Adsorption Kinetic Behavior Research Articles

Jackfruit waste derived oxygen-self-doped porous carbon for aqueous Zn-ion supercapacitors

To fully harness the benefits of high energy density, strategic fabrication of hierarchical porous carbon (PC) materials is essential and highly impactful. In this study, oxygen-self-doped PC materials are synthesized from jackfruit waste (JK) through pyrolysis combined with chemical activation. The resulting material (JKPC-4) features abundant interfacial active sites and a short ions/electrons transfer distance, enhancing the ion adsorption capacity and kinetic behavior of the cathode. Additionally, the oxygen-rich functional groups contribute to increased pseudocapacitance and enhance the wettability and conductivity of the material. Consequently, the assembled JKPC-4//JKPC-4 symmetric supercapacitor in 2M Na2SO4 electrolyte exhibits a high energy density of 36.06 Wh kg−1 at 647.94 W kg−1. Furthermore, the JKPC-4//Zn device demonstrates a notable capacity of 225 mAh g−1 at 0.1 A g−1, exceptional rate capability (93 mAh g−1 at 10 A g−1), high energy density (154 Wh kg−1), and impressive cycle stability, retaining 97 % of its capacity after 10,000 cycles at 10 A g−1. The electrochemical process is studied using ex-situ characterization. Mechanistic studies have shown that the outstanding energy storage capability and charge-transfer processes of JKPC-4 stem from the synergistic interplay between oxygen heteroatoms and suitable pore structure.

Hydrogen and Carbon Dioxide Kinetic Adsorption and Diffusion Behavior into Organic-Rich Shale: Implications of Mineralogy and Organic Content

Hydrogen and Carbon Dioxide Kinetic Adsorption and Diffusion Behavior into Organic-Rich Shale: Implications of Mineralogy and Organic Content

Kinetics of Cd adsorption by biochar, activated carbon, and zeolite in some calcareous soils

AbstractDifferent methods have developed to reduce the risks of potentially toxic elements in contaminated soils. Among them, adsorption is one of the most important and effective strategies. In this research, kinetics of Cd adsorption by biochar, activated carbon, and zeolite in some calcareous soils were investigated. A factorial experiment was conducted based on a completely randomized design with three replications. The factors included three types of adsorbents (sunflower's biochar, activated carbon, and zeolite), four levels of Cd (0, 20, 50, and 100 mg/L as Cd (NO3)2), and three soil samples, differing in their cation exchange capacity, soil organic matter, and calcium carbonate equivalent. Batch experiments were carried out to evaluate Cd adsorption isotherms and kinetic models. Furthermore, the effect of adsorbent dosage, contact time, and initial pH on the adsorption efficiency was examined. Optimizing studies revealed that the best pH for Cd adsorption was 5, while the optimal equilibrium time was achieved at 24 h. The results showed that the Freundlich model fitted to the experimental data slightly better than the Langmuir model. Moreover, the pseudo‐second‐order kinetic model better described the kinetic behavior of Cd adsorption for the investigated adsorbents. The maximum Cd removal efficiency (99%) belonged to soil No. 2 with biochar. Lastly, it was concluded that sunflower biochar, a cheap and cost‐effective adsorbent, had high efficiency in Cd adsorption in calcareous soils.

Adsorbent prepared from bentonite to remove diethyl phthalate in aqueous solution

In this study, zeolite synthesized based on bentonite via the alkali fusion-hydrothermal method, and the effects of different synthesis parameters on the crystallinity and silicon-aluminum ratio of zeolite were investigated. The zeolite particles were modified by cationic surfactant and magnetized to prepare a MCTAB-BZ composite, which was then applied to the adsorption of diethyl phthalate (DEP) from aqueous solution. The effects of operating factors, including pH value, adsorption dosage, temperature, and adsorption time on the kinetic and isotherm adsorption behavior were studied. Highly crystalline ANA-zeolite can be prepared with the alkali content of 1:1, the aging time of 20 h, the aging water content of 1:15, and the crystallization time of 24 h. The results of the adsorption experiment show that the novel adsorbent-MCTAB-BZ composite shows the best adsorption capacity when the adsorption dosage is 6.25 g/L, temperature is 30 °C and adsorption time is 180 min at the original pH value of the aqueous solution. The adsorption results are presented well by the pseudo-second-order kinetic model and the Freundlich isotherm model.

