Fitted Langmuir Model Research Articles

Pristine and modified mucuna beans adsorptive studies of toxic lead ions and methylene blue dye from aqueous solution

In this study mucuna beans were used for the removal of toxic Pb(II) ions and methylene blue dye from aqueous solution. The use of mucuna beans in water treatment application is largely unexplored. Therefore the current study is the first ever to report on mucuna beans as potential adsorbents. Mucuna beans were tested as adsorbents in pristine and chemically treated form. Batch adsorption experiments were conducted to evaluate the effect of systematic parameters such as the initial concentration, temperature, contact time and pH. The adsorbents were characterized by scanning electron microscope (SEM), thermogravimetric analysis (TGA), X-ray diffraction (XRD), fourier transformed infrared (FTIR) and Brunauer-Emmet teller (BET). SEM images revealed that acetone treated mucuna beans (Ac-MB), methanol treated mucuna beans (Me-MB) and dimethylformamide treated mucuna beans (DMF-MB) morphologies were dominated by spherical microstructures. FTIR analysis affirmed the presence of oxygen containing functional groups such as (–OH), (–COOH) and (–CO) attached to the adsorbents surface. These groups could enhance the adsorption processes. BET results also suggested that treated mucuna beans exhibits large pores, which could easily trap Pb(II) ions and methylene blue dye. It was observed that uptake of Pb(II) and methylene blue increased with increase in initial concentration of solution. However, all adsorbents had higher adsorption capacity for methylene blue molecules than Pb(II) ions. Also adsorption rate of methylene blue was faster, achieving equilibrium in 20 min and Pb(II) ions in 90 min. Enhancing the temperature of the solution had a positive effect on the removal of Pb(II) ions by UT-MB and Ac-MB, while for methylene blue it was Me-MB and Ac-MB revealing the exothermic nature of the processes. However, increasing the temperature was detrimental on the adsorption of Pb(II) ions onto Me-MB, AA-MB and DMF-MB, for methylene blue it was onto DMF-MB, UT-MB and AA-MB revealing the endothermic nature of the processes. The maximum adsorption capacities were obtained at pH 9 for both pollutants, Pb(II) adsorption capacity trends were UT-MB > Ac-MB > DMF-MB > AA-MB > Me-MB (19.96, 18.94, 17.60, 16.17 and 16.15 mg/g) respectively and for methylene blue were Me-MB > DMF-MB > UT-MB > Ac-MB > AA-MB (24.56, 23.89, 22.86, 22.78 and 22.55 mg/g). Pb(II) adsorption onto all adsorbents fitted Freundlich model. Methylene blue adsorption onto UT-MB and Ac-MB fitted Langmuir model, while Me-MB, AA-MB and DMF-MB fitted Freundlich model. Kinetic studies revealed that all adsorption processes found good fit for PSO model. However, Pb(II) ions adsorption onto AA-MB and DMF-MB had good fit for PFO model. The reusability of the adsorbents was also tested.

Porous biochar modified with polyethyleneimine (PEI) for effective enrichment of U(VI) in aqueous solution

This study investigated the modification of moso bamboo biochar with polyethyleneimine (PEI) for the efficient enrichment of U(VI) in aqueous solution. The alkali/acid treated biochars with amine groups (PEI-alkali-biochar or PEI-acid-biochar) were characterized by SEM, BET, TGA, FTIR and XPS. The effects of contact time, U(VI) concentration, pH and ionic strength on U(VI) adsorption by PEI-alkali/acid-biochar were studied. U(VI) adsorption process on PEI-alkali/acid-biochar obeys pseudo-second-order model. Intraparticle diffusion model was used to investigate the controlled factors of the adsorption process. The fitting of Langmuir model gives the maximum adsorption capacities of 212.7 mg/g for PEI-alkali-biochar and 185.6 mg/g for PEI-acid-biochar, which are almost 9–10 times higher than that of pristine biochar (20.1 mg/g). The thermodynamic parameters illustrate that U(VI) adsorption on PEI-alkali/acid-biochar is an exothermic and spontaneous process. The FTIR and XPS analyses imply that U(VI) adsorption by PEI-alkali/acid-biochar is mainly controlled by complexation between U(VI) and amine groups. PEI-alkali/acid-biochar could be considered as a low-cost and outstanding material for U(VI) removal from radionuclide wastewater in practical application.

