Removal Of Pb Research Articles

Removal of Pb(II) ions from aqueous solutions using natural and HDTMA-modified bentonite and kaolin clays

This work focused on the removal of Pb(II) from aqueous solution using kaolin and bentonite clays modified with hexadecyl trimethyl ammonium bromide (HDTMA). The clays were characterized using a zetasizer, scanning electron microscopy (SEM), powder X-ray diffraction (PXRD), Brunauer-Emmet-Teller (BET), Fourier-transform infrared (FTIR) spectroscopy and thermal gravimetric analysis (TGA). Factors that influence the adsorption of Pb(II) from aqueous solution, namely pH, contact time, adsorbent mass, ionic strength, temperature and initial Pb(II) concentration were investigated. The results show that HDTMA was successfully incorporated into the kaolin and bentonite clay structures. The most favorable parameters for the adsorption of Pb(II) ions onto all adsorbents was pH of 6.0, temperature of 25 °C and adsorbent mass of 200 mg. Adsorption isotherms and kinetic studies showed that the adsorption of Pb(II) onto kaolin, bentonite and organobentonite clays followed the Langmuir isotherm and pseudo-first order kinetic model, while the adsorption onto organobentonite was better explained by the Freundlich isotherm and pseudo-second order kinetic model. Maximum monolayer adsorption capacity of organobentonite, calculated from the Langmuir model was 18.75 mg/g, which is higher than that obtained for the unmodified bentonite (14.71 mg/g); while for organokaolin it was 2.26 mg/g, which is less than that of the unmodified kaolin (4.19 mg/g). Thermodynamic studies showed that the reactions were exothermic and unfavoured at high temperatures. The adsorbents also showed good removal efficiency for up to four regeneration cycles.

Efficient removal of Pb(II) and Cd(II) from water by polyethyleneimine-amidated sepiolite-sodium alginate composite microspheres: Characterization and mechanistic analysis

In order to improve the physicochemical properties of heavy metal adsorbents, researchers developed a novel composite microsphere material (SEI) by incorporating Sepiolite (Sep) and cross-linked polyethyleneimine (PEI) with sodium alginate (SA) as a carrier. The stability of the SEI under normal use conditions was high by thermogravimetric analysis, and COOH, OH, and NH2 functional groups were detected by FTIR, which were confirmed to be involved in adsorption. It was found that the adsorption rate of SEI on Pb(II) and Cd(II) obeyed a pseudo-second-order kinetic model, while the adsorption pattern was closely related to the Langmuir equation. Notably, the maximum adsorption capacity of SEI for Pb(II) and Cd(II) was 1099.93 mg/g and 112.89 mg/g, respectively, at 30 °C. In addition, thermodynamic analyses showed that the adsorption process was spontaneous, with entropy increase along with heat absorption. After six adsorption and desorption cycles, the removal of Pb(II) and Cd(II) by SEI remained above 90 %. These findings suggest that SEI is a promising and environmentally friendly material for the removal of Pb(II) and Cd(II).

Deep removal of Sn, Pb, and Sb in refined indium by vacuum distillation

To deeply separate the azeotropic impurities from the refined indium, three novel processes of vacuum distillation by considering the variables of vacuum pressure, loading mass, distillation time, temperature, and the effective vacuum evaporation area are firstly presented. Thermodynamic calculations show that Pb, Sb and Sn can be separated from indium melt by vacuum distillation due to their great difference in saturated vapor pressure and separation coefficient. Experiments show that distillation at 800 ℃ for 7 h under a pressure of 10−3 Pa could achieve the Pb concentration of 0.004 ppm in indium melt by enlarging the evaporation area and small ratio of h1/h4. After 950 ℃ distillation, the concentrations of Sb and Sn in the condensing indium reduced respectively from 0.15 ppm to 0.009 ppm, and 8.1 ppm to 0.05 ppm. Multiple processes of vacuum distillation were used to achieve the 7 N purity of indium, with the removal ratio of over 99.5 %. Besides, it is found out that when the temperature dropped from 1075 ℃ to 780 ℃, the movement stroke of vapor atoms reduced from 509 mm to 209 mm.

