Ratio Of Metal Concentration Research Articles

Phytoremediation Potential of Macrophytes of Urban Waterbodies in Central India.

Background.India's rapidly increasing population and growing urbanization pose a great challenge for wastewater treatment efforts, leading to increased pollution of surrounding waterbodies.Objectives.A field sampling-based study was conducted to analyze water quality, heavy metals and bioconcentration and bioaccumulation in the roots and shoots of naturally growing vegetation in an urban lake, Laxmi Taal. The lake receives domestic sewage from Jhansi city in Central India.Methods.Temperature, pH, electrical conductivity, turbidity, and water-soluble ions were measured with appropriate instruments. Plant accumulation of metals was measured with the bioconcentration factor (BCF), the ratio of metal concentration in the root to wastewater. The translocation factor (TF) was estimated as the ratio of metal concentration in the shoot to the root.Results.Water quality and heavy metal concentrations were found to be within the prescribed limit as per Indian standards IS-2296 “D”. In the present study, BCF was assessed to be >1 and the plants Typha angustifolia and Echhornia crassipus were determined to be accumulator plants. The TF study revealed that translocation of all the metals studied were significant, except for manganese (Mn), where concentration was found to be below detection limit.Conclusions.The present study validated that Typha angustifolia and Echhornia crassipus could be used for bioremediation purposes in cases of urban waterbodies receiving varying amounts of domestic wastewaters which have relatively limited concentrations of toxic metals.Competing Interests.The authors declare no competing financial interests

Uptake of Trace Elements in Leaves of the Larrea Tridentata (DC.) Coville in Desert Washes of an Arid Environment

Trace elements (As, Cd, Cr, Pb, Ba, Fe, Al, Mn and Ba) were uptaken by the leaves of the creosote bush (Larrea tridentata (DC.) Coville) in Nelson, Nevada, although at low concentrations. Samples were collected up-gradient of the mine tailings, the tailings, and down gradient from the source to measure spatial distribution. Data show that trace elements (As, Ba, Cr, Hg, Se) enter L. tridentata through root tissues, migrating to leaf tissue, but at significantly lower levels than that of the source sediments. Metalloid (As and Se) concentrations in the leaf tissues ranged from non-detect to greater than 44 mg kg−1 As and non-detect to over 34 mg kg−1 Se. For trace metals, Hg ranged from non-detect to 0.14 mg kg−1; Ba from 1.74 to 4.12 mg kg−1; and Cr from non-detect to 6.18 mg kg−1 while Ag, Cd, and Pb were not detected in the plant leaves. When comparing the ratio of sediment metal concentration to plant metal concentrations, the Techatticup Wash contained the highest levels of trace elements in the leaves of the L. tridentata, followed by the Carnation Wash, with the Eagle Wash containing the lowest concentrations of trace elements.

Trace elements removal ability and antioxidant activity of Phragmites australis (from Algeria)

In this study, roots, stems and leaves of the worldwide distributed macrophyte Phragmites australis (common reed) were tested as potential removal and biomonitors of trace elements contamination in sediment. In particular, the concentrations (100, 200, and 500 mg/kg) of the following elements were analyzed: Zn, Cu, Pb, and Fe. Results showed that the amount of concentrations in plant tissues is significantly (p ≤ 0.01) dependent on the kind of organ and element. Trace element concentrations decreased according to the pattern of Fea (Rootsa > Stemsb > Leavesb) > Znb (Roota > Leavesb > Stemsc) > Cuc (Rootsa > Leavesb > Stemsc) > Pbc (Rootsa > Stemsb > Leavesc), as well as the roots acted as the main centers of bioaccumulation for all elements studied, and stems as the transit organs for translocation from roots to leaves. The major mechanisms employed by the plant were probably phytostabilization on the basis of the calculated Biological Concentration Factor (BCF – metal concentration ratio of plant root to soil); and Translocation Factor (TF – metal concentration ratio of plants roots to above ground part). Finally, due to the low scavenger effect of the radical DPPH, we excluded the hypothesis of the use of antioxidant mechanism in the tolerance of metals.

