Separation of PET and PVC by Flotation Technique Without Using Alkaline Treatment

This article was downloaded by: [Ünzile Yenial]On: 21 June 2013, At: 00:15Publisher: Taylor & FrancisInforma Ltd Registered in England and Wales Registered Number: 1072954 Registeredoffice: Mortimer House, 37-41 Mortimer Street, London W1T 3JH, UK

Mineral Processing and ExtractiveMetallurgy Review: An InternationalJournalPublication details, including instructions for authors andsubscription information:http://www.tandfonline.com/loi/gmpr20

Separation of PET and PVC by FlotationTechnique Without Using AlkalineTreatmentÜ. Yenial a , F. Burat a , A. E. Yüce a , A. Güney a & M. O. Kangal aa Mineral Processing Engineering Department, Faculty of Mines,Istanbul Technical University, Maslak, Istanbul, TurkeyAccepted author version posted online: 11 Jul 2012.

To cite this article: Ü. Yenial , F. Burat , A. E. Yüce , A. Güney & M. O. Kangal (2013): Separationof PET and PVC by Flotation Technique Without Using Alkaline Treatment, Mineral Processing andExtractive Metallurgy Review: An International Journal, 34:6, 412-421

To link to this article: http://dx.doi.org/10.1080/08827508.2012.702705

PLEASE SCROLL DOWN FOR ARTICLE

Full terms and conditions of use: http://www.tandfonline.com/page/terms-and-conditions

This article may be used for research, teaching, and private study purposes. Anysubstantial or systematic reproduction, redistribution, reselling, loan, sub-licensing,systematic supply, or distribution in any form to anyone is expressly forbidden.

The publisher does not give any warranty express or implied or make any representationthat the contents will be complete or accurate or up to date. The accuracy of anyinstructions, formulae, and drug doses should be independently verified with primarysources. The publisher shall not be liable for any loss, actions, claims, proceedings,demand, or costs or damages whatsoever or howsoever caused arising directly orindirectly in connection with or arising out of the use of this material.

SEPARATION OF PET AND PVC BY FLOTATIONTECHNIQUE WITHOUT USING ALKALINE TREATMENT

U. Yenial, F. Burat, A. E. Yuce, A. Guney, and M. O. KangalMineral Processing Engineering Department, Faculty of Mines, IstanbulTechnical University, Maslak, Istanbul, Turkey

PET and PVC cannot be separated by gravity separation techniques due to their close

density. For this reason, plastic recycling needs other separation techniques. Froth flotation,

which is used in mineral processing, could be useful because of its low cost and simplicity.

The main objective of this research is to investigate the flotation characteristic of PET and

PVC and determine the effects of plasticizers on plastic separation without any alkali

pre-treatment. In selective flotation experiments, water bottles and waste water pipes were

used for this purpose, and Triton XL-100N and diethylene glycol dibenzoate were used as

plasticizers. Various parameters such as pH, plasticizer concentration, conditioning time,

and flotation time were investigated. According to the results, PET particles were floated

with 100% purity, and the product remaining in flotation cell (PVC particles) was obtained

with 86.1% purity.

Keywords: alkaline treatment, flotation, PET, PVC

INTRODUCTION

The production of plastic has grown significantly in the world. Almost31 million tons of plastic waste was generated in 2010, representing 12.4% of totalMSW (EPA 2012). Strength of plastics and their long life are responsible for thisincrease. Plastics have lighter weight, and reduce transportation costs. They are alsoresistant to chemical, water and impacts. They have excellent thermal and electricalinsulation properties. However, plastics have harmful chemicals which have a badeffect on human health. Most types of plastics are non-degradable and take a longtime to break down when they are landfilled (Siddique, Khatib, and Kaur 2007).

Plastic wastes have an immense impact on the environment because of theirnon-biodegradability. Recycling is the most effective way to dispose of plasticwastes, and segregation of different types of plastics is an important process in wasteplastics recycling. There are some methods for recycling plastics, such as chemicaland mechanical. Chemical methods are based on converting polymers into chainchemicals for re-use. Cracking, gasification, hydrogenation and pyrolysis could beconsidered as different methods of chemical recycling (Mapleston 1993). Up untilnow, only gravity separation and skin flotation techniques have been used on

Address correspondence to M. O. Kangal, Mineral Processing Engineering Department, Faculty of

Mines, Istanbul Technical University, Maslak, Istanbul 34469, Turkey. E-mail: [email protected]

Mineral Processing & Extractive Metall. Rev., 34: 412–421, 2013

Copyright # Taylor & Francis Group, LLC

ISSN: 0882-7508 print=1547-7401 online

DOI: 10.1080/08827508.2012.702705

412

Dow

nloa

ded

by [

Ünz

ile Y

enia

l] a

t 00:

15 2

1 Ju

ne 2

013

industrial scale (Curlee and Das 1991; Mikofalvy and Boo 1992; Super, Enick, andBeckman 1992; Vane and Rodriguez 1992).