A novel graphene aerogel synthesized from cellulose with high performance for removing MB in water

A novel graphene aerogel has been synthesized from cellulose by an easy way through sol-gel reaction and carbonization. In this route, it can be found the products have a high yield about 48 % and form a specific porous networks assembled by graphene flake. The product sample like CGA-2, characteristic of a specific area about 1426.11 m2/g and total pore volume about 1.02 cm3/g, exhibits a remarkable performance for removing cationic dye like methylene blue (MB) in water. Of which the maximal MB adsorption capacity can be found about 610.85 mg/g in a neutral solution and 1.2 g/g in a basic solution. Under the condition of initial MB concentration of 100 mg/L and pH of 7.0, the adsorption equilibrium can be achieved on CGA-2 in 10 min, with MB removal ratio about 99 %. In the MB adsorption on CGA-2, the isotherm fits Langmuir model with correlation coefficient of 0.9905, and the kinetics follows pseudo-second-order model with correlation coefficient of 0.9999.

Preparation of Tungstotellurate(VI)-coated Magnetic Nanoparticles for Separation and Purification of Ovalbumin in Egg White

Abstract Tungstotellurate(VI)-coated magnetic nanoparticles (MNP) were prepared by immobilization of tungstotellurate(VI) salt onto the surface of branched polyethyleneimine (PEI)-modified magnetic nanoparticles via electrostatic interaction. The structure and composition of TeW@MNP were confirmed by characterization with FT-IR, EDS and SEM. The obtained TeW@MNP composite had proven to be a promising adsorbent for the adsorption of ovalbumin in egg whites. Approximately 0.5 mg of TeW@MNP composite gave rise to a maximum adsorption efficiency of 91.6% for 100 μg mL–1 ovalbumin in 200 mL of sample solution at pH 4.0 (BR buffer). The retained ovalbumin was readily recovered by using 0.1% SDS as a stripping reagent, providing a recovery of 98.1%. The adsorption behavior of ovalbumin fitted Langmuir model, corresponding to a theoretical adsorption capacity of 373 mg g–1. The TeW@MNP composite was practically applied to the selective isolation of ovalbumin from egg whites, and SDS-PAGE assay results clearly indicated that the ovalbumin with high purity was obtained. The above experimental results illustrated the great application potentials of polyoxometalates for protein isolation and purification and extended the application scope of polyoxometalates in life science field.

Supercritical CO2 Exposure-Induced Surface Property, Pore Structure, and Adsorption Capacity Alterations in Various Rank Coals

Carbon dioxide (CO2) has been used to replace coal seam gas for recovery enhancement and carbon sequestration. To better understand the alternations of coal seam in response to CO2 sequestration, the properties of four different coals before and after supercritical CO2 (ScCO2) exposure at 40 °C and 16 MPa were analyzed with Fourier Transform infrared spectroscopy (FTIR), low-pressure nitrogen, and CO2 adsorption methods. Further, high-pressure CO2 adsorption isotherms were performed at 40 °C using a gravimetric method. The results indicate that the density of functional groups and mineral matters on coal surface decreased after ScCO2 exposure, especially for low-rank coal. With ScCO2 exposure, only minimal changes in pore shape were observed for various rank coals. However, the micropore specific surface area (SSA) and pore volume increased while the values for mesopore decreased as determined by low-pressure N2 and CO2 adsorption. The combined effects of surface property and pore structure alterations lead to a higher CO2 adsorption capacity at lower pressures but lower CO2 adsorption capacity at higher pressures. Langmuir model fitting shows a decreasing trend in monolayer capacity after ScCO2 exposure, indicating an elimination of the adsorption sites. The results provide new insights for the long-term safety for the evaluation of CO2-enhanced coal seam gas recovery.

Adsorption of basic magenta on graphene oxide-modified sugarcane bagasse

A novel adsorbent was prepared using sugarcane bagasse modified with graphene oxide. The adsorbent was characterized using Fourier transform infrared spectroscopy, thermogravimetric analysis, scanning electron microscopy, and X-ray diffraction analyses. The adsorption of basic magenta on bagasse and graphene oxide-modified bagasse was systematically studied. The effects of initial concentration, adsorption time, adsorption temperature, and the amount of the adsorbent on the adsorption capacity were examined. Adsorption isotherms were described using both the Langmuir and Freundlich models. It was found that the Langmuir model fit well with the experimental data. The results revealed that the adsorption percentage of basic magenta increased from 55.4% to 99.5% under optimal adsorption conditions. The maximum absorption capacity was 145 mg/g.