Heavy metals content and distribution in basil (Ocimum basilicum L.) as influenced by cadmium and different potassium sources

Despite the fact that cadmium (Cd) is a non-essential element for plants, it can influence nutrients and affect human health. Potassium (K) can influence the transportation of heavy metals (HMs) in soil-plant systems. Here, a greenhouse experiment was conducted to evaluate the effect of Cd and K fertilizers on the different partitioning forms of HMs, their concentrations, uptake in the shoots and roots of Ocimum basilicum. Treatments comprised 2 levels of Cd (0 and 40 mg kg−1) and three levels of K (0, 100, and 200 mg kg−1) from three sources, i.e. KCl, K2SO4, and K-nano-chelate. 40 mg Cd kg−1 increased the shoot (above ground parts) Cd concentration. Addition of K as KCl, K2SO4, and K-nano-chelate increased the presence of Cd in shoots by 86, 82 and 76%, respectively, compared to the control. Using the nano-chelate of K can increase the accumulation of Cd in plants grown on contaminated soils to lesser content than that of the other forms of K. Application of 40 mg Cd kg−1 reduced the concentration of Zn, Cu, and Mn in the shoot, but increased shoot Fe concentration. Transfer factor (TF), which is the ratio of metal concentration in shoot to its concentration in root, of the studied HMs, was significantly affected by Cd and K treatments. Therefore, the proper form and dose of chemical fertilizers should be applied in Cd-contaminated soils.

METAL EXPOSURE IN RESPIRABLE & INHALABLE DUST BY THE LOCALITY OF COAL-FIRED POWER PLANT

The surrounding area of the coal-fired power plant are mostly exposed to its chemical contents. The world has witnessed multicases relevant to mortality due to overexposure to coal materials. However, these factor have not been faced by the Malaysians. Still, it is significant to monitor and control the coal-fired power plant exposure. This research aims to identify the dominant metal within the radius of a coal-fired power plant combustion source point. The inhalable and respirable dust are being collected then analysed and calculated its Permissible Exposure Limit (PEL). Later, health impact knowledge is being synchronize withthe obtained data. Hence, built environment at the radius 5km, 10km, 15km and 20km were being observed as well as inhalable and respirable dust. The data was analysed using the ICPMS (Nexion 300x) to trace the concentrations of metals. The metals include Ba, Cr, Cu, Fe, Mn, Ni, Pb, V, and Zn. Generally, the results showed that the total of respirable towards inhalable dust ratio of metal concentration found at Manjung was 88.62%. The highest concentration found inIron was at 4.710 ng m-3 for respirable dust and Zinc for inhalable dust at 7.387 ng m-3; thus, claiming both Iron and Zinc as the dominant metals in Manjung. The pattern of metals concentration found in this research proven that the FGD and ESPs application in Manjung coal-fired power plant contributed in reducing the airborne particles emissions. However, the PEL calculations showed exceeding limits of metals found on site. Hence affecting the human respiratory, cardiovascular and nervous systems. Therefore, new research in developing the policy for the construction of the coal-fired power plant, especially within the radius of residential and public area are in significant need.

METAL EXPOSURE IN RESPIRABLE & INHALABLE DUST BY THE LOCALITY OF COAL-FIRED POWER PLANT

The surrounding area of the coal-fired power plant are mostly exposed to its chemical contents. The world has witnessed multicases relevant to mortality due to overexposure to coal materials. However, these factor have not been faced by the Malaysians. Still, it is significant to monitor and control the coal-fired power plant exposure. This research aims to identify the dominant metal within the radius of a coal-fired power plant combustion source point. The inhalable and respirable dust are being collected then analysed and calculated its Permissible Exposure Limit (PEL). Later, health impact knowledge is being synchronize withthe obtained data. Hence, built environment at the radius 5km, 10km, 15km and 20km were being observed as well as inhalable and respirable dust. The data was analysed using the ICPMS (Nexion 300x) to trace the concentrations of metals. The metals include Ba, Cr, Cu, Fe, Mn, Ni, Pb, V, and Zn. Generally, the results showed that the total of respirable towards inhalable dust ratio of metal concentration found at Manjung was 88.62%. The highest concentration found inIron was at 4.710 ng m-3 for respirable dust and Zinc for inhalable dust at 7.387 ng m-3; thus, claiming both Iron and Zinc as the dominant metals in Manjung. The pattern of metals concentration found in this research proven that the FGD and ESPs application in Manjung coal-fired power plant contributed in reducing the airborne particles emissions. However, the PEL calculations showed exceeding limits of metals found on site. Hence affecting the human respiratory, cardiovascular and nervous systems. Therefore, new research in developing the policy for the construction of the coal-fired power plant, especially within the radius of residential and public area are in significant need.