PVC contamination in other plastics is a major concern. Even very low quan-tities of PVC damage the mechanical properties of PET. PVC can form acids whenmixed with PET during processing. These acids break down the physical and chemi-cal structure of PET. In addition, the presence of PVC may result in outgassing ofchlorine vapors during certain stages of PET reprocessing (CWC, 1997). Commercialuse of PVC=PET separation process has to be capable of removing all PVC fromPET down to less than 10 ppm PVC (Drelich et al. 1999).

Plastic residues contain four important groups, PET, PVC, PE and PP. Thebiggest components of plastics are PET and PVC. When PET and PVC are presentin mixture, it is difficult to separate them due to only a slight difference in their den-sities. PET density varies from 1.33 g=cm3 to 1.37 g=cm3 and PVC density is between1.32 g=cm3 and 1.37 g=cm3 (Dinger 1992). Not only the density of PET and PVC isclose but also their surface character is similar. The hydrophobicity of the plasticsis ordered as PS>ABS>PC>PET>PMMA>PVC>POM (Shen, Forssbergand Pugh 2001; Shen, Pugh, and Forssberg 2002a; Shen, Forssberg, and Pugh2002b; Fraunholcz 2004). Thus, PET and PVC can be separated from PP, PE, PSor HDPE through flotation methods.

Flotation has been widely used in mineral separation applications for hundredyears. The idea of applying this technique to plastic separation is currently new, andresulted from ore separation. Flotation method is based on surface properties suchas hydrophilic and hydrophobic, and this difference is provided by surfactantadsorption (Ehrig 1992).

In literature, flotation method was applied to different mixtures and types of poly-mers such as PET-PE-PP, PET-PS and PET-POM-PVC. Dodbiba et al. (2002) usedfroth flotation method to separate PET, PE and PP mixtures and found that PETcomponent selectively separated from PET-PE or PET-PP mixtures. Bartolo et al.(2004) used froth flotation method to separate PET from PS by using sodium-lignin sul-phonate, arabic gum and tannic acid as wetting agent. It is stated that pH, wetting agentand particle size are important factors in the flotation method. The same method wasapplied to separate PET-POM and PVC by using aluminum sulfate and calcium ligno-sulphonate as depressing agents. Considering their point of zero charge, polymersobtained with high content selectively (Takoungsakdakun and Pongstabodee 2007).Also, HDPE and PET were separated by flotation method after alkaline treatment. Tri-tonXL-100N and diethylene glycol dibenzoate were used as plasticizers at different tem-peratures. As a result, HDPE was concentrated from the mixture of HDPE and PETwith 100% content and 99.6% recovery (Kangal 2010).

Researchers used flotation method in some ways to separate PET and PVC.Some of them applied strong alkaline treatment before flotation to destroy hydro-phobicity of plastics. On this basis, this method involves treatment of alkaline solu-tions followed by plasticizer conditioning and then froth flotation. In this method,plasticizers are used for floating PVC particles. pH, temperature, particle size andplasticizers’ effect were investigated after alkaline treatment (Drelich et al. 1999;Burat, Guney, and Kangal 2009; Carvalho, Durao, and Ferreira 2010). This tech-nique was also tested with continuous pilot plant and 97.2% PET was obtained with1.1% PVC and 1.1% PS content (Carvalho et al. 2011). Unlike these studies, some

SEPARATION OF PET AND PVC 413

Dow

nloa

ded

by [

Ünz

ile Y

enia

l] a

t 00:

15 2

1 Ju

ne 2

013

researchers applied directly froth flotation without any previous alkaline treatment.In this method, calcium lignin sulphonate, tannic acid were used as wetting agentsand high purity of PET and PVC was obtained (Le Guern, Conil, and Houot2000; Marques and Tenorio 2000; Abbasi, Salarirad, and Ghasemi 2010).

