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A magnetic silver-containing coordination polymer was synthesized and its application as an adsorbent for removing lead ions more than 99% at optimum conditions from wastewater and seawater samples was developed. To characterize the silver–2–aminoterephthalic acid-functionalized Fe3O4 magnetic nanoparticles, various analyses including x-ray diffraction, field emission scanning electron microscopy, transmission electron microscopy, fourier-transform infrared spectroscopy, energy dispersive x-ray spectroscopy, vibrating-sample magnetometer, dynamic light scattering and zeta potential analysis were performed. Batch adsorption experiments were carried out using a flame atomic absorption spectrometry system for determining the lead concentration. Effective parameters on removal efficiency, such as extraction time, sorbent amount and pH of sample solution were optimized by "one at a time" method. The adsorption conformed to a Langmuir adsorption isotherm with a maximum adsorption capacity of 31 mg g−1 during 15 min. The kinetic of adsorption was consistent with Pseudo-second-order model. The results showed that the sorbent has an appropriate ability to remove Pb2+ ions through a spontaneous and endothermic procedure. [ABSTRACT FROM AUTHOR]

A new coating-based approach for water treatment was demonstrated using silicone nanofilaments (SNF) coatings. In view of some existing point-of-use (POU)/point-of-entry (POE) water treatment systems, where membranes or filters are used to build devices that allow individuals to treat water on their own at the point of consumption. The reported coating-based approach offers an advantage as contaminated water was treated upon contact with the functionalized SNF-coated surfaces, without additional pressure or energy requirement. Besides, the coatings took the shapes of the substrates and demonstrated some different formats can be potentially deployed for POU devices. To illustrate the suggested approach, glass substrates of three different shapes (flat microscopic slides, walls of vials, and three-dimensional (3D) filter frits) were employed. Substrates were readily coated with SNF under ambient conditions via gas phase deposition based on the previous developed protocol, subsequently modified with (3-Mercaptopropyl)triethoxysilane (MPTES), and were used to treat 200 ppb of trace lead ions in water. Results suggested that the coatings as a facile mean to render surfaces/containers functional towards trace lead removal, and enhanced performance compared to their non-coated counterparts. In addition, the oil sorption capacities of the coated frits were also evaluated. By rendering the as-prepared frits amphiphilic, they were used to treat trace lead, water-soluble methylene blue, and oil-soluble Oil Red O dyes. Overall, the study demonstrated and evaluated the use of the SNF coatings by treating some model contaminants in different formats than the existing approaches. The ease of preparation and the flexibility of the approach presented provide opportunities for the design of new water treatment systems and more accessible POU/POE devices. • The coated composites were prepared and functionalized under ambient conditions. • New water treatment models and potential POU devices were demonstrated. • Trace level of lead removal, 200 μg/L, was investigated for actual daily encounters. • 98 % lead removal was obtained in a wall-coated system by simply bringing into contact. • The coatings rendered composites amphiphilic for trace lead, dyes and oils removal. [ABSTRACT FROM AUTHOR]

For human health and environment safety, it is of great significance to develop novel materials with high effectiveness for removal of lead from not only aqueous solutions but also human body and traditional Chinese medicines. Here, functional kiwi peel composite, manganese dioxide decorated kiwi peel powder (MKPP), is proposed for the removal of Pb2+ effectively. The adsorption of Pb2+ in aqueous solution is a highly selective and endothermic process and kinetically follows a pseudo-second-order model, which can reach equilibrium with the capacity of 192.7 mg/g within 10 min. Comprehensive factors of hydration energy, charge-to-radius ratio and softness of Pb2+ make a stronger affinity between MKPP and Pb2+. The possible adsorption mechanism involves covalent bond, electrostatic force and chelation, etc. MKPP can be efficiently regenerated and reused with high adsorption efficiency after five cycles. Besides, MKPP can remove over 97% of Pb2+ from real water samples. MKPP can also alleviate lead poisoning to a certain extent and make the Pb level of TCM extract meet the safety standard. This work highlights that MKPP is a promising adsorbent for the removal of Pb2+ and provides an efficient strategy for reusing kiwi peel as well as dealing with the problem of Pb pollution. • Novel manganese dioxide decorated kiwi peel powder was fabricated. • Interactions for adsorption involved covalent bond, electrostatic force and chelation. • Functional adsorbent showed a satisfactory lead adsorption performance. [ABSTRACT FROM AUTHOR]

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.

Battery recycling generates large amount of effluent which contains the toxic Pb(II) beyond the permissible limit. This effluent was treated for the removal of Pb(II) by fixed bed adsorption onto steam-activated granular carbon. Effect of flow rate, bed diameter and bed height on the performance of fixed bed column was investigated. The experimental data was presented in the form of breakthrough curve. Bed exhaustion time, breakthrough time and adsorbent capacity were determined. The obtained experimental data were evaluated with the four kinetic models: Thomas, Yoon–Nelson, Adams–Bohart and Clark model. The data were fitted well to the Thomas, Yoon–Nelson and Clark model with correlation coefficient R2 > 0.96.

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.

