Organic contaminants in Croatian municipal wastewaters.

Municipal wastewaters are among the most important sources of waste materials released into the environment. In Croatia, this problem is especially pronounced since only 4.4% of the total wastewaters are subject to complete mechanical and biological treatment.

Effects of zeolites on cultures of marine micro-algae: A brief review.

Goal, Scope And Background: The cation-exchange capacity of zeolites is well known and has been increasingly explored in different fields with both economic and environmental successes. In aquatic medium with low salinity, zeolites have found multiple applications. However, a review of the literature on the applications of zeolites in salt waters found relatively few articles, including some recently published papers.

Ultrastructural aspects of hepatic coccidiosis caused by Goussia lusca n. sp. (Apicomplexa: Coccidia) infecting Trisopterus luscus (Gadidae) from the NE Atlantic Ocean.

Goussia lusca n. sp. is described from the liver of pouting Trisopterus luscus from the NE Atlantic Ocean in Ibero-Atlantic Portuguese and Spanish waters.

Enhancing diatom growth by using zeolites to change seawater composition.

Aims And Scope: The purpose of this study was to test whether two zeolites produced synthetically (products of zeolitic nature, PZN) could influence either the yield of a diatom culture or the chemical changes in the cultures. For this purpose, Phaeodactylum tricornutum was used as test organism in a culture medium of natural seawater enriched with N and P having negligible amounts of ammonia.

Methods: The PZN ZEBEN-06 and ZESTEC-56 were used in parallel experiments.

The influence of the biometric parameters on metallothionein and metal level in the heat-treated cytosol of the whole soft tissue of transplanted mussels.

The influence of the biometric parameters (shell mass, whole soft tissue mass, condition index) on MT and metal levels in the heat-treated cytosol of the whole soft tissue of transplanted mussels was studied over the period of one year. The positive correlation of three metals (Cd, Fe, Zn) with the shell mass indicated to time-dependent increase of their contents. Strong correlation of Mn content with the whole soft tissue mass (r = 0.

Redox kinetics of adriamycin adsorbed on the surface of graphite and mercury electrodes.

Kinetics of the surface redox reactions of adriamycin (doxorubicin hydrochloride) adsorbed on paraffin-impregnated graphite electrode (PIGE) and on mercury electrode is measured by square-wave voltammetry. In 0.9 mol/L KNO3 buffered to pH 4.

Remobilization of metals from slag and polluted sediments (case study: the canal of the Deûle River, northern France).

The anthropogenic impact on the environment in the last century has proven to be very negative due to the fast development of industry. A typical example is the Deûle River in northern France, one of the most polluted sites in this region. The concentrations of Pb, Cd, Zn and Cu in river sediments are 300, 800, 50 and 15 times higher, respectively, than the background values.

Voltammetry of copper sulfide particles and nanoparticles: investigation of the cluster hypothesis.

An association of Cu with sulfide in aerobic natural waters has been attributed to these components' coexistence in clusters of sizes intermediate between mononuclear complexes and colloidal particles. This hypothesis is investigated here. Copper sulfide solid phases display size-related voltammetric behavior at Hg electrodes.

Spatial and temporal variability of carbohydrates in the northern Adriatic--a possible link to mucilage events.

Large-scale mucilage events in the northern Adriatic have become more frequent during the last few decades. Since carbohydrates (CHO) comprise one of the major constituents of the Adriatic mucilage, studying their seasonal and spatial patterns is one of the key prerequisites for the understanding of this phenomenon. This paper reports on the distribution of particulate (PTCHO) and dissolved carbohydrates (DTCHO) in the period from June 1999 to July 2002, with a special emphasis on the summer mucilage events.

Biophysical scenario of giant gel formation in the northern Adriatic sea.

The macroscopic gel phase (mucilage) appears episodically in the northern Adriatic Sea covering tens of square kilometers of sea surface. Current views leave no doubt on phytoplankton production as a proximal source of polymers constituting the gel network, but the mechanism leading to its rapid production remains unknown. We introduced electrochemical sensing of marine microparticles and atomic force microscopy to image supramolecular organization of marine gel network.

