Verteilungskoeffizienten chlorierter Kohlenwasserstoffe zwischen Muskulatur und Leber bei Fischen

Measured partition coefficients (KL_M/L) related to lipid-concentrations between the muscle (C_ML) and liver (C_LL) tissue of two fish species (Abramis brama, Zoarces viviparus) exhibit nominal values of unity according the relationship KL_M/L=C_ML/C_LL=1 for persistent compounds such as highly chlorinated PCB and values above one for degradable compounds for example chlorinated cyclohexanes or DDT. The corresponding theory is presented. The relationship holds for samples for single fish as well as for pooled samples.     

Bioassay zur Bestimmung von TCDD-Toxizitätsäquivalenten (TEQ) von Umweltproben und Reststoffen

Polychlorinated aromatic hydrocarbons (HAH) like 2,3,7,8-tetrachloro-p-dioxin (TCDD) elicit a multitude of toxic and biological effects. A common trait of these substances is their affinity for a cytosolic receptor protein and the subsequent induction of the synthesis of several gene products, including cytochrome P450 1A1 (CYP 1A1). In this publication we present a bioassay to determine the induction of CYP 1A1 as a sum parameter for the total toxic potential of critical halogenated compounds in complex environmental matrices. In order to eliminate compounds like polycyclic aromatic hydrocarbons (PAH) and naturally occurring substances which might interfere with the bioassay we developed a simple cleanup procedure. TEQ values derived from bioassay are in good agreement with those obtained from chemical analysis. This bioassay in combination with the simplified “single column” clean up represents a cost and time effective alternative to chemical analysis for the screening of large numbers of environmental matrices.     

Toxiwasp∗

TOXIWASP combines most of the kinetic structure of EXAMS 2 with the transport capabilities of WASP (Water Analysis Simulation Program). TOXIWASP uses variable chemical degradation rates from chemical properties and the environmental conditions of the aquatic ecosystem. These rates are reduced from pseudo first‐order rates to first‐order rates including the processes hydrolysis, biotransfor‐mation, phototransformation, oxidation, and volatilisation. Assuming ultimate local equilibrium, and using a chemical dependent partition coefficient as well as spatially varying environmental carbon fractions, sorption onto sediments and biomass is calculated. Environmental alternations could be specified in any time scale by providing monitoring data.

TOXIWASP generates total sediment and chemical concentrations every time step in every segment, including surface water, subsurface water, surface bed and subsurface bed. Advection, dispersion, mass loading, sedimentation, and scour affect sediment concentration in the water column and in the bed sediment concentrations depend on burial and erosion. In addition chemical concentrations are influenced by degradation, sediment‐water dispersion, and percolation. Lateral transport of chemical within the bed is neglected and transport data are not calculated in the program. TOXIWASP is developed to model stratified lakes, reservoirs, large rivers, estuaries, and coastal waters. As for EXAMS 2 (Burns et al.²) the TOXIWASP user has to accept the model's inability to connect the water body to a chemically contaminated atmosphere.     

Simultaneous monitoring of profiles of polycyclic aromatic hydrocarbons in contaminated air with semipermeable membrane devices and spruce needles

Gaseous emissions of combusted electronic scrap, PVC, carpet and wood were monitored for polycyclic aromatic hydrocarbons (PAHs) by simultaneous use of semipermeable membrane devices (SPMDs) and shoots of spruce needles (Picea abies). It was found that phenanthrene, acenaphthylene and fluorene were the dominating PAHs in all samples. SPMDs and needles mainly sequestered PAH associated with the vapor phase. Particle-bound PAHs were only detected in small amounts, at which the needles tended to uptake more of these compounds in comparison to the SPMDs. Nevertheless, the logarithm of the concentrations of PAHs analyzed in both passive samplers after the same sampling period exhibited a significant linear correlation with correlation coefficients larger than 0.8073. SPMDs and spruce needles can complement each other in passive air sampling for compounds with a preference to the gas phase rather than aerosols.     

