Biological Concentration Factor Research Articles

Investigation of heavy metals uptake in root-shoot of native plant species adjoining wastewater channels.

Metal pollution in water, soil, and vegetation is an emerging environmental issue. Therefore, this study investigated the abundance of heavy metals (HMs) within roots and shoots of native plant species i.e., Bromus pectinatus, Cynodon dactylon, Poa annua, Euphorbia heliscopa, Anagallis arvensis, and Stellaria media grown in the adjoining area of municipal wastewater channels of a Pakistani city of Abbottabad. HMs concentrations (mg L-1) in municipal wastewater were: chromium (Cr) (0.55) > nickel (Ni) (0.09) > lead (Pb) (0.07) > cadmium (Cd) (0.03). Accumulation of HMs in both roots and shoots of plant species varied as B. pectinatus > C. dactylon > P. annua > E. heliscopa > A. arvensis > S. media. Irrespective of the plant species, roots exhibited higher concentrations of HMs than shoots. Higher amount of Cr (131.70 mg kg-1) was detected in the roots of B. pectinatus and the lowest amount (81 mg kg-1) in A. arvensis, Highest Cd concentration was found in the shoot of B. pectinatus and the lowest in the E. heliscopa. The highest concentration of Ni was found in the roots of S. media (37.40 mg kg-1) and the shoot of C. dactylon (15.70 mg kg-1) whereas the lowest Ni concentration was achieved in the roots of A. arvensis (12.10 mg kg-1) and the shoot of E. heliscopa (5.90 mg kg-1). The concentration of HMs in individual plant species was less than 1000 mg kg-1. Considering the higher values (> 1) of biological concentration factor (BCF), biological accumulation co-efficient (BAC), and translocation factor (TF), B. pectinatus and S. media species showed greater potential for HMs accumulation than other species. Therefore, these plants might be helpful for the remediation of HM-contaminated soil.

The capacity of Plectranthus sp. to perform phytoremediation on heavy metal mercury (Hg) in the tailing of gold processing industries

Sludge (tailing), a waste product of the amalgamation process used in the mining of gold, contains a high concentration of the heavy metal mercury (Hg). It is well known that mercury builds up in large quantities in Plectranthus sp. herbaceous plants in the Pancurendang Village Small-Scale Gold Mining area. The study intends to: 1) quantify the amounts of mercury present in plant organs and media tailing during phytoremediation treatment; 2) examine the mechanisms and capacities of plant phytoremediation using values of the Biological Accumulation Coefficient (BAC), Biological Concentration Factor (BCF), and Translocation Factor (TF); and 3) determine the impact of percentage variations in tailing and time on Plectranthus sp.’s capacity to accumulate mercury. On a lab scale, phytoremediation of tailings is done with concentrations of 0%, 30%, 50%, and 100%. Planting medium is combined with dried tailings. Pots are used for phytoremediation, and the residence times are 10, 20, and 30 days. With the use of a mercury analyzer, the amount of mercury present in plant media, roots, and shoots is determined. Using the BAC, BCF, and TF values, the mathematical calculation of phytoremediation ability is performed. Hg content ranged from 1.82 to 16.23 ppm in shoots and 5.15 to 37.19 ppm in roots. Throughout the course of treatment, the tailings Hg concentration varied between 13.18 and 220.05 ppm. Plectranthus sp. is categorized as a medium accumulator with a phytoextraction mechanism, according to the analysis’s findings. Hg phytomining is possible with Plectranthus sp., the TF value is 2.38. Within 10 days, Plectranthus sp. most effectively accumulates 50% Hg in tailings.

