Phytoremediation Technology Research Articles

Evaluation of the effectiveness of the use of carbon fibres using salt of ethylenediaminetetraacetic acid for the purification of water bodies from heavy metals

As a result of various human activities, a large amount of heavy metals enters water bodies. Restoration of the environment with the help of plants is of great interest all over the world due to the possibilities offered by phytoremediation technology. This article is devoted to the development of an approach to wastewater treatment from heavy metals using Eichhornia using carbon fibre, which contributes to greater absorption capacity. It is proposed to use carbon fibre as “artificial roots” of plants. The article presents a scheme of an experimental setup with the use of carbon fibre in various combinations, including the use of a chelating agent - disodium salt of ethylenediaminetetraacetic acid (Trilon B) with various degrees of washing. It has been established that Eichhornia shows good results in the accumulation of heavy metals (Cu, Ni, Zn) in plant organs. The results indicate a positive effect from the use of carbon fibre as “artificial roots” in combination with Trilon B in relation to copper and zinc. The amount of remaining сopper and zinc in the water is the lowest at 4% and 8%. • Wastewater treatment from excess zinc, copper, and nickel. • Use of carbon fibres and chelating agent Trilon B for water treatment. • Sorption of copper, zinc, and nickel from wastewater using carbon fibres and Trilon B. • The efficiency of wastewater treatment from zinc and copper was more than 90%. • Carbon fibre and Trilon B can be used to improve wastewater treatment from heavy metals (Zn, Cu).

How Phytoremediator Plants Showing Potential of Maximum Remediation of Heavy Metals

Abstract: The original laboratory work done by Pragya Shah on Phytoremediation technology shows that Phytoremediator plants have maximum capacity of Phytoremediation technique.Heavy metal like lead Pb, cadmium Cd, Cr ie Chromium are dangerous for living beings, plants etc,if present in environment,soil, water makes a person ill.Mustard plant(Brassica juncea,nigra), Tomato plant (Solenum lycopersicon) are Phytoremediator plants showing maximum remediation of heavy metals.Mustard shows higher germination rates.Tomato(Solanum lycopersicon)BCF value is 1.43>1showing higher potential of Phytoremediation.Mustard plant(Brassica juncea) and Tomato plant ie Solanum lycopersicon showing higher rates of remediation of heavy metals ie 99.99% showing higher potential of Phytoremediation technique.

Biosorption of Boron from Industrial Wastewater by Green Algae Spirogyra sp.

Introduction: Increasing the concentration of Boron in drinking water, wastewater, and irrigation have negative effects on the human environment. This pollution can be partially removed by the application of phytoremediation technologies using algae or aquatic plants. The aim of the current study was to determine the biosorption capacity of the algae Spirogyra sp. for Boron from industrial wastewater and examine the best elimination conditions using different parameters.
 Materials and Methods: In this study, 100 g of fresh algal biomass was collected from the industrial wastewater of a copper mine located in Kerman, Iran.
 At first, algae was selected among various algal species concerning abundance and resistance ability to high concentrations of Boron. Then, removal of Boron by the algal was examined in terms of algae biomass levels (2 and 4 gr), incubation time intervals (2, 12. 24. 48, and 72 hours), and different concentrations of Boron (5, 10, 15, 25, and 100 ppm) on the were examined. The experiment was factorial with a completely randomized design framework and three replications.
 Results: The results presented that the elimination of Boron from industrial wastewater was performed by biomass of algae Spirogyra sp. The maximum Boron absorption was achieved at concentrations of 5 ppm and an incubation time of 12 hours. The absorption of Boron was higher in 4 gr than in 2 gr of algae biomass treatment.
 Conclusion: It can be concluded that algae Spirogyra sp. has a strong potential for boron removal in industrial wastewater containing boron ions.

