Otoliths of black bream (Acanthopagrus butcheri) collected from the Swan River Estuary were analysed by Laser Ablation Inductively Coupled Plasma Mass Spectrometry (LA-ICP-MS) to measure concentrations of 14 trace metals. Trace metal concentrations in the otoliths may be related to the environmental exposure history of fish to contamination. The following metal isotopes were investigated: aluminium (²⁷Al), calcium (⁴⁴Ca), manganese (⁵⁵Mn), iron (⁵⁷Fe), copper (⁶⁵Cu), zinc (⁶⁶Zn), strontium (⁸⁸Sr), cadmium (¹¹¹Cd), tin (¹²⁰Sn), barium (¹³⁸Ba), mercury (²⁰²Hg), lead (²⁰⁸Pb) and the metalloids arsenic (⁷⁵As, ⁷⁷As) and selenium (⁸²Se). Significant differences in otolith trace metal composition were found between sampling sites. Lead and ⁵⁷Fe were consistently lower in downstream fish relative to upstream fish, while ⁸⁸Sr varied with the salinity gradient in the urban estuary. Lead and ⁵⁷Fe followed similar patterns within the otoliths, and appeared to provide the best discriminatory power for relating otolith metal concentration to the environmental history of the fish.

The selectivity and uptake capacity of horticultural peat available in Romania was evaluated with respect to the removal of Cd(II), Cr(VI) and Pb(II) ions from aqueous solution. The kinetics, sorption capacities, selectivity and pH dependence of sorption were determined. The influence of metal concentration in solution is discussed in the terms of Langmuir and Freundlich isotherm and constants. Sorption capacities increased with increasing metal concentration in solution. For solutions containing 300 mg/l of metal, the observed uptake capacities were 20 mg Cd(II)/g peat, 15 mg Cr(VI)/g peat and 30 mg Pb(II)/g peat. The study proved that horticultural peat is a suitable material for the removal of the studied heavy metal ions from aqueous solutions, achieving removal efficiencies higher than 90%, and could be considered as a potential material for treating effluent polluted with Cd(II), Cr(VI) and Pb(II) ions.

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.

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.

Interdisciplinary studies on aquatic environments and cross-validation of laboratory vs. field results will likely increase the need for simultaneous use of large- and small-scale ultrafiltration systems. In this study, a comparison of two ultrafiltration systems differing in scale (PrepScale and PelliconXL, Millipore; membrane areas 0.54 m² and 0.005 m², respectively), was made for the cut-offs 3 and 300 kDa. Large systems are useful for their high permeate throughput, while small systems are necessary when the amount of sample is limited. The ability of PrepScale and PelliconXL systems to provide comparable results for organic carbon fractionation was studied for polysaccharide solutions and natural freshwaters. In the latter, the colloidal proportions of different trace metals (V, Cr, Mn, Co, Ni, Cu, Sb, and U) were also determined. Although the colloidal proportions obtained with PelliconXL 3 kDa were sometimes slightly higher than with PrepScale 3 kDa (principally for DOC and U in natural waters), Mann-Whitney statistical test showed no significant difference in the overall fractionation properties of the two systems. Our observations show that reaching high concentration factors lead to a strong modification of colloids size distribution in the range 50-2,000 nm and thus low concentration factors are preferable to preserve the colloid integrity.

Regulators need a reliable, precise and easy to use tool for predicting the occurrence of pesticides in drain water and catchments in agricultural areas. Occurrence depends on a wide range of substance and site specific factors and this study presents a simple model built on the results from simulations of a detailed model system that does not neglect or omit any of these factors. A drainage dominated sub-catchment (0.03 km²) of the Lillebaek catchment (4.4 km²) on Funen, Denmark, represented by the catchment model MIKE SHE is considered. Detailed analyses have been made with respect to geological and hydrodynamic conditions as well as measurements of pesticide concentrations in ground and surface waters. Maximum concentrations in drain water, the time for reaching this concentration and the time interval for exceeding the limit value have been derived empirically from MIKE SHE simulations using degradation rates and sorption coefficients values for 37 pesticides included in the Danish PATE database. The relatively hydrophilic bentazon and hydrophobic pendimethalin are used as model pesticides for illustration. A simple tool applicable for a wide range of pesticides has thus been designed based on detailed analyses of a limited number of pesticides. The user requirements are degradation rates, sorption coefficients, application rates and regulatory limit values for the pesticides of interest.

Urban stormwater can be treated by infiltration at the source using systems like permeable paving. A critical component of such a system is the filtration media. Laboratory experiments were conducted using columns and boxes to evaluate the sediment retention efficiencies of different filtration media--crushed Greywacke, Greywacke mixed with 10% sand, and layered Greywacke and sand-Greywacke mix. Sediments of 0.001-6 mm were applied at concentrations of 460-4,200 mg/l along with water at flow rates of 100-900 ml/min. All columns showed between 96 and 91% sediment retention efficiency for single dry sediment applications, with lowered sediment retentions at higher flow rates. Decreasing the sediment loading, applying particles of <38 μm size, and suspending the particles in inflow as opposed to directly applying sediments to the column surface gave lower sediment retention efficiencies of 55 to 89%. Sediment retention primarily occurred in the top 20 mm of all columns and the 50th percentile value of retained sediments was 100-300 μm. The box tests showed little effect of flow and sediment loading on particle retention, with the tests showing an average retention of 93%. Similar to the column tests, the box tests showed lower sediment retention (84 to 88%) for <38 μm sediments and greater retention (approximately 95%) for larger sediments.

Plant toxicity and chemical removal tests were conducted to investigate the remediation ability of grasses with respect to volatile organic contaminants (VOCs) in contaminated soil and air. Eastern gamagrass (Tripsacum dactyloides) and annual ryegrass (Lolium rigidum) were exposed to artificially contaminated soil or air containing a mixture of 1,1,1-trichloroethane (TCA), trichloroethylene (TCE), and tetrachloroethylene (PCE) under controlled laboratory conditions. The results showed that the grasses are more severely affected in hydroponics than potted soil contaminated with a mixture of these contaminants. It was observed from the results that more contaminants were detected in the shoot and root of plants grown in a closed system with contaminated air than in an open system with contaminated soil. It is suggested from the results that grasses can be used for purification of VOCs from contaminated air especially in a closed system, but the purification effects are likely to be low. The results also suggested that the concentration level of VOCs in shoot, root, and soil could be used as contamination indicator at contaminated sites.

Advanced oxidation processes (AOPs) are among the most efficient methods for wastewater treatment. To achieve the degradation of persistent organic pollutants (POPs), AOPs have been developed that employ Fenton reactions promoted by ultrasound (US) or microwaves (MW). Integrated methods combining AOPs with biological treatments are also of great interest. The present paper describes such an integrated approach for the decontamination of water from nonylphenol (NP), a common pollutant that accumulates in aquatic organisms and is quite resistant to biodegradation. Polluted water (containing 1,000 ppm of NP) was sequentially subjected to a sonochemical Fenton reaction and biosorption by the filamentous fungus Paecilomyces lilacinus. Although these methods can be used separately, the sequential approach proved more advantageous. In 1 h the sonochemical oxidation, carried out in a 300 kHz US-reactor equipped with a cooling system, halved NP content in polluted water, as determined by GC-MS analysis. The water was then inoculated with pure cultures of the fungus, whose mycelial biomass further reduced NP content in 7 days. Thus an initial NP concentration of 1,000 ppm was reduced approximately by 90%.

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.