Mixed-Mode Adsorption of l-Tryptophan on D301 Resin through Hydrophobic Interaction/Ion Exchange/Ion Exclusion: Equilibrium and Kinetics Study.

The adsorption of l-tryptophan (l-Trp) was studied based on the hydrophobic interaction/ion exchange/ion exclusion mixed-mode adsorption resin D301. Firstly, the interaction mode between l-Trp and resin was analyzed by studying the influence of pH variation on the adsorption capability and the dissociation state of l-Trp. Secondly, the adsorption mechanism was illuminated by studying the adsorption equilibrium and kinetic behaviors. The adsorption equilibrium and a kinetics model were constructed. The augmentation of pH gradually elicited an enhancement in the adsorption capacity of l-Trp. l-Trp existing in varied dissociation states could be adsorbed by the resin, and the interaction mode relied upon the pH of the solution. An integrated adsorption equilibrium model with the coadsorption of different dissociation states of l-Trp was developed and could predict the adsorption isotherms at various pH levels satisfactorily. Both external mass transfer and intra-particle diffusion collectively imposed constraints on the mass transfer process of l-Trp onto the resin. An improved liquid film linear driving force model (ILM) was constructed, and the model provided a satisfactory fit for the adsorption kinetics curves of l-Trp at various pH levels. l-Trp molecules had a high mass transfer rate at a relatively low solution pH.

Construction of nanocomposite hydrogel by TiO2-carbon quantum dots encapsulated in alginate with a highly efficient adsorption and photodegradation of dye pollutants

This presentation introduces an integrated photocatalyst/adsorbent system, achieved through immobilization and encapsulation of the TiO2 doped with CQDs (carbon quantum dots) nanocomposite within the calcium alginate (CaAlg) matrix. The nanoparticles and nanocomposites were analyzed using various techniques, including FE-SEM, EDX, TEM, XRD, PL, FT-IR, BET, and UV–vis DRS, to determine their structure and properties. The TiO2/CQDs/Alg nanocomposite hydrogel considerably influenced the adsorption and photocatalytic degradation of methylene blue (MB) as a dye pollutant. The adsorption studies were conducted to assess parameters such as adsorption capacity, kinetic behavior, and adsorption isotherms. The outcomes revealed a high adsorption capacity (44.13 mg/g at 90 min) and indicated that the pseudo-second-order kinetic model was highly suitable for describing the adsorption behavior of MB. Moreover, the Freundlich isotherm exhibited better fitting capabilities compared to the Langmuir isotherm. CQDs not only facilitated the transfer of photoelectrons from the TiO2 surface, preventing recombination of electron-hole pairs but also enhanced visible light absorption by the upconversion photoluminescence. The TiO2/CQDs/Alg displayed excellent photodegradation performance (97 %) of MB compared with TiO2 and TiO2/CQDs under visible light due to the abundance of active sites for MB adsorption and photocatalytic reactions. The TiO2/CQDs/Alg hydrogel exhibited excellent reusability in degrading MB for up to five consecutive cycles and showed significant swelling behavior across a broad pH range, reflecting the hydrogel's exceptional stability. The use of charge carrier scavengers indicated that O2˙−radicals were the primary surface species involved in the photodegradation of MB.

