Examples Of Heavy Metals Research Articles

The role of soil elemental forms in the soil-plant migration system: An example of heavy metals in Epimedium production areas

Investigating the heavy metal content and migration behavior in the soil and plant system of Epimedium origin is crucial for ensuring the safety and sustainable development of this valuable medicinal plant. The concentration of heavy metals in the soil of Epimedium was found to be highest in the residuel form (RS) and lowest in the water-soluble form (WS). Among the different parts of the Epimedium plant, leaves showed the highest content of Cr, Ni, Cu, As, and Pb with average contents of 0.02 mg.kg−1, 0.01 mg.kg−1, 0.11 mg.kg−1, 0.16 mg.kg−1, and 0.01 mg.kg−1, respectively, and roots showed the highest content of Zn with average contents of 0.30 mg.kg−1. The results of correlation analysis and linear fitting showed significant correlation and better linear fitting results between different parts of Epimedium (roots, stems and leaves) and various forms of heavy metals in soil. Among them, Zn (ion-exchange form) and Zn (leaf) showed the best fit with R2 reaching 0.74. Results from random forest modeling indicated that the forms of heavy metals in soil, such as bound form, ion exchange form, and strong organic bound form, significantly influenced the distribution of heavy metals in roots, stems, and leaves of Epimedium. Overall, besides the readily available heavy metals in soil, other forms of heavy metals also play a critical role in the soil-plant migration system.

Mitigating the Adverse Effects of Lead and Cadmium Heavy Metals-Induced Oxidative Stress by Phytogenic Compounds in Poultry

Environmental pollution has increased over the past few decades, posing serious risks to all biological systems, including the poultry sector. Oxidative stress in chickens caused by dietary, environmental, and pathological variables influences how well chickens perform as well as the quality of meat and eggs. Lead (Pb) and cadmium (Cd) are two examples of heavy metals that are harmful for chicken health. They can cause oxidative stress by increasing the production of reactive oxygen species (ROS) and reactive nitrogen species (RNS) and blocking antioxidants from protecting cells from increased amounts of free radicals. The oxidative state of heavy metals, their interactions with endogenous antioxidants, and chemical processes all affect how hazardous they are to the body. Today, scientists have investigated and applied a variety of nutritional tactics to lessen the harmful effects of oxidative stress on animal health brought on by heavy metals. Researchers have recently become interested in the chemicals because of their chelating and growth-stimulating functions, as well as the antioxidant qualities of useful plant components. The deleterious consequences of oxidative stress induced by two heavy metals on chickens is discussed in this review, along with phytogenic use as a potential intervention strategy to lessen these effects and maintain the redox equilibrium in poultry.

Toxicity Test of Copper (Cu) and Chromium (Cr) on the Growth of Mung Bean (Vigna radiata L.) Sprouts

Industries that are growing rapidly contribute a big role in environmental pollution, one of which is the production of heavy metal waste. One example of heavy metals that are toxic when present in large quantities is Copper (Cu) and Chromium (Cr). The purpose of this experiment is to test the toxicity of the two types of heavy metals Cu and Cr against the seed growth of the Vigna radiata L. plant, find out the type of metal that gives the highest percentage of inhibition to the growth of V. radiata L., and find out the relationship between the two types of heavy metals. The method to determine the level of toxicity and the relationship between the two metals can be known by toxicity tests which include preliminary tests, actual tests and mixed tests on the seeds of V. radiata L. while data analysis is carried out by linear regression and the data is presented in the form of tables and graphs. Preliminary test to determine the ideal range of toxicity concentrations to be continued with the actual test with the addition of Cu and Cr metal toxins to the seeds of V. radiata L. The results of the study on the actual test showed that the IC50 of Cu metal was 127.4 ppm while the IC50 of Cr metal was 615.23 ppm with Cu metal having a more significant negative impact than Cr. In the mixed test, it showed that Cu metal IC50 was 247.5 ppm while Cr metal IC50 was 579.85 ppm with the highest inhibition value at Cu:Cr concentration of 90:10. The toxicant relationship of Cu and Cr based on the additive index is the additive (value S = 0).

