Major dissolved phase constituents

Large amounts of phthalic acid esters (PAEs) are leached from plastics dumped at municipal landfills. This leachate transports PAEs either adsorbed on particulate matter or in dissolved phase. Dissolved organic macromolecules, mainly humic-like substances, enhance the solubility of PAEs. In the biochemical environments of municipal landfills short chain PAEs can be degraded by base-catalyzed hydrolysis or by microorganisms which enzymatically split the side chains. However, there is no cleavage of the aromatic ring. Long chain PAEs like di-(2-ethylhexyl) phthalate are neither degraded abiotically nor by microorganisms. Hence, these PAEs can be leached and washed out of leaky landfills into the groundwater and thus continue to be a threat to the aquatic environment. Only a combined UV radiation/ozonation treatment is capable of fully destroying PAEs.

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Leaching Rate of Polychlorinated Biphenyls (PCBs) from Marine Paint Chips

Archives of Environmental Contamination and Toxicology ◽

10.1007/s00244-021-00868-6 ◽

2021 ◽

Author(s):

Allen D. Uhler ◽

Jeffery H. Hardenstine ◽

Deborah A. Edwards ◽

Guilherme R. Lotufo

Keyword(s):

Polychlorinated Biphenyls ◽

Surface Waters ◽

Leaching Rate ◽

Short Term ◽

Aroclor 1254 ◽

Maintenance And Repair ◽

Potential Source ◽

Vessel Bottom ◽

Dissolved Phase ◽

Over Time

AbstractPolychlorinated biphenyls (PCBs) were added to certain marine vessel bottom paints as a plasticizer to improve the adhesion and durability of the paint. The most common PCB formulation used to amend such paints was Aroclor 1254. Fugitive Aroclor-containing paint chips generated from vessel maintenance and repair operations represent a potential source of PCB contamination to sediments. Limited published studies indicate that Aroclor-containing paint is largely inert and exhibits low PCB leaching into water; however, the rate and degree of leaching of PCBs from paint chips have not been directly studied. This laboratory-based study evaluated the rate and extent of leaching of PCBs from paint chips into freshwater. The results of this investigation demonstrate that the rate of PCB dissolution from paint chips decreased rapidly and exponentially over time. Based on this study, it is estimated that the rate of leaching of PCBs from paint chips would cease after approximately 3 years of exposure to water. When all leachable PCBs were exhausted, it is estimated that less than 1% of the mass of PCBs in the paint chips was amenable to dissolution. The results of this experiment suggest that Aroclor-containing paint chips found in sediments are likely short-term sources of dissolved-phase PCB to pore or surface waters and that the majority of the PCBs in paint chips remain in the paint matrix and unavailable for partitioning into water. Graphic Abstract

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Origin of Dissolved-phase Hyperpolarized 129Xe Signal in the Mouse Chest Based on Experimental Evidence from Extensive Magnetic Resonance Measurements

Magnetic Resonance in Medical Sciences ◽

10.2463/mrms.10.149 ◽

2011 ◽

Vol 10 (3) ◽

pp. 149-154 ◽

Cited By ~ 5

Author(s):

Michiko NARAZAKI ◽

Atsuomi KIMURA ◽

Tetsuya WAKAYAMA ◽

Hirohiko IMAI ◽

Hideaki FUJIWARA

Keyword(s):

Magnetic Resonance ◽

Experimental Evidence ◽

Hyperpolarized 129Xe ◽

Dissolved Phase

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Organic particles in a shallow sediment trap: Substantial loss to the dissolved phase

Limnology and Oceanography ◽

10.4319/lo.2001.46.3.0719 ◽

2001 ◽

Vol 46 (3) ◽

pp. 719-723 ◽

Cited By ~ 28

Author(s):

Paul Kähler ◽

Eduard Bauerfeind

Keyword(s):

Sediment Trap ◽

Substantial Loss ◽

Organic Particles ◽

Dissolved Phase

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Assessment of lung function in asthma and COPD using hyperpolarized129Xe chemical shift saturation recovery spectroscopy and dissolved-phase MRI

NMR in Biomedicine ◽

10.1002/nbm.3179 ◽

2014 ◽

Vol 27 (12) ◽

pp. 1490-1501 ◽

Cited By ~ 63

Author(s):

Kun Qing ◽

John P. Mugler ◽

Talissa A. Altes ◽

Yun Jiang ◽

Jaime F. Mata ◽

...

Keyword(s):

Chemical Shift ◽

Lung Function ◽

Saturation Recovery ◽

Dissolved Phase

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Rare earth element concentrations in dissolved and acid available particulate forms for eastern UK rivers

Hydrology and Earth System Sciences ◽

10.5194/hess-11-313-2007 ◽

2007 ◽

Vol 11 (1) ◽

pp. 313-327 ◽

Cited By ~ 11

Author(s):

C. Neal

Keyword(s):

Rare Earth ◽

Rare Earth Element ◽

Earth Element ◽

Flood Plain ◽

Strong Link ◽

Colloidal Form ◽

Linear Relationships ◽

Pollutant Sources ◽

Dissolved Phase ◽

Dissolved Form

Abstract. Variations in concentration of yttrium (Y), lanthanum (La), cerium (Ce), neodymium (Nd), samarium (Sm) and gadolinium (Gd) among rivers of eastern England and the border with Scotland are described in relation to the dissolved (<0.45 µM) fraction and acid-available particulate (AAP) fractions. The rivers cover a range of rural, agricultural and urban/industrial environments. Yttrium and the lanthanides show significant levels of both dissolved and acid-available particulate forms (typically about 40% in the dissolved form). For the dissolved phase, Y and the lanthanides are linearly correlated with each other and with iron: most of this dissolved component may be in a micro-particulate/colloidal form. The Y and lanthanide relationships show marked scatter and there are anomalously high La concentrations at times for the rivers Great Ouse, Thames and Wear that are probably linked to pollutant sources. For the Ouse, and especially for one of its tributaries, the Swale, relatively high Sm concentrations are probably associated with mineralisation within the catchment and contamination of the associated flood plain. For the AAP components, there are strong linear relationships with Y and the lanthanides across all the rivers. There is also a strong link between these AAP associated REE and AAP iron, although the scatter is greater and the industrial rivers have a lower lanthanide to iron ratio, probably due to iron-rich contaminants.

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