Comparative assessment on lead removal using micellar-enhanced ultrafiltration (MEUF) based on a type-2 fuzzy logic and response surface methodology

Abstract Treatment of wastewater containing heavy metal ions is a growing challenge due to their coexistence in many industrial effluents. In the present investigation, an interval type-2 fuzzy logic controller (IT2FLC) and Response surface methodology (RSM) based model was developed to predict and modelling of lead removal and permeation flux in separation processes using micellar-enhanced ultrafiltration (MEUF). The Box-Behnken experimental design method investigates the effect of parameters such as surfactant concentration, solution pH and surfactant to metal concentration ratio (S/M) on MEUF performance. The simulation results reveal that the output variables of MEUF performance could be predicted with a high degree of accuracy. Predicting the performance of a MEUF separation process, prior to its ultrafiltration experiment, was introduced as the most prominent feature of this study. This can offer an intelligent method for evaluation of MEUF presentation instead of conventional method, which is both time saving and cost effective.

Phytoremediation of cadmium-, lead- and nickel-contaminated water by Phragmites australis in hydroponic systems

This study was carried out to investigate the phytoremediation ability of Phragmites australis to remove cadmium (Cd), lead (Pb) and nickel (Ni) from contaminated water, to study the effect of pH and salinity on the removal of cadmium, lead, and nickel, and to estimate the pattern of accumulation of these metals in the roots, shoots, and leaves of the plant. The experiments were carried out in a deep-water hydroponic system and 5 mg/L was used as a concentration of each of the heavy metals. The results of the study showed that P. australis had a residual of 7% (93% removal) of cadmium, 5% (95% removal) of lead and 16% (84% removal) of nickel over a 6-week period. In the control experiment, there was a residual of 96% (4% removal) for both cadmium and lead and 89% (11% removal) for nickel over a 6-week period. There was no major effect of pH on the removal of cadmium except at pH10, which led to a slightly reduced removal of cadmium (89% removal). Also, there was no major effect of pH on the removal of lead, however, there was the enhanced removal of nickel at pH10 (93% removal). The major mechanisms employed by the plant were probably phytostabilization on the basis of the calculated Biological Concentration Factor (BCF) – metal concentration ratio of plant root to soil; and Translocation Factor (TF) – metal concentration ratio of plants shoots to roots.

ANALISIS CEMARAN LIMBAH INDUSTRI DAN DOMESTIK TERHADAP BIOTA LAUT DI PERAIRAN KOTA TANJUNGPINANG, PROVIPNSI KEPULAUAN RIAU

