Alexander Timofeevich Savichev

Expression of the total chemical analysis in the form of oxides has significant drawbacks: this conditional form does not correspond to the actual content of soil minerals. Oxide form distorts the view of the relationship between the different elements in the soil. It is obvious that the total chemical composition should be expressed in the form of elements including oxygen - the element with the maximal Clarke. Thus it is necessary to consider the amendment on oxygen loss on ignition of the soil. The studied soil on amendments to oxygen can be divided into three groups. For spodosols of Russian plain after amendments oxygen content increases slightly and total chemical composition of practically does not change. For vertisols of southern Siberia after amendments oxygen content increases by 3 - 4%. Not accounting for this fact leads to a noticeable error in the content of K. For oxisols in Norfolk Island with a high proportion of unstable gibbsite after amendments content O increases by 7 - 8%. This leads to a noticeable error in the contents: O, Al, Fe and Ti in particular. For oxisols the amendment of oxygen is required.

In hydromorphic soils are important not only sustainable Fe-minerals, defined traditionally in dried soil, but also unstable Fe-minerals, changing the colors of the clay after extracting the sample fr om the soil, as well as — weakening gley signs in the dry season. New indicators are offered for the additional characteristic of Fe-minerals. The first is that it characterizes the interaction of active Fe-minerals with colloids, it is index I: I = CEC/Fe (free), wh ere CEC is the cation exchange capacity. The second indicator is the change in the gley color after drying, assessed by the change in the redness Да*. In Fe-enriched, reduced gley Gr with a low index value (/0,1) and a strong increase Aa* ~ 9 after drying, the green rust is transformed into a brown lepidocrocite. During the humidity decrease, the transition of the reduction gley to the oxidized gley is accompanied by a change in the composition of the green rust: the transformation of fougerite into a trebeurdendite: Fe-ephemera with a higher degree of Fe oxidation and the growth of Да* ~ 3. When oxidized gley Go with the index I = 2—8 is dried, the slow Да* growth is caused by the inhibition of Fe-hydroxide crystallization by colloids. In the “de-ironed” gley Gdf with a high value the index 1= 6—27, the lack of red growth (a* « 0) on drying, is probably due to the Fe clay minerals inertia.

The laboratory study of the solid phase of salted peat by X-ray fluorescence analysis revealed the presence of some halogen-organic compounds. Cl-organic compounds were formed in one third of peat samples, while their share is small: 14-15% of the total Cl. On the contrary, Br-organic compounds are formed more often and Br_org proportion is higher: from 12 to 23% of total Br. Relatively weak development of halogenisation of the organic matter in salted peat bog is explained by the recovery conditions that prevent the synthesis of halogen-organic compounds. In X-ray diffraction analysis of peat ash, errors are possible, both due to the growth of minerals, and due to incomplete identification of the number of phases in high-ash peat samples. The second type of error can be corrected using data on the content of chlorine in peat by X-ray fluorescence analysis. In the characteristic of peat bog contamination, in addition to salt profiles in the solution, it is necessary to determine the number and composition of halogen-organic compounds, some of which have herbicide properties.

We used sequential static chemical extraction methods for studying soil pollution with heavy metals. This allowed determining the amount of metals extracted with this reagent. The new equipment for dynamic extraction of HM and obtaining extractograms, opens up additional possibilities: to determine the number of particles’ groups that differ in resistance to this reagent and to determine the statistical indicators of each group of particles. The technique for decrypting extractograms is based on their deconvolution into a series of asymmetric Gaussians corresponding to a separate group of particles – carriers of HM. The statistical indicators of Gaussians include the relative stability of each group of particles to this reagent, their dispersion D, asymmetry As, and excess Ex. Statistical indicators of Ca-Mg particles of HM carriers in urban soils show a high heterogeneity in the resistance of particles to acetic acid compared to particles in non-urban soils. The probable reason for the difference between urban and non-urban soils is a different composition of Ca-Mg minerals: , most Ca-Mg minerals in non-urban soils are carbonates. Urban, initially carbon-free soils are contaminated with Ca-Mg-containing construction waste: cement, lime and asbestos, and also contain secondary carbonates formed from Ca-Mg-waste. Urban acetic soluble pollutants belong to the following groups of minerals: technogenic hydroxides, silicates and aluminates of calcium and magnesium, which greatly distinguishes their chemical properties from the properties of carbonates. The abundance of pollutant forms as carriers of HM determines the diversity and heterogeneity of groups of particles soluble by acetic acid in urban soils.

New indicators of lanthanide affinity for carrier phases in the soil, based on the rationing of lanthanide concentrations by their soil clarks, are proposed. This made it possible to obtain an original indicator of the affinity of lanthanide A_LN to carrier phases in soils. The indicator of affinity of lanthanide A_LN showed its advantage over the accepted pC_Ln index in the analysis of Russian and Swedish soils.