Paraquat adsorption onto clays and organoclays from aqueous solution

Seki, Yoldaş; Yurdakoç, Kadir

doi:10.1016/j.jcis.2004.10.072

Cited by 95 publications

(62 citation statements)

References 25 publications

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“…Organoclays are synthesized by exchanging the naturally occurring inorganic cations with organic cations. By exchanging organic cations on the surface of clay minerals, a material with radically different physical and chemical properties is produced (Seki et al 2005;Jaynes et al 1991). Modification of clay minerals by ion exchange with organic cations has been shown to have a significant impact on their sorptivity (Richard et al 2001;Wiles et al 2005;Klumpp et al 2004).…”

mentioning

confidence: 99%

Sorption of 1,1,1-trichloro-2,2-bis(p-chlorophenyl) ethane (DDT) by clays and organoclays

Rong-ling

Zhang

Xiaozhi

et al. 2008

Environ Geochem Health

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This study focused on the sorption isotherms of 1,1,1-trichloro-2,2-bis(p-chlorophenyl) ethane (p,p'-DDT) and 1,1-dichloro-2,2-bis(p-chlorophenyl) ethylene (p,p'-DDE) on different original clays (i.e., zeolite, montmorillonite and attapulgite) and organoclay complexes. Sorption of organic pollutants was determined using gas chromatographic (GC) techniques to investigate the sorption behavior, and characterize the effect of, different organic cations. The original clays only sorbed low amounts of p,p'-DDT and p,p'-DDE, and the sorptive curves can be classified as L-shaped. Organoclays exhibited higher amounts of p,p'-DDT and p,p'-DDE sorption. The p,p'-DDT and p,p'-DDE sorption increased with increasing total organic carbon (OC) content of the organoclays. For hexadecyltrimethylammonium (HDTMA)-modified organoclays, the dominant adsorptive medium showed the partitioning sorption of hydrophobic-hydrophobic interaction, indicating no competitive sorption. The sorptive curves can be classified as C-shaped of constant partition (CP). However, benzyltrimethylammonium (BTMA)-modified organoclays exhibited competitive sorption. The sorption isotherm curves can be classified as S-shaped. The sorptive capacity of the HDTMA-modified organoclays for p,p'-DDT were higher than those for p,p'-DDE, but the BTMA-modified organoclays showed a reverse trend. This can be attributed to the different structures and shapes of organic cations, giving different sorptive mechanisms. The p,p'-DDT and p,p'-DDE sorption onto HDTMA-modified organoclays were caused by chemical interaction, with the BTMA modified organoclays occuring due to physical sorption.

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mentioning

confidence: 99%

Sorption of 1,1,1-trichloro-2,2-bis(p-chlorophenyl) ethane (DDT) by clays and organoclays

Rong-ling

Zhang

Xiaozhi

et al. 2008

Environ Geochem Health

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“…The adsorption ability was related to the exchange ability of ammonium cation with the clay interlayer cation. In addition, the paraquat interaction to the organoclays depended on the thickness of the organic layer and size of paraquat molecules (Seki and Yurdakoc¸, 2005). Keawkumay et al (2012) reported an intercalation of Mt by octadecylammonium chloride (ODA).…”

Section: Introductionmentioning

confidence: 99%

“…The modification increased the interlayer spacing (1.38 nm of Mt to 1.62 nm of ODA-Mt), and the obtained material was suitable as a filler of rubber nanocomposite. Such sample may work as an adsorbent for paraquat but the long carbon chain could lower the adsorption capacity (Seki and Yurdakoc¸, 2005). Therefore, tetradecylammonium chloride (TDA) which has a shorter carbon chain was selected instead for the Mt modification in this work.…”

Section: Introductionmentioning

confidence: 99%

Adsorption of paraquat and pirimiphos-methyl by montmorillonite modified with tetradecylammonium chloride and intragallery templating method