Industrial sector is the second priority in development of Tanjungpinang city. The mining industry, processing industry, transport and food are thriving . People has the opinion that a small industry is an industry that does not threaten the environment, so that the small-scale industrial waste are sometimes were forgotten due to it is not significant, and not too dangerous, whereas the B3 waste contained in domestic waste can cause disturbance of marine life and the ecosystem this will have potential to destroy the ecosystem. This study aims to explain the impact of B3 and domestic waste pollution to the environment, especially marine waters to marine life, and feedback to the provincial government for the formulation strategy of the management of the Tanjungpinang waters environment. For the analysis, 10 water samples and 15 aquatic biota was taken at different locations. While the quantitative analysis of pollutants carried by observing a population of the elements of hazardous substances from sediment samples, water and biota network. XRF techniques (X-Ray Fluorescence) and AAS (Atomic Absorbance Spectroscopy) used for the analysis content of the samples. The pollution index determined by compare metal concentration ratio the polluted areas with the standard metal concentration areas that were not polluted. The results show that the coastal water of tanjungpinang have been contaminated by heavy metals (As, Cd, Cu , Pb, Zn, and Ni) with pollution index 2.91 - 5.96. The pollutant Metals were came from the human activities in the shipbuilding industry usually Pb and Zn which is the main component of the paint. While heavy metals such as arsenic (As), Cadmium (Cd), copper (Cu) probably derived from bauxite mining activity, the high levels of nitrate is a sign of agricultural activities that use fertilizers. Unfortunately the rest of it discharged into the coastal waters of Tanjungpinang city, and there is also pollution of E-coli from human waste. Biota that live in the waters of Tanjungpinang have been contaminated by heavy metals (Hg, Zn, and Ar) by bioaccumulation. The related activity of the pollutant was the bauxite processing industry in the past. Heavy metal pollution is highest in Kijing (Pilsbryoconcha exillis) which includes : Hg, Cr, As, Cu, Zn, Ni, and the dimersal fish that have limited movement. Feedback given is that provincial governments do mangrove reforestation along the coast and estuaries, and create marine conservation areas determination of areas (KKLD) in the strait Dompak water. Key Words : heavy metals, marine life, coastal water of tanjungpinang, mangrove

Study on the Optimization Design of TWC Based on Chemical Reaction Kinetics Simulation

Based on the simulation of exhaust gas after-treatment established by GT-Power, the washcoat partition approach has been studied both experimentally and by numerical modeling. It shows that, as the mass of noble metal keeping constant, the washcoat partition approach, in which the substrate is equally separated into two partitions and the concentration ratio of precious metal between the two partitions is 4:1, presents the content of CH, 0.037g/km, in exhaust has been decreased in 26.7% comparing to the non-partition approach.

Study of Complexation Equilibria Between the Iron(III) Ion and 2-Hydroxybenzamide in Aqueous Solution

The complexation of the Fe3+ ion with 2-hydroxybenzamide (salicylamide, HL) has been studied, at 25.0 °C, by potentiometric measurements with a glass electrode in 1 mol·dm−3 NaClO4 medium. The concentration of salicylamide (C L) has been varied between (1 × 10−3 and 10 × 10−3) mol·dm−3, while the concentration of metal cation (C M) ranged within (0.5 × 10−3 and 10 × 10−3) mol·dm−3. The ligand to metal concentration ratio has been varied between 1 and 10 and the hydrogen ion concentration was decreased stepwise until the incipient precipitation of a basic salt of the metal, which occurred at different values depending on the specific ligand to metal ratio. The experimental data were consistent with the formation of the complexes FeL2+, Fe(HL)L2+ and $$ {\text{FeL}}_{2}^{ + } $$ . Equilibrium formation constants have been given for the investigated ionic medium as well as for the infinite dilution reference state, evaluated according to the Specific Interaction Theory. The predominant species in neutral solution are $$ {\text{FeL}}_{2}^{ + } $$ and $$ {\text{Fe}}\left( {\text{OH}} \right)_{2}^{ + } $$ .

Evaluation of Metals Bioavailability in Agricultural Soil Treated with Wood Ash

In the present work, we aimed to study the effect of quantitative changes of micronutrients (Cu, Zn, Mn) in soil and plants caused by wood ash applied into the soil in increasing doses. A pot experiment with medium textured soil, white mustard as a test plant and six amendment treatments (doses of wood ash: 0, 1, 5, 10, 20, 30 Mg·ha-1) was performed. Total contents of Cu, Zn and Mn were determined in soil and plant samples. Single (DTPA and HCl) and sequential (BCR) extractions were used to evaluate the available amounts of metals and their distribution in fractions. A plant’s ability to accumulate metals from soils was estimated using the bioconcentration factor (BCF), which is defined as the ratio of metal concentration in the plants to that in soil. The increasing doses of wood ash increased total and available contents of trace elements, especially Cu and Mn. The distribution of metals among particular fractions depended mainly on their geochemical character. The highest content of Cu was found in the reducible and oxidisable fractions, whereas, the greatest amounts of Zn and Mn were in the exchangeable and reducible fractions, and the lowest in the oxidisable fraction. Despite small wood ash influence on metal distribution in the individual soil fractions, increasing doses of wood ash increased the amounts of Cu, Zn, Mn in easily soluble fractions, which are potentially available to plants. As a result of wood ash increasing doses application, the higher amounts of Cu, Zn and Mn in plant tissues were found. However, only in the case of Zn, the value of BCF indicated on such accumulation in the plants.

