Carboxin and Diuron Adsorption Mechanism on Sunflower Husks Biochar and Goethite in the Single/Mixed Pesticide Solutions

Abstract

The study focused on the adsorption mechanism of two selected pesticides: carboxin and diuron, on goethite and biochar, which were treated as potential compounds of mixed adsorbent. The authors also prepared a simple mixture of goethite and biochar and performed adsorption measurements on this material. The adsorbents were characterized by several methods, inter alia, nitrogen adsorption/desorption, Boehm titration, Fourier transform infrared spectroscopy and X-ray photoelectron spectroscopy. The adsorption study included kinetics and equilibrium measurements, in the solution containing one or two pesticides simultaneously. The adsorption data were fitted to selected theoretical models (e.g., Langmuir, Freudlich, Redlich–Peterson, pseudo first-order and pseudo second-order equations). Based on the obtained results, it was stated that, among all tested adsorbents, biochar had the highest adsorption capacity relative to both carboxin and diuron. It equaled 0.64 and 0.52 mg/g, respectively. Experimental data were best fitted to the pseudo second-order and Redlich–Peterson models. In the mixed systems, the adsorption levels observed on biochar, goethite and their mixture were higher for diuron and lower for carboxin, compared to those noted in the single solutions. The presented results may enable the development of new mixed adsorbent for remediation of soils polluted with pesticides.

Effect of Biochar Modification by Vitamin C, Hydrogen Peroxide or Silver Nanoparticles on Its Physicochemistry and Tetracycline Removal

“…The Redlich-Peterson is a three-parameter isotherm connecting assumptions of the Langmuir and Freundlich isotherms. It assumes that the mechanism of adsorption is hybrid, and it does not follow ideal monolayer adsorption [ 30 ]. The Redlich-Peterson isotherm converges to the Henry law for β = 0 or to the Langmuir form when β = 1.…”

A Stable Fe-Zn Modified Sludge-Derived Biochar for Diuron Removal: Kinetics, Isotherms, Mechanism, and Practical Research

“…The maximal adsorption capacity of diuron by SDMBC600 could reach 17.7 mg/g by fitting the isotherms model. The SDMBC600 had a better adsorption capacity for diuron than previously reported Sunflower Husks Biochar (0.94 mg/g) and Goethite (0.59 mg/g) [ 38 ]. It was also higher than the adsorption capacity of magnetic biochar (11.6 mg/g) prepared by Liu et al [ 20 ] through co-pyrolysis of zero-valent iron nanoparticles and sewage sludge.…”

Study on electrical double layer nanostructure on zeolitic materials’ surface in the presence of impurities of different nature

“…The hydrogen bonds between the -COO − (present in both PAA and DCF molecules) and -NH groups of diclofenac and zeolite hydroxyl groups can be formed. Moreover, hydrophobic interactions of the π-π electron donor-acceptor type can also occur between the aromatic rings of drug molecules and carbon structures on the composite surface (Correa-Navarro et al 2020;Szewczuk-Karpisz et al 2021). The obtained results suggest that the most probable mechanism of DCF adsorption includes the presence of unbound negative groups in the by-surface layer (which has an impact on the observed surface charge reduction) and direct binding of molecules takes place through the hydrogen bridges and hydrophobic interactions (in the case of composite materials containing carbon).…”