Setting the thresholds for heavy metals based on their background & resilience M. Miroshnychenko, Ye. Hladkikh, V. Solovey, O. Lykova NSC “Institute for and Agrochemistry Research named after O.N. Sokolovsky”

INTRODUCTION drying and dissolving the precipi- CONCLUSION tate in 1 n HCl. HM in the The existing approach in Ukraine were determined after burning According to developed method, the maximum to assess the negative effect of a under the temperature 500oС. permissible additions and concentration were cal- certain chemical substance in the Mobile forms of HM in were culated for 4 elements. Depending on soil proper- system “soil-” is still based on measured using extraction of buff- ties, the total content of zinc should be limited from the system of maximum permissi- ered ammonium-acetate solution 120 to 270 ppm, nickel - from 36 to 90 ppm, lead ble concentrations (MPC) and with pH 4,8 by atomic-absorption - from 36 to 76 ppm, copper - from 24 to 64 ppm. doesn’t take into account the soil spectrophotometry. properties. This approach cannot The content of organic carbon was provide reliable protection of envi- measured according to ISO Fig. 1: Average of HM, their accumulation in plants and yield reduction on contaminated soils with different properties ronment, because it does not meet 10694:1995, texture – to ISO/TS modern requirements and world 7892-4:2008, and pH – to ISO 800,000 400,000 best practices. 10390:2006. 90,000 50,000 OBJECTIVES MAIN RESULTS 10,000 6,000 Preliminary division of soils based According to the existing concept, 2,000 on their protective abilities against soil resistance to contamination 0,700 contamination of plants and ground- depends on two criteria: the 0,300 Clay>40%;; pH>5,7 . content in the soil and soil pHKCl, 0,080 Clay<40%;; pH<5,7 which are the most suitable, since 0,040

Ukraine has a very diverse soil there are numerous data on them 0,009 Level of yeild, % from uncontaminated soil Content of heavy metals in eluate/plants, ppm 0,005 cover. Different perennial rocks, in Ukraine. The collected soil sam- Zn Cd Ni Pb Cu Zn Cd Ni Pb Cu Yield hydrothermal conditions, and bio- ples had a wide variability of the Eluates Plants logic cenoses caused the formation main parameters: pH of salt extract, of a wide geochemical environment value of organic carbon content, soil and more than 600 soil varieties. texture. The leaching of HM from Tab. 1: Comparing the protective abilities of soils with different properties against leaching Therefore, it would be advisable to contaminated soils correspond well of HM and their affect to plants group the soils of Ukraine accord- with the aforementioned concept. Average ratio contaminated ing to their distinctive features. The leaching of Zn, Cd, Ni from soils/uncontaminated soils contaminated low-buffered soils Soil Parameters for for for leaching increased in 39-45 times, and lead group of soil properties accumulation changing of METHODOLOGY HM to the and copper – in 12-18 times more HM in the plant eluate The set of soils for research con- than from the high-buffered soils. plants productivity tained 42 samples of different soil The difference in the accumula- 1 pHKCl≤5.7; clay≤40 % 1600 17.4 12 types of Ukraine taken from the tion in plants was smaller and 2 pHKCl≤5.7; clay>40 % 600 12.1 35 0-30 cm layer. Each sample was amounted to 2-3 times for lead 3 pH >5.7; clay≤40 % 36 5.3 125 divided in two parts, the first one and 5 times for nickel. The decrease KCl not contaminated, and the second in oat productivity was also used 4 pHKCl>5.7; clay>40 % 30 4.1 114 one was contaminated by standard as an additional criterion for pollution mixture. The soil of both assessing the soil resilience variants was placed in the vessels Based on the experimental data all Tab. 2: The proposed system of maximum permissible levels for soils with different properties where plants of oats were growing soils of Ukraine were divided in 4 The maximum permissible addition during 30 days. After this, plants groups according their properties Soil Parameters / the maximum permissible were removed from the vessels, and using the value of pH 5.7 and clay group of soil properties concentration of HM, ppm soil has been washed with water in content 40 %. Each of such soil groups Zn Ni Pb Cu the regime of 100 ml per month. (pHKCl≤5.7; clay≤40 %; pHKCl≤5.7; 1 pHKCl≤5.7; clay≤40 % 80/120 24/36 24/36 16/24 Then, the content of heavy metals clay>40 %; pHKCl>5.7; clay≤40 %, and 2 pHKCl≤5.7; clay>40 % 100/150 30/58 30/43 20/40 (HM) (Cd, Zn, Ni, Pb, Cu) was mea- pHKCl>5.7; clay>40 %) unites several sured in eluates, plants and soils. soils types and occupies the large 3 pHKCl>5.7; clay≤40 % 135/180 40/52 40/52 26/34

The eluates were analyzed after area in Ukraine. 4 pHKCl>5.7; clay>40 % 200/270 60/90 60/76 40/64

GLOBAL SYMPOSIUM ON SOIL POLLUTION 2 - 4 MAY 2018 | FAO - ROME, ITALY