A pipeline for monitoring water pollution: The example of heavy metals in Lombardy waters

Time-dependent geolocalized analysis of pollution data allows to better understand their dynamics over time and could suggest strategies to restore a good ecological status of contaminated area. This research analyzes concentrations of pollutants in surface waters and groundwater monitored by the Regional Environment Protection Agency of Lombardy from 2017 to 2020. Lombardy is one of the richest and populous region of Europe, providing an interesting example of the impact of environmental pollutants due to anthropogenic and industrial activities, not only for Italy but also for all Europe. Results show that groundwater displays more sites with heavy metals above the legal limit with respect to surface waters, including As, Ni, Cr and Zn. Furthermore, the spatio-temporal analysis of the data clearly shows that the introduction of more restrictive laws is a proper policy to improve the ecological status of the water.

A microengineered biomimetic model of the placental barrier to study environmental exposures during pregnancy

Exposure to toxic heavy metals contributes to the development of pregnancy complications that can adversely affect fetal development. Despite increasing evidence suggesting the negative health impact of heavy metals, investigating their adverse effects in the context of human pregnancy remains a major challenge due to the difficulty of human subject research and the limited capacity of animal models to properly represent the anatomy and function of the human reproductive system. Motivated by problem, here we describe a microengineered in vitro model designed to reverse engineer the maternal-fetal interface in the human placenta. This biomimetic system enables advanced capabilities to grow human trophoblast cells and fetal vascular endothelial cells in a physiological spatial arrangement and dynamic culture conditions to engineer the placental barrier in vitro that can emulate regulated material transport between maternal and fetal circulations. Using cadmium (CdCl2 ) as a representative example of heavy metals, we investigate whether and how this environmental chemical affects the human placental barrier and its physiological function as a gatekeeper. Our study also examines the role of membrane transporters in the maternal-to-fetal transfer of cadmium to provide insights into efflux transporter-medicated protection against environmental exposures during pregnancy.We used soft lithography to construct a compartmentalized elastomeric device consisting of two overlapping chambers separated by a thin semipermeable membrane. After sterilization and surface coating with extracellular matrix protein, the device was seeded with BeWo b30 human trophoblast cells and primary human villous endothelial cells on the opposite sides of the membrane. The bi-layer tissue was then cultured under perfusion conditions by using syringe pumps connected to each chamber. To mimic the physiological process of placental development, we treated the trophoblast cell layer in the maternal chamber with forskolin (50 µM) to induce syncytialization.Our microengineered model of the human placental barrier formed a tight barrier (evaluated by expression of E-cadherin and VE-cadherin), secreted the pregnancy hormone human chorionic gonadotropin beta (hCGβ), and supported physiological maternal-to-fetal transport of glucose. Following CdCl2 treatment (0.5-50 µM), we observed concentration-dependent deleterious responses of the maternal and fetal tissues as demonstrated by reduced cell viability and placental hormone secretion, compromised barrier function, and increased secretion of proinflammatory cytokines. The results also indicated upregulated expression of metallothioneins IA and IIA (MT-IA/IIA) metal binding proteins.The placenta-on-a-chip is an innovative and translational in vitro platform for the study of environmental chemical toxicity in the human placenta. With further improvements, this technology may advance our ability to model, interrogate, and predict the potential of xenobiotics to disrupt placentation and maintenance of human pregnancy.

Contamination of groundwater with heavy metals and its impact on soil and plants – A review

Heavy metals are naturally occurring compound elements that exist in many forms in the environment and the Earth’s biosphere. It is any metallic chemical element with a high density that is hazardous or dangerous at tiny concentrations. Mercury (Hg), lead (Pb), arsenic (As), copper (Cu), and nickel are examples of heavy metals (Ni). These elements are mostly found in water and soil. These natural elements are created by the weathering of parent materials and should occur as a result of human actions. Heavy metal contamination is a severe issue due to its toxicity and ease of propagation in the biotic world. It also has serious consequences for animals, soils, crops, and humans. In this work, we will primarily examine heavy metal contamination in groundwater and its impact on soil. These elements are beneficial to both plants and humans, but exceeding the safe limit generates pollution and has a negative impact on the ecosystem. Heavy metal contamination in soil degrades land and poses a risk to soil and plant growth.