In this present work, the effect of different plasticizers on separation ofpost-consumed polymers (PET and PVC) was investigated using column flotation,and tested on a laboratory scale. The investigated parameters are pH, plasticizerconcentration, conditioning time and flotation time.

MATERIAL AND METHODS

The samples of post consumed polymers, polyethylene terephthalate (PET) andpolyvinyl chloride (PVC), were obtained from Fuxing-Usas Plastic Company inTurkey. PET samples were soft drink bottles and PVC samples were waste waterpipes. Each plastic sample was shredded and classified into fractions of size,�3.36þ 2mm, and a feed mixture of 15 g PET and 15 g PVC was prepared to useat each experiment according to the previous study (Burat, Guney, and Kangal2009). Chemicals used for the flotation tests were – NaOH and HCl as pH adjuster;MIBC as a frother; and diethylene glycol dibenzoate (DIB) (Aldrich) and TritonXL-100N (BDH) as plasticizers.

The flotation experiments were carried out in a short column having a volumeof 5� 5� 25 cm3. The bottom of the flotation cell was fitted with a porous material(glass frit) for bubbling air. A column flotation cell generates small bubbles andhydrophobic particles can be taken from top through the bubbles (Figure 1). Theflotation tests were carried out at an ambient temperature, with 75L=h airflow rate.Tap water was used to prepare about 0.5 L of solution. In total, 30 g of PET andPVC mixture was stirred up with tap water and conditioned with plasticizer for3min. The amount of the frother (MIBC) was fixed to 1000 g=t in all experiments.After determining all parameters, a two-staged flotation experiment was made for

Figure 1 The column flotation unit.

414 U. YENIAL ET AL.

Dow

nloa

ded

by [

Ünz

ile Y

enia

l] a

t 00:

15 2

1 Ju

ne 2

013

further purification of PET and PVC. The floated and remaining product wascollected separately, then rinsed and dried. Due to difference of color between theplastics, all samples were separated easily by hand sorting. All samples were weighedand flotation recovery was calculated based on mass balance. The experiments wererepeated 3 times to prevent experimental mistakes.

RESULTS AND DISCUSSION

pH has an important role for changing surface characteristics of polymers. Onthis basis, post consumed PET and PVC particles were treated with plasticizers andoptimum pH, plasticizer concentration, conditioning time and flotation time wereinvestigated. Nonionic type Triton XL-100N and diethylene glycol dibenzoate wereused as plasticizers.

Effect of pH

To investigate the effect of pH on selective separation, PET and PVC particleswere subjected to flotation experiments without the addition of any plasticizers.MIBC was used as frother agent at the amount of 1000 g=t. The experimental resultsare given in Figure 2.

It is shown in Figure 2 that the flotation pH of PET=PVC mixture has a greatimpact on selectivity and recovery, for pH values from pH 4 to pH 10. PET particleshaving 86.4% content was floated with 88.9% recovery at pH 4. Recovery of PETwas observed to decrease when flotation was carried out in alkaline solutions andit reached the lowest at pH 8. Also, it is seen that the flotation recovery of PETincreases after pH 8. At same pH, content and recovery of PVC is maximized.

Fraunholcz, 1997 investigated electrokinetic potential of some polymers as afunction of pH. He found that zero point of charge (zpc) of PVC is pH 4. Also,

Figure 2 pH effect on PET and PVC flotation without any reagent.

SEPARATION OF PET AND PVC 415

Dow

nloa

ded

by [

Ünz

ile Y

enia

l] a

t 00:

15 2

1 Ju

ne 2

013

the zpc of PET was found between pH 3-pH 4.7 (Ratzsch, Jacobasch, and Freitag1990). Ozdilek 2011 used post consumed PET soft drink bottles to investigate theirsurface character depending on pH and found that PET’s zpc is pH 4.8. The differ-ence between the zpc of PET and PVC provides selectivity between pH 4-pH 4.8. Atthis range, PET particles are positively charged while PVC particles are negativelycharged. Thus both polymers are negatively charged above pH 4.8 and positivelycharged below pH 4.

To determine the effect of plasticizers on selective flotation of PET and PVCmixture Triton XL-100N and DIB were tested at different pH values. In theseexperiments, 1000 g=t of plasticizer concentration is an average amount, and therecovery and content of PET against plasticizers is shown in Figure 3.

