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Degradation of Congo Red (CR) dye in aqueous solutions was investigated by means of photocatalysis of TiO2 which was hydrothermally synthesized at 200 degrees C in 2 h, in anatase phase with 8 nm crystallite size. Efficiency of TiO2 in photocatalytic degradation under visible irradiation was studied by investigating the effects of amount of TiO2, irradiation time, initial CR concentration and pH. It was found that complete decolorization is achieved within 30 min of irradiation. Effects of nitrate and sulphate ions and humic acid on the degradation were also tested. The results were compared with Degussa P-25 TiO2 at the same degradation conditions. Degradation products were detected using LC-MS technique. The probable pathways for the formation of degradation products were proposed. International Bureau of Federal Ministry for Education and Research (JULICH 42.6) Firat University Scientific Research Projects Management Unit (AFP 2002/53)

In Germany about 11 million t/a of municipal solid waste is incinerated giving 3 million t/a of ashes (slags). The assessment of the ashes and their possible usage get increasing attention worldwide. Several leaching tests have been developed. However, most of them consider the total concentrations of soluble species only.

Colloids are known to be the often neglected phase for the transport of pollutants in aquatic ecosystems. This book covers the basics of abiotic colloid characterization, of biocolloids and biofilms, the resulting transport phenomena and their engineering aspects. The contributors are leading specialists devoted to colloidal sciences. The discussion reflects their broad scope of viewpoint and depth of expertise. Coverage includes theoretical considerations, results from model experiments, and field studies.

High performance anion exchange chromatography with pulsed amperometric detection (HPAE-PAD) was used for the determination of eleven monosaccharides. Three analytical columns with different selectivities were tested, and the resulting separations were compared calculating precision and detection limits. The monosaccharides could be separated on CarboPAC PA10 in one analysis run with the lowest detection limits and a high precision. For the determination of polysaccharides and humic bound carbohydrates in natural organic matter, an hydrolysis step had to be carried out. With the exception of fructose, the recoveries varied between 56% and 83%. The described methods were applied for the determination of bound carbohydrates in a bog lake water and a soil extract without preconcentrating the samples.

The photodegradation of bisphenol A (BPA) in pure water, surface water and wastewater effluents was studied. The effect of different hydrogen peroxide concentrations on degradation was investigated. The rate of BPA photolysis in the presence of hydrogen peroxide was lower in wastewater effluent than in purified water. Phenol, 1,4-dihydroxylbenzene and 1,4-benzoquinone were identified by means of HPLC as intermediate products of the photodegradation of bisphenol A. In addition, the disappearance of the estrogenic activity of bisphenol A during irradiation was shown by the YES test. Based upon the YES test results, there was a strong decrease of estrogenic activity of parent compound after 120 min irradiation in the presence of hydrogen peroxide.

The photolysis of nonylphenol (NP) was investigated using a solar simulator in the absence/presence of dissolved organic matter (DOM), HCO 3 −, NO 3 − and Fe(III) ions. The effects of different parameters such as initial pH, initial concentration of substrate, temperature, and the effect of hydrogen peroxide concentration on photodegradation of nonylphenol in aqueous solution have been assessed. The results indicate that the oxidation rate increases in the presence of H 2 O 2 , Fe(III) and DOM with dissolved organic carbon concentrations not higher than 3 mg L − 1 . Phenol, 1,4-dihydroxylbenzene and 1,4-benzoquinone were identified as intermediate products of photodegradation of nonylphenol, through an HPLC method. In addition, the disappearance of the estrogenic activity of nonylphenol during irradiation using YES test was investigated. Based upon the YES test results, there was a strong decrease of estrogenic activity of nonylphenol after 80 h irradiation in the presence of hydrogen peroxide.

The biofilm-forming fungus, Aureobasidium pullulans DSM 2404, was grown in a bead-packed reactor. Alterations within the reactor were analysed in several cross-sectional slices by magnetic resonance imaging (MRI) with flow contrast. For the first time, biofilm accumulation could be continuously elucidated without using any contrast agents, and the non-stationary flow through the fixed-bed reactor could be visualized. The results indicate that the non-stationary flow through the biofilm reactor changes significantly due to the changing reactor morphology. Preferential flow lines arise during biofilm formation. The accumulation of the biomass was determined and compared to gravimetrical biomass data. The described technique can be used to monitor hydrodynamic transport, and to combine flow-field characteristics with morphological data for the prediction of undesirable reactor processes, e.g. clogging.

Fulvic acids isolated by the XAD-method from anaerobic and aerobic landfill leachates are compared with samples isolated from a soil extract and from bog lakes. Elemental composition, functional groups, and spectroscopic and chromatographic data suggest that there is an "agein" effect from the leachate samples to the soil and brown-water samples.