Metal and nutrient uptake by natural wetland plants in a tropical man-made wetland of Sri Lanka

Phytoremediation of contaminated soil is an environmentally-friendly approach to minimize the impacts of nutrients and heavy metals on an ecosystem. Hence, selecting appropriate plants with phytoextraction potential is paramount to remediatie contaminated soils. This study aimed to investigate the nutrient and metal contents of four natural aquatic plants, including Cyperus rotundus, Eleocharis dulcis, Typha angustifolia, and Schoenoplectus grossus. They were grown in the meadow of a small reservoir in Sri Lanka to assess their phytoextraction ability using plant and soil samples collected at 32 sampling points in the meadow. Their biological concentration (roots/soil), accumulation (shoots/soil), and translocation (shoots/roots) factors were determined to assess element mobility and phytoextraction ability. Total K, Na, Mg, Ca, Zn, Cu, Fe, Mn, As, Pb, and Cd contents of plants and soil samples were measured using an Inductivity Couple Plasma Optical Emission Spectrophotometer. ANCOVA was used as a statistical test to assess the best plant type in terms of nutrient and metal absorption. Plant shoots exhibited significantly greater values for P, Na, Mg, Zn, Cd, and Fe than their roots. Their biological concentration, accumulation and translocation factors were not different among the four plant species. However, these values were >1 for all the species, indicating their potential to be used as hyperaccumulators. T. angustifolia, with its high potential for nutrient and metal accumulation and the highest aesthetic appeal, was selected as the best overall wetland species for phytoremediation purposes.

Improving vanadium removal from contaminated river water in constructed wetlands: The role of arbuscular mycorrhizal fungi

Industrial activities pose a significant ecological risk to water resources as they pollute surrounding waters with vanadium (V). Although the contribution of plants and substrates to V removal in constructed wetlands (CWs) has been reported, the role of arbuscular mycorrhizal fungi (AMF) is unclear. The aim of the present study was to investigate the role of AMF in V removal in CWs and to elucidate the underlying mechanisms. Reed plants (Phragmites australis) were inoculated with an AMF strain (Rhizophagus irregularis) in CW columns, creating AMF-inoculated (+AMF) and non-inoculated (-AMF) treatments. Three levels of influent V concentrations (low: 0.50 mg L−1, medium: 1.14 mg L−1 and high: 1.52 mg L−1) were examined. The + AMF treatment showed higher V removal (60%–98%) than the control (40%–82%) in all three conditions, although the difference was not significant in some cases. The mean mycorrhizal effects were 75%, 19%, and 28% for low, moderate, and high influent V concentrations, respectively. The +AMF treatment showed a higher GRSP-bonded V concentration (5.5 mg g−1) than the -AMF treatment (4.0 mg g−1). Furthermore, +AMF treatment showed larger plants with higher V concentrations in their tissues, accompanied by increased biological concentration factors and biological accumulation factors. Given the remarkable positive effect of AMF on V removal, our study suggests that treating AMF in CWs is a worthwhile approach.

Lithogeochemical characteristics and potential hyperaccumulator identification as phytomining agent at the Ratatotok gold mine, Indonesia

In the future, phytomining will be an environmentally friendly alternative mining technology. Therefore, the exploration of vegetation types having the potential as hyperaccumulators in gold phytomining needs to be carried out. This study aimed to (1) investigate the effect of rock/soil mineralogy characteristics and Au content on the diversity of vegetation types at gold mine sites, and (2) determine the type of potential hyperaccumulator vegetation as a phytomining agent based on the Biological Concentration Factor (BCF). This study was conducted at the Ratatotok gold mine in North Sulawesi Province, Indonesia. The sampling locations consisted of 3 sites, i.e., Bulex, Yance, and Leon, and each site consisted of 5 sampling plots. Soil samples were taken from each sampling plot and then tested for gold content using the ICP-MS method and mineral content using the XRD method. Mineralized bedrock samples were also taken for mineralogical analysis through petrography. Data analysis of soil geochemistry was carried out descriptively. Quantitative descriptive analysis was also carried out to determine the dominant type of vegetation, which was potential for hyperaccumulators at the mine site. The results showed that gold content in the soil affected the diversity of vegetation, which was possibly due to gold stress, which affected plant growth. Based on the BCF value, three local plant species having potential as gold hyperaccumulators with moderate bioaccumulation ability (BCF>0.1-1) were found, namely Pteris vittata, Syzygium aromaticum, and Swietenia mahagoni. However, the use of these plants as phytomining agents requires further research.

