Adsorption Properties Of Pb Research Articles

Adsorption properties of Pb(II) and Cd(II) in acid mine drainage by oyster shell loaded lignite composite in different morphologies

A new idea to alleviate environmental pollution is the development of low-cost adsorbents using natural minerals and fishery wastes to treat high concentrations of heavy metal pollutants in acid mine drainage (AMD). Adsorbent morphology, adsorptive and regenerative capacity, and application potential are limiting factors for their large-scale use. Oyster shells capable of releasing alkalinity were loaded on the surface of lignite to develop two composite adsorbents with different morphologies (powdery and globular) for the treatment of AMD containing Pb(II) and Cd(II). The results show that the ability of the adsorbent to treat AMD is closely related to its morphologies. The pseudo-second-order kinetic model and the Langmuir model are suitable to describe the adsorption process of OS-M(P), and the maximum adsorption saturation capacities of Pb(II) and Cd(II) are 332.6219 mg/g and 318.9854 mg/g, respectively. The pseudo-second-order kinetic model and the Freundlich model are suitable to describe the adsorption process of OS-M(G). A synergistic result of electrostatic adsorption, neutralization precipitation, ion exchange and complex reaction is achieved in the removal of Pb(II) and Cd(II) by two morphologies of adsorbents. The regeneration times (5 times) and recovery rate (75.75%) of OS-M(G) are higher than those of OS-M(P) (3 times) and recovery rate (20%). The ability of OS-M(G) to treat actual AMD wastewater is still better than that of OS-M(P). OS-M(G) can be used as a promising environmentally friendly adsorbent for the long-term remediation of AMD. This study provides a comprehensive picture of resource management and reuse opportunities for natural mineral and fishery wastes.

New organo-mineral materials based on silica gels modified in situ with nitrogen-containing polymers: synthesis and adsorption properties for Pb(ІІ), Сu(ІІ), Cd(II), and Fe(III) ions

Three new organo-mineral composite materials were obtained by in situ immobilization of polymers containing azo-, nitro-, and oxyquinoline groups in various combinations on the surface of silica gel. The fact of modification of the silica gel surface by nitrogen-containing polymers was confirmed by IR spectroscopy and thermogravimetric analysis combined with mass spectrometry. The SEM-photo analysis of the surface of the synthesized composites allows us to state that all in situ immobilized polymers are on the surface of silica gel in the form of individual convex formations that practically do not affect the structure of the original silica gel. Regarding Fe(III) cations, all composites showed an increase in sorption capacity by 4.5–6.4 times compared to the original silica gel and did not reveal additional sorption activity compared to the original silica gel for Cd(II) and Pb(II) ions. Regarding Cu(II) ions, an increase in the sorption capacity by more than five times compared to the original silica gel was observed for the composite with in situ immobilized poly-5-(4-nitro)phenylazo-8-methacryloxyquinoline only.

Preparation of manganese-oxides-coated magnetic microcrystalline cellulose via KMnO4 modification: Improving the counts of the acid groups and adsorption efficiency for Pb(II)

Herein, the manganese-oxides-coated magnetic microcrystalline cellulose (MnOx@Fe3O4@MCC) was prepared by coprecipitation and subsequently modified with KMnO4 solution at room temperature, which was in turn applied for the removal of Pb(II) from wastewater. The adsorption properties of Pb(II) on MnOx@Fe3O4@MCC were investigated. The kinetics and isothermal data of Pb(II) were described well by the Pseudo-second-order model and the Langmuir isotherm model, respectively. At pH = 5, 318 K, the Langmuir maximum Pb(II) adsorption capacity of MnOx@Fe3O4@MCC was 446.43 mg/g, which is higher than many documented bio-based adsorbents. The results of Fourier transform infra-red and X-ray photoelectron spectroscopy indicated that the adsorption mechanisms for Pb(II) mainly involved surface complexation, ion exchange, electrostatic interaction and precipitation. Interestingly, the increased amount of carboxyl group on the surface of microcrystalline cellulose modified by KMnO4 was one of the important reasons for the high Pb(II) adsorption performance of MnOx@Fe3O4@MCC. Furthermore, MnOx@Fe3O4@MCC exhibited excellent activity (70.6 %) after five consecutive regeneration cycles, indicating its high stability and reusability. Endorsing to the cost-effectiveness, environmentally friendliness, and reusable nature, MnOx@Fe3O4@MCC can be counted as a great alternative contender for the remediation of Pb(II) from industrial wastewater.