Figure 3 clearly shows that DIB yielded better results against Triton XL-100Nin terms of selectivity and recovery. In flotation experiments where Triton XL-100Nwas added as plasticizer, PET was floated with 81.2% content and 81.1% recovery atpH 4. When DIB was added, the content and recovery of floated product was max-imized and found as 86.0% and 99.7%, respectively. When pH is increased to 8,recovery and content of PET dramatically decreases and PVC content increasesfor both plasticizers. It is obvious that the addition of DIB has a positive effecton increasing the recovery of PET.

Drelich et al., 1999 used DIB for removal of PVC and purification of PET intheir study. After alkaline treatment, virgin polymers were treated with DIB. Theyfound that while PET particles were sinking, PVC particles floated. In this study,DIB was used to depress PVC particles and PET particles naturally floated. Sincepost consumed polymers’ surfaces are covered with different pollutants, plasticizersaffect flotation oppositely.

Effect of Plasticizer Concentration

In order to determine plasticizer concentration, the experiments were underta-ken with optimum pH values. DIB and Triton XL-100N concentration were selected

Figure 3 pH effect on flotation with Triton and DIB.

416 U. YENIAL ET AL.

Dow

nloa

ded

by [

Ünz

ile Y

enia

l] a

t 00:

15 2

1 Ju

ne 2

013

between 250 and 1500 g=t. The effect of plasticizer concentration on PET and PVCseparation is shown in Figure 4.

In Figure 4, it is observed that as plasticizer concentration increases, PETrecovery and content also increase systematically. The best results were obtainedwhen plasticizer concentration was chosen as 1000 g=t. At this concentration, PETwas obtained with 81.2% content and 81.1% recovery for Triton XL-100N; and86.2% content and 99.7% recovery for DIB.

Effect of Conditioning Time

PET and PVC mixture was subjected to flotation experiments in order to deter-mine the effect of conditioning time. In these experiments, pH was chosen as 4 whereDIB and Triton XL-100N added were 1000 g=t. Conditioning time varied as 2, 3, 5,and 10 minutes. Results are given in Figure 5.

Figure 5 indicates that the conditioning time has an important role on separ-ation of PET-PVC mixture. The best results were obtained when the conditioningtime was chosen as 5 minutes. PET was floated with 91.9% content and 97% recoverywith DIB. Increasing conditioning time from 3 to 5 minutes increased the content ofPET from 86.2% to 91.9%. The highest PET content was obtained at 2 minutes con-ditioning time with using Triton XL-100N as 92.5%. Also, it is clearly seen that after2 minutes conditioning time, PVC particles start to float and increased PVC contentand floated product with using Triton XL-100N.

Effect of Flotation Time

To optimize flotation time, plastic mixture of �3.36þ 2mm in size was con-ditioned for 5 minutes for DIB and 2 minutes for Triton XL-100N separately,and then floated adding 1000 g=t MIBC. Flotation times were changed as 2, 3, 5,and 10 minutes and experimental results are given in Figure 6.

Figure 4 Concentration effect on PET flotation with Triton and DIB.

SEPARATION OF PET AND PVC 417

Dow

nloa

ded

by [

Ünz

ile Y

enia

l] a

t 00:

15 2

1 Ju

ne 2

013

If the results were examined in terms of content and recovery, the optimumflotation time was found as 3 minutes for DIB. At the end of 3 minutes flotationtime, a floated product was obtained with 91.9% content and 97% recovery. WhenTriton XL-100N was used, 84.2% PET recovery was obtained with a 92.5%content, at 2 minutes flotation time. DIB yielded better results in terms of recoveryat 3 minutes of flotation time. Increasing flotation time resulted in decrease of PETcontent.

Two-Staged Flotation Experiment in Optimum Conditions

As a common procedure in mineral processing, pre-concentrates of both pro-ducts (PET and PVC) can be re-treated in multiple stages. As is known, this causes a

Figure 5 Conditioning time effect.

Figure 6 Flotation time effect.

418 U. YENIAL ET AL.

Dow

nloa

ded

by [

Ünz

ile Y

enia

l] a

t 00:

15 2

1 Ju

ne 2

013

decrease in recovery and an increase in content. At selective purification experiments,Triton XL-100N and DIB were used to separate PET from PVC. The recovery of thePET particles was found to be 84.2% with using Triton XL-100N while the contentof the PET particles was 91.91% and recovery was 97% with Diethylene GlycolDibenzoate. When compared to Triton XL-100N, DIB provides more selectivityin flotation. Therefore, DIB was used in two-staged flotation experiments.