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, the performance of carbon cloth (CC) modified with iodine (I2) doped polythiophene nanoparticles (PTh-NP) as an anode was investigated in a double chamber microbial fuel cell (MFC) for the purpose of simultaneous power generation and lead (Pb2+) removal using Shewanella putrefaciens as the biocatalyst. The CC with I2 doped PTh-NP displayed good electrochemical characteristics compared to pristine CC and the CC with undoped PTh-NP. A further increase in the electrical conductivity using the modified CC with biofilm was observed, which matured after 51 h, as evident from cyclic voltametry. The removal of lead for concentrations, viz., 20 ppm, 30 ppm, and 40 ppm, was analyzed. The optimum concentration was found to be 30 ppm with a maximum power density of 0.84 W/m2 and a current density of 1.45 A/m2 at an optimum resistance of 250 ohms. At the end of the process, total organic carbon (TOC) and Pb2+ removal of 95.1% and 89.6%, respectively, were obtained at the optimum concentration. Hence, this study demonstrates the possibility of utilizing MFC for treating low concentrated metal wastewater. [ABSTRACT FROM AUTHOR]

Eliminating soluble lead ion from wastewater through adsorption has been more critical with the nonstop anthropogenic activity releasing it as waste. This study focuses on synthesizing zinc oxide-modified graphene oxide (ZnO/GO) following the solvothermal method and evaluating its capacity in adsorbing Pb(II) ion. The synthesized ZnO/GO was characterized using X-ray Diffraction (XRD), Fourier-transform Infrared Spectroscopy (FTIR) and Scanning Electron Microscopy with Energy Dispersive X-ray (SEM-EDX) analysis; the results revealed that the graphene oxide (GO) had successfully bonded with zinc oxide (ZnO). The adsorption of Pb(II) on the functionalized ZnO/GO was studied under different experimental conditions, which confirmed the high adsorption capacity of ZnO/GO in removing Pb(II). The optimum pH and adsorbent dosage of ZnO/GO were at pH 5 and 0.16 g/L and the maximum adsorption capacity reached 909.09 mg/g. The most rapid adsorption occurred in the first 30 minutes of contact time with the equilibrium time achieved in 160 minutes and the adsorption isotherm and kinetic followed the Langmuir and pseudo-first order model. Therefore, the newly synthesized ZnO/GO showed superior adsorption capacity for Pb(II) compared to its pure GO. [ABSTRACT FROM AUTHOR]

Granular porous sorbents were normally used for heavy metals removal from water. To search for the new commercial sorbent and treatment strategy, an organic acrylic amine fiber (AAF) and phosphorus loading inorganic-organic AAF (P-AAF) were prepared and used for lead (Pb) removal from water. A new strategy of inorganic-organic coupling technology was proposed for Pb removal, based on the hypothesis of surface-induced precipitation mechanism. The AAF showed a Pb adsorption capacity of 417 mg/g from the Langmuir fitting, while the column filtration technology was further applied to measure the adsorption edge and applications. Effects of different initial Pb concentrations, hydraulic retention time, and co-existing P were considered in the filtration experiments. The presence of 0.8 mg/L P in water significantly improved the Pb breakthrough point from 15,000 to 41,000 bed volumes of water spiked with 85 µg/L Pb, while the P-AAF fixed bed showed better removal of Pb than AAF SEM/EDX and XRD spectra were employed for determining the surface functional groups and the formation of surface-induced precipitation of pyromorphite (Pb 5 (PO 4) 3 OH) on AAF. This study verified the application of AAF sorbent for Pb removal and the enhanced effect of coating P on AAF, thus improved our fundamental understanding and application of the surface chemistry process of Pb with P. Image, graphical abstract [ABSTRACT FROM AUTHOR]

The response surface methodology was used to investigate the removal of Pb (II) from an aqueous solution using banana peel with varying operating parameters in a batch mode. The central composite design was used to study the interactive effects of the operating parameters (initial concentration, pH of the solution, adsorbent dosage and the particle size). The banana peel was characterized by FTIR which showed the functional groups, while SEM and EDS were used to study morphology and elemental composition. The optimum removal of Pb(II) was 98.146 % at initial concentration 100 mg/L, pH 5, adsorbent dosage 0.55 g and particle size 75 µm. The deviation between the experimental and the model predicted percentage removal was 5.17 %. The analysis of variance showed that the regression model was significant with a low probability and the correlation coefficient R² value of 0.9153. The results showed that the biosorption of Pb(II) was highly influenced by the pH and the adsorbent dosage, while the particle size had little effect on the biosorption process. [ABSTRACT FROM AUTHOR]

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. [ABSTRACT FROM AUTHOR]

The present study aimed to develop the activated carbon from fruit waste like sapota peel and to optimize the condition of developed activated carbon for complete removal of lead ions from the desired concentration of a lead solution. The activated carbon was prepared from sapota peel by using sulphuric acid. The physicochemical characterization of the obtained activated carbon was done for various parameters along with analysis of crystal nature (XRD) and structural morphology (SEM). The optimum conditions for adsorption were studied by altering pH (2-10), agitation speed (50-250 revolution per minute), temperature (10-60°C), adsorbent dose (0.02-0.14 g) and contact time (30-240 minutes). The optimized conditions necessary for complete removal of lead ions by the prepared adsorbent were pH - 5.5, agitation speed - 200 revolutions per minute, temperature - 60°C, time - 3 hours and adsorbent dose - 0.12 g. This study can be further helpful in designing the process of wastewater treatment for the removal of toxic metals from water particularly lead by adsorption. [ABSTRACT FROM AUTHOR]

