Elimination Of Pb2 Research Articles

Effective adsorptive removal of Pb2+ ions from aqueous solution using functionalized agri-waste biosorbent: New green mediation via Seidlitzia rosmarinus extract

Currently, the use of natural adsorbent for the elimination of pollutants, such as heavy metals, from water has been extensively investigated. However, the low adsorption capacity of these natural adsorbents has led researchers towards the use of synthetic surfactants, which themselves can become environmental pollutants. In this research, an investigation was conducted to examine the impact of a surfactant obtained from the Seidlitzia rosmarinus plant on the adsorption properties of Pumpkin seed shell (PSS), a natural adsorbent. As a result, a modified version of PSS, known as functionalized Pumpkin seed shell (FPSS), was developed, and the effect of these two adsorbents on the elimination of Pb2+ has been investigated. FESEM, EDS, FTIR, and BET analyses were conducted to get detailed information of the adsorbent. Additionally, the effects of contact time, dosage of the adsorbent, pH of the solution, and temperature on the adsorbent were studied. The experimental data was fitted using Langmuir, Freundlich, Temkin, and Jovanovic isotherms. The PSS adsorbent was fitted best with the Langmuir isotherm, showing an adsorption capacity of 160.80 mg g−1, while the FPSS adsorbent was fitted with the Jovanovic isotherm, exhibiting an adsorption capacity of 553.57 mg g−1. Furthermore, kinetic modeling results indicated that the data for these adsorbents follow pseudo-second-order kinetic. Finally, the impact of coexisting ions and reusability was examined, with the FPSS adsorbent outperforming PSS. Therefore, the investigation of all these aspects demonstrated that the use of this natural surfactant significantly improves the performance of the adsorbent.

Enhancing irrigation water quality efficiently with potassium feldspar-derived adsorbent: Heavy metal detoxification and nutrient augmentation

The pollution of Pb2+ and Cd2+ in both irrigation water and soil, coupled with the scarcity of vital mineral nutrition, poses a significant hazard to the security and quality of agricultural products. An economical potassium feldspar-derived adsorbent (PFDA) was synthesized using potassium feldspar as the main raw material through ball milling-thermal activation technology to solve this problem. The synthesis process is cost-effective and the resulting adsorbent demonstrates high efficiency in removing Pb2+ and Cd2+ from water. The removal process is endothermic, spontaneous, and stochastic, and follows the quasi-second-order kinetics, intraparticle diffusion, and Langmuir model. The adsorption and elimination of Pb2+ and Cd2+ is largely dependent on monolayer chemical sorption. The maximum removal capacity of PFDA for Pb2+ and Cd2+ at room temperature is 417 and 56.3 mg·g−1, respectively, which is superior to most mineral-based adsorbents. The desorption of Pb2+/Cd2+ on PFDA is highly challenging at pH≥3, whereas PFDA and Pb2+/Cd2+ are recyclable at pH≤0.5. When Pb2+ and Cd2+ coexisted, Pb2+ was preferentially removed by PFDA. In the case of single adsorption, Pb2+ was mainly adsorbed onto PFDA as Pb2SiO4, PbSiO3·xH2O, Pb3SiO5, PbAl2O4, PbAl2SiO6, PbAl2Si2O8, Pb2SO5, and PbSO4, whereas Cd2+ was primarily adsorbed as CdSiO3, Cd2SiO4, and Cd3Al2Si3O12. After the complex adsorption, the main products were PbSiO3·xH2O, PbAl2Si2O8, Pb2SiO4, Pb4Al2Si2O11, Pb5SiO7, PbSO4, CdSiO3, and Cd3Al2Si3O12. The forms of mineral nutrients in single and complex adsorption were different. The main mechanisms by which PFDA removed Pb2+ and Cd2+ were chemical precipitation, complexation, electrostatic attraction, and ion exchange. In irrigation water, the elimination efficiencies of Pb2+ and Cd2+ by PFDA within 10 min were 96.0 % and 70.3 %, respectively, and the concentrations of K+, Si4+, Ca2+, and Mg2+ increased by 14.0 %, 12.4 %, 55.7 %, and 878 %, respectively, within 60 min. PFDA holds great potential to replace costly methods for treating heavy metal pollution and nutrient deficiency in irrigation water, offering a sustainable, cost-effective solution and paving a new way for the comprehensive utilization of potassium feldspar.