Study of photodegradation performance and ability of lead removal of green synthesised maghemite nanoparticles

ABSTRACT Today, water pollutants such as heavy metals and dyes are serious dangers to nature. Metals such as lead, chromium, mercury, and arsenic are examples of heavy metals which are toxic to living things, even sometimes at the lowest concentrations. Magnetic nanoparticles are considerable compounds because of their advantages such as high efficiency, fast recovery capability, high surface area, easy transportation, and inexpensiveness. We presented an easy and eco-friendly method for the synthesis of iron oxide nanoparticles using Ziziphus jujuba extract. In order to determine the physical, chemical and optical properties of the synthesised samples, Fourier-transform infrared (FT-IR), powder X-ray diffraction (PXRD), vibrating sample magnetometer (VSM), field emission scanning electron microscope (FESEM), energy dispersive X-ray (EDX), transmission electron microscopy (TEM), and Raman analyses were deployed. The PXRD results showed that the synthesised nanoparticles have a maghemite form of (γ-Fe2O3). The results showed that the synthesised nanoparticles were capable of removing 96% of lead at pH = 7 and 1 mg/L loading of nanoparticles. Adsorption isotherms of lead on nanoparticles as adsorbents were determined based on Freundlich and Langmuir adsorption isotherm models. The results showed that the best model of adsorption isotherm was Langmuir model. The photocatalytic activity of γ-Fe2O3 NPs was studied on methylene blue (MB) dye; as a result, MB at pH = 7 and 1 gr dosage of γ-Fe2O3 had the highest removal percentage (92.8%) during 160 minutes using γ-Fe2O3 which calcined at 400 °C. The reusability results showed that after four cycles of using the γ-Fe2O3-400, the obtained degradation of methylene blue was about 87.1%. Therefore, synthesised γ-Fe2O3 NPs can be a good alternative for removing heavy metals and industrial dyes from contaminated waters.

Performance Evaluation of Polyethersulfone Membranes for Competitive Removal of Cd2+, Co2+, and Pb2+ Ions from Simulated Groundwater

This paper presents studying the performance of three types of polyethersulfone (PES) membrane for the simultaneous removal of Co2+ ions, Cd2+ ions, and Pb2+ ions from binary and ternary aqueous solutions. Co2+ ions, Cd2+ ions, and Pb2+ ions with two different initial concentrations (e.g., 10 and 50 ppm) were selected as examples of heavy metals that contaminate the groundwater as a result of geological and human activities. This study investigated the effect of types of PES membrane and metal ions concentration on the separation process. For the binary aqueous solutions, the permeation flux of the PES2 membranes was higher for the separation process of solutions containing 50 ppm of Cd2+ ions and 10 ppm of Co2+ ions (24.7 L/m2·h) and Pb2+ ions (23.7 L/m2·h). All the metals in the binary solutions had high rejection when their initial concentration was lower than the initial concentration of the other metal present in the same solution. Using PES2, the maximum rejection of Cd2+ ions was 61.3% when the initial concentrations were 50 ppm Pb2+ ions: 10 ppm Cd2+ ions and 55.4% for Pb2+ ions when the initial concentrations were 10 ppm Pb2+ ions: 50 ppm Cd2+ ions. For the ternary aqueous solutions, the rejection and the permeation flux of the PES membranes increased with decreasing the heavy metal initial concentration. Using PES2, the maximum permeation flux was 21.6 L/m2·h when the initial concentration of the metals was 10 ppm; and the maximum rejection of the metals obtained at initial concentration of 10 ppm was 50.5% for Co2+ ions, 48.3% for Cd2+ ions, and 40% for Pb2+ ions. The results of the filtration process using PES2 of simulated contaminated-groundwater indicated the efficient treatment of groundwater containing Co2+, Cd2+, and Pb2+ ions.

Heavy Metals Toxicity and the Environment Protection

Pollution of environment is one of the most horrible ecological crisis to which we are subjected today. One of the main sources of pollution in the environments is metallic compounds. Metals and metalloids have long been mined and used in numerous applications. This has led to a significant increase of metal pollutions. Metals can accumulate in all environmental matrices at either high or trace levels of concentration. Heavy metals are naturally occurring elements that have a high atomic weight and a density. Therefore amount of various kinds of metals are present in soil, plants, air, lakes, animals, oceanic regions, even in foodstuffs and human beings. Their widespread distribution, especially heavy metals, became serious problems because of their toxicities for animals, human health and the environment. Their toxicity of heavy metals depends on several factors including the dose, route of exposure and chemical species, as well as the age, gender, genetics and nutritional status of exposed individuals. Because of their high degree of toxicity, lead, cadmium, chromium, zinc, nickel, arsenic and mercury rank among the priority metals that are of public health significance. Metals generally enter in the ecosystem in a relatively non-toxic form and generally become intrinsic components of the environment in such a way that it is difficult to remove them from the environment. Some of them are converted into toxic forms through the environmental reactions involving various micro-organisms and non-biological pathways. For example, methylated compounds like dimethyl mercury, (CH3)2Hg, are more toxic than their inorganic forms. In the present investigation more attention has been given to heavy metals like lead, cadmium, nickel and zinc. Although, the term “heavy metals” refer to any metallic element that has a relatively high density and is toxic or poisonous at low concentrations. Examples of heavy metals include Pb, Cd, Hg, As, Cr and Ti etc. This review provides an analysis of their environmental occurrence, production and use, potential for human exposure and molecular mechanisms of toxicity, genotoxicity and carcinogenicity.