Ecological Risk Evaluation of Heavy Metals in Soils near a Water Dam in Baljurashi, KSA, and Their Accumulation in Dodonaea viscosa

Soil’s contamination with heavy metals is a serious issue, and assessing their levels, regulating their sources, and finding cost-effective technology to limit their toxic effect and soil cleanup are of high priority. The focus of this study was to find out the extent of priority hazard heavy metal contamination in soils close to the Al-Janabeen water reservoir dam in Baljurashi, KSA, and the extent of their accumulation in the Dodonaea viscosa Tacq plant. Soil and plant samples were analyzed for heavy metal concentration using inductively coupled plasma spectroscopy (ICPS). Quantitative single and integrated contamination indices were used to characterize and evaluate the degree of heavy metal contamination in soils. The biological concentration factor (BCF) and the translocation factor (TF) were utilized to determine the extent of transfer and accumulation of heavy metals in the D. viscosa plant. Soil analysis showed the presence of Mn, Cu, Zn, Co, Cr, and Pb among the prioritized heavy metals with Cu, Zn, and Pb values being higher than those in natural background levels. The mean concentration order was Fe > Mn > Zn > Cu > Pb > Cr > Ni > Cr > Co. The single contamination indices’ quantification indicated marked contamination due to Mn, Zn, Cu, Co, Cr, and Pb elements. While integrated contamination factors’ computation showed low ecological risk due to accumulative metals of concern, Nemerow’s index (NI) showed that Cu, Zn, and Pb were the three most abundant pollutants in the examined soils. Analysis of plant parts showed the presence of Mn, Cu, Ni, Zn, Co, Cr, Cd, and Pb at varying quantities in various plant sections. Both BCF and TF factors were less than one, indicating that the D. viscosa plant was limited in its ability to phytoextract and accumulate the metals from the soil. This study suggests more research to locate suitable native plants for phytoremediation and soil cleaning is required in addition to the appropriate planning and management of landfills in order to ensure agricultural sustainability.

Remediation of soil contaminated with tris-(1-chloro-2-propyl) phosphate using plant and microorganism combined technology: A greenhouse experiment

The remediation of tris-(1-chloro-2-propyl) phosphate (TCIPP) -contaminated soil by the plant (ryegrass, Lolium perenne L.) and microorganism (TCIPP degrading bacteria, Ochrobactrum sp. DT-6) alone or in combination was investigated in this study. TCIPP can inhibit the growth and development of ryegrass and there is a clear dose-effect relationship. Inoculation with strain DT-6 was able to mitigate the toxic influence of TCIPP on ryegrass, but this mitigation effect was not significant. TCIPP in the soil was relatively easy to be uptaken by the ryegrass roots and migrated to the shoots. Furthermore, as the soil TCIPP concentration rose, the concentration of TCIPP in ryegrass also exhibited a corresponding increase. The biological concentration factor (BCF) ranged from 0.33 to 1.88 and the biological accumulation coefficient (BAC) ranged from 0.54 to 3.98. They all significantly decreased with higher soil TCIPP concentrations. The translocation factor (TF) values ranged from 1.55 to 2.34. Inoculation of strain DT-6 significantly reduced TCIPP concentrations in ryegrass roots, stems, and leaves as well as the values of BAC and BCF under low and medium TCIPP concentration treatment conditions, but the effect on TF values was not remarkable. The planting of ryegrass significantly raised the elimination of TCIPP from the soil to 64.6–93.3%, but the influence of inoculation with strain DT-6 on the remediation effect by ryegrass was not significant. The percentage contribution of phytoextraction to the elimination of TCIPP from soils ranged from only 0.64–5.23%.

