Biological Accumulation Coefficient Research Articles

Valorization of rare earth processing byproducts for agriculture usage

Sandy texture soil, a major problem for agriculture requires structure and capacity improvements. However, utilization of soil conditioner may arrest this problem. This research was carried out to investigate the accumulated levels of metal ions and radionuclides in water, soil and plants following phosphogypsum organic (PG organic) added to a sandy soil for 23-month in 3 cropping seasons. The condition in the field was simulated in the laboratory using an open leaching column for 30-day under constant but different pH of leachant. More ions were released at pH < 4.6 and decreases greatly at pH > 5.6. The metal ions measured in the surface and borehole water, and soils were below the target values for respective standard raw drinking water. The metal ions did not accumulate in soil, plant and grain, and water as indicated by biological accumulation coefficients, contamination factors, I-geo index and pollution load index in a sandy soil that received the PG organic. Naturally occurring radionuclide concentrations, such as 226Ra, 228Ra, and 40K, in soil and plant tissue were found to be lower than the average value reported by several earlier studies. Under field condition the pH of water (i.e., rainfall) was greater than pH 5.6, thus renders PG organic became less soluble. There was no leaching of natural occurring radionuclides to the groundwater. Therefore, the application of PG organic to the studied soil had no impact on the soil, plants, and water and suitable as a soil conditioner in sandy texture soils.

ЦИНК В СИСТЕМЕ «ПОЧВА-РАСТЕНИЕ» ПРИ ДЛИТЕЛЬНОМ ПРИМЕНЕНИИ МИНЕРАЛЬНЫХ УДОБРЕНИЙ В УСЛОВИЯХ ЮЖНОЙ ЛЕСОСТЕПИ ОМСКОЙ ОБЛАСТИ

A long-term stationary experiment was carried out on meadow-black soil in the southern forest-steppe of the Omsk region of Western Siberia, it was found that systematic application of mineral fertilizers (during six rotations of a five-field grain-fallow crop rotation) did not lead to accumulation of zinc above the APC in accordance with the Hygienic Standards GN 2.1.7.2511- 09. It has been proven that the amount of total zinc (5M HNO3 extraction) over the years of the research decreased in comparison with the initial value by 15% in a natural background and by 25% in a fertilized background due to its greater removal by plants and migration down the soil profile. Systematic application of mineral fertilizers on average over three years (2017-2019) increased the annual zinc removal by wheat plants by 16%. The content of zinc mobile form in the soil (AAB extraction, pH = 4.8) is estimated as average (2.1-2.2 mg / kg). The dependence of zinc mobile forms on acid-soluble forms was revealed, which is described by the equation y = 0.072x-0.643. The zinc content in spring wheat plants, depending on the fertilization, varied from 5.8 to 7.6 in straw and from 30.8 to 34.3 mg / kg in grain. The biological absorption coefficient was 13.1-12.8; the coefficient of biological accumulation was 14.9 -15.9, which indicates that zinc is intensively involved in the biochemical cycle of the agrocenosis during spring wheat cultivation, and its deficiency becomes a factor which limits the crop yield.

Ex situ phytoremediation trial of Sardinian mine waste using a pioneer plant species

The mitigation of metals contamination is currently a crucial issue for the reclamation of mine sites. Indeed, mine wastes are often disposed in open dumps and consequently pollutants are subjected to dispersion in the surrounding areas. In this study, the potential use of Helichrysum microphyllum subsp. tyrrhenicum for phytostabilization was evaluated in ex situ conditions. Ninety specimens were randomly selected and were planted in three substrates (reference substrate, mine waste materials, and mine wastes with compost). Mineralogical compositions of substrates, rhizosphere, and roots were assessed through X-ray diffraction (XRD). Zn, Pb, and Cd concentrations of substrates, rhizosphere, soil pore waters, and plant tissues were determined. The phytostabilization potential was determined through the application of biological accumulation coefficient (BAC), biological concentration factor (BCF), and translocation factor (TF). Moreover, survival and biometric parameters were assessed on plant specimens. The polluted substrates and related rhizosphere materials were mainly composed of dolomite, quartz, pyrite, and phyllosilicate. Zn was the most abundant metal in substrates, rhizosphere, and soil pore waters. XRD analysis on roots showed the presence of amorphous cellulose and quartz and Zn was the most abundant metal in plant tissues. H. microphyllum subsp. tyrrhenicum restricts the accumulation of the metals into roots limiting their translocation in aereal parts, indicating its potential use as phytostabilizer (BCF, BAC, TF < 1). Survival and growth data showed a great adaptability to different substrates, with an evident positive effect of the implementation of compost which increased the plant survival and decreased the metals uptake into roots.

