Removal Of Lead Ions Research Articles

Improving household water treatment: using zeolite to remove lead, fluoride and arsenic following optimized turbidity reduction in slow sand filtration

Despite the United Nations 2030 agenda, large number of both urban and rural dwellers in low-income countries continue to lack access to improved water. Thus, increased effort is required towards enhancing low-cost drinking water treatment technologies especially for developing countries. Slow sand filter (SSF) is one of the most commonly used low-cost and efficient technologies for treating household drinking water. However, effectiveness of SSF is substantially affected by very high turbidity and relatively large amounts of dissolved heavy metals. To enhance removal of both turbidity and heavy metals, this study optimized sand bed depth (SBD) of SSF and investigated the potential of natural zeolite from Uganda for removal of lead, arsenite (As(III)) and fluoride ions from water. To remove lead ions, the zeolite was used in its natural form. However, to remove As(III) and fluoride, the natural zeolite was modified using hexadecyltrimethylammonium bromide solution. Removal of high turbidity was found to require a large optimal SBD. Furthermore, efficiency of treating synthetic turbid water increased with increasing initial turbidity. Variation of final turbidity with SBD was found to be best described by an exponential function. Optimal SBDs on top of an underdrain gravel layer of 0.2 m were 453, 522, 561, and 580 mm for turbidity of 60, 80, 100, and 120 NTU, respectively. Optimized SBD used achieve at least 95% efficiency in removing suspended particles from water with turbidity 120 NTU was found to save up to 35% of the total cost for acquiring sand volume required by a conventional SSF. For a particular zeolite mass, removal efficiencies of lead, As(III) and fluoride generally increased with increasing contact time. Removal efficiencies of lead, As(III), and fluorides were also shown to increase with increasing zeolite mass. Lead removal efficiencies using natural zeolite were 75 and 98% under 20 and 40 min, respectively. Removal of As(III) using modified zeolite mass was 91% within contact time of 10 min. Adsorption of fluoride on modified zeolite was 80% within 5 min. Adsorption of lead, As(III), and fluorides indicated promising potential of natural zeolites from Uganda for treating polluted water.

Casein-copper hybrid nanoflowers: application in lead (II) and cadmium (II) ions removal from aqueous medium

ABSTRACT In this study, eco-friendly casein-copper hybrid nanoflowers (CAS-Cu HNFs) were synthesised and their applicability for the removal of Pb(II) and Cd(II) ions was investigated. Hybrid nanoflowers were synthesised by adding CuSO4 solution on casein in PBS medium. According to the evaluation of SEM images, regular nanoflower structures were obtained after the addition of 40 µL of 100 mM CuSO4 and 12 h incubation. Characterisation studies were performed by XRD, SEM-EDX, FTIR and TGA. The effects of contact time, pH, temperature and heavy metal ion concentration on the adsorption performance were investigated. Optimum adsorption was achieved at 60 min contact time and 35 and 30 °C for Pb(II) and Cd(II) ions, respectively. The performance of CAS-Cu HNFs was evaluated by linear and non-linear forms of adsorption isotherms and adsorption kinetics, respectively. The linear Langmuir isotherm model showed compatibility and the maximum adsorption capacity was found to be 769.23 and 156.25 mg/g for Pb(II) and Cd(II) ions, respectively. CAS-Cu HNFs has great potential as an eco-friendly, nanoscale, flower-like, organic–inorganic hybrid nano-flower adsorbent for the effective removal of Pb(II) and Cd(II) ions from aqueous solutions.

Preparation and Evaluation of Phenol Formaldehyde-Montmorillonite and Its Utilization in the Adsorption of Lead Ions from Aqueous Solution.

In this study, phenol formaldehyde-montmorillonite (PF-MMT) was prepared and used for lead ion (Pb2+) adsorption. Batch adsorption experiments were conducted to determine the optimal conditions. The calculated adsorption equilibrium (q) revealed that pseudo-second-order (PSO) and Langmuir isotherm models best fit the experimental data, suggesting chemisorption as the main mechanism. An adsorption capacity (qmax) of 243.9 mg/g was achieved. Fourier transform infrared (FTIR) analysis showed new peaks in PF-MMT-Pb, indicating metal complexation. Scanning electron microscopy (SEM) imaging displayed distinct Pb2+ clusters on the adsorbent surface. Adsorption was rapid, attaining equilibrium within 90 min. Effects of time, dose, concentration, and pH were systematically investigated to optimize the process. Lead ion removal efficiency reached 98.33% under optimum conditions after 90 min. The adsorption process was chemisorption based on the Dubinin-Kaganer-Radushkevich model with a free energy of 14,850 J/mol. The substantial adsorption capacity, rapid kinetics, and high removal efficiency highlight PF-MMT's potential for effective Pb2+ removal from aqueous solution.