The national maize hybrid as a potential mediator in the contamination of the food chain with heavy metals

ABSTRACT The ability of the maize hybrid ZP666 to uptake cadmium (Cd), chromium (Cr), copper (Cu), nickel (Ni), and lead (Pb) from artificially contaminated soil in a pot experiment was investigated. The applied ICP-OES methods are of satisfactory accuracy (Recovery values from 88.9 to 103.0%) and negligible matrix effect (slope ratio from 0.95 to 1.11). The determined contents of the investigated heavy metals in plant parts of maize, the mass of roots, stems and leaves, the height of the aboveground parts as well as the BCF (Biological Concentration Factor), MR (Mobility Ratio), TF (Translocation Factor) and EF (Enrichment Factor) values show the highest influence of Cd. The strongest negative effect on mass (roots 59.7%, stems 56.6%, and leaves 42.5%) and on the height of aboveground parts (13.5%) was observed in the unit treated with Cd. Also, BCF and TF (stem/root) are higher than 1 only for Cd (1.65 and 1.07, respectively) and the highest EF values are for Cd in roots in units treated with Cd and with a mixture of heavy metals (37.30 and 24.04, respectively ZP 666). MR values were less than 1 in all cases. The results obtained are useful for tracing the migration of heavy metals from the roots to the aboveground parts as well as the potential of plant parts for the enrichment of added heavy metals through possible synergistic or antagonistic interactions.

Potentially harmful elements pollute soil and vegetation around the Atrevida mine (Tarragona, NE Spain)

Mining activity is one of the main sources to pollute soil, water and plants. An analysis of soil and plant samples around the Atrevida mining area in Catalonia (NE Spain) was preformed to determine potentially harmful elements (PHEs). Soil and plant samples were taken at eight locations around the mining area. The topsoil (0–15 cm) samples were analysed for physico-chemical properties by standard methods, by ICP-MS for Cd, Co, Cr, Cu, Fe, Ni, Pb and Zn, and were microwave-digested. Plant, root and shoot samples were digested separately, and heavy metals were analysed by AAS. Translocation factor (TF), biological concentration factor (BCF) and biological accumulation factor (BAF) were determined to assess the tolerance strategies developed by native species and to evaluate their potential for phytoremediation purposes. Soil pH was generally acid (5.48–6.72), with high soil organic matter (SOM) content and a sandy loamy or loamy texture. According to the agricultural soil values in southern Europe, our PHEs concentrations exceeded the toxicity thresholds. The highest root content of the most studied PHEs appeared in Thymus vulgaris L. and Festuca ovina L., while Biscutella laevigata L. accumulated more PHEs in shoots. The TF values were > 1 in B. laevigata L., but BAF obtained < 1, except Pb. B. laevigata L., and can be considered potentially useful for phytoremediation for having the capacity to restrict the accumulation of large PHEs amounts in roots and Pb translocation to shoots.

Differences in selenium concentration and bioavailability between paddy and dryland soils of China: A study based on literature collection and field sampling.

Lack systematic understanding of differences in environmental behavior of selenium between paddy and dryland soils affects Se biofortification and leads to human Se-related health risks. Therefore, this study investigated differences in Se concentration and bioavailability between paddy and dryland soils using data collected from literatures and field sampling. Our analysis showed paddy soil Se concentration in Se-rich area of China was significantly lower than that in dryland soil. Selenium biological concentration factor of rice grain (BCFgrain) in Se-rich area was lower than that in non-Se-rich area attributed to higher percentage of selenite in available Se. Concentration and percentage of available Se were in dryland soil lower than those in paddy soil and this affected BCFgrain of maize, whereas BCFgrain of rice was further influenced by its Se transport capacity. The ranges of Se concentration in Se-rich paddy (0.14-3.63mgkg-1) and dryland (0.45-1.17mgkg-1) soils were derived using a linear regression model. The current soil Se concentration evaluation standard was only suitable for dryland but overestimated Se-deficiency and Se-toxicity levels in paddy field. The present study provides theoretical foundations for understanding Se concentrations and bioavailability in soils and selecting efficient and safe approach on cultivated land use.