Determination of the Elemental Composition of Aromatic Plants Cultivated Industrially in the Republic of Moldova Using Neutron Activation Analysis

The mineral contents of roots, leaves, stalks, and inflorescences of the aromatic plant species Anethum graveolens L., Coriandrum sativum L., Lavandula angustifolia Mill., Levisticum officinale W.D.J. Koch, and Salvia sclarea L. were studied by means of neutron activation analysis. The contents of 36 major and trace elements were determined and biological transfer coefficients were calculated. Among major and minor elements, K with a content in the range of 9230–59,600 mg/kg and Fe in the range of 69–3420 mg/kg were the most abundant elements in the studied plants. The content of the toxicant As ranged between 0.14–0.79 mg/kg; however, in the leaves (1.3 mg/kg) and inflorescences (1.0 mg/kg) of L. angustifolia there was found to be about 1 mg/kg, equal to the guideline maximal level recommended for food by the WHO. By comparing the data to Markert’s Reference Plant, “chemical fingerprints” were identified for each species. High contents of the elements Al, Hf, Se, Sc, Na, Ta, Th were determined in all studied plants. Collocated soil samples from the cultivation field were analyzed to calculate the biological accumulation coefficients for 35 of the elements determined in the plants. Considering the levels of chemical elements, the medicinal herb samples investigated are considered as relatively safe for human consumption.

Biochemical transmutation in Lumbricus terrestris and phytoextraction of heavy metals from the swamp of Challawa industrial layout, Kano, Nigeria

Discharge of untreated industrial effluents has been associated with soil contamination. Biochemical alterations in Lumbricus terrestris and remediation capacity of Azadirachta indica tree from industrial effluent discharge locations in Challawa (A and B) and Kura village (control location C) were assessed. Levels of nitrate, phosphate, iron, chloride, and hardness at locations A and B were significantly (p < 0.05) higher than those at location C, but their sulfate concentrations were significantly (p < 0.05) weaker. pH and magnesium concentration at location A were significantly higher than those at locations B and C. Levels of Fe, Cu, Zn, Pb and Mn in soils at the discharge locations were significantly (p < 0.05) higher than those of C. Azadirachta indica tree (AIT) had a translocation factor (TF) > 1 for Pb and Zn, while its biological concentration factor (BCF) was > 1 for Fe. Values of biological accumulation coefficient (BAC) for AIT and soil contamination factor (CF) were < 1 for the metals. Bioindicators of oxidative stress (MDA, GST, CAT and SOD) in earthworm supernatants from the discharge locations were significantly higher (p < 0.05) compared to that at location C, while their GSH levels were significantly (p < 0.05) lower. Acetylcholinesterase (AChE) activity in earthworm supernatants from discharge locations was significantly lower (p < 0.05) in comparison with the control. Trends in results revealed that AIT may be useful for extraction and stabilization of heavy metals in polluted soils. Also, the biochemical alterations in L. terrestris may serve as sensitive bioindicators of soil contamination.