Removal of some heavy metals and fungicides from aqueous solutions using nano-hydroxyapatite, nano-bentonite and nanocomposite

A batch adsorption experiments were carried out to study the role of nanoparticles and nanocomposite on removal of some heavy metals and fungicides from aqueous solution. Nano-Hydroxyapatite (n-HAP), Nano-Bentonite (n-Bo) and Bentonite-hydroxyapatite nanocomposite (B-HAP NC) evaluated for the removal of some heavy metals and fungicides. The nanoparticles and nanocomposite were characterized by TEM, SEM and AFM, X-ray powder diffraction (XRD) and BET surface area. The batch adsorption was done using nanoparticles with Pb2+ and Ni2+ as example of heavy metals with concentrations up to 25 mgL−1. Also, the adsorption experiment was conducted using nano-particles (n-HAP, n-Bo and B-HAP NC) with fungicides Stop Feng and Eurozole with concentrations 20 to 200 μg L−1. Langmuir and Freundlich isotherm equations were employed to study the adsorption. The adsorption kinetics were conducted metal ion (Pb2+ and Ni2+) with residence time. The results indicated the maximum adsorption capacity of Ni+2 was occurred on (n-HAP). While that maximum adsorption capacity of Pb2+ was occurred on (B-HAP NC). The rate of Ni+2 removal was found to be very rapid during the initial 60 min. The adsorption of Pb+2 by the n-HAP and (B-HAP NC) was a slow increase with time, it did not bring any remarkable effect. Also, the efficiency of adsorbent compounds used to remove the residue of fungicides Stop Feng and Eurozole shown the highest removal rates obtained with used nano-hydroxyapatite followed by bentonite-hydroxyapatitenanocomposite and nano-bentonite, respectively. The current results are very useful in the treatment of wastewater and the removal of heavy metals and fungicides, consequently making them suitable for agricultural purposes.

Adapted methodology for comprehensive contamination assessment of bottom sediments on the content of various forms of heavy metals

As a result of long-term studies of bottom sediments of lakes, rivers, ponds and reservoirs of the Republic of Tatarstan, considerable factual material has been accumulated, which enabled the translation of quantitative estimates into qualitative characteristics. This necessitated a comprehensive assessment and generalization of the exceedance of the thresholds set for all metals, similarly to the specific combinatorial water pollution index (SCWPI). At the same time, the authors emphasize the features of such a comprehensive assessment of bottom sediments, and also suggest methods and algorithms for solving emerging problems. We use the method of frequency characteristics of data series of metal content (Cd, Pb, Co, Cu, Ni, Zn, Cr, Mn, Fe) in bottom sediments, score the relevant characteristics, generalize the point estimates and bring them to the appropriate classes of purity. As a result, a method for the integrated assessment of contamination of bottom sediments was developed and tested, which solves the problem of the integral assessment of the quality of bottom sediments in terms of a complex of pollutants using the example of heavy metals. The method is based on the approach of the SCWPI. Therefore, its results are comparable to combinatorial assessments of water quality, which will allow deriving a uniform assessment of the water body as a whole.

Polymeric Composites with Embedded Nanocrystalline Cellulose for the Removal of Iron(II) from Contaminated Water.