Development of MXene for removal of lead (Pb+) ions from wastewater

Abstract A new family of 2D materials with enhanced properties than graphene plays a crucial role in environmental remediation and sustainability. The concentration of heavy metal ions in wastewater is an emerging issue in the global scenario. Heavy metals such as lead, chromium, cadmium, etc. are natural carcinogens and adversely affect environmental species, which tend to have potential activities on the surface of the new families. Lead poisoning is a very raising issue in some parts of India and is a major effluent disposed of to the waterbodies from various industrial streams. The removal of the lead components is studied in this research using adsorption experimentation using MXene as the surface-active adsorbent. The possible mechanism for lead removal from wastewater is also discussed, as well as the effective regeneration and reusability of the adsorbent over long adsorption cycles. MXenes were applied after the confirmation using X-ray diffraction, scanning electron microscopy, Fourier transform infrared spectroscopy and zeta-potential. The induced coupled plasma–optical emission spectroscopy confirms the lead remediation by over 96% in the first adsorption cycle, which was then reduced to over 92% in the second adsorption cycle. The lead contamination was under the permissible limits as per the water standards.

Removal of lead ions (Pb2+) from aqueous solution using chitosan/starch composite material: Experimental and density functional theory findings

AbstractTreatment of wastewater has become vital to prevent environmental pollution in recent years. Adsorption is an easily applicable, low-cost and efficient method and is the subject of this study. In this study, an adsorbent was synthesized to be used in heavy metal removal using chitosan and starch. The composite was characterized by Fourier transform infrared (FTIR) spectrophotometry, X-ray powder diffraction (XRD), thermogravimetric analysis (TGA), and scanning electron microscopy (SEM), energy-dispersive X-ray (EDX) analysis. It was determined that the composite had an amorphous and compact structure. Adsorption experiments were carried out under the optimized parameters such as solution pH, concentration, adsorbent amount, equilibrium time, and temperature. It shows that during adsorption, with the increase in pH, the adsorption efficiency and adsorption capacity first increase and then a fluctuation occurs. The highest adsorption efficiency and Q value were reached at pH 3.46 as 78% and 0.038 mol/kg, respectively. Moreover, the adsorption capacity (Q) reached its highest value with a value of 0.067 mol/kg in the presence of 30 mg adsorbent. Equilibrium experiments were validated by the Langmuir, Freundlich, Temkin and Dubinin–Radushkevich isotherm models. To investigate the adsorption mechanism, pseudo-first-order (PFO) and pseudo-second-order (PSO) kinetic models were used. It was determined that the adsorption process followed the D-R isotherm (R2 = 0.99) and PSO (R2 = 0.99). Therefore, the existence of chemical adsorption can be mentioned. Thermodynamic parameters enthalpy (∆H), Gibbs free energy (∆G) and entropy change (∆S) were investigated. The adsorbate-adsorbent interactions were studied by density functional theory (DFT).

Influence of terephthalate anion in ZnAl layered double hydroxide on lead ion removal: Adsorption, kinetics, thermodynamics and mechanism

In this work, layered double hydroxides (LDHs) intercalated with carbonate (ZnAl-CO3) and terephthalate (ZnAl-TA) anions were synthesized for the removal of lead (Pb2+) ions from aqueous solutions. ZnAl-TA showed better Pb2+ removal performance than ZnAl-CO3. In the kinetic study, the Elovich model obtained the best fit; the Weber-Morris model showed that intraparticle diffusion is not a limiting step in the process. The Sips model fitted better to the adsorption isotherms, with a maximum adsorption capacity of 124 mg.g−1. The thermodynamic study showed that the process is spontaneous and endothermic. In the regeneration of ZnAl-TA, the use of NaCl as a desorption eluent showed less Zn2+ leaching and greater desorption efficiency compared to acid eluents. The adsorption capacity of Pb2+ in the presence of other ions followed the order Ni2+ > Ca2+ > Cd2+ > Mg2+ > Cu2+. The ZnAl-TA adsorbent reached 88% of its initial efficiency after 3 cycles with high stability. From post-adsorption XRD, FTIR, and XPS analyses, Pb2+ was removed predominantly by chelation, surface complexation, and precipitation. In general, the ZnAl-TA adsorbent proved to be an efficient sorbent material for Pb2+ removal from aqueous effluent.