Heavy metal pollution in the soil of contaminated sites in China: Research status and pollution assessment over the past two decades

Contaminated sites are receiving more and more attention internationally because they pose a serious threat to the ecological environment and human health. Although the research focused on heavy metals pollution in the soil of contaminated sites has been rapidly developing over the past two decades, systematic research status analysis and pollution assessment are still lacking. Here, through the “front page filtering” script and successive screening of the relevant studies, the research status of heavy metal pollution in the soil of contaminated sites worldwide and especially in China had been synthetically analyzed. The result showed that China and USA were the most active countries in related research, and the main research subjects were the assessment of contaminated sites and remediation methods. The keyword co-occurrence network of heavy metal contaminated sites in China was divided into three clusters, focusing on different environmental media, physical-chemical remediation and phytoremediation technologies. The types of contaminated sites in China mainly included mining areas (the largest proportion), industrial zones, sewage irrigation, and dismantling sites, etc. Cd and Pb were the most widely studied heavy metal in China. The pollution of heavy metals in the soils of contaminated sites was ranked as: Cd > Pb > Cu/Zn/Hg > As/Cr > Ni, and it was more serious in southeast China than northwestern China.

Comparison of Phytoremediation Potential of Nerium indicum with Inorganic Modifier Calcium Carbonate and Organic Modifier Mushroom Residue to Lead-Zinc Tailings.

At present, the application of phytoremediation technology in the ecological remediation of heavy metal tailings is receiving more and more attention. In this study, the physiological and biochemical response and tolerance mechanism of woody plant Nerium indicum to Pb and Zn under different proportions of inorganic modifier calcium carbonate (C1: 5%, C2: 10%, C3: 15%) and organic modifier mushroom residue (M1: 10%, M2: 20%, M3: 30%) was compared. The results showed that the pH value has a trend of C group > M group > CK group and organic matter has a trend of M group > CK group > C group. Phosphatase activity and catalase activity has a trend of M group > C group > CK group, but catalase was more vulnerable to the calcium carbonate concentration. Both modifiers can promote the transformation of Pb, Zn, Cu, and Cd in tailings to more stable organic bound and residual states. However, the stabilization effect of mushroom residue is better, and its stability is Pb, Zn > Cd, Cu. Both modifiers can increase the biomass of Nerium indicum and the modification effect of mushroom residue is better than calcium carbonate. Pb/Zn content and accumulation in Nerium indicum organs showed root > stem > leaf in all groups. Compared with the CK group, the enrichment coefficient of Pb/Zn in C1 and M1 groups decreased, while the translocation factor of Pb/Zn in C1 and M1 groups increased. With the increase in modifier concentration, the enrichment coefficient increases about 1.75~52.94%, but the translocation factor decreases rapidly (20.01~64.46%). Clearly, both the calcium carbonate and mushroom residue amendment could promote the growth ability of Nerium indicum in lead–zinc tailings and strengthen the phytoremediation potential.

Influence of DOM and its subfractions on the mobilization of heavy metals in rhizosphere soil solution

Long-term industrial pollution, wastewater irrigation, and fertilizer application are known factors that can contribute to the contamination of heavy metals (HMs) in agricultural soil. In addition, dissolved organic matter (DOM) plays key roles in the migration and fate of HMs in soil. This study investigated the effects of amending exogenous DOM extracted from chicken manure (DOMc), humus soil (DOMs), rice husk (DOMr), and its sub-fractions on the mobilization and bio-uptake of Cd, Zn, and Pb. The results suggested that the exogenous DOM facilitate the dissolution of HMs in rhizosphere soil, and the maximum solubility of Zn, Cd, and Pb were 1264.5, 121.3, and 215.7 μg L−1, respectively. Moreover, the proportion of Zn-DOM and Cd-DOM increased as the DOM concentration increased, and the highest proportions were 97.5% and 86.9%. However, the proportion of Pb-DOM was stable at > 99% in all treatments. In addition, the proportion of hydrophilic acid (Hy) and Pb/Cd in the rhizosphere soil solution were 17.5% and 8.3%, respectively. This finding suggested that the Hy-metals complex has a vital influence on the mobilization of metals, besides its complexation with fulvic acid and humic acid. Furthermore, the elevated DOM addition contributed to an increment of HMs uptake by Sedum alfredii, in the following order, DOMc > DOMs > DOMr. This study can provide valuable insights to enhance the development of phytoremediation technologies and farmland manipulation. Since the risk that exogenous DOM would increase the uptake of HMs by crops, it is also needed to evaluate this case from an agricultural management perspective.

