The interaction between atrazine and the mineral horizon of soil: a spectroscopic study

Abstract

Purpose In this paper, an attempt was made to explain the long-lasting occurrence of atrazine in soil. Despite the fact that this herbicide has been banned in European Union 10 years ago, it is still detected in the environment. Materials and methods Soil samples (organic and mineral horizon), SiO 2 and Al 2 O 3 sorbents were spiked with atrazine. The ultrasound-assisted extraction coupled with gas chromatography-electron capture detector was performed to establish the atrazine recovery depending on the type of soil horizon and sorbent. Fourier transform infrared spectroscopy (FTIR) analysis was conducted to determine the type of interactions between atrazine and sorbents. Results and discussion The atrazine recovery was lower for the mineral horizon (15%) compared to the organic horizon (63%). This finding suggests an interaction between atrazine and the mineral components of soil. Therefore, attempts have been made to explain atrazine's interaction with the main mineral components of soil, SiO 2 and Al 2 O 3 , and to investigate the influence of pH on atrazine's behaviour in soil. The atrazine recoveries were 86.5 and 10.7% for Al 2 O 3 and SiO 2 , respectively. The obtained results demonstrated that the protonated atrazine exhibits stronger interactions with the soil mineral layer (recovery below 0.1%) in comparison to molecular form of atrazine (recovery 86%). FTIR results suggested interactions between atrazine and SiO 2 . FTIR analysis revealed that 1,3,5-azidine ring interacts with SiO 2 molecule. Conclusions In acidic soil, atrazine remediation is limited, especially if the soil contains minerals with high SiO 2 contents. This situation may cause the long-lasting persistence of atrazine in soil.

Investigation of the Removal of Several Micropollutants Presenting Different Ozone Reactivities from Natural Potable Water Matrix by the Application of Ozonation with the Use of SiO2 and Al2O3 as Catalysts

“…The non-adsorption on alumina suggests that in the case of kaolin, which contains both silica and alumina, the adsorption occurs due to the surface groups of silica. This absence of interaction between alumina and atrazine was also observed by Czaplicka et al [36], who simultaneously confirmed through respective FT-IR measurements that the 1,3,5-azidine ring of the atrazine molecule interacts with the SiO 2 molecules, possibly through the formation of hydrogen bonds between atrazine and silica, such as the one shown in Figure S4.…”

“…Therefore, the contact between the pollutant and the catalyst surface is necessary. The improvement regarding the removal of atrazine only by the presence of SiO 2 (Figure 2) suggests that the organic molecule can be bonded (through hydrogen bonds) with the Si surface, but not with the Al, as other relevant research has also previously reported [36][37][38].…”

Evaluation of Heterogeneous Catalytic Ozonation Process for the Removal of Micropollutants from Water/Wastewater: Application of a Novel Pilot-Scale Continuous Flow System

“…Namely, although ozone is adsorbed on the surface of the catalyst, promoting the formation of hydroxyl radicals, atrazine molecules are not adsorbed on the catalytic surface, indicating that the mechanism of this organic pollutant's degradation mainly includes its oxidation in the liquid phase. A certain improvement, regarding the removal of atrazine, was only observed in the presence of SiO 2 , suggesting that this organic molecule can bind (probably via weak hydrogen bonds) to the Si surface, but not with the other examined materials/catalysts, as the relevant previous research has also reported [38][39][40].…”

Binding and Orientation of Carbamate Pesticides on Silica Surfaces

“…Here, we primarily focus on the interfacial structure and the surface anchoring mechanism of carbaryl on silica using a combination of surface-selective nonlinear vibrational spectroscopy and computational modeling, including molecular dynamics (MD) simulations and ab initio calculations of vibrational spectra. Raman and Fourier transform infrared (FTIR) vibrational spectroscopic methods have been widely applied to study pesticides in bulk solutions and films. ,− Here, we apply vibrational sum frequency generation (vSFG) spectroscopy, an in situ technique particularly suitable for the analysis of molecules at buried interfaces and sensitive to sub-monolayer amounts of adsorbates. ,,− As a coherent nonlinear spectroscopic technique, the vSFG response is highly sensitive to molecular orientation and ordering at the surface, , making vSFG a powerful technique for obtaining detailed chemical information regarding the molecular composition, structure, and interactions of molecules at interfaces. As such, it has become a versatile tool for studies of environmental surfaces and interfaces under ambient conditions ,,− and for revealing structure–activity relationships of surface-immobilized compounds, like antimicrobial coatings. − …”