Hagenia abyssinica-Biomediated Synthesis of a Magnetic Fe3O4/NiO Nanoadsorbent for Adsorption of Lead from Wastewater.

Magnetic nanocomposite adsorbents are cost-effective, environmentally friendly, easy to use, and highly efficient at removing metals from large volumes of wastewater in a short time by using an external magnetic field. In this study, an Fe3O4/NiO composite nanoadsorbent was prepared by varying the mass percent ratios of NiO (50, 40, 30, 20%), which are denoted Fe3O4/50%NiO, Fe3O4/40%NiO, Fe3O4/30%NiO, and Fe3O4/20%NiO, respectively, using Hagenia abyssinica plant extract as the template/capping agent and a simple mechanical grinding technique. The nanocomposites were characterized using an X-ray diffractometer (XRD), scanning electron microscopy (SEM), Fourier transform infrared (FT-IR) spectroscopy, nitrogen adsorption, and ζ-potential measurements. The adsorption performance of the nanoadsorbent was assessed for the removal of lead (Pb2+) ions from aqueous solutions. Among the composite adsorbents, Fe3O4/50%NiO demonstrated the best Pb(II) removal efficiency (96.65%) from aqueous solutions within 80 min at pH 8, at a 100 mg/L lead concentration and 0.09 g of adsorbent dose. However, with the same parameter, only 62.8% of Pb(II) was removed using Fe3O4 nanoparticles (NPs). The adsorptive performance indicated that the optimum amount of porous material (NiO) in the preparation of the Fe3O4/NiO composite nanoadsorbent, with the aid of H. abyssinica plant extract, enhances the removal of toxic heavy metals from aqueous solutions. Multiple isotherm and kinetic models were used to analyze the equilibrium data. Adsorption isotherm and kinetic studies were found to follow the Freundlich isotherm and pseudo-second-order kinetics, respectively.

Heavy metal decontamination by ion exchange polymers for water purification: counterintuitive cation removal by an anion exchange polymer

Ion exchange polymers were used for mercury and lead ions removal in water. The heavy metal ion concentration was analyzed by two independent methods: inductively coupled plasma–optical emission spectroscopy (ICP-OES) and gravimetry. The studied cation exchange polymer (CEP) was sulfonated poly(ether ether ketone) (SPEEK), and the anion exchange polymer (AEP) was poly(sulfone trimethylammonium) chloride (PSU-TMA). The removal capacity was connected with the ion exchange capacity (IEC) equal to 1.6 meq/g for both polymers. The concentration ranges were 0.15–0.006 mM for Hg2+ and 10.8–1.0 mM for Pb2+. SPEEK achieved 100% removal efficiency for mercury and lead if the concentration was below the maximum sorption capacity (Qmax), which was about 210 mg/g for Pb2+ with SPEEK. For PSU-TMA, the surprising removal efficiency of 100% for Hg2+, which seemed incompatible with ion exchange, was related to the formation of very stable complex anions that can be sorbed by an AEP. Langmuir adsorption theory was applied for the thermodynamic description of lead removal by SPEEK. A second-order law was effective to describe the kinetics of the process.

