Removal of Pb(II) ions using Chitosan oligosaccharide/carboxymethyl cellulose/kaolin clay blend

Heavy metal removal from wastewater has become a major environmental concern around the world. The performance of a chitosan-oligosaccharide-based hybrid (chitosan oligosaccharide (COS)/Carboxymethyl cellulose (CMC)/Kaolin clay (KC) ternary blend material prepared in the presence of Glutaraldehyde (Glu) ternary blend material for the adsorptive removal of lead (Pb) from waterwaste was investigated in this study. The structure of COS with amine and hydroxyl groups helps to remove Pb ions. FTIR and X-Ray diffraction were used to characterize of COS/CMC/KC + Glu blend. The removal of ions was assessed using batch adsorption studies, which varied parameters such as the influence of beginning concentration, adsorbent dose, and contact time. The elimination of Pb ions by adsorption was pH-dependent, with a maximum at pH 5. The favorability of the reported experimental values was validated using several theoretical models such as Freundlich and Langmuir isotherms, pseudo-first-order and pseudo-second-order kinetics. The Langmuir isotherm and pseudosecond-order best fitted for the adsorption.

Effects of Gum Arabic-Coated Magnetite Nanoparticles on the Removal of Pb Ions from Aqueous Solutions

To study the removal of lead (Pb) ions from aqueous solutions, novel magnetite nanoparticles (NPs) of Ni0.31Mg0.15Ag0.04Fe2.5O4 were synthesized by coprecipitation synthesis using metal sulfates, and then coated with Gum Arabic (GA). The prepared NPs were analyzed using various spectroscopic and analytical methods, such as X-Ray diffraction analysis (XRD), Field Emission Scanning Electron Microscopy (FE-SEM), Energy Dispersive X-ray spectroscopy (EDX), Fourier Transform Infra-Red spectroscopy (FT-IR), and Atomic Absorption Spectrophotometer (AAS). By using XRD analysis, the cubic inverse spinel structure of the prepared NPs was proven, showing average values of crystallite size, lattice constant, and density of 28.57nm, 8.32582Å, and 5.2890 g/cm3, respectively. FE-SEM analysis revealed the sphere-like shape of the nanoparticles with a measured crystallite size of 25.93nm. The existence of constituent elements was evidenced by EDX. FT-IR test proved the success of the coating process of magnetite NPs by the presence of the main characteristic absorption bands of GA in the FT-IR spectrum of GA-magnetite NPs. The adsorption of Pb ions by GA- magnetite NPs was shown by AAS analysis, where the concentration of Pb ions decreased from 25ppm to 6.6ppm, reaching 1.1ppm at the time of 25min. The porosity of the NPs and the carboxyl groups in GA played an important role in the process.

Adsorption of Pb Ions from Oily Wastewater by Anthraquinone Modified Carbon Nanotube

The aim of this research was to investigate the adsorption properties of anthraquinone modified carbon nanotube (ACNT) in oily wastewaters containing Pb ions. The modified adsorbents were characterized using Fourier transform infra-red spectroscopy and SEM analysis. The adsorption and regeneration studies were conducted in batch mode using a Taguchi (L16) orthogonal array to optimize experimental runs. The controllable factors used in this study consisted of: pH of the solution (A); adsorbent dosage (B); adsorbent type (C); contact time (D); temperature (F). The effects of each factor were studied at four levels on the removal efficiency of metals from aqueous solution. Concentrations of metal ions were assessed by atomic absorption spectrometer. The total optimum adsorptive removal of lead ions was obtained with C0 = 10 mg•l-1, T = 338 K, pH = 6, m = 0.020 mg and t = 60 min. The Langmuir model was representative to simulate adsorption isotherms. The adsorption kinetics of Pb adsorption by ACNT was modeled using the pseudo-first order, the pseudo-second order, and intraparticle diffusion kinetics equations. The results indicate that the pseudo-second order kinetic equation and intraparticle diffusion model were adequate to describe the adsorption kinetics.

Estimation of the phytoremediation potential of Alisma plantago-aquatica L. taken from different stations during water contamination by Cu and Pb (Russia, Vologda region)

Accumulation of Cu and Pb by Alisma plantago-aquatica L. plants under laboratory conditions on separate solutions (3 MPC) and changes in the content of heavy metals (HM) when placed on distilled water (control) were studied. The phytoremediation potential of Alisma plantago-aquatica, taken from different stations, is assessed: from conditionally clean habitat located in the middle course of Yagorba river (Cherepovets region) and from conditionally polluted habitat located on the bank of Serovka river within Cherepovets city. It is established that irrespective of what stations are taken plants of Alisma plantago-aquatica, they actively accumulate heavy metals, but plants from conditionally clean habitat accumulate more. More effective in the purification of water from heavy metals is Alisma plantago-aquatica from conditionally clean habitat. Alisma plantago-aquatica specimens from different areas are capable of excretion of Cu and Pb ions, the leaves being the most important in this. Alisma has a good phytoremediation potential and is suitable for inclusion in the composition of bioplato to clean the water of small rivers from Cu and Pb.

Enhancement of exchangeable Cd and Pb immobilization in contaminated soil using Mg/Al LDH-zeolite as an effective adsorbent

In the present study, experiments using zeolite and Mg/Al LDH-zeolite for immobilization of Cd and Pb ions in artificial soil were conducted.

Insights on Substitution Preference of Pb Ions in Sulfoaluminate Cement Clinker Phases

The doping behaviors of Pb in sulfoaluminate cement (SAC) clinker phases were systematically studied combined with density functional theoretical simulations and experiments. The results present that, in the three composed minerals of C4A3S, C2S, and C4AF, Pb ions prefer to incorporate into C4A3S by substituting Ca ions. Further analyses from partial density of states, electron density difference, and local distortions show that such doping preference can be attributed to the small distortions as Pb introduced at Ca sites of C4A3S. The results and clear understandings on the doping behaviors of Pb ions may provide valuable information in guiding the synthesis of Pb-bearing SAC clinker, thus should draw broad interests in fields from sustainable production of cement and environmental protection.