Mobility of trace metals in pore waters of two Central European peat bogs

Abstract. Halogens are strongly enriched in peat and peatlands and such they are one of their largest active terrestrial reservoir. The enrichment of halogens in peat is mainly attributed to the formation of organohalogens and climatically controlled humification processes. However, little is known about release of halogens from the peat substrate and the distribution of halogens in the peat pore water. In this study we have investigated the distribution of chlorine, bromine and iodine in pore water of three pristine peat bogs located in the Magellanic Moorlands, southern Chile. Peat pore waters were collected using a sipping technique, which allows in situ sampling down to a depth greater than 6m. Halogens and halogen species in pore water were determined by ion-chromatography (IC) (chlorine) and IC-ICP-MS (bromine and iodine). Results show that halogen concentrations in pore water are 15–30 times higher than in rainwater. Mean concentrations of chlorine, bromine and iodine in pore water were 7–15 mg l−1, 56–123 μg l−1, and 10–20 μg l−1, which correspond to mean proportions of 10–15%, 1–2.3% and 0.5–2.2% of total concentrations in peat, respectively. Organobromine and organoiodine were the predominant species in pore waters, whereas chlorine in pore water was mostly chloride. Advection and diffusion of halogens were found to be generally low and halogen concentrations appear to reflect release from the peat substrate. Release of bromine and iodine from peat depend on the degree of peat degradation, whereas this relationship is weak for chlorine. Relatively higher release of bromine and iodine was observed in less degraded peat sections, where the release of dissolved organic carbon (DOC) was also the most intensive. It has been concluded that the release of halogenated dissolved organic matter (DOM) is the predominant mechanism of iodine and bromine release from peat.

Download Full-text

The role of sediment-feeding oligochaeteTubifex on the availability of trace metals in sediment pore waters as determined by diffusive gradients in thin films (DGT)

Journal of Soils and Sediments ◽

10.1007/bf02987874 ◽

2002 ◽

Vol 2 (2) ◽

pp. 71-76 ◽

Cited By ~ 7

Author(s):

Jan-Willem M. Wegener ◽

Gerard A. van den Berg ◽

Gerard J. Stroomberg ◽

Martin J. M. van Velzen

Keyword(s):

Thin Films ◽

Trace Metals ◽

Pore Waters ◽

Diffusive Gradients

Download Full-text

Parasitoids (Hymenoptera) of leaf-spinning moths (Lepidoptera) feeding on Vaccinium uliginosum L. along an ecological gradient in central European peat bogs

Entomologica Fennica ◽

10.33338/ef.84535 ◽

2019 ◽

Vol 21 (4) ◽

pp. 243-253 ◽

Cited By ~ 1

Author(s):

Aurel Lozan ◽

Karel Spitzer ◽

Josef Jaroš ◽

Andrey Khalaim ◽

Maria Rizzo ◽

...

Keyword(s):

Peat Bogs ◽

Ecological Gradient ◽

Central European ◽

Vaccinium Uliginosum ◽

Habitat Adaptation

Parasitoids of leaf-spinning Lepidoptera associated with two isolated central European peat bogs were investigated. Five families of parasitoid Hymenoptera (Braconidae, lchneumonidae, Eulophidae, Pteromalidae and Encyrtidae) were recorded. Three categories were recognised: (1) primary parasitoids, (2) facultative hyperparasitoids and (3) obligatory hyperparasitoids. Ten species of Braconidae, five species and seven marked morphospecies among lchneumonidae, and three species of Chalcidoidea were identified. Despite of some niche-specific (but less host-specific) parasitoids, all these hymenopterans are likely to be generalists and none of them were confirmed to be habitat and/or host specialists. Unlike their eurytopic (opportunistic tyrphoneutral) parasitoids, the Lepidoptera hosts associated with peat bogs are partially highly stenotopic (tyrphobionts and tyrphophiles). The occurrence of parasitoids compared to their potential hosts was structured along an ecological (mesoclimatic) gradient, so most parasitoids were recorded from margins while stenotopic (narrow habitat adaptation) moths were mostly distributed near the centre of the bog habitat.

Download Full-text

Pore-water extraction from the unsaturated and saturated zones

Canadian Journal of Earth Sciences ◽

10.1139/cjes-2012-0165 ◽

2013 ◽

Vol 50 (10) ◽

pp. 1051-1058 ◽

Cited By ~ 8

Author(s):

Michael C. Moncur ◽

David W. Blowes ◽

Carol J. Ptacek

Keyword(s):

Pore Water ◽

Unsaturated Soils ◽

Metal Speciation ◽

Peat Bogs ◽

Immiscible Fluid ◽

Oxidation Reactions ◽

Pore Waters ◽

Oil Sand ◽

Fluid Displacement ◽

Water Volumes

A simple, inexpensive method for extracting pore water from unsaturated soils, which uses a combination of immiscible fluid displacement, suction, and mechanical compression, is described. This method uses a squeezing chamber to contain the unsaturated sediments in aluminum core tubing to prevent exposure of the sediments and pore water to atmospheric O2 and subsequent oxidation reactions. Geochemical artifacts resulting from high-compression squeezing are prevented by maintaining the pressure applied during the squeezing at a minimum. Comparison of squeezed profiles with field measured profiles of pH, Eh (oxidation–reduction potential), alkalinity, and metal speciation indicates good agreement between these parameters using this method. Depending on the water content of the sediments, a range of water volumes (several millilitres to excess of 100 mL) can be extracted from a single core section 7.6 cm in diameter by 20 cm long. Pore water was produced immediately from sediments at near-saturated conditions, whereas several hours were required to obtain pore water from sediment with low moisture contents. Pore water was extracted from unsaturated sediments with as little as 6% volumetric moisture content. The squeezing technique provided water samples from both unsaturated and saturated sediments ranging from silt- to sand-sized particles. The method was applied successfully to collect pore waters from unsaturated sediments in neutral and acidic mine tailings; processed sands from oil sand operations, septic beds, agriculturally impacted sediments; and saturated soils from peat bogs, from wetlands, and at groundwater–surface interfaces.

Download Full-text