The interaction of metals and natural organic matter (NOM) is of influence on the metal transport in aquatic systems and soil. In the presented study, NOM of a brown water lake was oxidized with UV irradiation to elucidate the influence of oxidative degradation on the metal complexing properties of NOM. UV/Vis and fluorescence spectroscopy, as well as size-exclusion chromatography (SEC) with online detection of UV absorption, fluorescence and metal concentration were used to investigate the property changes of NOM caused by oxidation. After oxidation, the fluorescence intensity of NOM increased considerably despite a decrease in the UV absorption. The SEC experiments showed a shift towards smaller molecular sizes in the oxidized NOM samples and a decrease in the stability constants of corresponding Al-NOM complexes. For Pb no such effect could be determined. The studies on the dissociation kinetics of metal-NOM complexes revealed a slower dissociation of Al and Pb complexes with original NOM compared to oxidized NOM. The determined dissociation rate constants were used to predict the migration of metal ion-NOM complexes in column experiments. The experimental data and model predictions were in good agreement for the divalent metals Pb and Zn, but differed substantially for Al.

The changes in waste management policy caused by the massive generation of waste materials (e.g. construction and demolition waste material, municipal waste incineration products) has led to an increase in the reuse and recycling of waste materials. For environmental risk assessment, test procedures are necessary to examine waste materials before they can be reused. In this article, results of column and lysimeter leaching tests having been applied to inorganic compounds in a reference demolition waste material are presented. The results show a good agreement between the leaching behaviour determined with the lysimeter unit and the column units used in the laboratory. In view of less time and system requirements compared to lysimeter systems, laboratory column units can be considered as a practicable instrument to assess the time-dependent release of inorganic compounds under conditions similar to those encountered in a natural environment. The high concentrations of elements in the seepage water at the initial stage of elution are reflected by the laboratory column leaching tests. In particular, authorities or laboratories might benefit and have an easy-to-use, but nevertheless reliable, method to serve as a basis for decision-making.

Swimming pool water treatment in general includes flocculation, sand filtration, and subsequent disinfection with chlorine. The continuous chlorination and input of organic material by bathers in combination with recirculation of the pool water leads to an accumulation of disinfection by-products (DBPs) in the water. Several DBPs have been identified as human carcinogens and are thought to cause allergic asthma. Therefore, the elimination of DBPs is one major aim of pool water treatment. Using membrane filtration as an alternative treatment technology, DBPs can be removed more efficiently than with conventional treatment. In this study membrane filtration and genotoxicity testing were applied for the characterization of pool water constituents and for the identification of the necessary molecular weight cut off of the membrane for an efficient elimination. Two-step membrane filtration revealed that most of the DBPs (as adsorbable organically bound halogen, AOX) were present in the molecular weight fraction below 1000 g/mol. The fraction below 200 g/mol contained more than 30% of the AOX. The distribution of the dissolved organic carbon (DOC) across the fractions was similar to that of the AOX. The genotoxicity was found to be strongest in the low-molecular weight fraction. Thus, considerable DBP removal by membrane treatment requires membranes with low-molecular weight cut offs down to 200 g/mol. The comprehensive elimination of the genotoxic compounds requires further treatment steps.

The yeast estrogen screen was introduced as biological detection method for high performance thin layer chromatography. Yeast cells were grown directly on HPTLC plates, where in the presence of estrogenic substances the production of the enzyme β-galactosidase was induced. For the natural ligand 17 β-estradiol, sensitivity could be improved by a factor of 20 using the fluorogenic substrate 4-methylumbelliferyl β-D-galactopyranoside instead of the chromogenic substrate chlorophenol red-β-D-galactopyranoside. The fluorescence intensity of “estrogenic” zones was measured using a commercial TLC-Scanner. A nearly full dose-response curve was obtained for 17 β-estradiol masses between 2.75 and 550 pg, or concentrations of 2.75 to 550 μg L−1.

LC-MS has become an invaluable technique for trace analysis of polar compounds in aqueous samples of the environment and in water treatment. LC-MS is of particular importance due to the impetus it has provided for research into the occurrence and fate of polar contaminants, and of their even more polar transformation products. Mass spectrometric detection and identification is most widely used in combination with sample preconcentration, chromatographic separation and atmospheric pressure ionization (API). The focus of the first part of this review is directed particularly toward instruments and method development with respect to their applications for detecting emerging contaminants, microorganisms and humic substances (HS). The current status and future perspectives of 1) mass analyzers, 2) ionization techniques to interface liquid chromatography (LC) with mass spectrometry (MS), 3) methods for preconcentration and separation with respect to their application for water analysis are discussed and examples of applications are given. Quadrupole and ion trap mass analyzers with electrospray ionization (ESI) and atmospheric pressure chemical ionization (APCI) are already applied in routine analysis. Time-of-flight (TOF) mass spectrometers are of particular interest for accurate mass measurements for identification of unknowns. For non-polar compounds, different ionization approaches have been described, such as atmospheric pressure photoionization (APPI), electrochemistry with ESI, or electron capture ionization with APCI. In sample preconcentration and separation, solid phase extraction (SPE) with different non-selective sorbent materials and HPLC on reversed-phase materials (RP-HPLC) play the dominant role. In addition, various on-line and miniaturized approaches for sample extraction and sample introduction into the MS have been used. Ion chromatography (IC), size-exclusion chromatography (SEC), and capillary electrophoresis (CE) are alternative separation techniques. Furthermore, the issues of compound identification, matrix effects on quantitation, development of mass spectral libraries and the topic of connecting analysis and toxicity bioassays are addressed.

