Adams-Bohart Model Research Articles

Fixed bed adsorption of chromium and the Weibull function

Fixed bed adsorption of toxic metal ions such as chromium is a research area of current interest. Mathematical models are routinely used to summarize breakthrough results of metal ions, which often display varying degrees of curve asymmetry. This work introduces the Weibull function as a simple model for correlating asymmetric breakthrough curves of chromium. The Weibull function is similar to the widely used Bohart-Adams model in several aspects. For example, they both produce sigmoid or S-shaped curves. Their simple mathematical forms can be linearized and linear regression can then be used to estimate their parameters. However, the Weibull function, unlike the Bohart-Adams model, can track the trajectory of asymmetric breakthrough data. Applying the Weibull function to published breakthrough data of chromium, this article illustrates its outright superiority versus the Bohart-Adams model in representing highly asymmetric data. Both equations provide satisfactory fits to breakthrough data exhibiting a moderate degree of curve asymmetry.

Luminescent cellulose-based porous binary metal-organic gels in an adsorption bed for effective adsorption and sensitive detection of chlortetracycline hydrochloride

Three novel (Fe-Eu) JLUE-MOGs were successfully fabricated through a solvothermal method and employed to construct the double-effect system for antibiotics adsorption and detection. The characterizations highlighted the properties of ample active sites, large surface areas and hierarchical porous structures, which did contribute to superb and rapid chlortetracycline hydrochloride (CTC) adsorption by JLUE-MOGs. Besides, the effects of initial pH values, JLUE-MOG dosages and co-existing inorganic ions on the CTC adsorption could be explained by pore filling, π-π EDA interaction, electrostatic interaction, water affinity as well as hydrogen bonding. Moreover, the optimized condition was cross-explored by response surface methodology (RSM) with tiny differences compared to actual experiments. In addition, fluorescent JLUE-MOG-7 was implemented for sensitive recognition of CTC and reflecting adsorption processes. Furthermore, shaping JLUE-MOG-7@cellulose aerogels were fabricated as filter materials for applying into an adsorption bed. The breakthrough process was fitted well by Bohart–Adams model and Thomas model, along with recognizable fluorescence changes of immobilized adsorbents. This work develops efficient and luminescent powder-like JLUE-MOGs for antibiotics adsorptive enrichment and sensitive detection. More importantly, immobilized JLUE-MOG@cellulose aerogels, as promising and alternative adsorbents with real-time fluorescence changes, can be utilized for continuously pollutants removal in real wastewater treatment.

Fixed bed column performance of Tinospora cordifolia for defluoridation of water

Abstract A continuous adsorption study in a fixed-bed column was carried out by using Tinospora cordifolia as an adsorbent for the removal of fluoride from aqueous solution. The effect of flow rate, influent fluoride concentration and bed depth on the adsorption characteristics of adsorbent was investigated at pH 7. The dependencies of breakthrough curves on these parameters were confirmed from the data obtained. Modeling of data was done. Thomas, Yoon–Nelson and Adams–Bohart models were applied to experimental data to predict the breakthrough curves. These kinetic models were helpful to determine the characteristic parameters of column designing for defluoridation on a large scale. Thomas and Yoon-Nelson models were found to be more suitable for the description of the breakthrough curve than the Adams–Bohart model in the present study. It was concluded that the Tinospora cordifolia-packed column can be used for effective defluoridation of water.

Volcanic Rock Materials for Defluoridation of Water in Fixed-Bed Column Systems.

Consumption of drinking water with a high concentration of fluoride (>1.5 mg/L) causes detrimental health problems and is a challenging issue in various regions around the globe. In this study, a continuous fixed-bed column adsorption system was employed for defluoridation of water using volcanic rocks, virgin pumice (VPum) and virgin scoria (VSco), as adsorbents. The XRD, SEM, FTIR, BET, XRF, ICP-OES, and pH Point of Zero Charges (pHPZC) analysis were performed for both adsorbents to elucidate the adsorption mechanisms and the suitability for fluoride removal. The effects of particle size of adsorbents, solution pH, and flow rate on the adsorption performance of the column were assessed at room temperature, constant initial concentration, and bed depth. The maximum removal capacity of 110 mg/kg for VPum and 22 mg/kg for VSco were achieved at particle sizes of 0.075–0.425 mm and <0.075 mm, respectively, at a low solution pH (2.00) and flow rate (1.25 mL/min). The fluoride breakthrough occurred late and the treated water volume was higher at a low pH and flow rate for both adsorbents. The Thomas and Adams–Bohart models were utilized and fitted well with the experimental kinetic data and the entire breakthrough curves for both adsorbents. Overall, the results revealed that the developed column is effective in handling water containing excess fluoride. Additional testing of the adsorbents including regeneration options is, however, required to confirm that the defluoridation of groundwater employing volcanic rocks is a safe and sustainable method.