The present study provides two naturally available sources for making adsorbents, waste tyres and Bauhinia purpurea leaves, for the removal of lead from effluents. Equilibrium isotherms, kinetic models and thermodynamic studies were applied to observe the suitability of these adsorbents. Response surface methodology was adopted to investigate the influence of different process variables in lead adsorption process using both the adsorbents. For all the process parameters, the square and linear model terms were having significant effect than interactive model terms of lead adsorption process for both the adsorbents. The interaction effects of the process variables of X1X2, X1X3, X2X3 and X2X4 were highly influenced by the percentage removal of lead by using activated carbons prepared from waste tyres. To study the interaction effects of the process variables of X1X2, X2X3 and X2X4 were highly influenced by the adsorption efficiency of lead by using activated carbons prepared from Bauhinia purpurea leaves. All the squared terms, X1, X2, X3 and X4 show a negative influence on the adsorption of lead on the two adsorbents. The interaction effect between process variables of X1X2 (p: 0.000, t: 9.243), X1X3 (p: 0.03, t: 2.36), X2X3 (p: 0.000, t: 4.75) and X2X4 (p: 0.02, t: 2.71), were found to be statistically significant and have positive effect on adsorption efficiency using ACWT as an adsorbent. The interaction effect between process variables of X1X2 (p: 0.000, t: 8.1049), X2X3 (t: 5.9657, p: 0.000) and X2X4 (t: 5.9657, p: 0.000) was found to be statistically significant and positive effect on adsorption efficiency of lead, whereas other interactions were insignificant and did not influence the adsorption efficiency of lead using activated carbons of Bauhinia purpurea leaves adsorbent. Based on the statistical approach, the experimental results were analysed by using ACWT and ACBPL adsorbents for the removal of lead and the optimum process conditions were as follows: pH: 4.98 and 4.77, Ci : 140.01 mg/L and 105.7 mg/L, w: 0.12 g and 0.123 g, T: 314.46 K and 305.31 K and maximum adsorption efficiency of 95.64% and 95.55%, respectively. [ABSTRACT FROM AUTHOR]

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. [ABSTRACT FROM AUTHOR]

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.

Studies on liquid-liquid extraction and bulk liquid membrane (BLM) technique-based metal ion separation by a previously published Pb2+-selective acridono-18-crown-6 ether selector molecule were performed. The effects of the stirring speed, the quality of apolar organic membrane, the counterions of Pb2+, the pH of the aqueous phase, the concentration of the source phase, the concentration of the carrier in the BLM and the temperature on the Pb2+-separation were investigated. Moreover, the effects of the competitive inhibition due to the presence of Ag+, Ca2+, Co2+, Cu2+, K+, Mg2+, Na+ and Zn2+ as competing ions in a multicomponent aqueous source phase of different ion-concentrations were also studied. After a proper dilution of the multicomponent aqueous source phase, excellent Pb2+-selectivity was achieved without a significant reduction in the efficiency compared to the liquid membrane transport of single-component systems. Based on the BLM-cell studies the applied selector molecule proved to be suitable for the development of liquid membrane-based Pb2+-selective separation methods, which can be greatly aided by the analysis of the effects on the separation and by the optimization of the parameters of the process discussed here. [ABSTRACT FROM AUTHOR]

This study aimed to investigate the Pb2+ removal performance of cotton-based biochar (CB) and magnetic modified cotton-based biochar (MCB). The scanning electron microscopy revealed that MCB exhibiting a porous honeycomb structure with a specific surface area of 613.69 m²/g which bigger than that of CB (356.68 m²/g). The Fourier transform infrared spectrum analysis indicated the presence of metal oxides and hydroxides in MCB and the functional groups of O-H, C=O, and C=C in both MCB and CB. The signal of Fe3O4 and Fe3C was observed in X-ray diffraction analysis of MCB, which indicated the success of magnetic modification of MCB. The maximum monolayer adsorption capacities (Qm) of MCB and CB on Pb2+ were 208.33 and 156.25 mg/g, respectively. The adsorption kinetics of MCB and CB were both best fitted with the pseudo-second-order model (R² > 0.99), and the adsorption isotherms of the two biochar were well-described by the Langmuir adsorption model (R² > 0.99). The results of this study revealed the significant physicochemical difference of two biochar and indicated that magnetic modification can enhance the Pb2+ adsorption capacity of biochar, suggesting that MCB is a potential adsorbent for wastewater treatment. [ABSTRACT FROM AUTHOR]

In this study, lignin was extracted using ultrasonic and then, by the gelation-solidification method, the extracted lignin was used as reinforcement for the synthesis of a novel biocomposite as biosorbent for removal of lead heavy metal from aqueous solutions. The structural and chemical characteristics of biocomposite were determined by FESEM, EDX, FTIR, and BET analyses, respectively. Biocomposite beads were used as an efficient adsorbent in the lead removal process from aqueous solutions in different conditions. Also, point zero charge studies and the effective parameters on adsorption such as contact time, pH, temperature and initial concentration, kinetics, isotherms, and thermodynamics of the adsorption, and adsorbent regeneration and reuse were investigated. The maximum adsorption capacity of the adsorbent was obtained 344.83 mg/g at C 0 = 210 mg/L, T = 328 K, and pH = 5. The experimental kinetic and equilibrium data were well adjusted with pseudo-second-order kinetic models and Langmuir and Temkin isotherm models, respectively, according to linear regression (R2), chi-square statistic (χ2), and the sum of the squares of the errors (SSE). The thermodynamics parameters were analyzed and the results showed an endothermic and spontaneous adsorption process. Regeneration and reuse results of the synthesized biocomposite represented highly adsorption efficiency after five adsorption cycle stages. [ABSTRACT FROM AUTHOR]