Environmental contaminants of recent concern are pharmaceuticals, estrogens and other endocrine disrupting chemicals (EDC) such as degradation products of surfactants, algal and cyanobacterial toxins, disinfection by-products (DBPs) and metalloids. In addition, pesticides (especially their transformation products), microorganisms, and humic substances (HS), in their function as vehicles for contaminants and as precursors for by-products in water treatment, traditionally play an important role. The present status of the application of LC-MS techniques for these water constituents are discussed and examples of application are given. Solid-phase extraction with various non-selective materials in combination with liquid chromatography (LC) on reversed-phase columns have been the most widely used methods for sample preconcentration and separation for different compound classes like pesticides, pharmaceuticals or estrogens. Electrospray ionization (ESI) and atmospheric pressure ionization (APCI) are the most frequently used ionization techniques for polar and ionic compounds, as well as for less polar non-ionic ones. The facilities of LC-MS have been successfully demonstrated for different compound classes. Polar compounds from pharmaceuticals used as betablockers, iodinated X-ray contrast media, or estrogens have been determined without derivatization down to ultratrace concentrations. LC-MS can be viewed as a prerequisite for the determination of algal and cyanobacterial toxins and the homologues and oligomers of alkylphenol ethoxylates and their metabolites. Tandem mass spectrometric techniques and the use of diagnostic ions reveal their usefulness for compound-class specific screening and unknown identification, and are also valid for the analysis of pesticides and especially for their transformation products. Structural information has been gained by the application of LC-MS methods to organometallic species. New insights into the structural variety of humic substances have been made possible by FT-ICR-MS due to its ultrahigh mass resolution. Finally, exciting possibilities for rapid detection and identification of microorganisms have been made possible by MALDI and LC-MS methods.

The transport of metal ions (Al, Fe, Zn, Pb) complexed by natural organic matter (NOM) was investigated by column experiments. Direct breakthrough of metal-NOM complexes was observed after elution of one bed volume for Al, Fe, and Pb, but not for Zn. This observation cannot be understood assuming local thermodynamic equilibrium in the columns. Hence, a model was developed, taking into account the kinetics of the interactions of metal ions with NOM and the solid phase. Of all possible reactions during passage through the column, the dissociation of the metal-NOM complexes was assumed to be the rate-determining step. Dissociation-rate constants were determined by cation-exchange experiments with a non-NOM-adsorbing cation-exchange resin (Chelex-100). These rate constants were used to predict the migration of metal-NOM complexes in the column experiments. Experimental and modeling results were in good agreement for the bivalent metal ions. Also, the model well predicted the pH dependence of breakthrough of trivalent metal ions and the differences between Al and Fe breakthrough on a qualitative basis. This leads to the conclusion that the dissociation kinetics of metal-NOM complexes is an essential parameter for the estimation of NOM-facilitated metal transport. However, for the trivalent metals, Al and Fe, the model overestimated the direct breakthrough, thus giving a worst case prediction of metal transport. With the help of coupling size-exclusion chromatography to inductively coupled plasma-mass spectrometry, the formation of Al-hydroxide and Fe-hydroxide colloids in addition to NOM complexes was detected. These colloids, which were not considered in the model, were partially filtered off in the column, thus leading to overestimation of metal breakthrough.

Recorded molecular weights (MWs) for humic substances (HS) range from a few hundred to millions of daltons. For purposes of defining HS as a specific class of chemical compounds, it is of particular importance to ascertain if this broad range of MWs can be attributed to actual variability in molecular properties or is simply an artifact of the analytical techniques used to characterize HS. The main objectives of this study were (1)to establish if a preferential range of MWs exists for HS and (2) to determine any consistent MW properties of HS. To reach the goal, we have undertaken an approach to measure under standardized conditions the MW characteristics of a large set of HS from different natural environments. Seventy-seven humic materials were isolated from freshwater, soil, peat, and coal, such that each possessed a different fractional composition: humic acid (HA), fulvic acid (FA), and a nonfractionated mixture of HA and FA (HF). Size exclusion chromatography (SEC) was used as the analytical technique to determine molecular weight characteristics. The MW distributions were characterized by number (Mn) and weight (Mw) average MW, and by polydispersity. The complete range of Mw values varied within 4.7-30.4 kDa. The maximum Mw values were observed for peat HF and soil HA, whereas the smallest weights were measured for river water HF. Maximum values of polydispersity (3.5-4.4) were seen for peat HF and soil HA, while much lower values (1.6-3.1) were found for all preparations isolated with XAD-resins. Statistical evaluation showed consistent Mw and Mn variations with the HS source, while polydispersity was mostly a function of the isolation procedure used. A conclusion was made that HS have a preferential range of MW values that could characterize them as a specific class of chemical compounds.