Conversion of PET bottles into carbonaceous adsorbents for Pb(II) removal from aqueous solutions via KOH activation

In this study, we present a novel approach to repurpose waste Polyethylene terephthalate (PET), a prominent contributor to global plastic usage, for the synthesis of efficient adsorbents via facial pyrolysis. The as-synthesized adsorbents were applied for the removal of lead (Pb(II)) ions in aqueous solution. Controlled batch experiments at pH 5 with 0.075 g of adsorbent at room temperature (20 °C) were conducted to measure Pb(II) adsorption capacities (mg/g) and fitted on isotherm models (Langmuir, Freundlich, and Temkin) and kinetics models (Pseudo-First order, Pseudo-Second order, and Elovich). Thermodynamic experiments conducted at four different temperatures (293 K, 303 K, 313 K, and 323 K) provided enthalpy, entropy, and Gibbs free energy change parameters, explaining the Pb(II) adsorption behaviors on PET-based adsorbents. The activation process involving KOH, followed by carbonization, yielded adsorbents with exceptional surface areas, pore volumes, and elevated oxygen contents (up to 22.8 %). The best adsorbent exhibited superior performance, achieving a maximum adsorption capacity of 219.7 mg/g within a rapid equilibrium time of 15 min. The adsorption behavior adhered well to the Langmuir isotherm model (R2 = 0.999) and Pseudo-Second Order kinetics model (R2 = 0.999). Furthermore, C600K600 displayed outstanding reusability, with negligible efficiency reduction (<5 %) even after five consecutive cycles. These results underscore the successful conversion of PET waste into a low-cost and highly effective adsorbent, offering a promising solution for sustainable waste management.

Treatment of clay soil contaminated with lead by in-situ immobilization process using animal bones

In this work, the application of bone wastes –Cow Bone, Pig Bone, and Horse Bone for the treatment of Lead (Pb) in Clay Soil by in-situ immobilization process, was investigated. The bone wastes were carbonized at a temperature of 700 OC for five hours. The Cow Bone Ash (CBA), Pig Bone Ash (PBA), and Horse Bone Ash (HBA) obtained were characterized with X-Ray Fluorescence (XRF). The physicochemical analysis of the soil sample was also performed. Batch experiments were done to investigate the effects of amendment dosage, time, and pH on immobilization efficiency. The physicochemical characterization of the amendments showed that they contain principally calcium phosphate. The XRF revealed that CBA contains 49.25 % CaO and 42.406 % P2O5, PBA contains 46.6 % CaO and 40.488 % P2O5 and HBA contains 45.664 % CaO and 33.857 % P2O5. The batch immobilization experiment revealed that CBA performed better than other sorbents in the removal of Pb. The removal efficiency is in the order CBA &gt; PBA &gt; HBA. The maximum removal of Pb in 100 g of soil was 71.2 %. This investigation has shown that animal bones can successfully remediate lead by immobilization process in a Pb contaminated Clay soil.

Efficient Pb(II) removal from contaminated soils by recyclable, robust lignosulfonate/polyacrylamide double-network hydrogels embedded with Fe2O3 via one-pot synthesis

Soil heavy metal removal strategies are increasingly valued for effectively reducing contamination and preventing secondary pollution. In this work, a double network hydrogel (Fe2O3@LH), consisting of lignosulfonate (LS) and polyacrylamide with embedded Fe2O3 nanoparticles, was synthesized successfully via a one-pot method and subsequently applied to adsorb lead (Pb) from contaminated soil. Incorporating Fe2O3 into the hydrogel enhances the adsorption capacity of Fe2O3@LH for Pb(II). The Fe2O3@LH hydrogel demonstrates a maximum Pb(II) adsorption capacity of 143.11 mg g–1, with Pb(II) removal mechanisms involving electrostatic adsorption, cation exchange, precipitation reactions, and the formation of coordination complexes, achieving a 22.3 % maximum removal efficiency in soil cultivation experiments. Additionally, the application of Fe2O3@LH markedly reduces the concentrations of cadmium (Cd) and arsenic (As) in the soil, meanwhile enhances the levels of total nitrogen (TN), soil organic matter (SOM), and cation exchange capacity (CEC) by 23.1 %, 10.6 %, and 16.9 %, respectively. Following 90 days of continuous application in the soil, the recovery rate of Fe2O3@LH remains above 75 %. The toxicity assay using zebrafish larvae indicates that Fe2O3@LH demonstrates good biosafety. This study demonstrates the considerable potential of Fe2O3@LH hydrogel for practical application in reducing Pb(II) levels in contaminated soil.