The exponential increase in heavy metal usage for industrial applications has led to the limited supply of clean water for human needs. Iron is one of the examples of heavy metals, which is responsible for an unpleasant taste of water and its discoloration, and is also associated with elevated health risks if it persists in drinking water for a prolonged period of time. The adsorption of a soluble form of iron (Fe2+) from water resources is generally accomplished in the presence of natural or synthetic polymers or nanoparticles, followed by their filtration from treated water. The self-assembly of these colloidal carriers into macroarchitectures can help in achieving the facile removal of metal-chelated materials from treated water and hence can reduce the cost and improve the efficiency of the water purification process. In this study, we aim to develop a facile one-pot strategy for the synthesis of polymeric composites with embedded nanocrystalline cellulose (NCC) for the chelation of iron(II) from contaminated water. The synthesis of the polymeric composites with embedded nanoparticles was achieved by the facile coating of ionic monomers on the surface of NCC, followed by their polymerization, crosslinking, and self-assembly in the form of three-dimensional architectures at room temperature. The composites prepared were analyzed for their physiochemical properties, antifouling properties, and for their iron(II)-chelation efficacies in vitro. The results indicate that the embedded-NCC polymeric composites have antifouling properties and exhibit superior iron(II)-chelation properties at both acidic and basic conditions.

A review on heavy metals biosorption in the environment

Heavy metal refers to any metallic chemical element that has a relatively high density and is toxic or poisonous at low concentrations. Examples of heavy metals include mercury (Hg), cadmium (Cd), arsenic (As), chromium (Cr), thallium (Tl) and lead (Pb). Little amounts of some heavy metals are needed by living organisms, however excessive levels of these metals can be harmful to the organisms due to their level of toxicity and accumulation behaviour. Different methods such as electrodeposition, electrocoagulation and nanofiltration system have been used to decontaminate the environment from adverse effect of these pollutants yet most of the methods used are ineffective. Biosorption is the removal of organic and inorganic substances from solution by biological material. Cheap biosorbents for the removal of metals are bacteria, fungi, algae, plants, industrial wastes and agricultural wastes. There are many mechanisms involved in biosorption some of which are not fully understood, examples are precipitation, ion exchange, complexation and adsorption. The efficiency of biosorption depends on many factors such as, temperature, characteristics of the biomass, pH, surface area to volume ratio, metal affinity to the biosorbent, concentration and characteristics of the biomass. Compared to other methods biosorption is operated over a wide range of physiochemical conditions and it uses naturally rich renewable biomaterials that can be cheaply produced. However, the potential for biological process improvement (for example through genetic engineering of cells) is restricted because cells are not metabolizing. Biosorption is in its developmental stages and further improvement in both performance and costs can be expected in future.

SYNTHESIZED CHITOSAN/ IRON OXIDE NANOCOMPOSITE AND SHRIMP SHELL IN REMOVAL OF NICKEL, CADMIUM AND LEAD FROM AQUEOUS SOLUTION

In this study, an easy synthesized method for preparation of chitosan/iron oxide nanocomposite as a bio-sorbent has been applied. Analytical techniques such as Fourier transform infrared spectroscopy, X-ray diffraction; Field emission scanning electron microscopy and transmission electron microscopy were utilized to survey of morphological structure and the functional groups characterization. The histogram of frequency of particle size confirmed that medium size of the synthesized nanoparticles was 50 nm. Beside the obtained nanocomposite, application of chitosan as the precursor and shrimp shell as natural chitin and a natural polymer were assessed as adsorbents for decontamination of Ni2+, Cd2+ and Pb2+ as examples of heavy metals from drinking water. Batch studies were performed for adsorption experiments by changing variables such as pH, contact time and adsorbent dose. Based on the experimental sorption capacities, 58, 202 and 12 mg of Ni, Cd and Pb per g of Chitosan-Fe2O3 nanocomposite as adsorbent respectively, confirm that combination of Fe2O3 nanoparticles with chitosan makes a more efficient adsorbent than chitosan and chitin. Adsorbents in uptake of the mentioned heavy metals are in the order of Chitosan-Fe2O3 nanocomposite > chitosan> chitin. In addition, the kinetics and isotherm investigations were surveyed. Moreover, it has been shown that the synthesized nanocomposite significantly reduces the amount of the mentioned ions from the real wastewater sample.

