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Ultrafiltration (UF) have long been a leading separation technology with a strong historic track record for a wide range of applications such as the treatment of groundwater and wastewater. The fast development of techniques for producing nanostructured materials and nanoparticles has led to breakthroughs in a membrane preparation. In the present work, polyvinylidene fluoride (PVDF) based nanocomposite membranes modified with zinc oxide (ZnO), polydopamine (PDA), and ZnO/PDA powders were fabricated using phase inversion technique. ZnO/PDA nanoparticles, which were synthesized via sol-gel method, were incorporated into the membrane matrix by blending and PDA powders were incorporated into the PVDF membrane matrix by coating methods. Surface and cross-sectional morphology, thermal behavior, and mechanical strength of the membranes were characterized using both analytical techniques and instruments. Filtration performance of nanocomposite membranes was tested in terms of water flux, sodium alginate (SA) rejection, and antifouling properties in comparison to those of pristine PVDF membrane. Moreover, lead (Pb+2) removal of the prepared membranes from aqueous solutions complexed with chitosan was thoroughly investigated. Although modification of pristine PVDF membrane using different powders could not improve water flux and SA rejections substantially, anti-fouling properties could be enhanced markedly. PVDF/ZnO/PDA membrane was found to exhibit the best performance in filtration experiments with 92% flux recovery ratio and 97% SA rejection and had the highest lead removal (88.5%) from aqueous solutions.

ABSTRACT. In this study, the natural clay was modified and removal of Pb2+ ions synthetically prepared aqueous solutions using this modified clay was investigated. The parameters affecting the adsorption efficiency were examined in the study. In the result of studies, the suitability of the adsorption data to classic adsorption models, and adsorption kinetics were determined. In the experiments, it has been determined that pH 5 provides optimum removal conditions of adsorption and adsorption reached equilibrium in approximately 15 min. The highest removal efficiency was found to be 82.13% with the addition of 3 g L-1 adsorbent at a stirring speed of 200 rpm. As the lead concentration of the wastewater increases, the amount of lead retained per dry unit weight of the modified natural clay also increases. Experimental data showed that Pb2+ removal was consistent with Temkin adsorption model. Calculated thermodynamic constants showed that adsorption is exothermic and physical. KEY WORDS: Adsorption, Isotherm, Lead removal, Natural clay, Thermodynamic constants Bull. Chem. Soc. Ethiop. 2023, 37(1), 231-244. DOI: https://dx.doi.org/10.4314/bcse.v37i1.18 &nbsp

Real water remediation is an important issue that requires the development of novel adsorbents with remarkable adsorption properties, permitting reusability. In this work, the surface and adsorption properties of bare magnetic iron oxide nanoparticles were systematically studied, before and after the application of a maghemite nanoadsorbent in two real Peruvian effluents severely contaminated with Pb(II), Pb(IV), Fe(III), and others. We were able to describe the Fe and Pb adsorption mechanisms that occurred at the particle surface. 57Fe Mössbauer and X-ray photoelectron spectroscopy results together with kinetic adsorption analyses gave evidence for two involved surface mechanisms: (i) surface deprotonation of maghemite nanoparticles (isoelectric point of pH = 2.3), forming Lewis sites bonding Pb complexes; and (ii) the formation of a thin inhomogeneous secondary layer of iron oxyhydroxide and adsorbed Pb compounds, as favored by surface physicochemical conditions. The magnetic nanoadsorbent enhanced the removal efficiency to values of ca. 96% and provided adsorptive properties with reusability due to the conserved morphological, structural, and magnetic properties. This makes it favorable for large-scale industrial applications.

Development of polymeric magnetic adsorbents is a promising approach to obtain efficient treatment of contaminated water. However, the synthesis of magnetic composites involving multiple components frequently involves tedious preparation steps. In the present study, a magnetic chitosan-palygorskite (MCP) nanocomposite was prepared through a straight-forward one pot synthesis approach to evaluate its lead (Pb2+) removal capacity from aqueous solution. The nano-architectural and physicochemical properties of the newly-developed MCP composite were described via micro- and nano-morphological analyses, and crystallinity, surface porosity and magnetic susceptibility measurements. The MCP nanocomposite was capable to remove up to 58.5 mg Pb2+ g−1 of MCP from water with a good agreement of experimental data to the Langmuir isotherm model (R2 = 0.98). The Pb2+ adsorption process on MCP was a multistep diffusion-controlled phenomenon evidenced by the well-fitting of kinetic adsorption data to the intra-particle diffusion model (R2 = 0.96). Thermodynamic analysis suggested that the adsorption process at low Pb2+ concentration was controlled by chemisorption, whereas that at high Pb2+ concentration was dominated by physical adsorption. X-ray photoelectron and Fourier transform infrared spectroscopy results suggested that the Pb adsorption on MCP was governed by surface complexation and chemical reduction mechanisms. During regeneration, the MCP retained 82% Pb2+ adsorption capacity following four adsorption–desorption cycles with ease to recover the adsorbent using its strong magnetic property. These findings highlight the enhanced structural properties of the easily-prepared nanocomposite which holds outstanding potential to be used as an inexpensive and green adsorbent for remediating Pb2+ contaminated water. Refereed/Peer-reviewed

In this study, hydrothermal carbonization (HTC) at five temperatures (180, 200, 220, 240, and 260 °C) was applied to transform Paulownia leaves (PL) into a carbonaceous sorbent of Pb(II) from aqueous solutions. To enhance the adsorption efficiency of the obtained hydrochar (PH), subsequent alkali activation was performed using NaOH. Preliminary results of the Pb(II) adsorption (CPb = 200 mg/L) showed removal coefficients after 48 h of 73.44 mg/g, 82.37 mg/g, and 110.9 mg/g for PL, PH-220, and MPH-220, respectively. The selected hydrochar (PH-220) and modified hydrochar (MPH-220) were further investigated by scanning electron microscopy (SEM) and Fourier transform infrared spectroscopy (FTIR). The results revealed that alkali treatment changed the hydrochar structure and, thus, improved its adsorption performance. The kinetic parameters showed that the Pb(II) sorption onto MPH-220 followed a pseudo-second-order model, while the intra-particle diffusion went through two simultaneous stages. The Langmuir isotherm model best described the experimental data and indicated the value of 174.75 mg Pb(II)/g as the maximum adsorption capacity. The two possible mechanisms of Pb(II) binding were complexation and/or Pb-π electron interaction. The obtained results indicate the great potential of MPH-220 for Pb(II) removal from aqueous media and its potential utilization as an effective adsorbent for wastewater purification.

Zeolitic imidazolate frameworks (ZIFs) are increasingly gaining attention in many application fields due to their outstanding porosity and thermal stability, among other exceptional characteristics. However, in the domain of water purification via adsorption, scientists have mainly focused on ZIF-8 and, to a lesser extent, ZIF-67. The performance of other ZIFs as water decontaminants is yet to be explored. Hence, this study applied ZIF-60 for the removal of lead from aqueous solutions; this is the first time ZIF-60 has been used in any water treatment adsorption study. The synthesized ZIF-60 was subjected to characterization using FTIR, XRD and TGA. A multivariate approach was used to investigate the effect of adsorption parameters on lead removal and the findings revealed that ZIF-60 dose and lead concentration are the most significant factors affecting the response (i.e., lead removal efficiency). Further, response surface methodology-based regression models were generated. To further explore the adsorption performance of ZIF-60 in removing lead from contaminated water samples, adsorption kinetics, isotherm and thermodynamic investigations were conducted. The findings revealed that the obtained data were well-fitted by the Avrami and pseudo-first-order kinetic models, suggesting that the process is complex. The maximum adsorption capacity (qmax) was predicted to be 1905 mg/g. Thermodynamic studies revealed an endothermic and spontaneous adsorption process. Finally, the experimental data were aggregated and used for machine learning predictions using several algorithms. The model generated by the random forest algorithm proved to be the most effective on the basis of its significant correlation coefficient and minimal root mean square error (RMSE).

In this work, polyethyleneimine-grafted graphene oxide (PEI/GO) is synthesized using graphene, polyethyleneimine, and trimesoyl chloride. Both graphene oxide and PEI/GO are characterized by a Fourier-transform infrared (FTIR) spectrometer, a scanning electron microscope (SEM), and energy-dispersive X-ray (EDX) spectroscopy. Characterization results confirm that polyethyleneimine is uniformly grafted on the graphene oxide nanosheets and, thus, also confirm the successful synthesis of PEI/GO. PEI/GO adsorbent is then evaluated for the removal of lead (Pb2+) from aqueous solutions, and the optimum adsorption is attained at pH 6, contact time of 120 min, and PEI/GO dose of 0.1 g. While chemosorption is dominating at low Pb2+ concentrations, physisorption is dominating at high concentrations and the adsorption rate is controlled by the boundary-layer diffusion step. In addition, the isotherm study confirms the strong interaction between Pb2+ ions and PEI/GO and reveals that the adsorption process obeys well the Freundlich isotherm model (R2 = 0.9932) and the maximum adsorption capacity (qm) is 64.94 mg/g, which is quite high compared to some of the reported adsorbents. Furthermore, the thermodynamic study confirms the spontaneity (negative ΔG° and positive ΔS°) and the endothermic nature (ΔH° = 19.73 kJ/mol) of the adsorption process. The prepared adsorbent (PEI/GO) offers a potential promise for wastewater treatment because of its fast and high uptake removal capacity and could be used as an effective adsorbent for the removal of Pb2+-ions and other heavy metals from industrial wastewater.

