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.