The biochar derived from Spirulina platensis for the adsorption of Pb and Zn and enhancing the soil physicochemical properties

Microalgae can be collected in large quantities and hold significant potential for environmental remediation, offering a cost-effective solution. This study explores the use of Spirulina platensis (SP) as feedstock for biochar production. SP contains abundant nitrogen-rich components, such as proteins, which can serve as nitrogen sources. We prepared SP-derived biochar through pyrolysis for the adsorption of Pb and Zn from aqueous solutions and used it as an amending agent to remediate heavy metal-contaminated agricultural soil. Pyrolysis of proteins in SP introduces nitrogen-functional groups, resulting in nitrogen-doped biochar. We investigated the surface chemical behavior of thermally treated SP using X-ray photoelectron spectroscopy and Fourier-transform infrared spectroscopy. Surface analysis revealed the presence of pyridine-N and pyrrole-N from protein pyrolysis products. The study also demonstrated that these functional groups affect interactions with heavy metals. Batch experiments examined the effects of pH and initial concentration on the adsorption of Pb and Zn using SP400 and SP600. Both types of biochar showed satisfactory performance in adsorbing Pb and Zn. The effect of SP400 and SP600 on the removal of Pb and Zn through the physicochemical properties and surface functional groups was investigated. Analysis of SP400 and SP600 highlighted that electrostatic interactions, cation exchange, complexation, and mineral precipitation contributed to Pb and Zn adsorption. The study concludes that SP-derived biochar, particularly SP600, is effective for immobilizing Pb and Zn in contaminated agricultural soil, with SP600 showing superior performance.

Preparation of sludge-derived spinel ferrite nanoparticles for highly efficient adsorption of Pb(II) from water: Adsorption behaviour and mechanism interpretation via advanced statistical physics model

Because proper disposals of municipal sewage sludge and lead-containing wastewater are still open questions, the novel sludge-derived mesoporous nanospinel ferrite adsorbents were prepared from municipal sewage sludge (S-MZF) and its incineration ash (A-MZF) for Pb(II) removal from water. S-MZF and A-MZF had similar mesoporous structures with an average pore size at around 4.13–5.51 nm. A-MZF displayed a larger specific surface area (254 m2/g) and pore volume (0.3 m3/g) but inferior magnetic property, while S-MZF showed abundant surface functional groups and higher saturation magnetization (12.3 emu/g). The adsorption capacity of S-MZF and A-MZF for Pb(II) was close to each other at 50 °C, reaching 160 mg/g. Initial adsorption of A-MZF for Pb(II) was dominated by intraparticle diffusion, while the evident liquid film diffusion existed in that of S-MZF. Advanced statistical physics modeling found that multiple divalent lead ions were anchored simultaneously by each site of S-MZF mainly via multi-interactions where physical force and precipitation played a key role, while each site of A-MZF anchored only one Pb(II) ion by the physical interaction. As a result, the adsorption capacity of S-MZF mainly depended upon the number of Pb(II) ions adsorbed by each active site, while the available density of active sites on the surface of A-MZF primarily controlled its adsorption capacity for Pb(II).

Removal of Pb(II) pollution by algae-Fe-Ni magnetic nanocomposite

A magnetic nanocomposite material was synthesized by combining Chaetomorpha Algae with a Fe–Ni alloy. The dry algae, Fe, and Ni were mechanically alloyed using a ball milling technique in an argon atmosphere. The resulting Algae-Fe-Ni Magnetic Nanocomposite (AFNMN) was characterized using various analytical techniques, including particle size distribution (PSD) analysis, Brunauer-Emmett-Teller (BET) surface area analysis, scanning electron microscopy (SEM), differential scanning calorimetry (DSC), vibrating sample magnetometry (VSM), atomic absorption spectroscopy (AAS), and Fourier transform infrared (FTIR) spectroscopy. Multiple isotherm models were employed to study the adsorption of Pb(II) ions onto the AFNMN material. Density functional theory (DFT) was applied to predict the most stable amino acids for the removal of Pb(II) pollutants from a set of 14 amino acids. To optimize the Pb(II) uptake performance, three key experimental parameters were fine-tuned: pH, temperature, and reactor vessel geometry. Four different optimization methods were utilized, including response surface methodology (RSM), fuzzy logic, adaptive network-based fuzzy inference system (ANFIS), and artificial neural network genetic algorithms (ANN-GA). Additionally, a heat transfer simulation was conducted to determine the optimal vessel positions for achieving the desired temperature variations within the reactor during the adsorption process.