Nanoscale Zero-Valent Iron Dispersed by Sodium Alginate Enables Highly Efficient Removal of Lead (Pb) from Aqueous Solution

Nanozero-valent iron (NZVI) shows great potential in the remediation of water pollution, but its application is limited by its instability and tendency to aggregate. To enhance the dispersibility and antioxidant properties of NZVI, we prepared composites (SN) by wrapping NZVI with sodium alginate (SA) for the removal of Pb(II) from water. Various characterization methods such as SEM-EDS, BET, XPS, and FT-IR were used to study the structure of the materials, and the adsorption properties of Pb(II) in the materials were analyzed using adsorption kinetics and adsorption isotherm experiments. The results showed that SN had a specific surface area of 47.05 m2/g, which was significantly higher than the 7.56 m2/g of NZVI, and the surface passivation was reduced. The maximum adsorption amount of SN on Pb(II) was obtained by fitting the adsorption isotherm model at 70.92 mg/g. After five cycles of adsorption, SN exhibited a removal rate of 95.11% for Pb(II). The mechanism of Pb(II) removal by SN involved the synergistic effect of electrostatic adsorption, redox reaction, ion exchange, and coprecipitation. Notably, even after 90 days of aging, the removal rate of Pb(II) by SN remained high at 95.39%, demonstrating good reactivity. These results indicated that SN is an effective adsorbent to remove Pb(II) contamination.

Pb(II) Adsorption of Composite Alginate Beads Containing Mesoporous Natural Zeolite.

Natural zeolite beads were prepared by encapsulating mesoporous zeolite into alginate beads via egg box method and its adsorption properties of Pb(II) ions were investigated in aqueous solution. Crystallinity and size reduction of natural zeolite were enhanced by mechanic modification of the ball milling process. FTIR and SEM-EDS analyses confirmed that mechanically modified zeolite particles were incorporated into alginate hydrogel. The highest adsorption amount of zeolite alginate beads was 87.47 mg/g after 20 h adsorption process. SEM-EDS result confirmed that the adsorption process has occurred on the surface of zeolite alginate beads. Adsorption kinetic data were fitted with Langmuir adsorption isotherm which showed that Pb2+ cation adsorbed into monolayers of adsorbent material. Moreover, we observed that calcium ion released after the Pb2+ adsorption process in the feed solution. Therefore, the adsorption mechanism of zeolite alginate beads explained by complex mechanisms including surface sorption and ion exchange of Pb2+ and Ca2+ in beads.

Preparation of Modified Watermelon Biochar and Its Adsorption Properties for Pb(Ⅱ)

In this study, watermelon rind was used as a raw material to modify watermelon rind biochar (MBC) with ammonium sulphate[(NH4)2S] for adsorption of Pb(Ⅱ) ions. The effects of solution pH, adsorption time, adsorbent addition amount, initial mass concentration of Pb(Ⅱ) ions, and ionic strength on the adsorption of Pb(Ⅱ) ions were investigated. The results show that the saturated adsorption time was 5 h, the optimum pH of the adsorption reaction was 6, and when the initial mass concentration of Pb(Ⅱ) ions were 1000 mg·L-1, and the amount of adsorbent was 2.0 g·L-1. The maximum adsorption amount of MBC to Pb(Ⅱ) ions can reach 97.63 mg·g-1, which is significantly higher than unmodified watermelon husk biochar (BC). The adsorption of Pb(Ⅱ) ions by modified watermelon biochar was in accordance with the Langmuir isotherm adsorption model and the pseudo second-order kinetic model, which proves that adsorption is dominated by monolayer chemical adsorption. The desorption of MBC after adsorption of Pb(Ⅱ) ions was carried out using a sodium hydroxide solution to study the reusability of MBC, and the adsorption amount was still 64.74 mg·g-1 in the sixth cycle. Characterization and analysis of adsorbents by Fourier transform infrared spectroscopy, X-ray photoelectron spectroscopy, nitrogen adsorption, scanning electron microscopy-energy spectroscopy, zeta potential analysis, and X-ray diffraction (XRD) were carried out, which showed that the adsorption mechanism is mainly that MBC oxygen- and MBC sulfur-containing groups adsorb Pb(Ⅱ) through complexation and precipitation. Therefore, ammonium sulfide modified watermelon rind biochar can be used as a highly efficient lead adsorbent.