Poly (ethylene imine)-mediated dihydroxy-functionalized resin with enhanced adsorption capacity for the extraction of boron from salt lake brine

Boron selective resin is a crucial material used for extracting boron from salt lake brine, but the adsorption capacity of resin remains to be improved. In this work, a boron selective resin with high adsorption capacity was created by modifying branched poly (ethylene imine) (PEI) on chloromethyl polystyrene resin, followed by reacting with D-(+)-gluconic acid δ-lactone. The influence of surface hydroxyl content on adsorption capacity of the resin was investigated by varying molecular weights of PEI during modification. The adsorption mechanism of boric acid was explored by changing pH and composition of solution, and by analyzing the adsorption thermodynamic and kinetic behaviors. Furthermore, the selectivity of resin was assessed by the effects of coexisting ions on the adsorption rate of boric acid. The results show that PEI modification effectively increases the content of hydroxyl on the surface of the resin so as to enhance the adsorption capacity of the resin towards boric acid up to 39.4 mg/g. Also, the adsorption rate can still reach up to 75 % even in the presence of 400 times coexisting ion, showing a good selectivity. Furthermore, the adsorption of boric acid is primarily driven by boronate affinity rather than an anion exchange in alkaline solution. Finally, the dynamic extraction of boric acid was carried out, and gives an enrichment factor of up to 39.6 on fixed bed, demonstrating a potential of the resin in the field of boron extraction.

Investigation of Adsorption Optimization, Kinetic and Isotherm Behaviors of 60Co and 152+154Eu Radioisotopes from Nuclear Radioactive Wastewater onto a Novel Co0.5Ni0.5O–Co2Mo3O8–CuO–ZnO Perovskite Metal Oxides Nanosorbent

Herein in this study, a new nanosorbent consisted of perovskite cobalt–nickel oxide Co0.5Ni0.5O and perovskite cobalt–molybdenum oxide Co2Mo3O8, copper oxide CuO, and zinc oxide ZnO, has been synthesized. The structural and morphological properties of the nanosorbent were established by using FT-IR, PXRD, TGA, HR-TEM, SEM, and EDX. The nanosorbent was implemented to adsorb 60Co and 152+154Eu radioactive isotopes under diverse conditions using different pH values, contact times, radioactive nuclides concentrations, and temperatures. The highest adsorption removal for both radionuclides was obtained at pH 6.0 as 83.65 and 122.50 mg/g for 60Co(II), and 152+154Eu(III), respectively. The adsorption models for 60Co(II) were fitted with Temkin only, on the other hand, the adsorption of 152+154Eu(III) was fitted with four adsorption models. The kinetics for 60Co(II) were fitted with the Pseudo first order (PFO), Pseudo second order (PSO), and Intraparticle models on the other hand 152+154Eu(III) were found to agree with the Pseudo first order (PFO) and intraparticle models.

Biosorption of Cadmium by Living and Non‐living Cells of Pseudomonas aeruginosa DR7

ABSTRACTThe global concern over health issues related to heavy metal pollution has driven the adoption of various treatment technologies. The investigation into optimal conditions for cadmium biosorption and bioaccumulation was conducted using a resilient bacterial strain, Pseudomonas aeruginosa DR7, which was isolated from ponds. The equilibrium time of the adsorption process of living cells was much longer than that of non‐living cells, which was about 240 min, which indicates that living cells have intracellular accumulation and delay the adsorption process. Living cells favored a pH of 6.0, while non‐living cells showed higher efficiency at pH 7.0, demonstrating the pH‐dependent nature of metal biosorption. In this context, the maximum biosorption capacities for cadmium using non‐living cells and living cells were 103.8 mg/g and 70.94 mg/g, under cell mass of 1.0 g/L, pH 7.0, initial metal concentration of 200 mg/L, and contact time of 240 min, respectively. Cadmium biosorption by living cells was more accurately described by the Freundlich isothermal model, whereas the Langmuir model was used for non‐living cells. Living cells tend to show pseudo‐second‐order kinetic adsorption behavior, while non‐living cells tend to show pseudo‐first‐order kinetic adsorption behavior. Fourier‐transform infrared spectroscopy (FTIR) analysis suggested that the hydroxyl, amino, and carboxyl groups all play a role in biosorption. Scanning electron microscopy (SEM)–energy dispersive x‐ray spectroscopy (EDS) showed that the high‐temperature treatment destroys the integrity of the cell wall, which enhances the permeability of the cell wall, thus increasing the biosorption of Cd (II) by the non‐living cells. The study found that P. aeruginosa DR7 with high temperature inactivation has a higher Cd(II) adsorption capacity than living cells, making it a green and environmentally friendly biological adsorbent for wastewater treatment with heavy metals.