In view of the increasing complexity of both cardiovascular implantable electronic devices (CIEDs) and patients in the current era, practice guidelines, by necessity, have become increasingly specific. This document is an expert consensus statement that has been developed to update and further delineate indications and management of CIEDs in pediatric patients, defined as ≤21 years of age, and is intended to focus primarily on the indications for CIEDs in the setting of specific disease categories. The document also highlights variations between previously published adult and pediatric CIED recommendations and provides rationale for underlying important differences. The document addresses some of the deterrents to CIED access in low- and middle-income countries and strategies to circumvent them. The document sections were divided up and drafted by the writing committee members according to their expertise. The recommendations represent the consensus opinion of the entire writing committee, graded by class of recommendation and level of evidence. Several questions addressed in this document either do not lend themselves to clinical trials or are rare disease entities, and in these instances recommendations are based on consensus expert opinion. Furthermore, specific recommendations, even when supported by substantial data, do not replace the need for clinical judgment and patient-specific decision-making. The recommendations were opened for public comment to Pediatric and Congenital Electrophysiology Society (PACES) members and underwent external review by the scientific and clinical document committee of the Heart Rhythm Society (HRS), the science advisory and coordinating committee of the American Heart Association (AHA), the American College of Cardiology (ACC), and the Association for European Paediatric and Congenital Cardiology (AEPC). The document received endorsement by all the collaborators and the Asia Pacific Heart Rhythm Society (APHRS), the Indian Heart Rhythm Society (IHRS), and the Latin American Heart Rhythm Society (LAHRS). This document is expected to provide support for clinicians and patients to allow for appropriate CIED use, appropriate CIED management, and appropriate CIED follow-up in pediatric patients.

The nanomaterials’ toxicity to aquatic life is a big issue due to improper handling or incomplete separation after use. The immobilization of the nanomaterials in the polymeric matrix could be a practical approach to developing an efficient hybrid composite for wastewater purification. In this study, AlOOH nanoparticles were immobilized in the polystyrene polymeric matrix to prepare an effective adsorbent to scavenge the Pb(II) from the aqueous solution. The synthesized polystyrene/AlOOH (PS/AlOOH) hybrid was characterized using microscopic techniques coupled with elemental mapping and EDX, X-ray diffraction, and a furrier-transformed infrared spectrometer. The results revealed that the Pb(II) adsorption onto the polystyrene/AlOOH composite depends on the solution pH, the Pb(II) concentrations in the solution, the adsorption time, and the solute temperature. The maximum scavenging of Pb(II) occurs at pH 6 in 90 min. The adsorption of Pb(II) onto PS/AlOOH decreases from 97.7% to 58.5% with the increase in the Pb(II) concentration from 20 mg g−1 to 100 mg g−1. The kinetics and isotherm modeling demonstrated that Pb(II) adsorption is well suited for the pseudo-second-order kinetics and Toth isotherm models, suggesting that the chemisorption occurs at the heterogeneous surface of PS/AlOOH. The PS/AlOOH composite could be used multiple times without a significant loss in the adsorption efficiency. These results demonstrated that the polystyrene/AlOOH composite is an effective material for the purification of wastewater and can be used on a large scale.

Background Cardiac implantable electronic device (CIED) implantation rate has been increasing worldwide. Despite proper surgical technique and preincisional intravenous antibiotics, the incidence of infected CIED remains high and leads to serious complications. When encountered with CIED infection, complete CIED system removal is indicated. Several lead extraction approaches have shown a high success rate. However, the facilities are limited in Thailand. In our current practice, we perform lead extraction using the Dotter basket snare femoral approach as our primary method. There are no prior data on this countertraction‐assisted transfemoral technique. Therefore, we aim to study the procedural outcome of countertraction‐assisted transfemoral lead removal technique of CIED infection in Thai patients. Methods Patients diagnosed with CIED infection and with a history of device infection were retrospectively included. Simple manual removal was performed. In case of failure, we proceeded with the modified countertraction‐assisted transfemoral technique. Results There were 35 patients in the study. The success rate was 94.3%. Most of the leads, 62.8%, were removed by simple manual traction. In the 37.1% who required further femoral approach lead extractions, procedural failure was observed in 5.7% and procedure‐related adverse events in 5.6%. CIED infection‐related death accounted for 5.7% and nosocomial infection‐related death, 2.8%. Conclusion The success rate of CIED infection lead explant and countertraction‐assisted transfemoral lead extraction technique was high with small complications and can be performed without advanced facilities. However, the procedure required a main center with a cardiovascular thoracic surgery support team., Countertraction is the cornerstone of the lead extraction in preventing of right ventricular (RV) inversion with less complications. Improvised technique, using telescopic system consisted of ablation catheter and deflectable sheath placement at RV apex, provided countertraction force whilst applying femoral lead extraction.

Hydroxamic acids are recognized chelators for various metals; however, using them as functional groups on carbon nanotubes (CNTs) is rare. In this study, novel multi-walled carbon nanotubes (MWCNTs) functionalized with hydroxamic acid derivatives were developed. The MWCNTs were first oxidized, and the resulting product, MWCNT-COOH (A), was treated with oxalyl chloride to yield MWCNT-COCl. The functionalized MWCNTs were susceptible to reacting with the hydroxylamine derivatives of type R–NHOH and produced MWCNTs functionalized with the following hydroxamic acid derivatives (MWCNT-HA): MWCNT-CONOHMe (B), MWCNT-CONOHCOMe(C), and MWCNT-CONOHPh (D). The synthesized derivatives were confirmed by various techniques such as scanning electron microscopy, X-ray photoelectron spectroscopy, and Raman spectroscopy. In order to examine their chelation ability, these materials were examined as possible new adsorbents for harmful Pb(II) particles. The adsorption efficiency of the functionalized MWCNT adsorbents toward Pb(II) was investigated. The effects of the adsorbent dose, temperature, pH, and time on adsorption efficiency were considered, and adsorption boundaries that resulted in enhanced effectiveness were obtained. The developed materials were found to have extraordinary coordination sites, such as amine, hydroxyl, and carboxyl groups, which served as excellent chelating specialists for the Pb(II) particles. Thermodynamic and kinetic investigations revealed the unconstrained nature of the adsorption of Pb(II) by the developed MWCNT adsorbents at room temperature. The adsorption was noted to follow the pseudo-second-order and Langmuir isotherm models.

This paper presents the development of a compact, three-electrode electrochemical device functionalized by a biocompatible layer of hyaluronic acid methacrylate (HAMA) hydrogel for the adsorptive removal of detrimental lead (Pb(II)) ions in aqueous solutions. An adsorption mechanism pertaining to the observed analytical performance of the device is proposed and further experimentally corroborated. It is demonstrated that both the molecular interactions originating from the HAMA hydrogel and electrochemical accumulation originating from the electrode beneath contribute to the adsorption capability of the device. Infrared spectral analysis reveals that the molecular interaction is mainly induced by the amide functional group of the HAMA hydrogel, which is capable of forming the Pb(II)–amide complex. In addition, inductively coupled plasma mass spectrometric (ICP-MS) analysis indicates that the electrochemical accumulation is particularly valuable in facilitating the adsorption rate of the device by maintaining a high ion-concentration gradient between the solution and the hydrogel layer. ICP-MS measurements show that 94.08% of Pb(II) ions present in the test solution can be adsorbed by the device within 30 min. The HAMA hydrogel-modified electrochemical devices exhibit reproducible performance in the aspect of Pb(II) removal from tap water, with a relative standard deviation (RSD) of 1.28% (for n = 8). The experimental results suggest that the HAMA hydrogel-modified electrochemical device can potentially be used for the rapid, on-field remediation of Pb(II) contamination.

In this study, treatment of lead containing wastewater using sewage sludge ash obtained from the incineration unit in the domestic wastewater treatment plant in Gaziantep province in Turkey was investigated. The main purpose of the study is to determine the potential of using the treatment sludge ash, which comes out as waste in the treatment plant, in the treatment of wastewater of another industry. As a result of this study, the most suitable adsorption conditions were determined and focused on the kinetics of adsorption. In the experiments, the lead adsorption capacity of sewage sludge ash was determined as 122 mg g-1 at 0.5 g L-1 adsorbent concentration in wastewater containing 100 mg L-1 Pb2+ under optimum conditions. As a result of the research, it was determined that the adsorption reaction proceeds according to the pseudo second degree reaction and is suitable for the Langmuir isotherm. As thermodynamic constants, ΔH° = 7.407 kJ mol-1 and ΔS° = 33.25 J mol-1 were determined. As a result of this, it was determined that the adsorption reaction was endothermic, spontaneous and random, and adsorption was physical adsorption. The results show that sewage sludge ash can be used in the treatment of water containing high concentrations of Pb2+. KEY WORDS: Adsorption, Heavy metal, Lead removal, Sewage sludge ash Bull. Chem. Soc. Ethiop. 2022, 36(4), 935-948. DOI: https://dx.doi.org/10.4314/bcse.v36i4.18 &nbsp

A key problem associated with the design of graphene oxide (GO) materials and their tuning for nanoscale separations is how specific functional groups influence the competitive adsorption of solvated ions and water at liquid/graphene interfaces. Computation accompanied by experiment shows that OH and COOH exert an influence on water adsorption properties stronger than that of O and H functional groups. The COO– anions, following COOH deprotonation, stabilize Pb(II) through strong electrostatic interactions. This suggests that, among the functional groups under study, COOH offers the best Pb(II) adsorption capacity and the ability to regenerate the sorbent through a pH swing. In line with computation, striking experimental observations revealed that a substantial increase in Pb(II) adsorption occurs with increasing pH. Our findings provide a systematic framework for controlled design and implementation of regenerable C-based sorbents used in separations and desalination.