Keawkumay

Rakmae

Rongchapo

et al. 2016

Adsorption Science & Technology

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Adsorption of paraquat and pirimiphos-methyl in water was performed on four adsorbents including montmorillonite (Mt), organoclay (TDA-Mt) from intercalation of Mt with tetradecylammonium chloride, and mesoporous Mt from intragallery templating method (with and without Ti addition). The adsorbents were characterized by X-ray diffraction, N 2 adsorptiondesorption, and transmission electron microscopy. Paraquat adsorption isotherms followed Langmuir model and the adsorption capacity was as follows: TDA-Mt > Mt > mesoporous TiMt > mesoporous Mt. The adsorption mechanism on TDA-Mt and Mt might be via ion exchange. The adsorption on mesoporous samples was on the external surface with negative charge. The presence of Ti enhanced the adsorption capacity. Pirimiphos-methyl adsorbed on negative charge of the external surface of Mt samples. The adsorbed amount increased with the initial concentration due to a strong intermolecular interaction.

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“…Studies on the adsorption of those pesticides in soil, sediments, clays and organ-clays have been conducted previously on high performance liquid chromatographic [1,4], radioactivity [5,6], X-ray diffraction [7,8], fluorescence and electron-spin resonance spectroscopy [9], and infrared spectroscopy [10].…”

Section: Introductionmentioning

confidence: 99%

The Employ of Multiple Voltammetric Pulses for the Study of the Adsorption of Bipyridilium Pesticides in River Sediment

2006

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The multiple square-wave voltammetry (MSWV) allied to gold microelectrode (Au-ME) was used to establish an electroanalytical procedure for the determination of the paraquat and diquat pesticides in river sediment samples. For both pesticides, two reduction peaks, at around À 0.70 V (peak 1) and around À 1.00 V vs. Ag/AgCl 3.00 mol L À1(peak 2), with profile of the totally reversible redox process, were observed. The experimental and voltammetric conditions showed that the best conditions to reduce paraquat and diquat were a pH of 6.0, a frequency of 250 s À1 , a scan increment 2 mV, a square-wave amplitude of 50 mV and pulse number of 8 pulses of potential in each step of staircase of potential. Under such conditions, the detection limit of 0.044 mg L À1 (0.044 ppb) and 0.360 mg L À1(0.360 ppb) for peak 1 and peak 2 of paraquat and 0.159 mg L À1 (0.159 ppb) and 0.533 mg L À1 (0.533 ppb) for peak 1 and peak 2 of diquat, respectively, were obtained. These results are an order of magnitude of about two less than those obtained and published in the literature. Also, the electroanalytical procedure proposed was applied for the determination of adsorption isotherms of pesticides on river sediments samples collected from Mogi-GuaÅu River in Sao Paulo State, Brazil. The experimental data were fitted using the Langmuir and Freundlich isotherms models; and the results indicated low intensities of adsorption process of the pesticides in the samples employed with distribution coefficients (K d ) lower 5.0, and paraquat showed slightly higher affinity than diquat in the sediments. The increase in organic matter and organic carbon leads to an increase in the K d values, and consequently an increase in the organic matter constant (K OM ) organic carbon constant (K OC ) values. All results demonstrated that isotherms "L" type in the Giles classification were obtained, indicating that sediments have a medium affinity for the pesticides, and no strong competition from the solvent used (in this case Na 2 SO 4 ) for adsorption sites occurs.

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Paraquat adsorption onto clays and organoclays from aqueous solution

Cited by 95 publications

References 25 publications

Sorption of 1,1,1-trichloro-2,2-bis(p-chlorophenyl) ethane (DDT) by clays and organoclays

Sorption of 1,1,1-trichloro-2,2-bis(p-chlorophenyl) ethane (DDT) by clays and organoclays

Adsorption of paraquat and pirimiphos-methyl by montmorillonite modified with tetradecylammonium chloride and intragallery templating method

The Employ of Multiple Voltammetric Pulses for the Study of the Adsorption of Bipyridilium Pesticides in River Sediment

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