In this study, a chemical fractionation process using sulfuric acid was investigated to recover hemicellulose from barley straw under ultrasonic, and then, the extracted hemicellulose was mixed with sodium alginate to prepare the biosorbent with the gelation-solidification method. The prepared biosorbent was characterized by Field Emission Scanning Electron Microscope (FESEM), Energy-dispersive X-ray spectroscopy (EDX), Fourier transform infrared spectroscopy (FTIR), high-performance liquid chromatography (HPLC), and Brunauer-Emmett-Teller (BET) surface area analysis and used for efficient toxic lead removal from aqueous solutions. Different factors influencing adsorption, mechanisms, kinetics, isotherms, and thermodynamics were explored. The rate-controlling step in the early stages of adsorption was film diffusion that was determined by Boyd, Webber, and Dubinin-Radushkevich models. The maximum Pb2+ adsorption capacity was obtained 277.78 mg/g in pH = 5, 0.4 g/L adsorbent dosage, 210 mg/L initial Pb2+ concentration, and 55 °C temperature and the removal efficiency was over 99%. Besides, after 5 reuse cycles, the high lead adsorptivity was observed. Due to the benefits of the prepared biosorbent such as high adsorption capacity, renewability, low-cost, and biodegradability, they can be effective adsorbents for the treatment of heavy metals wastewaters. Image 1 • Barley straw was hydrolyzed to extract hemicellulose under ultrasonic. • Cross-linked biocomposite of extracted hemicellulose was successfully prepared. • The biocomposite was used for enhanced lead removal from aqueous solution. [ABSTRACT FROM AUTHOR]

Ethylenediaminetetraacetic dianhydride modified coconut frond (ECFP) was prepared, characterized and applied as a potential adsorbent to remove Pb(II) ions from aqueous solutions. Factors influencing adsorption such as pH of the solution, adsorbent dosage, Pb(II) concentration, contact time, and temperature were investigated. The optimum conditions for adsorption of Pb(II) ions were at pH 4 and dosage of 0.02 g. Adsorption reached its equilibrium state in 30 min for all Pb(II) concentrations. Chemisorption was suggested as the rate-limiting step as the adsorption process correlated well with the pseudo-second-order kinetics model. Based on adsorption isotherm results, Langmuir model fitted the experimental data well, and the maximum adsorption capacity was 84.03 mg.g-1 at 300 K. Based on the thermodynamic study, Pb(II) adsorption occurred spontaneously with the enthalpy and entropy changes recorded were 0.0615 kJ mol-1 and 241.28 J K-1 mol-1, respectively. It was found that the nature of adsorption was endothermic as the ΔHo value obtained was positive. [ABSTRACT FROM AUTHOR]

In this study, synthesis of iron oxide doped methyltrimethoxysilane (Fe2O3-MTMOS) spherical magnetic nanocomposite was reported, based on the simple methodology for the enhanced removal of lead ions from wastewater. The synthesized magnetic nanocomposites were comprehensively characterized by using Fourier transform infrared spectrometer, field emission scanning electron microscope, X-ray diffraction, and energy dispersive X-ray spectroscopy. Fe2O3-MTMOS nanocomposite was then employed as an adsorbent for lead (Pb2+) and various adsorption parameters, such as pH, adsorbent dosage, contact time, and initial lead (Pb2+) ions concentration were analyzed and optimized. Adsorption process has been validated with different kinetic and isotherm model, where the experimental data was found to be in good agreement with pseudo-second-order (R² = 0.986) and Freundlich isotherm (R² = 0.993) as compared with other models. The adsorption capacity of the spherical Fe2O3-MTMOS nanocomposite was found to be relatively higher (105.5mg g–1) for lead ions. Adsorption isotherm, kinetic model, and free energy models predicted multilayer sorption pattern for lead ions onto spherical Fe2O3-MTMOS under physical adsorption forces. [ABSTRACT FROM AUTHOR]