Strychnos potatorum seeds derived magnetic graphene oxide nanocomposite for removal of nickel from wastewater: Adsorption performance, isotherm, kinetic and desorption behavior

In the present study investigates the adsorption of nickel ions by Strychnos potatorum seeds derived magnetic graphene oxide (SP-MGO). The fitness of the derived material was analyzed using BET and zeta seizer which proves the suitability of this adsorbent for adsorption process. The surface area, pore size and pore volume were obtained through BET analysis and the results were 51.798 (m2/g), 16.795 nm and 0.217 (cm3/g) respectively. And the size of the nanoparticle was measured using zeta seizer. For achieving maximum adsorption capacity, the following optimized conditions were; 60 min of contact time, under pH of 8, with 10 mg of SP-MGO dose, for the concentration of 10 mg/l, at the temperature of 35 °C. Freundlich isotherm (R2 =0.999) and pseudo second order (R2 =0.997) was well described the adsorption process. According to the isotherm model the adsorption of nickel ions occurs by multilayer of adsorption on heterogeneous surface of SP-MGO nanoadsorbent and also by chemisorption according to kinetic model. The Langmuir monolayer adsorption capacity (Q max) obtained by SP-MGO was 6.66 mg/g. The regeneration ability of SP-MGO was only reduced 17.1 % even after five cycles of adsorption runs. Overall, the SP-MGO can be a potential option for develop into a commercial adsorbent for industrial use to eliminate the pollutants from waste water.

Facile fabrication of sulfonated porous yeast carbon microspheres through a hydrothermal method and their application for the removal of cationic dye

Water pollution containing dyes become increasingly serious environmental problem with the acceleration of urbanization and industrialization process. Renewable adsorbents for cationic dye wastewater treatment are becoming an obstacle because of the difficulty of desorbing the dye from the adsorbent surface after adsorption. To overcome this dilemma, herein, we report a hydrothermal method to fabricate sulfonic acid modified yeast carbon microspheres (SA/YCM). Different characterization techniques like scanning electron microscopy, FTIR spectroscopy, and X-ray diffraction have been used to test the SA/YCM. Decorated with sulfonic acid group, the modified yeast carbon microspheres possess excellent ability of adsorbing positively charged materials. The removal rate of Methyl blue (MB) by renewable adsorbent SA/YCM can reach 85.3% when the concentration is 500 mg/L. The SA/YCM regenerated by HCl showed excellent regeneration adsorption capacity (78.1%) after five cycles of adsorption–desorption regeneration experiment. Adsorption isotherm and kinetic behaviors of SA/YCM for methylene blue dyes removal were studied and fitted to different existing models. Owing to the numerous sulfonic acid groups on the surface, the SA/YCM showed prominent reusability after regeneration under acidic conditions, which could withstand repeated adsorption–desorption cycles as well as multiple practical applications.

Efficient Recovery of Phosphate from Water Media by Iron-Magnesium Functionalized Lignite: Adsorption Evaluation, Mechanism Revelation and Potential Application Exploration.