Removal of heavy metal ions from wastewater using ion exchange resin in a batch process with kinetic isotherm

Techniques such as selective ion exchange can be used to remove traces of heavy metals. The recently created resins provided quicker sorption kinetics and a high resin capacity for metal ions such as Lead (Pb²⁺), Copper (Cu²⁺), Zinc (Zn²⁺), Cadmium (Cd²⁺), and Nickel (Ni²⁺) ions. The elimination of Pb²⁺ and Cu²⁺ ions from aqueous solutions was examined in the current work. Purolite® C100, a strong acid cation-exchange resin, was used in experimental studies. Using packed-column chromatography, the impacts of operating factors on metal ion exchange were examined. These parameters included resin dose, initial pH, residence time, and metal ion concentration with ranges of 40 - 80 gs, 3 - 12, 30 - 90 min, and 50 -150 parts per million respectively. As part of exchange research, different doses of resin are brought into contact with a fixed volume of solution containing different concentrations and pHs of Pb²⁺ and Cu²⁺ ions for different periods. An Atomic Absorption Spectrophotometer (AAS) approach was used to measure the concentrations of metal ions. Experimental data on ion exchange were evaluated using Langmuir, Freundlich, and Temkin models.The results showed that there is a clear competition between lead and copper, as it was found that there is a convergence between the removal rates for both metals under the same conditions. The ion-exchange recovery of Cu approached 94.37 %, but Pb recovery was 92.9 % with Purolite® C100 resin dose range of 40 g to 80 g in the pH range of 3 to 12.

Development of a fabric phase sorptive extraction method using ethylenediamine tetra-acetic acid modifier for quantitative determination and elimination of Pb2+, Cu2+ and Zn2+ cations in real sample solutions

A novel and simple fabric phase sorptive extraction technique based on using ethylenediamine tetra-acetic acid (EDTA-FPSE), was used for selective solid phase extraction of Pb2+, Cu2+ and Zn2+ cations followed by using inductively coupled plasma-optical emission spectrometry (ICP-OES). Then, the synthesized adsorbent was characterized by field emission scanning electron microscopy (FESEM) and energy dispersive X-Ray (EDX) analysis. The effect of some parameters including pH of the sample solution, extraction time, sample solution volume and the type and concentration of desorbent solution was investigated and they were optimized in details. Under the optimum experimental conditions, the limits of detection (LOD) were found to be: 0.062, 0.032 and 0.036 µg/L for Pb2+, Cu2+ and Zn2+cations, respectively and the limits of quantification (LOQ) were equal to 0.18, 0.1 and 0.12 µg/L for Pb2+, Cu2+ and Zn2+cations, correspondingly. Also, the reusability of the synthesized EDTA based on fabric phase sorptive adsorbent, showed that for these metal cations, it could be used for at least 12 adsorption/desorption cycles. Adsorption mechanism was evaluated by different isotherm models and based on the obtained results, the adsorption of Pb2+, Cu2+ and Zn2+ cations is followed by Langmuir isotherm model with a maximum adsorption capacity of 92.60, 75.76 and 101.10 mg g−1 for Pb2+, Cu2+ and Zn2+cations, respectively. Finally, the selective behavior, high recovery percentage (more than 90 %), simple extraction procedure (easily separation of adsorbent from solution), makes the EDTA based on fabric phase sorptive extraction (EDTA-FPSE) technique as an unique technique for solid phase extraction of these heavy metal cations in different real sample solutions.