Combined maize straw-biochar and oxalic acids induced a relay activity of abundant specific degraders for efficient phenanthrene degradation: Evidence based on the DNA-SIP technology

Biochar-oxalic acid composite application (BCOA) have shown to be efficient in the remediation of polycyclic aromatic hydrocarbon (PAH)-contaminated soil, but the functional degraders and the mechanism of improving biodegradation remains unclear. In this study, with the help of stable isotope probing technology of phenanthrene (Phe), we determined that BCOA significantly improved Phe mineralization by 2.1 times, which was ascribed to the increased numbers and abundances of functional degraders. The BCOA increased contents of dissolved organic carbon and available nutrients and decreased pH values in soil, thus promoting the activity, diversity and close cooperation of the functional Phe-degraders, and stimulating their functions associated with Phe degradation. In addition, there is a relay activity among more and diverse functional Phe-degraders in the soil with BCOA. Specifically, Pullulanibacillus persistently participated in Phe-degradation in the soil with BCOA throughout the incubation period. Moreover, Pullulanibacillus, Blastococcus, Alsobacter, Ramlibacter, and Mizugakiibacter were proved to be potential Phe-degraders in soil for the first time. The specific Phe degraders and their relay and cooperation activity in soils as impacted by BCOA were first identified with DNA-stable isotope probing technology. Our findings provided a novel perspective to understand the efficient degradation of PAH in the BCOA treatments, revealed the potential of soil native microbes in the efficient bioremediation of PAH-contaminated natural soil, and provided a basis for the development of in-situ phytoremediation technologies to remediate PAH pollution in future.

Effect of copper ions on the associations of Azospirillum bacteria with wheat seedlings (Triticum aestivum L.).

The physiological and biochemical activity of plant–microbial associations enables them to determine the mobility, bioavailability, and accumulation of heavy metals in plant tissues. These abilities are the basis for the use of plants and their associated microorganisms in the development of approaches that ensure both the prevention of the ingress of toxic metals into food crops and the extraction of pollutants from polluted soils by using phytoremediation technologies. Whether plant–microbial complexes are used successfully depends on the knowledge of how specific organisms interact with heavy metals. We evaluated the effect of copper ions on common wheat (Triticum aestivum L.) inoculated with three plant-growth-promoting rhizobacteria (PGPR) of the genus Azospirillum. We analyzed the growth variables of 14-day-old wheat seedlings, the content of photosynthesis pigments, the activity of plant oxidoreductases, and the accumulation of copper by plant tissues. All strains more or less compensated for copper toxicity to seedling development and increased metal accumulation in roots and shoots. Copper affected the photosynthetic apparatus of the inoculated plants, primarily by decreasing the content of chlorophyll b. An analysis of the activity of plant oxidoreductases (peroxidases and phenoloxidases), which are involved in the physiological responses of plants to pollutant stress, showed strain-specific dependence and a significant effect of copper on the inoculated plants. Overall, the obtained results clearly show that the effect of Azospirillum on the physiological and biochemical status of wheat is diverse. The compensatory effect of bacteria on copper toxicity and the simultaneous increase in metal accumulation in plant tissues can be considered as mutually exclusive crop-production aspects associated with the growing of food plants in heavy-metal-polluted areas.

Glutamine synthetase plays an important role in ammonium tolerance of Myriophyllum aquaticum