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Background: Many patients awaiting heart transplantation (HTX) have a cardiac implantable electronic device (CIED). Lead removal is often still a part of the HTX procedure. Abandoned lead fragments carry a risk for infections and prohibit magnetic resonance imaging (MRI) imaging. This study evaluated the concept of an elective lead management algorithm after HTX. Methods and Results: Between 2009 and 2018, 102 consecutive patients with previously implanted CIED underwent HTX. Lead removal by manual traction during HTX was performed in 74 patients until December 2014. Afterward, treatment strategy was changed and 28 patients received elective lead extraction procedures in a hybrid operating room (OR) using specialized extraction tools. Total of 74 patients with 157 leads underwent lead extraction by manual traction during HTX. The mean lead age was 32.3 ± 38.7 months. Postoperative X‐ray revealed abandoned intravascular lead fragments in 31(41.9%) patients, resulting in a complete lead extraction rate of only 58.1%. The high rate of unsuccessful lead extractions led to the change in the extraction strategy in 2015. Since then, HTX was performed in 28 CIED patients. In those patients, 64 leads with a mean lead age of 53.8 ± 42.8 months were treated in an elective lead extraction procedure. No major or minor complications occurred during lead extraction. All leads could be removed completely, resulting in a procedural success rate of 100%. Conclusion: Our results demonstrate that chronically implanted leads should be removed in an elective procedure, using appropriate extraction tools. This enables complete lead extraction, which reduces the infection risk in this patient population with the necessity for permanent immunosuppressive therapy and allows further MRI surveillance. [ABSTRACT FROM AUTHOR]

Natural polymer Moringa oleifera seed as coagulant and bentonite clay as adsorbent were used for preparing novel composite coagulant. Results obtained from FTIR, SEM, TEM and P-XRD show that the bentonite clay and M. oleifera seed biopolymers physico-chemically interact with each other during the preparation of clay-polymer composite. The FTIR results show that the major functional groups present in bentonite clay and M. oleifera seed are integrated at nano levels in the novel composite to remove heavy metals from aqueous systems. The coagulo-adsorption using clay-polymer composite may be used for the adsorption of heavy metals ions from the aqueous systems. It becomes possible due to the structural characteristics of the clay crystallites together with the functional attraction of the biopolymer and it results in the formation of clay-polymer metal complexes. The clay-polymer nano-composite of M. oleifera seed and bentonite clay showed considerable cadmium, chromium and lead removal property. [ABSTRACT FROM AUTHOR]

In this study, crayfish shell was pyrolyzed at 600 °C to obtain an unmodified biochar (CS600). MgCl2 was used as a modifier to pretreat crayfish shell to produce a modified biochar (CS600-MgCl2) under the same pyrolysis conditions. The two biochars were characterized for physicochemical properties and evaluated for lead (Pb2+) sorption ability to determine the modification mechanism. Mono-element batch adsorption experiments were conducted to compare the sorption performances of CS600 and CS600-MgCl2 to Pb2+ in aqueous solutions. All the experiments were carried out at pH of 7. According to the Freundlich–Langmuir model, CS600-MgCl2 had a higher adsorption capacity (152.3 mg/g) than CS600 (134.3 mg/g). FTIR, SEM, XRD, BET, and ICP analyses were applied to inform the interpretation of the mechanism. CS600 was calcium-rich and mainly removed Pb2+ through the ion exchange mechanism by replacing Ca2+ in the biochar. The increased Pb2+ adsorption capacity of CS600-MgCl2 was mainly due to the enlarged specific surface area and the formation of Mg3(OH)5Cl·4H2O on the modified biochar. Findings of this study suggest that both CS600 and CS600-MgCl2 can be used to remove heavy metal ions from wastewater and MgCl2 can improve the sorption performance of biochar. [ABSTRACT FROM AUTHOR]

The Box–Behnken design response surface methodology (BBD-RSM) was utilized to model and optimize electrodialysis process for lead (Pb(II)) removal from seaweed extracts. The experiments were conducted with three influential variables including the operational voltage and initial lead concentration and flow rate using a full 24 factorial experimental design. According to the ridge and canonical analysis, the effect of major factors on Pb(II) removal in ED process follows the order: operational voltage > flow rate > initial lead concentration. Under the optimized parameters, the lead removal of 76.52% was acquired which showed good agreement with model predicted (75.45%) result. The feasibility of RSM model for lead removal response was verified by analysis of variance (ANOVA), which indicated a good reproducibility and fit of the experimental data with a high value coefficient (R² = 0.9945 and Radj² = 0.9874). The results suggested that electrodialysis with Box–Behnken design response surface methodology is regarded as the promising technology for lead removal from seaweed extracts. [ABSTRACT FROM AUTHOR]

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.

Abstract 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.

The development of hydroxyapatite nanorods (nHAp) and hydroxyapatite/chitosan nanocomposite (nHApCs) was sought as potential sorbents for the removal of lead ions from aqueous lead-containing solutions in a batch adsorption experiment. The high resolution transmission electron microscopy, energy dispersive X-ray analysis, X-ray diffraction, Fourier transform infrared spectrophotometry and Zeta potential measurements were all combined to reveal the morphology, composition, crystal structure, functionality and stability of the prepared sorbents. The equilibrium concentration of Pb2+ ions was identified by the atomic absorption spectrophotometry. The kinetics of the sorption process was investigated together with the influence of initial lead ions concentration, sorbent dosage and solution pH on the sorption capacity. The sorption process followed pseudo-second-order kinetics, where 20 min was quite enough to attain equilibrium. Two models of adsorption isotherms (Freundlich and Langmuir) were employed to correlate the data in order to understand the adsorption mechanism. Interestingly, in one of the experiments, for a 200 mL solution (pH = 5.6) containing 100 ppm lead ions, a sorbent dosage of 0.4 g nHAp could achieve a complete removal for lead ions. However, typically, the sorption capacities of nHAp and nHApCs to lead ions were 180 and 190 mg/g respectively, which appear excellent for lead removal.