Background Up to 7.5% of tined-lead removals in patients having sacral neuromodulation (SNM) therapy are associated with a lead breakage. It is still unclear what adverse effects can be caused by unretrieved fragments. The aim of our study was to describe the lead removal technique we have been using for the last 2 years in our centre. Methods We retrospectively enrolled patients who had lead removal between January 2018 and January 2020 using our standardized technique. The novelty of the technique is in the use of the straight stylet, which is available in the quadripolar tined-lead kit. The stylet gives the electrode greater stiffness, reducing interactions with surrounding tissues and probability of damage or breakage during removal. Results In 59 patients (42 women, mean age 57.2 years [range 40–79 years]) the lead was removed using our standardized technique. In 44 of 59 patients, the tined-lead was removed within 2 months from the SNM-test, due to lack of beneficial effects. In 15 patients the electrode was removed because of failure of definitive implantation. Meantime from definitive implantable pulse generator (IPG) implantation to lead removal was 67.9 months. We recorded only 1 case of lead-breakage during removal: a female patient with a non-tined lead fixed on sacral bone, placed 18 years previously using an open technique. Conclusions Lead breakage during removal is not uncommon and adverse effects of retained fragments may occur. Our technique has been safely used for the last 2 years in our centre, with no episodes of lead breakage or retained fragments, except for one non-tined electrode.

Iron oxide nanoparticles have attracted much attention because of their superparamagnetic properties and their potential applications in many fields such as magnetic storage devices, catalysis, sensors, superparamagnetic relaxometry (SPMR), and high‐sensitivity biomolecule magnetic resonance imaging (MRI) for medical diagnosis and therapeutics. In this study, iron oxide nanoparticles (Fe2O3 NPs) have been synthesized using a taranjabin (camelthorn or persian manna) aqueous solution. The synthesized Fe2O3 NPs were identified through powder X‐ray diffraction (PXRD), X‐ray photoelectron spectroscopy (XPS), Fourier transform infrared spectroscopy (FT‐IR), field energy scanning electron microscopy (FESEM), transmission electron microscopy (TEM), energy‐dispersive spectroscopy (EDX), vibrating‐sample magnetometer (VSM) and Raman technics. The results show that the nanoparticles have a hexagonal structure with 20 to 60 nm in size. The cytotoxic effect of the synthesized nanoparticles has been tested upon application against lung cancer cell (A549) lines. It was found that there is no cytotoxic activity at lower concentrations of 200 μg/mL. The ability of the synthesized nanoparticles for lead removal in wastewaters was tested. Results show that highest concentration of adsorbent (50 mg/L) has maximum removal efficiency (96.73 %). So, synthesized Fe2O3 NPs can be a good candidate to use as heavy metals cleaner from contaminated waters., Iron oxide nanoparticles have been synthesized using persian manna in aqueous solution. The nanoparticles have been tested for cytotoxic activity and for their lead removal properties in wastewaters.

In the current study heavy metal removing capability and antioxidant properties of chitosan supplemented diet tested in lead poisoning induced Oreochromis mossambicus in comparison with and standard fish diet. O. mossambicus fishes weighed (20 ± 2gm) were purchased from a local commercial fish pond and acclimated to the laboratory conditions for 10 days. After that fish were dived into four groups, each group received respective feed throughout the experimental period. The fish fed with standard diet exhibited drastic weakening of superoxide dismutase (SOD), catalase (CAT), reduced glutathione (GR), glutathione peroxidase (GPx), ascorbic acid, α- tocopherol and β-carotene and also displayed abnormal histological changes in gills, liver, and intestine. The fish fed with a chitosan supplemented diet for 10 days showed substantial enhancements in antioxidant levels and also normal histological structures of organs in the fish.

Sugarcane bagasse-based activated carbon (AC) was produced via a physical activation method using CO2, to remove lead (Pb) ions from an aqueous solution. The physical and chemical properties of ACs were examined by scanning electron micrograph (SEM), Brunauer–Emmett–Teller (BET) surface area, and Fourier-transform infrared spectroscopy (FTIR) analysis. The effect of both pH and contact time on adsorption was studied via a batch process. Based on the BET results, we have identified that BET surface area and micropore volume decreased at the highest activation temperature, while the intensity of the functional groups increased when the activation temperature was raised. The adsorption isotherms were best fitted with the Langmuir equation, which was used to describe the adsorption process and to examine the adsorption mechanisms of Pb(II) on the AC. The maximum adsorption capacity of Pb(II) was 60.24 mg g−1 with AC850. The adsorption kinetic study closely followed the pseudo-second order (R2 > 0.99). AC has the potential to economically remove metal ions in the purification process of wastewater. AC850 was also utilized in the manufacture and testing of pouch cell supercapacitors to demonstrate the potential of the sugarcane bagasse family of materials in energy storage applications. The devices made with the unmodified, nonoptimized material used for Pb(II) sorption demonstrated high rate and power-energy characteristics (>50% capacitance retention with 10-fold increase in current density, 10 Wh Kg−1 at 2500 W Kg−1, active material mass) but there remains a need for further optimization, particularly the removal of oxygen functionality, to enhance lifetime and specific capacitance. This work demonstrated the potential for sugarcane bagasse carbons across environmental applications.

Данная работа посвящена исследованию возможностей очистки никелевого Ñ Ð»Ð¾Ñ€Ð¸Ð´-сульфатного электролита от свинца и Ñ€Ð°Ð·Ñ€Ð°Ð±Ð¾Ñ‚ÐºÐµÂ Ð¾Ð¿Ñ‚Ð¸Ð¼Ð°Ð»ÑŒÐ½Ñ‹Ñ Ñ€ÐµÐ¶Ð¸Ð¼Ð¾Ð² извлечения. Задачи, которые решались в Ñ Ð¾Ð´ÐµÐ¸ÑÑÐ»ÐµÐ´Ð¾Ð²Ð°Ð½Ð¸Ñ:1) Изучение особенностей способов глубокой очистки Ð½Ð¸ÐºÐµÐ»ÐµÐ²Ñ‹Ñ Ñ€Ð°ÑÑ‚Ð²Ð¾Ñ€Ð¾Ð² от свинца;2) Выявление наиболее Ð¿Ð¾Ð´Ñ Ð¾Ð´ÑÑ‰ÐµÐ³Ð¾ метода для вывода свинца Ð¸Ð·Ñ Ð»Ð¾Ñ€Ð¸Ð´Ð½Ñ‹Ñ ÑÐ»ÐµÐºÑ‚Ñ€Ð¾Ð»Ð¸Ñ‚Ð¾Ð²;3) Исследования физико-Ñ Ð¸Ð¼Ð¸Ñ‡ÐµÑÐºÐ¸Ñ ÑÐ²Ð¾Ð¹ÑÑ‚Ð² и ÐµÐ¼ÐºÐ¾ÑÑ‚Ð½Ñ‹Ñ Ñ Ð°Ñ€Ð°ÐºÑ‚ÐµÑ€Ð¸ÑÑ‚Ð¸ÐºÐ¸Ð¾Ð½Ð¸Ñ‚Ð¾Ð²;4) Проведение сорбционной очистки рабочего раствора;5) Анализ Ð¿Ð¾Ð»ÑƒÑ‡ÐµÐ½Ð½Ñ‹Ñ Ð°Ð½Ð°Ð»Ð¸Ñ‚Ð¸Ñ‡ÐµÑÐºÐ¸Ñ Ð´Ð°Ð½Ð½Ñ‹Ñ ;6) Расчет показателей сорбции и ÑÐ¾Ñ€Ð±Ñ†Ð¸Ð¾Ð½Ð½Ñ‹Ñ ÐºÐ¾Ð»Ð¾Ð½Ð½;Работа проведена в ООО «Институт Гипроникель», где собиралась значительная часть фактического материала (результаты Ð°Ð½Ð°Ð»Ð¸Ñ‚Ð¸Ñ‡ÐµÑÐºÐ¸Ñ Â Ð´Ð°Ð½Ð½Ñ‹Ñ ). Были проведены лабораторные исследования, показывающие возможность реализации сорбционной очистки Ñ Ð»Ð¾Ñ€Ð¸Ð´-сульфатного электролита от свинца до требуемой глубины очистки. Были проведены расчеты, показывающие наглядно, факторы, влияющие на параметры сорбционного процесса.Разработаны рекомендации для проектирования передела сорбции Ð²Â Ñ‚ÐµÑ Ð½Ð¾Ð»Ð¾Ð³Ð¸Ð¸., This work is devoted to the study of the possibilities of purification of nickel chloride-sulfate electrolyte from lead and the development of optimal extraction modes. Tasks that were solved in the course of the study:1) Studying the features of methods for deep purification of nickelsolutions from lead;2) Identification of the most appropriate method for removing lead fromchloride electrolytes;3) Research of physical and chemical properties and capacitivecharacteristics of ion exchangers;4) Carrying out sorption purification of the working solution;5) Analysis of the received analytical data;6) Calculation of sorption and sorption columns;The work was carried out at «Gipronickel Institute» LLC, where a significant part of the factual material (the results of analytical data) was collected. Laboratory studies were carried out showing the possibility of implementing the sorption purification of the chloride-sulphate electrolyte from lead to the required purification depth. Calculations were carried out showing clearly the factors affecting the parameters of the sorption process.Recommendations have been developed for designing the sorption process in technology.

