Narrow Results

The chapter deals with some important aspects of the relationship of lithium and nickel with the ecosystem, which consists mainly of soil, water, plants and air. Some aspects of lithium and nickel use in the energy industry are also mentioned. We begin by considering the fact that the metallic elements lithium and nickel, either alone or in the form of their chemical compounds, are currently considered potential energy materials whose applicability is increasing with the transition to the mass use of electricity and batteries for powering motor vehicles. Both lithium and nickel are commonly found in nature. Even in relatively low concentrations, their presence is very dangerous or even toxic to some animals and biological organisms. On the other hand, certain plants and animals are a natural part of ecosystems and are unable to survive with-out their presence because they are vital to them. This contradiction and its implications form the main content of this chapter. The most significant effects of lithium and nickel in the environment, particularly in soil, water and plant systems, are presented. The interconnectedness between soil, water and plants is shown in relation to each other. Some of the analytical methods used for the detection of lithium and nickel are also given. In addition, some specific results are presented, which are not intended to specify particular locations in the field, but rather to highlight the ability of researchers to monitor the presence of lithium and nickel in the environment and to create conditions for their removal and possible reuse.

Lithium (Li) and nickel (Ni) are two of the most widely used metals in various industrial applications. Since they are available for plants’ uptake from the soil, excessive plant exposure to high doses of both metals may be tolerable or not for accumulating species and sensitive species, respectively. Many plants adopt a number of powerful detoxification techniques in their fight for survival. Among them, the antioxidant defence system is a crucial mechanism that helps plants cope with toxic metals, including Li and Ni. Understanding the different approaches that plants use to activate this system can provide insights into how we can improve plant resilience and protect them from environmental stressors. Besides the natural endogenously reacting antioxidant system in the plant’s own body, exogenously applied antioxidants have proven to be effective in mitigating the negative effects of the aforementioned metals. Herein, we review the traditional as well as recent advances used in overcoming the toxicity of Li and Ni to plants.

Human-induced environmental pollution, which has emerged with the increasing population in recent years, has become a global threat. One of the consequences of its rapid and destructive effects is that heavy metals, such as lithium (Li) and nickel (Ni), threaten soil and plant health, and their presence in soil and water poses a risk to both human health and environmental well-being. The purpose of this chapter is to explore the importance of bioremediation in removing Li and Ni from soil and water by investigating various research studies and approaches. Bioremediation is a solution that utilises microorganisms to remove heavy metals by converting them into less toxic forms. Therefore, it is important to carefully select the appropriate microorganisms and optimise the bioremediation conditions to achieve the best results. Moreover, the effectiveness of these techniques depends on various factors, such as the concentration of Li or Ni in the soil, the duration of the remediation process and the environmental conditions.

A detailed knowledge and recent advancements on the sources, speciation, toxicity and chemistry of nickel and its different compounds are discussed in this chapter. Nickel is an essential micronutrient for plant growth, and it is also a component of the enzyme urease, which plays a role in nitrogen metabolism in higher plants. Nickel and nickel compounds are also important for several biological processes in animals and soil/water microbes, and they have many industrial and commercial uses. Nickel is a known heavy transition metal and is found at very low levels in the environment. The vast industrial use of nickel leads to widespread environmental pollution. Higher levels of nickel can affect the photosynthetic function and transpiration of higher plants; it reduces seed germination, root and shoot growth, biomass accumulation and final production. Moreover, nickel toxicity leads to chlorosis and necrosis and may cause oxidative damage in plants. In addition, nickel toxicity degrades soil fertility, which may reduce crop production in the near future. The limited knowledge regarding the mechanisms of nickel tolerance in plants further highlights this fact. Furthermore, it causes many chronic diseases in humans, including allergy, cardiovascular and kidney diseases, lung fibrosis and lung and nasal cancers. The molecular mechanisms of nickel-induced toxicity, which cause the above diseases in humans, are still unknown. Mitochondrial dysfunctions and oxidative stress are mainly considered to play a crucial role in inducing toxicity from this metal. Therefore, we should pay attention in future research to find approachable and prominent ways of minimising the entry of nickel into our environment.

