Ecological Dangers of Chemical Contamination of Urban Areas Soils: Casestudy of Tomsk

The elemental composition of soils in Western Siberia industrial center – Tomsk city is studied. The content of 28 elements in soils of the four administrative districts is determined by the instrumental neutron activation analysis method. The value of calculated total pollution index indicates a high degree of soil contamination, and dangerous levels of human health risk. The main contributors to the total pollution index value are elements: Tb, Br, Sb and Ta. The districts were ranked by the accumulation level of some elements, and it is shown that increased concentration values are confined to industrial enterprises and fuel cycle. The specificity of city districts soil cover is the increased values of relative to the city average values of several elements contents: Kirovsky district- Na and Ba, Oktyabrsky - Hf, Sc, Tb, Sm, La, Ce, Yb, Lu, and Br, Leninsky - Ca, Rb, Sr. The main sources of chromium and barium in the Tomsk city environment are analyzed

Optimal Fractionation of Products of Refining Straight-run Gasoline on Zeolite Catalyst with Account of its Deactivation

Flowsheet of industrial refining straight-run gasoline on zeolite catalyst includes the necessary stage of fractionation of conversion products to produce commercial gasoline, gas and heavy residue. Changes in qualitative and quantitative compositions of the catalytic conversion products under catalyst deactivation require current parametrical optimization of this stage. Objective functions that take into account catalyst deactivation and the constrains depending on the requirements for product quality and equipment specifications were developed. Optimal conditions were found to differ significantly from those designed for fresh catalyst