Cadmium and zinc migration in Scots pine stands growing in contaminated areas from metallurgical plant emissions

The accumulation of cadmium and zinc in aboveground and belowground organs of Scots pine (Pinus sylvestris L.) and the metal migration extents in the soil–plant system were analysed for the stands growing in contaminated areas from metallurgical plant emissions. The pine stands of the comparable age (38–45 years old), and a similar structure, selected for research, is grown in the sanitary protection zone of the city of Lipetsk (Lipetsk Region, Russia) in the vicinity of the metallurgical combine (Novolipetsk Steel). Using atomic absorption spectrometry determined cadmium and zinc content in the soil, fine (< 1 mm) roots, annual shoots, and needles. In the impact zone, the Novolipetsk Steel releases significant contamination of the soil’s surface layers with cadmium and zinc. The present investigation identifies the changes in cadmium and zinc content in the soil that correlated (moderately and strongly) with acidity and humus in the ground. The pine fine roots in the impact zone take in these metals sufficiently, with zinc being absorbed more intensively than cadmium. As against the fine roots, it has been indicated that one-year needles and shoots actively cumulate zinc. The biological accumulation and migration coefficient values show that zinc is actively stored in Scots pine annual needles and shoots.

Phytoremediation as a method for cleaning sludge beds of biological treatment plants from heavy metals

The aim of this study is to select a phytoremediation plant for cleaning sludge beds of biological treatment plants from heavy metals. The study was conducted on sludge beds of biological treatment facilities of Veliky Novgorod with a sludge retention time of 1 year and 15 years. It is established that the forms of metals in the sludges and wastewater sludge depend on the nature of the metal. Manganese (II) predominantly binds to compounds that make up sludge and wastewater sludge by the ion exchange mechanism, copper (II) – by the complex formation mechanism, zinc (II) – is codeposited with calcium and magnesium carbonates, manganese (IV) and iron hydroxides (III). Six selected plants were analyzed (bedstraw, cow vetch, field daisy, silverweed cinquefoil, base vervain, winter cress), those growing on sludge beds with a sludge retention time of 15 years, for the content of copper (II), zinc (II) and manganese (II) in different parts of plants. The phytoremediation plant was selected according to the indicators of the coefficient of biological accumulation (coefficient of biological accumulation) and translocation factor. It has been established that the bedstraw can be called a universal phytoremediation plant, in the absence of significant sludge contamination with copper (II), it is most preferable to use base vervain. Selected phytoremediation plants can be used for artificial planting on sludge beds in order to further use these beds as fertile lands.

Screening of Native Plants Growing on a Pb/Zn Mining Area in Eastern Morocco: Perspectives for Phytoremediation.

Screening of native plant species from mining sites can lead to identify suitable plants for phytoremediation approaches. In this study, we assayed heavy metals tolerance and accumulation in native and dominant plants growing on abandoned Pb/Zn mining site in eastern Morocco. Soil samples and native plants were collected and analyzed for As, Cd, Cu, Ni, Sb, Pb, and Zn concentrations. Bioconcentration factor (BCF), translocation factor (TF), and biological accumulation coefficient (BAC) were determined for each element. Our results showed that soils present low organic matter content combined with high levels of heavy metals especially Pb and Zn due to past extraction activities. Native and dominant plants sampled in these areas were classified into 14 species and eight families. Principal components analysis separated Artemisia herba-alba with high concentrations of As, Cd, Cu, Ni, and Pb in shoots from other species. Four plant species, namely, Reseda alba, Cistus libanotis, Stipa tenacissima, and Artemisia herba-alba showed strong capacity to tolerate and hyperaccumulate heavy metals, especially Pb, in their tissues. According to BCF, TF, and BAC, these plant species could be used as effective plants for Pb phytoextraction. Stipa tenacissima and Artemisia herba-alba are better suited for phytostabilization of Cd/Cu and Cu/Zn, respectively. Our study shows that several spontaneous and native plants growing on Pb/Zn contaminated sites have a good potential for developing heavy metals phytoremediation strategies.

Contamination assessment, health risk evaluation, and source identification of heavy metals in the soil-rice system of typical agricultural regions on the southeast coast of China.