After optimization of all parameters, optimum conditions were found aspH 4, 1000 g=t DIB concentration, 5 minutes conditioning time and 3 minutes forflotation time. These parameters were fixed at both stages of the flotation experi-ments. The experimental results are given in Table 1. The separated PET andPVC particles are shown in Figure 7. As a result, a PET concentrate having 100%content was obtained with 84.3% recovery from floated product. In addition PVCconcentrate was obtained with 86.4% content and 100% recovery from sunkenproduct.

Table 1 Flotation test results after two stage flotation

Products Weight (%)

Content (%) Recovery (%)

PET PVC PET PVC

PET (Floated) 42.10 100.00 0.00 84.30 0.00

PVC (Sunken) 57.90 13.59 86.41 15.70 100.00

Feed 100.00 50.00 50.00 100.00 100.00

Figure 7 PET and PVC concentrates at the end of the experiments performed at optimum conditions

(color figure available online).

SEPARATION OF PET AND PVC 419

Dow

nloa

ded

by [

Ünz

ile Y

enia

l] a

t 00:

15 2

1 Ju

ne 2

013

CONCLUSIONS

It is possible to separate plastics from a mixture with the help of appropriatewetting agents and by adjusting experimental conditions to induce selective flotation.In experimental studies, the effects of the different plasticizers were investigatedapplying various parameters such as pH, concentration, conditioning time and flo-tation time. As both plastics (PET and PVC) are naturally floatable (hydrophobic),it is necessary to use an appropriate agent to achieve selective separation. It wasfound that the parameters determining the efficiency of separation were pH, typeand amount of plasticizers, and conditioning and flotation time. After treatmentwith plasticizers, it was possible to separate post-consumed PET and PVC by usingMIBC as a frother.

At the end of experiments, PET was separated from the mixture of PET andPVC at 100% content and 84.3% recovery rates with pH 4, conditioning time of5 minutes, flotation time of 3 minutes, DIB concentration of 1000 g=t and MIBCconcentration of 1000 g=t after two stages flotation.

This study shows that PET and PVC separation can be achieved successfullywithout any alkaline treatment.

ACKNOWLEDGMENTS

This research project has been supported by The Scientific and TechnicalResearch Council of Turkey (TUBITAK, Project No: 108M042) and the authorswould like to thank them for their financial support.

REFERENCES

Abbasi, M., Salarirad, M. M., and Ghasemi, I., 2010, ‘‘Selective separation of PVC fromPET=PVC mixture using flotation by tannic acid depressant.’’ Iranian Polymer Journal,19, pp. 483–489.

Bartalo, T., Agante, E., Carvalho, T., and Durao, F., 2004, ‘‘Froth flotation applied toseparation of PET from PS.’’ Proceedings of 10th International Mineral ProcessingSymposium, Cesme Turkey, pp. 269–276.

Burat, F., Guney, A., and Kangal, O., 2009, ‘‘Selective separation of virgin and post-consumed polymers (PET & PVC) by flotation.’ Waste Management, 29, pp. 1807–1813.

Carvalho, T., Durao, F., and Ferreira, C., 2010, ‘‘Separation of packaging plastics by frothflotation in a continuous pilot plant.’’ Waste Management, 30, pp. 2209–2215.

Carvalho, M. T., Ferreira, C., Santos, L. R., and Paiva, M. C., 2011, ‘‘Optimization offroth flotation procedure for poly(ethylene terephthalate) recycling industry.’’ PolymerEngineering and Science, 52, pp. 157–164.

Curlee, T. R. and Das, S., 1991, Plastic Wastes: Management, Control, Recycling, andDisposal, Park Ridge, NJ, USA: Noyes Data Co.

Dinger, P., 1992, ‘‘Automatic Microsorting for Mixed Plastics.’’ BioCycle, 33, pp. 79–80.Dodbiba, G., Haruki, N., Shibayama, A., Miyazaki, T., and Fujita, T., 2002, ‘‘Combina-

tion of sink–float separation and flotation technique for purification of shredded PET-bottlefrom PE or PP flakes.’’ International Journal of Mineral Processing, 65, pp. 11–29.

Drelich, J., Payne, T., Kim, J. H., Miller, J. D., and Kobler, R. W., 1999, ‘‘Purification ofpolyethylene terephthalate from polyvinyl chloride by froth flotation for the plastics(soft-drink bottle) recycling industry.’’ Separation Purification Technology, 15, pp. 9–17.