Heavy Metals Accumulation and Phytoremediation Ability of Onion (Allium cepa) and Garlic (Allium sativum) Grown on Contaminated Soils from Challawa Industrial Estate, Kano, Nigeria

This work was designed to assess and compare the heavy metals accumulation and phytoremediation ability of some allium species (Garlic; Allium sativum and Onion; Allium cepa) grown on two different soils (contaminated and Control soils) using standard methods. Heavy metals (of Cr, Fe, Mn, Ni, Pb, and Zn) Concentrations (mg/Kg) were determined using atomic absorption spectrophotometry (AAS Model: 210VGP). Plants growth and biomass production were assessed. Biological concentration factors (BCF) and translocation factors (TF) were calculated. The mean levels of elements obtained ranged widely from 0.55 mg/Kg Ni to 1830.64 mg/Kg Fe. The results showed that onion accumulated higher concentrations of all the heavy metals compared to garlic with exception of Zn. However, the differences in heavy metal concentrations where significant only in Cr and Mn. Phytoremediation efficiency indices (BCF and TF) showed a similar trend for both onion and garlic. The mean BCF values of Pb, Cr, Zn, Mn and Fe in onion were generally high &gt; 1. Ni and Pb had their mean TF values greater than 1. Thus, onion can be used as potential phytoextraction plant. The similarities in most of these metal accumulation trends, BCF and TF between onion and garlic might be due to their being similar species with similar physiological features and from the same family.

Environmental sustainability and resilience in a polluted ecosystem via phytoremediation of heavy metals and plant physiological adaptations

Natural Ecosystems are being degraded significantly due to increasing industrial pollution. Marble pollution is one of them. It was hypothesized that such a polluted ecosystem host unique set of plant species growing and tolerating the level of the pollution they dwell in. These can be used as phytoremediators successively, once the level of their tolerance is determined for environmental sustainability and resilience. The current research work was aimed to assess the phytoremediation ability of the selected resistant plant species by studying their physiological adaptations in the Marble Waste Polluted Ecosystem (MWPE) of northern Pakistan. Quantitative Ecological Techniques (QET) were adopted to sample the vegetation of polluted zones, initially. Indicator species were identified using Indicator Species and Total Importance Value, Indices. Topmost indicator plants were further evaluated for environmental sustainability and resilience based on indicator species analysis and a higher importance value index in the region for their phytoremediation abilities using Biological Concentration Factor (BCF), Translocation Factor (TF) and Bioaccumulation coefficient (BAC) analyses using atomic absorption spectrophotometric techniques. Physiological responses i.e., Proline accumulation and chlorophyll contents (a, b and carotenoids) for each indicator plant species were recorded and examined using standard experimental protocols. Atomic absorption spectrophotometry was also used to assess heavy metals concentration. All the collected data were analyzed through Structural Equation Modeling, Mixed effect modeling and Regression analysis using R software. Preliminary results showed that out of 220 species, 19 indicator plants, i.e., Adiantum capillus-veneris, Ailanthus altissima, Albizia lebbeck, Calotropis procera, Cynodon dactylon, Datura innoxia, Debregeasia salicifolia, Desmostachya bipinnata, Dodonaea viscosa, Erigeron bonariensis, Ficus carica, Morus alba, Morus nigra, Parthenium hysterophorus, Persicaria glabra, Ricinus communis, Setaria viridis, Tamarix aphylla and Withania somnifera were the significant phytoextractor and phyto-stabilizer of potential toxic elements (Cr, Ni, Cu, Mn, Zn, Fe, Co, Cd, Ca and Mg) based on bioaccumulation coefficient, translocation and biological concentration factors. These indicators increase the accumulation of proline osmolyte and decrease chlorophyll-a, chlorophyll-b and total carotenoids as a defense or survival mechanism against pollution. These results were reconfirmed through Structural Equation Modeling, Mixed Effect Modeling and Bivariate Regression. It was concluded that the indicator plants have a significant role in the cleaning of ornamental rocks pollution and hence in the environmental sustainability and resilience. It is recommended that these indicator plants can be grown to remediate the heavy metals or PTEs released from the MWPE and their vicinities for better environmental management and pollution control in the subtropical regions of the world.