Hollow microspheres of layered double hydroxides through surfactant-free method enhanced heavy metals removal from soil

A three-dimensional MgAl layered double hydroxides hollow microsphere (HMS-LDH) is fabricated by surfactant-free method. The microstructure and the formation mechanism of HMS-LDH are investigated by XRD (X-ray diffraction), SEM (Scanning Electron Microscope), EDS (Energy dispersive Spectrometer) and XPS (X-ray photoelectron spectrometer). The morphology of LDHs could be varied by changing the ratio of metal cations to urea. The adsorption properties of HMS-LDH for heavy metals from soil are investigated. The results of experiments demonstrates that the adsorption kinetics of Cu(Ⅱ), Pb(Ⅱ), As(Ⅴ), Cr(Ⅵ) are in good agreement with the pseudo-second-order kinetic and intraparticle diffusion model. The adsorption isotherm data of Cu(Ⅱ)/Pb(Ⅱ) is accordance with the Langmuir-Freundlich model, while the equilibrium adsorption of As(Ⅴ)/Cr(Ⅵ) follow the Generalized-Langmuir isotherm model well. Site energy distribution theory denotes the hollow microsphere structure increases the adsorption sites of heavy metals, which is conducive to the adsorption process. The different mechanisms of precipitation for Cu(Ⅱ)/Pb(Ⅱ) removal and interlayer adsorption for As(Ⅴ)/Cr(Ⅵ) removal are proposed. The effects of coexisting cations and column leaching experiments on the performance evaluation are also investigated, which indicate most the ions have no effect on the adsorption of Cu (Ⅱ)/Pb(Ⅱ) and As(Ⅴ)/Cr(Ⅵ). This work proposes a simple approach to prepare LDHs hollow microspheres and demonstrates their excellent properties for the remediation of heavy metal polluted soil.

Fabrication of Iron Oxide–Based Chitosan/CNF Bio-Green Composite for Pb(II) Removal from Synthetic Wastewater: Isotherm and Regeneration Studies

Fabrication of Iron Oxide–Based Chitosan/CNF Bio-Green Composite for Pb(II) Removal from Synthetic Wastewater: Isotherm and Regeneration Studies

Effects of active silicon amendment on Pb(II)/Cd(II) adsorption: Performance evaluation and mechanism

In this study, a high-Si (Si) adsorbent (APR@Sam) was prepared by acid leaching slag (APR) from lead-zinc (Pb-Zn) tailings based on high-temperature alkali melting technology. The synthesized Si-based materials were applied to aqueous solutions contaminated with Pb and cadmium (Cd) to investigate the crucial role of active Si in sequestering heavy metals. The adsorption capacities of APR@Sam and the Si-depleted material (APR@Sam-NSi) were studied under different pH and temperature conditions. The results showed that as the pH increased from 3 to 7, the adsorption capacity increased, the active Si content in the solution increased by 63 %, and the maximum pH of the solution after adsorption was 7.12. After the removal of active Si, the Pb (II) and Cd (II) adsorption capacities of APR@Sam decreased by 45 % and 11.96 %, respectively. OH- promoted the release of Si into the solution, enhancing the material's adsorption efficiency. The reaction mechanism is mainly attributed to surface complexation guided by Si-O and Si-O-Si bonds, metal cation exchange, and bidentate coordination. The results indicated that the Si component is critical for the removal of Pb (II) and Cd (II) by APR@Sam and provide valuable insights into resource recovery strategies from leaching residues.

