Lead Ion Concentration Research Articles

Application of an Electrochemical Sensor Based on Nitrogen-Doped Biochar Loaded with Ruthenium Oxide for Heavy Metal Detection

Cotton is a widely cultivated cash crop and represents one of the most significant raw materials for textiles on a global scale. The rapid development of the cotton industry has resulted in the production of substantial amounts of cotton husks, which are frequently underutilized or discarded. This study utilizes agricultural waste, specifically cotton shells, as a precursor for biochar, which is subsequently carbonized and nitrogen-doped with ruthenium oxide to synthesize an innovative composite material known as RuO2-NC. An electrochemical sensor was developed using this composite material to detect heavy metals, particularly lead and copper ions. The results demonstrate that the electrochemical sensor can accurately quantify concentrations of lead and copper ions across a wide linear range, exhibiting exceptional sensitivity. Furthermore, the sensor was tested on samples from Viola tianshanica Maxim (Violaceae) collected from the Xinjiang Uygur Autonomous Region (XUAR) in China, showing commendable accuracy and sensitivity. This approach promotes eco-friendly recycling of agricultural waste while offering advantages such as straightforward operation and reduced costs, thereby presenting promising prospects for practical applications.

Adsorption and separation of lead ions in phosphoric acid by co-doped carbon nanotubes with sulfur, oxygen, and manganese

Adsorption and separation of lead ions in phosphoric acid by co-doped carbon nanotubes with sulfur, oxygen, and manganese

A highly sensitive electrochemical sensor for the detection of lead(ii) ions utilizing rice-shaped bimetallic MOFs incorporated reduced graphene oxide.

The detection of lead ions (Pb2+) in water is of critical importance due to the harmful effects of lead on human health and the environment. Traditional detection methods often require high user expertise, expensive equipment, and complex analytical procedures. Electrochemical sensors have emerged as effective alternatives due to their portability and affordability. In this study, a novel electrochemical sensor was developed for the sensitive and selective detection of Pb2+ based on glassy carbon electrodes (GCE) modified with bimetallic metal-organic frameworks (MOFs) and reduced graphene oxide (rGO). The bimetallic MOFs were successfully synthesized via a hydrothermal method, combining two metal centers Fe and Mg linked to a 1,4-benzene dicarboxylate ligand (FeMg-BDC). The synthesized FeMg-BDC has higher conductivity and surface area than monometallic Fe-BDC or Mg-BDC MOFs. Thanks to the synergistic effects between FeMg-BDC and rGO, the rGO/FeMg-BDC electrode has a larger electrochemically active surface area and faster electron transfer rate than the bare GCE. This enhancement facilitated the accumulation of lead onto the electrode surface, thereby improving the sensitivity of Pb2+ ion detection. Using the square wave anodic stripping voltammetry method, the sensor based on rGO/FeMg-BDC electrode exhibited two linear ranges: 0.01 to 0.5 μg L-1 and 0.5 to 50.0 μg L-1, with a low limit of detection (LOD) of 9 ng L-1. Furthermore, the external rGO thin film protects the FeMg-BDC material on the electrode surface, ensuring high durability and repeatability of the sensor. The developed sensor was successfully applied to accurately determine lead ion concentrations in various real water samples.

A novel lateral flow assay for lead ion detection based on G-quadruplex

A novel lateral flow assay for lead ion detection based on G-quadruplex

Utilization of poly(methacrylic acid)‐rice straw graft copolymers for Pb2+ ions removal from wastewater: Synthesis, characterization, and adsorption studies

AbstractRice straw bio waste was converted into a high‐performance adsorbent for Pb2+ ions removal by grafting it with methacrylic acid using microwave irradiation. For this purpose, six levels of poly(MAA)‐rice straw graft copolymers having different graft yields % with increasing order and designated as (PMAARSGC‐I to PMAARSGC‐VI) were prepared and characterized using FTIR, SEM, XRD, TGA, zeta potential and BET analysis. Different factors affecting the Pb2+ removal expressed as adsorption capacity such as pH, extent of grafting, treatment time, and lead ions concentrations were studied in detail. Various kinetics models (pseudo‐first‐order, pseudo‐second‐order, Elovich, and intraparticle diffusion), isothermal (Langmuir, Freundlich, Temkin, and Dubinin–Radushkevich) and thermodynamic studies have been applied. The results demonstrated that (a) FT‐IR, SEM, XRD, TGA, zeta potential, and BET analysis confirmed the formation of carboxyl groups onto the graft copolymer, (b) the adsorption capacity increased with increasing the Pb2+ concentration and extent of grafting within the range studied; pH from 1 to 6; and the adsorption time up to 60 min then leveled off afterward, (c) maximum adsorption capacity of poly(MAA)‐rice straw graft copolymer was found to be 118 mg/g at pH 6, 200 mg/L lead ions concentration, adsorption time, 60 min, and 0.1 g adsorbent, (d) the kinetic and isothermal studies revealed that the privilege of Elovich model and pseudo‐second‐order rate equation as well the Langmuir model with more R2 value. The calculated thermodynamic parameters indicated that the adsorption process was achievable, spontaneous, and exothermic at 298–318 K. Finally, the preliminary adsorption mechanism representing the interaction between the adsorbent and adsorbate has been projected.