Polyrhodanine-Functionalized Magnetic-Activated Carbon for Efficient Removal of Lead Ions and Malachite Green From Wastewater

The development of wastewater treatment agents with high treatment capacity and efficient separation is crucial for the remediation of heavy metal ions and organic dye wastewater. In this study, a polyrhodanine functional magnetic-activated carbon composite (PR-mAC) was synthesized via a one-step co-precipitation method combined with chemical oxidation polymerization. As an innovative water treatment agent, PR-mAC possesses not only environmentally friendly and easily obtainable raw materials but also magnetic properties that facilitate its reusability. Notably, PR-mAC exhibited remarkable removal efficiency towards lead ion (Pb(II)) and malachite green (MG). Experimental results demonstrated that the adsorption of Pb(II) and MG followed quasi-second-order kinetic model, while the Hill isothermal adsorption model and Redlich–Peterson isothermal adsorption model were suitable for Pb(II) and MG removal, respectively. All adsorption processes were spontaneous endothermic reactions. The maximum adsorption capacities reached 223.71 mg/g and 315.46mg/g, respectively. Even after undergoing 5 cycles, the material maintained satisfactory removal performance for Pb(II) and MG pollutants. Therefore, the prepared PR-mAC represents an optimal agent for wastewater treatment due to its effective capability in removing both metal ions and dyes.

Effect of SH/SBA‐15 Molar Ratio on Pb(II) and Cd(II) Ions Adsorption from Aqueous Solution by Mercaptopropyl‐grafted SBA‐15 Mesoporous Material as Adsorbent

AbstractThe purposes of the current study were to investigate the adsorption of Pb(II) and Cd(II) from aqueous solution by thiol‐functionalized SBA‐15 materials designed by SBA‐15‐SH (x) where x is the SH/SBA‐15 molar ratio, which corresponds to the introduced moles number of Mercapto moieties to that of siliceous of the SBA‐15 materials. Furthermore, these materials were synthesized using 3‐Mercaptopropyltrimethoxysilane (MPTMS) via post‐grafting approach. SBA‐15‐SH(x) materials were characterized by XRD, N2 adsorption‐desorption and FT‐IR. The incorporation of SH fragments was proved by FT‐IR Spectroscopy, thermogravimetric analysis (TGA) and solid state 13C and 29Si NMR Spectroscopy.The removal of lead ions is more important than that of cadmium ions. Furthermore, the lead removal on SBA‐15‐SH(x) increased with the increase of SH/SBA‐15 molar ratio (removal rate of 28.5, 71.3, and 96.8 % for SH/SBA‐15 molar ratio=0.35, 0.7 and 1.4, respectively) while the removal of cadmium was not affected (around 57 % removal rate for all molar ratios).

Shape-memory cellulose nanofiber/polyglutamic acid-based aerogels as novel adsorbents for the removal of heavy metals from aqueous solutions

Water bodies contaminated by heavy metals pose a severe threat to human health and the eco-system. The synthesis of eco-friendly adsorbents is essential to eliminate the use of toxic chemicals to eradicate heavy metal pollution from water bodies. In this study, a novel aerogel was prepared using a simple one-pot reaction between cellulose nanofibers and polyglutamic acid through a crosslinking reaction for the removal of lead, zinc, and copper ions from aqueous solutions. Surface analysis revealed that the aerogel consisted of abundant carboxyl and amino functional groups. The optimal pH of the solution for the adsorption of lead, zinc, and copper was 4, 5, and 5 respectively. The experimental data revealed that the adsorption followed pseudo-second-order kinetics at 22 °C for all the heavy metals. The adsorption behaviour of zinc and copper could be described through the Langmuir isotherm model whereas, the adsorption behaviour of lead was described by the Freundlich isotherm model. The maximum experimental adsorption capacity was 101.81, 59.26, 100.59 mg/g for lead, zinc, and copper respectively. The adsorption mechanisms involved were coordination bonding and electrostatic attraction. The high adsorption capacity, ease of separability and good mechanical strength deems these aerogels suitable for the adsorption of heavy metals from water.

Adsorptive Removal of Selected Toxic Metals from Pharmaceutical Wastewater using Fe<sup>3</sup>O<sup>4</sup>/ZnO Nanocomposite

