Abstract:Applicability of the new material pyrolyzed Delonix regia pod carbon for the removal of excess fluoride ions from the water that harm the human and the environment was studied. The adsorbent was characterized both physically and chemically. Surface chemistry characterization was done with pH-drift method. Batch adsorption studies were carried out for the effect of pH, dosage, contact time, initial fluoride concentration, temperature and interfering co-ions. The physicochemical properties and textural character… Show more
“…Because of the strong columbic force that exists between the dye molecules and the positively charged surface of DRB-SO, their adsorptions are highly effective in acidic environments. The adsorption of MO and MR dyes was poor in alkaline media; this might be because the negatively charged surface of DRB-SO and the dye molecules resisted each other 45 – 47 . Figure 7 ( a ) pH study for adsorption of methyl orange (100 mg/L) and methyl red (100 mg/L) on Delonix regia biochar-sulfur (DRB-SO), ( b ) pH zero point charge (pH ZPC ) for D. regia biochar-sulfur oxide (pH ZPC of DRB-SO).…”
In this study, Delonix regia seed pods (DRSPs) as a locally available material were refluxed in 90% H2SO4 to yield a novel D. regia seed pods biochar-sulfur oxide (DRB-SO). FTIR, BET, BJH, SEM, EDX, XRD, DSC and TGA were applied to investigate the characterizations of the prepared DRB-SO. Various adsorption parameters like pH effect, dye concentration effect, adsorbent dose, reaction time isotherm and kinetic study were carried out to explain the process of adsorption of methyl orange (MO) and methyl red (MR) onto DRB-SO. Langmuir's adsorption model perfectly explained the adsorption process onto the surface of DRB-SO as a monolayer. The maximum adsorption efficiency of DRB-SO was (98%) and (99.6%) for MO and MR respectively which attained after 150 min with an adsorbent dose of 0.75 g/L. The pseudo-second-order kinetic model best explained the process of adsorption of MO and MR dyes by DRB-SO. The highest observed adsorption amount was as high as 144.9 mg/g for MO dye and 285.7 mg/g for MR dye, comparable with other reported materials based on activated carbon materials. All of the outcomes signposted a prodigious perspective of the fabricated biochar composite material in wastewater treatment. Using the regenerating DRB-SO through an acid–base regeneration process, six cycles of adsorption/desorption were examined. Over the course of the cycles, there was a minor decrease in the adsorption and desorption processes. Also, it was revealed what the most plausible mechanism was for DRB-SO to absorb the ions of the MO and MR dyes.
“…Because of the strong columbic force that exists between the dye molecules and the positively charged surface of DRB-SO, their adsorptions are highly effective in acidic environments. The adsorption of MO and MR dyes was poor in alkaline media; this might be because the negatively charged surface of DRB-SO and the dye molecules resisted each other 45 – 47 . Figure 7 ( a ) pH study for adsorption of methyl orange (100 mg/L) and methyl red (100 mg/L) on Delonix regia biochar-sulfur (DRB-SO), ( b ) pH zero point charge (pH ZPC ) for D. regia biochar-sulfur oxide (pH ZPC of DRB-SO).…”
In this study, Delonix regia seed pods (DRSPs) as a locally available material were refluxed in 90% H2SO4 to yield a novel D. regia seed pods biochar-sulfur oxide (DRB-SO). FTIR, BET, BJH, SEM, EDX, XRD, DSC and TGA were applied to investigate the characterizations of the prepared DRB-SO. Various adsorption parameters like pH effect, dye concentration effect, adsorbent dose, reaction time isotherm and kinetic study were carried out to explain the process of adsorption of methyl orange (MO) and methyl red (MR) onto DRB-SO. Langmuir's adsorption model perfectly explained the adsorption process onto the surface of DRB-SO as a monolayer. The maximum adsorption efficiency of DRB-SO was (98%) and (99.6%) for MO and MR respectively which attained after 150 min with an adsorbent dose of 0.75 g/L. The pseudo-second-order kinetic model best explained the process of adsorption of MO and MR dyes by DRB-SO. The highest observed adsorption amount was as high as 144.9 mg/g for MO dye and 285.7 mg/g for MR dye, comparable with other reported materials based on activated carbon materials. All of the outcomes signposted a prodigious perspective of the fabricated biochar composite material in wastewater treatment. Using the regenerating DRB-SO through an acid–base regeneration process, six cycles of adsorption/desorption were examined. Over the course of the cycles, there was a minor decrease in the adsorption and desorption processes. Also, it was revealed what the most plausible mechanism was for DRB-SO to absorb the ions of the MO and MR dyes.