High-strength ammonium (NH4+), the main characteristic of swine wastewater, poses a significant threat to the rural ecological environment. As a novel phytoremediation technology, Myriophyllum aquaticum wetlands have high tolerance and removal rate of NH4+. Glutamine synthetase (GS), a pivotal enzyme in nitrogen (N) metabolism, is hypothesized to play an important role in the tolerance of M. aquaticum to high NH4+. Herein, the responses of M. aquaticum to GS inhibition by 0.1 mM methionine sulfoximine (MSX) under 15 mM NH4+ were investigated. After 5 days, visible NH4+ toxicity symptoms were observed in MSX-treated plants. Compared with the control, the NH4+ accumulation in the leaves increased by 20.99 times, while that of stems and roots increased by 3.27 times and 47.76 %, suggesting that GS inhibition had a greater impact on the leaves. GS inhibition decreased pigments in the leaves by 8.64 %–41.06 %, triggered oxidative stress, and affected ions concentrations in M. aquaticum. The concentrations of glutamine (Gln) and asparagine decreased by 63.46 %–97.43 % and 12.37 %–76.41 %, respectively, while the concentrations of most other amino acids increased after 5 days of MSX treatment, showing that GS inhibition reprogrammed the amino acids synthesis. A decrease in Gln explains the regulations of N-related genes, including increased expression of AMT in roots and decreased expression of GS, GOGAT, GDH, and AS, which would cause further NH4+ accumulation via promoting NH4+ uptake and decreasing NH4+ assimilation in M. aquaticum. This study revealed for the first time that GS inhibition under high NH4+ condition can lead to phytotoxicity in M. aquaticum due to NH4+ accumulation. The physiological and molecular responses of the leaves, stems, and roots confirmed the importance of GS in the high NH4+ tolerance of M. aquaticum. These findings provide new insights into NH4+ tolerance mechanisms in M. aquaticum and a theoretical foundation for the phytoremediation of high NH4+-loaded swine wastewater.

A Review on Potential of Field Crops in Phytoremediation

Heavy metals (HMs) are unique products, and as a result of their uniqueness, they cannot be converted into non-toxic forms. Both natural and man-made sources, such as mining, industry, and automobile emissions, release heavy metals into the environment. They enter subsurface waters through waterways or are carried away by runoff into surface waters, damaging both the water and the land at the same time. Because of population growth, industrialisation, and urbanisation, HM pollution is on the rise. Organic and inorganic pollutants are now poisoning a large area of the world, with heavy metal pollution becoming a serious problem in recent years. Toxic heavy metal has a detrimental influence on plant growth, which also damages DNA, and causes cancer in animals and humans. To remove, transport, stabilise, and breakdown contaminants from soil, sediment, and water, phytoremediation employs plants. Rhizofiltration, phytostabilization, phytovolatization, phytodegradation, and phytotransformation are some of its processes. Due to its advantages as a low-cost, effective, and environmentally friendly way of eliminating dangerous metals from the soil, phytoremediation has grown in favour in recent years. Field crops can create a thick green canopy on disturbed soil, improving the landscape and reducing contaminant movement through water, wind, and percolation. This increases the effectiveness of phytoremediation. More than 400 plant species, including the well-known Ricinus communis, Thlaspi, Brassica, and Arabidopsis, Helianthus annuus, Zea mays, and Brassica napus, have been identified as having potential for soil and water remediation. In this review article, we discuss the factors that contribute to heavy metal pollution, phytoremediation technology, the method by which heavy metals are taken up, and various studies that describe its practical use.

The research trend on arsenic pollution in freshwater: a bibliometric review.

We conducted a quantitative and qualitative bibliometric analysis based on 8740 research articles from the Web of Science Core Collection published in the last 20years (2000-2020) for a better understanding of the research progress and development trend of arsenic pollution in freshwater (FAP). The results showed a significant increase in the number of publications from 2007 to 2020, especially after 2015. Four of the top 10 productive authors are from China. Two of the top three research institutions are from China, and the publications of Chinese Academy of Sciences accounted for 5.40% of the total. China is also the center of the national cooperation network, indicating a greater influence of China in this scientific research field. The top three journals included Science of the Total Environmental, Environmental Science Technology, and Journal of Hazardous Materials. Besides arsenic, the high-frequency keywords in this field included adsorption, contamination, groundwater, removal, detection, and geochemistry. The researchers mainly focused on the groundwater environment, as well as the pollution hazards of arsenic in water bodies, remediation techniques, detection, migration, and transformation. Studies should pay more attention to the application and development of phytoremediation technology in the field of FAP in the future.

