Atrazine degradation through PEI-copper nanoparticles deposited onto montmorillonite and sand

Abstract

We present the synthesis of new composite materials based on copper nanoparticles (Cu NPs) deposited onto montmorillonite (MK10) and quartz sand, for degradation of atrazine, in the context of an advanced oxidation process (AOP). The synthesis involves a first step in which polyethylenimine (PEI) capped Cu NPs (PEI_Cu NPs) are prepared, and then deposited onto, separately, MK10 and sand, through a solvent impregnation method. The resulting products are characterized in detail; the copper is found to exist as a mixture of copper (I, II) oxide. The degradation of atrazine follows a second-order kinetic model with constant values of K2 = 1.7957 g mg−1 min−1 for MK10_PEI_Cu NPs and K2 = 0.8133 g mg−1 min−1 for sand_PEI_Cu NPs. The reaction rate is linked to Cu2O and CuO redox-active species within the layers, pores and surface of the host materials. A degradation mechanism is found with application of these composite materials in the presence of H2O2; adsorption occurs in the absence of H2O2. In contrast, the unmodified MK10 and sand exhibit adsorption in both of the above reaction conditions. Finally, the stability of the Cu NPs following degradation is evaluated, and no significant amount of copper leaching is found.

Clay Types Modulate the Toxicity of Low Concentrated Copper Oxide Nanoparticles Toward Springtails in Artificial Test Soils

“…In the present study, the marked CAT inhibition in M30‐NP treatments can be explained by a higher ROS formation overloading the antioxidant system. Reactive oxygen species formation may be caused by the high reactivity of Cu–montmorillonite associations, which are able to break down organic compounds and are known to be more reactive than Cu–kaolin (Khanikar & Bhattacharyya, 2013) or Cu–sand associations (Kalidhasan et al, 2017). For example, Cu–montmorillonite associations can cause a high degradation rate of atrazine through the activation of molecular oxygen and the subsequent hydroxyl radical formation (Hong et al, 2017).…”

“…In the present study, we exposed the standard test organism Folsomia candida to CuO-NPs and CuCl 2 in Organisation for Economic Co-operation and Development (OECD) soils containing either kaolin or montmorillonite as the clay fraction. Both clays are either exemplary for two-or three-layer clay minerals and are widely used, for example kaolin in OECD soil and Montmorillonite K10 in different catalytic (Kalidhasan et al, 2017;Khanikar & Bhattacharyya, 2013) and ecotoxicological studies (Gupta et al, 2016(Gupta et al, , 2017Kansara et al, 2019). We compared the impact of these soils on the toxicity of the Cu substances to the survival, reproduction, growth, molting, and biochemical responses of F. candida.…”

Do organic substances act as a degradable binding matrix in calcium oxalate kidney stones?

“…The second group of chemolytic agents tested here were strong oxidation agents—copper nanoparticles with H 2 O 2 [ 26 ] and Fenton reaction (pH 2–4, Fe 2+ , H 2 O 2 ) [ 27 ]—both of which have been shown highly effective in degrading organic matter in complex matrices. These agents were applied to check their ability to degrade the organic substances and thus weaken or disintegrate the stone.…”

Clay-Supported Metal Oxide Nanoparticles in Catalytic Advanced Oxidation Processes: A Review

“…Mechanistic studies of adsorption and oxidation have revealed the contribution of atrazine adsorption by Cu as an active catalyst via coordination bonding with nitrogen from the atrazine structure, yielding a significant reduction in the chemical oxygen demand of the treated solution. Cu 2 O and CuO identified on the surface are recognized as the redox-active species within the pores, layers, and outside of the montmorillonite surfaces [ 189 ]. In an ionic form, Cu 2+ -immobilized aluminum-pillared montmorillonite (Cu/Al-PILM) showed a capability for use in Fenton and photo-Fenton treatments of RO16 [ 190 ].…”