Utilizing banana peduncle as an affordable bio-adsorbent for efficient removal of lead ions from water and industrial effluents

The use of efficient biobased materials for the treatment of heavy metal-contaminated wastewater has been demonstrated to be a highly effective method. The natural adsorbent banana peduncle has a lot of potential for treating wastewater because it is renewable, inexpensive, readily available, and environmentally benign. To learn more about the possible uses of these adsorbents, we synthesized them from banana peduncles and studied their shape, crystalline structure, and functional groups. The following parameters were found to be ideal for lead biosorption in batch trials concentrating on Pb (II) removal: a pH of 5, a contact period of 120 min, particle sizes between 240 and 300 mesh, concentrations at 40 mg/L, dosages of 3 g/L, and agitation rates of 200 revolutions per min (RPM). The banana peduncle showed an amazing biosorption efficiency of 94.0 % in the results. A comparison was made between the Freundlich, Langmuir, and Temkin models to investigate the adsorption isotherms of lead (II) ions. The R2 values obtained for these models were 0.9946, 0.9769, and 0.9537, respectively. Models that were pseudo-second-order and first-order were evaluated; the latter showed a better fit. The effectiveness and affordability of banana peduncle as the best adsorbent were highlighted by desorption testing. This study shows how materials made from banana peduncles can be an effective and sustainable way to reduce heavy-metal pollution in wastewater. This paper is the first to explore the potential absorption of Pb (II) by the peduncle of bananas, based on our current understanding.

Characteristics of Removal of Lead, Cadmium and Chromium from Soil Using Biosorbent and Biochar

The study proposed the use of aspen wood sawdust and biochar derived from this sawdust for the removal of Pb(II), Cd(II), and Cr(VI) ions from soil in systems containing single metals as well as a mixture of all the studied metals. The effectiveness of the applied sorbents was compared with the sorptive properties of activated carbon. The results showed that all the tested materials reduced the metal content in the soil, and the obtained biochar was able to sorb lead, cadmium, and chromium ions in both studied systems. The influence of the type of sorbent, its dose, process duration, and the impact of metal on the removal efficiency and sorption capacity was analyzed. A statistical analysis of the obtained results was also conducted, determining the influence of process parameters on the removal capabilities of metal ions. The highest Pb, Cd and Cr ion removal efficiencies were obtained in a 36-day process at a sorbent dose of 10%. Aspen sawdust, biochar and activated carbon removed 46%, 50% and 71% of Pb(II), 35%, 43% and 53% of Cd(II) and 15%, 27% and 38% of Cr(VI), respectively. In turn, the highest sorption capacity values were achieved in a 36-day process at a sorbent dose of 2%, obtaining results of 20.2 mg/g, 22.3 mg/g and 23.2 mg/g of Pb(II), 5.1 mg/g, 7.9 mg/g and 11.7 mg/g of Cd(II) and 3.8 mg/g, 5.8 mg/g and 8.5 mg/g of Cr(VI), respectively. It was found that both raw aspen wood sawdust and biochar derived from this wood are effective in removing toxic metal ions from soil, which presents a potential solution to their presence in the natural environment.

Remediation of water containing lead(II) using (3-iminodiacetic acid) propyltriethoxysilane graphene oxide

A novel chelating adsorbent based on (3-iminodiacetic acid) propyltriethoxysilane graphene oxide (IAT-GO) has been developed, showing exceptional promise for capturing lead. IAT-GO is made by combining a high-surface-area graphene oxide with a specially designed chelating ligand, which can selectively and efficiently remove lead. The synthesis of IAT-GO involves a two-step progression. In the first step, covalent bonds form between graphene oxide and (3-aminopropyl)-triethoxysilane (AT) through hydrolysis, condensation, and epoxide ring opening reactions. In the second step, nucleophilic substitution reactions occur between the primary amines and chloroacetic acid (CAA). A comprehensive suite of characterization techniques, including XPS, UV–Vis, XRD, Raman, FTIR, TEM, and SEM, provides detailed insights into the IAT-GO adsorbent's chemical composition and physical form, elucidating its intricate structure and morphology. Optimizing the experimental conditions for using the adsorbent material to remove Pb(II) ions from contaminated water revealed a maximum adsorption capacity of 124.0 mg/g at pH 5 and 30 min. The IAT-GO displays high selectivity for Pb(II) in a mixture of six metal ions containing 100 ppm of each one. Moreover, the IAT-GO shows 100% removal of Pb(II) for concentrations lower than 50 ppm. The excellent fit of the experimental data with the Langmuir adsorption isotherm and pseudo-second-order kinetic models (R2 > 99%) indicates that Pb(II) ion uptake onto the IAT-GO surface occurs via the monolayer formation of mercury ions. IAT-GO demonstrates exceptional potential as an innovative adsorbent for lead-contaminated water. Nitric acid (0.4 M) effectively regenerates the material, while its reusability remains impressive even after five cycles (> 97% removal efficiency). Therefore, this study highlights the development of a groundbreaking material, IAT-GO, with exceptional potential for remediating lead-contaminated water. Its high efficiency, selectivity, reusability, and cost-effectiveness make it a promising candidate for real-world applications.