Seed Germination and Seedling Physiological Characteristics of Cardamine hupingshanensis K.M. Liu et al. (Brassicaceae) under Cadmium Stress

Cadmium is a naturally occurring element that can seriously harm food safety and human health with strong biological toxicity. Thus it is necessary to investigate the plants that can be used for phytoremediation of the metal. Therefore, the physiological mechanism of Cardamine hupingshanensis K.M. Liu et al. tolerance to cadmium for phytoremediation technology was conducted. The results showed that: [1] the germination potential, germination rate, germination index, and activity index of C. hupingshanensis increased at first and then decreased along with the increase of cadmium concentration; [2] with the increase of cadmium concentration, the root length, plant height, number of leaves, and weight per plant increased at first and then decreased, i.e. when the cadmium concentration is 1 mg/L, the chlorophyll content is slightly higher than the control, and when the cadmium concentration is greater than 1 mg/L, the chlorophyll content gradually decreases; [3] the relative conductivity and malondialhehyde of C. hupingshanensis increased gradually with the increase of cadmium concentration, and both were significantly higher than the control when the cadmium concentration was greater than 50 mg/L; the activities of superoxide dismutase, peroxidase, and catalase were stimulated; the glutathione peroxidase was significantly higher than the control at cadmium concentrations of 100 and 200 mg/L; [4] the absorption coefficient of C. hupingshanensis gradually decreases with the increase of cadmium concentration, whereas the transport coefficient is slightly affected by the increase of cadmium concentration. The average value of the ratio of cadmium concentration in the aboveground part to that in the underground part is 1.17. This shows that C. hupingshanensis is a plant with a super enrichment capacity for cadmium.

A novel phytoremediation technology for polluted cadmium soil: Salix integra treated with spermidine and activated carbon

A variety of plants have been used as phytoremediation materials to remove Cd from polluted soil. However, the disadvantages of using plants for decontamination include low biomass, low uptake, and inefficiency. We conducted experiments to determine the effects of spermidine and activated carbon treatments of Salix integra on Cd removal. The results showed that exogenous spermidine and activated carbon increased plant growth and root development compared with the CK. The increased dry mass (39.65–92.95%) with the combined spermidine and activated carbon treatments was higher than that with either single treatment (14.79–62.80%). The root length, surface area, root volume, and root diameter with the combined spermidine and activated carbon treatments (53.51–189.35%, 113.08–207.62%, 111.71–499.27%, and 32.51–106.62%, respectively) were higher than those of the lone application treatments (19.35–132.23%, 52.33–111.57%, 35.08–297.07%, and 24.22–81.38%, respectively). In addition, spermidine and activated carbon application reduced the toxicity of Cd to S. integra by improving the antioxidant capacity, thereby increasing the accumulation of Cd. The application of spermidine and activated carbon also changed the distribution of Cd in each part of S. integra. There was increased accumulation of Cd in the shoots and better absorption by the S. integra shoots, thereby improving their Cd remediation efficiency. The combined 0.8 mM spermidine and 0.5 g kg−1 activated carbon were most effective on removing Cd from the soil. The Cd removal efficiency was 78.11–120.86% higher than that of the CK. Our results may provide foundational information for understanding the mechanisms for the sustainable remediation of Cd-contaminated soil using a combination of spermidine and activated carbon.

Potential application of enhanced phytoremediation for heavy metals treatment in Nepal

Heavy metals contamination in soil and water resources is a great threat to developing countries because of the lack of waste treatment facilities. A majority of wastewater treatment methods are known to be expensive and out of reach for municipalities and small pollution treatment enterprises. Phytotechnology is a promising, sustainable, environment-friendly, and cost-effective technique for domestic and industrial wastewater treatment in places where land is available. However, interest in conventional remediation methods and the lack of information on recent advances in a significant portion of the society in developing countries have restrained the applications of phytoremediation. This review discusses the concept of phytoremediation, mechanisms of heavy metals removal by plants, and the potential application of enhanced phytoremediation technologies in developing countries like Nepal. The authors also review the commercially viable hyperaccumulator species with their native distribution, heavy metals intake capacity, and their availability in Nepal. Those native plants can be utilized locally or introduced strategically in other parts/countries as well. Thus, for a flora-rich country like Nepal, this study holds great potential and presents enhanced phytoremediation as an effective and sustainable strategy for the future.

