Distribution of Heavy Metals and Metalloids in Soil Catenas of the City of Serpukhov
The features of the lateral and vertical distribution of the total contents and and concentrations of mobile (AAB extract at pH 4.8) forms of heavy metals and metalloids (<b>HMMs</b>) in two heterogeneous soil-geochemical catenas of the city of Serpukhov (Moscow region) located in the industrial and park-recreational land-use zones, were studied. The total content of V, Co, Ni, As, Mo, Sb, W, Fe is characterized by the median-accumulative type of lateral differentiation with maximum accumulation coefficients L of 2–2.4. HMMs accumulate at chemisorptive, biogeochemical, and alkaline lateral geochemical barriers. Lateral differentiation of mobile HMMs (L 0.1–7.4) in the catenas is more contrasting than that of total HMMs (L 0.2–2.4). The change in redox conditions has the greatest effect on the content of mobile HMMs; therefore, maximum concentrations of mobile forms of Mn, Zn, Cu, and Cr in the “park-recreational” catena and Fe and Mn in the “industrial” catena are confined to super-aquatic landscapes. The main types of vertical differentiation of the total HMMs content for the “park-recreational” catena are: uniform (V, Cr, Co, Ni, Cu, Zn, Sr, Mo, Sb, W) and regressive, with a maximum in the lower horizon (Bi, Pb, As, Ba). The “industrial” catena is characterized by the surface-accumulative distribution of the total content of Cu, Zn, Cd, Sn, Pb, Sb, and Bi. With an increase in anthropogenic load, the contrast of lateral and vertical distribution of HMMs increases by 1.3–2.2 times.