Novel Zn metal–organic framework with the thiazole sites for fast and efficient removal of heavy metal ions from water

Pollution of water by heavy metal ions such as Pb2+ and Hg2+ is considered as an important issue, because of the potential toxic effects these ions impose on environmental ecosystems and human health. A new Zn-based metal–organic framework, [Zn2(DPTTZ) (OBA)2] (IUST-2), was synthesized through a solvothermal method by the reaction of 2, 5-di (4- pyridyl) thiazolo [5, 4-d] thiazole ligand (DPTTZ), the “V-shape” 4,4'-oxybis (benzoic acid) ligand (OBA) and zinc nitrate (Zn(NO3)2·6H2O). This novel MOF has been characterized by several analysis techniques such as fourier transform infrared spectroscopy (FT-IR), elemental analysis (EA), powder x-ray diffraction (PXRD), thermogravimetry analysis (TGA), differential thermal analysis (DTA), field emission scanning electron microscopy (FE-SEM), Brunauer–Emmett–Teller (BET) surface area analysis and single-crystal X-ray diffraction (SXRD). This 3D MOF was tested for removing Pb2+ and Hg2+ ions from water. The factors that were investigated on the elimination of Pb2+ and Hg2+ ions were of pH, adsorption time, and the effect of initial ions concentration. According to the results, this particular Zn-MOF had significant performance in eliminating Pb2+ and Hg2+ ions from water with a removal efficiency of more than 97% and 87% within 3 min, respectively.

Study on the Combined Behaviour of Montmorillonite and Carbonate Mineralizing Bacteria on Lead Retention and Fixation

Heavy metal pollution management is a global environmental problem that poses a great threat to the ecological environment. Adsorption and biomineralization are considered to be the two most promising heavy metal pollution remediation techniques among the numerous available ones. In this work, a combined heavy metal removal system was constructed employing the adsorption of montmorillonite and the mineralization of carbonate mineralizing bacteria to expand their application potential for controlling heavy metal water pollution. Analysis of changes in pH, CO32− concentration, Pb2+ concentration in the liquid phase, and changes in microscopic morphology, mineral phase, and functional group on sedimentary minerals was done to study the retention and fixation behaviour of montmorillonite and carbonate mineralizing bacteria on Pb2+. The results show that the liquid phase pH may be slightly altered by the ions dissolved in montmorillonite. Based on the conditions of montmorillonite and carbonate mineralizing bacteria functioning separately, the elimination of Pb2+ may reach 35.31% and 45.75%, respectively. However, when montmorillonite is combined with carbonate mineralizing bacteria, which is the heavy metal removal system constructed in this study, montmorillonite can buffer part of the Pb2+ rapidly and reduce its biotoxicity. Subsequently, these buffered Pb2+ are gradually desorbed by carbonate mineralizing bacteria and removed by the effect of mineralized deposition. Results from SEM, FTIR, and XRD indicate that Pb2+ is primarily removed from the liquid phase as rod-shaped PbCO3. It is worth noting that this process is able to significantly increase the removal of Pb2+ up to 90.06%. In addition, the presence of carbonate mineralizing bacteria can increase montmorillonite’s desorption rate to over 81%, greatly enhancing its capacity for reuse. Therefore, our research work contributes to expanding the potential of montmorillonite and carbonate mineralizing bacteria in the treatment of heavy metal-polluted waters.

Lead Removal From Simulated Wastewater Using Magnetite As Adsorbent With Box–Behnken Design

The current education explores the magnetite aptitude by way of adsorbent in eliminating lead metal from simulated wastewater (SWW). The effect of magnetite dose, initial lead concentration, pH solution, and Adsorption time on the elimination procedure remained explored. The adsorbent remained considered through different instrumental methods (FTIR, SEM, and surface area analyzer) and was rummage-sale aimed at the elimination of Pb2+ metals from SWW. It remained initiate that the lead elimination touched 88.9 % through 0.3 g magnetite dose,75 min,2 ppm original concentration of lead thru pH = 6 at room temperature. The limits of adsorption were strong-minded aimed at heavy metals adsorption utilizing Langmuir and Freundlich isotherms. The consequences deliver robust evidence to support the adsorption mechanism hypothesis.