Examination of flotation behavior of metal ions for process water remediation

Solutions containing low concentrations of heavy metal could be produced from any industrial processes and it is important to remove these ions from aqueous solution due to environmental regulations. In this paper, ion flotation method is employed to remove metal ions such as copper, lead, zinc, cadmium and nickel from aqueous solution. Firstly, several parameters such as pH, concentration and type of surfactants were investigated along with copper. After, ion flotation was tested on multiple ions individually and collectively, in different type of flotation machines. The best conditions were found as pH9, with 1:1 ratio of sodium dodecyl sulfate and metal concentration, 20mg/L each metal concentration, 3min flotation time. After flotation the remaining solution contained 0.5mg/L Cu, 2.5mg/L Pb, 2.6mg/L Ni, 3.4mg/L Cd, 1.5mg/L Zn. Ion flotation method can be used to clean process waters produced in flotation plants containing low metal concentrations. The overall method is suggested to remediate process waters generated flotation plants.

Ecological and human health risks associated with abandoned gold mine tailings contaminated soil.

Gold mining is a major source of metal and metalloid emissions into the environment. Studies were carried out in Krugersdorp, South Africa, to evaluate the ecological and human health risks associated with exposure to metals and metalloids in mine tailings contaminated soils. Concentrations of arsenic (As), cadmium (Cd), chromium (Cr), cobalt (Co), copper (Cu), lead (Pb), manganese (Mn), nickel (Ni), and zinc (Zn) in soil samples from the area varied with the highest contamination factors (expressed as ratio of metal or metalloid concentration in the tailings contaminated soil to that of the control site) observed for As (3.5x102), Co (2.8x102) and Ni (1.1x102). Potential ecological risk index values for metals and metalloids determined from soil metal and metalloid concentrations and their respective risk factors were correspondingly highest for As (3.5x103) and Co (1.4x103), whereas Mn (0.6) presented the lowest ecological risk. Human health risk was assessed using Hazard Quotient (HQ), Chronic Hazard Index (CHI) and carcinogenic risk levels, where values of HQ > 1, CHI > 1 and carcinogenic risk values > 1×10−4 represent elevated risks. Values for HQ indicated high exposure-related risk for As (53.7), Cr (14.8), Ni (2.2), Zn (2.64) and Mn (1.67). Children were more at risk from heavy metal and metalloid exposure than adults. Cancer-related risks associated with metal and metalloid exposure among children were also higher than in adults with cancer risk values of 3×10−2 and 4×10−2 for As and Ni respectively among children, and 5×10−3 and 4×10−3 for As and Ni respectively among adults. There is significant potential ecological and human health risk associated with metal and metalloid exposure from contaminated soils around gold mine tailings dumps. This could be a potential contributing factor to a setback in the health of residents in informal settlements dominating this mining area as the immune systems of some of these residents are already compromised by high HIV prevalence.

Comparison of chronic mixture toxicity of nickel-zinc-copper and nickel-zinc-copper-cadmium mixtures between Ceriodaphnia dubia and Pseudokirchneriella subcapitata.