Polychlorinated organic compounds (PCOCs) in waters, suspended solids and sediments of the Yangtse River

The contamination levels of polychlorinated organic compounds (PCOCs) in waters, suspended solids and sediments of the Yangtse River (Nanjing part) were analyzed in this paper. Their concentrations determined by GC/MS were very low in comparison with those in European River. The average concentration of total HCH (alpha-HCH, beta-HCH, gamma-HCH) was much higher than that of other PCOCs in all waters, which made up 65% of total amount of PCOCs. Due to the complete dilution and mixture of pollutants in the mighty Yangtse River, the content of PCOCs at each sampling station demonstrated very similar spatial pattern for waters and suspended solids. Since the small suspended solid (<0.7 microm) passed through the filter was also considered as dissolved part, the dominant parts of HCHs, PCA and PCBs were found in dissolved phase with percentage proportion of 85-94%, 72-85% and 61-78%, respectively. For DDTs, HCB and PeCB, their contents in dissolved phase were slightly higher than in particulate phase. The contents of PCOCs in sediments were also very low and varied with high fluctuation at different sampling points, indicating the heterogeneous deposition. HCB and its metabolite (PeCB) presented the highest contamination levels among PCOCs in sediments.     

Possibilities and limitations of a comparative assessment of process technologies from a cleaner production point of view

This article presents a method for a comparative assessment of process technologies from a cleaner production point of view as well as the results of testing this method in practice. Based on these results and on an analysis of existing technology information systems, an estimation is made of the general possibilities and limitations of a comparative assessment of process technologies from a cleaner production point of view. Finally, the resulting consequences for the definition of ‘best available techniques' in accordance with the new EC Council Directive Concerning Integrated Pollution Prevention and Control (IPPC) are discussed. This article argues that apart from the difficulties related to the valuation of different kinds of materials and energy a major limiting factor is caused by the fact that the function of a production has to be defined very precisely to enable a comparison between different types of process technologies in sufficient detail.     

Photodegradation of PCDD/Fs adsorbed on spruce (Picea abies (L.) Karst.) needles under sunlight irradiation

Spruce (Picea abies (L.) Karst.) needles were exposed to exhaust gas containing polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs) generated by combustion of polyvinyl chloride, wood, high-density polyethylene, and styrene. Photodegradation of PCDD/Fs adsorbed on spruce needles under sunlight irradiation was studied. The photodegradation of PCDD/Fs follows pseudo-first-order reaction kinetics, with photolysis half-lives ranging between 40 and 100 h. The photolysis rates of PCDF congeners are higher than PCDD congeners with the same chlorinated substitutions. Higher chlorinated PCDD/Fs tend to photolyze slowly. The wax components in spruce needles may act as proton donors and accelerate the photolysis rate. C-Cl cleavage through the addition of protons to PCDD/F molecules may be an important route for PCDD/Fs photodegradation.     

Nitrifying community analysis in a single submerged attached-growth bioreactor for treatment of high-ammonia waste stream.

This study investigated the nitrifying community structure in a single-stage submerged attached-growth bioreactor (SAGB) that successfully achieved stable nitrogen removal over nitrite of a high-strength ammonia wastewater. The reactor was operated with intermittent aeration and external carbon addition (methanol). With influent ammonia and total Kjeldahl nitrogen ranging from 537 to 968 mg/L and 643 to 1510 mg/L, respectively, 85% nitrogen removal was obtained, and effluent was dominated by nitrite (NO2-/NOx > 0.95). Nitrifying community analysis using fluorescence in situ hybridization (FISH), with a hierarchical set of probes targeting known ammonia-oxidizing bacteria (AOB) within beta-proteobacteria, showed that the AOB community of the biofilter consists almost entirely of members of the Nitrosomonas europaea/eutropha and the Nitrosococcus mobilis lineages. Image analysis of FISH pictures was used to quantify the identified AOB, and it was estimated that Nitrosomonas europaea/eutropha-like AOB accounted for 4.3% of the total volume of the biofilm, while Nitrosococcus mobilis-like AOB made up 1.2%; these numbers summed up to a total AOB fraction of 5.5% of the total volume on the biofilm. Nitrite-oxidizing bacteria (NOB) were not detectable in the biofilm samples with probes for either Nitrospira sp. or Nitrobacter sp., which indicated that NOB were either absent from the biofilters or present in numbers below the detection limit of FISH (< 0.1% of the total biofilm). Nitrite oxidizers were likely outcompeted from the system because of the free ammonia inhibition and the possibility that the aeration period (from intermittent aeration) was not sufficiently long for the NOB to be released from the competition for oxygen with heterotrophs and AOB. The nitrogen removal via nitrite in a SAGB reactor described in this study is applicable for high-ammonia-strength wastewater treatment, such as centrate or industrial wastes.