420 U. YENIAL ET AL.

Dow

nloa

ded

by [

Ünz

ile Y

enia

l] a

t 00:

15 2

1 Ju

ne 2

013

Ehrig, R. J., 1992, Plastics Engineering-Product and Process. Munich: Hanser Publishers, pp.303.

EPA. 2012, http://www.epa.gov/osw/conserve/materials/plastics.htmFraunholcz, N., 1997, ‘‘Plastics Flotation.’’ PhD thesis, Delft University of Technology, Delft,

The Netherlands.Fraunholcz, N., 2004, ‘‘Separation of waste plastics by froth flotation.’’ Minerals Engineering,

17, pp. 261–268.Hurd, D. J., 1997, ‘‘Best practices and industry standards in PET plastic recycling.’’ Washing-

ton State Department of Community, Trade, and Economic Development’s CleanWashington Center, http://www.napcor.com/pdf/Master.pdf

Kangal, O., 2010, ‘‘Selective flotation technique for separation of PET and HDPE usedin drinking water bottles.’’ Mineral Processing and Extractive Metallurgy Review, 31,pp. 214–223.

Le Guern, C., Conil, P., and Houot, R., 2000, ‘‘Role of calcium ions in the mechanism ofaction of a lignosulphonate used to modify the wettability of plastics for their separationby flotation.’’ Minerals Engineering, 13, pp. 53–63.

Marques, G. A. and Tenorio, J. A. S., 2000, ‘‘Use of froth flotation to separate PVC=PETmixtures.’’ Waste Management, 20, pp. 265–269.

Mikofalvy, B. K. and Boo, H. K., 1992, ‘‘Technical aspects of vinyl recycling.’’ In EmergingTechnologies in Plastics Recycling, ACS Symp. Ser. (G. D. Andrews, and 17 P. M.Subramanian Eds.), 513, pp. 296–309.

Ozdilek, C., 2011, ‘‘The investigation of surface properties in selective separation of PET andPVC wastes.’’, Master Thesis, Istanbul Technical University, (In Turkish).

Ratzsch, M., Jacobasch, K. J., and Freitag, K. H., 1990, ‘‘Origin, characterization and tech-nological effects of interaction forces proceeding from polymer surfaces.’’ Advances inColloid Science, 31, pp. 225–314.

Rosato, D. V., Rosato, M. G., and Rosato, D. V., 2000, Concise Encyclopedia of Plastics.Dordrect, The Netherlands: Kluwer.

Siddique, R., Khatib, J., and Kaur, I., 2007, ‘‘Use of recycled plastic in concrete: A review.’’Waste Management, 28, pp. 1835–1852.

Shen, H., Forssberg, E., and Pugh, R. J., 2001, ‘‘Selective flotation separation of plastics byparticle control.’’ Resources, Conservation and Recycling, 33, pp. 37–50.

Shen, H., Forssberg, E., and Pugh, R. J., 2002b, ‘‘Selective flotation separation of plastics bychemical conditioning with methyl cellulose.’’ Resources, Conservation and Recycling, 35,pp. 229–241.

Shen, H., Pugh, R. J., and Forssberg, E., 2002a, ‘‘Floatability, selectivity and flotation separ-ation of plastics by using a surfactant.’’ Colloids and Surfaces A: Physicochemical andEngineering Aspects, 196, pp. 63–70.

Super, M. S., Enick, R. M., and Beckman, E. J., 1992, ‘‘Separation of thermoplastics bydensity using near-critical and supercritical carbon dioxide and sulfur hexafluoride.’’In Emerging Technologies in Plastics Recycling, ACS Symp. Ser., (G. D. Andrews, andP. M. Subramanian, Eds.), 513, pp. 172–185.

Takoungsakdakun, T. and Pongstabodee, S., 2007, ‘‘Separation of mixed post consumerPET-POM-PVC plastic waste using selective flotation.’’ Separation and PurificationTechnology, 54, pp. 248–252.

Vane, L. M. and Rodriguez, F., 1992, ‘‘Selected aspects of poly (ethylene terephthalate)solution behavior.’’ In Emerging Technologies in Plastics Recycling, ACS Symp. Ser.,(G. D. Andrews, and P. M. Subramanian Eds.), 513, pp. 147–162.

SEPARATION OF PET AND PVC 421

Dow

nloa

ded

by [

Ünz

ile Y

enia

l] a

t 00:

15 2

1 Ju

ne 2

013