Calcium-containing biochar （ES-BC） was prepared by pyrolyzing eggshell and kitchen wastes， and the ES-BC composite was used to remove phosphate （marked as ES-BC/P）. Based on the high affinity of phosphate and carbonate to lead， the ES-BC/P was then used to remove lead from the water. The results showed that， in the appropriate dosage， ES-BC/P could remove lead efficiently at different initial concentrations （1-100 mg·L -1 ）， and the removal efficiency could reach to 99%. Meanwhile， the release of phosphorus could be ignored after the reaction. As ES-BC/P was alkaline， and the lead-containing solution was weakly acidic， the addition of ES-BC/P could adjust the pH of the system automatically. The reaction kinetics and isotherm experiments showed that the lead removal by ES-BC/P was mainly monolayer chemisorption with a maximum adsorption capacity of 493.12 mg·g -1 （318 K）. The characterization results showed that lead was mainly removed through the ion exchanges of Pb 2+ in the solution with Ca 2+ in ES-BC/P. Then， the Pb 2+ combined with CO 3 2- and PO 4 2- to form many precipitates， including Pb 5 （PO 4 ） 3 OH， Pb 10 （PO 4 ） 6 （OH） 2 ， PbCO 3 ， and Pb 3 （CO 3 ） 2 （OH） 2 . In summary， the ES-BC/P material could achieve the efficient removal of lead from the water， thereby realizing the resource utilization of the wastes.

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). [ABSTRACT FROM AUTHOR]

Lead, is the most common toxic metal that causing damage to the environment and human health due to its accumulation and persistence in the environment. The possibility of using biosorption unmodified rice straw (RS) was studied to eliminate lead ions from synthetic industrial wastewater. The impact of the initial concentration for lead (5–200 mg/l) and the contact time (10–120 min) were studied at 25°C and pH 5 of stirring solutions. Different analytical techniques such as Scanning Electron Microscope (SEM), Energy dispersive X-ray (EDX), and Fourier-transform infrared spectroscopy (FTIR) were used to figure out the change of rice straw adsorption capacity Moreover, The kinetic models pseudo-first and secondorder and both of Freundlich and Langmuir isotherm models have been tested. The results obtained show a significant removal of the lead content by approximately 94 % using unmodified rice straw (RS). Adsorption data was fitted with Freundlich isotherm model and pseudo - second order kinetics for unmodified rice straw. [ABSTRACT FROM AUTHOR]

Fe3O4@SiO2@THPP (MSTHPP) nanocomposite was prepared as an adsorbent for the removal of lead ions. The structural characteristics of thisnanocomposite were determined using Fourier transform-infrared (FT-IR) spectroscopy, scanning electron microscopy (SEM), transmission electron microscopy, x-ray diffraction, vibrating sample magnetometry (VSM), and N2 adsorption-desorption analyses. SEM images showed that the magnetic nanoparticles have uniform morphologies with a mean size of 20 nm. The magnetic properties of the synthesized nanocomposite were measured on a VSM with maximum saturation magnetization values of 40 emug-1 and 10 emug-1 for Fe3O4@SiO2 and MSTHPP nanocomposites, respectively. MSTHPP has been efficiently used to remove lead ions from aqueous solutions. After the lead sorption process, the nanocomposite was magnetically separated from the mixture and showed good reusability. The effects of pH, contact time, adsorbent dosage and initial concentration of lead in the removal of lead were investigated. Optimization of the parameters was performed by using Taguchi design method to obtain the maximum removal efficiency. The optimized condition can be achieved when pH, contact time, adsorbent dosage and initial concentration of lead are 5.3 min, 30 min, 50 mg, 20 ppm, respectively. The M, MS, and MSTHPP lead removal efficiency was found to be 18%, 25%, and 97%, respectively. [ABSTRACT FROM AUTHOR]

This study compared the removal of lead from aqueous solutions by cantaloupe peels (CP) as biosorbent against cement kiln dust (CKD) as an industrial byproduct. CP and CKD were characterized by pH, total carbon, nitrogen, and hydrogen content, thermo-gravimetric analysis (TGA), scanning electron microscopy (SEM), energy dispersive spectroscopy (EDX), Fourier transform infrared (FTIR), surface areas and pore volume to clarify the differences of physicochemical properties. CKD expressed a high affinity for removal of Pb2+ in all examine conditions, while CP was significantly affected, which reflects dissimilarity in the retention mechanisms defendant in CKD and those pursued by CP. The results were confirmed by changes in the FTIR and SEM images before and after sorption experiments. The experimental isotherms data were examined by Freundlich, Langmuir and Temkin isotherm equations. Langmuir isotherm model was more fitted to both sorbents with the highest correlation coefficient. The kinetic data were evaluated by fractional power, Elovich, pseudo- first order, and pseudo-second-order kinetic models. The pseudo-second-order kinetic model was found to adequately explain the kinetics and correlate with the experimental data well. The thermodynamic parameters revealed that the removal of Pb+2 by both CP and CKD at 298K-323 ± 2 K was a spontaneous and exothermic process. The results exposed that CP and CKD could be used as an efficient sorbent for lead removal from aqueous solution with privileges for CKD in all examine conditions. [ABSTRACT FROM AUTHOR]