Preparation of the crosslinked GO/PAA aerogel and its adsorption properties for Pb(II) ions

The graphene oxide(GO)/polyacrylic acid(PAA) was prepared by in situ polymerization in graphene oxide lamellae, and crosslinked graphene oxide/polyacrylic acid complex(CLGO/PAA) was formed by esterification reaction between 1,4-butanediol and carboxylic acid of PAA at same time. The CLGO/PAA aerogel was prepared by freeze drying method. The CLGO/PAA aerogel has good stability and high saturated adsorption capacity for the adsorption of Pb(II) ions in water. The structure and properties of the CLGO/PAA aerogel were characterized by using x-ray diffractometry(XRD), field emission scanning electron microscopy (FESEM), infrared spectroscopy(FT-IR), and atomic absorption spectrometer(AAS), respectively. The results show that the prepared CLGO/PAA aerogel possess elliptical pore structure. In addition, the adsorption properties of the CLGO/PAA aerogel for Pb(II) in water were studied under different pH, different concentrations of Pb(II), contact time and number of adsorbent cycles. The results show that the adsorption amount of Pb(II) could reach to 640 mg g−1 at the initial concentration of Pb(II) was 500 mg l−1, and the adsorption equilibrium could be reached after 60 min. The adsorption amount for Pb(II) was still 143 mg g−1 after 5 times cycle.

Preparation of cyclodextrin-modified graphene oxide and its adsorption properties for Pb (II)

In this paper, the improved Hummers method was used to prepare graphene oxide (GO) and modified by cyclodextrin to prepare cyclodextrin-modified graphene oxide (CDGO) composites. The composites were characterized by Fourier transform infrared spectroscopy (FTIR) and X-ray powder diffraction (XRD). The adsorption properties of GO and CDGO for Pb2+ were measured by atomic absorption spectrophotometer. The results showed that the number of functional groups of the modified material and the adsorption sites increased. The adsorption capacities of GO and CDGO for lead were respectively 86.47mg/g and 165.52mg/g, which were consistent with the quasi-secondary kinetic model and Langmuir isotherm adsorption model. CDGO showed better adsorption capacity.

Preparation of Al-doped xonotlite and its adsorption properties for Pb(II) in wastewater

Preparation of Al-doped xonotlite and its adsorption properties for Pb(II) in wastewater

Synthesis and characterization of mesoporous polymeric microspheres of methacrylic derivatives of aromatic thiols

The paper presents the synthesis and characterization of mesoporous microspheres of derivatives of three aromatic thiols: S-phenyl 2-methylprop-2-enethioate (PSM), S,S′-thiodi-4,1-phenylenebis(thiomethacrylate) (DMSPS), and bis[4(2-hydroxy-3-methacryloyloxypropoxy)phenyl]sulfide (BES.DM) with divinylbenzene (DVB). The microspheres were obtained by the emulsion-suspension polymerization procedure. The chemical and porous structure, morphology, and properties of the microspheres were analyzed by attenuated total reflection-Fourier transform infrared (ATR/FT-IR) spectroscopy, low-temperature nitrogen adsorption data, optical microscope MORPHOLOGI G3, differential scanning calorimetry (DSC), and wavelength dispersive X-ray fluorescence (WD-XRF). Moreover, studies on the Pb(II) ions sorption process were carried out on the above mentioned compounds. The sorption kinetics and mechanism were described by the pseudo-first order, pseudo-second order, and intraparticle diffusion models. The sorption equilibria were described by the Langmuir and Freundlich isotherms. The PSM-DVB, DMSPS-DVB, and BES.DM-DVB microspheres exhibit high thermal resistance and good adsorption properties of Pb(II) ions. The best adsorption properties for the examined microspheres were obtained at pH 5. The highest monolayer adsorption capacity determined by Langmuir isotherm was obtained for the DMSPS-DVB microspheres and was equal to 22.54 mg/g. The preliminary studies show that the synthesized microspheres can be used as heavy metal ion sorbents from aqueous solutions.