Lead (Pb) exposure can be harmful to public health, especially through drinking water. One of the promising treatment methods for lead contaminated water is the adsorption-filtration method. To ensure the cost-effectiveness of the process, naturally derived adsorbent shall be utilised. In this study, hydroxyapatite particles, Ca10(PO4)6(OH)2 (HAP) derived from waste cockle shell, were incorporated into the outer layer of polysulfone/HAP (PSf/HAP) dual-layer hollow fibre (DLHF) membrane to enhance the removal of lead from the water source due to its hydrophilic nature and excellent adsorption capacity. The PSf/HAP DLHF membranes at different HAP loadings in the outer layer (0, 10, 20, 30 and 40 wt%) were fabricated via the co-extrusion phase inversion technique. The performance of the DLHF membranes was evaluated in terms of pure water flux, permeability and adsorption capacity towards lead. The results indicated that the HAP was successfully incorporated into the outer layer of the membrane, as visibly confirmed by microscopic analysis. The trend was towards an increase in pure water flux, permeability and lead adsorption capacity as the HAP loading increased to the optimum loading of 30 wt%. The optimized DLHF membrane displayed a reduced water contact angle by 95%, indicating its improved surface hydrophilicity, which positively affects the pure water flux and permeability of the membrane. Furthermore, the DLHF membrane possessed the highest lead adsorption capacity, 141.2 mg/g. The development of a hybrid inorganic–organic DLHF membrane via the incorporation of the naturally derived HAP in the outer layer is a cost-effective approach to treat lead contaminated water.

Centimeter-scale composite biochar-alginate gel beads (MoS2B/CaCO3/Alg) were designed for the adsorption of Pb(II) in water using MoS2 modified biochar as the filler, alginate as the matrix, and CaCO3 as the active additive component. The composite gel beads were characterized using scanning electron microscope (SEM), X-ray photoelectron spectroscopy (XPS), Fourier transform infrared (FTIR), X-ray diffraction (XRD), and other techniques. MoS2B/CaCO3/Alg showed excellent adsorption capacity over a wide range of pH 4–7. The maximum adsorption capacities obtained using the Langmuir model were 769.2, 833.3, and 909.1 mg g−1 at 10, 25 and 40 °C, respectively. At a dosing rate of 0.4 g L−1, MoS2B/CaCO3/Alg was able to reduce the Pb(II) concentration to below 0.05 ppm in complex simulated lead battery wastewater. After 10 repeated cycles, MoS2B/CaCO3/Alg maintained a high removal rate of 98.4 %. This spherical adsorbent is simple to prepare and easy to recover, has an ultra-high adsorption capacity, and is mechanically stable and resistant to interference, thus it is expected to be suitable for application in industrial wastewater treatment.

Capacitive deionization (CDI) is a promising and rapidly growing technology for water treatment and the electrode materials play a key role in improving CDI performance. In this study, high surface area activated carbon was prepared from chicken feather (CF) bio-waste through pyrolysis and KOH activation; the KOH:CF ratio (R) and activation temperature (Ta) were variable parameters. The material was characterized by using the Brunauer, Emmett and Teller (BET) method, Fourier transform infrared (FTIR) spectroscopy and scanning electron microscopy (SEM). The lead (Pb2+) removal test was performed with a CDI cell containing the fabricated carbon electrode and 100 mg L−1 Pb(NO3)2 solution; the sample prepared with the ratio R of 1:1 and Ta = 800 °C exhibited higher Pb2+ removal efficiency of 81% and electro sorption capacity of 4.1 mg g−1 at the electrode potential 1.2 V and flow rate 5 mL min−1. Therefore, CF-derived carbon is considered as a promising CDI electrode material for removal of heavy metals from waste water.

Microbial agents have promise for the bioremediation of Pb(II)-polluted environments and wastewater, the biodecontamination of foods, and the alleviation of toxicity in living organisms. The dairy bacterium Propionibacterium freudenreichii is poorly able to remove Pb(II) from aqueous solution at 25 ppm, ranging from 0 to 10% of initial concentration. Here, we report on an original strong enhancement of this activity (ranging from 75% to 93%, p < 0.01) following the addition of a polysorbate detergent (Tween® 80) during or either shortly after the growth of a P. freudenreichii culture. We evaluated the optimal Tween® 80 concentration for pretreatment conditions, documented the role of other detergents, and explored the possible mechanisms involved. Our results reveal a novel, environmentally friendly, low-cost pretreatment procedure for enhancing the selective removal of lead from water by probiotic-documented bacteria., Les agents microbiens sont prometteurs pour la biorestauration des environnements et des eaux usées pollués par le Pb(II), la biodecontamination des aliments et l’atténuation de la toxicité dans les organismes vivants. La bactérie laitière bioremediation; lead removal; Propionibacterium freudenreichii; polysorbate 80; Tween 80est mal en mesure d’éliminer le Pb(II) de la solution aqueuse à 25 ppm, allant de 0 à 10 % de la concentration initiale. Ici, nous faisons état d’une forte augmentation originale de cette activité (allant de 75 % à 93 %, p < 0,01) après l’ajout d’un détergent polysorbate (Tween® 80) pendant ou peu après la croissance d’une culture de P. freudenreichii. Nous avons évalué la concentration optimale de Tween® 80 pour les conditions de prétraitement, documenté le rôle d’autres détergents et exploré les mécanismes possibles. Nos résultats révèlent une nouvelle procédure de prétraitement écologique et peu coûteuse pour améliorer l’élimination sélective du plomb de l’eau par des bactéries documentées par des probiotiques.

Four naturally occurring zeolites were examined to verify their assignments as chabazites AZLB-Ca and AZLB-Na (Bowie, Arizona) and clinoptilolites NM-Ca (Winston, New Mexico) and NV-Na (Ash Meadows, Nevada). Based on powder X-ray diffraction, NM-Ca was discovered to be mostly quartz with some clinoptilolite residues. Treatment with concentrated HCl (12.1 M) acid resulted in AZLB-Ca and AZLB-Na, the chabazite-like species, becoming amorphous, as confirmed by powder X-ray diffraction. In contrast, NM-Ca and NV-Na, which are clinoptilolite-like species, withstood boiling in concentrated HCl acid. This treatment removes calcium, magnesium, sodium, potassium, aluminum, and iron atoms or ions from the framework while leaving the silicon framework intact as confirmed via X-ray fluorescence and diffraction. SEM images on calcined and HCl treated NV-Na were obtained. BET surface area analysis confirmed an increase in surface area for the two zeolites after treatment, NM-Ca 20.0(1) to 111(4) m2/g and NV-Na 19.0(4) to 158(7) m2/g. 29Si and 27Al MAS NMR were performed on the natural and treated NV-Na zeolite, and the data for the natural NV-Na zeolite suggested a Si:Al ratio of 4.33 similar to that determined by X-ray fluorescence of 4.55. Removal of lead ions from solution decreased from the native NM-Ca, 0.27(14), NV-Na, 1.50(17) meq/g compared to the modified zeolites, 30 min HCl treated NM-Ca 0.06(9) and NV-Na, 0.41(23) meq/g, and also decreased upon K+ ion pretreatment in the HCl modified zeolites.

This work presents the results obtained in the design and manufacture of a simple, economic and ecological filter based on Sargassum spp. (Sspp), consisting of the species S. natans and S. fluitans, for the elimination of organic and inorganic toxic substances. The main objective is to make use of Sspp, as the massive amounts of this alga arriving at the Mexican Caribbean coast have caused serious problems over recent years. The toxic substances treated were organic dyes (methyl blue, methyl orange and methyl red) and the metal ion, lead (II). To obtain optimal removal conditions, grinding of the Sspp used, its mass and humidity were evaluated. In the design of the filter the area, flow rate and the number of layers were evaluated. Removal rates of almost 100%, 65% and 25% were obtained for methylene blue, methyl red and methyl orange respectively, and in the case of lead (II), values up to 95% were obtained. After the tests, the Sspp was characterized, using Fourier Transform Infrared (FTIR) spectroscopy and scanning electron microscopy, showing the presence of the dyes and the ionic species. These results demonstrate the efficiency of the dynamic Sspp-based filtration system proposed, which can be industrially scaled for the treatment of water contaminated with these kinds of substances.