Selective phosphorus removal from aquatic media has become an ideal strategy to mitigate eutrophication and meet increasingly stringent discharge requirements. To achieve phosphorus control and resource utilization of low-calorific-value lignite, iron and magnesium salts were used to functionalize lignite, and iron-magnesium functionalized lignite (called IM@BC) was prepared for phosphate recovery from water media. The adsorption properties of IM@BC were systematically evaluated, especially the influence of ambient pH and co-existing ions. The kinetic, isothermal, and thermodynamic adsorption behaviors of IM@BC were analyzed. The adsorption mechanism was revealed by microscopic characterization. The potential application of phosphate-containing IM@BC (P-IM@BC) was explored. The results show that IM@BC has a strong phosphate adsorption capacity, and the maximum adsorption capacity is 226.22 mgP/g at pH = 3. Co-existing CO32- inhibits phosphate adsorption, while coexisting Ca2+ and Mg2+ enhance the effect. At the initial adsorption stage, the amount of phosphate adsorbed by IM@BC continues to increase, and the adsorption equilibrium state is gradually reached after 24 h. The adsorption process conforms to the pseudo-second-order kinetic model (PSO) and Langmuir isothermal adsorption model, and the adsorption process is mainly chemical adsorption. The phosphate absorption capacity is positively correlated with temperature (283.15 K~313.15 K), and the adsorption process is spontaneous, endothermic, and entropy-increasing. Its adsorption mechanism includes electrostatic attraction, ion exchange, surface precipitation, and coordination exchange. IM@BC can efficiently recover phosphate from actual phosphorus-containing wastewater with a recovery efficiency of up to 90%. P-IM@BC slowly releases phosphate from pH 3 to 11. Plant growth experiments showed that P-IM@BC could be used as a slow-release fertilizer to promote the root growth of cowpeas. The novelty of this work lies in the development of a highly efficient phosphate recovery adsorbent, which provides a feasible method of phosphorus control in water media and resource utilization of lignite.

Influence of Natural Colloids on the Kinetic Adsorption Behavior of Am(III) on Vadose Zone Sediments

Influence of Natural Colloids on the Kinetic Adsorption Behavior of Am(III) on Vadose Zone Sediments

Adsorption kinetics behavior of MB dye on CaO nanosheets

The work reported herein demonstrates the fabrication of CaO nanosheets employing a thermal decomposition method. The obtained CaO nanosheets were characterized using TEM, BET, XRD, EDX, and FTIR instruments. Moreover, the effect of initial dye concentration and pH on MB removal by CaO nanosheets was studied. The result showed that the nanoparticles have sizes around 100 nm, and the CaO nanosheets have an average diameter of 50 nm. Meanwhile, the average pore diameter and surface area of CaO are 15.847 Å and 5.881 m2. g−1 , respectively. Numerical models based on Temkin, Freundlich, and Langmuir were applied to adsorption data to better understand the MB dye adsorption onto CaO nanoparticles. The sorption findings demonstrated a stronger fit with the Temkin model (R2 = 0.983) compared to the Freundlich model (R2 = 0.947) and Langmuir model (R2 = 0.968). The maximum adsorption capacity of MB on the CaO nanoparticles is 688.01 mg/g. The investigation determined that the adsorption kinetics adhered to the Pseudo-second-order kinetic model(R2 =0.982).

Innovative approaches to suppress non-specific adsorption in molecularly imprinted polymers for sensing applications