In this study, crayfish shell was pyrolyzed at 600 °C to obtain a calcium-rich biochar (CS600). The biochar was saturated with Pb2+ in batch adsorption experiment. Six desorption reagents including HCl, HNO 3 , H 2 SO 4 , NaOH, EDTA and EDTA-2NaCa were then used to desorb Pb2+ from the post-adsorption CS600 to determine the desorption mechanism. Lead adsorption experiments were performed to determine the adsorption capacity of the regenerated CS600. HCl, HNO 3 , EDTA and EDTA-2NaCa presented good desorption effect with desorption rates all over 80%. Most of the regenerated biochars lost their lead adsorption ability due to the destruction of CaCO 3 mineral on their surface. Only the one desorbed by EDTA-2NaCa retained a preferable lead adsorption capacity. EDTA-2NaCa thus is a promising desorption reagent of CS600 for the removal of lead from aqueous solutions. [ABSTRACT FROM AUTHOR]

The nanoparticles have been prepared and employed as excellent adsorbents for the sequestration of heavy metal ions and hazardous impurities from the aqueous media. The surface morphological, textural and structural properties of nanoparticles have been modified, which are capable and potentially useful for the remediation of metal ions. Several metals (oxides, doped, nanocomposites of Fe, Ti, Zn, SiO2, SiC, Mo, Co, Ni, Zr, Mn, Si, S, Al, Cu, Ce, graphene, CNTs) were reported an efficient adsorbents for the removal of lead (Pb) ions from aqueous media and polluted water. The present review focuses on different kinds of nanoparticles such as metal oxides, carbon based and host supported employed for removal of Pb ions under varying experimental conditions such as pH, temperature, contact time and concentrations. The preparation strategies, physicochemical properties and adsorption are also discussed. Based on studies, it was found that the smart materials are affective adsorbents for the purification of wastewater containing Pb ions and could possibly extended for the remediation of other heavy metal ions. [ABSTRACT FROM AUTHOR]

Hybrid microsphere of polyacrylic acid (PAA) grafted TiO 2 /SiO 2 /Fe 3 O 4 (TSF-PAA) was synthesized via coating polyacrylic acid on the core-shell-shell TiO 2 /SiO 2 /Fe 3 O 4 (TSF) structure with the aid of plasma technique. The synthesized microsphere was applied to remove Pb2+ from water. The state-of-the techniques including TEM, FTIP, TGA, and XPS were used to characterize the morphology and the surface functionalities of the microsphere and confirmed that PAA was successfully grafted on TSF surfaces and active functional groups were introduced. A combination of the BET, VSM, and XRD results showed that plasma treatment decreased surface area of TSF by 36%, whereas its magnetic property and crystalline structure were not significantly altered. Both the Pb2+-sorbed magnetic TSF and TSF-PAA can be separated with a magnet from the aqueous phase. The pH and dosage changes of the microspheres exerted an intense influence on their lead removal efficiency. Compared to TSF, the removal capacity of Pb2+ by TSF-PAA was considerably improved from 65% to 95%, attributable to the fact that PAA coating induced by plasma treatment additionally introduced carboxylic and hydroxyl groups to TSF. Their introduction greatly enhanced the interaction between Pb2+ and TSF-PAA relative to that with TSF, which had hydroxyl groups only as supported by XPS analysis. Unlabelled Image • A polyacrylic acid (PAA)-coated magnetic microsphere was synthesized. • PAA grafting introduced abundant hydrophilic moieties to TiO 2 /SiO 2 /Fe 3 O 4. • The synthesized microsphere is a promising material for lead removal from water. • Plasma technique is very useful for inert material surface property modification. [ABSTRACT FROM AUTHOR]

Biochar from camphor leaves was activated by low-cost cold KOH process (ABC) to improve Pb(II) removal from aqueous solution. Then ABC was characterized by Fourier transform infrared spectroscopy, X-ray diffraction, scanning electron microscopy and N2 adsorption-desorption to reveal the benefits of cold KOH activation. The high adsorption capacity of ABC mainly results from oxygen-containing groups, porous structure and large surface area. Effect of factors including dose of ABC, pH, ionic strength, adsorption time, and temperature on Pb(II) adsorption was investigated by monofactor experiments. Through comparison with biochar (BC), optimization of ABC adsorption was revealed by kinetics, isotherms and thermodynamics. Pb(II) adsorption onto ABC is well described by pseudo-second-order kinetics and Langmuir isotherm, implying that chemisorption and monolayer adsorption are the rate-limiting steps. The thermodynamics indicates that Pb(II) adsorption onto ABC is spontaneous and exothermic. After cold KOH activation, the maximum adsorption capacity of Pb(II) onto ABC is 90.09 mg g-1, higher than 62.27 mg g-1 of BC. ABC has an excellent dynamic and thermodynamic performance comparing with BC. [ABSTRACT FROM AUTHOR]