Performance Evaluation of Fixed Bed Column Packed with Ionic Liquid Impregnated Silica for Separation of Gadolinium and Neodymium from Aqueous Solutions

Application of fixed bed column for separation of gadolinium and neodymium ions from their aqueous solutions using cyphos IL-104 impregnated silica was investigated. The performance of separation of the two lanthanide elements was evaluated by determining the column capacity, the total quantity sorbed of metal ions, and the removal percentage. These indicative column performance parameters were evaluated in altered conditions including fixed bed height of 2.0 and 3.0 cm, flow rate of 1.0 and 2.0 mL/min, and solution feed concentration of 50 and 100 ppm. Breakthrough modeling of the sorption process across the column was performed by employing Thomas and Adams–Bohart models. It was found that it took less time to reach the breakthrough when the flow rate and initial concentration increased, while the height of the bed decreased. Also, the column capacity increased by increasing the bed depth, decreasing the flow rate, and increasing the initial metal ion concentrations. 0.1 M nitric acid was found to be the best media for the separation of Nd3+ and Gd3+ ions.

Analysis of measuring methods of the concentration of methylene blue in the sorption process in fixed-bed column

The wastewater from industry is contaminated with dyes, which should be removed in order to prevent environmental damage. This paper presents a method for removing methylene blue from an aqueous solution using a fixed-bed adsorption process onto sawdust. In the article, the method of continuous measurement of methylene blue concentration in the process of sorption on sawdust was used. The results were compared with the results obtained by the standard method of periodic testing of the dye concentration. Continuous measurement of the dye concentration after the sorption process provides the actual nature of the process and the method offers additional information about the process, as opposed to a periodic test in which the concentration of the ingredient gives only averaged results. The kinetics of the methylene blue sorption process at variable initial dye concentrations are presented. The initial concentration of methylene blue had a significant impact on the process breakthrough curve. The increase in concentration (range of 10–90 mg/dm3) caused the extension of the penetration zone of the dye mass, thus gradually adsorbing itself on the bed. In the study of kinetics, the Bohart–Adams model was the best fit.

Fixed Bed Column Studies for the Adsorption of Cadmium onto Cockle Shell (Anadara Granosa) Powder

Recently, the pollution of heavy metal ions is getting more attention due to economic development. A number of methods have been proposed for the removal of heavy metal ions in aqueous solutions, and the adsorption technique has been widely utilized due to the effectiveness and flexibility. Cockles are marine bivalve molluscs and their shells are discharged as waste by many restaurants and marine product manufacturers, which causes environmental problems. Cockle shells can be economically reused as an adsorbent for wastewater treatment. In this report, cockle shells were recycled as a material for the removal of cadmium (II) ion by adsorption in a fixed bed column. Experiments were designed according to the Box-Behnken scheme to investigate the effect of the column parameters such as inlet ion concentration, feed flow rate, and mass of adsorbent. The breakthrough curves from experiments were analyzed with Thomas, Bohart-Adams, and Yoon-Nelson models. The results also indicate that the powder derived from cockle shells can be used as a low cost and effective adsorbent for heavy metal removal such as cadmium in a fixed bed column. The observation suggests that the Thomas model and the Yoon-Nelson model are more suitable to predict the adsorption of cadmium (II) ions on onto cockle shell powder in fixed-bed operation mode.

