.75, 3.12, 3.61, and 9.28%,respectively) are higher in regions where the high socioeco-nomic level residents live than the percentages of these com-ponents in the regions where the low socioeconomic levelresidents live. There is no ash in the regions where high-in-come level population are, while the percentage of ash ishigh in the regions where families having low incomes liveand use the coal as fuel, and where there is no natural gaspipeline networks. Miscellaneous wastes contain napkins incentral districts and demolition and yard wastes in other dis-tricts. As seen in these tables, the percentage of food wastesincreased with a decrease in socioeconomic levels, whilepackaging materials are higher in regions settled by high-in-come levels than the other district where high-income fam-ilies live. As seen in Table 6, moisture contents of waste fromdifferent regions are very similar to each other. But gener-ally, the moisture content decreases with an increase in theincome level.

Conclusion

In Turkey, as in the rest of the world’s developing coun-tries, there is a great need to reduce the volume of MSW,which have as their final destination the local low-gradelandfill (dump). Furthermore, legal rules that were changedfor the purpose of harmonization of the European Unionobliged to Turkey to change the environmental policy. Newrules that have been passed have more obligations and havemore definite limits than the older rules. Therefore, solidwaste authorities have to consider the limits in IntegratedSolid Waste Management Planning.

In Eskisehir, there is a great environmental risk associatedwith the management of MSW, as there is no sanitary landfill.In this context, this study becomes very important, being thefirst and only one research related to the composition of theMSW in Eskisehir/Turkey. So solid waste composition was de-termined during 1 year for Eskisehir/Turkey. The results hadshown that food waste was a large proportion of the waste(67.06%). Total percentage of recyclable wastes was found tobe approximately 20%. But these findings change with espe-cially socioeconomic conditions. Also, mixed municipal solidwaste was seen to have a low HHV (12.7 MJ/kg) and moisturecontent of 37%. These data will be formed on the basis of stud-ies related to development of an integrated solid waste man-agement system. These efforts will greatly support decisionmaking for municipal authorities.

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TABLE 6. MEAN AND SD OF PERCENTAGES OF MSWC ACCORDING TO SOCIOECONOMIC LEVELS

% (by mass on wet basis)

Moisture Paper– Food% (by mass) cardboard Metal Glass Plastic Waste Ash Miscellaneous

High income Mean 35.7 15.75 1.61 3.12 9.28 62.76 0.00 6.54SD 17.8 21.20 4.10 6.80 12.60 30.30 0.00 15.10

Middle income Mean 36.0 12.07 1.24 3.14 6.27 64.40 2.97 9.90SD 15.0 16.00 5.00 10.20 11.40 30.10 13.10 19.80

Low income Mean 39.5 4.88 1.30 2.02 4.15 68.53 6.92 12.19SD 14.8 9.90 5.10 5.60 9.90 29.10 16.10 24.20

SD � standard deviation.

TABLE 7. CORRELATION COEFFICIENT OF THE WASTE

COMPONENTS RELATIVE TO SOCIOECONOMIC LEVELS

CorrelationParameters coefficients

Income level 1.000Moisture �0.899a

Paper 0.983a

Metal 0.781a

Glass 0.858a

Food waste �0.970a

Plastic 0.995a

Ash �0.997a

aCorrelation is significant at the differences of 0.05.

Acknowledgments

This study was financially supported by Anadolu Uni-versity (Project No. 050239). Also, agreements were realizedwith Tepebası and Odunpazari Municipality.

Author Disclosure Statement

The authors declare that no competing financial interestsexist.

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