Influence of the primary structure of enzymes on the formation of CaCO2 polymorphs: a comparison of plant (Canavalia ensiformis) and bacterial (Bacillus pasteurii) ureases.

The influence of the primary structures of plant (Canavalia ensiformis) and bacterial (Bacillus pasteurii) ureases on the precipitation of calcium carbonate polymorphs in solutions of calcium salts and urea at room temperature was investigated. Despite a similar catalytic function in the decomposition of urea, these ureases exerted different influences on the crystal phase formation and on the development of unusual morphologies of calcium carbonate polymorphs. Spherical and uniform vaterite particles were precipitated rather than calcite in the presence of Bacillus urease, while the presence of Canavalia urease resulted in the precipitation of calcite only.

Copper complexing properties of melanoidins and marine humic material.

Melanoidins, condensation products of sugars and amino acids, represent a key link in the transformation of polysaccharides to humic material in the marine environment. We investigated the complexing capacity of melanoidins that were prepared in deionized water and seawater and separated into different molecular mass fractions. The copper complexing properties of humic material isolated from marine lagoon sediments were determined for comparison.

Uranium in sediments, mussels (Mytilus sp.) and seawater of the Krka river estuary.

The response of an aquatic environment to the decrease of phosphate discharges from a technologically improved transhipment terminal, situated at the Croatian Adriatic coast in the port of Sibenik, has been assessed based on uranium activity and concentration in sediment, seawater and mussels Mytilus sp. The highest 238U activities (485+/-16Bqkg(-1) dry weight) were found in the sediment sample collected from the sampling site closest to the terminal. The maximum concentrations in the sediment samples are above the natural ranges and clearly indicate the harbour activities' influence.

Elimination of aromatic surfactants from municipal wastewaters: comparison of conventional activated sludge treatment and membrane biological reactor.

Behaviour of anionic surfactants of linear alkylbenzene sulphonates (LAS) type and non-ionic surfactants of nonylphenol polyethoxylate (NPnEO) type was studied in the conventional mechanical/biological sewage treatment plant (STP) as well as using a membrane biological reactor (MBR). LAS and NPnEO were determined using high performance liquid chromatography (HPLC) equipped with spectrofluorimetric detection. Liquid chromatography/tandem mass spectrometry (LC/MS/MS) was used for identification and quantification of stable metabolites, including nonylphenol (NP), nonylphenol monoethoxylate (NP1EO), nonylphenol diethoxylate (NP2EO) and nonylphenoxy carboxylic acids (NPnEC).

Examining the suitability of mussel digestive gland to serve as a biomonitoring target organ.

In coastal marine areas, the level of metallothioneins (MTs) is monitored as the specific response to trace heavy metals and is considered as a biomarker of metal exposure. Laboratory experiments with bivalves indicate that MT synthesis is induced by Cd, Cu, Hg, Ag and Zn ions. The results of our study, conducted with the mussel Mytilus galloprovincialis, deployed 12 months in the "hot spot" area of the Kastela Bay, Dalmatia, Croatia, are evaluated considering the recommendation of MED POL Programme for estimating exposure of mussels to trace heavy metals by means of MTs.

Cadmium accumulation and Cd-binding proteins in marine invertebrates--a radiotracer study.

Tissue and subcellular accumulation of cadmium were studied in different tissues of three marine invertebrates (blue mussel Mytilus edulis, the tunicate Ciona intestinalis and the sea star Asterias rubens) using radioactive 109Cd as a tracer. The organisms were exposed to 0.05, 2 and 50 microg Cd l(-1) for 21 days.

Activity of purine catabolism enzymes during the reproductive cycle of male and female brown trout (Salmo trutta).

In order to detect predicted changes in purine catabolism during the annual reproductive cycle of brown trout, we measured the activity of xanthine dehydrogenase, urate oxidase, and allantoinase. In kidney, only xanthine dehydrogenase was detected. In female liver and kidney, the activity of these enzymes was higher in May and decreased during vitellogenesis, with urate oxidase being undetectable in this period.