Modeling of adsorptive treatment of lead (II) ions contaminated effluents using cashew nut shell alkali activated carbon: Batch kinetic, isothermal and thermodynamic studies

Modeling of adsorptive treatment of lead (II) ions contaminated effluents using cashew nut shell alkali activated carbon: Batch kinetic, isothermal and thermodynamic studies

A ZnO-nanorod/PEDOT:PSS nanocomposite functionalized bridge-like membrane type nanomechanical sensing device for ultrasensitive blood lead detection

A ZnO-nanorod/PEDOT:PSS nanocomposite functionalized bridge-like membrane type nanomechanical sensing device for ultrasensitive blood lead detection

Rice husk biochar: production and sorption properties

Rice husk processing is not only a global problem, but also an acute one in Ukraine - utilization and processing of rice husks into a targeted secondary product is an urgent and promising task, given the volume of their accumulation. The purpose of this study is to obtain biochar that can be used efficiently and effectively in the anaerobic digestion process for biogas production and to determine its sorption characteristics. The results of determining the chemical composition of raw materials and biochar obtained by pyrolysis and microwave irradiation, with an increase in the pyrolysis temperature, the proportion of lignin and ash increases. Studies of the interaction of lead ions with plant material and its modified forms show that sorption by modified forms is much higher than by plant material, probably due to differences in chemical composition, surface properties, etc. Comparison of the data on the sorption of lead ions by modified forms (biochar) allows us to conclude that the method of preparation has a significant effect on the sorption value. The pyrolysis temperature of biochar has a favorable effect on the sorption properties of the samples. The obtained adsorption isotherms belong to the L-type. The maximum sorption values are observed under the experimental conditions at an initial concentration of lead ions of 1.00 mg/ml. The study of the kinetic parameters of the processes of lead ion sorption by biochar preparations based on the curve of residual lead ion concentrations shows that equilibrium in the system is achieved in a few hours. The rate of lead ion sorption increases with increasing pyrolysis temperature. The highest rate of lead ion sorption is observed for biochar obtained by using microwave irradiation. The maximum sorption values are observed after 2.5...3 hours of incubation. The value of lead ion sorption by Biochar-300 is 40.7 % after 3 hours of their joint incubation. An increase in the interaction time does not lead to a significant increase in the degree of sorption of lead ions by plant material and its modified forms.

Production of Industrial-Grade Monoclinic Lead Chromate (PbCrO4) from Indigenous Chromite ore for Paint Pigment Utilization

Decades of use have proven that lead chromate (PbCrO4) powder is an excellent paint pigment material. Unfortunately, practically this entire superb chromate compound used for decorative systems, protective systems, and mass dyeing of paper and polymer materials is conventionally made using inorganic synthetic chromium salts. In this study, we reported a promising simple, low-cost lead chromate production route derived from chromite ore from Nigeria. The Nigerian chromite ore was roasted in a 1:1 NaOH salt and then leached with water at 60°C. Lead nitrate was added to the leached liquor to further co-precipitate it. The resulting precipitate was then cleaned in ethanol and oven dried for ten hours at 80°C. The experimental results showed that lead ion concentration, temperature and flow rate have large influence on lead chromate precipitation, and the precipitation data fit a diffusion model. The activation energy of lead precipitation obtained was 4.76 kJ/mol, and the reaction order was 0.873 nearly one in relation to the concentration of lead ion. Additionally, XRD, FT-IR, and SEM/EDS comparative investigation of the properties established which favourable paint pigment performance similar to that of commercial industrial lead chromate powder in a range of all established physicochemical properties clarified the developing direction of research on lead chromate synthesis from Chromite leached liquor.