Drinking water is a potential source of human exposure to lead (Pb2+), which can induce several health effects upon exposure to low dose for a long period. In particular, the children and young populations are the vulnerable groups. Removal of Pb2+ from drinking water using an inexpensive adsorbent is a challenge. In this research, activated carbon adsorbent was developed using jute stick, an agricultural by-product. Following carboxylic acid functionalization, the jute stick activated carbon (JSAC) was applied for Pb2+ removal from aqueous solution. The carboxylated JSAC (JSAC-COO−) was characterized using several techniques. The surface area of the JSAC-COO− was 615.3 m2/g. The JSAC-COO− was tested for variable concentrations of Pb2+ (10 and 25 mg/L) at different pH (4.0 and 7.0), temperature (15 °C and 27 °C), and contact periods (1, 5, 10, 15, 30, and 60 min). Up to 99.8% removal of Pb2+ was achieved for these concentrations of Pb2+ within 15 min of contact time. The adsorption process followed standard kinetics, and the adsorption capacity was > 25.0 mg Pb2+/g of JSAC-COO−. The JSAC-COO− can be used for fast and easy removal of Pb2+ from aqueous solution, which has the potential for domestic and industrial applications. [ABSTRACT FROM AUTHOR]

Wholly heterocycles-based polyamide-sulfide (PAS) containing pyridine and thiazole rings with thioether linkage was synthesized and used as a novel adsorbent for lead ion removal from water. The polymer adsorbent was fully characterized via FTIR, NMR and scanning electron microscopy (SEM). The thermal properties of the synthesized polyamide were also studied by thermogravimetric analysis and the outcome showed that the polymer has a good to moderate thermal stability. The SEM was used to investigate the morphology of the wholly heterocycles-based polyamide and the outcomes displayed a porous and globular-like morphology, which guarantee effective metal adsorption. Pb(II) ion removal capacity of the synthesized polymer was studied by varying the contact time and the adsorbent concentration. The maximum removal of Pb(II) was obtained as 99%. Equilibrium behavior and kinetic of the adsorption were also investigated using prevalent isotherm and kinetic models. The adsorption capacity was obtained to be around 714 mg g−1. The Langmuir isotherm and the pseudo-second order kinetic model suggested superior agreement with the equilibrium and kinetic adsorption data, respectively. Generally, the results of this research demonstrated that the synthesized polymer is a super-adsorbent for heavy metal removal from water. [ABSTRACT FROM AUTHOR]

• Co-pyrolysis biochars have higher Pb removal capacities than original biochar. • Metaphosphate within co-pyrolysis biochar promoted Pb sorption. • Carbon stability of co-pyrolysis biochars is enhanced compared with original biochar. When used separately, biochar and orthophosphate are good materials to remove Pb from water, but few studies have been done on Pb removal by biochar-orthophosphate composite. Here biochar-orthophosphate composites were prepared by co-pyrolyzing rape straw with orthophosphate (Ca(H 2 PO 4) 2 ·H 2 O / KH 2 PO 4) at ratio of 5:1 (W:W), noted as WBC-Ca and WBC-K, respectively, so as to explore the Pb removal capacities and mechanisms of co-pyrolysis biochars. The sorption isotherms of Pb were well fitted with Langmuir model and the maximum sorption capacities of Pb by original biochar, WBC-Ca, and WBC-K were 184.1, 566.3 and 1559 mmol kg−1, respectively. The results of FTIR, XRD, and XPS analyses showed that phosphorus in biochar played an important role to remove Pb by forming lead-precipitates. However, the species of lead-precipitates in three types of Pb-loaded biochars were Pb 5 (PO 4) 3 Cl, Pb 2 P 2 O 7 , and Pb n/2 (PO 3) n , individually, and that was because speciation of phosphorus had undergone significant thermochemical transformation during pyrolysis process. Orthophosphate in WBC-Ca was mainly transformed to pyrophosphate, while orthophosphate in WBC-K was transformed to both metaphosphate and pyrophosphate. The present results warrant the promising application of co-pyrolysis biochar derived from rape straw and orthophosphate in removal of Pb from wastewater. [ABSTRACT FROM AUTHOR]

Sugar industrial effluents possess high amounts of toxic pollutants and contaminate the receiving sites. Treatment of contaminated sites by using microorganisms provides an alternate to conventional methods hence demands in the identification of metal tolerant microorganisms has been increasing day by day. Therefore in this study soil samples collected from Tanuku sugar factory residual effluent point (bank of Gosthani river), west Godavari district A.P were analyzed for the bacterial tolerance to Copper (Cu), Zinc (Zn) and Lead (Pb) in their chloride forms. Additionally, the study was carried out to identify the metal tolerant bacteria by morphological, biochemical and 16S rRNA gene sequencing studies. Four potential bacterial isolates were selected to analyze metal tolerance against CuCl2, ZnCl2, and PbCl2. The sequences were compared with those in NCBI and submitted in gene bank with accession numbers MK100333 (Paenibacillus cookie), MK100334 (Bacillus cereus), MK100335 (Aneurini bacillus sp) and MK100387 (Paenibacillus sp.). A Phylogenetic tree was constructed to Paenibacillus sp. the highly efficient bacterial strain among the four isolates using MEGA 7 soft ware. The results of this study showed that P. dentritiformis had multiple metal tolerances (Cu, Zn and Pb) up to 500mg/L after 72 hrs. The identified bacterial strain proved to be the strong heavy metal tolerant bacterial strain. Hence, its usage will be helpful in the treatment of heavy metals specifically Cu, Zn and Pb contaminated soils and further optimization of these cultures is required to improve its metal resistant capacity. [ABSTRACT FROM AUTHOR]