Joseph Tarradellas

Urban stormwater contamination by polychlorinated biphenyls (PCBs) and its importance for urban water systems in Switzerland

Like other persistent organic pollutants (POPs), polychlorinated biphenyls (PCBs) are still present in the environment despite their almost worldwide prohibition. A study was conducted over 1 year in Switzerland to analyze the source and load of PCBs in urban stormwater and their importance in urban water systems. The mean PCB concentrations of 89 rain events were determined in five different strictly separate drainage systems (three in Lausanne and two in Geneva). The mean concentrations of PCBs in stormwater ranged from values below the detection limit (0.11-0.24 ng/l) to 403 ng/l. A model for the wet and dry deposition of PCBs based on these results estimates that their concentration in rainwater has remained practically constant (35 ng/l) over a period of 12 years. A mass balance of Swiss levels estimates a total input load of PCBs in the urban water systems at 110-125 kg/year. The contribution of stormwater is 75-94 kg/year in combined sewer systems and 23-34 kg in separate sewer systems. This mass balance illustrates that a major part of the PCB load in the environment or in WWTP sludges originates from urban stormwater. This result was confirmed by a fingerprint of PCB congeners in stormwater, which showed a pattern identical to that found in sewage sludge in combined sewer systems.

Analysis of Acidic Drugs in Swiss Wastewaters

Five acidic drugs (clofibric acid, ibuprofen, ketoprofen, mefenamic acid and diclofenac) were chosen in order to determine their behavior in a sewage treatment plant (STP). An analytical method using solid phase extraction (SPE) and a gas chromatograph coupled with a mass spectrometer (GC-MS) was used. The results show that four pharmaceuticals (clofibric acid, ketoprofen, mefenamic acid and diclofenac) are not well removed by treatment in Swiss STPs. Maximum concentration in the effluent was determined for mefenamic acid up to 1.0 µg/L. This component seems to be relevant in Swiss STPs effluents and we can expect its presence in surface waters.

Trace determination of Tamoxifen and 5-Fluorouracil in hospital and urban wastewaters

Tamoxifen and 5-fluorouracil are widely used in cancer therapy. They are highly toxic (teratogenic, mutagenic, etc.), as are most of the anticancer drugs. Two methods were set up to analyse these drugs in wastewaters to evaluate the potential for environmental contamination by cytostatic agents. Liquid–liquid extraction followed by purification on OASIS® MCX cartridge and gas chromatography with mass spectrometry detection (GC-MS) was used for the analysis of tamoxifen. 5-Fluorouracil was extracted with an ENV+ (Isolute) cartridge (solid-phase extraction), derivatized with pentafluorobenzyl bromide (PFBBr) and detected by GC-MS. Both methods showed good recoveries (>70%), repeatability (RSD<10%) and limits of detection (LOD 6–15 ng/L). Wastewaters from a residential area, a hospital, and sewage-treatment plants (STPs) were analysed using the analytical methods developed in this study. Tamoxifen was detected in wastewaters of the hospital, residential area, and influent of STPs, but not in treated wastewaters. 5-Fluorouracil in all wastewaters was below the LOD of the analytical method.

Organotins in swiss lakes after their ban: assessment of water, sediment, and dreissena polymorpha contamination over a four-year period

The effect of a legal ban on antifouling paints containing organotin compounds (1988, to be fully enforced within two years) was studied in Swiss freshwater ecosystems. Between 1990 and 1993, organotins were monitored in water, sediment, and zebra mussel tissue (Dreissena polymorph) from four lakes (one marina and one natural reference site per lake). The analytical technique was a gas chromatography method using FPD detection after methylation or hexylation.In the studied marinas, no significant decrease in concentrations was detected in sediment and zebra mussel tissue; a reduction was measured in water. The levels observed are probably due to the continuing use of antifouling paints still containing organotins, and to a slow degradation in sediment. A survey conducted among boat owners of the studied marinas allowed us to estimate that an average 25% of boats were still protected by organotin-containing antifoulings one to two years after the new legislation. Zebra mussels, used as biomonitors, showed very high concentrations of tributyltin (up to 49 μg/g dry weight). No shell thickening or other growth effect was observed. In the reference sites, much lower levels were detected.

Degradation in soil and water and ecotoxicity of rimsulfuron and its metabolites

The degradation and ecotoxicity of sulfonylurea herbicide rimsulfuron and its major metabolites were examined in batch samples of an alluvial sandy loam and in freshwater. An HPLC-DAD method was adapted to simultaneously identify and quantify rimsulfuron and its metabolites, which was successfully validated by GC-MS analysis. In aqueous solutions, pure rimsulfuron was rapidly hydrolyzed into metabolite 1 (N-(4,6-dimethoxypyrimidin-2-yl)-N-(3-(ethylsulfonyl)-2-pyridinylurea)), which itself was transformed into the more stable metabolite 2 (N-((3-(ethylsulfonyl)-2-pyridinyl)-4,6-dimethoxy-2-pyrimidineamine)), with half-life (t(1/2)) values of 2 and 2.5 days, respectively. Hydrolysis was instantaneous under alkaline conditions (pH = 10). In aqueous suspensions of the alluvial soil (pH = 8), formulated rimsulfuron had a half-life of 7 days, whereas that of metabolite 1 was similar to that in water (about 3.5 days). The degradation of the two major metabolites was also studied in soil suspensions with the pure compounds at concentrations ranging from 1 to 10 mg l(-1). The half-life of metabolite 1 ranged from 3.9 to 5 days, close to the previous values. Metabolite 2 was more persistent and its degradation is strongly dependent on the initial concentration (C0): half-life values ranged from 8.1 to 55 days at 2-10 mg l(-1), respectively. These values are higher than those determined from the kinetics of metabolite 1 transformation into metabolite 2 (t(1/2) = 8-19 days). The ecotoxicity of the three chemicals was evaluated through their effect on Daphnia magna and Vibrio fischeri (Microtox bioassay). No effect was observed on D. magna with 24 and 48 h acute toxicity tests. Similarly, no toxic effect was observed with the Microtox test for the three chemicals in the range of concentrations tested that included the field application dose. Thus, being of low persistence and lacking acute toxicity, these chemicals present a low environmental risk. However, chronic effects should be studied in order to confirm the safety of rimsulfuron and its major metabolites.