Pharmaceutical wastewater is a major source of environmental contamination, often containing toxic metals that pose significant threats to ecosystems and public health. This study explores the potential of magnetite/zinc oxide (Fe3O4/ZnO) nanocomposites prepared using a sol-gel method for the removal of lead, cadmium, and copper ions from pharmaceutical wastewater. The nanocomposite was characterized using X-ray diffraction (XRD), High-resolution scanning electron microscopy (HRSEM)/energy dispersive spectroscopy (EDS) and Fourier transmission infrared spectroscopy (FTIR). The XRD analysis of the nanocomposite identified 2θ (theta), of 31.7º, 34.4º, 36.2º, 47.5º, 56.6º, 62.8º, 66.3º, and 67.9º which correspond to the crystal planes of (100), (002), (101), (102), (110), (103), (200), and (112), respectively. The diffraction peaks associated with Fe3O4 at 2θ of 18.02º, 29.4º, and 43.3º, related to the crystal planes of (111), (220), and (400), respectively of the Fe3O4 phase. The HRSEM image of the nanocomposite exhibited spherical-shaped structures of Fe3O4/ZnO, and some irregular shapes. The effects of the contact time, dosage and temperature on the removal percentage of toxic metal ions were studied. Freundlich and Langmuir isotherm constants and correlation coefficients were determined and the equilibrium process was better described by the Langmuir isotherm. The adsorption process followed a second order kinetics and the thermodynamic parameters showed that the involved process was spontaneous. These findings contribute to the advancement of environmentally friendly technologies for the pharmaceutical industry and the broader field of wastewater remediation.

Effect of process parameters on the synthesis and lead ions removal performance of novel porous hydroxyapatite sheets prepared via non-aqueous precipitation method

Herein, porous hydroxyapatite sheets with high lead ions removal performance are synthesized via self-assembly non-aqueous precipitation method, and the effects of process parameters on the synthesis and lead ions removal performance are systematically investigated. The optimized precursors concentration, the molar ratio of calcium to phosphorus and the calcination temperature are 0.25 mol/L, 1.67 and 650 °C, respectively. The refinement XRD, FE-SEM and EDS tests of the optimized samples show that the samples have a porous sheet structure with uniform pore size and wall thickness. The lead ions removal rate of hydroxyapatite sheets has the maximum value of 99.6% when the hydroxyapatite addition amount is 1 g/L. The lead ions removal content is the maximum of 1303.6 mg/g when the initial lead ions concentration is 9 mmol/L. The removal mechanism of lead ions by porous hydroxyapatite sheets prepared in this work is the composite mechanisms of surface adsorption, surface complexation and ions exchange. The hydroxyapatite porous sheet material prepared by optimizing the process parameters in this study has the advantages of high removal capacity and wide adaptability, so it is expected to become a novel adsorbent to solve lead-containing wastewater.

Modified Adsorbents Based on Glycidyl Methacrylate Copolymers for the Removal of Copper and Lead Ions from Wastewater

Modified Adsorbents Based on Glycidyl Methacrylate Copolymers for the Removal of Copper and Lead Ions from Wastewater

Removal of Lead Ion (Pb2+) in Water Using Modified Clay-Carbon-Manganese Monolith: Characterization and Adsorption Studies

Removal of Lead Ion (Pb2+) in Water Using Modified Clay-Carbon-Manganese Monolith: Characterization and Adsorption Studies

“Comparative study of Graphene Oxide sand Composite (GOSC) and Graphene Coated iron Oxide (GCIO), for Pb2+ ion removal”

Lead is a heavy metal that affects all systems of the human body. An adsorption method was used for removal of lead from wastewater. For this purpose, two adsorbents, graphene oxide coated sand particles (GOSC) and graphene coated iron oxide (GCIO) were prepared by coating of graphene sheets on the surfaces of sand particles and iron oxide using sucrose solution under controlled heating program. Both adsorbents offered very fast removal of Pb+2 ions with small amount of GOSC and GCIO, respectively. Characterization of GOSC was done using several advanced techniques like FTIR, XRD, SEM, EDX and TEM before and after adsorption of lead ions (Pb2+). Various parameters such as the effect of time, pH, adsorbent, dose effect, concentration and temperature were studied for both adsorbents. Various adsorption and kinetic models were also examined using adsorption data for both the adsorbents and results showed that removal of lead (Pb2+) ions through GOSC follow Langmuir isotherm (R2 = 99%), second order kinetics (R2 = 98%) and higher intraparticle diffusion (R2 = 98%), respectively while in case of GCIO adsorbent, the removal of lead (Pb2+) ions follows Freundlich model (R2 = 99%), second order kinetics (R2 = 98%) and higher intraparticle diffusion (R2 = 98%).

