International Scientific Journals
of Scientific Technical Union of Mechanical Engineering "Industry 4.0"

This study examines a combined remediation strategy that integrates humic acids derived from Ukrainian lignite with oat (Avena sativa L.) phytoremediation to restore soils contaminated with heavy metals as a result of military activities in Ukraine. Humic acids were extracted using an energy-efficient hydrocavitation method and applied to artificially contaminated peat at two dosages (1:5 and 1:10). The amendments markedly reduced the mobility and extractable concentrations of Pb, Cd, Ni, Cu, and Zn, with total decreases ranging from about 25% in the untreated control to nearly 47% under the highest humate application rate. Improved soil structure and stimulated root development contributed to enhanced plant tolerance and greater biomass production. Metal accumulation occurred predominantly in roots (68–90%), while only 10–32% was translocated into biomass, indicating effective stabilization within the soil–plant system and minimized risks for trophic transfer. These findings demonstrate that hydrocavitation-extracted lignite humates substantially reinforce phytoremediation efficiency and represent a scalable, low-cost, and environmentally sustainable solution for rehabilitating conflict-affected agricultural soils.

Pressures exerted on the soil ecosystem due to its exposure to Zn evoke a real and aggravating effect on the quality of life. Greenhouse pot experiments were conducted to study the effects of mineral amendments (zeolite and bentonite) on selected physico-chemical properties of soil, L. perenne growth, Zn accumulation in plant and soil. The contents of Zn in the plants and soil were determined using the method of spectrophotometry. Zn contents in the tested parts of L. perenne differed significantly in the case of applying amendments to the soil, as well as increasing concentrations of Zn. The greatest average above-ground biomass was observed when zeolite were amended into the soil. Bentonite also caused significant increases in Zn concentrations in the roots. Bentonite and zeolite were shown to be the most effective and decreased the average Zn contents in soil.

Heavy metal accumulation potential in the biomass and different plant parts of the selected species of energy crops cultivated on contaminated soil was evaluated. Phytoextraction potential, biomass yield and qualitative parameters of bioenergy plants grown on heavy metal contaminated soil has been measured. Finally heavy metal influence on biomass utilization possibilities, energy recovery and further safe use of the rest products has been evaluated. Demonstrated possibilities to grow bioenergy plants on moderately contaminated soil could increase the use of marginal lands, decrease land use competition between food and liquid biofuels and provide options for a gentle and cost-effective remediation.