The chemical composition of precipitation in the city of Mersin on the Mediterranean coast of Turkey has been studied. Spatial and temporal variability of rainwater constituents have been determined from samples collected at two central and two suburban stations for the December 2003-May 2005 period. A total of 246 samples covering all precipitation events were analyzed to determine pH, conductivity, as well as major anion (Cl-, [graphic removed] , [graphic removed] ); major cation (H⁺, Na⁺, K⁺, Ca²⁺, Mg²⁺, [graphic removed] ) and formaldehyde (HCHO) concentrations. The pH varied within a range of 4.8-8.5, with only 8 out of 246 samples being acidic (pH < 5.6), and the remaining highly alkaline samples being neutralized by either [graphic removed] in rainwater, or by CaCO₃ resulting from wet deposition of atmospheric dust. The volume weighted mean ΣAnion/ΣCation ratio was 0.49. The equivalent concentration of major ionic species followed the order: [graphic removed] . Formaldehyde concentrations varied in the range of 0.01-17.9 μM, and was found to be dependent on precipitation volume. Relatively higher [graphic removed] , [graphic removed] , [graphic removed] and HCHO concentrations, mainly of anthropogenic origin, measured near the city center suggest increased pollution from local anthropogenic sources, e.g., residential heating, industrial and/or traffic emissions. In general, the results of this study suggest local precipitation chemistry is more strongly influenced by natural (mineral dust and marine) sources compared to anthropogenic ones.

In Europe more than 2,500 lysimeters operated by research institutes and industry (Lanthaler 2005). Originally lysimeters were built for investigations of soil water and solutes, nutrient leaching and pesticide degradation (see e.g. Winton and Weber 1996). Currently lysimeters additionally used as a tool for investigations on biological processes, and structural changes of plants, including root distribution, and enzyme activities etc. (see e.g. Dizer et al. 2002; Schloter et al. 2005).

Spectroscopic (XRD, XPS, ICP-MS and AAS) and microscopic (ESEM) techniques have been used in order to study the chemical effects with emphasis on mercury speciation, during thermal treatment of a mercury contaminated soil. In the untreated soil, mercury was found concentrated in spherical particles, which were successively broken down upon thermal treatment. Hg⁰ and inorganic mercury compounds (presumably HgO(s) and HgSO₄(s)) could be detected. No (CH₃)₂Hg and only traces of CH₃Hg⁺ could be found. The dependence on temperature and heating time indicated that the evaporation of mercury from the soil was partly controlled by diffusion mechanisms. Mercury volatilized in two separate stages during heating; initial elemental vaporization, and subsequent volatilization of the oxide or sulfate phase at higher temperatures (>230°C). By thermal treatment at 470°C and 20 min, a removal of >99% of the mercury could be achieved.

This paper deals with field measurements and hydraulic, oxygen transport and geochemical speciation modeling undertaken to evaluate the performance of a sand-bentonite test cover overlying a 20% sloping waste rock platform. A pit run (gravelly sand) layer protected the sand-bentonite layer. The study site was the Whistle Mine near Capreol, Ontario, Canada. The purpose of the study was to evaluate a number of test covers and select a final cover for the decommissioning of 7 million tonnes of acid-generating waste rock at the site. The sand-bentonite test plot and a control plot consisting of waste rock without cover were monitored over 3 years for water content, suction, soil temperature, gaseous oxygen concentrations, and water percolation. Air temperature, rainfall, snow pack and potential evaporation were also monitored. Finite element modeling showed very good agreement between modeled and measured cumulative precipitation, daily potential evaporation and cumulative evaporation, and to a lesser extent, the cumulative water percolation through the test cover. Due to construction difficulties in the field, the back of the waste rock platform was not covered with the test cover. This resulted in oxygen ingress from the back side of the waste rock. Oxygen transport modeling showed that if the entire waste rock pile had been covered, the daily oxygen flux would have been reduced by 90% to only 0.003 g/m²/day. Such low oxygen flux would minimize sulphide oxidation and hence acid generation in the waste rock. Aqueous equilibrium speciation modeling suggested that the concentrations of sulphate [graphic removed] , iron (Fe), and aluminum (Al) in percolate water in contact with waste rock were controlled by secondary minerals such as gypsum, alunite, and ferrihydrite.

In this paper a three-step procedure is proposed to deal with ecological data, usually very complex in their treatment. The three steps – exploratory, confirmatory, and modelling phases – reflect the different methodological approaches necessary in each phase of the study. To illustrate the methodology, a case study is proposed, concerning the suitability of plants as pollution bioindicators. Samples of differently aged Pinus pinea L. needles were collected throughout 1 year in three different locations, whose human disturbance was known to be different. In the samples some morphological and functional parameters were measured, whose relation with the stress was already known. The exploratory analysis suggested pollution with human origin, the needle’s age, and the environmental conditions as the main factors of influence of damage. The confirmatory analysis confirmed both site and age as main factors and occasionally the sampling date. On this basis, some models were estimated separately for each site: models that best described the damage as function of age resulted non-linear and some of them with seasonal fluctuations. As a result, whereas the models described well enough the pollution temporal variation, the difference of pollution in the sites was best described by the different values of the models parameters in the different sites. In short, different pollution conditions are described better by the damage trend than by the individual measures. The three-step procedure resulted of high utility in outlining the most interesting relations to investigate through the modelling, the opportunity to model the indicators variation along time separately for each site, and to introduce the seasonal variation in some models.

