A Physiological behavior and tolerance of Lactuca sativa to lead nitrate and silver nitrate heavy metals

This study goal to evaluate the effects of different concentrations of lead (Pb) and silver (Ag) on germination, initial growth and anatomical alterations of Lactuca sativa L. Plants use various mechanisms to reduce the impacts caused by anthropic action, such as xenobiotic elements of soils and water contaminated by heavy metals. These metals were supplied as lead nitrate and silver nitrate and the following treatments were established: control for both metals, maximum dose of heavy metals, for arable soils, allowed by the National Council of the Environment (Ag = 25 mg. Kg-1, Pb = 180 mg. Kg-1), double (Ag = 50 mg. Kg-1, Pb = 360 mg. Kg-1) and triple (Ag = 75 mg. Kg-1, Pb = 540 mg. Kg -1) of this dosage. Vigor and germination tests of the seeds and possible anatomical changes in the leaves and roots of lettuce plants were performed. The species showed a high capacity to germinate under Pb and Ag stress, and the germination was never completely inhibited; however, the germination decreased with increasing Pb concentrations, but not under Ag stress. The use of increasing doses of metals reduced seed vigor and increased chlorophyll content. An increase in biomass was also observed in plants from treatments submitted to Pb. The phytotoxic effects of metals were more pronounced at 15 days after sowing. Anatomically, L. sativa was influenced by metal concentrations, and had a reduction of up to 79.9% in root epidermis thickness at the highest Pb concentration, although some structures did not suffer significant changes. The results suggest that L. sativa presents tolerance to high concentrations of heavy metals, showing possible mechanisms to overcome the stress caused by these metals. In this research lettuce possibly used the mechanism of exclusion of metals retaining Pb and Ag in the roots preserving the photosynthetic apparatus in the aerial part of the plants. In general, the chemical element Pb was more toxic than Ag, in these experimental conditions.

Ionization Radiation Shielding Effectiveness of Lead Acetate, Lead Nitrate, and Bismuth Nitrate-Doped Zinc Oxide Nanorods Thin Films: A Comparative Evaluation

The fabrication of Nano-based shielding materials is an advancing research area in material sciences and nanotechnology. Although bulky lead-based products remain the primary choice for radiation protection, environmental disadvantages and high toxicity limit their potentials, necessitating less costly, compatible, eco-friendly, and light-weight alternatives. The theme of the presented investigation is to compare the ionization radiation shielding potentialities of the lead acetate (LA), lead nitrate (LN), and bismuth nitrate (BN)-doped zinc oxide nanorods-based thin films (ZONRs-TFs) produced via the chemical bath deposition (CBD) technique. The impact of the selected materials’ doping content on morphological and structural properties of ZONRs-TF was investigated. The X-ray diffractometer (XRD) analyses of both undoped and doped TFs revealed the existence of hexagonal quartzite crystal structures. The composition analysis by energy dispersive (EDX) detected the corrected elemental compositions of the deposited films. Field emission scanning electronic microscope (FESEM) images of the TFs showed highly porous and irregular surface morphologies of the randomly aligned NRs with cracks and voids. The undoped and 2 wt.% BN-doped TFs showed the smallest and largest grain size of 10.44 nm and 38.98 nm, respectively. The linear attenuation coefficient (µ) values of all the optimally doped ZONRs-TFs measured against the X-ray photon irradiation disclosed their excrement shielding potency. The measured µ values of the ZONRs-TFs displayed the trend of 1 wt.% LA-doped TF > 1 wt.% LN-doped TF > 3 wt.% BN-doped TF > undoped TFs). The values of μ of the ZONRs-TFs can be customized by adjusting the doping contents, which in turn controls the thickness and morphology of the TFs. In short, the proposed new types of the LA-, LN- and BN-doped ZONRs-TFs may contribute towards the development of the prospective ionization radiation shielding materials.