“…Generally, The sorption of cationic and anionic species was carried out by agitating 0.02 g of some prepared activated carbons (samples no. 7,10,11,12,13,17,19,23,25,28,31,35, and 37, with 5 mL of cations [ 137 Cs, 85 Sr, La(III), Eu(III), Co(II), U(VI)] and anions [ 75 Se, Cr(VI) and Mo(VI)] solutions of concentration 20 mg/L in the sealed bottle (50 mL) at 25 °C for 24 h. Generally, the pH was set at about pH 3 in the case of the anion species and at a pH 5 in the case of cation species. Aqueous solutions cationic and anionic species were prepared by dissolving known amounts of corresponding salts of these species in DDW, which were labeled with [ 137 Cs, 85 Sr and 75 Se in the case of Cs(I), Sr(II) and Se(IV)].…”
Delonix regia pods have been used to produce high-efficiency and low-cost activated carbons using different activation methods. The ability of these prepared sorbents to remove cations [ 137 Cs, 85 Sr, La(III), Eu(III), Co(II), U(VI)] and anions [ 75 Se, Cr(VI), Mo(VI)] was evaluated in mono-component systems and the sorbents number 11, 13, 25, and 35 showed high removal efficiency. These sorbents also show the high ability to remove organic pollutants such as methylene blue and phenol. This study highlighted the extensive applicability of these low-cost sorbents in the sequestration of anionic and cationic radionuclides from real radioactive wastewaters and different environmental samples.
BACKGROUND: Composites of defluoridation adsorbents based on rare earths have attracted increasing interest recently, but most of them were amorphous. The main reason for this situation is that morphology control has not been paid enough attention, because the related preparation methods are relatively sparse. Consequently, novel preparation methods are urgently needed.
RESULTS:In this study, a novel La-Zr-Ce tri-metal adsorbent with regular morphology was facilely synthesized. There were two morphological shapes in the composite. Nanoprisms of La 2 (C 2 O 4 ) 3 were decorated with mesoporous nanospheres of Fe 3 O 4 @m(ZrO 2 -CeO 2 ). The samples were investigated by energy-dispersive spectroscopy (EDS), scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray diffraction (XRD), vibrating sample magnetometer (VSM) and X-ray photoelectron spectroscopy (XPS). Several affecting factors such as initial fluoride concentration, contact time, coexisting anions and pH were studied in detail. The balance data were analyzed by Langmuir, Freundlich and Langmuir-Freundlich isotherm models. The nanocomposite had a maximum sorption capacity of 117.3 mg g −1 toward fluoride, which is among the highest ever reported for fluoride adsorbents. Furthermore, it had a wide applicable pH range of 2-10 and high anti-interference ability. The different functions of La 2 (C 2 O 4 ) 3 nanoprisms and Fe 3 O 4 @m(ZrO 2 -CeO 2 ) nanospheres in the composite have been elucidated. These two components were found to synergistically improve F − adsorption performance via their individual merits. CONCLUSION: The adsorbent had high potential to treat F − contaminants in real application, and the method reported here is considered to be helpful for developing more highly effective adsorbents.
Adsorption isothermsAdsorption isotherms of the adsorbents were investigated by Langmuir (Equ. S2 in File S1), Freundlich (Equ. S3 in File S1) and J Chem Technol Biotechnol 2019; 94: 3650-3660 /jctb CONCLUSIONS A novel La-Zr-Ce tri-metal adsorbent with regular morphology was successfully synthesized by step-by-step precipitation methods and showed excellent fluoride removal performance. There J Chem Technol Biotechnol 2019; 94: 3650-3660
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