Engineered biochar with anisotropic layered double hydroxide nanosheets to simultaneously and efficiently capture Pb2+ and CrO42− from electroplating wastewater

Cationic and anionic heavy metal contaminants generally co-exist in practical industrial effluent, and simultaneously removal of these species is a bottleneck for most of the bio-adsorbents because of their contrary charge. In this work, pinewood sawdust derived engineered biochar (BC) was fabricated with MgAl layered double hydroxide (MgAl-LDH) nanosheets, which could efficiently and simultaneously capture heavy metal cations and oxyanions from wastewater. The synergetic effect between loaded MgAl-LDH and BC substantially improves its adsorption performance towards both cationic and anionic contaminants, i.e., Pb2+ and CrO42−. The adsorption capacity of MgAl-LDH/BC for Pb2+ reached 591.2 mg/g, which is 263% higher than that of BC, and in the case of CrO42−, the adsorption capacity is 330.8 mg/g, 416% higher than that of BC. The elimination of Pb2+ was mainly attributed to forming complexations with surface functional groups. While for oxyanions removal, CrO42− can be reduced to Cr3+ by functional groups, and then generated Cr3+ could replace Al3+ via morphic substitution, consequently formed an MgCr-LDH structure. Further, in the continuous fixed-bed column study, 225 bed volume of simulating electroplating wastewater co-existed with Pb2+ and CrO42− can be efficiently treated. Hence, this study sheds light on the engineered biochar design to efficiently and simultaneously capture heavy metal cations and oxyanions and its feasibility on real wastewater purification.

Microstructure-Related Pb2+ Adsorption Capability of Ti-Pillared Montmorillonite in Aqueous Solution

AbstractThe elimination of Pb2+ and recovery of lead metal during the treatment of industrial sewage is an important research topic. Montmorillonite (Mnt) is a promising material in this regard. The purpose of the present study was to improve the Pb2+ adsorption ability of Na-containing Mnt (Na-Mnt) by pillaring titania (anatase) into its interlayer spaces using a sol-gel method. The samples were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), and transmission electron microscopy (TEM). The ratio of Ti to Mnt affected the crystal phase of titania-pillared Na-Mnt (Ti-Mnt), and changed the interlayer spacing of the (001) plane of Ti-Mnt and the growth of anatase. The Pb2+-adsorption capabilities of Ti-Mnt were tested using an aqueous solution of lead nitrate as a wastewater model. The Ti-Mnt prepared adsorbed >99.99% of the Pb2+; leached and activated Ti-Mnt adsorbed >95.7% of the Pb2+, indicating that Ti-Mnt could be recycled effectively. Furthermore, the Pb2+-adsorption capability of Ti- Mnt was related to the interlayer spacing of Mnt, the distribution of anatase particles pillared in Mnt, and the specific surface area, especially with respect to the relationship between the anatase particles and the interlayer spacing of the (001) plane.

Applicability of electrochemical technologies for removing and monitoring Pb2+ from soil and water

This work examines electrokinetic remediation (ER) processes for removing Pb2+ in contaminated soils. For this purpose, different cathodic supporting electrolytes (NaNO3 0.1 M, EDTA 0.1 M and citric acid 0.1 M) were used into the catholyte reservoir, while in the anodic compartment, a solution of NaNO3 0.1 M was used. Additionally, the application of direct current (DC) and reverse polarity (RP) for removing of Pb2+ from the soil was also evaluated. Regarding to results obtained in this study indicated that RP and citric acid favored an efficient electromigration of Pb2+, favoring its elimination from the soil. This behavior can be explained because the elimination of Pb2+ depended on the dissolution/precipitation ionic species as well as the pH in the soil, which were maintaining in different sections in the soil, contributing to maintain the pH conditions, by using RP and citric acid, promoting the lead elimination. In order to use a feasible approach for monitoring Pb2+ concentration, adsorptive stripping voltammetry (AdSV) technique was used, obtaining acceptable confidence and good sensitivity for the concentration of Pb2+ with LOD about 0.1 mg L−1. Phytotoxicity tests showed that the ER process could be useful as a treatment technique for reducing hazardous soil toxicity polluted with Pb2+. The results confirmed the significant reduction of the germination in the anodic and cathodic regions for ER by applying DC with NaNO3 and EDTA as cathodic solutions. However, high germination (60–80%) was obtained for ER by using NaNO3 and citric acid solutions in cathodic compartments by applying RP or DC, respectively. Finally, the effluent generated by ER technology, in each one of experiments, was treated by electrocoagulation with Al electrodes, obtaining complete removal of Pb2+ from liquid after 60 min.

