Desorption modeling of hydrophobic organic chemicals from plastic sheets using experimentally determined diffusion coefficients in plastics,

Marine Pollution Bulletin,Volume 126, 2018, Pages 312-317, ISSN 0025-326X,

Abstract:

To evaluate rate of migration from plastic debris, desorption
of model hydrophobic organic chemicals (HOCs) from polyethylene
(PE)/polypropylene (PP) films to water was measured using PE/PP films
homogeneously loaded with the HOCs. The HOCs fractions remaining in the
PE/PP films were compared with those predicted using a model
characterized by the mass transfer Biot number. The experimental data
agreed with the model simulation, indicating that HOCs desorption from
plastic particles can generally be described by the model. For
hexachlorocyclohexanes with lower plastic-water partition coefficients,
desorption was dominated by diffusion in the plastic film, whereas
desorption of chlorinated benzenes with higher partition coefficients
was determined by diffusion in the aqueous boundary layer. Evaluation of
the fraction of HOCs remaining in plastic films with respect to film
thickness and desorption time showed that the partition coefficient
between plastic and water is the most important parameter influencing
the desorption half-life.

https://www.sciencedirect.com/science/article/pii/S0025326X1730989X/pdfft?md5=f5ebb209e983577bbc4953f1a01c24cc&pid=1-s2.0-S0025326X1730989X-main.pdf

https://doi.org/10.1016/j.marpolbul.2017.11.032.(http://www.sciencedirect.com/science/article/pii/S0025326X1730989X)

https://drive.google.com/open?id=1ykdsS5Rmh7N1AHkGbjxJuZTV5DCwDlp9

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Marine Pollution Bulletin, Volume 126, 2018, Pages 606-609, ISSN 0025-326X,

Abstract:

Microplastics and synthetic musks (SMs) are two typical organic pollutants in the marine environment. In this study, the
sorption of three SMs to microplastics in a simulated seawater environment was examined.
Tonalide (AHTN), musk xylene (MX), and musk ketone (MK) were the musks investigated, while polypropylene (PP) was
used as the microplastic. It was found that the equilibrium sorption time was about 10h and the adsorption kinetics model conformed
to a Lagergren adsorption model.
The adsorption capacity increased with decreasing particle size. Adsorption reached a peak at 25°C, and the adsorption capacity was not sensitive to the concentration of sodium chloride. There is a need for more research and monitoring of microplastics in the marine environment due to their strong ability to absorb organic pollutants.

 https://www.sciencedirect.com/science/article/pii/S0025326X17307609/pdfft?md5=1acc6084801711d8f16eeaa52e913c7c&pid=1-s2.0-S0025326X17307609-main.pdf
https://doi.org/10.1016/j.marpolbul.2017.09.025.(http://www.sciencedirect.com/science/article/pii/S0025326X17307609)

The post Sorption of three synthetic musks by microplastics appeared first on One Earth - One Ocean e. V..

Marine Pollution Bulletin, Volume 126, 2018, Pages 312-317, ISSN 0025-326X,

Abstract:

To evaluate rate of migration from plastic debris, desorption of model hydrophobic organic chemicals (HOCs) from polyethylene
(PE)/polypropylene (PP) films to water was measured using PE/PP films homogeneously loaded with the HOCs. The HOCs fractions remaining in the PE/PP films were compared with those predicted using a model characterized by the mass transfer Biot number. The experimental data agreed with the model simulation, indicating that HOCs desorption from plastic particles can generally be described by the model.
For hexachlorocyclohexanes with lower plastic-water partition coefficients, desorption was dominated by diffusion in the plastic film, whereas desorption of chlorinated benzenes with higher partition coefficients was determined by diffusion in the aqueous boundary layer.

Evaluation of the fraction of HOCs remaining in plastic films with respect to film thickness and desorption time showed that the partition coefficient between plastic and water is the most important parameter influencing the desorption half-life.

https://doi.org/10.1016/j.marpolbul.2017.11.032.(http://www.sciencedirect.com/science/article/pii/S0025326X1730989X)

https://www.sciencedirect.com/science/article/pii/S0025326X1730989X/pdfft?md5=f5ebb209e983577bbc4953f1a01c24cc&pid=1-s2.0-S0025326X1730989X-main.pdf

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http://www.plosone.org/article/info%3Adoi%2F10.1371%2Fjournal.pone.0085433

Rochman CM, Hentschel BT, Teh SJ (2014) Long-Term Sorption of Metals Is 
Similar among Plastic Types: Implications for Plastic Debris in Aquatic 
Environments. PLoS ONE 9(1): e85433. doi:10.1371/journal.pone.0085433

Abstract
Concerns regarding plastic debris and its ability to accumulate large 
concentrations of priority pollutants in the aquatic environment led us 
to quantify relationships between different types of mass-produced 
plastic and metals in seawater. At three locations in San Diego Bay, we 
measured the accumulation of nine targeted metals (aluminum, chromium, 
manganese, iron, cobalt, nickel, zinc, cadmium and lead) sampling at 1, 
3, 6, 9 and 12 months, to five plastic types: polyethylene terephthalate 
(PET), high-density polyethylene (HDPE), polyvinyl chloride (PVC), 
low-density polyethylene (LDPE), and polypropylene (PP). Accumulation 
patterns were not consistent over space and time, and in general all 
types of plastic tended to accumulate similar concentrations of metals. 
When we did observe significant differences among concentrations of 
metals at a single sampling period or location in San Diego Bay, we 
found that HDPE typically accumulated lesser concentrations of metals 
than the other four polymers. Furthermore, over the 12-month study 
period, concentrations of all metals increased over time, and chromium, 
manganese, cobalt, nickel, zinc and lead did not reach saturation on at 
least one plastic type during the entire 12-month exposure. This 
suggests that plastic debris may accumulate greater concentrations of 
metals the longer it remains at sea. Overall, our work shows that a 
complex mixture of metals, including those listed as priority pollutants 
by the US EPA (Cd, Ni, Zn and Pb), can be found on plastic debris 
composed of various plastic types.

http://www.plosone.org/article/fetchObject.action?uri=info%3Adoi%2F10.1371%2Fjournal.pone.0085433&representation=PDF

The post Long-Term Sorption of Metals Is Similar among Plastic Types: Implications for Plastic Debris in Aquatic Environments. appeared first on One Earth - One Ocean e. V..