Molecularly imprinted polymers (MIPs) are synthetic antibodies developed to bind selectively with specific molecules. They function through a particular recognition process involving their cavities and functional groups. Nevertheless, functional groups located outside these cavities are the main cause of non-specific molecule binding, thus reducing the effectiveness of MIPs in sensing applications. This work focused on enhancing the selectivity and performance of MIPs through electrostatic modification with surfactants. The study investigates the use of two surfactants, namely sodium dodecyl sulfate (SDS) and cetyl trimethyl ammonium bromide (CTAB), to eliminate non-specific adsorption in MIPs. The binding isotherms of the target molecule sulfamethoxazole (SMX) on MIPs and non-imprinted polymers (NIPs) were analyzed, showing higher adsorption capacity of MIPs due to the specific cavities. The modification with SDS or CTAB effectively eliminated non-specific adsorption in MIPs. The kinetic adsorption behavior further demonstrated the efficacy of MIP+--SDS/CTAB in the selective adsorption of SMX. Calibration curves showcase the methodology's analytical capabilities, achieving low limit of detection for SMX 6 ng mL−1 using MIP +-SDS. The stability study confirmed that the developed MIP +/--SDS/CTAB remains stable even at high temperatures, demonstrating its suitability for on-site applications. The methodology was successfully applied to detect SMX in milk and water samples, achieving promising recoveries. Overall, the electrostatic modification of MIPs with surfactants emerges as a valuable strategy for enhancing selectivity and performance in target molecule recognition and detection.

Adsorption kinetics of CH4 and CO2 on shale: Implication for CO2 sequestration

The adsorption kinetic behavior of CH4 and CO2 in shale is critical for design and practice the CO2 sequestration with enhanced shale gas recovery. In this study, adsorption isotherms and kinetics curves of CH4 and CO2 in two shale samples were measured by the volumetric method at the temperature of 308.15 K, 323.15 K, 338.15 K and 353.15 K with the pressures up to 12 MPa. The pseudo-first-order (PFO) model, pseudo-second-order (PSO) model and Bangham model were used to describe the adsorption kinetics data. Furthermore, the influence of pressure and temperature on the adsorption kinetic behavior of CH4 and CO2 was clarified. The results show that the adsorption kinetic curves can be classified into three stages: rapid adsorption, slow adsorption and adsorption equilibrium stage. The fitting accuracy of the three kinetic models is in the order of Bangham > PSO > PFO. Moreover, the adsorption kinetics of CH4 and CO2 are highly dependent on pressure and temperature. The adsorption rate constant (kb) of CH4 and CO2 increases first and then decreases with increasing pressure. At the pressure below the supercritical pressure of CO2, the kb of CO2 shows a decreasing trend with the increase of temperature, which is the same as that of CH4. However, after exceeding the supercritical pressure of CO2, the variations in kb of CO2 with temperature presents an opposite trend as it increased with increasing temperature. Therefore, the pressure and temperature dependent adsorption kinetic behaviors requires consideration for optimizing engineering parameters in application of CO2 enhanced shale gas recovery and sequestration.

Olive stone as an eco-friendly bio-adsorbent for elimination of methylene blue dye from industrial wastewater

Adsorbents synthesized by activation and nanoparticle surface modifications are expensive and might pose health and ecological risks. Therefore, the interest in raw waste biomass materials as adsorbents is growing. In batch studies, an inexpensive and effective adsorbent is developed from raw olive stone (OS) to remove methylene blue (MB) from an aqueous solution. The OS adsorbent is characterized using scanning electron microscopy (SEM), Fourier Transform Infra-Red (FTIR), and Brunauer–Emmett–Teller (BET) surface area. Four isotherms are used to fit equilibrium adsorption data, and four kinetic models are used to simulate kinetic adsorption behavior. The obtained BET surface area is 0.9 m2 g−1, and the SEM analysis reveals significant pores in the OS sample that might facilitate the uptake of heavy compounds. The Langmuir and Temkin isotherm models best represent the adsorbtion of MB on the OS, with a maximum monolayer adsorption capacity of 44.5 mg g−1. The best dye color removal efficiency by the OS is 93.65% from an aqueous solution of 20 ppm at the OS doses of 0.2 g for 90 min contact time. The OS adsorbent serves in five successive adsorption cycles after a simple filtration-washing-drying process, maintaining MB removal efficiency of 91, 85, 80, and 78% in cycles 2, 3, 4, and 5, respectively. The pseudo second-order model is the best model to represent the adsorption process dynamics. Indeed, the pseudo second-order and the Elovich models are the most appropriate kinetic models, according to the correlation coefficient (R2) values (1.0 and 0.935, respectively) derived from the four kinetic models. The parameters of the surface adsorption are also predicted based on the mass transfer models of intra-particle diffusion and Bangham and Burt. According to the thermodynamic analysis, dye adsorption by the OS is endothermic and spontaneous. As a result, the OS material offers an efficient adsorbent for MB removal from wastewater that is less expensive, more ecologically friendly, and economically viable.