Adsorptive removal of tetracycline and amoxicillin from aqueous solution by leached carbon black waste and chitosan-carbon composite beads

Carbon black waste as waste by-product of oil refineries, exhibits improved specific surface area and is rich in surface functional groups after leaching. In this work, both powdered leached carbon black waste (LCBW) and LCBW-chitosan composite beads prepared via instantaneous gelation method were utilized as adsorbent to study their adsorption capabilities and behaviors for removal of tetracycline (TC) and amoxicillin (Amox) in distilled and tap water. The characterization showed that LCBW is high in specific surface area (~375 m2/g) and contains carboxyl (‒COOH) and hydroxyl (‒OH) groups which are essential to the adsorption. Under the experimental conditions, adsorption capacities ranging from 12 to 205 mg/g were obtained. It was observed that the adsorption performance of powdered LCBW was enhanced by the cations presented in the tap water while the effect was insignificant to LCBW-chitosan beads. The kinetics studies showed that the adsorption of the studied antibiotics on powdered LCBW and composite beads fitted well with pseudo 1st-order and pseudo 2nd-order model, respectively. The fitting of intraparticle diffusion model showed that the adsorption process was not governed solely by intraparticle diffusion. LCBW-chitosan beads was used to investigate the continuous adsorption of TC in a fixed bed column and the experimental data was fitted to Adams-Bohart model and Thomas model.

Adsorptive removal of as (III) by aluminium Oxide/Hydroxide nanoparticles: Modelling of column studies

The main aim of present work is to assess the applicability of aluminium oxide/hydroxide nanoparticles (AHNP) based low cost adsorbent synthesized through electrochemical route in column mode of operation. The adsorbent was found to be efficient and cost effective for the removal of highly toxic and carcinogenic metalloid (As (III)) from groundwater. The synthesized adsorbent was used for the treatment of simulated contaminated groundwater having As (III) concentration equivalent to that present in the groundwater of rural areas of Rajnandgaon District of Chhattisgarh state of India where the presence of As (III) along with several other contaminants have been reported. The nanoparticles were characterized with various sophisticated analytical techniques including XRD, FESEM - EDX and BET surface area analysis. The adsorption experiments show satisfactory results for simulated groundwater samples and the concentration of As (III) was brought down to below permissible limit of 10 μg/L (as per the USEPA standard). In the column mode of adsorption, the effects of bed height on the removal of As (III) in the influent was studied. Various models like Thomas model, Yoon-Nelson model and Adam-Bohart model were used to determine various constants related to maximum adsorption capacity of the adsorbent, time required for attaining 50% breakthrough curve (τ) and adsorption capacity coefficient. The Thomas model estimated the maximum adsorptive capacity of the AHNP adsorbent as 1309.8 µg/g for As (III) at the influent flowrate of 0.28 ml/min (with R2 value 0.93). The value of τ for AHNP adsorbent is found as 44153.5 min. Current studies indicate that groundwater contamination with As (III) can be managed by upscaling the AHNP as an efficient treatment solution.

Adsorptive column studies for removal of acid orange 7 dye using bagasse fly ash

Increasing industrialization creates a large scale of pollution and affects the availability of usable water. Dyes in wastewater are a visible pollutant, difficult to treat, and are toxic in nature. Amongst all the physicochemical methods, adsorption is the extensively applied process for the aqueous removal of dye. In the present study; the Bagasse Fly Ash (BFA) is used as an adsorbent for aqueous removal of Acid Orange dye in packed bed adsorption technique. The packed bed studies for different bed heights, influent concentration and flow rate are performed. The efficacy of packed columns is investigated using different models namely Bed depth service time, Thomas, Wolborsaka, Yoon-Nelson, and Bohart-Adams Models. The maximum adsorption capacity of BFA for 50% saturation of column is calculated to be 38 (mg/g) which shows BFA as a good adsorbent for dye removal.

Removal of Pb2+ Ions by ZSM-5/AC Composite in a Fixed-Bed Bench Scale System

This investigation suggests the implementation of ZSM-5 activated carbon composite as a prolific adsorbent for the continuous elimination of Pb2+ ions from water. Continuous adsorption experiments were performed by varying three parameters such as process flow rate (2-6 mL min-1), bed height (2-6 cm), and initial concentration (250–750 mg L-1). The highest loading capacity of the fixed-bed 213.3 mg L-1 was achieved with optimal values of 2 mL min-1 of flow rate, bed height of 6 cm, and initial concentration of 750 mg L-1, respectively. The breakthrough curves and saturation points were found to appear quickly for increasing flow rates and initial concentration and vice versa for bed depth. The lower flow rates with higher bed depths have exhibited optimal performances of the fixed-bed column. The mechanism of adsorption of Pb2+ ions was found to be ion exchange with Na+ ions from ZMS-5 and pore adsorption onto activated carbon. The breakthrough curves were verified with three well-known mathematical models such as the Adams-Bohart, Thomas, and Yoon-Nelson models. The later models showed the best fit to the column data over the Adams-Bohart model that can be utilized to understand the binding of Pb2+ ions onto the composite. Regeneration of ZSM-5/activated carbon was achieved successfully with 0.1 M HCl within 60 min of contact time. The outcomes conclude that ZSM-5 activated carbon composite is a prolific material for the continuous removal of water loaded with Pb2+ ions.

