143ChemInform Abstract The preparations of the (5-tetrazolyl)tri-, -di-and -mononitromethanes and their tetrazolyl-1-and tetrazolyl-2-methyl derivatives -i.e. the compounds (II), (III), (V), (VII), (IX) and (XIX) -are described. The reactions of the derivatives (VII), (IX) and (XIX) with diazomethane according to method A) proceed via methylation of the nitrogen atoms of the heterocycle or the oxygen atoms of the nitro groups to afford the corresponding products. No methylation of the exocyclic carbon atom is observed in any of the reactions. The mixture of the isomeric nitronic acid methyl esters (XII) and (XIII) spontaneously yields the bis(5-tetrazolyl)oxadiazole derivative (XV).
Processes of aerobic biological puri®cation by pilot bio®lters of chemical enterprise sewage (COD 14 g dm )3 ) and recirculating waters of atomic power station contaminated with oil products (10±270 mg dm )3 ) have been investigated. Fibrous materials were used as biomass carriers. These have been manufactured from thermoplastics (polyethylene, polypropylene, polyamide) by melt-blowing technique. New polymeric ®brous carriers (PFC) of optimized composition, structure and shape are superior to common carriers (claydite, porous ceramics, foamed polyurethane) by speci®c sorption capacity towards complex associations of microorganisms. In contrast to bio®lters ®lled with claydite, those ®lled with PFC are characterized by accelerated transfer to stationary working regime, above 90% of biopuri®cation ef®ciency of high-loaded industrial wastewaters and process stability at toxic actions of biomass, as well as reduced aero-and hydrodynamic resistance of the ®ltering biolayer. Prospects of improving the bio®lter operation are discussed, in particular, by means of carrier modi®cation: ®ber ®lling with magnetic or electroconductive substances, adhesive ®xation of adsorbents on the ®bers, etc. Such PFC can be related to a promising generation of biosorbents and biomass carriers.
The probability of a series of substituted 1,2,4-tri-and tetrazole compounds and by these modi®ed polymer ®lm materials to inhibit the process of microbiological corrosion of metals has been investigated. Fungitoxicity of the studied compounds and materials has been observed for Aspergillus, Penicillium and Trichoderma fungi whose metabolites initiate corrosion of ferrous and nonferrous materials. For Thiobacillus ferrooxidans as an example, the bactericidal properties have been studied and azoles have been proven to suppress test-culture growth in culture medium. A comparative analysis of fungi and bactericidal activity of the studied compounds has been carried out. According to experimental results of kinetics of modi®er desorption from the polymer matrix, the microbicidal effect of modi®ed ®lms is determined along with the corrosion inhibitor (CI) biocidal properties by its volatility and the intensity of the liquid phase (plasticizer + CI) syneresis from the material bulk. It has been concluded that there are fair prospects of application of azoles and by azoles modi®ed materials as means of protection against both microbiological and electrochemical corrosion.
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