National Institute of Technology Durgapur, Durgapur-713 209, West Bengal, India E-mail: san.mondal@gmail.com Manuscript received online 01 June 2020, revised and accepted 17 October 2020 In this work, iron oxide magnetic nanoparticles (Fe3O4) have been synthesized using pomegranate peel extract, via green synthesis route, to remove heavy metal lead (II) from aqueous medium. Iron powder has been used as precursor agent and pomegranate peel extract has been used as reducing agent. The reaction process, i.e. co-precipitation, is simple, of low cost and eco-friendly. Synthesized adsorbent i.e. nanoparticles, were first characterized by XRD to know the crystalline structure and phase. Also, SEM analysis was carried out to know the surface morphology of the adsorbent and the surface area of the nano particles were estimated using BET surface area analyzer. The average surface area of the nanoparticles is 173.38 m²/g. Average particle size is 35 nm as found in DLS analysis. The adsorption of Pb2+ on the surface of nano adsorbent follows Pseudo second order reaction model and Langmuir isotherm model. The maximum adsorption capacity of nano adsorbent is 142.999 mg/g. Maximum removal efficiency was observed to be 97.95% at pH 6.

Though recycling of waste paper is widely practiced but usually it is downgraded to lower valued recycled waste paper. Based on this concern, we report the development of novel NaOH/urethane aqueous system for extraction of microfibrillated cellulose from waste paper. The purity of so obtained microfibrillated cellulose (MFC) was evaluated by morphological tests using scanning electron microscopy (SEM) and transmission electron microscopy (TEM) and by evaluation of physicochemical properties using Fourier-transform infrared (FTIR) spectroscopy, X-ray diffraction (XRD), differential scanning calorimetry (DSC), and thermogravimetric analysis (TGA). Morphologies of MFC studied by SEM and TEM showed that the size of purified cellulose fibrils reduced when compared to that of waste paper but fibrils are cleaner and smoother due to the removal of talc and lignin. XRD analysis revealed that MFC exhibits good crystallinity. The utility of sulfonated and pristine microfibrillar cellulose in removal of lead from contaminated water is also reported. Our results show that renewable, sustainable, cheap, and waste biomass like waste paper can be used for producing valuable second-generation high-value products.

Lead is a toxic metal and its removal from industrial effluents is important. This can be done in several ways including ion dissolved air flotation (DAF). The advantages of the latter are multiple, among them speed, efficiency, low cost and space requirement. Tests were carried out with an aqueous synthetic wastewater of lead nitrate simulating the effluent of a producer of batteries. Xanthate was used as collector, a widely applied approach in ore processing. The variables studied were the size of the hydrocarbon chain of xanthate, xanthate concentration, pH, contact time, and foaming concentration. Quantification of residual lead was obtained by atomic adsorption. The proposed method revealed that dissolved air flotation is an efficient technique for the removal of lead ions, like the technique at the present is successful used in ore separation. It was observed that the pH and the amount of foaming did not have an effect. However, a solution of 20 mg L-1 of Pb could be reduced to 0.65 mg L-1, corresponding to a removal of 96.8% of the initial concentration.

Recently the low-cost adsorbent for heavy metals removal such as Lead in recent years has been noticed by researchers. In this study, lead removal by clinoptilolite has been investigated. Non-continuous lead absorption from aqueous solution was carried out by using clinoptilolite. The zeolite characteristics were analyzed with SEM and XRD. The effect of pH variables (1, 3, 5, 7, 10), contact time (15, 30, 45, 60, 90 min), clinoptilolite adsorbent dosage (1, 3, 5, 7, 10 g) and lead concentrations (10, 20, 40, 50, 60, 70, 80 & 100 mg/L) were studied on lead removal efficiency and adsorption isotherms and kinetics in constant temperature and stirrer speed of 250 rpm. According to the results, optimum conditions of lead removal by natural zeolite were pH of 8, adsorbent dosage of 5 g/L and contact time of 45 min., the highest removal efficiency of 89.6 achieved. By increasing metal concentration, the amount of removed lead was decreased while absorption capacity increased. Of the two studied models, the Langmuir isotherm had better conformity for lead adsorption (R2=0.99) than other isotherms. Also the pseudo second order kinetics model had better conformity with achieved data than other models. Results of this study indicated that natural clinoptilolite zeolite can be considered as an efficient and cost effective adsorbent for lead removal from aqueous solutions.

Guidelines for the implantation of cardiac implantable electronic devices (CIEDs) have evolved since publication of the initial ACC/AHA pacemaker guidelines in 1984 [ 1 ]. CIEDs have evolved to include novel forms of cardiac pacing, the development of implantable cardioverter defibrillators (ICDs) and the introduction of devices for long term monitoring of heart rhythm and other physiologic parameters. In view of the increasing complexity of both devices and patients, practice guidelines, by necessity, have become increasingly specific. In 2018, the ACC/AHA/HRS published Guidelines on the Evaluation and Management of Patients with Bradycardia and Cardiac Conduction Delay [ 2 ], which were specific recommendations for patients >18 years of age. This age-specific threshold was established in view of the differing indications for CIEDs in young patients as well as size-specific technology factors. Therefore, the following document was developed to update and further delineate indications for the use and management of CIEDs in pediatric patients, defined as ≤21 years of age, with recognition that there is often overlap in the care of patents between 18 and 21 years of age. This document is an abbreviated expert consensus statement (ECS) intended to focus primarily on the indications for CIEDs in the setting of specific disease/diagnostic categories. This document will also provide guidance regarding the management of lead systems and follow-up evaluation for pediatric patients with CIEDs. The recommendations are presented in an abbreviated modular format, with each section including the complete table of recommendations along with a brief synopsis of supportive text and select references to provide some context for the recommendations. This document is not intended to provide an exhaustive discussion of the basis for each of the recommendations, which are further addressed in the comprehensive PACES-CIED document [ 3 ], with further data easily accessible in electronic searches or textbooks.

Cathode ray tube (CRT) monitors are electronic equipment mainly made of glass, polymers and metals. These devices became obsolete because of emerging technologies such as LCD, LED and plasma; thus generating a huge stockpile of e-waste worldwide. In this CRT study, a natural leaching simulation (NBR10005) was performed to determine the toxicity of this e-waste. The standard NBR 10005 procedure was performed for 7 different monitors. The results show all samples are hazardous according to local environmental law (NBR 10004) due to lead leaching. The CRT panel is lead free, while the CRT funnel and neck have about 20% of lead oxide in their composition. Moreover, six optimum thermal lead removal procedures were performed and the NBR 10005 procedure was repeated. The results reveal that vacuum atmosphere and the addition of 5% carbon graphite as reducing agent are optimum conditions to turn the CRT into a non-hazardous waste. Three out of six parameters were capable of satisfactorily removing the lead and turning the post-procedure waste lead-leaching safe.

Lead is a heavy metal which has many applications in different industries. Due to toxicity of lead, discharging industrial effluents which contain these ions will bring irreversible risks to the environment and living ecosystems. The objective of this study is to analyse the use of Eucalyptus sawdust as a cheap adsorbent for lead removal from effluent. The experiments were conducted in batch system and the effect of pH, the amount of adsorbent, contact time and the initial concentration of lead were examined. Noticing the results, the maximum efficiency of lead adsorption is 96.25% which was obtained in pH of 7 and contact time of 30 minutes and 10 g/L of adsorbent. By increasing the initial concentration of lead, the adsorbed metal and removal percentage also increased. Achieved data from this study indicated a good compatibility with Langmuir adsorption isotherm. Kinetic analysis indicated that lead adsorption matches with the second-order kinetic adsorption model (R2=0.998). Noticing the high efficiency of lead removal by Eucalyptus sawdust, this method could be used as an effective and cheap adsorbent for lead removal.

In this work, hydrozincite and Zn/Al-CO3 2− hydrotalcite supported on silica aerogel were prepared via a simple and economical process and used as adsorbents for Pb(II) removal. The supported hydrozincite and Zn/Al-CO3 2− hydrotalcite possess ultra-thin thickness, high surface area, and weak crystallinity. In the batch Pb(II) adsorption experiments, the adsorbents with higher Zn(II) contents showed higher Pb(II) adsorption capacities, and the adsorption data fitted well with the Langmuir isotherm model and pseudo-second-order kinetic model, indicating a mechanism of surface chemisorption. The adsorption capacities calculated based Langmuir isotherm model are 684.9 mg/g and 555.6 mg/g for the supported hydrozincite and Zn/Al-CO3 2− hydrotalcite, respectively, higher than the adsorption capacities of other hydrotalcite-based adsorbents and most of other inorganic adsorbents reported previously. The XRD diffraction peaks of hydrozincite and Zn/Al-CO3 2− hydrotalcite disappeared after the adsorption, and the Pb(II) species were uniformly dispersed in the adsorbents in form of Pb3(CO3)2(OH)2 proven by TEM, EDS mapping and XRD analysis, demonstrating the nature of the adsorption is the precipitation conversion of hydrozincite or Zn/Al-CO3 2− hydrotalcite into Pb3(CO3)2(OH)2. These results demonstrate the synergic Pb(II) removal effect of the CO3 2− and OH− derived from hydrozincite and Zn/Al-CO3 2− hydrotalcite together with their ultra-thin thickness and high surface area contribute the excellent properties of the adsorbents. Electronic supplementary material The online version of this article (10.1186/s11671-017-2323-2) contains supplementary material, which is available to authorized users.