Synergetic effect between zeolite 5 A and maghemite nanoparticles for fast lead uptake from the Peruvian river Cumbaza: Study of surface adsorption mechanism using X-ray photoelectron spectroscopy

A novel magnetic composite of zeolite 5A and maghemite nanoparticles has been synthesized at 300 K and its lead removal properties from the Peruvian river Cumbaza were systematically studied. Its kinetic adsorption properties were investigated, and a fast equilibrium time of 15 min was achieved with 97% of removal and an adsorbent dose of 0.5 g L−1. A 100% Pb removal efficiency was reached by increasing the adsorbent dose to 1.0 g L−1, which concomitantly also removed iron species from the river aliquots. During the kinetic tests, the optimum pH was from 6.5 to 7.5, showing that no chemical reactant alteration was required to achieve a remarkable efficiency for the magnetic composite. The kinetic adsorption behavior matched well with the pseudo-first and second-order models. Post-adsorption analysis confirmed the presence of lead in all the samples. The combined results also demonstrated a synergetic response between lead and both adsorbent phases. The adsorption mechanism was governed by three steps, including inner surface complexation between lead species and maghemite, followed by lead cationic exchange between calcium-bulk and sodium-surface from zeolite 5A. Hence, this novel magnetic adsorbent exhibits a high lead removal efficiency, and it is easy-to-handle separation properties in real effluents.

Fabrication of agro–waste lotus leaf–derived adsorbent for effective removal of organic pollutants from water

Full utilization of agricultural waste (agro–waste)–derived adsorbents for water purification is favorably sustainable. Herein, adsorbents obtained from the local lotus leaves are employed to remove the organic pollutants from water. The local lotus–leaf–derived adsorbent followed by 2 g of ZnCl2 activation at 1173 K (LAC–2–1173) exhibits a maximum adsorption capacity of 91.7 mg∙g−1 for norfloxacin at 298 K due to its larger specific surface area and hydrophobicity. Meanwhile, LAC–2–1173 possesses a superior adsorption performance of methylene blue and methyl orange with the maximum adsorption capacity of 176.7 mg∙g−1 and 246.5 mg∙g−1, respectively. The pollutants’ adsorption over LAC–2–1173 is exothermic and spontaneous, and the adsorption kinetic behavior and adsorption isotherms are well in line with the pseudo–second–order equation and Langmuir model, respectively. This work provides some insight into the fabrication and utilization of local agro–wastes–derived materials for environmental remediation.

Sodium benzyl sulfonate functionalized-bentonite as a novel adsorbent for water softening process

In this work, novel Sodium benzyl sulfonate functionalized-bentonite (SBSB) adsorbent was synthesized through the reaction of bentonite with benzyl alcohol and chlorosulfonic acid. The prepared adsorbent was characterized using Low-angle XRD, FT-IR and TGA methods, and applied for the removal of calcium and magnesium ions from water solutions. The effect of contact time and initial hardness concentration on the hardness removal efficiency of the prepared adsorbents were studied. It was found that the adsorption was reached the equilibrium condition within about 60 min, and the maximum adsorption capacity (52.5 mg g−1) was achieved in the hardness of 150 mg L−1. Compared to pristine bentonite, the adsorption efficiency of SBSB was significantly enhanced, which is ascribed to the presence of benzyl sulfonate functional groups on its surface. The adsorption isotherm of calcium and magnesium ions on SBSB was described by Langmuir and its adsorption kinetic behavior followed pseudo-second-order model.