**Acknowledgements**

*Applications of Biochar for Environmental Safety*

been found the most effective for this function among all the surfactants tested. The observed benefit of CTAB was attributed to the (pre)treatment of CPE by means of "erosion effect." The same modifier effect was observed for NaFLUFA, as could be

*The main oxidation peak of NaFLUFA and the effect of the presence of cetyltrimethylammonium bromide* 

*(CTAB) surfactant in the solution and phosphate buffer baseline (PBS).*

Typical experimental and instrumental conditions of NaDCF and NaFLUFA voltammetric determination (DPV) had included the following parameters: supporting electrolyte 0.1 M PBS + 0.1 mM CTAB, potential scan from +0.2 to 1.2 V vs.

Sorption experiments were carried out in a magnetically, at 400 rpm, stirred 250 mL round-bottomed flasks at 25°C using Starfish equipment installed on an electromagnetic stirrer Heidolph-Hei-Standart with a temperature sensor Pt1000. The appropriate quantity of biochar was added to 100 mL of synthetic wastewater (possibly after the addition of R4NCl(s)). In performed kinetic experiments (**Figures 2**, **3**, **5**, **6**, and **8**), the initial concentration of NaDCF in synthetic wastewater was 25 mM (8 g NaDCF/L and pH = 8.7), the concentration of FLUFA in synthetic wastewater was 10 mM NaFLUFA in 12 mM NaOH (2.81 g FLUFA/L and pH = 10.3), and the concentration of MB9 was 10 mM (5.5 g MB9/L). In a subsequent comparative study for the construction of adsorption isotherms (**Figures 10–12**), the concentrations of contaminants in starting aqueous solutions were 0.25–8 g NaDCF /L, 0.25–7 g -FLUFA/L, and 0.5–5 g MB9/L (for additional information see the text and Figures and Tables in the previous chapters). Stirred suspensions were immediately filtered and analyzed after an appropriate time

**260**

period.

seen in **Figure 14**.

**Figure 14.**

ref., and scan rate of 50 mV/s.

**7.5 Sorption experiments**

This work was funded by the Faculty of Chemical Technology, University of Pardubice, within the financial support for the excellent team (Chemical Technology Group), Specific university research—grant No. A1\_FTOP\_2020\_001, and by the Ministry of Agriculture of the Czech Republic—project QK1820175 and QK1910056.