Magnetic graphene oxide grafted with different hydrophobic chain lengths low‐generation polyamidoamine dendrimers for adsorption of Pb(II) and Hg(II) in aqueous solution

In this study, using hexamethylenediamine (HMD)‐modified magnetic graphene oxide (HMGO‐NH2) as carrier, HMD and methyl acrylate as function monomers, MGO grafted with longer hydrophobic chain length low‐generation HMD type polyamidoamine dendrimers (HMGO‐PAMAM‐G1.0) was prepared by Michael addition and amidation condensation reaction. The obtained HMGO‐PAMAM‐G1.0 sample was characterized by transmission electron microscope, X‐ray diffraction, Fourier transform infrared spectroscopy, nitrogen adsorption/desorption isotherms, thermal properties analysis, vibrating sample magnetometer, and X‐ray photoelectron spectroscopy analysis. The adsorption properties for Pb(II) and Hg(II) heavy metal ions of HMGO‐PAMAM‐G1.0 and the magnetic graphene oxide grafted with shorter hydrophobic chain length low‐generation ethylenediamine type polyamidoamine dendrimers (MGO‐PAMAM‐G1.0) reported in our previous work were explored. The results showed that the HMGO‐PAMAM‐G1.0 with longer hydrophobic chain length had higher adsorption capacity for Pb(II) and Hg(II) than MGO‐PAMAM‐G1.0 at the higher concentrations. The adsorption process of HMGO‐PAMAM‐G1.0 and MGO‐PAMAM‐G1.0 for Pb(II) and Hg(II) was well in agreement with pseudo‐second‐order kinetic model and the Langmuir isotherm model. The Pb(II) was only adsorbed on the sample, while the Hg(II) was partially reduced to Hg(I) in the adsorption process. POLYM. COMPOS., 40:E1685–E1696, 2019. © 2018 Society of Plastics Engineers

Adsorption Properties of Pb2+ by Amino Group’s Functionalized Montmorillonite from Aqueous Solutions

The remediation of wastewater containing Pb2+ has attracted much attention due to the harm of Pb2+ to the environment and human health. A promising adsorbent, functionalized montmorillonite modified with a ligand diethylenetriamine (DETA) was prepared under mild reaction conditions. The modified montmorillonite (DETA-MMT) and nature montmorillonite (Na-MMT) were then characterized with the help of XRD, FTIR, TG/DTG, and BET. It was revealed that the modifier DETA was successfully inserted into interlayers of montmorillonite, as demonstrated by the characterizations. Batch adsorption experiments of Pb2+ onto Na-MMT and DETA-MMT in solutions were studied as a function of various parameters, such as pH, contact time, initial concentration, and temperature. The maximum adsorption capacity of DETA-MMT was 61.1 mg g–1, which had more than doubled compared with that of Na-MMT. The adsorption thermodynamics of Pb2+ by DETA-MMT was studied, and it showed a endothermic process. The adsorption kinetics of two sample...

Enhanced Selective Adsorption of Pb(II) from Aqueous Solutions by One-Pot Synthesis of Xanthate-Modified Chitosan Sponge: Behaviors and Mechanisms

Sponge-like xanthate-modified chitosan with a three-dimensional network macroporous structure was prepared using a facile one-pot approach. The as-prepared adsorbent possessed remarkable adsorption capacity and excellent mechanical property as well as rapid and intact separation performance. Adsorption properties of Pb(II), Cd(II), Ni(II), and Zn(II) on xanthate-modified chitosan sponge (XCTS) were systematically investigated in single and multiple systems. The experimental data for each heavy metal adsorption well fitted to the pseudo-second-order kinetic model and Langmuir isotherm model. The maximum adsorption capacities of Pb(II), Cd(II), Ni(II), and Zn(II) were 216.45, 92.85, 45.46, and 41.88 mg/g, respectively. The mutual interference effects of heavy metals in multiple systems were investigated using the inhibitory effect and equilibrium adsorption capacity ratios. The results indicated that the coexisting metal ions had a synergistic promoting effect on Pb(II) adsorption. The competitive adsorptio...