Procion Blue H-5R functionalized cellulose membrane with specific removal of bilirubin

The specific removal of bilirubin is essential to cure hyperbilirubinemia. In this study, cellulose membranes were prepared by a phase inversion technique with surface functionalized Procion Blue H-5R (PB) for bilirubin adsorption. The chemical structures and morphologies of membranes were characterized by FITR, XPS and SEM. The immobilized PB amounts of membranes were investigated. Moreover the effects of immobilized PB amounts, initial concentration of bilirubin, NaCl concentration, pH value, recycle numbers and BSA concentration on adsorption capability of PB-immobilized cellulose membrane to bilirubin. Results showed that PB was immobilized onto the cellulose membrane surfaces and reached a maximum amount of 230 mg/g membrane. The bilirubin adsorption isotherm fitted Langmuir model well. Furthermore, the PB-immobilized membrane could specifically adsorb bilirubin in BSA/bilirubin mixed solution and bilirubin adsorption capacity reached 26 mg/g at pH 9.5. The membrane showed excellent reusability that the adsorption capability of bilirubin decreased 1.3% after 3 adsorption–desorption cycles. This work indicated that the Procion Blue H-5R can be expected as a ligand for specific removal of bilirubin.

Adsorption of Cd(II) From Aqueous Solutions by Modified Biochars: Comparison of Modification Methods

In this study, adsorption experiments on Cd(II) ions in aqueous solution by biochars pyrolyzed from millet bran (MBBC) at 400~800 °C were carried out and MBBC had superior adsorption performance at pyrolysis temperature of 600~800 °C. Then, biochars were modified by potassium permanganate (MBBC-PP), potassium ferrate (MBBC-PF), and citric acid (MBBC-CA). The results showed that the adsorption capacities of these adsorbents were in the order: MBBC-PP > MBBC-PF > MBBC-CA > MBBC. FT-IR, XRD, and Raman were used to determine the characteristics of biochars and explore the main adsorption mechanism causing by modification. These characterizations confirmed that manganese oxide and iron oxide particles were loaded on the surface of MBBC-PP and MBBC-PF, respectively. For MBBC-PP and MBBC-PF, the adsorption sites generated by the loaded metal oxides play more important role than other factors in Cd(II) adsorption. For MBBC-CA, surface functional groups were the main contributor during Cd(II) adsorption. Batch adsorption experiments demonstrate a Langmuir model fit for Cd(II). The sorption kinetics of Cd(II) on adsorbents follows pseudo-second-order kinetics. Modified biochars, especially the one modified by KMnO4, could act as effective alternatives to enhance heavy metals removal from aqueous solutions.

Controllable synthesis of Fe3O4-wollastonite adsorbents for efficient heavy metal ions/oxyanions removal.

Iron oxide, in the form of magnetite (MG)-functionalized porous wollastonite (WL), was used as an adsorbent for heavy metal ions (cadmium and nickel) and oxyanions (chromate and phosphate) removal from water. The porous WL was synthesized from calcium carbonate and siloxane by controlled sintering process using low molecular weight submicrosized poly(methyl methacrylate) as a pore-forming agent. The precipitation of MG nanoparticles was carried out directly by a polyol-medium solvothermal method or via branched amino/carboxylic acid cross-linker by solvent/nonsolvent method producing WL/MG and WL-γ-APS/MG adsorbents, respectively. The structure/properties of MG functionalized WL was confirmed by applying FTIR, Raman, XRD, Mössbauer, and SEM analysis. Higher adsorption capacities of 73.126, 66.144, 64.168, and 63.456mgg-1 for WL-γ-APS/MG in relation to WL/MG of 55.450, 52.019, 48.132, and 47.382mgg-1 for Cd2+, Ni2+, phosphate, and chromate, respectively, were obtained using nonlinear Langmuir model fitting. Adsorption phenomena were analyzed using monolayer statistical physics model for single adsorption with one energy. Kinetic study showed exceptionally higher pseudo-second-order rate constants for WL-γ-APS/MG, e.g., 1.17-13.4 times, with respect to WL/MG indicating importance of both WL surface modification and controllable precipitation of MG on WL-γ-APS.