Several lysimeter scenarios and approaches exist to study the fate of agro-chemicals or contaminants from deposition in soil columns. In many systems just transport and leaching of the parent compound is followed, in some systems the leaching and transport of the metabolites is investigated as well. In more sophisticated lysimeter systems the volatilization and also the mineralization of the applied chemicals can be additionally monitored. Depending on the lysimeter system used and on the fact whether the applied chemicals are ¹⁴C-labeled or not, different results and various interpretations of the results might be achieved. Different lysimeter systems are described in this paper and a real dataset of a specific lysimeter experiment was transferred and evaluated in a virtual approach in the different lysimeter systems in order to show the advantages and disadvantages of the various systems.

A recently designed two-chamber-lysimeter-test-system allows the detailed investigation of degradation, transport and transfer processes of ¹⁴C-labeled substances in soil-plant-atmosphere-systems under outdoor conditions. With this test system it is feasible to distinguish between ¹⁴C-emissions from soil surfaces and ¹⁴C-emissions from plant surfaces in soil monoliths under real environmental conditions. Special soil humidity sensors allow the measurement of soil water content near to the soil surface, in 1 and 5 cm depth. The behavior of organic chemicals can be followed for a whole vegetation period and a mass balance for the applied chemical can be established. Some selected results of the herbicides isoproturon and glyphosate - using the two-chamber-lysimeter-test-system - are presented to demonstrate its applicability for the identification and quantification of the processes that govern pesticide behavior in soil-plant-systems. Mineralization of ¹⁴C-isoproturon was very different in four different soils; the mineralization capacity of the soils ranged from 2 to 60%. Leaching of isoproturon in general was very low, but depending on the soil type and environmental conditions isoproturon and its metabolites could be leached via preferential flow, especially shortly after application. For the herbicide ¹⁴C-glyphosate no accumulation of residues in the soil and no leaching of the residues to deeper soil layers could be observed after three applications. Glyphosate was rapidly degraded to AMPA in the soil. Glyphosate and AMPA were accumulated in soy bean nodules.

Recent European environmental legislation (the Water Framework Directive, the Environmental Liability Directive, and the REACH Regulation) should provide better protection of terrestrial water bodies but their focus is on the more conspicuous pollutants, as opposed to the large number of xenobiotic micro-pollutants that are increasingly being detected in the urban water cycle. The development of Drinking Water Safety Plans (DWSPs), as promoted by the World Health Organization, utilises a proactive risk assessment--risk management approach that necessarily should include micro-pollutants, although currently in the UK micro-pollutants have largely been ignored. The generic assessment of the risks posed by micro-pollutants is proposed and will require a consensus on analytical screening methods, sampling points and frequencies, and a method for prioritising concern, and would enable DWSPs to take fuller account of the risks posed.

The paper describes a novel approach to reduce ammonia emissions from Concentrated Animal and Feeding Operations (CAFO) in general, and from poultry houses in particular. The approach is based on installing a dedicated air capturing system on the feeding infrastructure that draws air from close to the litter. Air at these locations has NH₃₍g₎ concentrations an order of magnitude higher than at the vents of the ventilation system. Moreover, while the dedicated waste air drawing system can work continuously, the operation of the ventilation system is intermittent and directed towards maintaining the birds climatically-comfort. The NH₃₍g₎ rich waste air is conveyed to an acidic (0 < pH < ~5) bubble column reactor in which ammonia is converted to [Formula: see text]. The reactor operates in a batch mode, starting at pH 0 (1 N HCl solution) and is switched to a new acidic absorption solution just before NH₃₍g₎ breakthrough occurs, at around pH 5. Experiments with a wide range of NH₃₍g₎ concentrations showed that the absorption efficiency is practically 100% throughout the process as long as the face velocity is below 4 cm/s. The advantages of the method include high absorption efficiency, lower NH₃₍g₎ concentrations in the vicinity of the birds, generation of a valuable product (a high concentration ammonia solution) and the separation between the ventilation and ammonia treatment systems. A small scale pilot operation conducted for 5 weeks in a broiler house showed the approach to be technically feasible. A larger scale pilot study is required for fine-tuned cost estimation.

The canopy budget model simulates the interaction of major ions within forest canopies based on throughfall and precipitation measurements. The model has been used for estimating dry deposition and canopy exchange fluxes in a wide range of forest ecosystems, but different approaches have been reported. We give an overview of model variations with respect to the time step, type of open-field precipitation data, and tracer ion, and discuss the strengths and weaknesses of different assumptions on ion exchange within forest canopies. To examine the effect of model assumptions on the calculated fluxes, nine approaches were applied to data from two deciduous forest plots located in regions with contrasting atmospheric deposition, i.e. a beech (Fagus sylvatica L.) plot in Belgium and a mixed sugar maple (Acer saccharum Marsh.) plot in Quebec.For both forest plots, a semi-annual time step in the model gave similar results as an annual time step. Na⁺ was found to be more suitable as a tracer ion in the filtering approach than Cl⁻ or [Formula: see text]. Using bulk instead of wet-only precipitation underestimated the potentially acidifying deposition. To compute canopy uptake of [Formula: see text] and H⁺, ion exchange with K⁺, Ca²⁺, and Mg²⁺ as well as simultaneous cation and anion leaching should be considered. Different equations to allocate [Formula: see text] vs H⁺ uptake had most effect on the estimated fluxes of the cation that was less important at a plot. More research is needed on the relative uptake efficiency of H⁺, [Formula: see text], and [Formula: see text] for varying tree species and environmental conditions.