대나무 활성탄의 산 개질이 납과 구리 이온의 흡착에 미치는 영향

Effects of acid (HNO3 and HCl) modification on the adsorption properties of Pb(Ⅱ) and Cu(Ⅱ) onto bamboo-based activated carbon (BAC) were investigated through a series of batch experiments. The carbon content increased and oxygen content decreased with acid treatment. HNO3 induced carboxylic acids and hydroxyl functional groups while HCl added no functional group onto BAC. The pseudo-second order model better described the kinetics of Pb(Ⅱ) and Cu(Ⅱ) adsorption onto experimented adsorbents, indicating that the rate-limiting step of the heavy metal sorption is chemical sorption involving valency forces through sharing or exchange of electrons between the adsorbate and the adsorbent. The equilibrium sorption data followed both Langmuir and Freundlich isotherm models. The adsorption capacities of BAC were affected by the surface functional groups added by acid modification. The adsorption capacities were enhanced up to 36.0% and 27.3% for Pb(Ⅱ) and Cu(Ⅱ), respectively by the HNO3 modification, however, negligibly affected by HCl.

Nanosized yolk–shell Fe3O4@Zr(OH)x spheres for efficient removal of Pb(II) from aqueous solution

In this work, Fe3O4@Zr(OH)x yolk–shell nanospheres (YSNs) were synthesized via a two-step process and further examined as adsorbents for the removal of Pb(II). To understand the hollow structure on the adsorption properties of Pb(II), another adsorbent without hollow cavities, i.e., Fe3O4@SiO2@Zr(OH)x core–shell nanospheres (CSNs), was also prepared for comparison. The adsorption results showed that Fe3O4@Zr(OH)x YSNs exhibited 41.6% higher Pb(II) adsorption capacity as compared to that of Fe3O4@SiO2@Zr(OH)x CSNs. The isotherm was well fitted to Langmuir adsorption model with qmax value of 310.8mg/g after normalized by the weight of Zr in Fe3O4@Zr(OH)x YSNs. Scanning transmission electron microscopy (STEM) mapping results revealed that the existence of cavities between Fe3O4 cores and Zr(OH)x shells is responsible for the improved adsorption performance. XPS analysis indicated the surface hydroxyl groups played a key role in the Pb(II) adsorption. The removal efficiency of Pb(II) was maintained above 90% in five consecutive adsorption–desorption cycles.

Comparative Study on Adsorption of Pb(II) Ions by Alginate Beads and Mangrove-Alginate Composite Beads

The aim of the present study report on the adsorption performance of alginate bead (AB) and mangrove-alginate composite bead (MACB) bead adsorbents for the removal of Pb(II) ions from aqueous solution. The effects of pH and initial concentration with contact time on the adsorption properties of Pb(II) onto both adsorbent were investigated and were described by isotherm and kinetic studies. The isotherm adsorption data were fitted well to Freundlich isotherms for both beads and the maximum adsorption capacities of the AB and MACB beads were 29.02 mg g-1 and 10.84 mg g-1, respectively. The kinetics adsorption data were best described to a pseudo-second-order kinetic models showing that the MACB beads had a higher kinetic adsorption rate at 2.6084 g mg-1 min-1 compared to AB at 0.7043 g mg-1 min-1.

Removal of Pb(II) ion from aqueous solution by graphene oxide and functionalized graphene oxide-thiol: effect of cysteamine concentration on the bonding constant

Efficient adsorbent graphene oxide (GO) and its derivative, i.e., thiol-functionalized graphene oxide (GO-SH), was used for the removal of noxious Pb(II) ion from the aqueous phase. Different amounts, i.e., 60, 80, and 100 mg of cysteamine, were used as functionalizing agent to functionalize the GO with thiol group; hence, three different nanocomposites, i.e., GO-SH1, GO-SH2, and GO-SH3 were prepared from the different amount of the cysteamine. The developed nanocomposites were characterized using various analytical techniques such as Fourier transform infrared spectroscopy, scanning electron microscopy, and X-ray diffraction analysis. The whole removal and adsorption process was well illustrated and investigated. The impact of influential factors including initial concentration, pH, contact time, temperature, and concentrations cysteamine on the adsorption properties of Pb(II) from aqueous solution was well elucidated and optimized. The obtained equilibrium results were inserted in various adsorption isotherm models such as Langmuir (liner types I, II, III, and IV), Freundlich, Temkin, Helsey, and Dubinin-Radushkevich isotherms, it was found that the Langmuir (type I) model demonstrated was well fitted and in good agreement with the maximum adsorption of Pb(II) ion from aqueous solution. Thermodynamic functions, such as ∆G°, ∆H°, and ∆S° were calculated and it reveals that the adsorption of Pb(II) ion on all the surfaces was spontaneous and endothermic in nature.