Effects of pH, carbonate, calcium ion and humic acid concentrations, temperature, and uranium concentration on the adsorption of uranium on the CTAB-modified montmorillonite

With the aim of gathering uranium from ground aquatic environment in which uranium mainly occurs in negative species, the montmorillonite (MT) intercalated with cetyltrimethylammonium bromide (CTAB) was fabricated. X-ray diffraction and Fourier transform infrared spectroscopy were utilized to prove the entrance of CTAB into MT. Adsorption of uranium onto CTAB-MT was studied with respect to effect of pH, carbonate, calcium, humic acid, contact time, initial uranium concentration, and temperature. The adsorption negatively depended on pH, carbonate and calcium ion and humic acid concentrations. CTAB-MT had a higher uranium adsorption ability. The maximum monolayer uranium adsorption amount of CTAB-MT calculated by well fitted Langmuir model was determined as 213.31 mg g−1, preceding 82.17 mg g−1 of MT. The adsorption kinetics was well fitted by pseudo-second-order model. The uptake mechanism involved ion exchange and electrostatic attraction. The adsorption was endothermic and spontaneous. The results demonstrated CTAB-MT was promising to separate uranium from ground water.

Removal of Cr(VI) and Cu(II) from wastewater by an <i>Argopecten irradians</i> shell powder adsorbent

The ability of the shell powder of Argopecten irradians to remove Cr(VI) and Cu(II) ions from aquatic systems was evaluated. The adsorption efficiency was very high for Cu(II), at approximately 99.04%, while for Cr(VI), it was not higher than 24.03%. The adsorption rate of Cr(VI) was affected by the pH, feeding amount, stirring time, calcination temperature and initial Cr(VI) ion concentration. The experimental results indicate that the optimal Cr(VI) absorption rate was 32.86% of Cr(VI) within 1.5 h at a pH of 3 and a 200 mg/L initial Cr(VI) concentration on shell powder acidifie, using hydrochloric acid and calcination at 300°C to promote adsorption. Langmuir and Freundlich models were used to analyse the isotherm data of Cr(VI) and Cu(II). The Freundlich model was suited to Cr(VI) adsorption, while the Langmuir model fit Cu(II) adsorption.

Fabrication of mesoporous SiO2@SLS composite to remove organic pollutants: hydrogen bond-induced intriguing changes of solubility

Because biomass lignin shows good adsorption activity, its derivatives such as alkali lignin and kraft lignin have been applied in water treatment; however, sodium lignosulfonate (SLS), mainly limited by its high water solubility, is not applicable in this respect. In this work, we fabricated SiO2@SLS mesoporous adsorbent using a facile solution coating method by one step. SLS coating SiO2 enables the former to be “separated” from water, accomplishing the soluble to insoluble conversion. This change makes the composite more suitable and efficient to remove organic pollutants from water than the SLS precursor. It is found that interfacial hydrogen bonds play a significant role in the conversion, which is further corroborated by density functional theory calculations. Various characterizations show that SiO2@SLS is composed of uniform particles around 80 nm in size. Abundant mesopores with diameters ranging from 2 to 3 nm are found on the surface of SiO2@SLS nanoparticles. The specific surface areas of SiO2@SLS were measured between 293.4 and 33.2 m2 g−1, depending on the SLS amount used in the preparing process. Originating from the bio-adsorbent lignin precursor, the SiO2@SLS composite shows excellent adsorption property. Representatively, SiO2@SLS-0.6 is able to efficiently remove methylene blue (MB), almost twice as much as SiO2-0 does; its adsorption capacity (Qm) reaches 206.2 mg g−1 according to the Langmuir model fitting; notably, SiO2@SLS-0.6 works very well even in a high-concentration MB solution (50 mg L−1), showing removal efficiencies at 90.0% (within 1 h) and 99.9% (720 h, i.e., 30 days). Plus having remarkable adsorption stability, our composite SiO2@SLS is anticipated to be promising in application of polluted water treatment.