Electrospun Cellulose Acetate/Maleic Acid Functionalized Gold Nanoparticles as Pb(II) Ions Colorimeter Senser Strip

This study investigates the synthesis of gold nanoparticles and surface modifications to enable their utilization as a colorimetric sensor strip on electrospun nanofibrous. Additionally, it utilizes cellulose acetate electrospun fiber preparations as substrates for loading the gold nanoparticles. In order to produce gold nanoparticles, citrate reduction was employed, followed by modification with maleic acid (MA-GNPs). MA-GNPs were significantly more selective for Pb2+ than for other ions (Co2+, Cu2+, Hg2+, Ni+), according to the results. Following the introduction of Pb2+, the solutions exhibited a color change from red to blue or purple, which was attributed to the aggregation of nanoparticles, as determined by UV-Vis spectrometry. An optical band indicative of GNPs and MA-GNPs was detected at an estimated wavelength of 520 nm. Approximately 600 nanometers after the addition of Pb2+, the intensity of the solution progressively decreased to 520 nanometers, and a new band emerged. To fabricate cellulose acetate nanofibrous via electrospinning, the impact of solvent ratios, polymer concentrations, and process conditions were investigated. The ideal parameters for the fabrication of the substrate were as follows: 15%w/w polymer solution, 15 kV electrospinning voltage, 15 cm needle-to-collector distance, and 48 hours of collecting time. In order to examine the color change of the prepared strip, it is observed that the strip transforms from red to blue upon exposure to Pb2+ ions of varying concentrations, just as it does in solution form. An examination of water samples indicated that the strip remained colorless when tested with DI water. However, testing with wastewater sourced from a battery facility identified a transformation of the strip from red to purplish blue. This is equivalent to an estimated lead concentration of 40 parts per million. The outcomes showcased the capacity of the discolored strips to identify the preliminary concentration of lead ions, suggesting potential for future advancements in this area.

Determination of the Localized Surface Plasmon Resonance Alteration of AgNPs via Multiwavelength Evanescent Scattering Microscopy for Pb(II) Detection.

We developed multiwavelength evanescent scattering microscopy (MWESM), which can acquire plasmonic nanoparticle images at the particle level using the evanescent field as the incident source and distinguish different LSPR (localized surface plasmon resonance) spectral peaks among four wavelengths. Our microscope could be easily and simply built by modifying a commercial total internal reflection fluorescence microscope (TIRFM) with the substitution of a beamsplitter and the addition of a semicircular stop. The ultrathin depth of illumination and rejection of the reflected incident source together contribute to the high sensitivity and contrast of single nanoparticle imaging. We first validated the capability of our imaging system in distinguishing plasmonic nanoparticles bearing different LSPR spectral peaks, and the results were consistent with the scattering spectra results of hyperspectral imaging. Moreover, we demonstrated high imaging quality from the aspects of the signal/noise ratio and point spread function of the single-particle images. Meaningfully, the system can be utilized in rapidly determining the concentration of toxic lead ions in environmental and biological samples with good linearity and sensitivity, based on single-particle evanescent scattering imaging through the detection of the alteration of the LSPR of silver nanoparticles. This system holds the potential to advance the field of nanoparticle imaging and foster the application of nanomaterials as sensors.

Valorization of castor seed shell waste as lead adsorbent by treatment with hot phosphoric acid: Optimization and evaluation of adsorption properties

Valorization of castor seed shell waste as lead adsorbent by treatment with hot phosphoric acid: Optimization and evaluation of adsorption properties

Magnetic and PEG-crosslinked poly(methyl acrylate) functionalized with triethylenetetramine for removal of lead ions from contaminated water

Magnetic and PEG-crosslinked poly(methyl acrylate) functionalized with triethylenetetramine for removal of lead ions from contaminated water

Improved Microelectrode Array Electrode Design for Heavy Metal Detection

Traditional working electrodes are not sufficient to realize the low detection limit and wide detection range necessary for the detection of heavy metals. In this study, a microelectrode array electrode was proposed using a design scheme based on microelectromechanical systems that was optimized with finite element software. The working electrode adopted an innovative composite structure to realize the integrated design of the working and counter electrodes, which improved the system integration. Performance tests showed that the electrode realized the quantitative analysis of Cd(II), Pb(II), and Cu(II) with a low detection limit (0.1 μg/L) and a wide detection range (0.1–3000 μg/L). The electrode successfully measured the lead and copper ion concentrations in the Sanya River, including both seawater and freshwater environments. The experimental results demonstrate that the electrode exhibits excellent adaptability to environmental conditions and can be potentially applied for technical support in environmental monitoring and sewage treatment.