Three different industrial wastewaters from the production of stilbene-based fluorescent whitening agents were investigated with regard to the applicability of advanced oxidation processes combined with biodegradation. Oxidation processes included the application of ozone, hydrogen peroxide, UV-radiation and Fenton's reagent (Fe2+/H2O2). Characterization of the combined chemical–biological treatment was done by sum parameters and HPLC analysis. In addition, toxicity was determined using the luminescence inhibition test. Results showed that processes producing OH-radicals without the need of UV-irradiation proved to be suited for the oxidation of all three wastewaters. H2O2/UV processes were ineffective due to the high inner filter effect of the effluents. Comparing the combined oxidative-biological process with biological treatment, the applied pre-oxidation steps did not always lead to a significant improvement of the biological degradation. In one case, an inverted treatment starting with biodegradation followed by oxidation turned out to be the preferable procedure. After oxidation with ozone or ozone combined with UV-irradiation, an increase in toxicity was partly observed indicating the formation of toxic intermediate products. In some cases samples had to be diluted before the biodegradation step to achieve a better biodegradability.

Natural organic matter (NOM), derived from degradation of living organism matter, can significantly control the fate and transport of chemical components, particularly metal ions, by forming organometallic complexes in aquatic systems. Column experiments were performed to study the mobility of humic acids (HA) and Hg. Single component (HA or Hg) and multicomponent (Hg and HA) experiments were conducted to assess transport behaviour of Hg in the presence of HA. A natural quartz sand was used as porous sorbing medium. HA breakthrough curves (BTCs) showed a first step with a sharp front followed by an important tailing over a long period of time. The tailing of HA BTCs is assumed to be due to slow sorption kinetics of HA onto the quartz sand and the non linear nature of the sorption isotherms. The time required to get steady-state concentration for organic C depended on the inlet HA concentration. HA sorption depends also on pH, the highest HA sorption being observed at pH

Gel permeation chromatography (GPC) in combination with ultraviolet (UV) and sensitive dissolved organic carbon (DOC) detection was used to investigate the structural changes caused by ozonation and chlorination. Oxidation processes were applied to a fulvic acid (HO10FA) sample which was extracted from Hohloh Lake, Germany. Biological degradation by means of assimilable organic carbon (AOC) of the FA sample was monitored by GPC elution diagrams. It is shown that ozonation and subsequent chlorination result in partial decomposition of the high-molecular-mass components of FA to low-molecular-mass hydrophilic compounds which are more biodegradable by microorganisms.

The drinking water industry is required to ensure effective disinfection while minimizing the formation of disinfection by-products (DBPs). A multitude of data exists for the occurrence and the health effects of DBPs, primarily for trihalomethanes (THMs) and other chlorination by-products. The consumption of chlorinated drinking water has been linked to cancer and to a variety of adverse reproductive outcomes. Chloroform, the main THM identified in chlorinated water, is a probable human carcinogen. A significant proportion of the mutagenicity in chlorinated drinking water is attributed to the hydroxyfuranone MX. Different approaches have been applied to investigate the reactions of chlorine and other oxidants like ozone, chloramine and chlorine dioxide during the water treatment process. Especially the influence of precursors like natural organic matter (NOM) is an important subject of current research. Nevertheless, the reactions and products have not yet been clearly identified even with the aid of newly developed analytical tools. In the water treatment practice the three general approaches for the reduction of DBPs are to control their formation by using alternative disinfectants, to remove them after formation, or to remove their precursors. For this purpose the characterization of NOM is important to optimize the removal process, including coagulation, adsorption and membrane technologies.

A method for enumerating micro-organisms degrading polycyclic aromatic hydrocarbons (PAHs) was developed. The micro-organisms present in water samples are incubated in 96-well microplates, in which the desired PAHs are available as sole carbon source in a liquid mineral-salts medium (MSM). Walls and bottoms of the wells in the microplates are covered with PAHs by dissolving them in a non-polar solvent and pipetting this solution into the wells. After solvent elimination under vacuum, the PAHs remain on the surface of the wells. The formation of coloured products during microbial degradation of PAHs causes colouring of the MSM, thus allowing evaluation of the cell titre by determining the most probable number. Usage of an electronic multichannel pipette makes the work faster and more effective. This allows the inoculation of several microplates pre-treated with different PAHs out of one serial dilution. On the one hand, this method is very effective in screening the usability spectrum of different PAHs microorganisms; on the other hand it allows the additional employment of other sources of hydrocarbons.