To quantitatively assess heavy metal accumulation and potential ecological and human health risks as well as analyze the sources of metals in a typical soil-rice system located on the southeast coast of China, 120 topsoil samples and corresponding rice grain samples were collected across the study area. The concentrations of As, Cd, Pb, Cr, Hg, Zn, Cu, and Ni were analyzed. The results revealed that Hg, Cd, and Cu were the main pollutants in soils. Besides, according to geo-accumulation value of Hg, 18.3% of samples were at or above moderate contamination levels. Additionally, the soil was in moderate ecological risk from combined heavy metal pollution, and 49.7% and 27.0% of this risk could be attributed to Hg and Cd pollution, respectively, due to their high toxic-response factors. For the rice samples, Cd content showed the highest biological accumulation coefficient value (40.8%) in rice grains and was slightly greater than its maximum allowable value (MAV) (0.2mg/kg) in 7.5% of samples, whereas the other metals were all lower than their corresponding MAVs. Heavy metal exposure (especially As exposure) via rice consumption causes significant carcinogenic and non-carcinogenic risks to adults, and non-carcinogenic risk to children, while the carcinogenic risk to children was at tolerable level. Greater rice consumption might be responsible for the greater health risk to adults than children. Natural sources (loaded heavily with Cr and Ni) such as lithogenic components and soil parent materials, agricultural activities (loaded heavily with Cd, Cu, and Zn), especially excessive use of pesticides and fertilizers, and industrial activities (loaded heavily with Hg, Pb, and As) including vehicle emissions, coal combustion, and those of the textile and chemical industries were identified as the main sources. Effective regulations should be enforced to guarantee the safety of farm produce and protect ecological and human health in the study area.

Ecological-health risk assessment and bioavailability of potentially toxic elements (PTEs) in soil and plant around a copper smelter.

Soil and the dominant plant species in the vicinity of Khatoon Abad copper smelter in Kerman province of Iran are examined to determine contamination, bioavailability, and ecological-health risk of potentially toxic elements (PTEs) based on 23 collected soil samples and 13 Artemisia siebri plant species. Cu, Mo, As, and Sb display a significant level of enrichment in soil. Ecological risk assessment shows that Cu, As, and Cd pose the highest ecological risk. The results of PTEs fractionation reveal that, on average, Cu, As, Cd, Pb, Zn, and Mo are mostly distributed between non-residual fractions reflecting higher mobility and potential ecological risk, while Cr, Ni, and Co are significantly distributed within the residual fraction, and do not pose a serious ecological risk. Mobility factor suggests high bioavailability of Cu for plants followed by As, Cd, Pb, Mo, Co, Ni, and Cr. Biological accumulation coefficient displays higher phytoavailability of Mo and Cd. PTEs transfer within plant follows the order of Mo > As > Pb > Zn > Cu > Ni > Co > Cr > Cd. The results of phytoavailability indicate the high tendency of Cd to bioaccumulate in Artemisia's root, while Mo, As, and Pb tend to translocate towards Artemisia's shoot. Calculated hazard index and incremental lifetime cancer risk revealed that As poses the highest non-carcinogenic health risk, and As and Pb pose the greatest carcinogenic health risk in both adults and children.

The Heavy Metals in the System "Soil as a Wild-growing Medicinal Plant" on the Example of Tanacetum Vulgare L

The features of the accumulation of heavy metals in medicinal plant raw materials Tanacetum vulgare L. in the conditions of the Trans-Urals region of the Republic of Bashkortostan are discussed. The variation-statistical indices of the content of heavy metals in soils and in plants are calculated. Soils and plants have high coefficients of heavy metals variation, with the exception of manganese in the soil, which is characterized by moderate variability. An increased level of heavy metals mobile forms, such as Cu, Zn, Mn, Fe, Pb, Cd, has been detected in all soil samples. All selected samples had an elevated level of mobile forms. According to the degree of contamination, the studied soils were classified as permissible. In tansy plants, the concentration of trace elements-biophiles exceeded the norm in Fe 1.7–6.24, in Cd 1.3–1.7 times, and the concentrations of Cu, Zn, Mn, Pb in the aboveground and underground parts of the species remained within the normal range. It is revealed that the root system of Tanacetum vulgare L. contains higher values of the studied elements than the aerial parts. According to the intensity of absorption, the elements are arranged in the following sequence: Zn → Cd → Cu → Fe → Mn → Pb. According to the coefficient of biological accumulation in tansy, ordinary zinc and iron belong to the elements of weak accumulation, copper, manganese, lead, cadmium –to the elements of weak capture.