Although aquatic organisms in the environment are exposed to mixtures of metals, risk assessment for metals is most commonly performed on a metal-by-metal basis. To increase the knowledge about chronic mixture effects, the authors investigated whether metal mixture effects are dependent on the biological species, mixture composition, and metal concentration ratio. The authors evaluated the effects of quaternary Ni-Zn-Cu-Cd and ternary Ni-Zn-Cu mixtures on 48-h algal growth rate (Pseudokirchneriella subcapitata) and 7-d daphnid reproduction (Ceriodaphnia dubia) using a ray design. Single metals were 3-fold to 42-fold more toxic for C. dubia than for P. subcapitata, based on the 50% effective concentration expressed as free metal activity, the range representing different metals. Statistical analysis of mixture effects showed that the ternary and quaternary mixture effects were antagonistic on algal growth relative to the concentration addition (CA) model, when the analysis was based on dissolved concentrations and on free metal ion activities. Using the independent action (IA) model, mixture effects in both rays were statistically noninteractive for algal growth when the analysis was based on dissolved concentrations; however, the interactions shifted toward antagonism when based on free ion activities. The ternary Ni-Zn-Cu mixture acted antagonistically on daphnid reproduction relative to both reference models, either expressed as free ion activities or dissolved concentrations. When Cd was added to the mixture, however, the mixture effects shifted toward noninteractivity for daphnids. The metal concentration ratio did not significantly influence the magnitude of observed antagonistic effects. Regardless of statistical interactions observed, based on the present study, CA and in most instances also IA can serve as a protective model for ternary Ni-Zn-Cu and quaternary Ni-Zn-Cu-Cd toxicity to both species. Environ Toxicol Chem 2017;36:1056-1066. © 2016 SETAC.

Development and validation of a metal mixture bioavailability model (MMBM) to predict chronic toxicity of Ni-Zn-Pb mixtures to Ceriodaphnia dubia

Recently, several bioavailability-based models have been shown to predict acute metal mixture toxicity with reasonable accuracy. However, the application of such models to chronic mixture toxicity is less well established. Therefore, we developed in the present study a chronic metal mixture bioavailability model (MMBM) by combining the existing chronic daphnid bioavailability models for Ni, Zn, and Pb with the independent action (IA) model, assuming strict non-interaction between the metals for binding at the metal-specific biotic ligand sites. To evaluate the predictive capacity of the MMBM, chronic (7d) reproductive toxicity of Ni-Zn-Pb mixtures to Ceriodaphnia dubia was investigated in four different natural waters (pH range: 7–8; Ca range: 1–2 mM; Dissolved Organic Carbon range: 5–12 mg/L). In each water, mixture toxicity was investigated at equitoxic metal concentration ratios as well as at environmental (i.e. realistic) metal concentration ratios. Statistical analysis of mixture effects revealed that observed interactive effects depended on the metal concentration ratio investigated when evaluated relative to the concentration addition (CA) model, but not when evaluated relative to the IA model. This indicates that interactive effects observed in an equitoxic experimental design cannot always be simply extrapolated to environmentally realistic exposure situations. Generally, the IA model predicted Ni-Zn-Pb mixture toxicity more accurately than the CA model. Overall, the MMBM predicted Ni-Zn-Pb mixture toxicity (expressed as % reproductive inhibition relative to a control) in 85% of the treatments with less than 20% error. Moreover, the MMBM predicted chronic toxicity of the ternary Ni-Zn-Pb mixture at least equally accurately as the toxicity of the individual metal treatments (RMSEMix = 16; RMSEZn only = 18; RMSENi only = 17; RMSEPb only = 23). Based on the present study, we believe MMBMs can be a promising tool to account for the effects of water chemistry on metal mixture toxicity during chronic exposure and could be used in metal risk assessment frameworks.

Characteristics of Respirable Particulate Metals Emitted by a Beehive Firework Display in YanShuei Area of Southern Taiwan