Household greywater treatment using phytoremediation technology and CapsNet model

Household greywater treatment using phytoremediation technology and CapsNet model

Phytoremediation Technology and How to Increase Phytoremediation Capacity of Plants

Abstract: Phytoremediation technology is the use of green plants for remediation of heavy metals and contaminants. Heavy metals like lead (Pb), cadmium (Cd), Chromium (Cr) affect the green plants. The use of EDTA (Ethylenediaaminetetra acetic acid) increases the Phytoremediation capacity of plants. Increases the metal uptake of plants. It also increases the Phytoextracting capacity of plants. EDTA increases the growth of plants and helpful in maintaining green vegetation. EDTA is a stong chelator, it remediate the heavy metal from polluted soil by making complex with metal. Keywords: Phytoremediation, EDTA, Phytoextraction, Plants, Chromium.

Online Control of Lemna minor L. Phytoremediation: Using pH to Minimize the Nitrogen Outlet Concentration.

Phytoremediation technologies are employed worldwide to remove nutrient pollutants from agricultural and industrial wastewater. Unlike in algae-based nutrient removal, control methodologies for plant-based remediation have not been standardized. Control systems that guarantee consistently low outlet concentrations of nitrogen and phosphorous often use expensive analytical instruments and are therefore rarely viable. In this study, pH measurement was used as the sole input to control the nitrate outlet concentration in a continuously operated Lemna minor (lesser duckweed) phytoremediation tank. When grown in 20 L batches of modified Hoagland’s solution, it was found that a constant ratio exists between the amount of nitrate removed and the amount of acid dosed (required for pH control), which was equal to 1.25 mol N·(mol H+). The nitrate uptake rates were determined by standard spetrophotometric method. At critically low nitrate concentrations, this ratio reduced slightly to 1.08 mol N·(mol H+). Assuming a constant nitrogen content, the biomass growth rate could be predicted based on the acid dosing rate. A proportional-integral controller was used to maintain pH on 6.5 in a semi-continuously operated tank covered by L. minor. A nitrogen control strategy was developed which exploited this relationship between nitrate uptake and dosing and successfully removed upwards of 80% of the fed nitrogen from synthetic wastewater while a constant biomass layer was maintained. This study presents a clear illustration of how advanced chemical engineering control principles can be applied in phytoremediation processes.

Potential use of bamboo in the phytoremediation in of heavy metals: A review

There are many literature sources focusing on the phytoremediation of woody plants, but there are only few dealing with the phytoremediation of bamboo plants. Phytoremediation technology has the advantages of little disturbance to the environment and low remediation cost. Bamboo mainly exists in tropical and subtropical regions. As an energy plant, bamboo has a fast growth cycle, large biomass, simple cultivation, high economic efficiency, and convenient harvesting, which highlights the advantages of bamboo in phytoremediation. In addition, bamboo plants have good tolerance and uptake ability to heavy metals and have high application potential and development value in uptaking heavy metal contaminated soil. However, due to climate, temperature and other reasons, bamboo cannot be widely planted in most countries. Research status of remediation of heavy metal contaminated soil by bamboo plants is summarized. The feasibility of its application in heavy metal contaminated soil is discussed in this paper. Aiming at the shortcomings of existing research, bamboo plants have a prospect in the field of plant phytoremediation for the future.

Pennisetum purpureum Improved Polycyclic Aromatic Hydrocarbons Removal in Weathered-Petroleum Contaminated Soil

