“…Therefore, the high percentage of Co(II) removal at pH 8 and 10 are due to both precipitation and adsorption process. Similar MB and Co(II) adsorption trends have been reported in other studies 54 , 55 . Figure 7 Effects of pH on ( a ) MB removal by Ze/AC and Ze/L/AC composite, ( b ) Co(II) removal by Ze/AC and Ze/L/AC composites.…”
In this study, we used solvent assisted mechano-synthesis strategies to form multifunctional organic–inorganic nanocomposites capable of removing both organic and inorganic contaminants. A zeolite X (Ze) and activated carbon (AC) composite was synthesized via state-of-the-art mechanical mixing in the presence of few drops of water to form Ze/AC. The second composite (Ze/L/AC) was synthesized in a similar fashion, however this composite had the addition of disodium terephthalate as a linker. Both materials, Ze/AC and Ze/L/AC, were characterized using scanning electron microscope (SEM), energy-dispersive X-ray spectroscopy (EDS), Powdered X-ray diffraction (P-XRD), Fourier-transform infrared spectrometry (FTIR), Accelerated Surface Area and Porosimetry System (ASAP), and thermal gravimetric analysis (TGA). The SEM–EDS displayed the surface structure and composition of each material. The sodium, oxygen and carbon contents increased after linker connected Ze and AC. The P-XRD confirmed the crystallinity of each material as well as the composites, while FTIR indicated the function groups (C=C, O–H) in Ze/L/AC. The contaminant adsorption experiments investigated the effects of pH, temperature, and ionic strength on the adsorption of methylene blue (MB) and Co(II) for each material. In MB adsorption, the first-order reaction rate of Ze/L/AC (0.02 h−1) was double that of Ze/AC (0.01 h−1). The reaction rate of Ze/L/AC (4.8 h−1) was also extraordinarily higher than that of Ze/AC (0.6 h−1) in the adsorption of Co(II). Ze/L/AC composite achieved a maximum adsorption capacity of 44.8 mg/g for MB and 66.6 mg/g for Co(II) ions. The MB adsorption of Ze/AC and Ze/L/AC was best fit in Freundlich model with R2 of 0.96 and 0.97, respectively, which indicated the multilayer adsorption. In the Co(II) adsorption, the data was highly fit in Langmuir model with R2 of 0.94 and 0.92 which indicated the monolayer adsorption. These results indicated both materials exhibited chemisorption. The activation energy of Ze/L/AC in MB adsorption (34.9 kJ mol−1) was higher than that of Ze/L/AC in Co (II) adsorption (26 kJ mol−1).
“…Therefore, the high percentage of Co(II) removal at pH 8 and 10 are due to both precipitation and adsorption process. Similar MB and Co(II) adsorption trends have been reported in other studies 54 , 55 . Figure 7 Effects of pH on ( a ) MB removal by Ze/AC and Ze/L/AC composite, ( b ) Co(II) removal by Ze/AC and Ze/L/AC composites.…”
In this study, we used solvent assisted mechano-synthesis strategies to form multifunctional organic–inorganic nanocomposites capable of removing both organic and inorganic contaminants. A zeolite X (Ze) and activated carbon (AC) composite was synthesized via state-of-the-art mechanical mixing in the presence of few drops of water to form Ze/AC. The second composite (Ze/L/AC) was synthesized in a similar fashion, however this composite had the addition of disodium terephthalate as a linker. Both materials, Ze/AC and Ze/L/AC, were characterized using scanning electron microscope (SEM), energy-dispersive X-ray spectroscopy (EDS), Powdered X-ray diffraction (P-XRD), Fourier-transform infrared spectrometry (FTIR), Accelerated Surface Area and Porosimetry System (ASAP), and thermal gravimetric analysis (TGA). The SEM–EDS displayed the surface structure and composition of each material. The sodium, oxygen and carbon contents increased after linker connected Ze and AC. The P-XRD confirmed the crystallinity of each material as well as the composites, while FTIR indicated the function groups (C=C, O–H) in Ze/L/AC. The contaminant adsorption experiments investigated the effects of pH, temperature, and ionic strength on the adsorption of methylene blue (MB) and Co(II) for each material. In MB adsorption, the first-order reaction rate of Ze/L/AC (0.02 h−1) was double that of Ze/AC (0.01 h−1). The reaction rate of Ze/L/AC (4.8 h−1) was also extraordinarily higher than that of Ze/AC (0.6 h−1) in the adsorption of Co(II). Ze/L/AC composite achieved a maximum adsorption capacity of 44.8 mg/g for MB and 66.6 mg/g for Co(II) ions. The MB adsorption of Ze/AC and Ze/L/AC was best fit in Freundlich model with R2 of 0.96 and 0.97, respectively, which indicated the multilayer adsorption. In the Co(II) adsorption, the data was highly fit in Langmuir model with R2 of 0.94 and 0.92 which indicated the monolayer adsorption. These results indicated both materials exhibited chemisorption. The activation energy of Ze/L/AC in MB adsorption (34.9 kJ mol−1) was higher than that of Ze/L/AC in Co (II) adsorption (26 kJ mol−1).
