Suggested protocol for collecting, handling and preparing peat cores and peat samples for physical, chemical, mineralogical and isotopic analyses

For detailed reconstructions of atmospheric metal deposition using peat cores from bogs, a comprehensive protocol for working with peat cores is proposed. The first step is to locate and determine suitable sampling sites in accordance with the principal goal of the study, the period of time of interest and the precision required. Using the state of the art procedures and field equipment, peat cores are collected in such a way as to provide high quality records for paleoenvironmental study. Pertinent field observations gathered during the fieldwork are recorded in a field report. Cores are kept frozen at -18 degree C until they can be prepared in the laboratory. Frozen peat cores are precisely cut into 1 cm slices using a stainless steel band saw with stainless steel blades. The outside edges of each slice are removed using a titanium knife to avoid any possible contamination which might have occurred during the sampling and handling stage. Each slice is split, with one-half kept frozen for future studies (archived), and the other half further subdivided for physical, chemical, and mineralogical analyses. Physical parameters such as ash and water contents, the bulk density and the degree of decomposition of the peat are determined using established methods. A subsample is dried overnight at 105 degree C in a drying oven and milled in a centrifugal mill with titanium sieve. Prior to any expensive and time consuming chemical procedures and analyses, the resulting powdered samples, after manual homogenisation, are measured for more than twenty-two major and trace elements using non-destructive X-Ray fluorescence (XRF) methods. This approach provides lots of valuable geochemical data which documents the natural geochemical processes which occur in the peat profiles and their possible effect on the trace metal profiles. The development, evaluation and use of peat cores from bogs as archives of high-resolution records of atmospheric deposition of mineral dust and trace elements have led to the development of many analytical procedures which now permit the measurement of a wide range of elements in peat samples such as lead and lead isotope ratios, mercury, arsenic, antimony, silver, molybdenum, thorium, uranium, rare earth elements. Radiometric methods (the carbon bomb pulse of (14)C, (210)Pb and conventional (14)C dating) are combined to allow reliable age-depth models to be reconstructed for each peat profile.     

Monitoring of the three organophosphate esters TBP,TCEP and TBEP in river water and ground water (Oder,Germany)

The behaviour of the three organophosphate esters tributyl phosphate (TBP), tris(2-chloroethyl)phosphate (TCEP) and tris(2-butoxyethyl)phosphate (TBEP) during infiltration of river water to ground water has been investigated. The monitoring site is the Oder River and the adjacent Oderbruch aquifer. From March 2000 to July 2001, 76 ground water samples from monitoring wells located close to the Oder River and nine river water samples were collected. Additionally, influent and effluent samples from local waste water treatment plants, one sample of rain water and samples of roof runoff were collected. All samples were analysed by solid-phase-extraction followed by gas chromatography/mass spectrometry. TBP, TCEP and TBEP were detected at mean values of 622 ng l(-1), 352 ng l(-1), and 2955 ng l(-1), respectively in municipal waste water effluents. This points to a major input of these compounds into the Oder River by municipal waste water discharge. The concentrations of TBP and TBEP decreased downstream the Oder River possibly due to aerobic degradation. TBP, TCEP and TBEP were detected in ground water influenced predominantly by bank-filtered water. This demonstrates a transport of organic compounds by river water infiltration to ground water. TBP, TCEP and TBEP were also detected in rain water precipitation, roof runoff and ground water predominantly influenced by rain water infiltration. This hints to an input of these compounds to ground water by dry and wet deposition after atmospheric transport. Organophosphate esters were also detected in parts of the aquifer at 21 m depth. This demonstrates low anaerobic degradation rates of TBP, TCEP and TBEP.     

Partitioning of mercury onto suspended sediments in estuaries

Radiochemical partitioning experiments using 203Hg have been undertaken with mixtures of river, seawater and sediment samples taken from three geochemically contrasting UK estuaries: the Plym, Beaulieu and Mersey. Species of dissolved Hg were determined using reversed-phase C18 chelating columns and particulate species were determined by sequential leaching with 1 M NH4OAc and 1 M HCl. Mercury had a high particle reactivity with partition coefficients, KDs, ranging from 10(4) to 5 x 10(5) ml g(-1), depending on salinity, the chemical composition of the end-member waters, and on the physico-chemical characteristics of the sediment. Dissolved organic matter present in the waters (humic substances and/or anthropogenic compounds) was found to be the main factor governing the forms of dissolved Hg and their reactivity. From the spiked 203Hg, up to 95% of the dissolved metal was retained on the C18 columns for the Mersey waters, whereas this fraction was < 60% in the Plym and Beaulieu waters. Quasi-irreversible adsorption of Hg onto particles from each estuary was observed over a time-scale of a few hours and < 20% of total particulate Hg was released by the sequential leach. In this paper, physico-chemical processes are proposed to explain the estuarine behaviour of Hg and the results are discussed in terms of Hg availability in estuarine systems.     

Comparative studies on the soil life in ecofarmed and conventionally farmed fields and grasslands of Austria

The soil fauna of ecofarmed and conventionally farmed fields and grasslands was investigated in various regions of Austria. The results obtained from the evaluation of a total of 13 paired sites are reviewed in this contribution: (1) many of the investigated soil zoological parameters do not differ statistically in ecofarmed and conventionally farmed fields and grasslands; (2) there are no striking differences in species composition and dominance structure of the protozoa, an important group of indicator organisms due to their delicate external membranes, their short generation time and their high contribution to energy flow and nutrient cycling; (3) all differences which can be guaranteed with an error probability of α = 10% or less invariably show higher biological activity in the ecofarmed plots. The soil physical and chemical investigations which accompanied the zoological studies on some sites indicate that the higher biological activity is caused by the higher humus content and the lower soil compaction. The organic matter content is significantly higher in the ecofarmed plots, whereas soil compaction is more pronounced under conventional cultivation; (4) conventional agriculture has a more detrimental effect on soil fauna in semi-arid regions without stockfarming than in atlantic regions with mixed husbandry. A short review of the literature shows our results to be consistent with those of other studies. It is increasingly evident that generalizations like ‘Conventional farming destroys life in the soil’ or ‘Ecofarming stimulates soil life’ are only partially supported by the available data. A far more comprehensive view taking into account especially climate, soil type and farm management is necessary. However, the discernible detrimental effects on the soil organisms caused by conventional farming call for serious consideration and ought to stimulate the development of soft agricultural technology and intensified soil biological research. Future research should include studies on productivity of soil animals under various management systems, the analysis of single factors (e.g. the special admixtures used in biodynamic farming) to elucidate causative mechanisms, and studies on the relationship between soil animals, crop production and sustained yield.     

New findings on the generation of waste and emissions, and a modified cleaner production assessment approach-illustrated by leather production

New findings on the causes of waste and emissions, which were obtained from analysing numerous material streams in various sectors of industry, are presented in this article. It describes the implications of these findings for the vision of clean production, for formulating environmental policy concerning cleaner production targets, for the opportunities to assess to what extent the cleaner production targets have been met, and for the cleaner production assessment. A modified cleaner production assessment approach is presented, and illustrated using leather production as an example. The consequent implications for the diffusion of cleaner production are discussed.