Biochar effect on crop performance and Pb and Zn uptake of tomato (Solanum lycopersicum, L.) plants grown on heavy metals contaminated Kosovo soils

A greenhouse pot experiment was conducted to evaluate the effect of biochar on the growth and uptake of Pb and Zn by tomato plants (Solanum lycopersicum, L.) cultivated in two highly contaminated Kosovo soils, A and B. Plants were cultivated in the biochar amended and unamended soils. As expected, the biochar addition to the two polluted soils has contributed to significantly improve the crop yields, in terms of both fresh and dry weight. Further, results indicated that the effect of biochar on metal mobility is closely related, besides its properties, to soil’s native characteristics. In fact, the addition of biochar to soil B had also beneficial effects on the uptake of both metals, halving in some cases the values of the biological accumulation and transfer coefficients, while it did not show the same efficacy on soil A.

Iron and manganese migration in \u201csoil\u2013plant\u201d system in Scots pine stands in conditions of contamination by the steel plant\u2019s emissions

In this paper, Scots pine (Pinus sylvestris L.) roots grown in soils with and without contamination from emission of a plant steel were analyzed for Fe and Mn, as well as the shoots and needles with and lacking pollution. The aim was to assess the content of Fe and Mn in soils under given conditions, and the interaction between pine plant and soil in terms of metal accumulation in the fine roots, annual shoots, and annual needles. The iron content in the soil of polluted areas does not contrast with its control amount. Conversely, the iron content in fine pine roots under contamination conditions is 2.1–4.4 times higher than the control values. There were no significant excesses of the manganese content in the soil in polluted conditions compared to the control, but its content in the 0–20 cm soil layer is 27–32 times higher than the background concentrations. The iron contentment in belowground (fine roots) and aboveground (annual shoots and needles) parts of pine trees in a context of contamination is higher than the control values (2.1–4.4 and 1.50–1.54 times, respectively). The manganese content in fine pine roots under contamination conditions is 2.8–10.7 times less than in control, while its content in shoots and needles is higher (2.23–2.76 times) in comparison with the control. Based on the values of the biological accumulation and migration coefficients, what in each case slighter than one, for Scots pine the iron represent not an element that actively accumulates. Nevertheless, for manganese, this stock model is valid only for fine roots, whereas under the contaminated environment, the metal mobility steepen, and the migration pattern shifts towards increased manganese accumulation in the aboveground part of pine trees.

Arsenic in the rock-soil-plant system and related health risk in a magmatic-metamorphic belt, West of Iran.

Following earlier reports of water contamination and arsenic (As) toxicity symptoms in residents of Kurdistan Province, As was determined in rock, soil and plant samples to investigate its fate from rock to crops and its potential effects on human health. Total As content ranged from 4.9 to 10,000mg/kg, 7.7-430mg/kg and < 0.05-25,079µg/kg (dry weight) in rock, soil and plant samples, respectively. The Qorveh-Bijar region data indicated that magmatic differentiation has enriched late magmatic fluids in As. High rare earth elements concentration, dissociation coefficient, and positive Eu anomaly in volcanic rocks, indicated the prevalence of intermediate to felsic composition. The highest As concentration was measured in travertine. In soil, As average level in Qorveh and Bijar was 48.5 and 107mg/kg, respectively. Higher pollution index and geoaccumulation index (Igeo) were also calculated for Bijar County. The As concentration in crop samples was greater than the recommended maximum permissible concentration for foodstuff. Mann-Whitney U test revealed significant differences between As concentration in different plant species and no difference between plants in Bijar and Qorveh. Also, alfalfa displayed the highest biological accumulation coefficient among the investigated plants. The calculated chronic daily intake of As in Bijar County was higher than the recommended levels for wheat and barley grains. Moreover, the hazard quotient (HQ) and incremental lifetime cancer risk assessments revealed high non-cancer (HQ > 1 for both adults and children) and cancer (particularly for barley in Bijar) risks for inhabitants via consumption of As contaminated crops cultivated in the study area.