Cellulose/castor oil‐based polyurethane film composite for aqueous Cd and Pb adsorption: Evaluation using laser‐induced breakdown spectroscopy

AbstractCastor oil‐based polyurethane has been researched for its utility in heavy metal adsorption. To improve the adsorptive performance, the polymer can be incorporated with cellulose—a renewable and widely available biopolymer. The aim of this research was to synthesize a film composite prepared from castor oil‐based polyurethane and cellulose for adsorptive removal of aqueous Cd and Pb. One‐shoot synthesis method was employed by mixing cellulose filler with castor oil and toluene diisocyanate (TDI). Characterization was carried out by FT‐IR, SEM, TGA, DSC, and contact angle analyses. Batch adsorption was carried out for the Cd and Pb with variations in contact time and initial pH, before analyzed for the adsorptive performance using 1064 nm Nd:YAG laser spectroscopy. The resulted adsorbents had improved thermal stability, and lower hydrophobicity. Adsorption of Pb and Cd increased 2 and 35 times after the addition of 0.1 g cellulose, respectively. Batch adsorption test revealed that the optimum conditions are 120‐min contact time and pH of 9 and 7 (for Cd and Pb, respectively). In conclusion, incorporation of cellulose could modify the characteristics of castor oil‐based polyurethane film and improve the adsorption of Cd and Pb.

Simultaneous removal of lead(II) and cadmium(II) from acidic wastewater by Fe-modified sludge biochar

In natural environments, heavy metal water pollution often involves simultaneous presence of various heavy metal ions (HMs), posing significant challenges for their removal. In this study, Fe-modified sludge biochar was synthesized via the co-precipitation method, and the effects of various environmental factors on simultaneously removing lead(II) and cadmium(II) by Fe@SBC were investigated. Batch adsorption experiments showed that Fe@SBC has a higher removal capacities for Pb(II) than for Cd(II) in both single or binary solutions. Increasing solution pH promoted the HMs removal on Fe@SBC. Coexisting divalent cations (Mg2+ and Ca2+) exhibited stronger inhibitory effects on HMs removal by Fe@SBC than monovalent cations (K+ and Na+). The presence of humic acid (HA) did not affect Pb(II) removal on Fe@SBC in either single or binary systems. In single systems, increasing HA concentration enhanced Cd(II) removing on Fe@SBC, while in binary systems, increasing HA concentrations inhibited the Cd(II) removal on Fe@SBC. The sorption of Pb(II) and Cd(II) on Fe@SBC followed the pseudo-second-order kinetic model and the Langmuir model. The removal mechanisms involved electrostatic interactions, complexation with O-containing group, and mineral dissolution-precipitation. After three regenerations, the adsorption capacity of Fe@SBC for Pb(II) and Cd(II) decreased by approximately 5–10 %. In summary, this environmentally friendly composite material has great potential for simultaneously remediating of Pb(II) and Cd(II).

Highly selective and efficient Pb2+ capture using PO4-loaded 3D-NiFe layer double hydroxides derived from MIL-88A

Lead (Pb) contamination in water requires improved decontamination technologies. The addition of phosphate to precipitate Pb2+ is a widely used method for remediating Pb in soil and water, though it has certain limitations. This study focuses on novel 3D mesoporous layered double hydroxide (LDH) sorbents functionalized with phosphate anions for Pb2+ removal from contaminated waters. Our innovative strategy involves converting a sacrificial template metal-organic frameworks (MOFs) structure (MIL-88A(Fe)) into NixFe LDH, followed by an anion exchange reaction with phosphate anions. This process preserves the 3D microrod architecture of MIL-88A and prevents deleterious LDH particle aggregation. The synthesis results in stable microrod crystals, 1–2 μm long, composed of 3D assemblies of NixFe-PO4 LDH nanoplatelets with a specific surface area exceeding 110 m2/g. The novel LDH materials display fast adsorption kinetics (pseudo-second order model) and remarkably high Pb2+ removal performances (Langmuir isotherm model) with a capacity of 538 mg/g, surpassing other reported adsorbents. LDH-PO4 exhibits high selectivity for Pb2+ over competing ions like Ni2+ and Cd2+ (selectivity order is: Pb2+ > Ni2+ > Cd2+). Removal of Pb2+ from NixFeLDH/88A-PO4 involves various mechanisms, including surface complexation and surface precipitation of lead phosphate or lead hydroxide phases as revealed by structural characterization techniques.