Identification of Splicing Quantitative Trait Loci (sQTL) in Drosophila melanogaster with Developmental Lead (Pb2+) Exposure.

Lead (Pb) poisoning has been a major public health issue globally and the recent Flint water crisis has drawn nation-wide attention to its effects. To better understand how lead plays a role as a neurotoxin, we utilized the Drosophila melanogaster model to study the genetic effects of lead exposure during development and identified lead-responsive genes. In our previous studies, we have successfully identified hundreds of lead-responsive expression QTLs (eQTLs) by using RNA-seq analysis on heads collected from the Drosophila Synthetic Population Resource. Cis-eQTLs, also known as allele-specific expression (ASE) polymorphisms, are generally single-nucleotide polymorphisms in the promoter regions of genes that affect expression of the gene, such as by inhibiting the binding of transcription factors. Trans-eQTLs are genes that regulate mRNA levels for many genes, and are generally thought to be SNPs in trans-acting transcription or translation factors. In this study, we focused our attention on alternative splicing events that are affected by lead exposure. Splicing QTLs (sQTLs), which can be caused by SNPs that alter splicing or alternative splicing (AS), such as by changing the sequence-specific binding affinity of splicing factors to the pre-mRNA. We applied two methods in search for sQTLs by using RNA-seq data from control and lead-exposed w1118 Drosophila heads. First, we used the fraction of reads in a gene that falls in each exon as the phenotype. Second, we directly compared the transcript counts among the various splicing isoforms as the phenotype. Among the 1,236 potential Pb-responsive sQTLs (p < 0.0001, FDR < 0.39), mostly cis-sQTLs, one of the most distinct genes is Dscam1 (Down Syndrome Cell Adhesion Molecule), which has over 30,000 potential alternative splicing isoforms. We have also identified a candidate Pb-responsive trans-sQTL hotspot that appears to regulate 129 genes that are enriched in the “cation channel” gene ontology category, suggesting a model in which alternative splicing of these channels might lead to an increase in the elimination of Pb2+ from the neurons encoding these channels. To our knowledge, this is the first paper that uses sQTL analyses to understand the neurotoxicology of an environmental toxin in any organism, and the first reported discovery of a candidate trans-sQTL hotspot.

Elimination of Pb2+ through electrocoagulation: Applicability of adsorptive stripping voltammetry for monitoring the lead concentration during its elimination

The aim of this manuscript is to develop a combined method for the detection and remediation of Pb2+ species in aqueous environment. The electrocoagulation (EC) process of Pb2+ has been studied, using an electrolytic flow cell equipped with Al sacrificial electrodes and by working under galvanostatic conditions (by applying currents of 0.25, 0.5 and 0.75A). The concentration of Pb2+ during EC was monitored by Adsorptive Stripping Voltammetry (AdSV) and data were also confirmed by Atomic Absorption Spectroscopy (AAS). The experimental results of EC showed that the performances of the process slightly depend on the applied current; a complete removal of the pollutant is obtained in all cases, however with different treatment times (90, 75 and 45min for 0.25, 0.5 and 0.75A, respectively). Furthermore, the AdSV, when compared with the AAS, has shown that the electroanalytical approach represents a fast and quite reliable alternative for monitoring heavy metal remediation applications.

Effects of magnetic field, pH and retention time on the lead (Pb2+) adsorption by modified human hair, goat hair and sheep wool

This research was carried out to investigate the removal of lead from water by modified sheep wool, human hair and goat hair because of their low cost than other methods. The modified keratin fibers by NaOH (0.1 N), is used in the elimination of Pb2+ ions from water. The effects of pH solution, initial concentration of lead in solution, retention time and magnetic field on elimination of Pb2+ were evaluated. The adsorption isotherms of Langmuir, Freundlich and BET models are used for adsorption of Pb2+ on modified sheep wool, human hair and goat hair (modified keratin fibers). Results showed that the adsorption power will better increase by fibers of pH~ 5.8 and one hour of retention time in magnetic field; so human hair is better than other fibers for removal of Pb2+. Based on the results, BET adsorption isotherm shows better adaptation in comparison with other cases. Key words: Pb2+ removal, modified keratin fibers, magnetic field, adsorption isotherm of Langmuir, Freundlich and BET models.