Lead (Pb(II)) pollution in water poses a serious threat to human health in many parts of the world. In the past decades, research has been aimed at developing efficient and cost-effective methods to address the problem. In this study, dimethyl sulfoxide (DMSO) and potassium acetate (K-Ac) intercalated kaolinite complexes were synthesized and subsequently utilized for Pb(II) removal from water. The intercalation of kaolinite with DMSO was found to be useful for expanding the interlayer space of the clay mineral from 0.72 to 1.12 nm. Kaolinite intercalation with K-Ac (KDK) increased the interlayer space from 1.12 to 1.43 nm. The surface area of KDK was found to be more than threefold higher as compared to natural kaolinite (NK). Batch experimental results revealed that the maximum Pb(II) uptake capacity of KDK was 46.45 mg g−1 which was higher than the capacity of NK (15.52 mg g−1). Reusability studies showed that KDK could be reused for 5 cycles without substantially losing its adsorption capacity. Furthermore, fixed-bed column tests confirmed the suitability of KDK in continuous mode for Pb(II) removal. Successful application of intercalated kaolinite for Pb(II) adsorption in batch and column modes suggests its application in water treatment (especially removal of divalent metals). Electronic supplementary material The online version of this article (10.1007/s11356-019-06845-w) contains supplementary material, which is available to authorized users.

In this study, we present a low-cost and simple method to treat spent lead–acid battery wastewater using quicklime and slaked lime. The sulfate and lead were successfully removed using the precipitation method. The structure of quicklime, slaked lime, and resultant residues were measured by X-ray diffraction. The obtained results show that the sulfate removal efficiencies were more than 97% for both quicklime and slaked lime and the lead removal efficiencies were 49% for quicklime and 53% for slaked lime in a non-carbonation process. After the carbonation step, the sulfate removal efficiencies were slightly decreased but the lead removal efficiencies were 68.4% for quicklime and 69.3% for slaked lime which were significantly increased compared with the non-carbonation process. This result suggested that quicklime, slaked lime, and carbon dioxide can be a potential candidate for the removal of sulfate and lead from industrial wastewater treatment.

Submitted by JOSIANE SANTOS DE OLIVEIRA (josianeso) on 2019-05-30T15:56:23Z No. of bitstreams: 1 Gustavo Luís Benini_.pdf: 4580878 bytes, checksum: 7a6cbb4b166cd3764b54b7912841d92a (MD5) Made available in DSpace on 2019-05-30T15:56:23Z (GMT). No. of bitstreams: 1 Gustavo Luís Benini_.pdf: 4580878 bytes, checksum: 7a6cbb4b166cd3764b54b7912841d92a (MD5) Previous issue date: 2019-02-28 CAPES - Coordenação de Aperfeiçoamento de Pessoal de Nível Superior A remoção de carga orgânica por meio de reatores UASB é um processo consolidado no tratamento de esgoto sanitário. Os critérios técnicos operacionais e dimensionais deste tipo de reator já estão estabelecidos na literatura, e são de amplo conhecimento no saneamento ambiental. Entretanto, o fluxo de metais potencialmente tóxicos no processo ainda necessita de maiores estudos. Entre os aspectos que ainda precisam ser estudados está o entendimento do fluxo de massa de chumbo quando se processa o tratamento de esgoto sanitário em reator UASB. O objetivo deste trabalho foi avaliar o fluxo de massa de chumbo em um reator UASB de 830L, operou-se com temperatura do afluente de 36,03 °C e TDH de 12,88 horas. O reator foi alimentado por com esgoto acrescido de Pb(NO3)2, de forma a liberar o cátion Pb2+ em solução. A operação do reator piloto ocorreu em um período de 16 semanas, divididos em 4 etapas: (1) operação preliminar sem chumbo, por 4 semanas; (2) Verificação do acúmulo de chumbo no lodo (Concentração afluente de 1mg Pb2+/L), por 5 semanas; (3) Influência de diferentes concentrações de chumbo (Concentração afluente de 1mg Pb2+/L, 3mg Pb2+/L e 5mg Pb2+/L); por 3 semanas e (4) nova operação sem adição de chumbo por 6 semanas. Ao longo deste período foi avaliada a qualidade do afluente e efluente, as características do lodo anaeróbio quanto a presença de chumbo, assim como o volume e qualidade do biogás produzido. Os resultados apontam para um acúmulo de chumbo no lodo atingindo a concentração de chumbo de 1933,5 mg/kg, diminuindo a capacidade de remoção de chumbo do afluente de 100% para 9%, incluindo possibilidade de acréscimo de chumbo na saída de efluente. Observou-se ainda uma tendência de diminuição de produção de biogás relacionada com o acúmulo de chumbo no lodo. The removal of organic load by anaerobic digestion in UASB reactors is a consolidated process in the sanitary sewage treatment. The operational and dimensional technical criteria of this type of reactor are well established in the literature and are widely known in environmental sanitation. However, the flow of potentially toxic metals in the process still requires further studies. The aim of this work was to evaluate the mass flow of Lead in a 830L UASB reactor, operated with affluent temperature of 36.03 °C and HRT of 12.88 hours. The reactor was fed with sewage plus Pb(NO3)2, in order to release the Pb2+ cation in solution. The operation of the pilot reactor occurred in a period of 16 weeks, divided in 4 steps: (1) preliminary operation without lead, for 4 weeks; (2) Verification of lead accumulation in the sludge (1mg Pb2+ /L affluent concentration), for 5 weeks; (3) Influence of different concentrations of lead (affluent concentration of 1mg Pb2+/L, 3mg Pb2+/L and 5mg Pb2+/L); for 3 weeks and (4) a new operation without lead addition for 6 weeks. During this period, the quality of the affluent and effluent, the characteristics of the anaerobic sludge including the accumulation of lead, as well as the volume and quality of the biogas produced were evaluated. The results point to an accumulation of Lead in the sludge reaching the concentration of lead of 1933.5 mg/kg, decreasing the lead removal capacity from 100% to 9%, including the possibility of adding lead at the effluent outlet. There was also a trend of decreasing biogas production related to the accumulation of lead in the sludge.

In this study, two types of modified cassava starch samples (MCS and MWS) prepared from commercially available native cassava starch (NCS) and native cassava starch extracted using the wet method (NWS) were investigated for the removal of Pb(II) ions from aqueous solutions. MCS and MWS samples were synthesized under acidic conditions using Pluronic 123 as the structure-directing agent and tetraethylorthosilicate (TEOS) as the chemical modifying agent. Modified starch samples were characterized using Fourier transform infrared (FTIR) spectroscopy, thermogravimetric analysis (TGA), X-ray Diffraction (XRD), and a nitrogen (N2) gas adsorption–desorption analyser. MCS and MWS showed enhanced thermal stabilities upon acid hydrolysis and chemical modification. The effects of contact time and initial Pb(II) concentration were studied through batch adsorption experiments. Adsorption kinetics followed the pseudo-second-order kinetic model. The equilibrium adsorption data were analysed and compared by the Langmuir and Freundlich adsorption models. The coefficient correlation (R2) was employed as a measure of the fit. The Langmuir model fitted well with equilibrium adsorption data, giving a maximum Pb(II) adsorption capacity of 370.37 and 294.12 mg/g for MWS and MCS, respectively. Modified samples exhibited a higher desorption efficiency of over 97%. This study demonstrated that modified starch could be utilized for Pb(II) removal from industrial wastewater.

A novel carbonaceous adsorbent was prepared from sulfur-impregnated heavy oil ash via pyrolysis using potassium sulfide (K2S) solution, and its ability to remove lead (Pb2+) from aqueous solutions was examined. It was compared with an adsorbent synthesized by conventional pyrolysis using potassium hydroxide (KOH) solution. Specifically, the raw ash was immersed in 1 M K2S solution or 1 M KOH solution for 1 day and subsequently heated at 100–1000 °C in a nitrogen (N2) atmosphere. After heating for 1 h, the solid was naturally cooled in N2 atmosphere, and subsequently washed and dried to yield the product. Regardless of the pyrolysis temperature, the product generated using K2S (Product-K2S) has a higher sulfur content than that obtained using KOH (Product-KOH). Moreover, Product-K2S has a higher lead removal ability than Product-KOH, whereas the specific surface area of the former is smaller than that of the latter. Product-K2S obtained at 300 °C (Product-K2S-300) achieves the highest lead adsorption and a high selective lead removal from a ternary Pb2+–Cu2+–Zn2+ solution. The equilibrium capacity of Product-K2S-300 was found to fit the Langmuir model better than the Freundlich model, and its calculated maximum adsorption capacity is 0.54 mmol/g. From the ternary Pb2+–Cu2+–Zn2+ solution, the order of adsorption by Product-K2S-300 is Pb2+ > Cu2+ > Zn2+, and the removal of Pb2+ and Cu2+ increases as the pH of the solution increases.