Natural organic matter from drinking water sources was fractionated, and the fractions were characterized by NMR and SEC with the aim of relating NOM structure to treatability. Organic matter was isolated from two Australian surface waters (Horsham, Moorabool) by reverse osmosis and from a groundwater (Wanneroo) by anion exchange. The isolates were fractionated according to polarity and charge by resin adsorption. 13C NMR spectra of the freeze-dried fractions showed the most hydrophobic fraction to be high in aliphatic and aromatic carbon while slightly hydrophobic organics have more carbonyl and alkoxyl carbon. The Horsham and Wanneroo hydrophilic fractions show strong alkoxyl signals attributed to carbohydrate. Moorabool hydrophilics contain aromatic (phenolic) carbon; the apparent absence of carbohydrate appears to be an artifact. Size-exclusion chromatograms were recorded on the original and fractionated organics with both UV and dissolved organic carbon detection. The Horsham and Moorabool organics have similar molecular size distributions while Wanneroo is dominated by strongly absorbing species having large hydrodynamic radii. The hydrophobic and charged hydrophilic fractions also have high apparent MW, while the neutral fraction is higher in low-MW compounds of relatively low specific absorbance, suggestive of carbohydrates.

The influence of natural organic matter (NOM) on the adsorption of Al, Fe, Zn, and Pb onto clay minerals was investigated. Adsorption experiments were carried out at pH = 5 and pH = 7 in the presence and absence of NOM. In general, the presence of NOM decreased the adsorption of metal ions onto the clay particles. Al and Fe were strongly influenced by NOM, whereas Zn and Pb adsorption was only slightly altered. The interaction of the metal ions with the minerals and the influence of NOM on this interaction was investigated by coupling SdFFF with an inductively coupled plasma mass spectrometer (ICPMS) or an inductively coupled plasma atomic emission spectrometer (ICPAES). Quantitative atomization of the clay particles in the ICP was confirmed by comparing elemental content determined by direct injection of the clay into the ICPMS with values from acid digestion. Particle sizes of the clays were found to be between 0.1 and 1 microm by sedimentation field-flow fractionation (SdFFF) with UV detection. Aggregation of particles due to metal adsorption was observed using SdFFF-ICPMS measurements. This aggregation was dependent on the specific metal ion and decreased in the presence of NOM and at higher pH value.

The linearity of calibration curves in ion chromatography with suppressed conductivity detection using hydroxide eluents was investigated. Theoretical calibration curves were derived for strong electrolytes and weak monobasic acids and the results compared with experimental data. At low concentrations up to 1 micromol l(-1) the autoprotolysis of water induces left-curved calibration functions even for strong electrolytes like nitrate. The experimental data are best described by a quadratic function, the differences between linear and quadratic regression being up to 10%. At higher concentrations the calibration curves for strong electrolytes are linear. Due to incomplete dissociation, the calibration curves for weak mono- and dibasic acids show a right curvature. Thus, depending on the analyte and the concentration range of interest, analysts should carefully choose between a linear and a quadratic regression function.

Preface. List of Authors. List of Abbreviations. Setting the Scene. The Relevance of Reference Materials Isolation and General Characterization. Element Determination and its Quality Control in Fractions of Refractory Organic Substances and the Corresponding Original Water Samples. Structural Investigations. Heavy Metal and Halogen Interactions with Fractions of Refractory Organic Substances Separated by Size exclusion Chromatography. Characterization of Refractory Organic Substances and Their Metal Species by Combined Analytical Procedures. Application of Nuclear Magnetic Resonance Spectroscopy to Structural Investigations of Refractory Organic Substances Principles and Definitions. Structural Characterization of Refractory Organic Substances by Solid state High resolution 13C and 15N Nuclear Magnetic Resonance. Quantification of Substructures of Refractory Organic Substances by Means of Nuclear Magnetic Resonance. Nuclear Magnetic Resonance Spectroscopy Investigations of Silylated Refractory Organic Substances. Isotopic Evidence for the Origin and Formation of Refractory Organic Substances. Analytical Pyrolysis of Humic Substances and Dissolved Organic Matter in Water. Charaacterization of Refractory Organic Substances by HPLC/MS. UV Visible Spectroscopy and the Potential of Fluroscent Probes. Stationary and Time resolved Fluorescence for Refractory Organic Substances Characterization. Structural Characterization of Refractory Organic Substances by Pyrolysis GC/FTIR. X ray Microscopy Studies of Refractory Organic Substances. Fractionation of Refractory Organic Substances by Electrophoresis. Occurence of Amino Acids, Carbohydrates, and Low molecular weight Organic Acids in Refractory Organic Substances. Serological Characteization of Refractory Organic Substances. Biochemical and Biological Characterization. Formation, Utilization and Transformation of Some Refractory Organic Substances by Aquatic Microorganisms. Effect of Microorganisms on the Formation and Transformation of Iodine Species of Refractory Organic Substances. The Influence of Refractory Organic Substances on Bacterial Colonization and Diversity Patterns. Influence of Refractory Organic Substances on Enzyme Activity in vivo and DNA Damage of Aquatic Microorganisms. Effects of Dissolved Organic Matter on the Bioconcentration of Organic Contaminants and on Reproduction in Aquatic Invertebrates. Molecular Interactions. Sorption of Dissolved Organic Matter on Soil Particles and its Dependence on their Surface charge Properties. Dissolved Organic Carbon in Seepage Water Production and Transformation During Soil Passage. Refractory Organic Substances in Aggregated Forest Soils Retention versus Translocation. Refractory Organic Substances Derived from Organic Amendments in Soil Formation, Translocation, and Interaction with Xenobiotics. Analysis of the Binding Amitrole and Anilazine to Aquatic and Terrestrial Refractory Organic Substances. Sorption and Chemical Reactions of Polycyclic Aromatic Hydrocarbons with Dissolved Refractory Organic Substances and Related Model Polymers. Investigation of the Interactions between Polycyclic Aromatic Compounds and Refractory Organic Substances with Stationary and Time resolved Fluorescence and Absorption Spectroscopy. Index. Author Index.