Effects of Lead Nitrate Induced Histological Changes in Liver of Male Sprague Dawley Rats

Lead is a highly toxic agent and a potent risk factor for various diseases as its quantity in an environment is increasing day by day. Aim: To observe and analyze the lead nitrate induced histomorphological changes in the liver of Sprague Dawley rats. Study Design: Experimental Study. Methodology: Animals of group A (control) were fed on normal diet but the animals of group B were given 50mg/kg of lead nitrate dissolved in 10ml of distilled water through oral gavage for 14 days daily. SPSS version 22 was used for data analysis. All the quantitative data was expressed as means ± SD. One Way ANOVA followed by Post Hoc Tukey test was applied. Results: Degenerative effects were noted. The number of Inflammatory and Kupfffer cells is increased with decreased in the body weight. Steatosis and central vein congestion were also present. Conclusion: It was concluded that degenerative effects histologically may be due to oxidative stress produced by formation of free radicals and denaturation of proteins by lead nitrate. Keywords: Lead, Liver, Central Vein Congestion, Oxidative Stress and Free Radicals.

Influence of different anionic charges in lead compounds in the remediation of lead by Eleusine indica (Gaertn)

The study was carried out to investigate the remediative capacity of Eleusine indica in lead-polluted soil. Soil samples were collected near student hostel (hall 5) in the University of Benin. The soil samples were sun dried to constant weight and was pulverized with wooden roller and sieved with a hand sieve of 2 mm mesh size. The sieved soil was spiked with 0.625 g lead nitrate (PbNO3), lead sulphate (PbSO4), lead carbonate (PbCO3), lead acetetrahydrate (PbC2H6) and lead chloride (PbCl2) separately in three replicate using aqueous standard solutions. Tillers of Eleusine Indica were placed in the metal polluted soil immediately and the experiment was allowed to stay for 15 weeks. The result showed that the uptake efficiency for Eleusine indica in both shoots and roots for lead nitrate was 0.016% and 0.8%, lead sulphate 0.016 % and 0.352 %, lead carbonate 0.064% and 0.496 %, lead acetetrahydrate 0.032 % and 0.688 %, and lead chloride 0.08 % and 0.72 % respectively, indicating that the plant might have sequestered the metal in the soil rather than accumulating it in the leaves. This was evident in the presentation of the metal sequestration factor of over 70 % irrespective of the nature of the metal. Microbial count of soil before and after contamination with lead nitrate was 19000 and 4000 cfu/g indicating a reduction. The study therefore revealed that Eleusine indica is a high efficient plant in sequestering lead in polluted soil.

XRD and UV-Vis Spectroscopic Studies of Lead Tin Sulphide (PbSnS) Thin Films

The effects of deposition cycles on the structural and optical properties of lead tin sulphide (PbSnS) thin films have been described. Successive ionic layer adsorption and reaction (SILAR) method was used to deposit the ternary material on soda-lime substrates. In the present work, the PbSnS films were grown using lead nitrate, tin chloride dehydrate and thioacetamide solutions as sources of Pb, Sn and S, respectively. XRD measurements revealed that the deposited films were polycrystalline in nature with strong adherent to the substrates. The transmittance was found to be high in the near infrared regions of the electromagnetic radiation and, also increased with deposition cycles. The band gap energy was found to vary from 1.70 to 1.75 eV for 10 and 35 deposition cycles. The study indicates that SILAR is an excellent method in depositing good quality films for device applications. HIGHLIGHTS SILAR is an excellent technique for depositing thin films of lead tin sulphide (PbSnS) Deposition cycles influences the XRD and optical properties of PbSnS thin films PbSnS thin films are useful for solar cell fabrications The band gaps of the PbSnS varies from 1.70 to 1.75 eV with deposition cycles

Synthesis and Characterization of Lead Dibutyl Dithiophosphate Nanoparticles

We examined the interaction of aqueous solutions of lead nitrate and sodium dibutyl dithiophosphate and showed the formation nanoparticles of lead dibutyl dithiophosphate. The effect of reaction parameters on the synthesis of nanoparticles was studied and the optimal conditions for the formation of their stable hydrosols were determined. The obtained products were investigated by methods of optical spectroscopy, dynamic light scattering. The average size of 15–20 nm, but due to the low surface charge, they are combined into larger aggregates. The UV‑vis spectra has absorption maximum at about 320 nm. TEM micrographs and Pb 2p, S2p XAS spectra revealed a composition and structure of the particles. These nanoparticles can play an important role in the flotation of sulfide minerals of nonferrous metals