Separation of Cd (II) onto Polypyrrole nitrogen porous carbon composite in the continuous column system

Polypyrrole nitrogen porous carbon composite (PP/N-PCC) was prepared from molasses of the sugarcane industry. PP/N-PCC was characterized and used in the cadmium removal from the aqueous feed in a column system. The inlet metal concentration, flow rate, bed depth and pH were studied. Removal percent was reached 71.45% with a sorption capacity of 233.54 mg/g at pH5, 10 ml/min, and 7.5 bed depths. The column system was modelled using Thomas, Adams-Bohart and Yoon-Nelson kinetic models. The higher R 2 > 0.98 indicates that the Thomas model appeared to a well-fitting with the experimental outcomes. PP/N-PCC adsorbent appeared well recycled up to 8 cycles indicating the economic feasibility of PP/N-PCC in the separation of Cd (II) ions from liquid wastes.

Batch and column mode removal of the turquoise blue (TB) over bio-char based adsorbent from Prosopis Juliflora: Comparative study

Biochar, created from Prosopis Juliflora (B-PJ) through an ionic polymerization route, was utilized as a sorbent to remediate turquoise blue (TB). The biochar was described utilizing Fourier change infrared spectroscopy. The effects of operating factors such as flow rate, bed depth, concentration, and solution pH were investigated in column mode. Thomas, Yoon-Nelson, and Adams-Bohart models were applied to examine the experimental column data and the correlation between operating factors. The greatest adsorption limit of the BPJ was discovered utilizing 200 mg/L of the adsorbate, B-PJ portion 3 g, at a contact time of 150 min and pH of 6. The adsorption energy and harmony isotherms were all around spoken to by the pseudo-second-request model and the Langmuir model, separately. The most extreme adsorption limit acquired from the Langmuir isotherm model was 0.005173 mg/g. The test energy information dissected utilizing various models featured that the pseudo-second request motor model created a prevalent depiction of the trial information. The adsorption energy followed a pseudo-second-request active model with high connection coefficients (R2 ˃0.98). These outcomes showed that alginate immobilized biochar is earth well-disposed locally accessible, powerful and practical adsorbent for the expulsion of TB color from modern wastewaters.

Adsorption of phosphate on iron-coated sand granules as a robust end-of-pipe purification strategy in the horticulture sector

Nutrient enrichment in water bodies, and its detrimental consequences, are a well known and worldwide environmental problem. Agricultural activities are identified as an important source of diffuse losses of phosphate and nitrate because of the leaching out fertilizers from agricultural fields. This study encompasses the implementation of an end-of-pipe treatment by capturing phosphate from greenhouse effluent, using granular iron-coated sand (ICS) in an adsorption process. ICS is evaluated as a low-cost by-product because of its adsorption capacity and kinetics. The Langmuir isotherm was suitable for describing the adsorption thermodynamics. The adsorption capacity at an equilibrium concentration Ce of 25 mg PO4–P/L ranged between 1.85 and 3.07 mg PO4–P/g sorbent. Furthermore, both the pseudo-second-order model (R2 = 0.9823) and the Elovich model (R2 = 0.9803) showed a good fit with the kinetic data over the time range investigated, indicating that chemisorption is the rate-limiting step controlling the adsorption process. Higher adsorption capacities were observed at lower initial pH. Continuous bench-scale column experiments were performed to verify the adsorption potential of a filter bed under flow-through conditions, and the experimental data were fit to the Bohart-Adams model. Additionally, a discontinuous feeding regime of the column, resulting in intermediate resting periods, was introduced and showed an enhanced adsorption efficiency over a longer period. Finally, a pilot-scale experiment showed the potential of the ICS for the removal of phosphate from greenhouse effluent. The adsorption process, moreover, enables the recovery of phosphate via efficient desorption.