Lead-induced modification of growth and yield of Linum usitatissimum L. and its soil remediation potential

This study was designed to evaluate the pre-reproductive and reproductive responses of Linum usitatissimum L. (flax, linseed plant) to different levels of Pb in the soil. Flax seeds were sown in garden soil-filled earthen pots and treated with three different levels of lead as lead chloride (150, 450, and 750 mg Pb kg−1 soil) except control, and each treatment was replicated three times. Growth and reproductive parameters and photosynthetic pigments were significantly reduced (p ≤ 0.05) for all treatments. Quantitatively, Chlorophyll b content decreased more than chlorophyll a and the amount of proline content in the leaves increased in lockstep with the increase of Pb levels in the soil. Pb was found in substantial amounts in the roots, shoots, and seeds. The pattern of Pb accumulation in different organs was root > shoot > seeds. Pb levels in seeds obtained from 750 mg Pb kg−1 soil-treated plants exceeded the permissible limits. Biological concentration factor (BCF), biological accumulation coefficient (BAC) and translocation factor (TF) values showed that roots of L. usitatissimum absorbed and accumulated a substantial quantity of Pb but translocated only a fraction of that to the shoots. Therefore, L. usitatissimum L. can be used in phytostabilization rather than phytoextraction of Pb.

An integrated geochemical and mineralogical investigation on soil-plant system of Pinus halepensis pioneer tree growing on heavy metal polluted mine tailing

ABSTRACT The plant species Pinus halepensis grows spontaneously on heavily polluted mine tailings dumps of Campo Pisano (Sardinia, southwestern Italy). The area is characterized mainly by Zn, Pb, and Cd. Sampling campaign was done, related to soils and plant materials (roots, barks, wood, and needles), aimed at evaluating the main mineralogical characteristics, metal content, plant accumulation, and translocation behavior. The polluted substrates were composed of pyrite, dolomite, calcite, quartz, gypsum, and barite with iron sulphate, and iron oxide. Zn ore minerals (smithsonite) and muscovite detected mostly in the deeper soil layers. Zn was the most abundant metal in the substrate as well as plant tissues. Roots accumulated high metal concentrations (664.65-2710 Zn, 58.39-735.88 Pb, and 4.86-11.02 mg kg−1 Cd) reflecting high metal contamination in soil. The biological accumulation and translocation values were reported below one for all plant tissues. Pb, Zn and Cd Translocation Factor (TF) in needles ranged 0.03-0.32, 0.03-0.19, 0.04-0.14. Biological Concentration Factor (BCF) estimated up to 0.17, 0.18, and 0.19, respectively. Results indicate that P. halepensis is an excluder, tolerates high Zn, Pb, and Cd concentrations, restricts their accumulation and translocation to the aerial parts and may be applied for long-term phytostabilization and revegetation processes in abandoned mine tailing sites.

Field assessment of trace element phytoextraction by different Populus clones established on brownfields in southern Quebec (Canada)

Fast-growing hybrid poplars have been tested for their potential to remove trace elements (TE) from polluted soil in several temperate regions. Despite their potential, they have rarely been tested in countries with a cold temperate climate. The current study screened four different Populus hybrids for phytoextraction of four TEs (i.e., As, Cu, Pb, and Zn) on an abandoned brownfield site in southern Quebec (Canada). The main results showed that under the current experimental conditions, the most important traits determining the actual phytoextraction rate are Biological Concentration Factor (BCF) and TE accumulation in the aboveground biomass, rather than biomass productivity. Although the overall performance of the chosen hybrids was rather poor, the presence of poplar stands enhanced the movement of mobile contaminants in soil, which led to an increase in their concentration in the root zone. This aspect suggests possible strategies for using these plants with high transpiration rates in future phytoremediation projects, including either possible rotation with more effective TE phytoextractor plants (e.g., hyperaccumulators) that can remove high TE amounts that have migrated from the deeper soil layers following poplar plantation, or phytostabilization.