Environmental contamination assessment of the surroundings of the ex-Sibenik's ferro-manganese smelter, Croatia.

The objective of this study was chemical and radiological characterization of soil samples affected by the dust emission and slag dumping from ferro-manganese smelter as well as uptake of metals by vegetation growing on that soil. Iron was the main component of metallurgical slag deposited near the smelter. Slag material was highly enriched in Zn, Cr, Cu, Co, and Pb.

Is the digestive gland of Mytilus galloprovincialis a tissue of choice for estimating cadmium exposure by means of metallothioneins?

A study performed over 12 months with caged mussels Mytilus galloprovincialis in the coastal marine zone, which is under urban pressure, reveals a temporal variation of digestive gland mass, which causes "biological dilution" of cytosolic metallothionein (MT) and trace metal (Cd, Cu, Zn, Fe, Mn) concentrations. The dilution effect was corrected by expressing the cytosolic MT and metal concentrations as the tissue content. Consequently, the changes of the average digestive gland mass coincide with the changes of MT and trace metal contents.

Identification of 5-aminosalicylic acid, ciprofloxacin and azithromycin by abrasive stripping voltammetry.

Solid microparticles of 5-aminosalicylic acid, ciprofloxacin, and azithromycin were mechanically immobilized on the surface of the paraffin impregnated graphite electrode and investigated by square-wave and cyclic voltammetry in order to develop a method for their qualitative determination. 5-Aminosalicylic acid is oxidized at 0.540 V in the quasireversible electrode reaction, which is followed by the chemical transformation of the product, while ciprofloxacin and azithromycin are oxidized at 1.

Metal and metallothionein level in the heat-treated cytosol of gills of transplanted mussels Mytilus galloprovincialis Lmk.

A stock of mussels Mytilus galloprovincialis was transplanted over 1 year to four sites in a semi-enclosed bay in Croatia which is under the influence of various sources of pollution. The positive correlation of metal (Cd, Zn, Cu, Mn, Fe) and metallothionein (MT) tissue contents based on the analysis of heat-treated cytosol of gills with shell mass, as an indicator of mussel age, indicated to accumulation of metals, as well as the increase of MTs with mussel age. The principal component analysis (PCA) revealed that 74% of total variance of obtained results could be explained through two principal components.

Silver nanoparticles as antimicrobial agent: a case study on E. coli as a model for Gram-negative bacteria.

The antimicrobial activity of silver nanoparticles against E. coli was investigated as a model for Gram-negative bacteria. Bacteriological tests were performed in Luria-Bertani (LB) medium on solid agar plates and in liquid systems supplemented with different concentrations of nanosized silver particles.

Influence of chloride and sediment matrix on the extractability of HgS (cinnabar and metacinnabar) by nitric acid.

The extractability of metacinnabar and cinnabar, alone or in the presence of some sediment components, with various concentrations of HNO3 (1, 4, 6, and 14 M) was studied. Both forms of HgS (0.2-0.

Metallothionein and metal levels in cytosol of liver, kidney and brain in relation to growth parameters of Mullus surmuletus and Liza aurata from the Eastern Adriatic Sea.

Two wild fish populations (Mullus surmuletus (striped red mullet) as a bottom, and Liza aurata (golden grey mullet) as a pelagic species, were sampled in Kastela Bay, Middle Dalmatia. Metallothionein (MT) and metal content (Cu, Zn, Cd) was determined in heat-treated supernatants (S50) of fish tissues. MT levels were statistically different in liver and kidney of sampled species, with highest value in kidney of M.

Cercaria sevillana n sp, a new cercaria (Digenea: Microphallidae) from Nassarius reticulatus (L) (Mollusca: Prosobranchia) in Portugal.

Cercaria sevillana n. sp. (Digenea: Microphallidae) was discovered infecting the gonads and digestive gland of the prosobranch Nassarius reticulatus (L.