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The influence of humin preparations obtained from low-moor peat by the mechanochemical method on the changes in the microflora number and hydrocarbon composition in oil-polluted soils was studied. The intense growth of the microorganisms in number especially in the oil-polluted soil was observed upon the application of humin acids (at a concentration of 0.005 wt %) extracted from mechanically processed peat. In this case, the content of the extracted bitumoids decreased down to 40 wt %. The soil microflora stimulated by the humin preparations was shown to have highly destructive oil-oxidizing activity reflected in the indices of the hydrocarbon biodegradation. The mechanochemical activation of peat allows raising the efficiency of extracting the humic acids and can be a reason for increasing the availability of their individual components and parts of molecules, including micro- and macroelements that are used by microbial cells as sources of nutrition and energy.
Biocide leaching was investigated for acrylate and vinyl acetate based coatings containing biocides either as liquid formulations or microcapsules. Laboratory and field tests indicate similar relations of results on carbendazim, diuron, terbutryn and OIT from different coatings in laboratory and field experiments. Emissions were higher in EN 16105 laboratory tests than from vertically installed test specimens exposed to weathering, and slower for microencapsulated biocides. Competing processes that cause losses of active substances can occur in both tests, but to a higher degree in field experiments. Emission curves related to runoff water were similar in repeated field experiments. Relative humidity, temperature and global radiation were identified as meteorological factors that affect leaching by complex interaction besides the amount of driving rain.
Biocide leaching was investigated for acrylate and vinyl acetate based coatings containing biocides either as liquid formulations or microcapsules. Laboratory and field tests indicate similar relations of results on carbendazim, diuron, terbutryn and OIT from different coatings in laboratory and field experiments. Emissions were higher in EN 16105 laboratory tests than from vertically installed test specimens exposed to weathering, and slower for microencapsulated biocides. Competing processes that cause losses of active substances can occur in both tests, but to a higher degree in field experiments. Emission curves related to runoff water were similar in repeated field experiments. Relative humidity, temperature and global radiation were identified as meteorological factors that affect leaching by complex interaction besides the amount of driving rain.
Leaching of biocides from construction products is currently a research topic receiving attention from the European regulation authorities (CEN/TC 351).
In this paper we have focused on the leaching behaviour of CBA (copper-borateazoles) treated Pinus sylvestris.
To better define the chemistry of the leaching phenomena, two leaching tests (a static equilibrium test and a dynamic surface leaching test) have been carried out on untreated and treated wood, which offered more information about how the leaching of biocides interferes with other substances released from the wood structure.
Eluates, in liquid and lyophilised form, were further analyzed by analytical methods.
Organic (tebuconazole) and inorganic (Cu, B) biocides were quantified and several organic compounds have been identified (e.g.
carboxylic acids, phenols, amines, etc.).
Also, the total amount of phenols and of carboxylic groups was determined.
Results on inorganic compounds are in accordance with previous studies made on treated wood.
Furthermore, organic carbon, tebuconazole and other organic compounds' behaviour was extensively investigated.
This study aims to complete existing leaching data and to help developing a chemical model for several biocides in wood, including Cu, B and tebuconazole.
Stormwater from urban areas can transport biocidally active substances and related transformation products from buildings into the environment. The occurrence of these substances in urban runoff depends on the availability of water, and on ultraviolet radiation exposure that causes photolytic reactions. In a systematic laboratory study, painted test specimens were exposed to either ultraviolet radiation, water contact, or a combination of both. Leaching of the biocidally active substances carbendazim, diuron, octylisothiazolinone, terbutryn, and selected transformation products of terbutryn and diuron were observed under various exposure conditions. Remaining concentrations of these substances in the paint were quantified. It was demonstrated that the distribution of active substances and transformation products in eluates and in the coatings themselves differs with exposure conditions. Strategies for environmental monitoring of biocide emissions need to consider the most relevant transformation products. However, environmental concentrations of biocidally active substances and transformation products depend on earlier exposure conditions. As a consequence, monitoring data cannot describe emission processes and predict expected leaching of biocidally active substances from buildings if the data are collected only occasionally.
This report supports the implementation of European regulations on biocidal products for the product types 7, 9 and 10. Emission of active substances from material preservatives into environmental compartments can occur due precipitation. Risk characterisations have to be based on estimations of environmental concentrations of target substances leached from material preservatives. Harmonised test procedures are required to predict environmental impact due to leaching. Seventeen treated articles, mainly paints, but also a textile, sealing tapes and sealing masses were investigated by intermittent contact to water to prove suitability of the proposed laboratory test procedure. Parameters that affect leaching of active substances were examined.
Further development of a semi-analytical model to describe laboratory leaching data revealed that the model can be improved if changes of the leachability of substances during the test are supposed and integrated. Six paints and a textile were exposed to weathering to compare results from laboratory and field experiments. Similarities between leaching processes in both test approaches were observed. Generally, emissions of active substances are considerably higher in laboratory tests than from vertically installed test specimens exposed to weathering. Competing processes that cause losses of active substances can occur in both tests, but to a higher degree in field experiments. In addition, the influence of meteorological parameters on leaching processes was investigated. Factors besides the amount of driving rain were identified that effect leaching processes by complex interaction. Relations between laboratory and field data were analysed, and the applicability of the semi-analytical model was tested for field data. Guidance documents for leaching tests under laboratory and field conditions were drafted and discussed with experts on EU Level workshop 3./4. July 2014, BAM, Berlin), and are included in this Report.
Column tests are a common tool to investigate the leaching behavior of contaminated soil and waste materials. In contrast to inorganic analytes, fewer studies with organic contaminants are available based on column tests. This paper is aimed at the question if soil materials contaminated with organic pollutants can be reliably investigated by column tests. Soils contaminated with TPH (total petrol hydrocarbons), PFC (perfluorinated surfactants) and the biocide tebuconazole were used for column percolation tests. Differences in the leaching behavior are mainly driven by partitioning behavior between organic carbon and water, which can be estimated from log KOW values and size and shape of molecules. PFC show higher release (10–50% for individual compounds) than pesticides (3.7–5.3%) and TPH (< 1%) at liquid to solid ratio of 4 l/kg. All eluate concentrations are low with maximum concentrations of 50 µg/l for PFC and 1–2 mg/l for pesticides and TPH. Despite this, the observed standard deviations are quite small suggesting good repeatability. In general the observed concentration trends are similar to that from lysimeter studies found in the literature and thus, it can be concluded that laboratory column experiments are a reliable tool for organic compounds with various physico-chemical properties.