The Yangtze-Hydro Project: a Chinese-German environmental program.

Water of good quality is one of the basic needs of human life. Worldwide, great efforts are being undertaken for an assured water supply. In this respect, one of the largest water technology projects worldwide is the Yangtze Three Gorges Dam in China. There is a need for extensive scientific and technical understanding of the challenges arising from this large hydrological engineering project. German and Chinese groups from various scientific fields are collaborating to provide knowledge for the sustainable management of the reservoir. In this project description, the Yangtze Three Gorges Dam Project, its goals and challenges, are described in brief, and the contributions of the German research projects are presented.

Synthesis and analytical follow-up of the mineralization of a new fluorosurfactant prototype.

Fluorinated surfactants have become essential in numerous technical applications due to their unparalleled effectiveness and efficiency. The environmental persistence of the non-biodegradable perfluorinated alkyl moiety has become a matter of concern. Therefore, it was searched for new molecules with chemically stable fluorinated end groups which can be microbially transformed into labile fluorinated substances. One prototype substance, 10-(trifluoromethoxy)decane-1-sulfonate, has shown biomineralization. Monitoring the formation of metabolites over time elucidated the mechanism of biotransformation. Analysis was performed utilizing liquid chromatography-single quadrupole mass spectrometry (LC-MS) and quadrupole-time of flight tandem mass spectrometry (QqTOF-MS). It was possible to distinguish between two major degradation pathways of the fluorinated alkylsulfonate derivative: (i) a desulfonation and subsequent oxidation and degradation of the alkyl chain being predominant and (ii) an insertion of oxygen with a subsequent cleavage and degradation of the molecule. The utilized trifluoromethoxy-endgroup resulted in instable trifluoromethanol after degradation of the alkyl chain, which led to a high degree of mineralization of the molecule.

Possible interferences of mercury sulfur compounds with ethylated and methylated mercury species using HPLC-ICP-MS.

The HPLC-ICP-MS coupling technique is able to separate and detect methyl, ethyl and inorganic mercury isotopes specifically. An identification of ethyl mercury(+) is not possible when the widely used sodium tetraethylborate derivatisation method in combination with GC-AFS/AAS or ICP-MS techniques is performed because it contains ethyl groups.An unidentified compound with the same retention time as ethyl mercury was found in the HPLC chromatograms of industrial sewage samples and humic-rich soils of microcosm experiments after applying water vapour distillation. We also observed such unidentified peaks in samples of heavily contaminated sites in Eastern Germany, separated by HPLC fractionation only. In the experiments described, different mercury sulfur adducts were synthesised and tested for their retention times in the HPLC-ICP-MS system. It was found that the compound CH(3)-S-Hg(+) showed the same retention time as the ethyl mercury standard. It is therefore possible that ethyl mercury detected in chromatography by comparison of the retention time could also be due to an adduct of a sulfur compound and a mercury species. CH(3)-S-Hg(+ )should be tested in other chromatographic mercury speciation methods for this effect. This work can also be regarded as a contribution to the discussion of artificially occurring methyl mercury in sediments during sample preparation.

A sensitive method for the determination of iodine containing diagnostic agents in aqueous matrices using LC-electrospray-tandem-MS detection.

Iodinated contrast media belong to the most frequently applied compounds in medicine. They exhibit a high polarity and are very persistent against metabolism by the organism and environmental degradation. A sensitive method for the determination of five iodinated contrast media in aqueous matrices is described. Solid phase extraction utilizing Isolute ENV+ material was used for sample enrichment. The contrast media were partially separated on a RP-C18 column, and detection was achieved using electrospray-tandem MS (API III plus and API 365) allowing the sensitive quantitation of these compounds down to the lower ng/L range. The recovery rates generally exceeded 70%, for spiked surface water as well as tap water. The analytes were detected in native samples such as municipal sewage treatment plant (STP) effluent, the river Rhine and even in tap water.

Behavior and occurrence of estrogens in municipal sewage treatment plants--I. Investigations in Germany, Canada and Brazil.

The developed method enables the quantification of estrogens in sewage samples down to 1 ng/l and in river water down to 0.5 ng/l. Mean recoveries of the analytes in ground water after SPE extraction, clean-up and derivatization generally exceeded 75%. The determined R.S.D. varied from 0 to 14% at a spiking level of 0.05 microgram/l. Even in the raw influent and the final effluent from municipal STPs the mean recoveries of estrogens were mostly above 70%. Using this method the behavior and occurrence of natural estrogens and synthetic contraceptives in municipal sewage treatment plants (STP) were investigated in German and Canadian facilities. In the sewage of a German municipal STP close to Frankfurt/Main 17 beta-estradiol and estrone were determined, with mean concentrations of 0.015 microgram/l and 0.027 microgram/l, respectively. In two investigated municipal STPs, 17 beta-estradiol and 16 alpha-hydroxyestrone were eliminated with a higher efficiency than 17 alpha-ethinylestradiol and estrone. In Canadian and German STP discharges estrone, 17 beta-estradiol, 17 alpha-ethinylestradiol and 16 alpha-hydroxyestrone were frequently detected within the lower ng/l-range. A maximum concentration was found for estrone with 70 ng/l. In 15 investigated German rivers and streams only estrone was present with a maximum concentration of 1.6 ng/l.

