Sorption of atrazine, propazine, deethylatrazine, deisopropylatrazine and hydroxyatrazine onto organovermiculite

Abstract

hexadeciltrimetil-amônio (HDTMA-VT) no espaço interlamelar. A VTK bruta teve interação desprezível com AT, PROP e DEA, interação moderada com DIA e forte interação com HAT. No caso do material HDTMA-VT as porcentagens de remoção em meio aquoso (concentrações iniciais entre 0,05 a 1,00 mg L -1 ) foram: 56 -63% para AT, 43 -45% para DEA, 30 -24% para DIA, 12 -19% para HAT e 77 -78% para PROP. As taxas de sorção de AT, DEA e PROP em HDTMA-VT foram significativamente aumentadas com relação a VTK. Força iônica e pH tiveram pouca influência na sorção. A dessorção dos compostos previamente sorvidos sobre os minerais HDTMA-VT variou de 20 a 30% após um tempo de contacto de 24 h.The interaction of atrazine (AT), propazine (PROP), deethylatrazine (DEA), deisopropylatrazine (DIA) and hydroxyatrazine (HAT) was studied with the clay mineral vermiculite saturated with K + (VTK), and with the mineral modified by insertion of hexadecyltrimethyl-ammonium (HDTMA-VT) in the interlayer of VTK. The crude VTK exhibited negligible interaction with AT, PROP and DEA, moderate interaction with DIA and strong interaction with HAT. For the HDTMA-VT materials, removal percentages from aqueous medium for initial concentrations between 0.05 and 1.00 mg L -1 were 56 to 63% for AT, 43 to 45% for DEA, 12 to 19% for HAT and 77 to 78% for PROP. Sorption of AT, DEA and PROP onto HDTMA-VT was significantly enhanced in comparison to VTK. Ionic strength and pH had no significant influence on the sorption process. Desorption of all compounds from HDTMA-VT after 24 h of contact time was between 20 and 30% of the amount initially adsorbed.

Organic xenobiotics removal in constructed wetlands, with emphasis on the importance of the support matrix

“…Some of the most popular types of clay minerals (kaolinite, illite, montmorillonite, vermiculite, sepiolite, bentonite) have been tested to remove by adsorption a variety of organic pollutants such as dyes [182][183][184][185][186][187][188][189][190][191], pesticides [74,[192][193][194][195][196], PAHs [124,189,197], pharmaceuticals [74,75,157,[175][176][177], phenolic compounds [125,174,198] and other aromatics [124,174,189,198]. In the vast majority of these studies the organic substances are removed most commonly from pure water solutions in batch adsorption assays.…”

Matéria orgânica em quatro tipos de solos brasileiros: composição química e sorção de atrazina

“…18,19 Em solos sob vegetação nativa, a matéria orgânica associada a solos cauliníticos tende a apresentar maior proporção de estruturas tipo carboidratos, enquanto que a matéria orgânica de solos esmectíticos é mais rica em grupamentos aromáticos e carboxílicos. 20,21 A contribuição da fração argila, embora menos expressiva que a da matéria orgânica, para a sorção da atrazina foi estudada por alguns autores 17,22 e considerada relevante apenas em solos cujos teores de matéria orgânica são baixos. Quanto ao tipo de mineral, argilominerais do tipo 2:1 apresentam maior contribuição para a sorção de atrazina comparativamente aos minerais 1:1.…”

Sorption and Desorption of Atrazine on Natural Bentonite and Organically Modified Bentonite

“…Such a behavior reveals that the surfactant modified bentonite has potential application in controlrelease formulation of atrazine (Trigo et al, 2010). Moreover, another potential application is the improvement of stationary phases for chromatographic columns that could be eluted utilizing water as mobile phase (Abate and Masini 2005;Dutta and Singh 2015). The hysteresis of atrazine adsorption-desorption isotherms on natural bentonite and modified bentonite clays are shown in Figure 4.…”

“…These values of N indicate a constant relative affinity of the solute molecules by the adsorbent, C-type isotherm (Table 3). This implies that non-specific interactions occur amongst solute and adsorbent (Abate and Masini 2005). HDTMA-bentonite contain paraffin-like layer of organic phase in the interlayer of the clay lattice, which acts as the partition medium for the sorption of atrazine.…”