Genesis of the idea and definition of pedogeochemical barriers of heavy metals migration

The aims of this study were to consider the genesis’s idea «geochemical barriers» and to invite a definition for «pedogeochemical barriers» by example of heavy metals’ migration. Object of this study – scientific publications that show the results of heavy metals’ content and distribution in soils. The concept of geochemical barriers was formulated by A. I. Perelman in 1961. At first ideas of this concept have been used for: 1) ordering of the geochemical conditions at hypergenesis zone, 2) justification the concept of geochemical field; 3) mathematical modeling of geochemical processes, 4) effective mineral exploration. With the passage of time, this concept has become successfully implemented in lithology, hydrogeology, soil science, geochemistry environment. In the XXI century geochemical barriers used in the development of rehabilitation technology of contaminated lands and limit the spread of pollutants. The concept of geochemical barriers began to be used in soil science, through the work of V. A. Kovda (1972), A. A. Rode (1975), M. A. Glazovskaj (1988). Later, the list of researchers who used this idea in their works has increased significantly. However, these researchers: 1) was performed a mechanical transfer this idea from geochemistry to soil science, 2) use this idea mainly for environmental protection, 3) used exclusively of the geochemistry methodology and of the geochemistry classification schemes. As for soil science the best analogue of «geochemical barriers» should recognize the term «pedogeochemical barriers». An essence pedogeochemical barrier, in our opinion, is as follows. In hypergenesis zone the geochemical barriers act as «situational and contrast» phenomenon. In soil profile the pedogeochemical barriers act as «substation and reaction» phenomenon. We are supposed to that the soil profile is a multiaspect complex of pedogeochemical barriers. At that some of them can be localized within several soil horizons. At the same time, several such barriers can be located in one soil horizon. Therefore, in the refined form, a pedogeochemical barrier should be understood as part of the soil profile, where, as a result of the formation of special conditions for substitution-reaction interactions, the accumulation of certain chemical elements occurs. Designed by A. I. Perelman's doctrine of geochemical barriers has found a varied and successful application in geochemistry, geology, lithology, mineralogy, and in other contiguous sciences. At present, the ideas of this exercise are very important for a fundamental understanding of the biogeochemical functions of the pedosphere as the theoretical basis for preserving the biosphere and improving the soil in conditions of modern technogenesis. In our understanding, the pedogeochemical barrier is part of the soil profile, where, as a result of the formation of special conditions for substitution-reaction interactions, the accumulation of certain chemical elements occurs. In further studies it is expedient to consider: mechanisms of action, typology, parameters of pedogeochemical barriers, and also to analyze these parameters on the example of heavy metals in chernozems of ordinary and southern.

Application of dahlia-like molybdenum disulfide nanosheets for solid phase extraction of Co(II) in vegetable and water samples.

Recently, molybdenum disulfide has been attracted considerable attention due to its unique three layered structure. Adsorption sites with abundant electron density on edges and surfaces of MoS2 can adsorb different metal ions with no need to ligand and functionalization. In this study, dahlia-like MoS2 nanosheets were prepared by a simple hydrothermal method and characterized using different tools such as FESEM, TEM, EDX, XRD, DLS and zeta potential measurements. Then, they were applied for solid phase extraction of Co(II) as an example of heavy metals. Different factors (the pH, adsorbent amount, contact time, type of eluent, matrix and reusability) affecting the extraction process were studied. Under optimum conditions, the relative standard deviation, adsorption capacity and limit of detection were 2.3%, 80.0mgg-1 and 0.31μgL-1, respectively. The accuracy of the method was confirmed by analyzing the standard reference material (SRM 1640a) and spiked real samples.

Antioxidant effect of ginger to prevents lead-induced liver tissue apoptosis in rat.

Lead acetate is an example of heavy metals that for decades being known for its adverse effects on various body organs and systems such that their functions are compromised. In the present study, the ability of lead to adversely affect the liver tissue apoptosis was investigated. Ginger is source of antioxidants was administered orally to prevent the adverse effects of lead acetate. Thirty Wistar rats, randomised into 3 groups (n = 10), were used for this study. Animals in group (A) served as the control and were drinking distilled water. Animals in groups (B) and (C) were drinking 1% lead acetate. Group (C) animals were, in addition to drinking lead acetate, treated with 100 mg/kg/rat of ginger. All treatments were for 10 weeks. The obtained results showed that lead acetate caused a significant reduction in the liver weight, plasma superoxide dismutase and catalase activity, but a significant increase in plasma malondialdehyde concentration, using ginger cause to modified these harmful effects. These findings lead to the conclusion that ginger significantly decreased the adverse harmful effects of lead acetate exposure on the liver as well as lead acetate -induced oxidative stress. Key words: Apoptosis, ginger, lead acetate, liver, reactive oxygen species.