Removal of lead from aqueous solution using Dead Sea mud

This study aimed to investigate the performance of the (DSM) as an adsorbent for removing of lead from aqueous solution. Batch adsorption experiments were conducted using dried and burned (DSM) at different temperatures. The impact of the main parameters that affect the adsorption process; namely the pH, contact time, initial lead concentration, dose of (DSM), solution temperature and the burning temperature of the (DSM) were investigated.The result revealed that 100 % removal of lead ions was achieved at pH 7, room temperature, a dose of 2g of dried (DSM) with a mixing speed of 15 rpm, for 3 h contact time and initial concentration of lead in the solution of 100 mg/l. The adsorption capacity reached: 39.84 mg/g, 39.74 mg/g, 39.1 mg/g, 39.12 mg/g, and 34.45 mg/g for dry samples, and burned samples at 200, 500, 800, and 1000 °C respectively. Kinetic models showed that the pseudo-second-order kinetic model was better (R2 = 0.99) than the othere used models to describe the adsorption process.Regarding the isothermal models, it was found that the D-R is the best fit for lead adsorption, with (R2) of 0.90 indicating physicochemical adsorption mechanism. Thermodynamic studies found that at the adsorption process occurs spontaneously and is exothermic in nature with ΔHo value of −49.419 kJ mol− 1 and ΔSo = −13.558 kJ mol− 1 and ΔGo value at 25 °C = −45.31KJmol-1. It can be concluded that high removal efficiency of (Pb+2) can be achieved by using (DSM) as adsorbent which considered as a low cost, naturally existing material.

Corn cob biochar for the removal of lead ions (II): simultaneous optimization of four response variables

Corn cob biochar for the removal of lead ions (II): simultaneous optimization of four response variables

An efficient and template‐free synthesis of mesoporous silica from coal fly ash

AbstractIn the study, the desilication liquids and acid‐leached residues derived from the “alumina extraction process” of coal fly ash (CFA) were used as raw materials to prepare sodium silicate precursor. Then, the mesoporous silica with controllable pore structure properties was synthesized by an efficient, template‐free process from obtained sodium silicate. The effect of the sodium silicate properties and synthesis conditions on the pore structure properties of disordered mesoporous silica were investigated. The resulting material was characterized by N2 adsorption–desorption, scanning electron microscopy (SEM), and transmission electron microscopy (TEM) and tested as an adsorbent for removal of lead ions (Pb2+). The results showed that the precursor with high modulus (3.0) and concentration (60 g·L−1) was beneficial for the synthesis of mesoporous silica with high specific surface area. The mesoporous silica with specific surface area of 690 m2·g−1 and pore volume of 1.28 cm3·g−1 was synthesized at mild aging temperature (40°C) and pH value of 8. Moreover, the materials possessed an adsorption capacity of 303 mg·g−1 for lead ions after amino modification. The adsorption efficiencies for lead ions were maintained at ~90% after five recovery cycles. Overall, the utilization efficiency of SiO2 in CFA reached up to 93%.

Surface decoration of polyethylene terephthalate (PET) waste bottle-derived ultrafiltration membrane for enhanced lead ion removal and antifouling properties

PET waste bottle can be potentially used to create eco-friendly ultrafiltration (UF) membranes for water and wastewater treatment. The surface modification and functionalization of PET UF membrane offer opportunities to further heighten the performance of the membrane. In this study, phase inversion technique was used to fabricate PET UF membranes and PET/graphene oxide (GO) nanocomposite membranes through a facile GO suspension coating approach. The GO nanosheets were deposited on the PET UF membrane as a wavy and wrinkly layer. Using lead (Pb) ions and bovine serum albumin (BSA) feed solutions, the filtration performances of the neat PET and GO-PET membranes were evaluated. It was observed that, the Pb ions and BSA removal efficiencies were greatly enhanced by the surface decorated GO. Compared to neat PET, the 0.5GO-PET membrane exhibited improved flux performance by 188% and 61% for the removal of Pb ions and BSA, respectively. A high Pb ion removal of 100% and a BSA rejection of 97% were achieved by 0.5GO-PET membrane. The lower fouling tendency of 0.5GO-PET membrane during long-term filtration was attributed to the increased surface hydrophilicity and smoothness upon the deposition of GO layer. This study demonstrates a sustainable solution for efficient water treatment and heavy metal removal.