Comparison of supercritical fluid extraction (SFE), Soxhlet and shaking methods for pendimethalin extraction from soils : effect of soil properties and water content

Keywords: Physique du sol Reference CECOTOX-ARTICLE-1998-003doi:10.1016/S0169-7722(98)00089-8View record in Web of Science Record created on 2005-07-15, modified on 2016-08-08

Organic pollutants in compost and digestate.

In Europe, 9.3 x 10(6) t(dry weight (dw)) of compost and digestate are produced per year. Most of this is applied to agricultural land, which can lead to considerable inputs of organic pollutants, such as polychlorinated biphenyls (PCB) and polycyclic aromatic hydrocarbons (PAH) to soil. This paper presents an inventory of the pollutant situation in source-separated composts, digestates and presswater in Switzerland by a detailed analysis of over 70 samples. PCB concentrations ( summation PCB 28, 52, 101, 118, 138, 153, 180) were significantly higher in urban (median: 30 microg kg(-1)dw, n = 52) than in rural samples (median: 14 microg kg(-1)dw, n = 16). Together with low concentrations in general, this points to aerial deposition on compost input material as the major contamination pathway. Enantiomeric fractions of atropisometric PCB were close to racemic. Median PAH concentration was 3010 microg kg(-1)dw( summation 15PAH, n = 69), and one quarter of the samples exhibited concentrations above the relevant Swiss guide value for compost (4000 microg kg(-1)dw). The levels were influenced by the treatment process (digestate > compost), the season of input material collection (spring-summer > winter > autumn), the particle size (coarse-grained > fine-grained), and maturity (mature > less mature). The main source of PAH in compost was pyrogenic, probably influenced mainly by liquid fossil fuel combustion and some asphalt abrasion, as suggested by multiple linear regression. This study, together with a companion paper reporting on other organic contaminates including emerging compound classes, provides a starting point for a better risk-benefit estimation of the application of compost and digestate to agricultural soil in Switzerland.

Optimised accelerated solvent extraction of PCBs and PAHs from compost

This study is the first thorough method optimisation for accelerated solvent extraction (ASE) of polychlorinated biphenyls (PCBs) and polycyclic aromatic hydrocarbons (PAHs) from chemically dried compost. For PCBs, optimised solvent composition, temperature, pressure, number of static cycles, duration, and flush volume were as follows: toluene/acetone 1 : 3 (v/v), 120°C, 2000 psi, 3 × 5 min, and 50%, respectively. Limits of quantification and method precision were between 0.16 and 2.46 µg kg−1 dw and 6–17% respectively for individual PCBs. Absolute recoveries of isotope-labelled extraction standards used for each of the analytes ranged from 65 to 105% and relative recoveries were between 85 and 99%. The method proofed to be robust and was successfully applied to different compost samples. The optimisation of PAHs extraction was performed and resulted in the following conditions: solvent: hexane/acetone 1/3 (v:v), temperature: 140°C, pressure: 1500 psi, extraction time: 3 × 5 min, and 50% flush volume. Limits of detection and method precision for individual PAHs were between 1.1 and 37.2 µg kg−1 dw and 12–34% respectively. Absolute and relative recoveries ranged from 24 to 68% and from 85 to 99%, respectively. Optimal extraction conditions for PAHs were more difficult to determine due to the inhomogeneous distribution of PAHs in samples. However, the method appeared to be feasible and suggestions for further improvements are presented.

Soil contamination by some organic micropollutants related to sewage sludge spreading

The aim of the present publication is to give some information on soil contamination by 4 different micropollutant classes due to sewage sludge spreading. The soil under research shows an accumulation of light molecular weight PAHs and PCBs, DEHP and 4-NP just after spreading, but one month later the concentration of these micropollutant groups fall to the concentration detected just before the sludge spreading. As far as the soil concentration is concerned, only PAHs and PCBs are precipitation dependent. Some test plots, enriched during 10 years with fertilisers, pig-dung or sewage sludges show only an increase of the PAH concentrations of the plots amended with sludges. In the same way, the sewage sludge is chiefly responsible for the increase of PCBs in the soils, but pig-dung seems to contain quantities of these micropollutants which have to be taken into consideration.

Earthworm contamination by PCBs and heavy metals

Abstract A comparison is made of soil and earthworm contamination by PCBs and heavy metals between a nature reserve and two sites conditioned by the addition of sewage sludge and compost. The tissues and gut content of the earthworms shows a higher PCB concentration than that of the surrounding soil and also a difference in the fingerprint of some single PCB compounds. Earthworms display a selective accumulation of cadmium and zinc in their tissues and gut content.