The effects of pH and salinity on kinetics of paraquat sorption onto activated clay

Tsai, Wen‐Tien; Lai, Chih‐Wei; Hsien, Kuo-Jong

doi:10.1016/s0927-7757(03)00258-9

Cited by 51 publications

(59 citation statements)

References 19 publications

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“…After 2 h of shaking, for both clay loam and clay soils additional adsorption of paraquat became very slow and reached a constant after achieving equilibrium between the soil matrix and solution. Similar adsorption kinetics and adsorption patterns of paraquat have been reported by Tsai et al (2003) and Weber and Scott (1966). Tsai et al (2003) reported that adsorptive equilibrium for paraquat was attained within 60-120 min in clay soil.…”

Section: Resultssupporting

confidence: 82%

“…Similar adsorption kinetics and adsorption patterns of paraquat have been reported by Tsai et al (2003) and Weber and Scott (1966). Tsai et al (2003) reported that adsorptive equilibrium for paraquat was attained within 60-120 min in clay soil. Similarly, Cheah et al (1997) reported that paraquat adsorptive equilibrium was attained within 4 h in sandy loam.…”

Section: Resultssupporting

confidence: 82%

“…The surface of activated clay exhibits negative charges under these experimental conditions (i.e., pH > 2.0), mainly due to the variable charges from the pHdependent surface hydroxyl sites. These negative charges increase with increasing pH, consistent with the results showing that adsorbed amounts of pesticide increase with increasing pH values (Gevao et al 2000;Tsai et al 2003).…”

Section: Effect Of Phsupporting

confidence: 90%

“…Results showed that pH of the soil affected the adsorption of paraquat on clay loam and clay soils. Adsorption of paraquat was found to be higher at high pH for both soil types, supporting the results of Tsai et al (2003). At pH 11, the amounts of 14 C-labeled paraquat adsorbed onto the clay loam and clay soil samples were 4.08 and 4.05 μg g −1 , respectively, whereas at pH 2, the amounts adsorbed were 3.72 and 3.57 μg g −1 for both types of soil, respectively.…”

Section: Effect Of Phsupporting

confidence: 84%

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Adsorption study of 14C-paraquat in two Malaysian agricultural soils

Muhamad

Ismail

Sameni

et al. 2010

Environ Monit Assess

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The adsorption equilibrium time and effects of pH and concentration of (14)C-labeled paraquat (1,1(')-dimethyl-4,4(')-bipyridylium dichloride) in two types of Malaysian soil were investigated. The soils used in the study were clay loam and clay soils from rice fields. Equilibrium studies of paraquat in a soil and pesticide solution were conducted. Adsorption equilibrium time was achieved within 2 h for both soil types. The amount of (14)C-labeled paraquat adsorbed onto glass surfaces increased with increasing shaking time and remained constant after 10 h. It was found that paraquat adsorbed by the two soils was very similar: 51.73 (clay loam) and 51.59 μ g g(-1) (clay) at 1 μ g/ml. The adsorption of paraquat onto both types of soil was higher at high pH, and adsorption decreased with decreasing pH. At pH 11, the amounts of (14)C-labeled paraquat adsorbed onto the clay loam and clay soil samples were 4.08 and 4.05 μ g g(-1), respectively, whereas at pH 2, the amounts adsorbed were 3.72 and 3.57 μ g g(-1), respectively. Results also suggested that paraquat sorption by soil is concentration dependent.

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Section: Resultssupporting

confidence: 82%

Section: Resultssupporting

confidence: 82%

Section: Effect Of Phsupporting

confidence: 90%

Section: Effect Of Phsupporting

confidence: 84%

See 2 more Smart Citations

Adsorption study of 14C-paraquat in two Malaysian agricultural soils

Muhamad

Ismail

Sameni

et al. 2010

Environ Monit Assess

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“…These observations indicated that as the pH increased, the adsorbed amount of cationic paraquat increased in response to the increasing number of negatively charged sites that are available due to the loss of H ? from the surface (Tsai et al 2003b). As seen in Table 1 and Fig.…”

Section: Effect Of Initial Phmentioning

confidence: 76%

Adsorption kinetics of herbicide paraquat in aqueous solution onto a low-cost adsorbent, swine-manure-derived biochar

Tsai

Chen

2013

Int. J. Environ. Sci. Technol.

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Biochars have received increasing attention in recent years because of their significant properties such as carbon sequestration, soil fertility, and contaminant immobilization. In this work, the adsorptive removal of paraquat (1,1 0 -dimethyl-4,4 0 -dipyridinium chloride, one of the most widely used herbicides) from aqueous solution onto the swine-manure-derived biochar has been studied at 25°C in a batch adsorption system. The adsorption rate has been investigated under the controlled process parameters including initial pH (i.e., 4.5, 6.0, 7.5, and 9.0), paraquat concentration (i.e., 0.5, 1.0, 2.0, 4.0, and 6.0 mg/L), and biochar dosage (i.e., 0.10, 0.15, 0.20, 0.25, and 0.30 g/L). Based on the adsorption affinity between cationic paraquat and carbon-like adsorbent, a pseudo-second order model has been developed using experimental data to predict the adsorption kinetic constant and equilibrium adsorption capacity. The results showed that the adsorption process could be satisfactorily described with the reaction model and were reasonably explained by assuming an adsorption mechanism in the ion exchange process. Overall, the results from this study demonstrated that the biomassderived char can be used as a low-cost adsorbent for the removal of environmental cationic organic pollutants from the water environment.

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Comparison Study of Paraquat Herbicide Adsorption by Xerogels: Application of Experimental Design

Shamsodin

Fazli

Nasiri

2018

Env Prog and Sustain Energy

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This study dealt with the Paraquat dichloride herbicide (PQT) adsorption on xerogels. The xerogels were synthesized with tetra methoxy orthosilicate (TMOS) and tetra ethoxy orthosilicate (TEOS) as a precursor. Whereas xerogels have free silanol groups on their surface and PQT has a positive charge as an ion, xerogels have shown a high affinity for the PQT adsorption in aqueous solution. Scanning Electron Microscopy, Fourier Transform‐IR, and BET analysis were characterized xerogels. The effect of four process factors such as PQT dosage, pH, a dose of adsorbent, and time was evaluated by the Box‐Behnken design. Between four parameters, pH was more effective. The second order equation (quadratic model) was also used for the analysis of the experimental data. Additionally, the optimum points for parameters were determined by desirability function in the Experimental Design. Removal Percentages of PQT at the optimum process parameters were found to be 98.05 and 92.83%, for TMOS and TEOS xerogels, respectively. In addition, the isotherm study showed that the Freundlich isotherm indicated better harmonic between experimental and theoretical results. Finally, in the kinetic study, Pseudo‐second order model had a better correlation than Pseudo‐first order model. © 2018 American Institute of Chemical Engineers Environ Prog, 38: S128–S138, 2019

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The effects of pH and salinity on kinetics of paraquat sorption onto activated clay

Cited by 51 publications

References 19 publications

Adsorption study of 14C-paraquat in two Malaysian agricultural soils

Adsorption study of 14C-paraquat in two Malaysian agricultural soils

Adsorption kinetics of herbicide paraquat in aqueous solution onto a low-cost adsorbent, swine-manure-derived biochar

Comparison Study of Paraquat Herbicide Adsorption by Xerogels: Application of Experimental Design

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