Limited Reversibility of Bioconcentration of Hydrophobic Organic Chemicals in Phytoplankton

Research output: Contribution to journalArticleAcademicpeer-review

15 Citations (Scopus)

Abstract

Aging, reversibility and desorption rates for the binding of hydrophobic chemicals (HOC) to phytoplankton cells have not been directly measured. Here the effect of bioconcentration time on subsequent desorption of hexachlorobenzene (HCB) and polychlorinated biphenyls (PCBs) was studied for the alga Monoraphidium minutum. Cell suspensions were exposed to HCB and PCBs spanning a range of logKow values of 5.7 to 8.2, for 0.13 to 14 d. Subsequently, reversibility and desorption rates were assessed by extracting the chemicals from the cells using infinite sink extractions with Tenax beads or Empore disks employed in the cell suspension. Uptake was biphasic with constant relative contributions of fast surface sorption. Desorption was biphasic too and fitted well to a first order two compartment model. Increasing exposure times resulted in increasing slowly desorbing chemical fractions and decreased desorption rates from these fractions. For the most hydrophobic PCBs, slowly desorbing fractions were >80-90%, whereas desorption half-lives from these fractions ranged up to 120 days. The slow desorption rates directly prove that bioconcentration to algae can be rate limited and imply that already after a few hours of exposure HOCs may become practically unavailable for repartitioning.
Original languageEnglish
Pages (from-to)7341-7348
JournalEnvironmental Science and Technology
Volume48
Issue number13
DOIs
Publication statusPublished - 2014

Keywords

  • granular activated carbon
  • selenastrum-capricornutum
  • polychlorinated biphenyl
  • kinetics
  • sediment
  • water
  • chlorobenzenes
  • desorption
  • sorption
  • fluxes

Fingerprint Dive into the research topics of 'Limited Reversibility of Bioconcentration of Hydrophobic Organic Chemicals in Phytoplankton'. Together they form a unique fingerprint.

  • Cite this