Biochar activation methods have attracted extensive attention due to their great role in improving sorptive properties of carbon-based materials. As a result, chemically modified biochars gained application potential in the purification of soil and water from xenobiotics. This paper describes changes in selected physicochemical properties of high-temperature wheat-straw biochar (BC) upon its deashing. On the pristine and chemically activated biochar (BCd) retention of five pesticides of endocrine disrupting activity (carbaryl, carbofuran, 2,4-D, MCPA and metolachlor) was studied. Deashing resulted in increased sorbent aromaticity and abundance in surface hydroxyl groups. BCd exhibited more developed meso- and microporosity and nearly triple the surface area of BC. Hydrophobic pesticides (metolachlor and carbamates) displayed comparably high (88–98%) and irreversible adsorption on both BCs, due to the pore filling, whereas the hydrophilic and ionic phenoxyacetic acids were weakly and reversibly sorbed on BC (7.3 and 39% of 2,4-D and MCPA dose introduced). Their removal from solution and hence retention on the deashed biochar was nearly total, due to the increased sorbent surface area and interactions of the agrochemicals with unclogged OH groups. The modified biochar has the potential to serve as a superabsorbent, immobilizing organic pollutant of diverse hydrophobicity from water and soil solution.

Since biochar is considered to be a significant source of carbon, in this work we have evaluated the changes in soil organic matter (SOM) and soil structure due to application of biochar and biochar with N fertilization, and have considered the interrelationships between the SOM parameters and...

During the research, cumulative properties of conifer needles P. armandii, P. banksiana, P. mugo, P. nigra, P. sylvestris and P. wallichiana in reference to Cu, Ni, Mn, Fe, Zn and Cd were analysed, and the factors which have an impact on the chemical composition of the bark of those species were identified. During the study, the age of needles and the content of the examined components in soil was taken into consideration. The content of metals in the needles varied, depending on a species and the age of the coniferous needles. In most cases, a higher level of content of those metals was determined in 2 years old needles, except for Cu and Zn (P. banksiana) as well as Zn (P. nigra), in which case, higher concentration of metals in 1 year old needles was determined. The obtained results indicate that the heavy metals’ concentration in the samples of needles was relatively low, except for Ni (P. armandii, P. sylvestris, P. wallchiana) and Cd (P. armandii, P. banksiana), which showed higher levels. Among the examined elements, Mn was accumulated in the largest volume in the needles of P. banksiana, Fe and Cu in the needles of P. wallchiana, Ni in the needles of P. sylvestris, Zn in the needles of P. nigra and Cd in the needles of P. armandii. The bark samples represented a clearly acidic reaction, with pH levels from 3.7 (P. sylvestris) to 4.9 (P. armandii). The highest quantities of Mn, Fe, Cu and Cd were accumulated by the bark of P. armandii, Ni in the bark of P. sylvestris and Cu in the bark of P. mugo.

Soil organic matter (SOM) is considered to be the most important part of the soil. C and N and their forms are most often used to evaluate SOM. In the last decades, C indices have begun to be used to assess soil quality for C changes in SOM due to the different soil management. Since C cycle is...