Mitigation of the Adverse Impact of Copper, Nickel, and Zinc on Soil Microorganisms and Enzymes by Mineral Sorbents

Abstract

Despite numerous studies on the influence of heavy metals on soil health, the search for effective, eco-friendly, and economically viable remediation substances is far from over. This encouraged us to carry out a study under strictly controlled conditions to test the effects of Cu2+, Ni2+, and Zn2+ added to soil in amounts of 150 mg·kg−1 d.m. of soil on the soil microbiome, on the activity of two oxidoreductases and five hydrolases, and on the growth and development of the sunflower Helianthus annunus L. The remediation substances were a molecular sieve, halloysite, sepiolite, expanded clay, zeolite, and biochar. It has been demonstrated that the most severe turbulences in the soil microbiome, its activity, and the growth of Helianthus annunus L. were caused by Ni2+, followed by Cu2+, and the mildest negative effect was produced by Zn2+. The adverse impact of heavy metals on the soil microbiome and its activity was alleviated by the applied sorbents. Their application also contributed to the increased biomass of plants, which is significant for the successful phytoextraction of these metals from soil. Irrespective of which property was analysed, sepiolite can be recommended for the remediation of soil polluted with Ni2+ and zeolite—for soil polluted with Cu2+ and Zn2+. Both sorbents mitigated to the highest degree disturbances caused by the tested metals in the soil environment.

Soil Enzyme Response and Calorific Value of Zea mays Used for the Phytoremediation of Soils Contaminated with Diesel Oil

“…To evaluate the influence of diesel oil (DO), vermiculite (V), and dolomite (D) on the soil's biochemical activity, as well as on the biomass of Zea mays aerial parts and roots, we calculated the indices of oil and sorbent impact using the formulas described in our previous research [69,71]. These data were presented on thermal maps using RStudio 2023.06.0 software [72] with the addition of R 4.2.2 [73] and the gplots library [74].…”

The Effect of Spring Barley Fertilization on the Content of Polycyclic Aromatic Hydrocarbons, Microbial Counts and Enzymatic Activity in Soil

“…The activity of the following soil enzymes was determined in three replicates: dehydrogenases, by the method described by Öhlinger [34]; urease, acid phosphatase and alkaline phosphatase, by the method described by Alef and Nannipieri [35]; catalase, by the method described by Johnson and Temple [36]. Microorganisms were isolated with the serial dilution method following the procedure described in the study by Wyszkowska et al [37]. The procedure for the determination of soil enzymatic activity was presented in the study by Borowik et al [38] and microbial counts.…”

Biochar, Halloysite, and Alginite Improve the Quality of Soil Contaminated with Petroleum Products

“…Its pH ranges from 7.15 to 7.78. A comprehensive characterization of biochar and halloysite was presented in our previous publications [38,39,47], and alginite [17,47] was also previously described.…”

“…This sorbent increases the mobility of anionic toxic elements [34]. Due to its porous structure, biochar can adsorb and retain organic pollutants [35,36], heavy metals [37][38][39], and other harmful compounds [15].…”