A liquid chromatography (LC) method followed by electrospray ionization (ESI) and tandem mass spectrometry (MS–MS) was developed for the quantification of acidic naphthalene derivatives in the concentration range 0.1 to 100 μg/l without excessive sample preparation. For optimal sensitivity the LC–MS–MS measurements were performed recording mass fragmentation by collision induced dissociation in the multiple reaction mode. The collision energy was optimized for every analyte. The matrix effects of the sample were investigated by spiking standards of 1-naphthoic acid with humic acid (HA) and with calcium chloride. While HA decreased the signal intensity an increase was observed in the presence of calcium chloride. For the investigated groundwater samples of a tar oil contaminated site a complete separation of the analytes from the sample matrix by reversed-phase separation could be obtained. The absence of matrix effects on quantification results was confirmed by comparison of results based on external calibration with those based on standard addition of the analytes to a groundwater sample. In four groundwater samples of the contaminated site naphthalene derivatives like 1-naphthoic acid, 2-naphthoic acid, 1-naphthylacetic acid, 2-naphthylacetic acid, 1-hydroxy-2-naphthoic acid, 2-hydroxy-3-naphthoic acid, and naphthyl-2-methylenesuccinic acid have been detected.

Results of a systematic study on the water quality in the Moskva River and Oka River in western Russia are presented. The goal of the study was (1) to implement a water-quality survey concept, (2) to identify major pollutants and pollution sources, and (3) to study the influence of the Moskva River on the water quality in the Oka River. The results show that ammonium, phosphate, nitrate, AOX, and polycyclic aromatic hydrocarbons (PAH) are the major pollutants in both rivers. The Moskva River is significantly polluted. Concentrations of the pollutants exceed the corresponding water-quality targets by factors up to 14. The Oka River before the inflow of the Moskva River is fairly polluted. The water quality of the Oka River is strongly influenced by inputs of pollutants from the Moskva River. Longitudinal concentration profiles and multivariate data evaluation indicate insufficiently treated municipal wastewater from the Moscow area as the major pollution source in the studied river systems. With the results of the study, a basis for the effective implementation of measures for the improvement and protection of the water quality in the Moskva River and Oka River has been established.

The sorption of various phenols to Aldrich-HA and BSA was investigated by solid phase microextraction (SPME). The Aldrich-HA sorption with log K(DOC)-values between 2 and 3 was determined, whereas the sorption to BSA with log K(DOC)-values between 2 and 6 was much stronger. To enable an estimation of sorption constants a QSAR model was investigated. The linear free energy relationship (LFER) model showed a good correlation between the sorption constants and the log K(OW)-values with correlation coefficients of R = 0.910 and R = 0.878 for Aldrich-HA and BSA, respectively.

The TiO2-catalyzed photooxidation of arsenite (As(III)) to arsenate (As(V)) was studied in aqueous TiO2 suspensions using a solar simulator which emitted ultraviolet and visible radiations. The concentration of As(III) was varied between 50 microg l(-1) and 10 mg l(-1), and the concentration of TiO2 between 1 mg l(-1) and 50 mg l(-1). Total oxidation of As(III) to As(V) occurred within minutes. The concentration of As(III) declined exponentially which indicates first-order kinetics. In the pH range between 5 and 9 there was no significant influence of the pH of the suspension on the reaction rate. Batch experiments without irradiation showed that part of the arsenic was adsorbed on the TiO2 surface. When using 100 microg l(-1) As and between 1 mg l(-1) and 50 mg l(-1) TiO2, 8-39% of As(III) and up to 73% of As(V) were adsorbed by TiO2. As(III) was also oxidized by UV radiation in the absence of TiO2, but the reaction was slower than in the presence of TiO2 resulting in an irradiation time too long for practical use. In addition, oxidation of As(III) in the presence of TiO2 was also observed under solar irradiation within a few minutes.