The chapter summarises some essential features and findings related to the toxicities of lithium (Li) and nickel (Ni), which are always present in trace concentrations in food and the environment. These metal elements occur almost everywhere in nature, including in soils, rocks and the atmosphere. Therefore, due attention should be paid to their presence in various substances, including food, water and air. These materials can enter the human body through ingestion of food, drinking water and other routes, such as inhalation and skin penetration. The occurrence of Li/Ni in the environment has increased tremendously recently due to some human activities, especially specific technological processes, which have resulted in an increased presence of these elements in various products and goods. Recently, Li and Ni are gradually being used as main components in Li-ion and NiCd batteries. The first type of battery is mainly used in electric cars, while the less powerful NiCd batteries are primarily used in portable electronic devices and toys.

In addition, the chapter discusses the specific forms of toxicity of these metal elements and their occurrence in some foods. The processes and pathways by which these elements can enter the human organism are also described. They can have severely harmful effects at certain excessive concentrations and amounts. Because of these detrimental impacts, Li and Ni levels should be monitored to enable intervention when their presence exceeds regulatory limits or recommendations. Based on the results of such measurements, effective control mechanisms can then be implemented to minimise their effects on human health, including introducing appropriate measures to protect workers who come into contact with these elements in the workplace. This chapter also describes the actions necessary to regulate these elements’ presence and impose adequate controlling mechanisms and preparations, including those to respond effectively to possible emergencies.

The current demand for more sustainable catalytic processes has seen a clear shift from the classical noble-metal-based catalysts to cheaper and abundant metals. The focus on earth-abundant transition-metal-based catalysts has been marred by synthetic and characterization challenges but is ultimately achieving the desired catalytic results. To extract the catalytic potential of earth-abundant transition-metal-based complexes, great care concerning the design of the supporting ligands is required. Under certain conditions, monoanionic bidentate chelates present a good strategy to tackle those goals. The 2-iminopyrrolyl framework is a good example of that: Its huge electronic and steric tuning potential has paved the way for diverse coordination chemistries of first-row transition metals, from manganese to copper. With such metal complexes in hand, several catalytic applications have been studied, namely polymerization, hydrofunctionalization and click chemistry. This chapter features the main catalytic achievements of complexes of earth-abundant metals bearing 2-iminopyrrolyl ligands and their respective mechanistic insights and structure–reactivity relationships.

The catalytic functionalization of C–H, C–OH and C–C bonds belongs to the most important processes in nature and the industry. In nature, this process occurs via involvement of enzymes, effectively and selectively, usually with very high turnover numbers. The pivotal role in enzymatic activity is played by the metal center cofactors, which involve several bioavailable transition metals, such as, iron, copper, manganese and zinc. In the industry, bond functionalization requires the presence of metal catalysts; therefore, a bio-inspired design of metal catalysts is a challenging approach. The recent advances in the catalysis of industrially important reactions, namely the oxidation and hydrocarboxylation of alkanes, the oxidation of alcohols and C–C coupling are reported. Convenient, environmentally friendly methods are presented, and the role and efficacy of the various transition-metal (iron, copper, zinc, manganese, nickel, vanadium, palladium and cobalt) catalysts are explored.

La_2−xSr_xNiO₄ shows a maximum in the c/a ratio around x = 0.6 up to which composition the concentration of holes is equal to that expected theoretically. The material becomes a degenerate semiconductor above a certain temperature up to x = 0.8, but is metallic at room temperature when x ≥ 1.0. All the compositions with x ≥ 0.05 are paramagnetic in the 15 - 300K range. Based on these measurements, an electronic phase diagram is tentatively proposed. It is noteworthy that the antiferromagnetic order disappears at low doping levels in both La_2−xSr_xNiO₄ and La_2−xSr_xCuO₄, but metallicity is seen at 300K only at a much higher x value in the former system.