Determining the Mobility of some Essential Elements in Saffron (Crocus sativus L.) by the Neutron Activation Analysis

The main purpose of this investigation is to evaluate the concentrations of six essential metals (Na+, Mg2+, K+, Ca2+, Fe2+ and Zn2+) in saffron and a farm soil using the neutron activation analysis (NAA) as a nuclear spectrometry method. The stratified random sampling method was used here. The NAA results showed the well uptake of Mg2+, K+, Ca2+, Fe2+, and Zn2+ in saffron, which is lower than the toxicity range. Based on the contamination factor and geoaccumulation index, soil contamination levels were determined uncontaminated by Zn, moderately contaminated by Na+ and Fe2+, and strongly contaminated by Ca2+, K+, and Mg2+. Results of the contamination degree and pollution load index indicated moderately/strongly soil contamination and a moderate geometric mean of the contamination index. The Na+ enrichment factor (EF) showed a minimal man-made impact on sodium enrichment. Saffron cultivation has likely caused more accumulations of Mg2+, K+, Ca2+, and Fe2+, as well as a considerable deficiency of Zn2+ in the soil, based on EFs. The biological concentration factor showed a significant zinc accumulation by the corm of saffron. There was well translocation from corm to all the aerial tissues for K+. Also, sodium adsorption ratio, exchangeable sodium percentage, pH, and electrical conductivity evaluated the non-salinity level of soil in all saffron farms.

Effects and mechanism of igneous rock on selenium in the tropical soil-rice system in Hainan Province, South China

To illuminate the migration and transformation of selenium (Se) in the igneous rock-soil-rice system, 285 pairs of rhizosphere soil and rice samples were collected from the granitoid and basalt areas in Hainan Province, South China. The contents of Se in soils derived from granitoid and basalt are, respectively, 0.19±0.12 mg/kg and 0.34±0.39 mg/kg, which are much higher than Se contents in granitoid and basalt. Selenium shows remarkable enrichment from granitoid and basalt to soils. The mobile fraction of Se in soils derived from granitoid is 0.0100±0.0034 mg/kg, which is significantly higher than that of basalt (0.0058±0.0039 mg/kg). Although soil derived from basalt shows higher Se contents, Se contents in rice samples, mobile fractions of Se in soils, and biological concentration factor (BCF) is similar or even lower than that from granitoid. Basalt consist of calcic plagioclase and pyroxene, and are much richer in Fe, Al, and Ca than granitoid. Correspondingly, the basalt-derived soils have higher goethite, hematite, kaolinite, cation exchange capacity (CEC) content, and higher pH than the granitoid-derived soils, which result in higher adsorption capacity for Se and relatively lower Se bioavailability. Soils derived from granitoid and basalt in tropical regions are beneficial to produce Se-rich rice.© 2022 China Geology Editorial Office.

Phytoremediation of Heavy Metals Using Spinach (Amarantus spinosa) Grown on Contaminated Soils

This work was designed to assess the phytoremediation ability of Spinach (Amarantus spinosa) grown on two different soils (contaminated soil obtained from Chalawa Industrial Estate, Kano, and control soil obtained from Biological Garden of Umaru Musa Yar’adua University, Katsina). Concentrations (mg/Kg) of Cr, Fe, Mn, Ni, Pb, and Zn were determined using atomic absorption spectrophotometry (AAS). Biological concentration factors (BCFs) and translocation factors (TFs) were calculated. The mean levels of metals obtained ranged widely from 0.23 mg/kg Ni to 1971.37 mg/kg Fe. Highest mean levels of Cr (97.74 mg/kg), Fe (1971.37 mg/kg), Mn (78.22 mg/kg), Zn (170.60 mg/kg) were contained in the leaf of the spinach samples, whereas Ni (1.98 mg/kg) and Pb (14.24 mg/kg) were contained in the root of the spinach samples. The results showed a significant level (p&lt;0.05) of all the metals analysed in the spinach samples grown on the polluted soil compared with those grown on the control soils. Amongst the metals, Ni and Pb were found to have the lowest (0.50) and highest (7.57) BCF values respectively. The lowest and highest TF values were found to be on Cr (0.32) and Zn (1.17) respectively. Consequently, Higher BCF and TF values were found for Pb and Zn and this resulted in greater extraction ability of Pb and Zn. The spinach ability to extract Fe and Ni was found to be poor.