This study investigates metals in the PM_(1.0) and PM_(2.5) collected using a micro-orifice uniform deposition impactor (MOUDI) sampler in the YanShuei area of southern Taiwan during a beehive firework display. The results of sample analyses indicate that during the beehive firework display, the ratios of metal concentrations in PM_(2.5) (D) to the background level (B) at leeward sampling site were 1,828 for Ba, 702 for K, 534 for Sr, 473 for Cu, 104 for Mg, 121 for Al, and 98 for Pb. The corresponding data for PM_(1.0) were 3036, 838, 550, 676, 594, 190, and 126, respectively. According to the results of metal composition ratio, Principal Component Analysis (PCA), and upper continental crust (UCC) analyses, the concentrations of particle-bound Al, Ba, Cu, K, Mg, Pb, and Sr increased during the beehive firework displays, suggesting that firework-display aerosols contained abundant metal elements of Al, Ba, Cu, K, Mg, Pb, and Sr. Before (background), trial, during, and after the beehive firework display, the Ba, K, Cu, Mg, Pb, and Sr (commonly regarded as firework display indicator elements) accounted for 0.520, 2.45, 26.4 and 0.849% mass of PM1, respectively, while for PM_(2.5) the corresponding data were 0.777, 2.32, 23.8, and 0.776%, respectively.

Phytoremedial Potential of Typha latifolia, Eichornia crassipes and Monochoria hastata found in Contaminated Water Bodies Across Ranchi City (India)

Phytoremediation is an emerging technology that uses green plants (living machines) for removal of contaminants of concern (COC). These plant species have the potential to remove the COC, thereby restoring the original condition of soil or water environment. The present study focuses on assessing the heavy metals (COC) present in the contaminated water bodies of Ranchi city, Jharkhand, India. Phytoremedial potential of three plant species: Typha latifolia, Eichornia crassipes and Monochoria hastata were assessed in the present study. Heterogenous accumulation of metals was found in the three plant species. It was observed that the ratio of heavy metal concentration was different in different parts, i.e., shoots and roots. Positive results were also obtained for translocation factor of all species with minimum of 0.10 and maximum of 1. It was found experimentally that M. hastata has the maximum BFC for root as 4.32 and shoot as 2.70 (for Manganese). For T. latifolia, BCF of maximum was observed for root (163.5) and respective shoot 86.46 (for Iron), followed by 7.3 and 5.8 for root and shoot (for Manganese) respectively. E. crassipes was found to possess a maximum BCF of 278.6 (for Manganese and 151 (for Iron) and shoot as 142 (for Manganese) and 36.13 (for Iron).

Comparison of phytotoxicity of copper and nickel in soils with different Chinese plant species

Ecological risk assessment of metals in soils is important to develop the critical loads of metals in soils. Phytotoxicity is one of the endpoints for ecological risk assessment of soils contaminated with metals. The sensitivity of eight Chinese plant species (bok choy, mustard, tomato, green chilli, paddy rice, barley, spinach and celery) to copper (Cu) and nickel (Ni) toxicity in two Chinese soils was investigated to assess their potential use for ecological risk assessment in the region. The results showed that bok choy and mustard were the two most sensitive species to Cu and Ni toxicities. Assessment of metal accumulation by the plants demonstrated that bok choy shoot had the highest bioconcentration factor (BCF, the ratio of metal concentration in plant shoots to metal concentration in soil). Given the importance of bok choy to agricultural production in Asia, it is therefore important that these sensitive plant species are included in species sensitivity distributions for ecological risk assessment of Cu and Ni in soils.

UV spectrophotometric studies of Cu(II) ions separation by ultrafiltration enhanced with poly(sodium acrylate)

Polymer-enhanced ultrafiltration is an effective separation technique which enables heavy metal ions removal from aqueous solutions. In this work, a water soluble polymer containing carboxylic groups and poly(sodium acrylate) (PSA), was used to enhance the separation of Cu(II) ions during ultrafiltration. The UV spectrophotometric analysis of the solutions containing PSA and Cu(II) ions revealed an absorption band with its maximum at a wavelength of 255 nm. The methods of continuous variations (Job’s method) and molar ratio were employed to assess the stoichiometry of PSA–Cu(II) complexes formed. The molar ratio of PSA repeat unit to Cu(II) ion was evaluated to be ca. 2.8–2.9. The effect of the polymer—metal concentration ratio, solution pH, and the presence of anions: Cl-, SO42-, CO32-, PO43-, as well as a complexing agent (EDTA) on copper ions separation was investigated. The study revealed a good compatibility of spectrophotometric analysis and the ultrafiltration results.