Introduction and Historical Outline Occurrence Hydrophobic and Hydrophilic Fractions Chemical Structure Elemental Composition Molecular Size Distribution and Charge Spectral Absorbance and Fluorescence Infrared Spectra Mass Spectrometry NMR Spectroscopy Soft Hydrolysis Interaction of Humic Matter with Other Water Constituents Fate of Humics in Technical Application of Water Viewing the Function in Aquatic Ecosystems Keywords: aquatic humic substances; hydrophobic and hydrophilic fractions; chemical structure; elemental composition; molecular size distribution and charge; spectral absorbance and fluorescence; infrared spectra; mass spectrometry; NMR-spectroscopy; soft hydrolysis; interaction; function in aquatic ecosystems

In the present work the adsorption kinetics of the six metal ions aluminum, zinc, mercury, lead, copper, and cadmium onto living microalgae were measured. The freshwater green microalga Scenedesmus subspicatus, the brackish water diatom Cyclotella cryptica, the seawater diatom Phaeodactylum tricornutum, and the seawater red alga Porphyridium purpureum were the subject of investigation. In most cases the adsorption rate of the metals could be well described by using the equation of the Langmuir adsorption rate expression. Inverse parameter estimation allowed the determination of the rate constants of the adsorption process and the maximum metal content of the algae. The highest values for the rate constant were obtained for Porphyridium purpureum followed by Phaeodactylum tricornutum. High values for the maximum content were obtained for Cyclotella cryptica and Scenedesmus subspicatus. The maximum rate constant was 24.2 l h−1 for the adsorption of Hg to Porphyridium purpureum whereas the maximum metal content (0.243 g g−1) was obtained for Zn on Cyclotella cryptica. A comparison of these values with those obtained for the mineral siliceous earth exhibiting low maximum content and high adsorption rates reveals that the mechanism of adsorption onto the algae is a mixture of adsorption and accumulation.

Pharmaceuticals belong to the environmentally relevant compounds. They are produced and administered for human and animal medical care. Due to the amount and types of applications pharmaceuticals can reach the environment, in particular the aquatic systems. Being produced and applied with the aim of causing a biological effect, their occurrence in the environment is of ecotoxicological interest. In particular this is of importance for antibiotics, but also for antineoplastics, hormones (compounds with endocrinic effects) and various compounds and metabolites that have already been detected in sewage plant effluents and surface waters in considerable concentrations (e.g. bezafibrate, clofibric acid, ibuprofen) (Stumpf et al. 1999; Hirsch et al. 1999). In particular, clofibric acid — a therapeutically active metabolite of clofibrate ethyl, etofibrate and ethofyllinclofibrate — shows a highly persistent behaviour in the aquatic environment and was already found in ground and drinking water in the city of Berlin (Heberer et al. 1998; Heberer and Stan 1996) as well as in the North Sea (Buser et al. 1998).

The sorption of phenol and different halogenated phenols to natural organic matter of a brown water lake (HO14), of a compost extract, of Aldrich humic acid (Aldrich-HA), and to the protein bovine serum albumin (BSA) was investigated using solid phase microextraction (SPME). The limit of determination for the SPME analysis was < 15 microg/l for all phenols investigated. The extraction coefficients K(F) were calculated according to a first-order extraction kinetics. In general, the extraction equilibrium was established faster due to the presence of dissolved organic matter (DOM). The highest sorption capacity of phenols was observed for BSA with log K(OC) values in the range between 2 and 6. For the compost extract and HO14 only a small sorption of the investigated phenols was determined. On the other hand, Aldrich humic acid showed a reasonable sorption of phenols with log K(OC) values between 2 and 3. The sorption to DOM decreased when the pH of the solution was increased.

Aus Anfangen in der Form von fachspezifischen Untersuchungen in Teilgebieten des Bauingenieurwesens, der Chemie, der Biologie zu Einzelfragen der Verbesserung des menschlichen Lebensraumes entstanden, ist die Umweltforschung heute das Ergebnis einer gesellschaftlichen Entwicklung, die ihren Ursprung in den 6oer Jahren hatte. Insbesondere seit der Stockholmer Umweltkonferenz im Jahre 1972, als UNEP, die Umweltagentur der Vereinten Nationen, gegrundet wurde, ist allmahlich die Einsicht von der Endlichkeit der naturlichen Ressourcen einerseits und anderseits von der zunehmenden Zerstorung des naturlichen Lebensraumes durch menschliche Handlungen in das Bewusstsein der Menschen und der Politik gedrungen.