Soil nutrients and heavy metal availability under long-term combined application of swine manure and synthetic fertilizers in acidic paddy soil

Fertilization is a vital approach to increase the crop yield by enhancing soil fertility, but some of the fertilizer sources such as pig manure contain non-essential toxic heavy metals, which can produce the environmental and public health risk. Therefore, the purpose of this study was to investigate the soil fertility and heavy metal pollution risk under long-term fertilization in acidic paddy soil. Fertilizer treatments that were arranged in randomized complete block design (RCBD) included CK (no fertilization), NK (inorganic nitrogen and potassium fertilization), NPK (inorganic NK and phosphorus fertilization), NPKM1 (70% of NPK and 30% pig manure application), NPKM2 (50% of NPK and 50% of pig manure application), and NPKM3 (30% of NPK and 70% of pig manure application). The rice grain yield and soil nutrient contents were highest under NPKM3 treatment. Long-term addition of manure significantly (P ≤ 0.05) increased soil pH and SOC content compared to the NPK fertilization. Soil available and total Cr, Cd, and Hg contents were highest under NPKM3 treatments, while soil total and available Pb content was significantly (P ≤ 0.05) higher under NPK treatment. Highest ecological risk (IR) was (1904) under NPK treatment and highest pollution load index (PLI) was 1.5 under NPKM3 treatment. Cd concentration in rice grain exceeded the maximum permissible limit of 0.1 mg kg−1 under combined application of manure and inorganic fertilization treatments. Grain Cr, Hg, and Pb contents were within safe limits of their concentration in all treatments. Moreover, biological accumulation coefficients of Cr, Cd, Hg, Pb, Zn, and Cu were highest under NPK treatment. Redundancy analysis (RDA) showed that soil pH and nutrient contents showed significant correlation with heavy metal concentrations in soil. Soil pH showed significant (P ≤ 0.05) positive effect on Cd accumulation in rice grain. Heavy metals in pig manure should be monitored before application to the field to reduce the risk of heavy metal pollution in soil and plant. Furthermore, combined application at the rate of 70% inorganic fertilization and 30% of manure could be better strategy to produce high crop yield with minimum risk of heavy metal contamination in soil and food crops.

Evaluation of Vetiver Grass Uptake Efficiency in Single and Mixed Heavy Metal Contaminated Soil

Most phyto-remediation studies have been conducted merely on a single type of contaminant element without consideration of the influence of other co-existent contaminants. In this study, Vetiveria zizanioides (Linn.) Nash was evaluated in both single and mixed heavy metal (Cd, Pb, Cu and Zn) spiked contaminated soil. The plant growth, metal accumulation and overall efficiency of metal uptake by different plant parts (lower root, upper root, lower tiller and upper tiller) were investigated in detail. The relative growth performance, metal tolerance and phyto-assessment of heavy metal in roots and tillers of Vetiver grass were assessed. Metals in plants were measured using the flame atomic absorption spectrometry (F-AAS) after acid digestion. The root-tiller (R/T) ratio, tolerance index (TI), translocation factor (TF), biological concentration factor (BCF), biological accumulation coefficient (BAC) and metal uptake efficacy were estimated to examine the ability of metal accumulation and translocation in Vetiver grass. No significant difference (p > 0.05) of plant height was observed among all single and mixed heavy metal spiked soils compared with the control. However, significantly higher (p > Cu > Pb > Cd. Moreover, lower roots and lower tillers of Vetiver grass revealed a strong tendency for greater uptake and accumulation of all four heavy metals in both single and/or mixed spiked contaminated soils.