The central nervous system (CNS) is partially protected from circulating toxicants by the blood-brain barrier. However, for xenobiotics which are excluded from the CNS the olfactory pathway provides an alternative route of passage into the brain. Thus, in the olfactory epithelium the primary olfactory neurons have dendrites in contact with the nasal lumen and axons which project to the olfactory bulbs. Materials which come into contact with the olfactory epithelium may be taken up in the primary olfactory neurons and transported to the olfactory bulbs and even further into other areas of the brain. The article deals with the uptake and transport of metals in the olfactory system. Metals discussed are mainly manganese, cadmium, nickel, aluminum, zinc, cobalt and mercury. Among these metals manganese has a unique capacity to be taken up via the olfactory pathway. Thus, following transport along the primary olfactory neurons to the olfactory bulbs manganese continues via secondary and tertiary olfactory neurons and further connections to all parts of the brain and even into the spinal cord. Cadmium is transported along the axons of the primary olfactory neurons to the olfactory bulb, but this metal appears unable to leave the terminal arborizations of the axons in the glomeruli of the bulb. Studies with nickel, zinc, cobalt and mercury indicate that these metals are transported along the primary olfactory neurons and accumulated in the olfactory nerve layer and the glomerulular layer of the bulbs. In addition, low levels of these metals leave the terminations of the primary olfactory neurons. There is evidence that mercury also may undergo axonal transport in the primary olfactory neurons following uptake in these neurons from the systemic circulation. This may be a part of a more general ability of mercury to be taken up in neurons with access to the systemic circulation and reach the CNS via transport in these neurons. There is evidence that aluminum is transported along the olfactory pathway, but the fate of this metal in the olfactory system is not yet known in detail. The olfactory pathway is a route by which metals may circumvent the blood-brain barrier and reach the central nervous system. The possibility that uptake and transport of metals in the olfactory pathways may induce olfactory dysfunction and neurotoxicity should be taken into account in risk assessments of occupational metal exposure via inhalation.

Salmonella typhimurium was cultured either in minimal or in enriched medium in the presence of increasing concentrations of Ni²⁺, Cd²⁺, Hg²⁺ and exhibited a much higher sensitivity to Hg²⁺ than to the other two metal ions. After 24 h growth in minimal medium the yield decreased by 50% in the presence of 0.26 mM Ni²⁺ and by 60% in the presence of either 0.08 mM Cd²⁺ or 0.0008 mM Hg²⁺. After growth in enriched medium, the yield decreased by 80% in the presence of 15 mM Ni²⁺ or 5 mM Cd²⁺ and by 65% in the presence of 0.03 mM Hg²⁺. Cytochromes were used as a probe to investigate the effect of metals on membrane proteins. Increasing metal concentrations led to increasing reductions in the amount of all cytochromes (b₅₆₀, b₅₉₅ and d) although to various extends, depending on the metal and on the cytochrome. At metal concentrations that drastically diminished the cell yield, cytochrome b₅₉₅ was the most affected in the presence of Ni²⁺ or Cd²⁺, while cytochrome d was the most affected in the presence of Hg²⁺. Results indicated that Hg²⁺ distinguished itself from Cd²⁺ and Ni²⁺ by the concentration range tolerated by the bacterium as well as by the effect observed on the cytochromes.

A finite rank separable approximation for the quasiparticle random phase approximation with Skyrme interactions is applied for the case of charge-exchange nuclear modes. The couplings between one- and two-phonon terms in the wave functions are taken into account. First, we check that the approximation reproduces reasonably well the full charge-exchange RPA results for the spin-dipole resonances in ¹³²Sn. As an illustration of the method the phonon-phonon coupling effect on the β-decay half-live of ⁷⁸Ni is considered.