“…OA4, as for its best output, has been tested out in the range of pH from 3 to 7, above this range precipitates of Co(II) ions formed as Co(OH) 2 69 , and increase in adsorption with pH has been observed. Initial concentration (10 ml), adsorbent dosage (5 mg), stirring (200 rpm) and contact time(1 h) taken as predetermined conditions to tested out pH effect on adsorption behavior of prepared sample.…”
Cobalt, from industrial waste and nuclear laundry, possess health risk to human beings, animals and plants. Number of methods, other than adsorption, have been reported in literature for Co removal from waste water. In this research walnut shell powder after modification has been utilized for Co adsorption. First step of modification involved chemical treatment by four different organic acids for 72 h. Samples were collected at 24, 48 and 72 h. Second step involved thermal treatment of 72 h samples. Unmodified and modified particles have been analyzed by chemical methods and instruments i.e. UV spectrometer, FTIR, cyclic voltammetry (CV) and microscopic imaging. Thermally treated samples have shown augmented Co adsorption. CV analysis showed thermally treated samples with better capacitance. Particles modified by oxalic acid presented better Co adsorption. Oxalic acid treated particles activated for 72 h with thermal treatment provided maximum adsorption capacity 1327 ± 20.6 mg/g against Co(II) at pH 7, stirring 200 rpm, initial concentration 20 ml, adsorbent dosage (5 mg) and contact time 240 min at room temperature.
“…The peak at wavenumber 794 cm -1 corresponds to the presence of Si-O bond (Bamroongwongdee et al, 2019). The vibration at 1,103 cm -1 refers to C-H stretching of lignin in the RH and RH-BC (Gad et al, 2016). Furthermore, the intensity of the water molecule (OH vibration) and carboxylate group (CO vibration) in the RH decreased after heating at 600C to form the RH-BC.…”
Section: Adsorbent Characterizationmentioning
confidence: 99%
“…The adsorption capacity was 7.19 mg/g. Gad et al (2016) also used the RH as an adsorbent of metal ion Co(II) from wastewater, which resulted in a maximum adsorption capacity of 75.70 mg/g, and it followed the Langmuir isotherm model.…”
Indonesian rice husk biochar (RH-BC) was prepared by pyrolysis method at 500°C and characterized using X-ray diffraction, Fourier-transform infrared spectroscopy, surface-area-specific analysis by Brunauer-Emmett-Teller, and scanning electron microscopy. The RH-BC were used as adsorbents for enhancing the adsorption of Congo red compared to pristine rice husk (RH) in aqueous solutions. The results of characterization through surface-area-specific analysis showed the surface area of RH-BC (72.25 m2/g) was ten times higher than RH (7.08 m2/g) owing to high-temperature treatment. The results of the adsorption study showed that the RH and RH-BC followed the pseudo-second-order kinetic model and the Freundlich isotherm equation with maximum adsorption capacities of 85.470 mg/g and 72.993 mg/g for the RH-BC and RH, respectively. The thermodynamic parameters of adsorption indicated spontaneous and endothermic processes. The reusability of the adsorbents (RH and RH-BC) showed that they are potentially suitable for extracting Congo red from aqueous solution up to three adsorption-desorption cycles. Their performance sharply decreases after the fourth and fifth cycles.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