Determination of linear aliphatic aldehydes in heavy metal containing waters by high-performance liquid chromatography using 2,4-dinitrophenylhydrazine derivatization

A simple and sensitive method is described for the determination of picomolar amounts of C 1–C 9 linear aliphatic aldehydes in waters containing heavy metal ions. In this method, aldehydes were first derivatized with 2,4-dinitrophenylhydrazine (DNPH) at optimized pH 1.8 for 30 min and analyzed by HPLC with UV detector at 365 nm. Factors affecting the derivatization reaction of aldehydes and DNPH were investigated. Cupric ion, an example of heavy metals, is a common oxidative reagent, which may oxidize DNPH and greatly interfere with the determination of aldehydes. EDTA was used to effectively mask the interferences by heavy metal ions. The method detection limits for direct injection of derivatized most aldehydes except formaldehyde were of the order of 7–28 nM. The detection limit can be further lowered by using off-line C 18 adsorption cartridge enrichment. The recoveries of C 1–C 9 aldehydes were 93–115% with a relative standard deviation of 3.6–8.1% at the 0.1 μM level for aldehydes. The HPLC–DNPH method has been applied for determining aldehyde photoproducts from Cu(II)–amino acid complex systems.

Tomato ( Lycopersicon esculentum ) prevents lead-induced testicular toxicity

BACKGROUND:Lead, an example of heavy metals, has, for decades, being known for its adverse effects on various body organs and systems such that their functions are compromised.AIM:In the present study, the ability of lead to adversely affect the male reproductive system was investigated and tomato (Lycopersicon esculentum: Source of antioxidants) paste (TP) was administered orally to prevent the adverse effects of Pb.MATERIALS AND METHODS:Fifteen Sprague Dawley rats, randomised into three groups (n = 5), were used for this study. Animals in Group A served as the control and were drinking distilled water. Animals in Groups B and C were drinking 1% Pb (II) acetate (LA). Group C animals were, in addition to drinking LA, treated with 1.5 ml of TP/day. All treatments were for 8 weeks.STATISTICAL ANALYSIS USED:A Mann–Whitney U-test was used to analyse the results obtained.RESULTS:The obtained results showed that Pb caused a significant reduction in the testicular weight, sperm count, life–death ratio, sperm motility, normal sperm morphology, and plasma and tissue superoxide dismutase and catalase activity, but a significant increase in plasma and tissue malondialdehyde concentration. But, Pb did not cause any significant change in the serum testosterone level. TP, however, significantly reduced these adverse effects of Pb.CONCLUSION:These findings lead to the conclusion that TP significantly lowered the adverse effects of Pb exposure on the kidney as well as Pb-induced oxidative stress.

Adsorption kinetics and intraparticulate diffusivities of Hg, As and Pb ions on unmodified and thiolated coconut fiber

As, Hg and Pb are examples of heavy metals which are present in different types of industrial effluents responsible for environmental pollution. Their removal is traditionally made by chemical precipitation, ion-exchange and so on. However, this is expensive and not completely feasible to reduce their concentrations to the levels as low as required by the environmental legislation. Biosorption is a process in which solids of natural origin are employed for binding the heavy metal. It is a promising alternative method to treat industrial effluents, mainly because of its low cost and high metal binding capacity. The kinetics was studied for biosorption experiments using coconut fiber for As (III), Hg (II) and Pb (II) ions adsorption. The specific surface area and surface charge density of the coconut fiber are 1.186x10 25 (m 2 /g) and 5.39 x10 24 (meq/m 2 ), respectively. The maximum adsorption capacity was found to be the highest for Pb (II) followed by Hg (II) and As (III). The modification of the adsorbent by thiolation affected the adsorption capacity. Equilibrium sorption was reached for the metal ions at about 60 min. The equilibrium constant and free energy of the adsorption at 30 oC were calculated. The mechanism of sorption was found to obey the particle- diffusion model. The kinetic studies showed that the sorption rates could be described by both pseudo first-order and pseudo second-order models. The pseudo second-order model showed a better fit with a rate constant value of 1.16 x 10 -4 /min. for all three metal ions. Therefore, the results of this study show that coconut fiber, both modified and unmodified, is an efficient adsorbent for the removal of toxic and valuable metals from industrial effluents.