Petroleum hydrocarbons are among the major driving forces of advancement in the last Century. Some of the hydrocarbons especially polycyclic aromatics are however of health and environmental significance, due to their recalcitrance and persistence leading to adverse effects on health and ecosystem stability. A number of treatment technologies have been used to cleanup hydrocarbon contaminants and the use of phytoremediation technology have recently been described as promising. In this study, phytoremediation of weathered crude oil contaminated soil was carried out in a microcosm using Pennisetumpurpureum for 60 days. Pristine soil samples were collected and mixed with weathered petroleum contaminated soil to achieve 5%, 25%, 35% and 50% w/w contamination levels. Bacterial species in the rhizosphere were isolated and identified and residual oil was extracted and analyzed using GC-MS. Results showed that there was high bacterial population in rhizosphere (5.0×105 cfu/g to 6.4×105 cfu/g) than non-rhizosphere soil (2.4 ×105 cfu/g to 4.0×105 cfu/g); and Bacillus spp. (64.71%) were observed to be predominant in the rhizosphere followed by Micrococcus spp. (17.65%), Pseudomonas aeruginosa (5.88%), Klebsiella pneumoniae (5.88%) and Flavobacterium sp. (5.88%). Hydrocarbon concentration in the rhizosphere was reduced by 82.5%, 60.5%, 58.0% and 48.8% respectively. Complex polycyclic aromatic hydrocarbon compounds detected in the control using GC-MS were significantly reduced or completely degraded. Polycyclic aromatic hydrocarbons such as anthracene, naphthalene, fluorene, benzo (a) anthracene, pyrene and chrysene were significantly reduced at a rate ranging between 13.33% and 97.54%. Based on the rate of PAHs reduction observed in this study, it was evident that P. purpureumsupports cleanup of persistent hydrocarbon contaminants in soil environment. The use of this plant in large scale petroleum hydrocarbon cleanup under field conditions should be investigated.

Токсичні властивості свинцю, його вплив на харчові ланцюги і методи ремедиації (огляд літератури)

The purpose of the study was to review the most recent findings related to lead toxicity for plants, animals and humans. It is stated that the highest potential belongs to biological techniques and the most up-to-date lead phytoremediation technologies. Results and discussion. Lead is one of the most toxic heavy metals which frequently occurs in the environment. Various quantitative indices are used to assess lead toxicity at trophic levels of a food chain, including the levels of lead absorption by plants. Hyperaccumulating plants can accumulate more than 1000 mg/kg of the metal. Higher lead concentrations are connected with fruit plants. Lead transport in animals is done through the blood circulatory system, whereby bones are the main lead absorbers (~ 90%), where lead replace calcium and reduces the bone mineral density. Lead poisoning in humans most frequently results from peroral intake and absorption through the gastrointestinal tract. The main process of lead transport from the gastrointestinal tract to various body tissues is conducted via erythrocytes, where lead binds to hemoglobin. The half-life of lead in blood and soft tissues has been estimated as 35 and 40 days, respectively. Lead may stay in the bones up to 30 years; its concentration rate in the teeth and bones increases with age. Over 95% of lead deposit in the skeleton represent an insoluble phosphate. The biological half-life of lead in children is significantly larger than in adults. The total lead load on skeleton makes 80-95% in adults and around 73% in children. Lead toxicity primarily targets the human central nervous system, and child exposure to high amounts of lead from the environment, particularly in the case of anemia, entails low intelligence and movement disorders. Mothers can transmit lead to fetus or infants during breast-feeding. There are various processes that seek to reduce the overall lead concentration and accumulation in the food chain. Out of those, the most effective are biological techniques of lead remediation from contaminated resources. They include phytoremediation and microbiological treatment. The first option reduces lead mobility in the root zone of plants through complex formation. The second option reduces lead availability in the environment via employing local microorganisms. Both options are a natural, safe, efficient, and environmentally friendly technology which implies cost-effective operation and represents no threat to the environment and health. However, a high potential is detected in biotechnological and genetic approaches, such as genomics, metagenomics, metabolomics, proteomics, transcriptomics, nanoparticles, and isotope probing. These are the most up-to-date technologies for lead phytoremediation. The use of omics approaches implies identifying candidate genes for an efficient lead removal, diverse phylogenetic research into the sequence of genes and proteins that control lead bioremediation and genetically modified plants cultivation via transgenesis, which are able to restore various wastewaters, contaminated lands, and can be beneficial for practical application in bioremediation. Conclusion. The most recent research and development in the field of nanosciences provide access to even more efficient and stable approaches to remediation that are being successfully applied in cleaning soils, deposits, solid waste, and wastewaters