Gentoxische Substanzen in Wässern

The contamination of waste waters with genotoxic compounds has raised concern about the toxicological impact on man and ecosystems. Some epidemiological studies showed a correlation between contamination of water with genotoxic compounds and incidence of cancer in man, fish, and mussels. This review of published literature summarizes results of the mutagenic potential of waste water from various industries. The Ames assay is frequently used as test system for mutagenicity of organic and inorganic compounds. Some investigations tried to identify the sources of mutagenic contamination. A variety of organic (e.g. nitroaromatic compounds, polycyclic aromatic hydrocarbons, azo-dyes, chlorinated hydroxyfuranes) and inorganic (e.g. heavy metals) mutagenes were identified but it was not possible to attribute the whole mutagenic potential to analytically identified compounds. Due to the lack of data it is presently not possible to perform a risk assessment for humans.     

Aspects of 14CO2-fixation by endosymbiotic rhodoplasts in the marine opisthobranchiate Hermaea bifida

When the marine opisthobranchiate slug Hermaea bifida Mont. is incubated in a H¹⁴CO ₃ ^- -seawater medium in the light, a considerable net gain of ¹⁴C-assimilates is observed. Electron microscopic control provided evidence that this ¹⁴C-fixation is due to photosynthesis by chloroplasts (=rhodoplasts) endosymbiotic in the cells of the digestive gland of the slug. After thin-layer chromatographic analysis various ¹⁴C-labelled photosynthates could be traced. The assimilate pattern of the rhodoplasts is compared with that of the marine red alga Griffithsia flosculosa (Ellis) Batt., from which the plastids are acquired by feeding. The nutritional relationship of this endosymbiosis is discussed, with emphasis on the occurrence of functional chloroplast endosymbioses among the eolidiform species of the Sacoglossa.     

An LCA model for waste incineration enhanced with new technologies for metal recovery and application to the case of Switzerland

A process model of municipal solid waste incinerators (MSWIs) and new technologies for metal recovery from combustion residues was developed. The environmental impact is modeled as a function of waste composition as well as waste treatment and material recovery technologies. The model includes combustion with a grate incinerator, several flue gas treatment technologies, electricity and steam production from waste heat recovery, metal recovery from slag and fly ash, and landfilling of residues and can be tailored to specific plants and sites (software tools can be downloaded free of charge). Application of the model to Switzerland shows that the treatment of one tonne of municipal solid waste results on average in 425 kg CO₂-eq. generated in the incineration process, and 54 kg CO₂-eq. accrue in upstream processes such as waste transport and the production of operating materials. Downstream processes, i.e. residue disposal, generates 5 kg CO₂-eq. Savings from energy recovery are in the range of 67 to 752 kg CO₂-eq. depending on the assumptions regarding the substituted energy production, while the recovery of metals from slag and fly ash currently results in a net saving of approximately 35 kg CO₂-eq. A similar impact pattern is observed when assessing the MSWI model for aggregated environmental impacts (ReCiPe) and for non-renewable resource consumption (cumulative exergy demand), except that direct emissions have less and no relevance, respectively, on the total score. The study illustrates that MSWI plants can be an important element of industrial ecology as they provide waste disposal services and can help to close material and energetic cycles.