A method for total organic chlorine determination in bleach plant recipient waters

A method, based on XAD-8 resin sorbtion and Particle Induced X-ray Emission (PIXE), was developed for Total Organic Chlorine (TOCl) determinations. The method was applied to recipient waters of a kraft bleach plant, and the determined TOCl values compared with other parameters. The detection limit was about 10 μg/l.     

PCBs,PCNs, PCDD/Fs,PAHs and Cl-PAHs in air and water particulate samples--patterns and variations

Methodology for the determination of biologically active polychlorinated biphenyls (PCBs), non-ortho PCBs, polychlorinated naphthalenes (PCNs), polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs), polycyclic aromatic hydrocarbons (PAHs) was used to investigate concentrations and patterns of certain chlorinated PAH (Cl-PAH) in source related samples using synthetic reference mixtures. Thus, in addition to the above mentioned compounds, mono-heptachlorosubstituted fluorenes, phenanthrenes/anthracenes and pyrenes/fluoranthenes (Cl-PAHs) were measured in vapour and particulate air samples from urban road tunnels, samples of settling particulate matter (SPM), and in bottom sediment samples from two point source locations (pulp and paper, and Mg-plant/Fe-Mn-smelter/chlor-alkali) and in the Baltic Sea. Concentrations in air samples followed: PAHs>PCBs>PCNs>non-ortho PCBs or Cl-PAHs>PCDD/Fs. SPM samples collected at increasing distance to the urban area of Stockholm showed: PAHs>PCBs>PCNs>PCDD/Fs>non-ortho PCBs or Cl-PAHs. For all compound groups there was a tenfold (Cl-PAHs fivefold) concentration decrease in SPM samples from highest levels in the urban water area to lowest levels at a distance of 26 km from city centre. PCB profiles of SPM showed similarities with combined profiles of Aroclor 1242 and 1254. PCN profiles of SPM showed similarities with combined profiles of Halowax 1099 and 1014. A correlation with concentration of all tested Cl-PAH and their corresponding parent PAH was found only for Cl-fluorene.     

RES3T-Rossendorf expert system for surface and sorption thermodynamics

This paper presents a digitized version of a thermodynamic sorption database, implemented as a relational database with MS Access. It is mineral-specific and can therefore be used for additive models of complex solid phases such as rocks or soils. An integrated user interface helps users to access selected mineral and sorption data, to extract internally consistent data sets for sorption modeling, and to export them in formats suitable for other modeling software. Data records comprise mineral properties, specific surface area values, surface binding sites' characteristics, sorption ligand information, and surface complexation reactions. An extensive bibliography is included, providing links not only to the above listed data, but also to background information concerning surface complexation model theories, evidence for surface species, and sorption experimental techniques.     

Compound dependence of the relationship log Kow and log BCFL

Linear relatinships between log bioconcentration factor (BCF) and log K^ow for a variety of compounds have been reported many times in the literature. Analysis of the thermodynamics of the two partition processes has, however, shown that they are not analogous and that linear relationships can be expected to have different slopes for structurally unrelated compounds. In this study a set of literature lipid normalized BCF (BCF_L) values of chlorbenzenes (CBs) for rainbow trout and polycyclic aromatic hydrocarbons (PAHs) forDaphnia was put together with literature K_ow values. The slopes of the regression lines for log BCF_L versus log K_ow for the two groups of compounds proved to differ significantly in a statistical test using analysis of variance (ANOVA). The difference, which is of significance for estimates of BCFs in environmental modelling of these types of compounds, is explained by the differences in chemical structure of the two groups of compounds.     

Sedimentation and sulfate reduction under a mussel culture

The sedimentation and dissimilatory sulfate reduction under a blue-mussel culture were quantified in order to gain information on the environmental impact of intense mussel farming. The sedimentation rate (3 g C·m^-2·d^-1) under a culture is nearly three times higher than at a nearby reference station. A build-up of sediment rich in organic material and sulfide takes place under the mussels. At 15°C the sulfate reduction rate was 30.5 mmol SO ₌ ⁴ ·m^-2·^-1 in the upper 10 cm of the mussel sediment. The increase in sedimentation under a mussel culture and the consequent effects should be considered when establishing mussel farms.     

Buoyancy of natural populations of marine phytoplankton

Buoyancy of natural populations of marine phytoplankton was studied in a fjord in western Norway during the diatom bloom and in autumn. The study was carried out under approximate in situ conditions by means of an apparatus described in the paper. During the spring bloom, positive buoyancy was observed only once. Sinking rates of individual fractions ranged from 0 to more than 9 m day^-1, and the mean sinking rates of the total chlorophyll content from 0 to at least 2. 2 m day^-1. The highest rates occurred in the post-bloom period, while sinking appeared negligible from the onset of the bloom up to its culmination. In autumn, the population was dominated by small, flagellated cells. Positive buoyancy, or upward migration, was then observed in two out of three experiments.     

Laboratory rearing of Sepiolinae (Mollusca: Cephalopoda)

Five species of Sepiola and Sepictta were reared in the laboratory from egg to adult size. Spawning was achieved in 3 species of Sepiola after 5 to 7 months. The growth rate of the species reared did not depend upon temperature, which ranged from 12.5° to 20°C. A fairly constant size increase (2.5 mm mantle length/month) was observed in Sepiola during the 5 months after hatching. In Sepietta, the same growth rate was observed until the fourth month after hatching, when it increased to the rate of 5 mm mantle length/month.Laboratoire associé au C.N.R.S.     

Green liquor dregs as an alternative neutralizing agent at a pulp mill

Green liquor dregs is the biggest waste fraction at sulphate pulp mills. It is commonly landfilled. Here we demonstrate that the utilization of green liquor dregs as a neutralizing agent for acidic wastewaters is a potential alternative and an environmentally friendly method in contrast to its landfill disposal. The liming effect value of 39.6% for green liquor dregs, expressed as Ca equivalent, is similar to the liming effect value of 38% of a commercial limestone product. In addition, the pH value of 10.7 indicates a strong liming effect.