Alkylation of Benzene with Technical Fraction Propylene - Propane Over Modified B-(Al)-HZSM-5 Catalysts

Benzene alkylation with propylene - propane technical mixture over B-(Al)-HZSM-5 zeolite, as solid acid catalyst has been studied. It was found that izopropylbenzene (IPB) formation associate with a low level of byproducts, e.g., n-propylbenzene (NPB) and di-izopropylbenzenes (DIPB) as result of the inherent multiple competing reactions. Under the specific conditions in the alkylation of benzene with propylene -propane mixture, the maxim yields of IPB (% wt.) and the IPB selectivity based on benzene reaction (wt.%) were 86, 87 and 87.0 %.

THE STUDY OF INTERACTIONS IN THE SYSTEM OF ”BORIC ACID-UREA” BY THE METHOD OF INFRARED-FURIE SPECTROMETRY

The possibility of usage of method of infrared spectrometry with Furie transformation for the investigation of the depth of the flow of interactions in the system of ”boric acid-urea” is investigated. It is shown that infrared spectrum reflects even the smallest changes of the structure of the given system very good. The investigation of the influence of temperature, duration of heating, and correlation of components of the technical mixture ”boric acid-urea” on the process of their interaction is carried out.

Nonylphenols degradation in the UV, UV/H2O2, O3 and UV/O3 processes – comparison of the methods and kinetic study

This paper describes the results of experiments on the decomposition of selected nonylphenols (NPs) in aqueous solutions using the UV, UV/H2O2, O3 and UV/O3 processes. The goal of the research was to determine the kinetic parameters of the above-mentioned processes, and to estimate their effectiveness. These substances were selected because of their ubiquitous occurrence in the aquatic environment, resistance to biodegradation and environmental significance. As a result of the experiments, the quantum yields of the 4-n-nonylphenol (4NP) and NP (technical mixture) photodegradation in aqueous solution were calculated to be 0.15 and 0.17, respectively. The values of the second-order rate constants of the investigated compounds with hydroxyl radical and NP with ozone were also determined. The estimated second-order rate constants of 4NP and NP with hydroxyl radicals were equal to 7.6 × 108–1.3 × 109 mol−1 L s−1. For NP, the determined rate constant with ozone was equal to 2.01 × 106 mol−1 L s−1. The performed experiments showed that NP was slightly more susceptible to degradation by the UV radiation and hydroxyl radicals than 4NP. The study demonstrated also that the polychromatic UV-light alone and also in combination with selected oxidizers (i.e. hydrogen peroxide, ozone) may be successfully used for the removal of selected NPs from the aqueous medium.

Persistent organic pollutants (PCBs and OCP) in air and soil from Ulaanbaatar and the Lake Hovsgol region, Mongolia

The investigations of POPs in soil and air in three urban and rural sites of the Mongolia are presented. The POPs distribution in air repeats the POPs distribution in soil on the area investigated. The POPs levels in soil and air are lower than maximum permissible concentrations (MPC) and preliminary permissible concentrations (PPC) of PCBs and OCP accepted in Russia. POPs levels in Mongolian soil obtained in the investigation are comparable with those from background areas of the world. POPs levels in Mongolian air are in the frame of concentrations found in the world. The PCB homological pattern in soil near electric power station in Ulaanbaatar is close to homological pattern in PCB technical mixture (Sovol or Arochlor 1254). The homological patterns in soil from other sites changed due to the redistribution of PCB congeners in the environment. The ratio of DDT and its metabolites indicates fresh entrance of DDT in the environment of Mongolia due to the atmospheric transboundary transport from countries using DDT (China, India) or from local agricultural sources. Hazard indexes in result from human exposure with POPs in soil and air are lower by 2-4 orders than 1 that denotes the possible default of disturbances in target organ and system. CR under the same scenario corresponds to the first diapason that is taken by population as negligible risk, not differ from usual everyday risks. Such risks don’t require additional measures for the reducing of risks and their levels are a subject of periodical control. The necessity of additional investigation of POPs distribution and the fate in Mongolian environment is indicated.DOI: http://dx.doi.org/10.5564/mjc.v12i0.176 Mongolian Journal of Chemistry Vol.12 2011: 69-77