Compressible cellulose nanofibril (CNF) based aerogels produced via a bio-inspired strategy for heavy metal ion and dye removal

A sustainable nanomaterial, cellulose nanofibril (CNF) was used to prepare aerogel sorbents to remove various contaminants in wastewater. A mussel-inspired coating strategy was used to introduce polydopamine onto the surface of CNFs, which were cross-linked with polyethylenimine (PEI) to form the aerogels. The synthetic procedure was optimized to achieve a minimal consumption of raw materials to produce a robust porous structure. The aerogels possessed a low density (25.0 mg/cm3), high porosity (98.5%) and shape recovery in air and water. Adsorption studies were conducted on two representative contaminants, Cu (II) and methyl orange (MO). The kinetic data obeyed the pseudo 2nd order kinetic model and the mechanism of adsorption could be described by the intra-particle diffusion model. The Langmuir model fitting yielded a maximum adsorption capacity of 103.5 mg/g and 265.9 mg/g for Cu (II) and MO, respectively. The effects of pH on the adsorption performance were evaluated, confirming that the aerogels can maintain a high adsorption capacity over a wide pH range.

Removal performance of phosphorylated graphene oxide-chitosan composite towards Eu(III)

In this work, a novel phosphorylated graphene oxide (GO)-chitosan (CS) composite (denoted as GO-CS-P) was rationally prepared and applied for Eu(III) enrichment. According to the macroscopic experimental results, the sequestration of Eu(III) by GO-CS-P was ultrafast and the sorption equilibrium reached within 5 min. Based on Langmuir model fit, the maximum sorption capacity of Eu(III) at pH 5.5 and 293 K was calculated to be 106.14 mg/g, being higher than a variety of the previously reported materials. More importantly, GO-CS-P could effectively and selectively capture Eu(III) from the aqueous solution of high salinity and multiple components. The X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), X-ray absorption spectroscopy (XAS) and X-ray photoelectron spectroscopy (XPS) analyses suggested that Eu(III) mainly formed inner-sphere complexes with the surface phosphonate and carboxyl groups. Overall, the newly synthesized GO-CS-P composite possessed great application potential in the remediation of trivalent lanthanide/actinide-polluted groundwater.

Adsorption of basic and reactive dyes from aqueous solution onto Intsia bijuga sawdust-based activated carbon: batch and column study.

The adsorption behavior of basic, methylene blue (MB), and reactive, remazol brilliant violet 5R (RBV), dyes from aqueous solution onto Intsia bijuga sawdust-based activated carbon (IBSAC) was executed via batch and column studies. The produced activated carbon was characterized through Brunauer-Emmett-Teller (BET) surface area and pore structural analysis, proximate and ultimate, scanning electron microscopy (SEM), and Fourier transform infrared spectroscopy (FTIR). Batch studies were performed to investigate the effects of contact time, initial concentration, and solution pH. The equilibrium data for both MB and RBV adsorption better fits Langmuir model with maximum adsorption capacity of 434.78 and 212.77mg/g, respectively. Kinetic studies for both MB and RBV dyes showed that the adsorption process followed a pseudo-second-order and intraparticle diffusion kinetic models. For column mode, the breakthrough curves were plotted by varying the flow rate, bed height, and initial concentration and the breakthrough data were best correlated with the Yoon-Nelson model compared to Thomas and Adams-Bohart model. The adsorption activity of IBSAC shows good stability even after four consecutive cycles.

Macroscopic and molecular investigations of immobilization mechanism of uranium on biochar: EXAFS spectroscopy and static batch

A new environmentally friendly and low–cost adsorbent was produced from the camphor tree leaves (BC@CTL) and used to remove U(VI) from waste water via batch capture experiments under varying pH, time, and U(VI) concentration. The resultant biochar was characterized by SEM, BET, zeta-potentials, and FTIR spectroscopy. The capture process was strongly dependent on pH and independent of ionic strength. The capture experimental results indicated that U(VI) was quickly captured to BC@CTL with a maximum capture capacity of 0.41 mmol U(VI) g−1 obtained by Langmuir model fitting. The results of EXAFS analysis revealed that the interaction mechanism of U(VI) on the BC@CTL was primarily controlled by inner-sphere surface complexation. The investigation was meaningful for the “treating wastewater with wastes” strategy implementation, especially biochar can be regarded as a promising candidate for the pre-concentration and immobilization of radionuclides from aqueous solutions in environmental remediation.

