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Phytoremediation is a technology for remediation of contaminated soils. In this study, we used a submilli-PIXE camera to analyze plants and soils from a shooting range. Some heavy metals were rapidly and easily detected in these samples. Element dot-maps of the plant show Cu and Pb accumulated in the epidermis of subterranean stems and the venation of leaves. From these findings, it is possible to map the distribution of heavy metals and to detail their location in the plant, using the submilli-PIXE camera. PIXE analysis is an effective tool for undertaking phytoremediation research.

Pytoremediation using an arsenic hyperaccumulator, Petris vittata L., has generated an increasing interest worldwide due to both environmentally sound and cost effectiveness. However the mechanism of arsenic accumulation by this fern is not clear at this time. This study examined the uptake of arsenate (As(V)) and arsenite (As(III)) by a hydroponic culture of Pteris vittata using both in-air submilli-PIXE for different parts of the fern and in-air micro-PIXE for the tissue cells. These PIXE analysis systems used 3 MeV proton beams from a 4.5-MV single-ended Dynamitron accelerator at Tohoku University, Japan. The fern took up both arsenate and arsenite from hydroponic solutions which were spiked with 50 mg of arsenic per litter. Final amount of arsenic accumulation in the fern is 1,500 mg per kg (wet weight) of the plant biomass in arsenite treatment and 1,100 mg per kg in arsenate treatment. Arsenic accumulation was not observed at the root parts of the ferns. The in-vivo mapping of elements by submilli-PIXE analyses on the fern laminas showed the arsenic accumulation in the edges of a pinna. The micro-PIXE analyses revealed arsenic maps homogeneously distributed in cells of the lamina, stem and rhizome of the fern. These results indicate that arsenic, both arsenate and arsenite in a contaminated medium are translocated quickly from roots to fronds of Pteris vittata, and distributes homogeneously into tissue cells of the fern laminas.

Pteris vittata is a fern reported to be an arsenic hyper-accumulator. To develop the practical application of the fern to a phytoremediation technique, it is necessary to explicate the effective accumulation mechanism. In this study, the arsenic distribution and the elemental correlation in the cellular level were examined in the fronds supplied with arsenate and arsenite separately via xylem vessel using an in-air micro-PIXE system at Tohoku University. The difference in transportation rate between arsenate and arsenite as well as the translocation of elements necessary for plant metabolism was revealed in different tissues of the fronds accumulating arsenic in high concentration. Hence, the in-air micro-PIXE analysis is an effective measure for undertaking phytoremediation research of hyper-accumulator plants.

This article exhibits the research into environmental issues in Malaysia.

Lithium (Li) is taking frontline in electronic items and vehicles world-wide. Great uses of Li draw attention and are in demand everywhere, hence production also increases daily. The major problem with Li is its toxicity, which eventually enters human and animal life via the food chain. It is non-degradable and has a long shelf-life — it can sustain anywhere for a more extended period but causes much toxicity to the host. Removal of Li is a big challenge, and expensive methods need to be employed. Thus, environmentalists came up with a sustainable approach called phytoremediation — the use of plants to clean up hazardous contaminants. In this method, the plant, or hyperaccumulator, grows on Li-contaminated soils and absorbs a higher concentration of Li without compromising its own immunity. In this chapter, we reviewed the source, pathway of contamination and remediation of Li using plant species.

The search for environmentally friendly practices and new technologies in order to reduce the ecological impact associated with nickel disposal and pollution remains open. In this sense, phytoremediation stands out as a high-efficiency, eco-friendly green technology for removing pollution from contaminated soil, water and air. It is a form of bioremediation and an economical and sustainable alternative to traditional chemical and physical pollution remediation methods. High metal bioaccumulation efficiency and tolerance are requisites for plants employed in phytoremediation techniques; thus, investigating new aquatic plants with such characteristics is a priority. The antioxidant defence system plays a significant role in providing resistance to plants by protecting labile macromolecules against the attack of free radicals. This ability made possible the use of aquatic plants in technological applications for the restoration of contaminated sediments, solid wastes and organic contaminants. Accordingly, results have demonstrated that Lemna gibba and Ceratophyllum demersum would have the capacity to tolerate and, therefore, resist nickel stress. APX would be a more efficient enzyme in the detoxification of hydrogen peroxide, as its activity was stimulated at higher exposure concentrations. This reinforces the proposal of selecting APX as a good biomarker for the evaluation of the welfare of plants and growth performance. It is important to keep in mind that plant stress tolerance may be improved by the enhancement of the levels of antioxidant enzymes, in particular those related to the application of aquatic plants in the phytoremediation of nickel from wastewaters and industrial effluents.

Many manufacturing items require specific elements, including, for example, low-carbon technologies such as wind turbines, electric cars, and catalytic converters. The growing global population and aspirations for a better life have raised concerns about the security and accessibility of valuable elements. These economically important metals need appr priate, environment-friendly recovery technology from increasing waste repositories, which will help both in hazard avoidance and as a potential source for industry. Phytoextraction, also known as phytomining, is a green and innovative method for recovering metals from waste, mainly focusing on resource supply, while contributing to hazard mitigation. In this context, plants have been found to be capable of phytomining platinum group metals (PGMs) to create stable metal nanoparticles that are useful in various industrial reactions. The use of mine tailings or waste mining waters for metal adsorption in plant beds is followed by controlled pyrolysis to produce stabilized PGM nanoparticles for het-erogeneous catalysts. The proposed solution to the global issue of metal depletion can lead to the creation of a new range of naturally derived catalysts. This review explores a multidisciplinary approach to evaluating metal sustainability, highlighting key aspects such as metal lifecycle analysis, waste sources, phytoextraction, and potential green chemical applications.

A pot experiment was conducted to study the effectiveness of remediation using a combination of Tween80 and alfalfa, as well as the enzyme responses involved in remediating polychlorinated biphenyls (PCBs)-contaminated soil. The results indicated that the degradation percentage of PCBs in contaminated soil was up to 53.8% after a 90 day culture in Tween80-enhanced phytoremediation, which was 25.2% more than that only by phytoremediation. The activities of urease, polyphenoloxide and hydrogen peroxide generally increased gradually with an increase in the planting time and Tween80 supplementation. This was attributed to the Tween80 stimulating the release of more root exudates into the PCBs-contaminated soil, improving the number and diversity of microbes and thereby enhancing enzymatic activity.

A pot experiment was conducted to study the absorption capacity of alfalfa under the enhancement of Tween80, and the physiological and biochemical responses of alfalfa to polychlorinated biphenyls (PCBs)-contaminated soil. It was found that the alfafa had a very limited PCBs absorption capacity., The absorption capacity of alfalfa root was larger than that of its shoot, and the addition of Tween80 can promote the absorption of PCBs. The alfalfa biomass and chlorophyll content was mainly inhibited by PCBs rather than Tween80. Alfalfa root activity was higher when treated with Tween80. The toxic effect of PCBs on the alfalfa root may be decreased by Tween80 solubilizing PCBs to decrease PCBs residue in contaminated soil. Soil organic matter content and micro-organism population may be increased by Tween80 providing an extra carbon source, thereby improving the absorption capacity and physiological and biochemical indicators of alfalfa. The experimental results provide some new possibilities in reducing risks associated with PCBs.