Evaluation of Lead (Pb(II)) Removal Potential of Biochar in a Fixed-bed Continuous Flow Adsorption System.

Background.Lead (Pb(II)) exposure from drinking water consumption is a serious concern due to its negative health effect on human physiology. A commercially available filter uses the adsorption potential of activated carbon for removing heavy metals like Pb(II). However, it has some constraints since it uses only surface area for the adsorption of these contaminants. Biochar produced via slow pyrolysis of biomass shows the presence of oxygen-containing functional groups on its surface that take part in the adsorption process, with higher removal potential compared to activated carbon.Objectives.The current study examined the adsorption kinetics and mechanisms of Pb(II) removing potential of biochar from water using a fixed-bed continuous flow adsorption system.Methods.The effect of initial Pb(II) concentration, mass of adsorbent (bed depth), and flow rate on adsorption potential were evaluated. The Adams-Bohart model, Thomas model, and Yoon-Nelson model were applied to the adsorption data.Results.The maximum removal efficiency of Pb(II) was 88.86 mg/g. The result illustrated that the Yoon-Nelson model is the best fit to analyze the adsorption phenomena of Pb(II) in a fixed-bed biochar column.Conclusions.The breakthrough data obtained from this study can be utilized to design a point of use filter that would be able to effectively remove Pb(II) from drinking water.Competing Interests.The authors declare no competing financial interests.

Modified Spruce Sawdust for Sorption of Hexavalent Chromium in Batch Systems and Fixed-Bed Columns.

This study investigated the potential use of spruce sawdust that was pretreated with diethylene glycol and sulfuric acid for the removal of hexavalent chromium from wastewater. The sawdust pretreatment process was conducted at different temperatures and times. The adsorbent was characterized by quantitative saccharification, scanning electron microscopy, and Brunauer–Emmet–Teller surface area analysis. Adsorption capacity was studied for both batch and column processes. The experimental adsorption isotherms were simulated using seven isotherm models, including Freundlich and Langmuir models. By using the Langmuir isotherm model, the maximal Cr(VI) adsorption capacity of organosolv-pretreated spruce sawdust (qm) was 318.3 mg g−1. Furthermore, the kinetic data were fitted to Lagergren, pseudo-second-order, and intraparticle diffusion models, revealing that the adsorption of Cr(VI) onto spruce sawdust pretreated with diethylene glycol and sulfuric acid is best represented by the pseudo-second-order kinetic model. Three kinetic models, namely, the Bohart–Adams model, Thomas model, and modified dose–response (MDR) model, were used to fit the experimental data obtained from the column experiments and to resolve the characteristic parameters. The Thomas adsorption column capacity of the sawdust was increased from 2.44 to 31.1 mg g−1 upon pretreatment, thus, demonstrating that organosolv treatment enhances the adsorption capability of the material.

High-efficiency removal of low-concentration Hg(II) from aqueous solution by bentonite nanocomposite: Batch and fixed-bed column adsorption study

ABSTRACT A nanocomposite based on bentonite was synthesized. Its adsorption properties for Hg(II) were evaluated by batch and fixed-bed column adsorption experiments. The results showed that the nanocomposite was an efficient adsorbent for the treatment of wastewater containing low-concentration Hg(II). It removed more than 92% of Hg(II) from aqueous solution with a pH ranged from 4.00 to 12.00. Its adsorption capacity for Hg(II) increased linearly with the increase of mercury concentration. The nanocomposite had excellent reusability. HCl solution can be used to elute Hg(II) ions loaded. The developed Bohart–Adams model can be used for the design of adsorption column.

Inhibitory effects of Ca2+ on ammonium exchange by zeolite in the long-term exchange and NaClO–NaCl regeneration process