Influential biosorption of lead ions from aqueous solution using sand leek (Allium scorodoprasum L.) biomass: kinetic and isotherm study

AbstractIn this study, a zero-cost, naturally effective adsorbent, sand leek (Allium scorodoprasum L.), was used for the effective removal of lead ions from an aqueous solution. This natural adsorbent was characterized by FT-IR, SEM–EDX, and PZC analyses. Batch studies were conducted at one factor at a time to explore maximum removal efficiency in terms of pH, initial lead(II) ion concentration, contact time, adsorbent dosage, and temperature for efficient adsorption. The maximum lead(II) ion uptake capacity for SAC was obtained at pH 4.5, initial lead(II) ion concentration at 1000 mg/L, operation time of 1440 min, adsorbent dosage of 10 g, and temperature of 25 °C. The adsorption data were well-fitted by the Freundlich isotherm model, with an R2 value of 1.000, indicating a good fit. The kinetic study revealed that the adsorption of lead(II) ions followed a pseudo-first-order kinetic model, with an R2 value of 0.9746. Furthermore, the thermodynamic parameters including Gibbs-free energy change (ΔG°), enthalpy change (ΔH°), and entropy change (ΔS°) were calculated to demonstrate that the adsorption of lead(II) ions onto natural adsorbent was endothermic and spontaneous.

REMOVAL OF LEAD ION (Pb2+) FROM SYNTHETIC WASTEWATER USING SUGARCANE BAGASSE

High concentrations of Lead ions (Pb2+) in wastewater effluent can be detrimental to health and the environment. The objective of this research is to investigate the potential of sugarcane bagasse, for the removal of lead ions from synthetic wastewater. Adsorption studies were conducted using the batch technique. The effect of varying contact time was examined and the optimum absorption was recorded at 30 minutes with 72.89 % removal efficiency. The effect of adsorbent was investigated by exposing adsorbents of varying dosages of the media. Where 3g of sugar cane bagasse was found to be optimum absorption with 77.113 % removal efficiency. The effect of the size of the adsorbent dosage was investigated by exposing adsorbents to varying mesh sizes. The optimum absorption was found at 2mm size with 88.89 % removal efficiency. The effect of shaking speed on the removal of Pb2+ by sugarcane bagasse was investigated by exposing the adsorbent to varying shaking rates. The optimum absorption of 88.96 % efficiency was attained at 60 rpm. It was concluded that the adsorption of Pb2+ using clean sugarcane bagasse is a viable and environmentally friendly means of treating polluted wastewater.

Screen-Printed Carbon Electrode Modified with Carbon Nanotubes and Copper Film as a Simple Tool for Determination of Trace Concentrations of Lead Ions.

A copper film-modified, carboxyl-functionalized, and multi-walled carbon nanotube (MWCNT-COOH)-modified screen-printed carbon electrode (CuF/MWCNTs/SPCE) was used for lead determination using anodic stripping voltammetry. The main parameters were investigated and optimized during the development of the research procedure. The most optimal electrolyte concentrations were determined to be 0.4 M HCl and 6.3 × 10-5 M Cu(II). The optimal parameters for voltammetric stripping measurements are as follows: an accumulation potential of -0.7 V; an accumulation time of 120 s; and a pulse amplitude and pulse time of 120 mV and 2 ms, respectively. The effect of surface active substances and humic substances as potential interferents present in aqueous environmental samples was investigated. The validation of the procedure was carried out using certified reference materials, like waste water SPS-WW1 and environmental matrix TM-25.5. In addition, the developed procedure was applied to investigate lead recovery from natural environmental water, such as rivers and lakes.

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

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

Insight into the interaction of tetrabromobisphenol A with sediment-derived dissolved organic carbon in a multiphase system by direct immersion solid phase microextraction

Insight into the interaction of tetrabromobisphenol A with sediment-derived dissolved organic carbon in a multiphase system by direct immersion solid phase microextraction

Roughness Factors of Electrodeposited Nanostructured Copper Foams

Copper-based electrocatalytic materials play a critical role in various electrocatalytic processes, including the electroreduction of carbon dioxide and nitrate. Three-dimensional nanostructured electrodes are particularly advantageous for electrocatalytic applications due to their large surface area, which facilitates charge transfer and mass transport. However, the real surface area (RSA) of electrocatalysts is a crucial parameter that is often overlooked in experimental studies of high-surface-area copper electrodes. In this study, we investigate the roughness factors of electrodeposited copper foams with varying thicknesses and morphologies, obtained using the hydrogen bubble dynamic template technique. Underpotential deposition (UPD) of metal adatoms is one of the most reliable methods for estimating the RSA of highly dispersed catalysts. We aim to illustrate the applicability of UPD of lead for the determination of the RSA of copper deposits with hierarchical porosity. To find the appropriate experimental conditions that allow for efficient minimization of the limitations related to the slow diffusion of lead ions in the pores of the material and background currents of the reduction of traces of oxygen, we explore the effect of lead ion concentration, stirring rate, scan rate, monolayer deposition time and solution pH on the accuracy of RSA estimates. Under the optimized measurement conditions, Pb UPD allowed to estimate roughness factors as high as 400 for 100 µm thick foams, which translates into a specific surface area of ~6 m2·g−1. The proposed measurement protocol may be further applied to estimate the RSA of copper deposits with similar or higher roughness.