ПРИМЕНЕНИЕ ГУМИНОВЫХ КИСЛОТ ДЛЯ ПОВЫШЕНИЯ УСТОЙЧИВОСТИ РАСТЕНИЙ К ЗАГРЯЗНЕНИЮ СУБСТРАТА ЗЕЛЕНЫХ КРОВЕЛЬ ТЯЖЕЛЫМИ МЕТАЛЛАМИ

APPLICATION OF HUMIC ACIDS TO INCREASE RESISTANCE OF GREEN ROOF PLANT COMMUNITY TO HEAVY METAL CONTAMINATION

Green roofs provide several ecosystem services, but due to the accumulation of atmospheric dust, they can be contaminated with heavy metals, which can reduce plant growth and pollute water runoff. In this study, we tested the original humic acids (HAo) isolated from black alder lowland peat and modified (HAmod) by reduction with sodium borohydride. The targeted chemical modification increased the phenolic group content in HAmod by 20% compared to HAo, increasing the ability of HAmod to reduce the toxic effect of heavy metal ions by binding them into non-toxic complexes. Testing with the “Ecolum” system showed that HAo and HAmod at concentrations of 50 and 100 mg L-1 did not have a toxic effect on microorganisms and can be used to reduce the toxicity of heavy metal ions. The addition of 50 mg L-1 HAmod reduced the toxicity of Cd2+ to an acceptable level, and the toxicity index for Zn2+ decreased by 2 times. The content of phenolic compounds in the test object (garden cress (Lepidium sativum)) grown on gray forest soil contaminated with cadmium (10 mg·kg-1) and zinc (100 mg·kg-1) ions decreased after the application of HAmod, indicating a reduction of plant stress. HAmod stimulated the root system of garden cress compared to the control; the total biomass increased by 90–120% compared to the substrate contaminated with Cd2+ and Zn2+ without the addition of HAmod. Thus, HAmod can be used to reduce the toxicity of heavy metal ions in substrates of green roofs. © 2025, Altai State University. All rights reserved.