Adsorptive Removal of Cr(VI) and Cu(II) Ions from Water Solution using Graphene Oxide–Manganese Ferrite (GMF) Nanomaterials

Chromium (Cr) and copper (Cu) are heavy metals known for their dangerous effect towards human health and could enter into human body mainly through ingestion. Over the years, different treatment methods have been used to eliminate heavy metal from raw water source and these include (co)precipitation, coagulation/flocculation, adsorption and ion- exchange. Nonetheless, adsorption is the most prominent method due to its high adsorption capacity and low cost. In this work, graphene oxide-manganese ferrite (GMF) nanomaterials were synthesized and used to remove Cr(VI) and Cu(II) ions from water solution based on adsorption mechanism. The synthesized nanomaterials were characterized using FTIR, BET and TEM prior to use in adsorption process. Batch adsorption studies were carried out to study the adsorption capacity and kinetic properties of the nanomaterials in eliminating two selective heavy metal ions. At optimum pH value, the maximum adsorption capacity for Cr(VI) and Cu(II) are 34.02 mg/g and 66.94 mg/g, respectively. The experimental data revealed that the adsorption isotherm best fitted Langmuir model and followed Pseudo second order.

Combined grand canonical Monte Carlo and finite volume method simulation method for investigation of direct air capture of low concentration CO2 by 5A zeolite adsorbent bed

A method that combines finite volume method (FVM) and grand canonical Monte Carlo (GCMC) method is proposed to investigate the direct air capture of low concentration CO2 by 5A zeolites in an adsorption bed of a space shuttle. In the FVM, the multicomponent Langmuir model and linear fitting formula are used to calculate saturation adsorption capacities and adsorption heat at macro-scale level, respectively. The GCMC method is used to obtain the parameters of the multicomponent Langmuir model and linear fitting formula at micro-scale level. The combined method overcomes the shortcomings of the saturation adsorption capacities and adsorption heat restricted by experiments or empirical formulas. The effects of inlet velocity, particle size, and porosity on heat and mass transfer in the adsorption bed are predicted. The saturation adsorption time for N2 is faster than that for CO2. The competitive adsorption process between CO2 and N2 is divided into three stages, namely, primary, intermediate, and saturation stage. The location of temperature difference peak between solid and gas phase moves toward the outlet of the adsorption bed with increasing velocity, porosity, adsorption time or decreasing particle size. An adsorption bed with high inlet velocity and porosity and small particle size is recommended to achieve improved performance.

Adsorption desulfurization of model gasoline by metal–organic framework Ni3(BTC)2

Abstract This work presented the synthesis of Ni-based metal-organic framework material with a paddle-wheel structure Ni3(BTC)2 (Ni-BTC) and its application in thiophene (TP) adsorption from gasoline distillate by batch method. Adsorption isotherms of TP, cyclohexene, and toluene in cyclohexane onto Ni-BTC were conducted at 298–308 K to interpret the different effect of cyclohexene and toluene on TP adsorption. The results showed that, compared with cyclohexene, toluene addition in model gasoline led to a more evident decline in sulfur capacity of Ni-BTC, which is opposite to isostructural HKUST-1. The adsorption isotherms of TP, cyclohexene and toluene fit Langmuir model, S-type model and Temkin model well, respectively, indicating that the adsorption mechanisms of TP and the two competitors are different from one another. The adsorption capacities on Ni-BTC followed the order of cyclohexene

Adsorption Characteristics of Methylene Blue on WO3 Nanorods Prepared by Microwave‐Assisted Hydrothermal Methods

Nanostructures of WO3 powders are selected as a dye adsorbent and investigated to understand the effects of specific surface area of WO3 nanorods on dye‐adsorption performance. The synthesis of WO3 nanorods is performed using microwave‐assisted hydrothermal methods within 5 min, with sodium tungstate dihydrate as a precursor and citric acid as a structure‐directing agent. The as‐synthesized WO3 nanorods are characterized by x‐ray diffraction, transmission electron microscopy, scanning electron microscopy, Fourier transform infrared (FT‐IR) spectroscopy, and Brunauer–Emmett–Teller (BET) measurements for their phases, structure, morphology, surface properties, and specific surface area, respectively. The dye‐adsorption performance is studied with a methylene blue (MB) solution using UV‐visible spectroscopy, and the results agreed well with the Langmuir model of adsorption. The maximum adsorption capacity of the WO3 nanorods was derived from Langmuir model's fitting. The specific surface area of WO3 powders synthesized at 150 °C is 52.05 m2 g−1; it tended to decrease with increasing synthesis temperature because of the stacking of nanorods. As a result, the adsorption performance of the WO3 nanorods is improved as the overall specific surface area increased.