Merck
  • Home
  • Search Results
  • Response of bacteria and meiofauna to iron oxide colloids in sediments of freshwater microcosms.

Response of bacteria and meiofauna to iron oxide colloids in sediments of freshwater microcosms.

Environmental toxicology and chemistry (2015-06-03)
Sebastian Höss, Béatrice Frank-Fahle, Tillmann Lueders, Walter Traunspurger
ABSTRACT

The use of colloidal iron oxide (FeOx) in the bioremediation of groundwater contamination implies its increasing release into the environment and requires an assessment of its ecotoxicological risk. Therefore, microcosm experiments were carried out to investigate the impact of ferrihydrite colloids on the bacterial and meiofaunal communities of pristine freshwater sediments. The effects of ferrihydrite colloids were compared with those of ferrihydrite macroaggregates to discriminate between colloid-specific and general FeOx impacts. The influence of ferrihydrite colloids on the toxicity of sediment-bound fluoranthene was also considered. At high concentrations (496 mg Fe kg(-1) sediment dry wt), ferrihydrite colloids had a significant, but transient impact on bacterial and meiofaunal communities. Although bacterial community composition specifically responded to ferrihydrite colloids, a more general FeOx effect was observed for meiofauna. Bacterial activity responded most sensitively (already at 55 mg Fe kg(-1) dry wt) without the potential of recovery. Ferrihydrite colloids did not influence the toxicity of sediment-bound fluoranthene. Significant correlations between bacterial activity and meiofaunal abundances were indicative of trophic interactions between bacteria and meiofauna and therefore of the contribution of indirect food web effects to the observed impacts. The results suggest that the application of ferrihydrite colloids for remediation purposes in the field poses no risk for benthic communities, given that, with the exception of generic bacterial activity, any negative effects on communities were reversible.

MATERIALS
Product Number
Brand
Product Description

Sigma-Aldrich
Acetone, suitable for HPLC, ≥99.9%
Sigma-Aldrich
3-Ethyl-2,4-pentanedione, mixture of tautomers, 98%
Sigma-Aldrich
Sodium hydroxide solution, BioUltra, for molecular biology, 10 M in H2O
Sigma-Aldrich
Sodium hydroxide, BioUltra, for luminescence, ≥98.0% (T), pellets
Sigma-Aldrich
Sodium hydroxide solution, 1.0 N, BioReagent, suitable for cell culture
Sigma-Aldrich
Sodium hydroxide, ultra dry, powder or crystals, 99.99% trace metals basis
Sigma-Aldrich
Sodium hydroxide, BioXtra, ≥98% (acidimetric), pellets (anhydrous)
Sigma-Aldrich
Sodium hydroxide, puriss., meets analytical specification of Ph. Eur., BP, NF, E524, 98-100.5%, pellets
Sigma-Aldrich
Sodium hydroxide solution, purum, ≥32%
Sigma-Aldrich
Sodium hydroxide, puriss. p.a., ACS reagent, reag. Ph. Eur., K ≤0.02%, ≥98%, pellets
Sigma-Aldrich
Sodium hydroxide, puriss. p.a., ACS reagent, K ≤0.02%, ≥98.0% (T), pellets
Sigma-Aldrich
Acetone, puriss., meets analytical specification of Ph. Eur., BP, NF, ≥99% (GC)
Sigma-Aldrich
Acetone, ACS reagent, ≥99.5%
Sigma-Aldrich
Sodium hydroxide, reagent grade, 97%, powder
Sigma-Aldrich
Sodium hydroxide, reagent grade, ≥98%, pellets (anhydrous)
Sigma-Aldrich
Sodium hydroxide, beads, 20-40 mesh, reagent grade, 97%
Sigma-Aldrich
Sodium hydroxide solution, 50% in H2O
Sigma-Aldrich
Acetone, puriss. p.a., ACS reagent, reag. ISO, reag. Ph. Eur., ≥99.5% (GC)
Sigma-Aldrich
Sodium hydroxide, ACS reagent, ≥97.0%, pellets
Sigma-Aldrich
Sodium hydroxide, pellets, semiconductor grade, 99.99% trace metals basis
Sigma-Aldrich
Sodium hydroxide, reagent grade, 97%, flakes
Sigma-Aldrich
Sodium hydroxide solution, 5.0 M
Sigma-Aldrich
Sodium hydroxide, anhydrous, free-flowing, Redi-Dri, reagent grade, ≥98%, pellets
Sigma-Aldrich
Fluoranthene, 98%
Sigma-Aldrich
Potassium hydroxide, ≥85% KOH basis, pellets, white
Supelco
Potassium hydroxide solution, volumetric, 8.0 M KOH (8.0N)
Sigma-Aldrich
Potassium hydroxide, free-flowing, Redi-Dri, ACS reagent, ≥85%, pellets
Sigma-Aldrich
Potassium hydroxide, puriss., meets analytical specification of Ph. Eur., BP, 85-100.5%, pellets
Sigma-Aldrich
Potassium hydroxide, technical, ≥85%, powder
Sigma-Aldrich
Potassium hydroxide, reagent grade, 90%, flakes