Ecological Risk Assessment, Interpolation, and Pollution Source Identification of Toxic Elements in Soils and Leaves of the Vineyard of Malayer County

Grape is a strategic product in the county of Malayer. Despite the great importance and existence of polluted resources in the vicinity of vineyards in Malayer, there are few studies conducted in this regard. To evaluate the pollution level of toxic elements in these vineyards, 20 sampling stations were selected randomly and samples of garden soil and leaves of grapevine species were collected. After the acidic digestion of the samples, the concentrations of the heavy metals were measured using atomic absorption spectrometer. Then, the indices of contamination factor (Cf), geoaccumulation index (Igeo), biological accumulation coefficient (BAC), and ecological risk index (RI) were calculated. According to the results obtained for Igeo and Cf indices, the soil in the study region was moderately contaminated with copper. However, the ecological risk index and BAC of the studied region were low. To investigate the spatial distribution of copper in the studied region, the spatial distribution map was prepared. To locate the source of copper contamination and investigate the effect of various land uses on the amount of contamination, land use map (LUM) of vineyards was generated. To this end, images were downloaded from Landsat Satellite, and after the exertion of various corrections on the images based on the supervised classification method, the LUM with agricultural, residential, vineyard, brick furnace and pasture classes was prepared. The comparison of the LUM and the copper contamination map illustrated that the copper contamination was higher in the places with urban and adobe furnace land-use types.

Evaluation of chromium phytoremediation potential of some plant species of Dir Lower, Khyber Pakhtunkhwa, Pakistan

Chromium is the second most common metal pollutant in the soil, sediments and groundwater, due to its extensive industrial application, hence posing a serious environmental concern. Various remediation approaches including phytoremediation have been proposed to remediate chromium polluted waters and soils. In the present research, a total of sixty-one plant species belongs to thirty families were analyzed for the concentration of Chromium. Chromium was analyzed in the soil of the root zone, root and shoot of each plant. The concentration of chromium in the soil of different sites and plant parts (roots and shoots) was found in mg/kg in the range of 0.33–48.73, 8–1233.3 and 10.23–568.33 respectively. The highest concentration of chromium was found in the soil of site Site 41 (48.73 mg/kg) followed by Site 18 (47.83 mg/kg) and Site 6 (45.33 mg/kg). Among the analyzed plants, the highest concentration of chromium in mg/kg was found in the root of Cannabis sativa (1233.3) while its highest concentration was found in the shoot of Allium griffithianum (568.33). Phytoremediation potential of the analyzed plants was evaluated by the calculation of Bioconcentration Factor (BCF), Translocation Factor (TF) and Biological Accumulation Coefficient (BAC). Thirty-eight plant species showed feasibility for the phytostabilization of chromium (Cr_Excluders) based on BCF value and the concentration of chromium in the root. Plants i.e. Argyrolobium stenophyllum, Silybum marianum, Bryophyllum daigremontianum, Limonium macrorhabdon, Calendula arvensis and Delphinium suave were found the most efficient plant for the phytostabilization of chromium. Fifteen plant species showed feasibility for the phytoextraction of chromium (Cr_Indicators) based on TF value. The most efficient plant's species among them for the phytoextraction of chromium are Rosularia adenotricha, Catharanthus roseus, Allium griffithianum, Himalaiella heteromalla, Stellaria media, Salvia moorcroftiana and Marrubium vulgare. Based on BCFs, TFs and BACs value and the concentration of chromium in plant shoot six plant species Allium griffithianum, Catharanthus roseus, Himalaiella heteromalla, Geranium rotundifolium, Marrubium vulgare and Solanum nigrum were found chromium hyperaccumulators.

