Microwave-assisted preparation and characterization of organo-attapulgites and comparison for 1-naphthol removal: equilibrium, kinetic, and thermodynamic studies

Yang, Tai; Shi, Chunjie; Li, Guanghui; Wu, Jinhua

doi:10.1080/19443994.2015.1048531

Cited by 2 publications

(1 citation statement)

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“…Based on the literature, the cation exchange capacity (CEC) values of palygorskite mineral aren't so high in comparison with kaolinite or bentonite (Table 2), but palygorskite's specific structure with various functional groups and the high Water Supply Vol 00 No 0, 7 surface area, is capable of adsorption of high quantities of heavy metals from water (Shirvani et al 2006). Moreover, as Tai et al (2016) reported, the sodium modification of palygorskite mineral increased the CEC of the raw palygorskite from 0.278 mmol/g to 0.385 mmol/g, which can increase the calcium adsorption capacity of the Na-Pal sample. To summarizing, 30 g/L of Na-Pal were selected as the optimal and cost-effective dosage for 100 mg Ca 2þ /L removal, which are the initializing parameters for the next batch series tests.…”

Section: Batch Kinetic Experimentsmentioning

confidence: 99%

Ca2+ removal from water by the use of Na-palygorskite for potential water softening

et al. 2021

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Sodium-treated palygorskite (Na-Pal) sample was investigated for the sorption of Ca2+ ions with the aim of treating water hardness. The effective modification of the mineral with Na+ was verified by XRD and FT-IR techniques. Batch kinetic experiments in standard solutions were performed proving that 30 g/L of Na-Pal were highly satisfactory as the Ca2+ removal reached the 85% for 100 mg/L Ca2+ initial concentration, which is very promising for the softening of moderate or hard waters. The Ca2+ removal found to be pH and temperature independent, with high removal rates at room temperature and common pH values of water samples (pH 4–12), rendering these circumstances ideal for the low-cost maintenance of the procedure that took place within the first 5 min. The linear form of Langmuir isotherm model expressed better (R2 = 1) the Ca2+ sorption, which means that takes place at specific homogeneous sites of Na-Pal. Thermodynamic analysis proved the non-spontaneous (positive ΔG0), physical, and exothermic nature (ΔH0 = −10.8197 kJ/mol) of the reaction, while the kinetic models proved the chemisorption of Ca2+ by Na-Pal.

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Section: Batch Kinetic Experimentsmentioning

confidence: 99%