Polar drug residues in sewage and natural waters in the state of Rio de Janeiro, Brazil.

The drug residues of lipid regulators, anti-inflammatories and some drug metabolites have been detected in raw sewage, treated waste water and river water in the state of Rio de Janeiro, Brazil. These residues are mainly derived from humans via excretion. The median concentrations in the effluents of sewage treatment plants (STPs) of most drugs investigated in this study ranged from 0.1 to 1 microgram/l. The removal rates of individual drugs during passage through a Brazilian STP varied from 12 to 90%. As a consequence of the incomplete removal of these residues during passage through a STP, rivers were also found to be contaminated. Median concentrations ranged from between 0.02 and 0.04 microgram/l in river water, whereas the maximum values were observed to be up to 0.5 microgram/l.

Determination of carboplatinum and cisplatinum by interfacing HPLC with ICP-MS using ultrasonic nebulisation.

A novel HPLC technique has been developed for the determination of carboplatinum(II) and cisplatinum(II) which are used for chemotherapy. The compounds were separated by a HPLC column. The eluent was on-line nebulized into the nebuliser gas flow using ultrasonic nebulisation. The resulting aerosol was driven by the nebuliser gas stream through a 30-cm heating path, a 60-cm cooling path for desolvatisation and into the plasma of the ICP-MS. The detection was carried out on platinum mass 195Pt. Different RP C18 techniques were tested to obtain the best separation and detection results of the two platinum compounds. The solvent-generated anion exchanger method was selected as the method with the best handling and sensitivity. This technique allows a good separation of the two compounds within 3 min. The detection limits for carboplatinum and cisplatinum were 130 and 80 pg, respectively. The newly developed system has been applied to study the behaviour of the platinum species under different anion influences in aqueous solutions. These investigations are necessary for the future development of an extraction from environmental samples for the two compounds. In further experiments the distribution of the two platinum species, Na2Pt(II)Cl4 and the palladium species. Na2Pd(II)Cl4 between water/sediment, water/charcoal, sewage sludge/water and the distribution in the solution after iron flocculation were investigated to plan an extraction method for the platinum species from environmental matrices.

Estimation of mercury content in tailings of the gold mine area of Poconé, Mato Grosso, Brazil.

As in many other parts of the world, gold is produced in the surface mining region of Poconé, Mato Grosso, Brazil, using mercury. The goal of this investigation was to estimate the amount of mercury in certain tailings and to determine the area of the land that has been contaminated by the gold mining operations. Mercury concentrations from 2 to 495 ng/g (dw) were determined in the tailing materials. It was observed that only isolated sites were acting as central points of contamination. Using digital Landsat satellite data (The-matic Mapper) and aerial photos, the sites degraded by the mining were classified, and their total area was estimated to be 12.3 km(2) in the region of Poconé. It was estimated, that 4.9 km(2) were occupied by the contaminated tailings. The mean height of the pile slags was determined to be 4.5 m. From the experimentally calculated average density of the material in the tailings, 2.01 g/cm(3), the total mercury content in the piles of tailings was estimated to be 1600 ± 350 kg.

Determination of organic mercury species in soils by high-performance liquid chromatography with ultraviolet detection.

Reversed-phase high-performance liquid chromatography with ultraviolet detection was optimized for the simultaneous separation and quantification of nine organic mercury compounds: methyl-, ethyl-, phenyl-, methoxyethyl-, ethoxyethyl-, benzoic and tolylmercury, mersalylic acid and nitromersol. The nine compounds were successfully separated on octadecylsilane columns (200 x 3 mm i.d.) by gradient elution with a methanol-water mixture ranging from 30 to 50% v/v. The detection limits for the various compounds are in the range 7.0-95.1 micrograms dm-3. For the extraction of five organomercurials from spiked soils, eight different extraction solutions were tested to differentiate between the total content and the available/soluble fraction of the analytes. Ammonium acetate solutions (1 mol dm-3) and water proved to be suitable agents for the estimation of the available and soluble fractions of methyl-, ethyl-, benzoic, methoxyethyl- and ethoxyethylmercury. For the determination of the total content of methyl- and benzoic mercury in soils, solutions of potassium iodide (1 mol dm-3)-ascorbic acid (0.1 mol dm-3) and oxalic acid (1 mol dm-3) provided recoveries in the ranges 53-81%. None of the solutions tested is suitable for the extraction of ethyl-, methoxyethyl- and ethoxyethylmercury.

The adsorption of hexachlorobenzene on naturally occurring adsorbents in water.

To evaluate the distribution of hexachlorobenzene (HCB) between water and natural adsorbents, laboratory experiments were performed with 14C-labelled HCB, with quartz, kaolinite, illite, bentonite, peat, suspended particulate matter and activated sewage sludge as the natural adsorbents. HCB was bound mainly to organogenic adsorbents with distribution coefficients between 140 (for bentonite) and 28,000 (for activated sewage sludge). Desorption experiments showed that distilled water could remobilize up to 100% HCB from mineral adsorbents, but only 3% from activated sewage sludge. Using these values, basic parameters for the bioavailability of HCB in natural waters were estimated.