Introduction: Over the past couple of decades, the use of cardiac implantable electronic devices (CIEDs) has increased significantly. Because of that and because of increased life expectancy of patients, this has led to an increase in the number of the device and lead complications. Consequently, there is a growing need to perform lead removal. Today, lead removal is a specialized procedure with well-defined indications. Indication for lead removal can be infection (infective endocarditis, pocket infection, pocket erosion, bacteremia), lead-related (fracture, insulation defect, dislocation-if the lead cannot be repositioned, dysfunction-for reasons other than lead fracture and insulation defect, CIED upgrade/ need for additional lead(s), perforation) and chronic pain due to a periosteal reaction1. Lead removal can be explantation (removal of leads with a dwell time of less than 1 year and using simple traction), extraction (removal of leads with a dwell time of more than 1 year or with the use of specialized equipment (locking stylets, snares, cutting tools, telescoping and laser sheats) regardless of implant time) and cardiothoracic surgical procedure. Patients and Methods: We retrospectively analyzed the characteristics, types of devices, and indications for lead removal in 70 patients at University Hospital Centre Zagreb between January 2014 and July 2019. Results: Average patient age was 67.6 years and most patients were male (74.3%). 78.6% of patients were on anticoagulation or antiplatelet therapy, and 50% had chronic renal failure or diabetes mellitus. Two most common indications for lead removal were lead dislocation (28 patients) and pocket infection/ erosion (20 patients). Average lead dwelling time was 27.4 months. 38 explantations, 30 extractions, and 2 surgical removals were performed. Total of 99 leads was removed, 1.28 per procedure. Conclusion: The procedure was successful in all patients. There was no recurrence of infection after infected device extraction. Besides 2 cases of pericardial effusion (which were not hemodynamically significant), no other major complication (cardiac tamponade, cardiac avulsion, SVC tear, death) were observed. LITE RATURE 1. Bongiorni MG, Burri H, Deharo JC, Starck C, Kennergren C, Saghy L, et al; ESC Scientific Document Group.2018 EHRA expert consensus statement on lead extraction: recommendations on definitions, endpoints, research trial design, and data collection requirements for clinical scientific studies and registries: endorsed by APHRS/HRS/LAHRS. Europace. 2018 Jul 1;20(7):1217. https://doi.org/10.1093/europace/euy050 Arrhythmias and Electrophysiology Extended Abstract

Clays are known to have promising adsorbing characteristics, and are used as feed additives to overcome the negative effects of mycotoxicosis in livestock farming. Modification of clay minerals by heat treatment, also called calcination, can alter their adsorption characteristics. Little information, however, is available on the effect of calcination with respect to mycotoxin binding. The purpose of this study was to characterize a Tunisian clay before and after calcination (at 550 &deg, C), and to investigate the effectiveness of the thermal treatment of this clay on its aflatoxin B1 (AFB1), G1 (AFG1), B2 (AFB2), G2 (AFG2), and zearalenone (ZEN) adsorption capacity. Firstly, the purified clay (CP) and calcined clay (CC) were characterized with X-ray Fluorescence (XRF), X-ray Diffraction (XRD), Fourier transform infrared spectroscopy (FTIR-IR), cation exchange capacity (CEC), specific surface area (SBET), and point of zero charge (pHPZC) measurements. Secondly, an in vitro model that simulated the pH conditions of the monogastric gastrointestinal tract was used to evaluate the binding efficiency of the tested clays when artificially mixed with aflatoxins and zearalenone. The tested clay consisted mainly of smectite and illite. Purified and calcined clay had similar chemical compositions. After heat treatment, however, some changes in the mineralogical and textural properties were observed. The calcination decreased the cation exchange capacity and the specific surface, whereas the pore size was increased. Both purified and calcined clay had a binding efficacy of over 90% for AFB1 under simulated poultry GI tract conditions. Heat treatment of the clay increased the adsorption of AFB2, AFG1, and AFG2 related to the increase in pore size of the clay by the calcination process. ZEN adsorption also increased by calcination, albeit to a more stable level at pH 3 rather than at pH 7. In conclusion, calcination of clay minerals enhanced the adsorption of aflatoxins and mostly of AFG1 and AFG2 at neutral pH of the gastrointestinal tract, and thus are associated with protection against the toxic effects of aflatoxins.

This work studies the effect of microwaves in the synthesis of carbon adsorbents using pecan nutshell biomass as a precursor in a hybrid multimode microwave cavity avoiding the utilization of chemical activation or susceptors. The dielectric properties were calculated using the cavity perturbation method, and the power distribution of the electromagnetic field inside cavity was obtained by COMSOL Multiphysics. S-350-MW was obtained using at 350 °C and 200 W and it was characterized using elemental analysis, potentiometric titration, FT-IR and nitrogen adsorption isotherms at −196 °C. The adsorption of Pb(II), in single and binary solutions with Cu(II), Cd(II) and Zn(II) in batch systems indicate that the removal of Pb(II) is affected in the presence of Cu(II) due to the competition of these ions as a result of their similarities such as Pauling electronegativity. Finally, the removal of Pb(II) in continuous systems using packed bed columns showed the pH has the most significant effect according to the variance analysis. The finding highlighted the importance of the acidic functional groups in the performance of carbonaceous adsorbents for the removal of Pb(II). Results of this study contribute to the understandings and application of a hybrid heating system and establish the basis of the role of heating processes in the preparation of carbonaceous adsorbents using microwaves. The Pb(II) removal efficiency achieved in this study is significantly higher than the values reported for carbons prepared by using microwave heating which employs susceptors and/or chemical agents reported in literature, demonstrating that it is possible to obtain effective carbon absorbents for the removal of Pb(II) without the use of any additional susceptors or chemical activation., This work was supported by CONACyT under the grant (389535)

International Conference Interdisciplinarity in Engineering (12th, 2018, Tirgu Mures, Romania), We are thankful to the Ministry of Education, Science and Technological Development of the Republic of Serbia, which has been financing projects T3R 4013, ON172018 and TR 33039. The results are a part of T34013R and ON172018.

Lead, a highly toxic element, is frequently present in various solid wastes as well as in industrial effluents. Sorption with a low cost sorbent is a simple way of Pb removal from liquid streams, but stabilization of spent sorbent has to be ensured in order to prevent Pb leaching out and possible environmental contamination. In previous research, ceramic sorbent, generated as waste product in brick industry, was tested as sorbent and proved high sorption capacity for lead. Lead was sorbed partially as hydrocerussite and partially as adsorbed surface layer. The Pb leaching from sorbent was very high and thus further immobilization of sorbent was necessary. Lead, as well as other heavy metals, is known as retarder of the hydration process of Ordinary Portland Cement (OPC), used for the immobilization. In this paper, influence of sorbed Pb and PbO, as reference compound, on cement hydration was studied by calorimetry, thermogravimetry and Magic Angle Spinning Nuclear Magnetic Resonance Spectroscopy (MAS NMR). The sorbed lead was found to be less detrimental to hydration retardation due to the lower solubility of precipitated hydrocerussite in basic environment compared to PbO, which forms plumbate anion.

