PMID- 17493796
OWN - NLM
STAT- MEDLINE
DCOM- 20080515
LR  - 20151119
IS  - 0956-053X (Print)
IS  - 0956-053X (Linking)
VI  - 28
IP  - 3
DP  - 2008
TI  - Combination of three-stage sink-float method and selective flotation technique 
      for separation of mixed post-consumer plastic waste.
PG  - 475-83
AB  - The aim of this research was to separate the different plastics of a mixed 
      post-consumer plastic waste by the combination of a three-stage sink-float method 
      and selective flotation. By using the three-stage sink-float method, six 
      mixed-plastic wastes, belonging to the 0.3-0.5 cm size class and including high 
      density polyethylene (HDPE), polypropylene (PP), polyvinylchloride (PVC), 
      polystyrene (PS), polyethylene terephthalate (PET) and 
      acrylonitrile-butadiene-styrene copolymers (ABS) were separated into two groups, 
      i.e., a low density plastic group (HDPE and PP) and a high density plastic group 
      (PET, PVC, PS and ABS) by tap water. Plastic whose density is less than that of 
      the medium solution floats to the surface, while the one whose density is greater 
      than that of the medium solution sinks to the bottom. The experimental results 
      elucidated that complete separation of HDPE from PP was achieved by the 
      three-stage sink-float method with 50% v/v ethyl alcohol. To succeed in the 
      separation of a PS/ABS mixture from a PET/PVC mixture by the three-stage 
      sink-float method, a 30% w/v calcium chloride solution was employed. To further 
      separate post-consumer PET/PVC and PS/ABS based on plastic type, selective 
      flotation was carried out. In order to succeed in selective flotation separation, 
      it is necessary to render hydrophilic the surface of one or more species while 
      the others are kept in a hydrophobic state. In flotation studies, the effects of 
      wetting agent, frother, pH of solution and electrolyte on separation were 
      determined. The selective flotation results showed that when using 500 mg l(-1) 
      calcium lignosulfonate, 0.01 ppm MIBC, and 0.1 mg l(-1) CaCl2 at pH 11, PET could 
      be separated from PVC. To separate ABS from PS, 200 mg l(-1) calcium 
      lignosulfonate and 0.1 mg l(-1) CaCl2 at pH 7 were used as a flotation solution. 
      Wettability of plastic increases when adding CaCl2 and corresponds to a decrease 
      in its contact angles and to a reduction in the recovery of plastic in the 
      floated product.
FAU - Pongstabodee, Sangobtip
AU  - Pongstabodee S
AD  - Department of Chemical Technology, Faculty of Science, Chulalongkorn University, 
      Bangkok 10330, Thailand. sangobtip@gmail.com
FAU - Kunachitpimol, Napatr
AU  - Kunachitpimol N
FAU - Damronglerd, Somsak
AU  - Damronglerd S
LA  - eng
PT  - Journal Article
PT  - Research Support, Non-U.S. Gov't
DEP - 20070509
PL  - United States
TA  - Waste Manag
JT  - Waste management (New York, N.Y.)
JID - 9884362
RN  - 0 (Electrolytes)
RN  - 0 (Plastics)
RN  - 0 (Waste Products)
RN  - 0 (Wetting Agents)
RN  - 33T2H9O73P (calcium lignosulfonate)
RN  - 9005-53-2 (Lignin)
SB  - IM
MH  - Conservation of Natural Resources/*methods
MH  - Electrolytes/chemistry
MH  - Household Articles
MH  - Hydrogen-Ion Concentration
MH  - Lignin/analogs & derivatives/chemistry
MH  - Plastics/*chemistry
MH  - Refuse Disposal/*methods
MH  - Waste Products
MH  - Wetting Agents/chemistry
EDAT- 2007/05/12 09:00
MHDA- 2008/05/16 09:00
CRDT- 2007/05/12 09:00
PHST- 2006/04/29 00:00 [received]
PHST- 2007/01/13 00:00 [revised]
PHST- 2007/03/05 00:00 [accepted]
PHST- 2007/05/12 09:00 [pubmed]
PHST- 2008/05/16 09:00 [medline]
PHST- 2007/05/12 09:00 [entrez]
AID - S0956-053X(07)00104-3 [pii]
AID - 10.1016/j.wasman.2007.03.005 [doi]
PST - ppublish
SO  - Waste Manag. 2008;28(3):475-83. doi: 10.1016/j.wasman.2007.03.005. Epub 2007 May 
      9.