The inhibitory effects of calcium ion (Ca2+) on ammonium (NH4+) exchange by zeolite were investigated in the long-term exchange and sodium hypochlorite - sodium chloride (NaClO–NaCl) regeneration process, and alleviation measure was developed and validated in this study. The batch experiments indicated that NH4+ removal efficiency, exchange kinetics and equilibrium isotherms were significantly dependent on the coexisting Ca2+. The exchange capacity decreased from 0.58 to 0.40 mg g−1 by increasing initial Ca2+ concentration from 0 to 100 mg L−1. The inhibitory effect of Ca2+ on NH4+ exchange efficiency was fitted to the competitive inhibition Monod model with half-saturation rate constant of 134.7 mg L−1. Ca2+ addition reduced the NH4+ removal rate and lengthened the exchange equilibrium time of zeolite. Periodic precipitation of Ca2+ in the form of calcium carbonate from the used regenerant maintained the removal efficiency of NH4+ commendably by alleviating inhibition effect of Ca2+ and extended the working life of zeolite. The major chemical compositions of natural and regenerated zeolite were basically unchanged. Compared to Bohart-Adams model and Thomas model, the Dose-Response model could predict the breakthrough curve well, and the fitted parameter further confirmed that NaClO–NaCl regeneration with periodic Ca2+ removal is an effective method to maintain efficient NH4+ from wastewater by zeolite.

Comparative adsorption of ciprofloxacin on sugarcane bagasse from Ecuador and on commercial powdered activated carbon

This work examined the adsorption capacity of sugarcane bagasse (SB) for the removal of ciprofloxacin (CPX) from water using batch experiments and a fixed bed column and compared its adsorption performance with a powdered activated commercial carbon (PAC). Both adsorbents achieved a similar percentage removal of about 78% with doses of 3 g L−1 of SB and 0.3 g L−1 of PAC (20 mg L−1 initial CPX concentration at 30 °C). The maximum removal was obtained at a pH between 6 and 8. SB adsorption isotherms were fitted to the Langmuir, BET and Freundlich models showing a maximum adsorption capacity of 13.6 mg g−1. The kinetic data for both SB and PAC fitted the pseudo second-order model (R2 = 0.99). The adsorption process was faster on the SB (65% of elimination in the first 5 min) than on the PAC. The study of the adsorbent properties shows that SB is a macroporous solid with a specific surface area 250 times smaller than PAC. The thermodynamic results show that SB adsorption was physical and exothermic. The main suggested interactions between CPX and SB are electrostatic attraction, hydrogen bonding and dipole-dipole interactions. The experiments carried out in a fixed bed show that the adsorption capacity at breakthrough increases with the bed height. The adsorption capacity at saturation time was 9.47 mg g−1 at a flow rate of 3 mL min−1, a bed height of 14 cm, and a diameter of 1.5 cm. The experimental data were fitted to the Bohart-Adams model (R2 = 0.98). These results highlight the capacity of sugarcane bagasse to adsorb ciprofloxacin from water, illustrating its potential as a low-cost adsorbent.

Evaluation of different forms of Egyptian diatomite for the removal of ammonium ions from Lake Qarun: A realistic study to avoid eutrophication

Three types of diatomite-based adsorbents—diatomaceous earth (DE), purified diatomite (PD), and diatomite@MgO/CaO (D@MgO) were used for adsorption decontamination of ammonium from Lake Qarun water (28.7 mg/L). The adsorption properties of the three diatomite-based adsorbents were evaluated by both batch and fixed-bed column adsorption studies. The kinetic results demonstrated removal percentages of 97.2%, 69.5%, and 100% using DE, PD, and D@MgO, respectively, at a 1 g/L adsorbent dosage. The adsorption results using DE and D@MgO showed the best fitness with pseudo-first-order kinetic and Langmuir isotherm models, while the obtained results using PD demonstrate better fitness with the Freunlidich model. The recognised fitting results with the pseudo-first-order model and estimated adsorption energies demonstrated physical uptake of ammonium by DE (5.93 kJ/mol), PD (4.05 kJ/mol), and D@MgO (7.81 kJ/mol). The theoretical maximum ammonium uptake capacity of DE, PD, and D@MgO were 63.16 mg/g, 59.5 mg/g, and 78.3 mg/g, respectively. Using synthetic adsorbents in a fixed-bed column system for treating ammonium ions in Lake Qarun water resulted in removal percentages of 57.4%, 53.3%, and 62.6% using a DE bed, PD bed, and D@MgO bed, respectively, after treating approximately 7.2 L of Lake Qarun water using a bed thickness of 3 cm, a flow rate of 5 mL/min, pH 8, and the determined ammonium concentration in Lake Qarun water (28.7 mg/L). The curves demonstrated breakthrough times of 900 min, 900 min, and 960 min for the DE bed, PD bed, and D@MgO bed, respectively, with 1440 min as the saturation time. The columns’ performances also were studied based on the Thomas model, the Adams-Bohart model, and the Yoon-Nelson model.