Gelişen teknoloji, insanların tüketim alışkanlıklarını değiştirerek, endüstrinin farklı üretim potansiyelini ortaya çıkarmıştır. Sanayileşmenin artması, hammadde ve ürün çeşitliliğini etkilemiştir. Üretimden sonra fabrikalarda çeşitli atıklar açığa çıkar ve bu zehirli maddeler çevreye bırakılır. Deşarj edilen atıklar çevrede biriktiklerinde oldukça zehirlidir. Bu atıklar yapısında ağır metalleri de içerirler. Ağır metallerden biri kurşun (II) iyonudur. Son yıllarda sanayilerden kaynaklanan atıksuların çeşitliliği ve miktarı artmaktadır. Atıksulardaki bu çeşitlilik, atıkların bertarafında kullanılan klasik arıtma yöntemlerini yetersiz kılmaktadır. Ayrıca bu arıtma yöntemleri iyileştirme maliyetlerini artırabilmektedir. Değerli metallerin geri kazanımı, farklı arıtma metotlarının önemini artırmaktadır. Araştırmalar, ağır metalleri uzaklaştırmak için birçok yöntemin kullanıldığını göstermiştir. Bu çalışmada, sentetik ve akü sanayi atıksularından kurşun (II) iyonlarının biyosorpsiyonu için Kapya biberi (Capsicum annuum L.) çekirdeklerinin kullanımı araştırılmıştır. Çalışmalarda Kapya biber çekirdeklerine ön kimyasal işlem uygulanmamıştır. Kurşun, en çok batarya endüstrisinde kullanılan bir ağır metaldir. Bu yüzden çalışmalarda akü sanayi atıksuyu seçilmiştir. Deneysel çalışmalarda kullanılan biyokütle boyutu 125-250 μm aralığındadır. Yapılan deneylerde optimum pH değerinin sentetik atıksu için 5 olduğu bulunmuştur. Çalışmalar, 25°C sabit sıcaklıkta ve başlangıç kurşun konsantrasyonu genellikle ortalama 100 mg/L olacak şekilde gerçekleştirilmiştir. Deneysel çalışmalarda adsorbent dozajı 1,2 g/L olarak belirlenmiştir. Biyosorpsiyon süreci için detaylı kinetik ve izoterm çalışmaları gerçekleştirilmiştir. İzoterm analizlerinde Langmuir, Freundlich ve Temkin izoterm modelleri kullanılmıştır. Bu çalışmada değerlendirilen kinetik modeller ise yalancı birinci derece, yalancı ikinci derece ve Weber Morris modelleridir. Çalışmalar sonunda biyosorpsiyonun yalancı 2. derece kinetik modeli ve Langmuir izoterm modeli ile açıklanabileceği belirlenmiştir. Langmuir izoterm modeline göre maksimum tutma kapasitesi 29,67 mg/g olarak bulunmuştur. Deneysel çalışmalar sonucunda sentetik atıksu ile yapılan çalışmalarda, 5,4 g/L adsorbent dozajı ile ortalama 100 mg/L kurşun içeren sentetik atıksuda 90 dakika sonunda maksimum % 94 lük bir giderim verimine ulaşılmıştır. Gerçek atıksu kullanılarak yapılan adsorbent dozajı deneyinde 10 g/L ve 8 g/L miktarda biyokütle kullanımı sonunda sırasıyla % 37,5 ve % 71 lik giderim verimine ulaşılmıştır. Developing technology has revealed the different production potential of the industry by changing the consumption habits of people. Increasing in industrialization affected the variety of raw materials and products. Various wastes emerge after manufacturing processes in factories and these toxic wastes are released into environment. The discharged wastes are quite toxic when they accumulate in environment. These wastes contain heavy metals in their structure. One of the heavy metals is lead (II) ion. The variety and quantity of wastes originating from industries are increasing in recent years. Classical treatment methods which used for disposal of wastes are inadequate due to this variety of wastewaters. Also, these treatment methods can increase reclamation costs. Recovery of precious metals raises the importance of different treatment methods. Studies have showed that a lot of methods could be used to remove heavy metals. In this study, the use of Capia pepper (Capsicum annuum L.) seeds for biosorption of lead (II) ions from synthetic and storage battery industry wastewaters has been investigated. The biomass was used without pretreatment by chemicals. Lead is a heavy metal mostly used in storage battery industries. Therefore, storage battery industry wastewater was choosen. The size of the biomass used in the studies was in the range of 125-250 µm. It was found in the experiments that the optimum pH value for synthetic wastewater was 5. Studies were conducted at a constant temperature of 25°C. The average initial lead concentration in synthetic wastewater was 100 mg/L, generally. In experimental studies, the adsorbent dosage was determined as 1.2 g/L. Kinetic and isotherm studies for biosorption process were carried out in detail. Langmuir, Freundlich and Temkin isotherm models were used in isotherm analyses. The kinetic models evaluated in this study are pseudo first order, pseudo second order and Weber Morris models. At the end of the studies, it was determined that the biosorption could be explained with pseudo second order kinetic model and Langmuir isotherm model. Maximum sorption capacity was found to be 29.67 mg/g according to Langmuir isotherm model. At the end of the studies conducted with synthetic wastewaters, a maximum removal efficiency of 94% was obtained by using 5.4 g/L biomass with synthetic wastewater containing approximately 100 mg Pb2+/L at the end of 90 minutes treatment. In the study of adsorbent dose carried out with real wastewater, removal efficiencies of 37.5% and 71% were obtained by using 10 g/L and 8 g/L biomass, respectively. 101

Lead is one of the most toxic heavy metals that can create a severe risk to water ecosystem health. Zero-valent iron is an effective material for Pb2+ removal treatments. In particular, nanoscopic zero-valent iron (nZVI) particles are characterized by high reaction rates; nevertheless, their utilization in water and groundwater remediation techniques requires further investigations. Indeed, it is necessary to define effective methods able to avoid the drawbacks due to the aggregation tendency of nanoparticles and their potential uncontrolled transport in groundwater. In this work, nZVI was supported on magnesium oxide grains (MgO_nZVI) to synthesize an alternative material for lead removal from aqueous solutions. Many experiments were conducted under several operating conditions in order to analyze the effectiveness of the produced material in Pb2+ abatement. The performance of MgO_nZVI was also compared with those detected using commercial microscopic Fe0 (mZVI) as a reactive material. The experimental findings showed a much greater reactivity of the supported nanoscopic iron particles. By means of a kinetic analysis of batch tests results, it was verified that, both for MgO_nZVI and mZVI, the lead abatement follows a pseudo-second-order kinetic law. The reaction rates were affected by the initial pH of the treatment solution and by the ratio between the Fe0 amount and initial lead concentration. The efficiency of MgO_nZVI in a continuous test was steadily around 97.5% for about 1000 exchanged pore volumes (PV) of reactive material, while by using mZVI, the lead removal was approximately 88% for about 600 PV. X-ray diffraction (XRD) and energy-dispersive spectroscopy EDS analyses suggested the formation of typical iron corrosion products and the presence of metallic lead Pb0 and Pb2+ compounds on exhausted materials.

The disposal of CRT monitors increases each year, generating millions of tons of waste containing various types of materials. The glass present in CRT tubes displayed about 20%-25% of lead oxide. If improperly disposed of, this glass can be leached directly in nature or may cause environmental contamination, especially with lead. Because of this leaching possibility, this waste is classified as Class I solid waste, according to the NBR 10004. Thermal processing of these glass tubes was seen as an alternative to remove lead from the glass matrix. Parameters such as reaction time, percentage of reducing agent, the reaction temperature, and atmospheric environment of the system were analyzed in this work. It was concluded that it is possible to remove the lead from the glass matrix by thermal processing. The removal of 92% of the lead from the glass was obtained at 800°C, a vacuum of 1.3 kPa, with 5% carbon as a reducing agent, and 18 hours of thermal processing.

Increasing device implantations, patient comorbidities, and longer life expectancy contribute to an increased need for lead extraction. Even if transvenous lead extraction (TLE) is a highly successful procedure, some serious procedural complications are reported. In order to identify those patients who are at higher risk, risk stratification scores were proposed. Areas covered: The major obstacles to lead extractions are represented by the body's response to the foreign implanted material and by the following development of fibrotic reaction between the lead and the vascular system. Several clinical factors and device features are associated with major complications and worse outcomes. Although different multiparametric scores predicting the safety and the efficacy of TLE procedures were reported, none of these scores were prospective evaluated. Expert commentary: A correct risk stratification is needed in order to refer complex patients to centers with proven experience and avoid futile procedures. Furthermore, the identification of high-risk patients allows to perform the extraction procedure in the operating room instead of electrophysiology lab. Albeit some risk scores able to predict adverse event in cardiac lead extraction were described, there are still several limitations to their use and reproducibility.

Electrospun nanofibers have been successfully applied to remove toxic and carcinogenic contaminants such as heavy metals from polluted water. In this study, an efficient adsorbent based on poly(ethylene terephthalate) (PET) nanofibers was developed following a cheap, versatile and scalable process. PET nanofibers were first produced by electrospinning, and their surface was chemically functionalized using a simple aminolysis process. The capacity of the resulting material to adsorb Pb(II) from synthetic solutions was evaluated as a function of the contact time, pH, and initial metal ion concentration. The adsorbent system presented a quick kinetic adsorption, reaching an extremely high maximum adsorption capacity of about 50 millimol (mmol) of Pb(II) per gram of adsorbent system after just 30 min. Moreover, the effect of competing metal ions, such as Ni(II), Cd(II) and Cu(II), was studied at different molar ratios. Finally, when tested in continuous flow mode, aminated PET (APET) nanofibers were able to remove 97% of Pb(II) ions in solution, demonstrating their potential for the remediation of heavy metal-contaminated water.

Introduction and objectives The rate of implanted cardiac electronic devices is increasing as is the need to manage long-term complications. Lead removal is becoming an effective approach to treat such complications. We present our experience in lead removal using different approaches, analyzing the predictors of the use of mechanical extractors/surgical removal. Methods Retrospective analysis of lead extractions in a series of 76 consecutive patients (mean age 70.4 ± 13.8 years, 73.7% men) between January 2009 and November 2015. Results One hundred thirty-five leads from permanent pacemakers (single chamber 19.7%; dual-chamber 61.8%), implantable cardioverter defibrillators (5.3%), and cardiac resynchronization devices (CRT-P 2.6%; CRT-D 7.9%) were removed, 72.5 ± 73.2 months after implantation. A total of 45.9% were ventricular leads, 40.0% atrial leads, 8.9% defibrillator leads, and 5.2% leads in the coronary sinus; 64.4% had passive fixation. The most common indications for removal were pocket infection (77.8%), infective endocarditis (9.6%), and lead dislodgement (3.7%). A total of 76.3% of the leads were explanted, 20.0% were extracted, and 3.7% were surgically removed. Extraction of the entire lead was achieved in 96.3% of the procedures. After logistic regression (age adjusted), time since implantation was the sole predictor of the need of mechanical extractors/surgical removal. All patients were discharged without major complications. There were no deaths at 30 days. Conclusion Our experience in lead removal was effective and safe. Performing these procedures by experienced electrophysiologists with an adequate cardiothoracic surgery team on standby to cope with any complications is required. Referral of high-risk patients to a high-volume center is recommended to optimize clinical success and minimize procedural complications.