By means of simulated sunlight, the influence of natural organic matter (NOM) on the photochemical degradation of halogenated pesticides in the absence and presence of nitrate as a precursor of the highly reactive OH radicals in aqueous solutions and freshwater was investigated. Solutions of dichlorprop or terbutylazine (a) in phosphate-buffered demineralized water containing nitrate and/or NOM and (b) in natural freshwaters were irradiated by a 1000-W Xe short-arc lamp. The collimated beam was filtered using a combination of optical filters (WG 320 and WG 295) to simulate the solar spectrum under summer midday conditions. In the absence of nitrate and NOM, the pesticides were degraded photolytically by simulated sunlight. The degradation rates depended on the absorption spectrum in the UVB range and the quantum yield of the degradation. The photochemical degradation of the pesticides was faster in the presence of nitrate due to the sunlight-induced formation of OH radicals. In the absence of nitrate, low concentrations of NOM of a brownwater lake accelerated the degradation due to the formation of reactive species by NOM. At higher concentrations of NOM, the inner filter effect of NOM lowered the degradation rates. In the presence of 50 mg l−1 nitrate, NOM decreased the degradation rate significantly. In case the natural water samples were used as a matrix for the experiments (nitrate concentrations between 2 mg l−1 and 15 mg l−1, DOC concentrations below 2.3 mg l−1), NOM acted mainly as a radiation filter and as a scavenger of OH radicals. As a consequence, in most freshwater systems, the accelerating effect of NOM by the formation of reactive species is of minor importance compared to the inner filter effect and to radical scavenging.

A method for the analysis of the polar aromatic compounds 1H-quinolin-4-one (Q), 10H-acridin-9-one (A), 5H-phenanthridin-6-one (P) and 9H-fluoren-9-one (F) in aqueous solutions has been developed. The method comprises steps for sample preparation (solid-phase extraction, cleanup) and analytical determination by means of reversed-phase high-performance liquid chromatography (RP-HPLC). For the cleanup step the suitability of two different sorbents (alternative A: silica gel, alternative B: LiChrolut EN) was investigated. Alternative B depicted several advantages, in particular higher sorbent capacity, faster and less complicated handling, higher recovery and better reproducibility. For Q, A and P, reproducibility of all method steps is better than 13%, with recovery rates ranging from 76% to 105% (n=3). Alternative B was applied to groundwater samples from a former gas plant. The analytes A and P could be detected at concentrations in the micro/l range.

The effectiveness of water treatment processes in removing natural organic matter varies with the nature of the natural organic matter (NOM), its molecular size, polarity and charge density, and with properties of the raw water such as turbidity and hardness. In some cases conventional alum treatment is inefficient. We have compared NOM removals achieved by conventional and polymer-based processes in bench-scale treatment of reconstituted ground and surface waters of varying colour, made from NOM isolated from the same waters. NOM isolates were fractionated by adsorption on non-functionalised resins and an anion exchanger, and characterised by size exclusion chromatography. Jar tests with the isolated NOM compared coagulation with polyelectrolytes, alum, clays and metal oxides, with each of the inorganics being in conjunction with a polyelectrolyte. Jar tests on reconstituted waters with alum and/or cationic polyelectrolyte show synergistic benefits from combinations of the two. The more hydrophobic NOM fractions were the most easily removed by polymer. The performance of cationic polymers improved significantly with increasing charge density and molecular weight. An alum/polymer combination is the most attractive treatment option.

Biogenic organic matter (BOM) is of ubiquitous relevance in all aquatic systems. This is due to the fundamental function of the natural organic matter in combination with the microbial activity which guarantees the degradation in and the self purification of water in the hydrological cycle. In addition, the refractory part of the widely distributed BOM acts as effective adsorbent for most water constituents, and in case of mobile fractions as active vehicle for pollutants. In contrast to the broad importance of the occurrence and role of BOM, there is a fairly small variety for its analytical characterization. Especially in the field of in-situ measurements and of the determination in the original concentration range of aqueous samples, relatively little data have been collected. This is partly due to the complex structure of BOM, partly to the limited availability of analytical methods suited for that type of investigations. The aim of the paper is to give typical examples for the a) physical/chemical, b) microbiological and c) technologically orientated methods of the analytical characterization of BOM in aqueous solution and to draw conclusions on the function of BOM in aquatic systems and their use for man.

Leaching test procedures allow an assessment of the hazardous potential of a contaminated soil or waste sample with regard to leaching behaviour in the subsurface or on a landfill. The CEN technical committee TC292 “Waste Characterization” has proposed three levels of testing: 1.) Basic characterization 2.) Compliance tests 3.) On-site verification testing