Lead, zinc tolerance mechanism and phytoremediation potential of Alcea rosea (Linn.) Cavan. and Hydrangea macrophylla (Thunb.) Ser. and ethylenediaminetetraacetic acid effect.

In this study, we aimed to elucidate the defense mechanism of Alcea rosea (Linn.) Cavan. and Hydrangea macrophylla (Thunb.) Ser. against the single and compound toxicity of lead (Pb) and zinc (Zn) along with the synergistic effect of ethylenediaminetetraacetic acid (EDTA) in accumulation of metals in these two species. The two plant species were subjected to single metal treatment (Pb 1000mgkg-1, Zn 600mgkg-1) and compound metal treatment (Pb 1000mgkg-1 + Zn 600mgkg-1) in a greenhouse. Besides, different levels of EDTA were applied (2.5, 5.0, and 10.0mmolkg-1) with compound metal treatment. Several physiological and biochemical parameters, including plant photosynthetic parameters, enzymatic antioxidant system, accumulation concentration of metals, and subcellular distribution were estimated. The results showed that the antioxidative enzymes, proline, root morphological changes, and metal localization all played important roles in resisting Pb and Zn toxicity. A notable difference was that Zn was concentrated in the roots (58.5%) of H. macrophylla to reduce the damage but in the leaves (38.5%) of A. rosea to promote photosynthesis and resist the toxicity of metals. In addition, Zn reduced the toxicity of Pb to plants by regulating photosynthesis, Pb absorption and Pb distribution in subcells. The biological concentration factors (BCF) and translocation factors (TF) for Pb in two plants were less than 1, indicating that they could be considered as phytostabilizators in Pb-contaminated soils. Moreover, EDTA could enhance the enrichment and transport capacity of Pb and Zn to promote the phytoremediation effect. In summary, both plants have a certain application potential for repairing Pb-Zn-contaminated soil.

Heavy Metal Effects on Biodiversity and Stress Responses of Plants Inhabiting Contaminated Soil in Khulais, Saudi Arabia.

Simple SummaryDespite its high organic matter content, sewage sludge contains significant quantities of heavy metals, including those designated as hazardous, such as cadmium, nickel, chromium, mercury, copper, lead, and zinc, which, as a consequence, have a negative impact on living organisms. The current research sought to study the effect of dumping sludge, as one of the sources of pollution with heavy metals, on biodiversity and to assess the bioremediation and stress defense strategies of a tolerant plant species. The obtained results showed that soil pollution by heavy metals has a substantial influence on plant diversity. The selected species, Amaranthus retroflexus L., showed a high biological concentration factor (BCF) and low translocation factor (TF) for Cu, As and Ni. The stress defense strategies of A. retroflexus grown under complex heavy metals contamination are studied and discussed.Accumulation of heavy metals in soil is becoming an increasingly serious eco-environmental problem. Thus, investigating how plants mitigate heavy metal toxicity is necessary to reduce the associated risks. Here, we aimed to assess the bioremediation and stress defense strategies of tolerant plant species grown under complex heavy metals contamination. To this end, a field study was conducted on the vegetation cover of sites with different soil pollution levels. Forty-two plant species that belong to 38 genera and 21 families were identified. The pollution had a significant impact on plant richness in the polluted sites. Out of several screened plants, Amaranthus retroflexus L. was selected because of its high relative density (16.7) and a high frequency (100%) in the most polluted sites. The selected species showed a high biological concentration factor (BCF) and low translocation factor (TF) for Cu, As and Ni. To control the heavy metal-induced oxidative damage, A. retroflexus invested in detoxification (metallothionein and phytochelatins, glutathione and glutathione-S-transferase (GST). At the organ level, oxidase damage (H2O2, lipid and protein peroxidation) was observed, particularly in the roots. To mitigate heavy metal oxidative stress, antioxidant mechanisms (e.g., tocopherols, glutathione, peroxidases, catalase, peroxide dismutase and ASC-GSH cycle) were upregulated, mainly in the roots. Overall, our results suggested the potentiality of A. retroflexus as a promising bioremediatory and stress-tolerant plant at the same time; moreover, defense and detoxification mechanisms were uncovered.