Convenient Synthesis of Micron-sized Macro Porous Polymers with Silica on their Surfaces and Excellent Adsorption Performance for Pb(II) Ion

The phenol-formaldehyde/silicon dioxide resin (PFSR) adsorbent showed superior adsorption properties for Pb (II) ion. The aimed composite material was characterized by XRD, FT-IR, SEM and BET techniques. Sorption properties of the synthesized composite powder were evaluated through sorption of lead ions from their aqueous solutions. Batch sorption tests were carried out at different initial heavy metal ion concentrations revealing that the synthesized composite has great selectivity to lead ions. The experimentally obtained sorption results were analyzed using pseudofirst and second order kinetic models to stand on the possible sorption mechanisms indicating the sorption behavior of the studied ions onto PFSR composite belonged to the pseudo-second order kinetic model and the sorption process was a chemical process. Isotherm plots were constructed and analyzed using Langmuir, Freundlich, Temkin, D-R and Jovanoic isotherm models. The D-R and Temkin isotherm model provided the best fit for the Pb(II) ion, revealing the maximum adsorption capacity of 13.74 mg/g. Thermodynamic studies revealed that Pb(II) adsorption on the PFSR adsorbent is a favorable, spontaneous, and endothermic process.

Chemical modification of silica gel with multidentate ligands for heavy metals removal

Two kinds of silica-gel supported chelating adsorbents with different multidentate ligands were synthesized for heavy metals removal. The obtained adsorbents were named as SG-AD and SG-ASD. SG-AD was the silica-gel supported dithiocarbamate ligand adsorbent; SG-ASD was the silica gel-supported dithiocarbamate and Schiff’s bases adsorbent. FT-IR analysis and thermogravimetry analysis were used to characterize the prepared adsorbents. Their adsorption properties of Pb(II), Hg(II), Cu(II), Zn(II), and Cd(II) were also investigated. The results showed that SG-AD and SG-ASD showed high performance toward Pb(II) and Hg(II) removal, especially toward Hg(II) removal. Adsorption kinetics suggested that the adsorption processes of Pb(II) and Hg(II) on SG-AD and SG-ASD were governed by film diffusion and followed a pseudo-second-order model. The Langmuir model and Scatchard model were applied to fit the experimental equilibrium data for SG-AD and SG-ASD. With increasing temperature, the adsorption capacities and affinity constants of SG-AD and SG-ASD for Pb(II) and Hg(II) were increased. SG-ASD which contained two kinds of multidentate ligands showed strong chelating affinity to Hg(II). Langmuir model and Scatchard model can be integrated in describing the processes of heavy metal adsorption.

Synthesis and adsorption properties of Chitosan cross linked with phenol - formaldehyde resin for the removal of heavy metals and dyes from water

A novel activated carbon material has been prepared by carbonization and activation of Phenol- Chitosan-Formaldehyde resin (PCFR) which synthesized by the condensation polymerization method. The physicochemical properties of the PCFR were characterized by SEM, XRD, BET, EDS, TGA and FTIR spectroscopy. The adsorption properties of Pb(II) ion and Methylene blue (MB) onto PCFR were investigated by batch techniques. The particle size of adsorbent was 65-70µ. Kinetic studies indicated that Pb(II) ion and MB adsorption followed the pseudo-second-order model. The adsorption may be controlled by external mass transfer followed by intra-particle diffusion mass transfer. Equilibrium adsorption was investigated by the Langmuir, Freundlich, Temkin, D-R and Jovanoic isotherms. The thermodynamics parameters of adsorption