Phytoassessment of Vetiver grass enhanced with EDTA soil amendment grown in single and mixed heavy metal-contaminted soil.

Over the years, ethylene-diamine-tetra-acetate (EDTA) has been widely used for many purposes. However, there are inadequate phytoassessment studies conducted using EDTA in Vetiver grass. Hence, this study evaluates the phytoassessment (growth performance, accumulation trends, and proficiency of metal uptake) of Vetiver grass, Vetiveria zizanioides (Linn.) Nash in both single and mixed heavy metal (Cd, Pb, Cu, and Zn)-disodium EDTA-enhanced contaminated soil. The plant growth, metal accumulation, and overall efficiency of metal uptake by different plant parts (lower root, upper root, lower tiller, and upper tiller) were thoroughly examined. The relative growth performance, metal tolerance, and phytoassessment of heavy metal in roots and tillers of Vetiver grass were examined. Metals in plants were measured using the flame atomic absorption spectrometry (F-AAS) after acid digestion. The root-tiller (R/T) ratio, biological concentration factor (BCF), biological accumulation coefficient (BAC), tolerance index (TI), translocation factor (TF), and metal uptake efficacy were used to estimate the potential of metal accumulation and translocation in Vetiver grass. All accumulation of heavy metals were significantly higher (p < 0.05) in both lower and upper roots and tillers of Vetiver grass for Cd + Pb + Cu + Zn + EDTA treatments as compared with the control. The single Zn + EDTA treatment accumulated the highest overall total amount of Zn (8068 ± 407 mg/kg) while the highest accumulation for Cu (1977 ± 293 mg/kg) and Pb (1096 ± 75 mg/kg) were recorded in the mixed Cd + Pb + Cu + Zn + EDTA treatment, respectively. Generally, the overall heavy metal accumulation trends of Vetiver grass were in the order of Zn >>> Cu > Pb >> Cd for all treatments. Furthermore, both upper roots and tillers of Vetiver grass recorded high tendency of accumulation for appreciably greater amounts of all heavy metals, regardless of single and/or mixed metal treatments. Thus, Vetiver grass can be recommended as a potential phytoextractor for all types of heavy metals, whereby its tillers will act as the sink for heavy metal accumulation in the presence of EDTA for all treatments.

Accumulation of uranium and heavy metals in the soil-plant system in Xiazhuang uranium ore field, Guangdong Province, China.

Plants that have grown for many years in the special environmental conditions prevailing in mining areas are naturally screened and show strong capacity to adapt to their environment. The present study investigated the enrichment characteristics of U and other heavy metals (As, Cu, Pb, Mn, Mo, Zn, Cd, Co, and Ni) in the soil-plant system in Xiazhuang uranium mine. Four dominant plants (Castanopsis carlesii, Rhus chinensis, Liriodendron chinense, and Sapium discolor) and soil samples were collected from the mined areas, unmined areas, and background areas away from the ore field. U, As, Cu, Pb, Mn, Mo, Zn, Cd, Co, and Ni concentrations were analyzed by ICP-MS. The results demonstrate that (1) The highest concentrations of U (4.1-206.9mg/kg) and Pb (43.3-126.0mg/kg) with the geoaccumulation index (Igeo) greater than 1 show that they are the main soil pollutants in the research area. (2) The biological accumulation coefficient (LBAC) values for Cd, Mn, and Cu are greater than zero in S. discolor, L. chinense, and C. carlesii and these three plants indicate that they can be used for remediation of the soil in the ore field. (3) R. chinensis inhibits the accumulation of heavy metals and shows sensitive pigment responses to the accumulation of U in the leaves. L. chinense has the strongest enrichment effect on heavy metals but exhibits weak biochemical responses under U stress. C. carlesii demonstrates strong adaptation to U and can maintain healthy pigment characteristics in case of high U enrichment. (4) S. discolor, L. chinense, C. carlesii and R. chinensis have strong tolerance to U toxicity and different biochemical responses.