Comprehensive assessment of water pollution and health risks in the Angereb Reservoirs, Gondar, Ethiopia

Angereb Reservoirs are experiencing significant levels of pollution due to various anthropogenic activities such as agricultural runoff, untreated sewage discharge and industrial waste, were degrading water quality and causing eutrophication. Communities used Angereb Reservoir water is at increased risk of waterborne diseases; particularly heavy metal causes chronic health problems. However there was lack of comprehensive data on the cause and extent of pollution in the Angereb Reservoir. This comprehensive assessment highlights urgent need for integrated water resource management and effective pollution control strategies. This study was conducted through a multi-faceted and systematic approach involving several key methodologies. Six water samples were collected along the strategic points of the reservoir between May 2023 and March 2024. Different standard analytical methodologies were applied for analysis of water quality parameters including pH, dissolved oxygen, nutrients and heavy metals. The finding indicates that the concentration (mg/L) of heavy metals were Fe (0.01–6.56), Zn (0.67–5.22), Cu (0.009–0.19), Mn (0.0–1.89), Cr (5.06 × 10–5–0.03), Cd (0.029–0.27) and Pb (0.001–2.216). Cd and Pb were exceeded WHO for safe drinking water, heavy metal evaluation index values was > 10. Hazard Quotient (HQ), hazard index (HI) and incremental lifetime cancer risk (ILCR) were calculated. Average HQ values for Cd and Pb were above the risk threshold (HQ>1), indicating significant long-term exposure risks. HI>1 suggested potential non-carcinogenic effects. Furthermore, ILCR values exceeding 10–4 threshold, shows that Cd and Pb were the major risk factor for cancer particularly in children. The findings underscore the urgent need for Cd and Pb removal from Angereb reservoir.

Synthesis of amidoxime adsorbent prepared by radiation grafting on upcycled low-density polyethylene sheet for removal of heavy metals from wastewater

The issue of discharging waste, especially heavy metals from industrial activities into the environment, not only adversely impacts environmental quality but also has impacts on communities and human health. Removal and reduction of heavy metal contamination in rivers and wastewater are, therefore, critical initiatives that require significant attention. This work studied the removal of heavy metals, including Zn(II), Cu(II), As(III), and Pb(II) by utilizing an upcycled amidoxime low-density polyethylene sheet (AO-sheet). The synthesized AO-sheet was analyzed for various physical properties, including scanning electron microscope, energy-dispersive x-ray spectroscopy, Fourier transform infrared spectroscopy, and thermogravimetric analysis. For the batch adsorption experiment, parameters affecting adsorption capacity were studied: initial concentration, submerging time, and pH. Adsorption isotherms were also studied. The results of the heavy metal adsorption study showed that the initial concentration was the most significant parameter; the higher the initial concentration, the greater the adsorption capacity. The adsorption capacity of Zn(II) and Pb(II) increased with submersion time, which achieved 21.07 and 0.855 mg/g-adsorbent, respectively, after four weeks of submersion under the highest initial concentration studied. The adsorption capacity of Cu(II) was 7.98 mg/g-adsorbent after two weeks of optimal adsorption duration under the highest initial concentration studied. The adsorption capacity of As(II) was 1.07 mg/g-adsorbent after one week of optimal submersion time under the highest initial concentration studied. Moreover, the appropriate pH range for effective adsorption of Zn(II), Cu(II), and Pb(II) was identified as 8–9, while for As(III), it was 6–8, with an adsorption duration of 0.43 weeks (3 days). From the Langmuir isotherm, it was found that the adsorption of this work was characterized by monolayer adsorption. The results demonstrate that the AO-sheet can be effectively used to remove heavy metals from wastewater. Its potential for reusability was up to 8 cycles, with the Zn(II) adsorption capacity being reduced to about 20.37%.